RU2327712C1 - Method of polymer waste processing allowing to obtain construction material - Google Patents

Abstract

FIELD: construction.

SUBSTANCE: invention uses unsorted waste of thermoplastic polymers LDPE, HDPE, in an amount of 10-50 % weight. The waste is crushed in advance and mixed with clay with a humidity of 8-12 %. The product is formed and pressed at a specific pressure of 10MPa. After that, heat treatment is carried out at a temperature increase rate of 20°C/min. The duration of soaking at the polymer melting temperature is 90-180 minutes.

EFFECT: decreased energy consumption, simplification of method, and production of material with high technical performance.

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Description

The invention relates to the field of construction and can be used in the production of polymer, waste wall, decoration and road-building composite materials for civil engineering.

A known method of processing polymer waste to produce building material, including crushing waste, plasticizing and rolling (RF Patent No. 2002106847 "Method for processing polymer waste to produce building material") [1].

The disadvantage of this method is the complex technological scheme, including preliminary sorting of waste by color, grade and degree of contamination, washing and drying of ground waste, thermoplasticization with the introduction of an antioxidant and light stabilizer of secondary polyethylene and rolling. All these operations are not only labor-consuming and energy-intensive, but also require the use of expensive equipment and reagents, which significantly increases the cost of manufactured products.

Closest to the proposed invention is a method of manufacturing a facing sheet products from waste plastic film materials (RF Patent No. 2143443 "Method for the manufacture of sheet facing products from polymer waste") [2], including shredding the film, cleaning from dust and grease deposits, washing, drying , distribution and compaction of raw materials on the substrate until the finished product is cured.

The disadvantage of this method is the complexity of the technology and high energy consumption, namely the use of additional grinding and compression in an agglomerator with simultaneous coloring by introducing pigment dyes, additional densification at temperatures of 100-110 ° C for 3-8 minutes and final melting at temperatures of 160-180 ° C and pressing on a substrate.

The objective of the present invention is to reduce energy intensity and simplify the technological cycle of manufacturing products, and the use of affordable and cheap additional ingredients.

To achieve this goal, a technological approach is proposed, based on a two-stage technology, which provides for the cold pressing of products at the first stage and heat treatment (sintering) of products in the free state at the polymer melting point at the second stage. At the same time, the composite formulation contains at least two components, one of which ensures the preservation of the product shape after cold pressing (clay raw materials), and the other (waste thermoplastic polymers) acts after sintering as a binder that determines the necessary technical characteristics of the product that meet the requirements of technical conditions for specific types of products.

Unsorted waste of thermoplastic polymers (HDPE, LDPE) in an amount of 10-50 wt.% Is pre-crushed in a knife crusher, then mixed with clay with a moisture content of 8-12%, the resulting mixture is placed in a matrix of the required shape and the product is pressed on a hydraulic press at a specific pressure of 10 MPa The resulting material is dried at room temperature to constant weight and subjected to heat treatment. The rate of temperature rise is 20 ° C / min, the exposure time at the polymer melting point is 90-180 minutes, depending on the dimensions of the product.

The main physical and mechanical properties of materials manufactured by the proposed method are presented in table 1.

An analysis of the results showed that by varying the content of polymer waste in the composite, it is possible to control the properties of materials in a wide range and manufacture specific types of products in accordance with the requirements of regulatory and technical documents. The maximum possible content of polyethylene in the composite is set equal to 50 wt.%.

Table 1
The main physical and mechanical properties of composite materials No. Indicator The content of polymer wastes, wt.% 10 fifteen twenty thirty 40 fifty one Density, g / cm ³ 1.65 1,52 1.37 1.21 1.17 1.06 2 Compressive strength, MPa 9.11 11.01 10.76 16.12 18.27 20.45 3 Bending Strength, MPa 2.61 2.92 3.17 3.83 4.37 5.71 four Water absorption,% 6.21 6.14 6.03 5.87 5.12 4.73

Feasibility

Using the claimed invention, which is implemented on affordable and cheap equipment, can reduce energy consumption, simplify and shorten the technological cycle of manufacturing products by eliminating the operations of pre-sorting, washing and drying polymer waste, reduce the cost of production and obtain a building material with high technical and operational properties.

Information sources

1. RF patent No. 2002106847 "Method for the processing of polymer waste to produce building material" / M.A. Ermakov. - 8 p.

2. RF patent No. 2143443 "Method for the manufacture of sheet cladding products from polymer waste" / S.V. Menchov. - 7 p.

Claims (1)

A method of processing polymer waste to produce building material, characterized in that the unsorted waste of thermoplastic polymers (HDPE, LDPE) in an amount of 10-50 wt.% Is pre-crushed in a knife crusher, then mixed with clay with a moisture content of 8-12%, the resulting mixture is placed in the matrix of the required shape and the product is pressed at a specific pressure of 10 MPa, then the material is subjected to heat treatment in the following modes: the rate of temperature rise 20 ° C / min; the exposure time at a polymer melting point of 90-180 minutes