WO2025026811A1

WO2025026811A1 - Polymer composition with recycled glass fibers

Info

Publication number: WO2025026811A1
Application number: PCT/EP2024/070830
Authority: WO
Inventors: Philippe Desbois
Original assignee: Basf Se
Priority date: 2023-07-28
Filing date: 2024-07-23
Publication date: 2025-02-06

Abstract

Herein a specific method for producing a polymer composition comprising recycled glass fibers and a specific polymer composition comprising recycled glass fibers are described.

Description

Polymer composition with recycled glass fibers

Polymer products, e.g., rotor blades of a wind power plant, can be recycled using different techniques, for example, mechanical or chemical recycling. The rotor blades commonly comprise a polymer and a reinforcement, e.g. glassfiber textiles comprising very long glass fibers. Besides the polymer itself also the reinforcement can be separated and collected, e.g., as described in WO2020212186 A1. While conventional glass fibers for use as reinforcement in polymer compounds are coated and assembled in compact bundles, the glass fibers obtained in a recycling process are uncoated and wool-like. As a consequence, the further processing to obtain polymer compounds comprising recycled glass fibers as reinforcement is challenging since the behavior of recycled wool-like glass fibers in the further processing is totally different compared to conventional bundled glass fibers. Thus, the object of the present invention is to provide an improved method for the production of a reinforced polymer compound or product comprising recycled glass fibers, in particular wherein the method is: fast, reproducible, and less susceptible to failure; and leads to a polymer compound PC1 or product PP1 having: a predefined amount of recycled glass fibers, a high amount of recycled glass fibers, a specific length of recycled glass fibers, improved mechanical properties, and/or, preferably and, improved sustainability.

This object is at least partially solved by a method comprising the steps: providing a mixture M1 comprising: a polymer P1 , and glass fibers GF1, preferably wherein the glass fibers GF1 are recycled glass fibers; and mixing the mixture M1 to obtain a polymer compound PC1 comprising the polymer P1 and glass fibers GFT, wherein a bulk density of the glass fibers GF1 is 0.70 g/cm³ or less, and/or wherein a length of the glass fibers GF1 is 30.0 mm or less.

In a preferred embodiment, the method comprises the step: converting the polymer compound PC1 to obtain a polymer product PP1 . For the converting step, common techniques, e.g., injection molding, well known to a person skilled in the art can be used.

The object is further at least partially solved by a polymer compound PC1 obtained by or obtainable by the method as described herein.

In a preferred embodiment, the polymer compound PC1 comprises: a polymer P1 , and glass fibers GF1'.

The object is further at least partially solved by a polymer product PP1 comprising the polymer compound PC1 as described herein.

Another aspect of the invention is the use of glass fibers GF1 for the production of a polymer compound PC1 and/or polymer product PP1 , wherein the bulk density of the glass fibers GF1 is 0.7 g/cm³ or less, and/or wherein the length of the glass fibers GF1 is 30.0 mm or less.

The mixing time is not particularly limited. Preferably, the mixing is performed for 5 s or more, preferably 15 s or more, more preferably 20 s or more, more preferably 30 s or more, more preferably 50 s or more, more preferably 75 s or more, more preferably 100 s or more, more preferably 120 s or more, and/or the mixing is performed for 60 min or less, preferably 10 min or less, more preferably 5 min or less, more preferably 4 min or less, more preferably 180 s or less, more preferably 150 s or less, more preferably 120 s or less, more preferably 100 s or less, more preferably 80 s or less, more preferably 60 s or less, more preferably 40 s or less. As longer the mixing time as better the glass fibers are uniformly distributed. In addition, if the mixing time is shorter, the mechanical properties of the polymer compound PC1 are improved. Thus, preferably the mixing is performed for 5 s or more, preferably 15 s or more, more preferably 20 s or more, more preferably 30 s or more, more preferably 50 s or more, and 60 min or less, preferably 10 min or less, more preferably 5 min or less, more preferably 4 min or less, more preferably 180 s or less, more preferably 150 s or less, more preferably 120 s or less, more preferably 100 s or less, more preferably 80 s or less.

In a preferred embodiment, the mixing is performed by an extruder, preferably a twin-screw extruder. Thus, the homogeneity in the polymer compound PC1 is improved.

The rotational speed of the extruder is not particularly limited. In a preferred embodiment, a rotational speed of the extruder is 1 U/min or more, preferably 10 U/Min or more, more preferably 50 U/min or more, more preferably 100 U/min or more, more preferably 150 U/min or more, more preferably 200 U/min or more, and/or a rotational speed of the extruder is 500 U/min or less, preferably 400 U/Min or less, more preferably 350 U/min or less, more preferably 300 U/min or less, more preferably 250 U/min or less, more preferably 200 U/min or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

The flow rate in the extruder is not particularly limited. Preferably, the flowrate, preferably in the extruder, is 10 g/h or more, preferably 50 g/h or more, more preferably 100 g/h or more, more preferably 500 g/h or more, more preferably 1000 g/h or more, more preferably 1500 g/h or more, more preferably 2000 g/h or more, more preferably 3000 g/h or more, more preferably 5000 g/h or more, more preferably 5000 kg/h or more, more preferably 10000 kg/h or more, more preferably 15000 kg/h or more, and/or the flowrate, preferably in the extruder, is 20000 kg/h or less, preferably 15000 kg/h or less, more preferably 10000 kg/h or less, more preferably 5000 kg/h or less, more preferably 2500 kg/h or less, more preferably 20000 g/h or less, more preferably 10000 kg/h or less, more preferably 7500 kg/h or less, more preferably 5000 kg/h or less, more preferably 4000 kg/h or less, more preferably 3000 kg/h or less, more preferably 2500 kg/h or less, more preferably 2000 kg/h or less, more preferably 1500 kg/h or less, more preferably 1000 kg/h or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

The adjusted temperature during the mixing is not particularly limited. Preferably, the mixing is performed at Tm of polymer P1 or more, preferably (Tm of polymer P1 (in °C) + 10 °C) or more, more preferably (Tm of polymer P1 + 20 °C) or more, more preferably (Tm of polymer P1 + 30 °C) or more, more preferably (Tm of polymer P1 + 40 °C) or more, more preferably (Tm of polymer P1 + 50 °C) or more, and/or the mixing is performed at (Tm of polymer P1 + 100 °C) or less, preferably (Tm of polymer P1 + 90 °C) or less, more preferably (Tm of polymer P1 + 80 °C) or less, more preferably (Tm of polymer P1 + 70 °C) or less, more preferably (Tm of polymer P1 + 60 °C) or less, more preferably (Tm of polymer P1 + 50 °C) or less, more preferably (Tm of polymer P1 + 40 °C) or less, more preferably (Tm of polymer P1 + 30 °C) or less, more preferably (Tm of polymer P1 + 20 °C) or less, more preferably (Tm of polymer P1 + 10 °C) or less. If the temperature is high, e.g. Tm of polymer P1 or more, preferably (Tm of polymer P1 + 10 °C) or more, more preferably (Tm of polymer P1 + 20 °C) or more, more preferably (Tm of polymer P1 + 30 °C) or more, more preferably (Tm of polymer P1 + 40 °C) or more, more preferably (Tm of polymer P1 + 50 °C) or more, the susceptibility to failure of the method is reduced. If the temperature is low, e.g., (Tm of polymer P1 + 100 °C) or less, preferably (Tm of polymer P1 + 90 °C) or less, more preferably (Tm of polymer P1 + 80 °C) or less, more preferably (Tm of polymer P1 + 70 °C) or less, more preferably (Tm of polymer P1 + 60 °C) or less, more preferably (Tm of polymer P1 + 50 °C) or less, more preferably (Tm of polymer P1 + 40 °C) or less, more preferably (Tm of polymer P1 + 30 °C) or less, more preferably (Tm of polymer P1 + 20 °C) or less, more preferably (Tm of polymer P1 + 10 °C) or less, the mechanical properties of the polymer compound PC1 are improved. More preferably, the temperature is Tm of polymer P1 or more, preferably (Tm of polymer P1 + 10 °C) or more, more preferably (Tm of polymer P1 + 20 °C) or more, more preferably (Tm of polymer P1 + 30 °C) or more, and (Tm of polymer P1 + 100 °C) or less, preferably (Tm of polymer P1 + 90 °C) or less, more preferably (Tm of polymer P1 + 80 °C) or less, more preferably (Tm of polymer P1 + 70 °C) or less, more preferably (Tm of polymer P1 + 60 °C) or less, more preferably (Tm of polymer P1 + 50 °C) or less, more preferably (Tm of polymer P1 + 40 °C) or less, more preferably (Tm of polymer P1 + 30 °C) or less. Thus, the mechanical properties of the polymer compound PC1 are improved and the susceptibility to failure of the method is reduced. The temperature described herein is the temperature of the barrel, e.g. the barrel temperature of the extruder. A person skilled in the art knows that the temperature of the polymer compound may vary, for example ±5°C, preferably ±2°C.

In another preferred embodiment, the mixing is performed at 220 °C or more, preferably 230 °C or more, more preferably 240 °C or more, more preferably 250 °C or more, more preferably 260 °C or more, more preferably 270 °C or more, more preferably 280 °C or more and/or the mixing is performed at 350 °C or less, preferably 300 °C or less, more preferably 290 °C or less, more preferably 270 °C or less, more preferably 260 °C or less, more preferably 250 °C or less, more preferably 240 °C or less. If the temperature is high, e.g. 220 °C or more, preferably 230 °C or more, more preferably 240 °C or more, more preferably 250 °C or more, more preferably 260 °C or more, more preferably 270 °C or more, more preferably 280 °C or more, the susceptibility to failure of the method is reduced. If the temperature is low, e.g., 350 °C or less, preferably 300 °C or less, more preferably 290 °C or less, more preferably 270 °C or less, more preferably 260 °C or less, more preferably 250 °C or less, more preferably 240 °C or less, the mechanical properties of the polymer composition PC1 are improved. More preferably, the temperature is 220 °C or more, preferably 230 °C or more, more preferably 240 °C or more, more preferably 250 °C or more, more preferably 260 °C or more, and 350 °C or less, preferably 300 °C or less, more preferably 290 °C or less, more preferably 270 °C or less, more preferably 260 °C or less. Thus, the mechanical properties of the polymer compound PC1 are improved and the susceptibility to failure of the method is reduced. The temperature described herein is the temperature of the barrel, e.g. the barrel temperature of the extruder. A person skilled in the art knows that the temperature of the polymer compound may vary, for example ±5°C, preferably ±2°C.

The time and place of adding the glass fibers to the polymer is not particularly limited. Preferably, the glass fibers GF1 are added to the polymer P1 in the extruder. Thus, the consistency of the amount of glass fibers in the polymer compound PC1 can be improved and the amount of glass fibers in the polymer compound PC1 is increased.

The amount of glass fibers added per unit of time is not particularly limited. Preferably, the glass fibers GF1 are added to the polymer P1 in the extruder within 1 kg/min or more, preferably 5 kg/min or more, more preferably 10 kg/min or more, more preferably 30 kg/min or more, more preferably 60 kg/min or more and/or the glass fibers GF1 were added to the polymer P1 in the extruder within 120 kg/min or less, more preferably 60 kg/min or less, more preferably 40 kg/min or less, more preferably 20 kg/min or less, more preferably 15 kg/min or less, more preferably 8 kg/min or less. If the amount per time is high, the mechanical properties of the polymer are increased. If the amount per time is low, the mechanical properties of the polymer compound PC1 are improved and the susceptibility to failure of the method is reduced.

In a preferred embodiment, the glass fibers GF1 are recycled glass fibers, preferably recycled glass fiber yarns, rovings, recycled glass fiber textiles and/or fabrics, more preferably recycled glass fiber yarns, rovings and/or recycled glass fiber textiles, more preferably woven, non-woven, matt or multiaxial. Preferably, herein recycled glass fibers are glass fibers which were embedded in a polymer compound comprising a polymer and then, the polymer was at least partially removed, preferably removed.

The bulk density of the glass fibers is not particularly limited. Preferably, the bulk density of the glass fibers GF1 is 0.05 g/cm³ or more, preferably 0.10 g/cm³ or more, more preferably 0.15 g/cm³ or more, more preferably 0.20 g/cm³ or more, more preferably 0.22 g/cm³ or more, more preferably 0.25 g/cm³ or more, more preferably 0.30 g/cm³ or more, more preferably 0.35 g/cm³ or more, more preferably 0.50 g/cm³ or more, and/or the bulk density of the glass fibers GF1 is 0.70 g/cm³ or less, preferably 0.60 g/cm³ or less, more preferably 0.50 g/cm³ or less, more preferably 0.40 g/cm³ or less, more preferably 0.30 g/cm³ or less, more preferably 0.25 g/cm³ or less, more preferably 0.20 g/cm³ or less, more preferably 0.15 g/cm³ or less, more preferably 0.10 g/cm³ or less. If the bulk density is high, e.g., 0.05 g/cm³ or more, preferably 0.10 g/cm³ or more, more preferably 0.15 g/cm³ or more, more preferably 0.20 g/cm³ or more, more preferably 0.22 g/cm³ or more, more preferably 0.25 g/cm³ or more, more preferably 0.30 g/cm³ or more, more preferably 0.35 g/cm³ or more, more preferably 0.50 g/cm³ or more, the amount of the glass fibers in the polymer compound PC1 can be increased, e.g. up to 30 weight-% and the speed of the method is improved. If the bulk density is low, e.g., 0.70 g/cm³ or less, preferably 0.60 g/cm³ or less, more preferably 0.50 g/cm³ or less, more preferably 0.40 g/cm³ or less, more preferably 0.30 g/cm³ or less, more preferably 0.25 g/cm³ or less, more preferably 0.20 g/cm³ or less, more preferably 0.15 g/cm³ or less, more preferably 0.10 g/cm³ or less, the reproducibility is improved, the susceptibility to failure of the method is reduced, and the polymer compound PC1 has an improved predefined amount of glass fibers.

The length of the glass fibers GF1 which are mixed with the polymer P1 is not particularly limited. Preferably, the length of the glass fibers GF1 is 0.01 mm or more, preferably 0.05 mm or more, more preferably 0.1 mm or more, more preferably 0.10 mm or more, more preferably 0.15 mm or more, more preferably 0.2 mm or more, more preferably 0.20 mm or more, more preferably 0.25 mm or more, more preferably 0.3 mm or more, more preferably 0.30 mm or more, more preferably 0.35 mm or more, more preferably 0.4 mm or more, more preferably 0.40 mm or more, more preferably 0.45 mm or more, more preferably 0.5 mm or more, more preferably 0.6 mm or more, more preferably 0.7 mm or more, more preferably 0.8 mm or more, more preferably 0.9 mm or more, more preferably 1.0 mm or more, more preferably 1.5 mm or more, more preferably 2.5 mm or more, more preferably 5.0 mm or more, more preferably 7.5 mm or more, more preferably 10.0 mm or more, more preferably 15.0 mm or more, and/or the length of the glass fibers GF1 is 30.0 mm or less, preferably 25.0 mm or less, more preferably 20.0 mm or less, more preferably 17.5 mm or less, more preferably 15.0 mm or less, more preferably 12.5 mm or less, more preferably 10.0 mm or less, more preferably 7.5 mm or less, more preferably 5.0 mm or less, more preferably 4.0 mm or less, more preferably 3.9 mm or less, more preferably 3.5 mm or less, more preferably 3.0 mm or less, more preferably 2.0 mm or less, more preferably 1 .0 mm or less, more preferably 0.9 mm or less, more preferably 0.8 mm or less, more preferably 0.7 mm or less, more preferably 0.6 mm or less, more preferably 0.5 mm or less, more preferably 0.4 mm or less, more preferably 0.3 mm or less, more preferably 0.2 mm or less, more preferably 0.1 mm or less. If the fiber length is short, e.g., 30.0 mm or less, preferably 25.0 mm or less, more preferably 20.0 mm or less, more preferably 17.5 mm or less, more preferably 15.0 mm or less, more preferably 12.5 mm or less, more preferably 10.0 mm or less, more preferably 7.5 mm or less, more preferably 5.0 mm or less, more preferably 4.0 mm or less, more preferably 3.9 mm or less, more preferably 3.5 mm or less, more preferably 3.0 mm or less, more preferably 2.0 mm or less, more preferably 1.0 mm or less, more preferably 0.9 mm or less, more preferably 0.8 mm or less, more preferably 0.7 mm or less, more preferably 0.6 mm or less, more preferably 0.5 mm or less, more preferably 0.4 mm or less, more preferably 0.3 mm or less, more preferably 0.2 mm or less, more preferably 0.1 mm or less, the mechanical properties of the polymer compound PC1 are increased and the reproducibility of the method is improved. If the fiber length is long, e.g., 0.01 mm or more, preferably 0.05 mm or more, more preferably 0.1 mm or more, more preferably 0.2 mm or more, more preferably 0.3 mm or more, more preferably 0.4 mm or more, more preferably 0.5 mm or more, more preferably 0.6 mm or more, more preferably 0.7 mm or more, more preferably 0.8 mm or more, more preferably 0.9 mm or more, more preferably 1 .0 mm or more, more preferably 1.5 mm or more, more preferably 2.5 mm or more, more preferably 5.0 mm or more, more preferably 7.5 mm or more, more preferably 10.0 mm or more, more preferably 15.0 mm or more, the length of the glass fibers in the polymer compound PC1 is increased and the susceptibility to failure of the method is reduced. The inventors recognized, that especially if the length of the glass fibers GF1 is long, preferably 0.15 mm or more, more preferably 0.2 mm or more, more preferably 0.20 mm or more, more preferably 0.25 mm or more, more preferably 0.3 mm or more, more preferably 0.30 mm or more, more preferably 0.35 mm or more, more preferably 0.4 mm or more, more preferably 0.40 mm or more, more preferably 0.45 mm or more, more preferably 0.5 mm or more, more preferably 0.6 mm or more, more preferably 0.7 mm or more, more preferably 0.8 mm or more, more preferably 0.9 mm or more, more preferably 1.0 mm or more, more preferably 1.5 mm or more, more preferably 2.5 mm or more, more preferably 5.0 mm or more, more preferably 7.5 mm or more, more preferably 10.0 mm or more, more preferably 15.0 mm or more, and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, an orientation of the glass fibers GF1 is predominantly isotropic, preferably isotropic and/or the shape of the glass fibers GF1 is wool-like and/or the glass fibers GF1 are obtainable or obtained from a polymer product PP2 comprising a polymer P2 and glass fibers GF1", preferably wherein a length of the glass fibers GF1” is 30 mm or more, preferably 100 mm or more and/or wherein the glass fibers GF1” are glass-fiber textiles. Conventional and non-recycled glass fibers are coated and assembled in compact bundles (=isotropic).

The method to recycle the glass fibers is not particularly limited. Preferably, the glass fibers GF1 are obtained or obtainable by a method comprising the following step(s): preferably milling, crushing and/or shredding, more preferably crushing and/or shredding, a/the polymer product PP2 comprising a polymer P2 and glass fibers GF1 ", preferably wherein the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more, annealing a/the polymer product PP2 comprising a/the polymer P2 and glass fibers GF1”, preferably wherein one or more, preferably all, of the following conditions is/are fulfilled: the temperature is at least once 250 °C or more and 1000 °C or less, preferably 320 °C or more and 800 °C or less, more preferably 350 °C or more and 800 °C or less, more preferably 450 °C or more and 600 °C or less; the annealing time is 0.1 h or more and 48 h or less, preferably 0.5 h or more and 24 h or less, more preferably 2 h or more and 6 h or less; and/or the annealing is performed in the presence of air, CO2, N2, Ar, or mixtures thereof, preferably air; and preferably and cutting, chopping and/or filtering, preferably through a sieve, more preferably through a sieve of 10 mm (mesh size) or less, more preferably 8 mm or less, more preferably 6 mm or less, more preferably 5 mm or less, more preferably 3 mm or less, more preferably 2 mm or less, more preferably 1 mm or less, the glass fibers GF1” after annealing to obtain the glass fibers GF1 ; preferably and wherein the glass fibers GF1” are glass fiber roving and/or glass fiber textiles. Thus, glass fibers GF1 , exhibiting the specific length and other parameters described herein, can be obtained. This is particularly true, if the glass fibers are filtered, preferably through a sieve, more preferably through a sieve of 10 mm (mesh size) or less, more preferably 8 mm or less, more preferably 6 mm or less, more preferably 5 mm or less, more preferably 3 mm or less, more preferably 2 mm or less, more preferably 1 mm or less, after annealing, preferably after annealing; and cutting and/or chopping.

In a preferred embodiment, an age of the polymer product PP2 is 1 year or more, preferably 5 years or more, more preferably 10 years or more, more preferably 20 years or more.

In a preferred embodiment, the glass fibers GF1 are etched and/or corroded.

In a preferred embodiment, a BET value [m²/g] and/or a disperse surface energy [mJ/m²] of glass fibers GF1 and glass fiber GFT; and/or glass fibers GF1 and glass fiber GF1”; and/or glass fibers GFT and glass fiber GF1” are not the same.

The glass fibers GF1 might be coated or uncoated. In a preferred embodiment, the glass fibers GF1 are uncoated. Conventional and non-recycled glass fibers for polymer compound PC1s are coated, e.g. with a silane coating, a polyurethane and/or an epoxy coating.

The better the recycling method, the less polymer sticks to the glass fibers which are mixed with the polymer. The organic content of the glass fibers GF1 is not particularly limited. Preferably, an organic content of the glass fibers GF1 is 1 weight-% or less, preferably 0.9 weight-% or less, more preferably 0.8 weight-% or less, more preferably

0.7 weight-% or less, more preferably 0.6 weight-% or less, more preferably 0.5 weight-% or less, more preferably

0.4 weight-% or less, more preferably 0.3 weight-% or less, more preferably 0.2 weight-% or less, more preferably

0.1 weight-% or less, more preferably 0.05 weight-% or less, more preferably 0.03 weight-% or less, more preferably

0.01 weight-% or less. Thus, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to breakdown of the method is improved.

In a preferred embodiment, the glass fibers GF1 are recycled glass fibers.

A person skilled in the art understands that the length of glass fibers may change in a processing step, e.g. mixing or filtering. For this reason, a person skilled in the art understands that the length of the glass fibers GF1 is equal or longer than the length of the glass fibers GFT.

The length of the glass fibers GFT in the polymer compound PC1 is not particularly limited. Preferably, dO.10i_ength of the glass fibers GFT is 20 pm or more, preferably 30 pm or more, more preferably 40 pm or more, more preferably 50 pm or more, more preferably 70 pm or more, more preferably 100 pm or more, more preferably 110 m or more, more preferably 120 pm or more, more preferably 130 pm or more, more preferably 150 pm or more, more preferably 170 pm or more, more preferably 180 pm or more, and/or dO.10i_ength of the glass fibers GFT is 250 pm or less, preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 160 pm or less, more preferably 140 pm or less, more preferably 130 pm or less, more preferably 120 pm or less, more preferably 110 pm or less, more preferably 100 pm or less, more preferably 75 pm or less, more preferably 50 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved. Especially, if the length is short, e.g., 170 pm or less, preferably 160 pm or less, more preferably 140 pm or less, more preferably 130 pm or less, more preferably 120 pm or less, more preferably 110 pm or less, more preferably 100 pm or less, more preferably 75 pm or less, more preferably 50 pm or less, the mechanical properties are improved.

In a preferred embodiment, dO.IOfrequency of the glass fibers GFT is 20 pm or more, preferably 30 pm or more, more preferably 33 pm or more, more preferably 35 pm or more, more preferably 40 pm or more, more preferably 43 pm or more, more preferably 45 pm or more, more preferably 50 pm or more, more preferably 55 pm or more, and/or dO.IOfrequency of the glass fibers GFT is 100 pm or less, preferably 90 pm or less, more preferably 80 pm or less, more preferably 70 pm or less, more preferably 60 pm or less, more preferably 50 pm or less, more preferably 45 pm or less, more preferably 42 pm or less, more preferably 40 pm or less, more preferably 35 pm or less, more preferably 32 pm or less, more preferably 30 pm or less, more preferably 25 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved. Especially, if the length is short, e.g. 45 pm or less, preferably 42 pm or less, more preferably 40 pm or less, more preferably 35 pm or less, more preferably 32 pm or less, more preferably 30 pm or less, more preferably 25 pm or less, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, d0.50i_ength of the glass fibers GFT is 150 pm or more, preferably 160 pm or more, more preferably 200 pm or more, more preferably 250 pm or more, more preferably 260 pm or more, more preferably 300 pm or more, more preferably 350 pm or more, more preferably 370 pm or more, more preferably 400 pm or more, more preferably 450 pm or more, and/or d0.50i_ength of the glass fibers GFT is 800 pm or less, preferably 500 pm or less, more preferably 470 pm or less, more preferably 460 pm or less, more preferably 400 pm or less, more preferably 360 pm or less, more preferably 350 pm or less, more preferably 300 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 180 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved. Especially, if the length is short, e.g., 460 pm or less, preferably 400 pm or less, more preferably 360 pm or less, more preferably 350 pm or less, more preferably 300 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 180 pm or less, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, dO.SOfrequency of the glass fibers GFT is 40 pm or more, preferably 50 pm or more, more preferably 60 pm or more, more preferably 100 pm or more, more preferably 150 pm or more, more preferably 180 pm or more, more preferably 190 pm or more, more preferably 200 pm or more, more preferably 220 pm or more, more preferably 250 m or more, and/or dO.SOtrequency of the glass fibers GFT is 500 pm or less, preferably 300 pm or less, more preferably 260 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 150 pm or less, more preferably 100 pm or less, more preferably 60 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved. Especially, if the length is short, e.g. 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 150 pm or less, more preferably 100 pm or less, more preferably 60 pm or less, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, <100 pmi_ength of the glass fibers GFT is 5.0 % or more, preferably 5.5 % or more, more preferably 6.0 % or more, more preferably 6.5 % or more, more preferably 7.0 % or more, more preferably 7.5 % or more, more preferably 10.0 % or more, more preferably 20.0 % or more, more preferably 30.0 % or more, more preferably 35.0 % or more, and/or <100 pmi_ength of the glass fibers GFT is 50.0 % or less, preferably 50 % or less, more preferably 40.0 % or less, more preferably 35.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less, more preferably 8.0 % or less, more preferably 7.0 % or less, more preferably 6.0 % or less, more preferably 5.5 % or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, <100 pimtrequency of the glass fibers GFT is 15.0 % or more, preferably 20.0 % or more, more preferably 25.0 % or more, more preferably 29.0 % or more, more preferably 30.0 % or more, more preferably 31.0 % or more, more preferably 35.0 % or more, more preferably 40.0 % or more, more preferably 60.0 % or more, more preferably 70.0 % or more, and/or <100 pimtrequency of the glass fibers GFT is 100.0 % or less, preferably 80 % or less, more preferably 70.0 % or less, more preferably 50.0 % or less, more preferably 35.0 % or less, more preferably 31.0 % or less, more preferably 30.0 % or less, more preferably 29.0 % or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, <200 pimi_ength of the glass fibers GFT is 10.0 % or more, preferably 12.0 % or more, more preferably 15.0 % or more, more preferably 20.0 % or more, more preferably 30.0 % or more, more preferably 50.0 % or more, more preferably 55.0 % or more, and/or <200 pimi_ength of the glass fibers GFT is 100.0 % or less, preferably 75 % or less, more preferably 60.0 % or less, more preferably 55.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, <200 pimtrequency of the glass fibers GFT is 40.0 % or more, preferably 45.0 % or more, more preferably 50.0 % or more, more preferably 60.0 % or more, more preferably 70.0 % or more, more preferably 80.0 % or more, more preferably 85.0 % or more, and/or <200 imtrequency of the glass fibers GFT is 100.0 % or less, preferably 85 % or less, more preferably 60.0 % or less, more preferably 55.0 % or less, more preferably 50.0 % or less, more preferably 45.0 % or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

The kind of polymer is not particularly limited. It can be selected from thermoset, thermoplastic and elastomer. Preferably, polymer P1 is a thermoplastic polymer. Thus, the mixing of the glass fibers and the polymer is simplified and the mechanical properties of the polymer compound PC1 are improved.

Preferably, the polymer P1 and/or P2 is and/or the polymer product PP1 and/or PP2 comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (PU), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1 ,4-isoprene), poly(trans-1 ,4-isoprene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate coterephthalate (PBAT), polyester (PES), polyether sulfone (PESU), polyhydroxyalkanoate (PHA), poly-3-hydroxybutyrate (P3HB), poly-4- hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSU), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymer or mixture thereof, preferably polyamide (PA); preferably PA 6 or PA 66 or mixtures thereof. Especially, if the polymer is polyamide, preferably PA 6 or PA 66, the mechanical properties of the polymer compound PC1 are improved.

The content of the glass fibers is not particularly limited. Preferably, a content of the glass fiber GF1 and/or GFT in the mixture M1 , polymer compound PC1 or polymer product PP1 is 1 weight-% or more, preferably 2 weight-% or more, more preferably 3 weight-% or more, more preferably 4 weight-% or more, more preferably 5 weight-% or more, more preferably 10 weight-% or more, more preferably 15 weight-% or more, more preferably 20 weight-% or more, more preferably 21 weight-% or more, more preferably 25 weight-% or more, more preferably 30 weight- % or more, more preferably 35 weight-% or more, more preferably 40 weight-% or more, more preferably 45 weight- % or more, and/or a content of the glass fiber GF1 and/or GFT in the mixture M1 , polymer compound PC1 or polymer product PP1 is 50 weight-% or less, preferably 45 weight-% or less, more preferably 40 weight-% or less, more preferably 35 weight-% or less, more preferably 30 weight-% or less, more preferably 25 weight-% or less, more preferably 20 weight-% or less, more preferably 15 weight-% or less, more preferably 10 weight-% or less, more preferably 5 weight-% or less. The inventor recognized that surprisingly if the bulk density of the glass fibers GF1 is as described herein, the content of glass fibers GFT in the polymer compound PC1 can be increased, e.g., 10 weight-% or more, preferably 15 weight-% or more, more preferably 20 weight-% or more, more preferably 25 weight-% or more, more preferably 30 weight-% or more, more preferably 35 weight-% or more, more preferably 40 weight-% or more, more preferably 45 weight-% or more; and thus, the mechanical properties of the polymer compound PC1 are improved. Especially, if the content is 21 weight-% or more, preferably 25 weight-% or more, more preferably 30 weight-% or more, more preferably 35 weight-% or more, more preferably 40 weight-% or more, the mechanical properties of the polymer composition PC1 are improved. In addition, especially if the content is 50 weight-% or less, preferably 45 weight-% or less, more preferably 40 weight-% or less, more preferably 35 weight- % or less, more preferably 30 weight-% or less, more preferably 25 weight-% or less, more preferably 20 weight- % or less, the susceptibility to breakdown of the method is improved.

The content of the polymer P1 in the polymer compound PC1 is not particularly limited. Preferably, a content of the polymer P1 in the mixture M 1 , polymer compound PC1 or polymer product PP1 is 1 weight-% or more, preferably 2 weight-% or more, more preferably 3 weight-% or more, more preferably 4 weight-% or more, more preferably 5 weight-% or more, more preferably 10 weight-% or more, more preferably 15 weight-% or more, more preferably 20 weight-% or more, more preferably 25 weight-% or more, more preferably 30 weight-% or more, more preferably

35 weight-% or more, more preferably 40 weight-% or more, more preferably 45 weight-% or more, and/or a content of polymer P1 in the mixture M1 , polymer compound PC1 or polymer product PP1 is 99 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 85 weight-% or less, more preferably

80 weight-% or less, more preferably 75 weight-% or less, more preferably 50 weight-% or less, more preferably

35 weight-% or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, polymer P1 is at least partially recycled and/or biobased. Thus, the sustainability of the polymer compound PC1 is improved.

In a preferred embodiment the content of the polymer(s) and/or the glass fibers and/or the one or more additive(s) is/are determined based on identity preservation and/or segregation and/or mass balance and/or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard. These methods are well-known to a person skilled in the art and are, for example, described in detail in WC2023112013, which is incorporated herein by reference. Preferably, the content of the polymer(s) and/or the glass fibers and/or the one or more additive(s) is/are determined based on a method as described in WC2023112013.

To the mixture M1 and/or to the polymer compound PC1 one or more additives may be added. Thus, preferably the polymer compound PC1 or polymer product PP1 comprises one or more additive(s), more preferably the one or more additive(s) is/are selected from fiber(s), antioxidating agent(s), stabilizer(s), lubricant(s), mineral(s), colorant(s), pigment(s), dye(s), soot, talc, carbon black, bio additive(s), plasticizer(s), flame retardant(s), and mixtures thereof.

In a preferred embodiment, the polymer compound PC1 and/or the polymer product PP1 comprises, preferably consist of, polymer P1 , glass fibers GFT and one or more additive(s). Thus, the mechanical properties of the polymer compound PC1 are improved. In a preferred embodiment, the polymer compound PC1 and/or the polymer product PP1 and/or PP2 is/are or is/are a part of: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for light-emitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall.

In a preferred embodiment, a Young's modulus of the polymer compound PC1 and/or polymer product PP1 is/are 6.00*10^A3 MPa or more, preferably 6.10*10^A3 MPa or more, more preferably 6.20*10^A3 MPa or more, more preferably 6.30*10^A3 MPa or more, more preferably 6.40*10^A3 MPa or more, more preferably 6.50*10^A3 MPa or more, more preferably 7.00*10^A3 MPa or more, more preferably 7.50*10^A3 MPa or more, more preferably 8.00*10^A3 MPa or more, more preferably 8.50*10^A3 MPa or more, more preferably 8.90*10^A3 MPa or more, and/or a Young's modulus of the polymer compound PC1 and/or polymer product PP1 is/are 3.00*10^A4 MPa or less, preferably 2.50*10^A4 MPa or less, more preferably 2.00*10^A4 MPa or less, more preferably 1.50*10^A4 MPa or less, more preferably 1.00*10^A4 MPa or less, more preferably 9.50*10^A3 MPa or less, more preferably 9.00*10^A4 MPa or less, more preferably 8.00*10^A4 MPa or less, more preferably 7.00*10^A4 MPa or less, more preferably 6.50*10^A4 MPa or less, more preferably 6.20*10^A4 MPa or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, a tensile strength of the polymer compound PC1 and/or polymer product PP1 is 90 MPa or more, preferably 95 MPa or more, more preferably 100 MPa or more, more preferably 110 MPa or more, more preferably 120 MPa or more, more preferably 130 MPa or more, and/or a tensile strength of the polymer compound PC1 and/or polymer product PP1 is 200 MPa or less, preferably 180 MPa or less, more preferably 160 MPa or less, more preferably 140 MPa or less, more preferably 130 MPa or less, more preferably 125 MPa or less, more preferably 120 MPa or less, more preferably 115 MPa or less, more preferably 110 MPa or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, an elongation at break at room temperature of the polymer compound PC1 and/or polymer product PP1 is 2.0 % or more, preferably 2.5 % or more, more preferably 2.8 % or more, more preferably 3.0 % or more, more preferably 3.2 % or more, more preferably 3.5 % or more, and/or an elongation at break at room temperature of the polymer compound PC1 and/or polymer product PP1 is 5.0 % or less, preferably 4.0 % or less, more preferably 3.5 % or less, more preferably 3.3 % or less, more preferably 3.1 % or less, more preferably 2.9 % or less, more preferably 2.7 % or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, the method can be performed fast, is reproducible, and/or, preferably and, is less susceptible to failure, preferably is reproducible, and/or is less susceptible to failure.

In a preferred embodiment, the polymer compound PC1 and/or the polymer product PP1 exhibits a predefined amount of recycled glass fibers GFT, a high amount of recycled glass fibers GFT, a specific length of recycled glass fibers GFT, improved mechanical properties, and/or, preferably and, improved sustainability, preferably a predefined amount of recycled glass fibers GFT, a high amount of recycled glass fibers GFT, and/or a specific length of recycled glass fibers GFT.

In a preferred embodiment, the length of the glass fibers GFT is 100 pm or more, preferably 150 pm or more, more preferably 175 pm or more, more preferably 200 pm or more, more preferably 230 pm or more. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, the length of the glass fibers GFT is 1000 pm or less, preferably 900 pm or less, more preferably 800 pm or less, more preferably 700 pm or less, more preferably 600 pm or less, more preferably 500 pm or less, more preferably 400 pm or less, more preferably 300 pm or less, more preferably 250 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved. In a preferred embodiment, the weight average of the glass fibers GFT is 50 m or more, preferably 100 pm or more, more preferably 150 pm or more, more preferably 200 pm or more, more preferably 250 pm or more, more preferably 300 pm or more, more preferably 350 pm or more, more preferably 375 pm or more. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, the weight average of the glass fibers GFT is 3000 pm or less, preferably 2500 pm or less, more preferably 2000 pm or less, more preferably 1500 pm or less, more preferably 1000 pm or less, more preferably 500 pm or less, more preferably 450 pm or less, more preferably 400 pm or less, more preferably 375 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, the weight average of the glass fibers GF1 is 200 pm or more, preferably 300 pm or more, more preferably 400 pm or more, more preferably 500 pm or more, more preferably 550 pm or more, more preferably 600 pm or more, more preferably 700 pm or more, more preferably 800 pm or more, more preferably 900 pm or more, more preferably 1000 pm or more, more preferably 1100 pm or more, more preferably 1200 pm or more, more preferably 1300 pm or more, more preferably 1400 pm or more, more preferably 1500 pm or more. Thus, the mechanical properties of the polymer compound PC1 are improved.

The inventors recognized, that especially if the weight average of the glass fibers GF1 is long, preferably 550 pm or more, more preferably 600 pm or more, more preferably 700 pm or more, more preferably 800 pm or more, more preferably 900 pm or more, more preferably 1000 pm or more, more preferably 1100 pm or more, more preferably 1200 pm or more, more preferably 1300 pm or more, more preferably 1400 pm or more, more preferably 1500 pm or more, and the bulk density, preferably and the length of the glass fibers GF1, is/are as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, the weight average of the glass fibers GF1 is 3000 pm or less, preferably 2750 pm or less, more preferably 2500 pm or less, more preferably 2250 pm or less, more preferably 2000 pm or less, more preferably 1750 pm or less, more preferably 1600 pm or less. Thus, the mechanical properties of the polymer compound PC1 are improved.

In a preferred embodiment, dO.10i_ength of the glass fibers GF1 is 20 pm or more, preferably 30 pm or more, more preferably 40 pm or more, more preferably 50 pm or more, more preferably 70 pm or more, more preferably 100 pm or more, more preferably 110 pm or more, more preferably 120 pm or more, more preferably 130 pm or more, more preferably 150 pm or more, more preferably 170 pm or more, more preferably 180 pm or more, more preferably 190 pm or more, more preferably 200 pm or more, more preferably 210 pm or more. Especially if the value for dO.10i_ength of the glass fibers GF1 is high and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced. In a preferred embodiment, dO.10i_ength of the glass fibers GF1 is 350 m or less, preferably 300 m or less, more preferably 290 pm or less, more preferably 280 pm or less, more preferably 270 pm or less, more preferably 260 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 230 pm or less, more preferably 215 pm or less. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, dO.IOfrequency of the glass fibers GF1 is 20 pm or more, preferably 30 pm or more, more preferably 33 pm or more, more preferably 35 pm or more, more preferably 40 pm or more, more preferably 43 pm or more, more preferably 45 pm or more, more preferably 50 pm or more, more preferably 55 pm or more. Especially if the value for dO. 10f_requency of the glass fibers GF1 is high and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, dO.IOfrequency of the glass fibers GF1 is 100 pm or less, preferably 90 pm or less, more preferably 80 pm or less, more preferably 70 pm or less, more preferably 60 pm or less, more preferably 50 pm or less, more preferably 45 pm or less, more preferably 42 pm or less, more preferably 40 pm or less, more preferably 35 pm or less, more preferably 32 pm or less, more preferably 30 pm or less, more preferably 25 pm or less. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, dO.50i_ength of the glass fibers GF1 is 100 pm or more, preferably 250 pm or more, more preferably 500 pm or more, more preferably 600 pm or more, more preferably 700 pm or more, more preferably 800 pm or more, more preferably 900 pm or more, more preferably 1000 pm or more, more preferably 1100 pm or more. Especially if the value for dO. 50i_ength of the glass fibers GF1 is high and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, d0.50i_ength of the glass fibers GF1 is 3000 pm or less, preferably 2500 pm or less, more preferably 2000 pm or less, more preferably 1750 pm or less, more preferably 1500 pm or less, more preferably 1250 pm or less, more preferably 1150 pm or less. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, dO.SOfrequency of the glass fibers GF1 is 40 pm or more, preferably 50 pm or more, more preferably 60 pm or more, more preferably 100 pm or more, more preferably 150 pm or more, more preferably 180 pm or more, more preferably 190 pm or more, more preferably 200 pm or more, more preferably 220 pm or more, more preferably 250 pm or more. Especially if the value for dO. 50f_req_Uency of the glass fibers GF1 is high and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced. In a preferred embodiment, d0.50f_requency of the glass fibers GF1 is 500 m or less, preferably 300 pm or less, more preferably 260 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 150 pm or less, more preferably 100 pm or less, more preferably 60 pm or less. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, <100 pmi_ength of the glass fibers GF1 is 2.0 % or more, preferably 2.5 % or more, more preferably 3.0 % or more, more preferably 3.5 % or more, more preferably 4.0 % or more, more preferably 20.0 % or more, more preferably 30.0 % or more, more preferably 35.0 % or more. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, <100 pmi_ength of the glass fibers GF1 is 50.0 % or less, preferably 50 % or less, more preferably 40.0 % or less, more preferably 35.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less, more preferably 8.0 % or less, more preferably 7.0 % or less, more preferably 6.0 % or less, more preferably 5.5 % or less, more preferably 5.0 % or less, more preferably 4.5 % or less. Especially if the value for <100 miength of the glass fibers GF1 is low and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, <100 pimtrequency of the glass fibers GF1 is 10.0 % or more, preferably 20.0 % or more, more preferably 25.0 % or more, more preferably 30.0 % or more, more preferably 35.0 % or more. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, <100 pimtrequency of the glass fibers GF1 is 100.0 % or less, preferably 80 % or less, more preferably 70.0 % or less, more preferably 50.0 % or less, more preferably 45.0 % or less, more preferably 40.0 % or less, more preferably 38.0 % or less. Especially if the value for <100 imtrequency of the glass fibers GF1 is low and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, <200 pimi_ength of the glass fibers GF1 is 2.0 % or more, preferably 4.0 % or more, more preferably 6.0 % or more, more preferably 8.0 % or more, more preferably 9.0 % or more. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, <200 pimiength of the glass fibers GF1 is 100.0 % or less, preferably 75 % or less, more preferably 50.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less, more preferably 12.0 % or less. Especially if the value for <200 pimiength of the glass fibers GF1 is low and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced. In a preferred embodiment, <200 of the glass fibers GF1 is 30.0 % or more, preferably 40.0 % or more, more preferably 45.0 % or more, more preferably 47.0 % or more, more preferably 49.0 % or more, more preferably 50.0 % or more. Thus, the mechanical properties of the polymer compound PC1 are increased.

In a preferred embodiment, <200 imtrequency of the glass fibers GF1 is 100.0 % or less, preferably 85 % or less, more preferably 75.0 % or less, more preferably 65.0 % or less, more preferably 60.0 % or less, more preferably 55.0 % or less. Especially if the value for <200

of the glass fibers GF1 is low and the bulk density is as described herein, the mechanical properties of the polymer compound PC1 are increased and the susceptibility to failure of the method is reduced.

In a preferred embodiment, a ratio [pim/pim] of a/the length of the glass fibers GFT to a/the length of the glass fibers GF1 is 0.1 to 1 .0, preferably 0.2 to 0.9, more preferably 0.3 to 0.8, more preferably 0.4 to 0.7, more preferably 0.5 to 0.6. Thus, the mechanical properties of the polymer compound PC1 are increased.

A person skilled in the art understands that the length of glass fibers may change in a processing step, e.g. mixing or filtering. For this reason, a person skilled in the art understands that the length of the glass fibers GF1 is equal or longer than the length of the glass fibers GFT. Preferably, the length of glass fibers GF1 are longer than the length of glass fibers GFT and/or the length of glass fibers GFT' are longer than the length of glass fibers GFT

Further, the object described herein is at least partially solved by a method comprising the steps, preferably in this order: preferably milling, crushing and/or shredding, more preferably crushing and/or shredding, a polymer product PP2 comprising a polymer P2 and glass fibers GFT'; annealing a/the polymer product PP2 comprising a/the polymer P2 and glass fibers GFT', preferably wherein one or more, preferably all, of the following conditions is/are fulfilled: the temperature is at least once 250 °C or more and 1000 °C or less, preferably 320 °C or more and 800 °C or less, more preferably 350 °C or more and 800 °C or less, more preferably 450 °C or more and 600 °C or less; the annealing time is 0.1 h or more and 48 h or less, preferably 0.5 h or more and 24 h or less, more preferably 2 h or more and 6 h or less; and/or the annealing is performed in the presence of air, CO2, N2, Ar, or mixtures thereof, preferably air; preferably and cutting, chopping and/or filtering, preferably through a sieve, more preferably through a sieve of 10 mm (mesh size) or less, more preferably 8 mm or less, more preferably 6 mm or less, more preferably 5 mm or less, more preferably 3 mm or less, more preferably 2 mm or less, more preferably 1 mm or less, the glass fibers GFT' after annealing to obtain the glass fibers GF1 ; providing a mixture M1 comprising: a polymer P1, and glass fibers GF1 ; and mixing the mixture M1 to obtain a polymer compound PC1 comprising the polymer P1 and glass fibers GFT; preferably wherein the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more, preferably wherein the glass fibers GF1” are glass fiber roving and/or glass fiber textiles.

In a preferred embodiment, the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more.

In a preferred embodiment, the glass fibers GF1” are glass fiber roving and/or glass fiber textiles.

In a preferred embodiment, the one or more additive(s) comprise(s) glass fiber(s) vGF, preferably wherein the glass fiber(s) vGF are selected from bundled glass fiber(s), virgin glass fiber(s) and/or non-recycled glass fiber(s), preferably wherein a ratio (weight- %/weight-%) of a content of the glass fiber(s) vGF to a content of the glass fibers GF1 in the mixture M1 and/or a ratio (weight- %/weight-%) of a content of the glass fiber(s) vGF to a content of the glass fibers GFT in the polymer compound PC1 and/or polymer product PP1 is 0.01 to 100, preferably 0.1 to 10, more preferably 0.5 to 5, more preferably about 1.

Methods and Definitions: If not further specified, preferably the following methods are used, and definitions apply.

Tm and Tg were measured with DSC. DSC measurements were done according to DIN EN ISO 11357 using heat/cool Ing rate of 20K/min in a temperature range of 0 - 280°C on a Perkin Elmer DSC 8000.

The bulk density was measured as follows: A 250 mL measuring cylinder is filled with polymer pellet until reaching the 250 ml mark. The weight of the cylinder is measured empty and filled. The difference give the weight of a volume of 250 mL polymer pellet, this value is multiply by 4 to give the bulk density.

The dosability was evaluated as follows: The funnel of the extruder (Thermofischer; Haake) is filled with the necessary amount of fiber for the whole experiment. The selected throughput is 0,6 kg/h glass fiber to reach 2.0 kg/h polymer compound. This means 10 g glass fiber have to be metered in the extruder per minute. This target value is regularly measured weighting the fiber in the funnel after one minute metering. If this value differs from the target by more than 10 %, it was considered that the dosability is not given (-). If it differs from the target 10 % or less, it is given (+).

Organic content of the glass fibers GF1 : The organic content of the glass fibers GF1 was determined as follows: 5 mg glass fibers have been placed in the chamber of a TGA (thermogravimetric analysis) device (Q5000IR, TA instruments) and heated until 600°C at 10 °C/min. The weight loss in % during this heating corresponds to the organic content of the fiber.

The content of the glass fibers GF1 and/or GFT was determined as follows: 5 mg compound have been placed in the chamber of a TGA device (Q5000IR, TA instruments) and heated until 600°C at 10K/Min. The weight loss during this heating is the polymer content and/or organic additive content of the polymer compound. Content of glass fibers corresponds to 100 % - (weight loss in %).

Young's modulus, tensile strength and the elongation at break were measured according to ISO 527-1 at room temperature (=25°C).

The length of the glass fibers GF1 was measured as follows: 5 to 20 mg, preferably 10 mg glass fibers are dispersed in a mixture of 100 mL water and 2 drops of glycerin and transferred to a petri dish, which is placed on the surface of an Epson perfection V850 Pro flatbed scanner. Fibers shorter than 21 .2 pm cannot be detected due to the limited resolution of the scanner. Thus, fibers being shorter than 21 .2 pm are not considered.

Calculation of the value: length of the glass fibers GF1 (=arithmetic mean) = (Ltotai)/( f_requency); wherein Ltotai is the sum of the length (pm) of all fibers GF1 , and wherein Lfrequency is the sum of all fibers GF1 . average weight of glass fibers GF1 = (L_sqUare)/(Ltotai); wherein L_sqUare is the sum of the squares of the lengths (pm) of all fibers, and wherein Ltotai is the sum of the length (pm) of all fibers GF1 .

<100 piTIlength-

<100 piTIlength ^— (L 100 P ITI|ength)/(L|ength) , wherein L100pmi_ength is the sum of the length (pm) of all fibers GF1 being smaller than 100 pm, and wherein Length is the sum of the length (pm) of all fibers GF1 .

wherein L100pmfre_quency is the sum of all fibers GF1 being smaller than 100 pm, and wherein Lfrequency is the sum of all fibers GF1 .

<200 piTIlength.

<200 piTIlength ^— (L200piTI|ength)/(L|ength)₁ wherein L200pmi_ength is the sum of the length (pm) of all fibers GF1 being smaller than 200 pm, and wherein Length is the sum of the length (pm) of all fibers GF1 .

<200 piTlfrequency.

<200 piTlfrequency ^— (L200 piTlfrequency)/ (Lfrequency), wherein L200pmf_requency is the sum of all fibers GF1 being smaller than 200 pm, and wherein Lfrequency is the sum of all fibers GF1 . dO.10length ■ d0.10length — 0.1 X Llength, wherein Li_ength is the sum of the length (pm) of all fibers GF1 . d0.10frequency. d0.10frequency = maximum length of 10% of the smallest fibers GF1. dO.50 length. d0.50|ength ^— 0.5 X Llength, wherein Length is the sum of the length (pm) of all fibers GF1 . dO. 50frequency. d0.50freq_Uency = maximum length of 50% of the smallest fibers GF1 .

The length of the glass fibers GF1” was determined as follows:

First, the polymer compound comprising the glass fibers was pyrolyzed at 650°C for 1 .5 h to obtain the glass fibers. Then, a tip of a spatula (about 5 mg) glass fibers are dispersed in a mixture of 100 mL water and 2 drops of glycerin and transferred to a petri dish, which is placed on the surface of an Epson perfection V850 Pro flatbed scanner. This type of scanner is able to analyze the length of about 80 000 fibers at the same time. Fibers shorter than 21 .2 pm cannot be detected due to the limited resolution of the scanner. Thus, fibers being shorter than 21.2 pm are not considered.

Calculation of the value: length of the glass fibers GF1" (=arithmetic mean) = (Ltotai)/(Lf_requency); wherein Ltotai is the sum of the length (pm) of all fibers GF1 ", and wherein Lfrequency is the sum of all fibers GF1”.

The length of the glass fibers GFT was determined as follows:

First, the polymer compound comprising the glass fibers was pyrolyzed at 650°C for 1.5 h to obtain the glass fibers. Then, a tip of a spatula (about 5 mg) glass fibers are dispersed in a mixture of 100 mL water and 2 drops of glycerin and transferred to a petri dish, which is placed on the surface of an Epson perfection V850 Pro flatbed scanner. Fibers shorter than 21.2 pm cannot be detected due to the limited resolution of the scanner. Thus, fibers being shorter than 21.2 pm are not considered.

Calculation of the values: length of the glass fibers GFT (=arithmetic mean) = wherein Ltotai is the sum of the length (pm) of all fibers GFT, and wherein the sum of all fibers GFT. average weight of glass fibers GFT =

wherein L_sqUare is the sum of the squares of the lengths (pm) of all fibers, and wherein Ltotai is the sum of the length (pm) of all fibers GFT.

wherein L100pmi_ength is the sum of the length (pm) of all fibers GFT being smaller than 100 pm, and wherein is the sum of the length (pm) of all fibers GFT.

wherein L100pmfre_quency is the sum of all fibers GFT being smaller than 100 pm, and wherein the sum of all fibers GFT.

wherein L200pmi_ength is the sum of the length (pm) of all fibers GFT being smaller than 200 pm, and wherein is the sum of the length (pm) of all fibers GFT.

wherein L200 is the sum of all fibers GFT being smaller than 200 pm, and wherein the sum of all fibers GFT. 0.1 wherein is the sum of the length (pm) of all fibers GFT. d0.10frequency = maximum length of 10% of the smallest fibers GFT.

wherein is the sum of the length (pm) of all fibers GFT. dO. 50frequency. d0.50freq_Uency = maximum length of 50% of the smallest fibers GFT.

The organic content of the glass fibers was measured by TGA (Q5000IR, TA instruments) using heat/cooling rate of 20K/min in a temperature range of 0 - 600°C.

The BET was measured using inverse chromatography. For the measurements, the glass fibers were pyrolyzed at 650°C for 1 .5 h to get rid of the organic content. Then, 1 .5-2.2 g of the glass fibers were incorporated in the column of a chromatogram, Fisons Mega HRGC2 equipped with FID detector. This certified stainless chromatography column has a length of 100 mm and an inner diameter of 4 mm. This column is conditioned 16h at 30°C in a flow of dry Helium (12 mL/min), the same gas was used at 30°C and 20 mL/min as carrier. Measurements are carried out with octane at different pressures to obtain the BET value in m²/g. In addition, by using different solvents, the disperse surface energy in mJ/m² can be obtained.

The mixture M1 may comprise any other reinforcement, e.g. other glass fibers, carbon fibers, beads, stone powder, however, preferably the mixture M1 and thus also the polymer compound PC1 and the polymer product PP1 and/or PP2 do(es) not contain any further glass fibers, preferably any further fibers, more preferably any further reinforcement.

Even if some facts or effects are only explained for the method herein, they also apply for the polymer product PP1 and/or the polymer compound PC1 and vice versa, if not stated otherwise.

If not stated otherwise, normal conditions are used and/or applied, e.g., room temperature, preferably 25°C, and 1 bar, preferably 1013.25 mbar.

In summary, embodiments and preferred embodiments are listed below. The scope of protection is defined by the claims. The combination of two or more embodiments, e.g., 3, 4 or 8 embodiments is further preferred. Definitions and general statements herein preferably also apply for the following embodiments and preferred embodiments. Preferably, the steps described in the embodiments below are conducted, if present in the claims, in the order of the embodiments below.

1 . Method comprising the steps: providing a mixture M1 comprising: a polymer P1 , and glass fibers GF1 ; and mixing the mixture M1 to obtain a polymer compound PC1 comprising the polymer P1 and glass fibers GFT.

2. Method according to any one of the preceding embodiments, wherein the method comprises the step: converting the polymer compound PC1 to obtain a polymer product PP1. Polymer compound PC1 obtained by or obtainable by the method according to any one of the preceding embodiments. Polymer compound PC1 , preferably according to any one of the preceding embodiments, wherein the polymer compound PC1 comprises: a polymer P1 , and glass fibers GF1'. Polymer product PP1 comprising the polymer compound PC1 according to any one of the preceding embodiments. Use of glass fibers GF1 for the production of a polymer compound PC1 and/or polymer product PP1 , wherein the bulk density of the glass fibers GF1 is 0.7 g/cm³ or less, and/or wherein the length of the glass fibers GF1 is 30.0 mm or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed for 5 s or more, preferably 15 s or more, more preferably 20 s or more, more preferably 30 s or more, more preferably 50 s or more, more preferably 75 s or more, more preferably 100 s or more, more preferably 120 s or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed for 60 min or less, preferably 10 min or less, more preferably 5 min or less, more preferably 4 min or less, more preferably 180 s or less, more preferably 150 s or less, more preferably 120 s or less, more preferably 100 s or less, more preferably 80 s or less, more preferably 60 s or less, more preferably 40 s or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed by an extruder, preferably a twin-screw extruder. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a rotational speed of the extruder is 1 U/min or more, preferably 10 U/Min or more, more preferably 50 U/min or more, more preferably 100 U/min or more, more preferably 150 U/min or more, more preferably 200 U/min or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a rotational speed of the extruder is 500 U/min or less, preferably 400 U/Min or less, more preferably 350 U/min or less, more preferably 300 U/min or less, more preferably 250 U/min or less, more preferably 200 U/min or less.

12. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the flowrate, preferably in the extruder, is 10 g/h or more, preferably 50 g/h or more, more preferably 100 g/h or more, more preferably 500 g/h or more, more preferably 1000 g/h or more, more preferably 1500 g/h or more, more preferably 2000 g/h or more, more preferably 3000 g/h or more, more preferably 5000 g/h or more, more preferably 5000 kg/h or more, more preferably 10000 kg/h or more, more preferably 15000 kg/h or more.

13. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the flowrate, preferably in the extruder, is 20000 kg/h or less, preferably 15000 kg/h or less, more preferably 10000 kg/h or less, more preferably 5000 kg/h or less, more preferably 2500 kg/h or less, more preferably 20000 g/h or less, more preferably 10000 kg/h or less, more preferably 7500 kg/h or less, more preferably 5000 kg/h or less, more preferably 4000 kg/h or less, more preferably 3000 kg/h or less, more preferably 2500 kg/h or less, more preferably 2000 kg/h or less, more preferably 1500 kg/h or less, more preferably 1000 kg/h or less.

14. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed at Tm of polymer P1 or more, preferably (Tm of polymer P1 + 10 °C) or more, more preferably (Tm of polymer P1 + 20 °C) or more, more preferably (Tm of polymer P1 + 30 °C) or more, more preferably (Tm of polymer P1 + 40 °C) or more, more preferably (Tm of polymer P1 + 50 °C) or more.

15. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed at (Tm of polymer P1 + 100 °C) or less, preferably (Tm of polymer P1 + 90 °C) or less, more preferably (Tm of polymer P1 + 80 °C) or less, more preferably (Tm of polymer P1 + 70 °C) or less, more preferably (Tm of polymer P1 + 60 °C) or less, more preferably (Tm of polymer P1 + 50 °C) or less, more preferably (Tm of polymer P1 + 40 °C) or less, more preferably (Tm of polymer P1 + 30 °C) or less, more preferably (Tm of polymer P1 + 20 °C) or less, more preferably (Tm of polymer P1 + 10 °C) or less.

16. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed at 220 °C or more, preferably 230 °C or more, more preferably 240 °C or more, more preferably 250 °C or more, more preferably 260 °C or more, more preferably 270 °C or more, more preferably 280 °C or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the mixing is performed at 350 °C or less, preferably 300 °C or less, more preferably 290 °C or less, more preferably 270 °C or less, more preferably 260 °C or less, more preferably 250 °C or less, more preferably 240 °C or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are added to the polymer P1 in the extruder. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are added to the polymer P1 in the extruder within 1 kg/min or more, preferably 5 kg/min or more, more preferably 10 kg/min or more, more preferably 30 kg/min or more, more preferably 60 kg/min or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 were added to the polymer P1 in the extruder within 120 kg/min or less, more preferably 60 kg/min or less, more preferably 40 kg/min or less, more preferably 20 kg/min or less, more preferably 15 kg/min or less, more preferably 8 kg/min or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are recycled glass fibers, preferably recycled glass fiber yarns, rovings, recycled glass fiber textiles and/or fabrics, more preferably recycled glass fiber rovings and/or recycled glass fiber textiles. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a/the bulk density of the glass fibers GF1 is 0.05 g/cm³ or more, preferably 0.10 g/cm³ or more, more preferably 0.15 g/cm³ or more, more preferably 0.20 g/cm³ or more, more preferably 0.22 g/cm³ or more, more preferably 0.25 g/cm³ or more, more preferably 0.30 g/cm³ or more, more preferably 0.35 g/cm³ or more, more preferably 0.50 g/cm³ or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a/the bulk density of the glass fibers GF1 is 0.70 g/cm³ or less, preferably 0.60 g/cm³ or less, more preferably 0.50 g/cm³ or less, more preferably 0.40 g/cm³ or less, more preferably 0.30 g/cm³ or less, more preferably 0.25 g/cm³ or less, more preferably 0.20 g/cm³ or less, more preferably 0.15 g/cm³ or less, more preferably 0.10 g/cm³ or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a/the length of the glass fibers GF1 is 0.01 mm or more, preferably 0.05 mm or more, more preferably 0.1 mm or more, more preferably 0.10 mm or more, more preferably 0.15 mm or more, more preferably 0.2 mm or more, more preferably 0.20 mm or more, more preferably 0.25 mm or more, more preferably 0.3 mm or more, more preferably 0.30 mm or more, more preferably 0.35 mm or more, more preferably 0.4 mm or more, more preferably 0.40 mm or more, more preferably 0.45 mm or more, more preferably 0.5 mm or more, more preferably 0.6 mm or more, more preferably 0.7 mm or more, more preferably 0.8 mm or more, more preferably 0.9 mm or more, more preferably 1.0 mm or more, more preferably 1.5 mm or more, more preferably 2.5 mm or more, more preferably 5.0 mm or more, more preferably 7.5 mm or more, more preferably 10.0 mm or more, more preferably 15.0 mm or more.

25. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a/the length of the glass fibers GF1 is 30.0 mm or less, preferably 25.0 mm or less, more preferably 20.0 mm or less, more preferably 17.5 mm or less, more preferably 15.0 mm or less, more preferably 12.5 mm or less, more preferably 10.0 mm or less, more preferably 7.5 mm or less, more preferably 5.0 mm or less, more preferably 4.0 mm or less, more preferably 3.9 mm or less, more preferably 3.5 mm or less, more preferably 3.0 mm or less, more preferably 2.0 mm or less, more preferably 1.0 mm or less, more preferably 0.9 mm or less, more preferably 0.8 mm or less, more preferably 0.7 mm or less, more preferably 0.6 mm or less, more preferably 0.5 mm or less, more preferably 0.4 mm or less, more preferably 0.3 mm or less, more preferably 0.2 mm or less, more preferably 0.1 mm or less.

26. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein an orientation of the glass fibers GF1 is predominantly isotropic, preferably isotopic.

27. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the shape of the glass fibers GF1 is wool-like.

28. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are obtainable or obtained from a polymer product PP2 comprising a polymer P2 and glass fibers GF1”, preferably wherein a length of the glass fibers GF1” is 30 mm or more, preferably 100 mm or more and/or wherein the glass fibers GF1” are glass-fiber textiles.

29. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are obtained or obtainable by a method comprising the following step(s): preferably milling, crushing and/or shredding, more preferably crushing and/or shredding, a/the polymer product PP2 comprising a polymer P2 and glass fibers GF1”, preferably wherein the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more, annealing a/the polymer product PP2 comprising a/the polymer P2 and glass fibers GF1 ”, preferably wherein one or more, preferably all, of the following conditions is/are fulfilled: the temperature is at least once 250 °C or more and 1000 °C or less, preferably 320 °C or more and 800 °C or less, more preferably 350 °C or more and 800 °C or less, more preferably 450 °C or more and 600 °C or less; the annealing time is 0.1 h or more and 48 h or less, preferably 0.5 h or more and 24 h or less, more preferably 2 h or more and 6 h or less; and/or the annealing is performed in the presence of air, CO2, N2, Ar, or mixtures thereof, preferably air; and preferably and cutting, chopping and/or filtering, preferably through a sieve, more preferably through a sieve of 10 mm (mesh size) or less, more preferably 8 mm or less, more preferably 6 mm or less, more preferably 5 mm or less, more preferably 3 mm or less, more preferably 2 mm or less, more preferably 1 mm or less, the glass fibers GF1” after annealing to obtain the glass fibers GF1 ; preferably and wherein the glass fibers GF1” are glass fiber roving and/or glass fiber textiles. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein an age of the polymer product PP2 is 1 year or more, preferably 5 years or more, more preferably 10 years or more, more preferably 20 years or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are etched and/or corroded. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a BET value [m²/g] and/or a disperse surface energy [mJ/m²] of glass fibers GF1 and glass fiber GFT; and/or glass fibers GF1 and glass fiber GF1”; and/or glass fibers GFT and glass fiber GF1” are not the same. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are uncoated. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein an organic content of the glass fibers GF1 is 1 weight-% or less, preferably 0.9 weight-% or less, more preferably 0.8 weight-% or less, more preferably 0.7 weight-% or less, more preferably 0.6 weight-% or less, more preferably 0.5 weight-% or less, more preferably 0.4 weight-% or less, more preferably 0.3 weight-% or less, more preferably 0.2 weight-% or less, more preferably 0.1 weight-% or less, more preferably 0.05 weight-% or less, more preferably 0.03 weight-% or less, more preferably 0.01 weight-% or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1 are recycled glass fibers. 36. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.10i_ength of the glass fibers GFT is 20 pm or more, preferably 30 m or more, more preferably 40 pm or more, more preferably 50 pm or more, more preferably 70 pm or more, more preferably 100 pm or more, more preferably 110 pm or more, more preferably 120 pm or more, more preferably 130 pm or more, more preferably 150 pm or more, more preferably 170 pm or more, more preferably 180 pm or more.

37. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.10i_ength of the glass fibers GFT is 250 pm or less, preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 160 pm or less, more preferably 140 pm or less, more preferably 130 pm or less, more preferably 120 pm or less, more preferably 110 pm or less, more preferably 100 pm or less, more preferably 75 pm or less, more preferably 50 pm or less.

38. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.IOfrequency of the glass fibers GFT is 20 pm or more, preferably 30 pm or more, more preferably 33 pm or more, more preferably 35 pm or more, more preferably 40 pm or more, more preferably 43 pm or more, more preferably 45 pm or more, more preferably 50 pm or more, more preferably 55 pm or more.

39. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.IOfrequency of the glass fibers GFT is 100 pm or less, preferably 90 pm or less, more preferably 80 pm or less, more preferably 70 pm or less, more preferably 60 pm or less, more preferably 50 pm or less, more preferably 45 pm or less, more preferably 42 pm or less, more preferably 40 pm or less, more preferably 35 pm or less, more preferably 32 pm or less, more preferably 30 pm or less, more preferably 25 pm or less.

40. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein d0.50i_ength of the glass fibers GFT is 150 pm or more, preferably 160 pm or more, more preferably 200 pm or more, more preferably 250 pm or more, more preferably 260 pm or more, more preferably 300 pm or more, more preferably 350 pm or more, more preferably 370 pm or more, more preferably 400 pm or more, more preferably 450 pm or more.

41. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein d0.50i_ength of the glass fibers GFT is 800 pm or less, preferably 500 pm or less, more preferably 470 pm or less, more preferably 460 pm or less, more preferably 400 pm or less, more preferably 360 pm or less, more preferably 350 pm or less, more preferably 300 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 180 pm or less. 42. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.SOfrequency of the glass fibers GFT is 40 pirn or more, preferably 50 m or more, more preferably 60 pm or more, more preferably 100 pm or more, more preferably 150 pm or more, more preferably 180 pm or more, more preferably 190 pm or more, more preferably 200 pm or more, more preferably 220 pm or more, more preferably 250 pm or more.

43. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.SOtrequency of the glass fibers GFT is 500 pm or less, preferably 300 pm or less, more preferably 260 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 150 pm or less, more preferably 100 pm or less, more preferably 60 pm or less.

44. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100 pmi_ength of the glass fibers GFT is 5.0 % or more, preferably 5.5 % or more, more preferably 6.0 % or more, more preferably 6.5 % or more, more preferably 7.0 % or more, more preferably 7.5 % or more, more preferably 10.0 % or more, more preferably 20.0 % or more, more preferably 30.0 % or more, more preferably 35.0 % or more.

45. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100 pmi_ength of the glass fibers GFT is 50.0 % or less, preferably 50 % or less, more preferably 40.0 % or less, more preferably 35.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less, more preferably 8.0 % or less, more preferably 7.0 % or less, more preferably 6.0 % or less, more preferably 5.5 % or less.

46. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100

of the glass fibers GFT is 15.0 % or more, preferably 20.0 % or more, more preferably 25.0 % or more, more preferably 29.0 % or more, more preferably 30.0 % or more, more preferably 31.0 % or more, more preferably 35.0 % or more, more preferably 40.0 % or more, more preferably 60.0 % or more, more preferably 70.0 % or more.

47. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100

of the glass fibers GFT is 100.0 % or less, preferably 80 % or less, more preferably 70.0 % or less, more preferably 50.0 % or less, more preferably 35.0 % or less, more preferably 31 .0 % or less, more preferably 30.0 % or less, more preferably 29.0 % or less.

48. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200 imi_ength of the glass fibers GFT is 10.0 % or more, preferably 12.0 % or more, more preferably 15.0 % or more, more preferably 20.0 % or more, more preferably 30.0 % or more, more preferably 50.0 % or more, more preferably 55.0 % or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200 pimi_ength of the glass fibers GFT is 100.0 % or less, preferably 75 % or less, more preferably 60.0 % or less, more preferably 55.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein

of the glass fibers GFT is 40.0 % or more, preferably 45.0 % or more, more preferably 50.0 % or more, more preferably 60.0 % or more, more preferably 70.0 % or more, more preferably 80.0 % or more, more preferably 85.0 % or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200

of the glass fibers GFT is 100.0 % or less, preferably 85 % or less, more preferably 60.0 % or less, more preferably 55.0 % or less, more preferably 50.0 % or less, more preferably 45.0 % or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein polymer P1 is a thermoplastic polymer. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein polymer P1 and/or P2 is and/or polymer product PP1 and/or PP2 comprises polyamide (PA); preferably PA 6 or PA 66; polyisocyanate polyaddition product; preferably polyurethane (PU), thermoplastic polyurethane (TPU), polyurea or polyisocyanurate (PIR); low-density polyethylene (LDPE), high-density polyethylene (HDPE), polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl acetate (PVA), polystyrene (PS), poly acrylonitrile butadiene styrene (ABS), poly styrene acrylonitrile (SAN), poly acrylate styrene acrylonitrile (ASA), polytetrafluoroethylene (PTFE), poly(methyl acrylate) (PMA), poly(methyl methacrylate) (PMMA), polybutadiene (BR, PBD), poly(cis-1 ,4-isoprene), poly(trans-1 ,4-isoprene), polyoxymethylene (POM), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polybutylene adipate coterephthalate (PBAT), polyester (PES), polyether sulfone (PESU), polyhydroxyalkanoate (PHA), poly-3-hydroxybutyrate (P3HB), poly-4-hydroxybutyrate (P4HB), polyhydroxyvalerate (PHV), polyhydroxyhexanoate (PHH), polyhydroxyoctanoate (PHO), polylactic acid (PLA), polysulfone (PSU), polyphenylene sulfone (PPSU), polycarbonate (PC), polyether ether ketone (PEEK), poly(p-phenylene oxide) (PPO), poly(p-phenylene ether) (PPE); or copolymer or mixture thereof, preferably polyamide (PA); preferably PA 6 or PA 66 or mixtures thereof. 54. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a content of the glass fiber GF1 and/or GF1' in the mixture M1 , polymer compound PC1 or polymer product PP1 is 1 weight-% or more, preferably 2 weight-% or more, more preferably 3 weight-% or more, more preferably 4 weight-% or more, more preferably 5 weight-% or more, more preferably 10 weight-% or more, more preferably 15 weight-% or more, more preferably 20 weight-% or more, more preferably 21 weight-% or more, more preferably 25 weight-% or more, more preferably 30 weight-% or more, more preferably 35 weight-% or more, more preferably 40 weight-% or more, more preferably 45 weight-% or more.

55. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a content of the glass fiber GF1 and/or GF1' in the mixture M1 , polymer compound PC1 or polymer product PP1 is 50 weight-% or less, preferably 45 weight-% or less, more preferably 40 weight-% or less, more preferably 35 weight-% or less, more preferably 30 weight-% or less, more preferably 25 weight-% or less, more preferably 20 weight-% or less, more preferably 15 weight-% or less, more preferably 10 weight-% or less, more preferably 5 weight-% or less.

56. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a content of the polymer P1 in the mixture M1 , polymer compound PC1 or polymer product PP1 is 1 weight-% or more, preferably 2 weight-% or more, more preferably 3 weight-% or more, more preferably 4 weight-% or more, more preferably 5 weight-% or more, more preferably 10 weight-% or more, more preferably 15 weight-% or more, more preferably 20 weight-% or more, more preferably 25 weight-% or more, more preferably 30 weight-% or more, more preferably 35 weight-% or more, more preferably 40 weight-% or more, more preferably 45 weight-% or more.

57. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a content of polymer P1 in the mixture M1 , polymer compound PC1 or polymer product PP1 is 99 weight-% or less, preferably 95 weight-% or less, more preferably 90 weight-% or less, more preferably 85 weight-% or less, more preferably 80 weight-% or less, more preferably 75 weight-% or less, more preferably 50 weight-% or less, more preferably 35 weight-% or less.

58. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein polymer P1 is at least partially recycled and/or biobased.

59. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the content of the polymer(s) and/or the glass fibers and/or the one or more additive(s) is/are determined based on identity preservation and/or segregation and/or mass balance and/or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard. 60. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the polymer compound PC1 or polymer product PP1 comprises one or more additive(s).

61. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the one or more additive(s) is/are selected from fiber(s), antioxidating agent(s), stabilizer(s), lubricant(s), mineral(s), colorant(s), pigment(s), dye(s), soot, talc, carbon black, bio additive(s), plasticizer(s), flame retardant(s), and mixtures thereof.

62. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the polymer compound PC1 and/or the polymer product PP1 comprises, preferably consist of, polymer P1 , glass fibers GF1' and one or more additive(s).

63. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the polymer compound PC1 and/or the polymer product PP1 and/or PP2 is/are or is/are a part of: a part of a car; preferably cylinder head cover, engine cover, housing for charge air cooler, charge air cooler flap, intake pipe, intake manifold, connector, gear wheel, fan wheel, cooling water box, housing, housing part for heat exchanger, coolant cooler, charge air cooler, thermostat, water pump, radiator, fastening part, part of battery system for electromobility, dashboard, steering column switch, seat, headrest, center console, transmission component, door module, A, B, C or D pillar cover, spoiler, door handle, exterior mirror, windscreen wiper, windscreen wiper protection housing, decorative grill, cover strip, roof rail, window frame, sunroof frame, antenna panel, headlight and taillight, engine cover, cylinder head cover, intake manifold, airbag, cushion, or coating; a cloth; preferably shirt, trousers, pullover, boot, shoe, shoe sole, tight or jacket; an electrical part; preferably electrical or electronic passive or active component, circuit board, printed circuit board, housing component, foil, line, switch, plug, socket, distributor, relay, resistor, capacitor, inductor, bobbin, lamp, diode, LED, transistor, connector, regulator, integrated circuit (IC), processor, controller, memory, sensor, microswitch, microbutton, semiconductor, reflector housing for lightemitting diodes (LED), fastener for electrical or electronic component, spacer, bolt, strip, slide-in guide, screw, nut, film hinge, snap hook (snap-in), or spring tongue; a consumer, agricultural product or pharmaceutical product; preferably tennis string, climbing rope, bristle, brush, artificial grass, 3D printing filament, grass trimmer, zipper, hook and loop fastener, paper machine clothing, extrusion coating, fishing line, fishing net, offshore line and rope, vial, syringe, ampoule, bottle, sliding element, spindle nut, chain conveyor, plain bearing, roller, wheel, gear, roller, ring gear, screw and spring dampers, hose, pipeline, cable sheathing, socket, switch, cable tie, fan wheel, carpet, box or bottle for cosmetics, mattress, cushion, insulation, detergent, dishwasher tabs or powder, shampoo, body wash, shower gel, soap, fertilizer, fungicide, or pesticide; a packaging for the food industry; preferably mono- or multi-layer blown film, cast film (mono- or multi-layer), biaxially stretched film, or laminating film; or a part of a construction; preferably a rotor blade, insulating material, frame, housing, wall, coating, or separating wall. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a Young's modulus of the polymer compound PC1 and/or polymer product PP1 is/are 6.00*10^A3 MPa or more, preferably 6.10*10^A3 MPa or more, more preferably 6.20*10^A3 MPa or more, more preferably 6.30*10^A3 MPa or more, more preferably 6.40*10^A3 MPa or more, more preferably 6.50*10^A3 MPa or more, more preferably 7.00*10^A3 MPa or more, more preferably 7.50*10^A3 MPa or more, more preferably 8.00*10^A3 MPa or more, more preferably 8.50*10^A3 MPa or more, more preferably 8.90*10^A3 MPa or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a Young's modulus of the polymer compound PC1 and/or polymer product PP1 is/are 3.00*10^A4 MPa or less, preferably 2.50*10^A4 MPa or less, more preferably 2.00*10^A4 MPa or less, more preferably 1.50*10^A4 MPa or less, more preferably 1.00*10^A4 MPa or less, more preferably 9.50*10^A3 MPa or less, more preferably 9.00*10^A4 MPa or less, more preferably 8.00*10^A4 MPa or less, more preferably 7.00*10^A4 MPa or less, more preferably 6.50*10^A4 MPa or less, more preferably 6.20*10^A4 MPa or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a tensile strength of the polymer compound PC1 and/or polymer product PP1 is 90 MPa or more, preferably 95 MPa or more, more preferably 100 MPa or more, more preferably 110 MPa or more, more preferably 120 MPa or more, more preferably 130 MPa or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a tensile strength of the polymer compound PC1 and/or polymer product PP1 is 200 MPa or less, preferably 180 MPa or less, more preferably 160 MPa or less, more preferably 140 MPa or less, more preferably 130 MPa or less, more preferably 125 MPa or less, more preferably 120 MPa or less, more preferably 115 MPa or less, more preferably 110 MPa or less. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein an elongation at break at room temperature of the polymer compound PC1 and/or polymer product PP1 is 2.0 % or more, preferably 2.5 % or more, more preferably 2.8 % or more, more preferably 3.0 % or more, more preferably 3.2 % or more, more preferably 3.5 % or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein an elongation at break at room temperature of the polymer compound PC1 and/or polymer product PP1 is 5.0 % or less, preferably 4.0 % or less, more preferably 3.5 % or less, more preferably 3.3 % or less, more preferably 3.1 % or less, more preferably 2.9 % or less, more preferably 2.7 % or less.

70. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the method can be performed fast, is reproducible, and/or, preferably and, is less susceptible to failure, preferably is reproducible, and/or is less susceptible to failure.

71. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the polymer compound PC1 and/or the polymer product PP1 exhibits a predefined amount of recycled glass fibers GFT, a high amount of recycled glass fibers GFT, a specific length of recycled glass fibers GFT, improved mechanical properties, and/or, preferably and, improved sustainability, preferably a predefined amount of recycled glass fibers GFT, a high amount of recycled glass fibers GFT, and/or a specific length of recycled glass fibers GFT.

72. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the length of the glass fibers GFT is 100 pm or more, preferably 150 pm or more, more preferably 175 pm or more, more preferably 200 pm or more, more preferably 230 pm or more.

73. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the length of the glass fibers GFT is 1000 pm or less, preferably 900 pm or less, more preferably 800 pm or less, more preferably 700 pm or less, more preferably 600 pm or less, more preferably 500 pm or less, more preferably 400 pm or less, more preferably 300 pm or less, more preferably 250 pm or less.

74. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the weight average of the glass fibers GFT is 50 pm or more, preferably 100 pm or more, more preferably 150 pm or more, more preferably 200 pm or more, more preferably 250 pm or more, more preferably 300 pm or more, more preferably 350 pm or more, more preferably 375 pm or more.

75. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the weight average of the glass fibers GFT is 3000 pm or less, preferably 2500 pm or less, more preferably 2000 pm or less, more preferably 1500 pm or less, more preferably 1000 pm or less, more preferably 500 pm or less, more preferably 450 pm or less, more preferably 400 pm or less, more preferably 375 pm or less.

76. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the weight average of the glass fibers GF1 is 200 pm or more, preferably 300 pm or more, more preferably 400 m or more, more preferably 500 pm or more, more preferably 550 pm or more, more preferably 600 pm or more, more preferably 700 pm or more, more preferably 800 pm or more, more preferably 900 pm or more, more preferably 1000 pm or more, more preferably 1100 pm or more, more preferably 1200 pm or more, more preferably 1300 pm or more, more preferably 1400 pm or more, more preferably 1500 pm or more.

77. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the weight average of the glass fibers GF1 is 3000 pm or less, preferably 2750 pm or less, more preferably 2500 pm or less, more preferably 2250 pm or less, more preferably 2000 pm or less, more preferably 1750 pm or less, more preferably 1600 pm or less.

78. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.10i_ength of the glass fibers GF1 is 20 pm or more, preferably 30 pm or more, more preferably 40 pm or more, more preferably 50 pm or more, more preferably 70 pm or more, more preferably 100 pm or more, more preferably 110 pm or more, more preferably 120 pm or more, more preferably 130 pm or more, more preferably 150 pm or more, more preferably 170 pm or more, more preferably 180 pm or more, more preferably 190 pm or more, more preferably 200 pm or more, more preferably 210 pm or more.

79. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.10i_ength of the glass fibers GF1 is 350 pm or less, preferably 300 pm or less, more preferably 290 pm or less, more preferably 280 pm or less, more preferably 270 pm or less, more preferably 260 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 230 pm or less, more preferably 215 pm or less.

80. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.IOfrequency of the glass fibers GF1 is 20 pm or more, preferably 30 pm or more, more preferably 33 pm or more, more preferably 35 pm or more, more preferably 40 pm or more, more preferably 43 pm or more, more preferably 45 pm or more, more preferably 50 pm or more, more preferably 55 pm or more.

81. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.IOfrequency of the glass fibers GF1 is 100 pm or less, preferably 90 pm or less, more preferably 80 pm or less, more preferably 70 pm or less, more preferably 60 pm or less, more preferably 50 pm or less, more preferably 45 pm or less, more preferably 42 pm or less, more preferably 40 pm or less, more preferably 35 pm or less, more preferably 32 pm or less, more preferably 30 pm or less, more preferably 25 pm or less. 82. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein d0.50i_ength of the glass fibers GF1 is 100 pm or more, preferably 250 pm or more, more preferably 500 pm or more, more preferably 600 pm or more, more preferably 700 pm or more, more preferably 800 pm or more, more preferably 900 pm or more, more preferably 1000 pm or more, more preferably 1100 pm or more.

83. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein d0.50i_ength of the glass fibers GF1 is 3000 pm or less, preferably 2500 pm or less, more preferably 2000 pm or less, more preferably 1750 pm or less, more preferably 1500 pm or less, more preferably 1250 pm or less, more preferably 1150 pm or less.

84. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.SOfrequency of the glass fibers GF1 is 40 pm or more, preferably 50 pm or more, more preferably 60 pm or more, more preferably 100 pm or more, more preferably 150 pm or more, more preferably 180 pm or more, more preferably 190 pm or more, more preferably 200 pm or more, more preferably 220 pm or more, more preferably 250 pm or more.

85. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein dO.SOfrequency of the glass fibers GF1 is 500 pm or less, preferably 300 pm or less, more preferably 260 pm or less, more preferably 250 pm or less, more preferably 240 pm or less, more preferably 200 pm or less, more preferably 190 pm or less, more preferably 180 pm or less, more preferably 170 pm or less, more preferably 150 pm or less, more preferably 100 pm or less, more preferably 60 pm or less.

86. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100 pmi_ength of the glass fibers GF1 is 2.0 % or more, preferably 2.5 % or more, more preferably 3.0 % or more, more preferably 3.5 % or more, more preferably 4.0 % or more, more preferably 20.0 % or more, more preferably 30.0 % or more, more preferably 35.0 % or more.

87. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100 pmiength of the glass fibers GF1 is 50.0 % or less, preferably 50 % or less, more preferably 40.0 % or less, more preferably 35.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less, more preferably 8.0 % or less, more preferably 7.0 % or less, more preferably 6.0 % or less, more preferably 5.5 % or less, more preferably 5.0 % or less, more preferably 4.5 % or less.

88. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100 pm^quency of the glass fibers GF1 is 10.0 % or more, preferably 20.0 % or more, more preferably 25.0 % or more, more preferably 30.0 % or more, more preferably 35.0 % or more. 89. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <100 pimtrequency of the glass fibers GF1 is 100.0 % or less, preferably 80 % or less, more preferably 70.0 % or less, more preferably 50.0 % or less, more preferably 45.0 % or less, more preferably 40.0 % or less, more preferably 38.0 % or less.

90. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200 imi_ength of the glass fibers GF1 is 2.0 % or more, preferably 4.0 % or more, more preferably 6.0 % or more, more preferably 8.0 % or more, more preferably 9.0 % or more.

91. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200 imi_ength of the glass fibers GF1 is 100.0 % or less, preferably 75 % or less, more preferably 50.0 % or less, more preferably 25.0 % or less, more preferably 15.0 % or less, more preferably 12.0 % or less.

92. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200 pimtrequency of the glass fibers GF1 is 30.0 % or more, preferably 40.0 % or more, more preferably 45.0 % or more, more preferably 47.0 % or more, more preferably 49.0 % or more, more preferably 50.0 % or more.

93. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein <200 imtrequency of the glass fibers GF1 is 100.0 % or less, preferably 85 % or less, more preferably 75.0 % or less, more preferably 65.0 % or less, more preferably 60.0 % or less, more preferably 55.0 % or less.

94. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein a ratio [pim/pim] of a/the length of the glass fibers GF1 ' to a/the length of the glass fibers GF1 is 0.1 to 1.0, preferably 0.2 to 0.9, more preferably 0.3 to 0.8, more preferably 0.4 to 0.7, more preferably 0.5 to 0.6.

95. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the length of glass fibers GF1 are longer than the length of glass fibers GFT.

96. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the length of glass fibers GF1” are longer than the length of glass fibers GF1.

97. Method, polymer compound PC1 , polymer product PP1 or use, preferably according to any one of the preceding embodiments, comprising the steps, preferably in this order: preferably milling, crushing and/or shredding, more preferably crushing and/or shredding, a polymer product PP2 comprising a polymer P2 and glass fibers GF1”; annealing a/the polymer product PP2 comprising a/the polymer P2 and glass fibers GF1 ”, preferably wherein one or more, preferably all, of the following conditions is/are fulfilled: the temperature is at least once 250 °C or more and 1000 °C or less, preferably 320 °C or more and 800 °C or less, more preferably 350 °C or more and 800 °C or less, more preferably 450 °C or more and 600 °C or less; the annealing time is 0.1 h or more and 48 h or less, preferably 0.5 h or more and 24 h or less, more preferably 2 h or more and 6 h or less; and/or the annealing is performed in the presence of air, CO2, N2, Ar, or mixtures thereof, preferably air; preferably and cutting, chopping and/or filtering, preferably through a sieve, more preferably through a sieve of 10 mm (mesh size) or less, more preferably 8 mm or less, more preferably 6 mm or less, more preferably 5 mm or less, more preferably 3 mm or less, more preferably 2 mm or less, more preferably 1 mm or less, the glass fibers GF1” after annealing to obtain the glass fibers GF1 ; providing a mixture M1 comprising: a polymer P1, and glass fibers GF1 ; and mixing the mixture M1 to obtain a polymer compound PC1 comprising the polymer P1 and glass fibers GFT; preferably wherein the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more, preferably wherein the glass fibers GF1” are glass fiber roving and/or glass fiber textiles. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the glass fibers GF1” are glass fiber roving and/or glass fiber textiles. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding embodiments, wherein the one or more additive(s) comprise(s) glass fiber(s) vGF, preferably wherein the glass fiber(s) vGF are selected from bundled glass fiber(s), virgin glass fiber(s) and/or non-recycled glass fiber(s), preferably wherein a ratio (weight- %/weight-%) of a content of the glass fiber(s) vGF to a content of the glass fibers GF1 in the mixture M1 and/or a ratio (weight-%/weight-%) of a content of the glass fiber(s) vGF to a content of the glass fibers GFT in the polymer compound PC1 and/or polymer product PP1 is 0.01 to 100, preferably 0.1 to 10, more preferably 0.5 to 5, more preferably about 1. Examples

The invention is further illustrated by the following examples.

Synthesis of glass fibers GF1

The glass fibers GF1 were obtained according to the following method: A polymer compound derived from a rotor blade comprising glass fiber textiles was shredded using a machine Hammermuhle L04 from the company Eriez. The shredded composite was pyrolyzed using an oven Nabertherm from the company Fischer Scientific for 4h at 500°C in the presence of air. These glass fibers were used as they are (B2) or grinded and sieved using a grinder C17.26sv from the company Wanner equipped with a sieve of 1 mm (for B3) or 5 mm (for B4).

Synthesis of the polymer compounds:

The following components were used:

Polymer:

A1 Polyamide 6 (PA6, Ultramid® B27E; BASF SE)

Glass Fibers:

B1 commercial chopped glass fibers DS1110 from the company 3B

B2 recycled glass fibers (see above)

B3 recycled glass fibers, filtered using a 1 mm sieve (see above)

B4 recycled glass fibers, filtered using a 5 mm sieve (see above)

Table 1 : Composition of examples

Al Bl B2 B3 B4

Example 1 weight-% 70 30

Example 2 weight-% 70 30

Example 3 weight-% 70 30

Example 4 weight-% 70 30

The components listed in Table 1 were mixed with a twin screw extruder (Thermofischer; Haake); at 100 rpm with a barrel temperature of 260°C and a throughput of 2.0 kg/h) and then granulated. Test specimens were formed of the granulate by injection molding using an injection molding machine (Xplore) and analyzed. In the measurements, the following values were obtained: Example # Example 1 Example 2 Example 3 Example 4 unit

GF1 Fiber length mm 4.0* >20^# 0.1-0.2§ 0.46'

GF1 Bulk density g/cm³ 0.80 0.10 0.30 0.22

GF1 Weight average pm 1519

Claims

1 . Method comprising the steps: providing a mixture M1 comprising: a polymer P1, and glass fibers GF1 ; and mixing the mixture M1 to obtain a polymer compound PC1 comprising the polymer P1 and glass fibers GF1', wherein a bulk density of the glass fibers GF1 is 0.70 g/cm³ or less, and/or wherein a length of the glass fibers GF1 is 3.9 mm or less.

2. Method according to claim 1, wherein the method comprises the step: converting the polymer compound PC1 to obtain a polymer product PP1 .

3. Polymer compound PC1 , preferably obtained by or obtainable by the method according to claim 1 , wherein the polymer compound PC1 comprises: a polymer P1 , and glass fibers GF1'.

4. Polymer product PP1 comprising the polymer compound PC1 according to claim 3.

5. Use of glass fibers GF1 for the production of a polymer compound PC1 and/or polymer product PP1 , wherein a bulk density of the glass fibers GF1 is 0.70 g/cm³ or less, and/or wherein a length of the glass fibers GF1 is 3.9 mm or less.

6. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding claims, wherein the glass fibers GF1 are recycled glass fibers, preferably recycled glass fiber rovings and/or recycled glass fiber textiles.

7. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding claims, wherein a/the bulk density of the glass fibers GF1 is 0.05 g/cm³ or more, preferably 0.10 g/cm³ or more, more preferably 0.15 g/cm³ or more, more preferably 0.20 g/cm³ or more, more preferably 0.22 g/cm³ or more, more preferably 0.25 g/cm³ or more, more preferably 0.30 g/cm³ or more, more preferably 0.35 g/cm³ or more, more preferably 0.50 g/cm³ or more; and/or wherein a/the bulk density of the glass fibers GF1 is 0.70 g/cm³ or less, preferably 0.60 g/cm³ or less, more preferably 0.50 g/cm³ or less, more preferably 0.40 g/cm³ or less, more preferably 0.30 g/cm³ or less, more preferably 0.25 g/cm³ or less, more preferably 0.20 g/cm³ or less, more preferably 0.15 g/cm³ or less, more preferably 0.10 g/cm³ or less.

8. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding claims, wherein a/the length of the glass fibers GF1 is 0.01 mm or more, preferably 0.05 mm or more, more preferably 0.1 mm or more, more preferably 0.2 mm or more, more preferably 0.3 mm or more, more preferably 0.4 mm or more, more preferably 0.5 mm or more, more preferably 0.6 mm or more, more preferably 0.7 mm or more, more preferably 0.8 mm or more, more preferably 0.9 mm or more, more preferably 1.0 mm or more, more preferably 1.5 mm or more, more preferably 2.5 mm or more, more preferably 5.0 mm or more, more preferably 7.5 mm or more, more preferably 10.0 mm or more, more preferably 15.0 mm or more; and/or wherein a/the length of the glass fibers GF1 is 30.0 mm or less, preferably 25.0 mm or less, more preferably 20.0 mm or less, more preferably 17.5 mm or less, more preferably 15.0 mm or less, more preferably 12.5 mm or less, more preferably 10.0 mm or less, more preferably 7.5 mm or less, more preferably 5.0 mm or less, more preferably 4.0 mm or less, more preferably 3.9 mm or less, more preferably 3.5 mm or less, more preferably 3.0 mm or less, more preferably 2.0 mm or less, more preferably 1 .0 mm or less, more preferably 0.9 mm or less, more preferably 0.8 mm or less, more preferably 0.7 mm or less, more preferably 0.6 mm or less, more preferably 0.5 mm or less, more preferably 0.4 mm or less, more preferably 0.3 mm or less, more preferably 0.2 mm or less, more preferably 0.1 mm or less.

9. Method, polymer compound PC1 , polymer product PP1 or use according to any one of the preceding claims, wherein the shape of the glass fibers GF1 is wool-like.

10. Method, polymer compound PC1, polymer product PP1 or use according to any one of the preceding claims, wherein the glass fibers GF1 are obtainable or obtained from a polymer product PP2 comprising a polymer P2 and glass fibers GF1”, preferably wherein a length of the glass fibers GF1” is 30 mm or more, preferably 100 mm or more and/or wherein the glass fibers GF1” are glass-fiber textiles; and/or wherein the glass fibers GF1 are obtained or obtainable by a method comprising the following step(s): preferably milling, crushing and/or shredding, more preferably crushing and/or shredding, a/the polymer product PP2 comprising a polymer P2 and glass fibers GF1”, preferably wherein the glass fibers GF1” have a length of 30 mm or more, preferably 100 mm or more, annealing a/the polymer product PP2 comprising a/the polymer P2 and glass fibers GF1 ”, preferably wherein one or more, preferably all, of the following conditions is/are fulfilled: the temperature is at least once 250 °C or more and 1000 °C or less, preferably 320 °C or more and 800 °C or less, more preferably 350 °C or more and 800 °C or less, more preferably 450 °C or more and 600 °C or less; the annealing time is 0.1 h or more and 48 h or less, preferably 0.5 h or more and 24 h or less, more preferably 2 h or more and 6 h or less; and/or the annealing is performed in the presence of air, CO2, N2, Ar, or mixtures thereof, preferably air; and preferably and cutting, chopping and/or filtering, preferably through a sieve, more preferably through a sieve of 10 mm (mesh size) or less, more preferably 8 mm or less, more preferably 6 mm or less, more preferably 5 mm or less, more preferably 3 mm or less, more preferably 2 mm or less, more preferably 1 mm or less, the glass fibers GF1” after annealing to obtain the glass fibers GF1; preferably and wherein the glass fibers GF1” are glass fiber roving and/or glass fiber textiles.

11. Method, polymer compound PC1, polymer product PP1 or use according to any one of the preceding claims, wherein the glass fibers GF1 are uncoated.

12. Method, polymer compound PC1, polymer product PP1 or use according to any one of the preceding claims, wherein an organic content of the glass fibers GF1 is 1 weight-% or less, preferably 0.9 weight-% or less, more preferably 0.8 weight-% or less, more preferably 0.7 weight-% or less, more preferably 0.6 weight-% or less, more preferably 0.5 weight-% or less, more preferably 0.4 weight-% or less, more preferably 0.3 weight-% or less, more preferably 0.2 weight-% or less, more preferably 0.1 weight-% or less, more preferably 0.05 weight-% or less, more preferably 0.03 weight-% or less, more preferably 0.01 weight-% or less.

13. Method, polymer compound PC1, polymer product PP1 or use according to any one of the preceding claims, wherein a content of the glass fiber GF1 and/or GFT in the mixture M1, polymer compound PC1 or polymer product PP1 is 1 weight-% or more, preferably 2 weight-% or more, more preferably 3 weight-% or more, more preferably 4 weight-% or more, more preferably 5 weight-% or more, more preferably 10 weight-% or more, more preferably 15 weight-% or more, more preferably 20 weight-% or more, more preferably 21 weight-% or more, more preferably 25 weight-% or more, more preferably 30 weight-% or more, more preferably 35 weight-% or more, more preferably 40 weight-% or more, more preferably 45 weight-% or more; and/or wherein a content of the glass fiber GF1 and/or GFT in the mixture M1, polymer compound PC1 or polymer product PP1 is 50 weight-% or less, preferably 45 weight-% or less, more preferably 40 weight-% or less, more preferably 35 weight-% or less, more preferably 30 weight-% or less, more preferably 25 weight-% or less, more preferably 20 weight-% or less, more preferably 15 weight-% or less, more preferably 10 weight- % or less, more preferably 5 weight-% or less.

14. Method, polymer compound PC1, polymer product PP1 or use according to any one of the preceding claims, wherein the content of the polymer(s) and/or the glass fibers and/or the one or more additive(s) is/are determined based on identity preservation and/or segregation and/or mass balance and/or book and claim chain of custody models, preferably based on mass balance, preferably the International Sustainability and Carbon Certification (ISCC) standard.

15. Method, polymer compound PC1, polymer product PP1 or use according to any one of the preceding claims, wherein the method can be performed fast, is reproducible, and/or, preferably and, is less susceptible to failure, preferably is reproducible, and/or is less susceptible to failure; and/or wherein the polymer compound PC1 and/or the polymer product PP1 exhibits a predefined amount of recycled glass fibers GF1', a high amount of recycled glass fibers GFT, a specific length of recycled glass fibers GF1', improved mechanical properties, and/or, preferably and, improved sustainability.