CN109878431B - A high-performance environment-friendly basalt fiber/hemp fiber reinforced resin composite automobile ceiling interior panel and preparation method thereof - Google Patents

Abstract

The invention discloses a high-performance environment-friendly basalt fiber/hemp fiber reinforced polypropylene composite automobile interior trim panel and a preparation method thereof, and belongs to the field of automobile interior trim parts manufacturing. The preparation method includes: natural freezing-mechanical combined degumming treatment of hemp fiber, modification treatment with coupling agent; adding coupling agent to modify basalt fiber after cryogenic treatment, and impregnating basalt fiber with micro-woven polypropylene fiber to make prepreg ; Then the three are made into a prefabricated body by means of solid-phase mixed fiber in proportion; finally, a car ceiling interior panel is made by molding. The invention solves the problems of difficult molding, low toughness, unenvironmental protection and the like of the automobile roof, and the produced products have the advantages of low density, light weight, high temperature resistance, impact resistance, low VOC, strong rigidity and toughness, high safety, outstanding environmental protection performance, etc. Features.

Description

A high-performance environment-friendly basalt fiber/hemp fiber reinforced resin composite automobile roof Interior panel and preparation method thereof

technical field

The invention belongs to the technical field of automobile interior decoration materials.

Background technique

With the rapid development of the automotive industry, people have higher and higher requirements for the quality and environmental performance of automotive interior parts. Nowadays, automotive materials are developing in the direction of composite, lightweight, recyclable, low VOC, and low energy consumption. Due to the defects of the existing composite substrates, they cannot meet the needs of the development of modern automotive materials. Therefore, natural Fiber composite materials are used in automotive interior parts to improve their overall performance.

The roof of the car is located on the top of the car and plays the role of decoration and energy absorption. In the prior art, the ceiling mainly has problems such as difficult molding, low toughness, poor impact resistance, complicated process, high scrap rate, difficult recycling, and unenvironmental protection. These problems restrict the development of automobile roof.

Hemp fiber is a fiber obtained from various hemp plants. The commonly used hemp fibers are hemp, jute, flax, sisal, ramie, etc. Hemp fiber has excellent properties such as antibacterial, sound-absorbing, anti-ultraviolet, moisture-absorbing and breathable, anti-static, anti-corrosion and heat-resistant.

Basalt fiber is a new type of inorganic environmentally friendly green high-performance fiber material, which is composed of oxides such as silica, alumina, calcium oxide, iron oxide and titanium dioxide. After basalt material is melted at high temperature, it is a continuous fiber drawn at high speed through a platinum-rhodium alloy wire drawing bushing. Basalt continuous fiber not only has good stability, but also has many excellent properties such as electrical insulation, corrosion resistance, combustion resistance and high temperature resistance.

Polypropylene, English abbreviation is PP. It has good heat resistance, dielectric properties, electrical insulation, corrosion resistance, stress crack resistance, low density and light weight. PP is more sensitive to the effect of oxygen, has poor anti-ultraviolet ability, poor low-temperature impact resistance, and is easy to age.

In the current industrial application process, hemp fiber reinforced polymer matrix composites have shortcomings such as excessive VOC and poor product mechanical properties.

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a high-performance environmentally friendly basalt fiber/hemp with low density, light weight, high temperature resistance, impact resistance, low VOC, strong rigidity and toughness, high safety and outstanding environmental protection performance in view of the deficiencies in the prior art. Fiber-reinforced polypropylene composite automobile ceiling trim panel and preparation method thereof.

The concrete steps of the technical solution adopted in the present invention are as follows:

Step 1: Hemp Fiber Pretreatment

1.1 Place the hemp fiber in a low temperature environment of -10 to 35 °C and freeze it for 30 to 60 days;

1.2 Degumming the frozen hemp fibers by mechanically rubbing and assisting in lye cleaning, and the lye solution is a strong alkaline solution with pH>13;

1.3 Silane coupling agent modifies the surface of hemp fiber;

Wherein, for the preparation of the coupling agent solution, at room temperature, take an appropriate amount of coupling agent into water, stir evenly, and then let stand for 1 hour; the coupling agent is selected from 450, 550, 601 or Any one of 803, the concentration of the coupling agent aqueous solution after stirring is adjusted to 1-35wt%; the hemp fiber is added to the coupling agent, kept at room temperature for 24 hours and stirred, then decanted, and then heated at 120 Cured at °C for 1 hour, dried in air for 24 hours, and cut into 70-100mm short fibers for use.

Step 2: Basalt Fiber Pretreatment

2.1 Use liquid nitrogen gas method for cryogenic treatment of basalt fibers; first pre-treat basalt fibers, soak them in acetone for half an hour, and then clean them with distilled water to remove surface impurities; use liquid nitrogen gas for low-temperature freezing treatment of basalt fibers, Cool down at a cooling rate of 2°C/min, first cool down to -80°C, hold at -80°C for 1 hour, then cool down to -120°C, hold for 1 hour, and finally cool down to -196°C, hold at -196°C for 12 hours; After the completion, the temperature is naturally returned to normal temperature, and the cryogenic treatment is completed.

2.2 silane coupling agent modifies the surface of basalt fiber; the preparation of described coupling agent solution is silane coupling agent KH550, and at normal temperature, by mass ratio water: silane coupling agent KH550: absolute ethanol is 1 : 1:20 to prepare KH550 solution, stir well, and then let stand for 1 hour; take KH550 solution accounting for 1.0% of the mass of basalt fiber to process basalt fiber, after 30 minutes of reaction, put the basalt fiber into a 100 ℃ oven to dry, That is, the modified basalt fiber is obtained.

2.3 Prepreg is made by impregnating basalt fiber with micro-woven resin fiber; put the wound resin fiber and basalt fiber in an oven, preheat at 130°C for 10min, raise the temperature to 170-200°C, and the heating time is 30 -60min, take out, cool, dry, cut into short fibers of 70-100mm for use.

Step 3: Resin Fiber Pretreatment

The resin fiber was soaked in acetone for half an hour, then washed with distilled water to remove surface impurities, and then dried.

Step 4: Prepare the Prefab

The short fibers of the hemp fibers and basalt fibers processed by the above-mentioned steps are weighed according to the ratios that the hemp fibers and the basalt fibers account for 60% by weight of the total prefabricated fiber weight (the hemp fibers are 40-59% by weight. , basalt fiber weight is 1-20%) mixed with resin fiber, and then open, carded into a net and needle punched into a felt to make a prefabricated body.

Step 5: Prepare the Ceiling Trim Panel

5.1 Preheating the prefabricated parts; the temperature of the preheating treatment is 150-260°C, and the time of the preheating treatment is 10-20min;

5.2 Spread it on the auto ceiling interior trim panel mold, and press molding to prepare the product auto ceiling interior trim part; the molding pressure of the molding on the auto ceiling interior trim panel mold is 10-20MPa, and the pressure holding time is 15-30min.

Beneficial effects of the present invention:

The automobile ceiling interior trim panel prepared by the invention has the advantages of low density, light weight, high temperature resistance, impact resistance, low VOC, strong rigidity and toughness, high safety, outstanding environmental protection performance and the like.

Description of drawings

Fig. 1 is the production process schematic diagram of the present invention.

Detailed ways

The technical solutions of the present invention will be explained and described below by way of specific embodiments.

Example 1

Step 1: Hemp Fiber Pretreatment

(1) Natural freezing-mechanical rubbing treatment, assisted cleaning with lye, to obtain the desired hemp fiber. Natural freezing is to use the natural conditions of winter (-10 ~ -35 ℃) in Northeast China to freeze hemp fibers for 30 to 60 days, and use the thermal shock caused by the temperature difference to cause microcracks between different components. , and then use the method of mechanical rubbing to assist the lye to clean and remove pectin, lignin, hemicellulose, etc., so as to achieve the purpose of degumming and reduce VOC. The lye is a strong alkaline solution with pH>13.

(2) Select 450 coupling agent and adjust its concentration to 25%, add hemp fiber to the coupling agent, keep at room temperature for 24 hours with stirring from time to time, then decant, and then solidify at 120 ° C for 1 hour, the It was air dried for 24 hours. Complete the modification treatment of hemp fiber. Cut into 70mm for later use.

Step 2: Basalt Fiber Pretreatment

(1) Soak the basalt fiber in acetone for half an hour, and then clean it with distilled water; the basalt fiber is kept at a cooling rate of 2 °C/min, kept at -80 °C for 1 hour, and at -120 °C for 1 hour, and the final heat preservation temperature is -196 ℃, holding time for 12h, natural return to temperature. Complete cryogenic treatment of basalt fibers.

(2) The prepared KH550 solution, which accounts for 1.0% of the mass of the basalt fiber, is used to treat the basalt fiber, and after 30 minutes of reaction, the basalt fiber is placed in a 100° C. oven for drying to obtain the modified basalt fiber.

(3) Put the wound polypropylene fiber and basalt fiber into an oven, preheat at 130°C for 10min, raise the temperature to 170°C, heat for 60min, take out, cool, dry, and cut into 70mm for use.

Step 3: Prepare the Prefab

(1) Soak the PP fiber in acetone for half an hour, then clean it with distilled water and dry it.

(2) The short fibers of the processed hemp fibers and basalt fibers are mixed with PP fibers according to the weight of the hemp fibers as 55% and the weight of the basalt fibers as 5%. into a prefab.

Step 4: Prepare the ceiling trim panel

(1) Preheat the preform at a temperature of 170° C. and a time of 15 minutes.

(2) Spread the preheated composite material on the mould of the interior panel of the automobile ceiling, the moulding pressure is 15MPa, and the time is 20min.

Example 2

Step 1: Jute Fiber Pretreatment

(1) Natural freezing, mechanical rubbing treatment, and lye-assisted cleaning to obtain the required hemp fiber, the method is the same as that in Example 1.

(2) Select 550 coupling agent and adjust its concentration to 16.7%, add hemp fiber to the coupling agent, keep at room temperature for 24 hours with stirring from time to time, then decant, and then solidify at 120 ° C for 1 hour. It was air dried for 24 hours. Complete the modification treatment of hemp fiber.

Step 2: Basalt Fiber Pretreatment

(1) Soak the basalt fiber in acetone for half an hour, and then clean it with distilled water; the basalt fiber is kept at a cooling rate of 2°C/min, kept at -80°C for 1 hour, and at -120°C for 1 hour, and the final heat preservation temperature is -196 ℃, holding time for 12h, natural return to temperature. Complete cryogenic treatment of basalt fibers.

(2) The prepared KH550 solution, which accounts for 1.0% of the mass of the basalt fiber, is used to treat the basalt fiber, and after 30 minutes of reaction, the basalt fiber is placed in a 100° C. oven for drying to obtain the modified basalt fiber. Cut into 85mm for later use.

(3) Put the wound polypropylene fiber and basalt fiber into an oven, preheat at 130°C for 10min, raise the temperature to 185°C, heat for 45min, take out, cool, dry, and cut into 85mm for use.

Step 3: Prepare the Prefab

(1) Soak the PP fiber in acetone for half an hour, then clean it with distilled water and dry it.

(2) The short fibers of the processed hemp fibers and basalt fibers are mixed with PP fibers according to the weight of the hemp fibers as 50% and the weight of the basalt fibers as 10%. into a prefab.

Step 4: Prepare the ceiling trim panel

(1) Preheat the preform at a temperature of 175°C and a time of 12min.

(2) Spread the preheated composite material on the mould of the interior panel of the automobile ceiling, the moulding pressure is 18MPa, and the time is 18min.

Example 3

Step 1: Flax Fiber Pretreatment

(1) Natural freezing, mechanical rubbing treatment, and lye-assisted cleaning to obtain the required hemp fiber, the method is the same as that in Example 1.

(2) Select 601 coupling agent and adjust its concentration to 25%, add hemp fiber to the coupling agent, keep at room temperature for 24 hours with stirring from time to time, then decant, and then solidify at 120 ° C for 1 hour, the It was air dried for 24 hours. Complete the modification treatment of hemp fiber.

Step 2: Basalt Fiber Pretreatment

(1) Soak the basalt fiber in acetone for half an hour, and then clean it with distilled water; the basalt fiber is kept at a cooling rate of 2°C/min, kept at -80°C for 1 hour, and at -120°C for 1 hour, and the final heat preservation temperature is -196 ℃, holding time for 12h, natural return to temperature. Complete cryogenic treatment of basalt fibers.

(2) The prepared KH550 solution, which accounts for 1.0% of the mass of the basalt fiber, is used to treat the basalt fiber, and after 30 minutes of reaction, the basalt fiber is placed in a 100° C. oven for drying to obtain the modified basalt fiber. Cut into 100mm for later use.

(3) Put the wound polypropylene fiber and basalt fiber into an oven, preheat at 130°C for 10min, raise the temperature to 200°C, heat for 30min, take out, cool, dry, cut into 70-100mm for use .

Step 3: Prepare the Prefab

(1) Soak the PP fiber in acetone for half an hour, then clean it with distilled water and dry it.

(2) The short fibers of the processed hemp fibers and basalt fibers are mixed with PP fibers according to the weight of the hemp fibers as 45% and the weight of the basalt fibers as 15%. into a prefab.

Step 4: Prepare the ceiling trim panel

(1) Preheat the preform at a temperature of 180° C. and a time of 10 minutes.

(2) Spread the preheated composite material on the mould of the interior panel of the automobile ceiling, the moulding pressure is 20MPa, and the time is 15min. technical effect test

Performance tests were performed on Examples 1-3, including tensile strength testing, flexural modulus testing, burning speed and cumulative VOC release testing.

Table 1

The specific data of the test results are shown in Table 1, indicating that the automotive ceiling interior trim panel prepared by the method of the present invention has excellent performance, low density, light weight, high temperature resistance, impact resistance, low VOC, strong rigidity and high safety. .

Claims (2)

1. a preparation method of high-performance environmental protection basalt fiber/hemp fiber reinforced polypropylene composite automobile ceiling interior panel, the method concrete steps are as follows: Step 1: Hemp Fiber Pretreatment 1.1 Place the hemp fiber in a low temperature -10~35℃ natural environment for freezing treatment; 1.2 Degumming the frozen hemp fibers by mechanically rubbing and assisting in lye cleaning, and the lye solution is a strong alkaline solution with pH>13; 1.3 The silane coupling agent modifies the surface of the hemp fiber; the hemp fiber is added to the coupling agent solution, kept at room temperature for 24 hours and stirred, then decanted, and then cured at 120 ° C for 1 hour, and it was placed in the air. Dry in medium for 24 hours, cut into 70-100mm short fibers for use; Wherein, for the preparation of the coupling agent solution, at room temperature, take an appropriate amount of coupling agent into water, stir evenly, and then let stand for 1 hour; the coupling agent is selected from 450, 550, 601 or Any one of 803, the concentration of the coupling agent solution after stirring is adjusted to 1~35wt%; Step 2: Basalt Fiber Pretreatment 2.1 Use liquid nitrogen gas method for cryogenic treatment of basalt fibers; first pre-treat basalt fibers, soak them in acetone for half an hour, and then clean them with distilled water to remove surface impurities; use liquid nitrogen gas for low-temperature freezing treatment of basalt fibers, Cool down at a cooling rate of 2°C/min, first cool down to -80°C, hold at -80°C for 1 hour, then cool down to -120°C, hold for 1 hour, and finally cool down to -196°C, hold at -196°C for 12 hours; After the completion, the temperature is naturally returned to normal temperature, and the cryogenic treatment is completed; 2.2 Silane coupling agent modifies the surface of basalt fiber; for the preparation of silane coupling agent solution, silane coupling agent KH550 is selected, and the ratio of water: silane coupling agent KH550: absolute ethanol is 1:1 by mass at room temperature : 20 to prepare a KH550 solution, fully stirred, and then let stand for 1 h; take the KH550 solution accounting for 1.0% of the mass of the basalt fiber to treat the basalt fiber, and after 30 minutes of reaction, put the basalt fiber into a 100 ℃ oven for drying to obtain Modified basalt fiber; 2.3 Impregnate basalt fiber with micro-woven resin fiber to make prepreg; put the wound resin fiber and the modified basalt fiber obtained in step 2.2 into an oven, preheat at 130°C for 10min, and raise the temperature to 170-200°C ℃, heating time is 30-60min, take out, cool, dry, cut into short fibers of 70-100mm for use; Step 3: Resin Fiber Pretreatment Soak the resin fiber in acetone for half an hour, then clean it with distilled water to remove surface impurities, and then dry it; Step 4: Prepare the Prefab The hemp fiber and the short fiber of the basalt fiber processed by the above steps are 60% (the hemp fiber weight is 40-60%, the basalt fiber weight is 1-20%) according to the total weight of the hemp fiber and the basalt fiber, and the total weight of the hemp fiber and the basalt fiber is 1-20%. The treated resin fibers are mixed, then opened, combed into a net, and needle punched into a felt to make a preform; Step 5: Prepare the Ceiling Trim Panel 5.1 Preheat the preform; the temperature of the preheat treatment is 150-260°C, and the time of the preheat treatment is 10-20min; 5.2 Spread it on the auto ceiling interior trim panel mold, and press molding to prepare the product auto ceiling interior trim part; the molding pressure of the molding on the auto ceiling interior trim panel mold is 10-20MPa, and the pressure holding time is 15-30min. 2. A high-performance environment-friendly basalt fiber/hemp fiber reinforced polypropylene composite automobile ceiling trim panel prepared by the method of claim 1.

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