A dry process automobile interior ceiling substrate and preparation method thereof

Abstract

The present application relates to the technical field of automobile roof systems, and specifically discloses a dry process automobile interior ceiling substrate and a preparation method thereof. A dry process automobile interior ceiling substrate comprises a base layer and a reinforcement layer, both of which are multi-layer structures; a skylight reinforcement frame is arranged on the base layer, and the reinforcement layer is arranged inside the base layer between the boundary of the skylight reinforcement frame close to one end of the automobile front and the boundary of the substrate close to one end of the automobile front. A dry process automobile interior ceiling substrate of the present application is suitable for preparing an automobile ceiling with a skylight structure, and has the advantages of light weight and low odor, while having sufficient rigidity and strength to assemble various secondary parts, meeting the modular supply requirements of automobile ceilings.

Description

Technical Field

[0001] The present application relates to the technical field of automobile roof systems, and more specifically, to a dry process automobile interior ceiling substrate and a preparation method thereof. Background Art

[0002] With the rapid development of the modern automobile industry, the efficiency of vehicle assembly lines has been continuously improved, and the production speed of vehicle factories has reached the level of one vehicle off the line every minute. The efficient production rhythm has put forward higher requirements on the supply of automotive parts, especially the automotive interior represented by the ceiling, which needs to be supplied in a modular manner. This not only requires the ceiling body to provide sufficient structural rigidity to support the turnover of various secondary parts, such as headlight brackets, headlights, wiring harnesses, anti-collision energy absorption blocks or energy absorption brackets, sun visors, handles, air conditioning ducts, etc., but also needs to remain stable during transportation and assembly to avoid damage. Usually, the weight of the sandwich substrate of this modular ceiling is ≥1000g / m 2 .

[0003] As consumers' requirements for the quality of car interiors are increasing, the air quality inside the car and the environmental performance of interior materials have become the focus of attention of car manufacturers. As early as 2011, the country issued the "Guidelines for Passenger Car Interior Air Quality Evaluation" (GB / T27630-2011), which regulated the air quality inside the car and put forward strict requirements for the odor and volatile organic compound (VOC) content of automotive interior parts. There is no best in odor control, only better.

[0004] In addition, with the global emphasis on energy conservation and emission reduction, the automotive industry is also facing the challenge of green and low-carbon development. On December 7, 2023, the Ministry of Industry and Information Technology issued the "Green and Low-Carbon Development Route for the Automotive Industry". Figure 1 .0, which clearly stipulates the path for carbon emission reduction of passenger cars, requires continuous optimization of automobile energy-saving technology, and reduces the fuel consumption of traditional energy passenger cars. By 2025 and 2030, the average fuel consumption of traditional energy new cars will reach 4.6L / 100km and 3.0L / 100km respectively. At the same time, it requires continuous improvement of the technical level of new energy vehicles and acceleration of the popularization of new energy passenger cars. By 2025, the power consumption of pure electric passenger cars must reach 12kWh / 100km. In this context, the lightweight design of automotive parts has become the key to achieving energy conservation and carbon reduction goals.

[0005] With regard to the above-mentioned related technologies, the inventors found that the traditional wet manufacturing process of automobile roofs uses liquid glue for molding and fabric compounding, which not only increases production costs and product weight, but also leads to an increase in product odor. The dry manufacturing process for preparing automobile roofs also has the problems of heavy weight and insufficient rigidity, which cannot meet the multiple demands of the modern automobile industry for efficiency, environmental protection and lightweight. Summary of the invention

[0006] In order to reduce the odor and weight of automobile interior ceilings, improve the rigidity of automobile interior ceiling substrates, and meet the multiple demands of the modern automobile industry for production efficiency, environmental protection and lightweight, the present application provides a dry process automobile interior ceiling substrate and a preparation method thereof.

[0007] In the first aspect, the present application provides a dry process automobile interior ceiling substrate, which adopts the following technical solution:

[0008] A dry process automobile interior ceiling substrate, comprising a base layer and a reinforcement layer, wherein both the base layer and the reinforcement layer are multi-layer structures;

[0009] A sunroof reinforcement frame is arranged on the base layer, and the reinforcement layer is arranged inside the base layer between a boundary of the sunroof reinforcement frame close to one end of the automobile front and a boundary of the substrate close to one end of the automobile front.

[0010] By adopting the above technical scheme, in this application, the reinforcement layer is arranged at the front end area of ​​the automobile interior ceiling substrate close to the front windshield to form a sandwich substrate. This can not only maximize the lightweight of the finished ceiling, but also ensure that the automobile ceiling has sufficient rigidity to meet the assembly requirements of any one or more secondary parts such as lamp brackets, lamps, wiring harnesses, anti-collision energy absorbing blocks or energy absorbing brackets, sun visors, handles, air-conditioning ducts, etc. on the automobile ceiling, realize the modular supply needs of lightweight automobile ceilings, and ensure that the automobile roof remains in good condition without damage during turnover, storage, transportation and assembly.

[0011] Optionally, the base layer includes, from bottom to top, a first fabric layer, a first glass fiber layer, a first rubber powder layer, a first rubber film layer, a PU foam layer, a second rubber film layer, a second glass fiber layer, a second rubber powder layer and a third rubber film layer.

[0012] Optionally, the reinforcement layer is arranged inside the base layer, and the reinforcement layer includes, from bottom to top, a second fabric layer, a third glass fiber layer, a third rubber powder layer and a fourth film layer, the lower side of the second fabric layer contacts the upper side of the first film layer, and the upper side of the fourth film layer contacts the lower side of the PU foam layer.

[0013] By adopting the above technical scheme, by arranging the layers in the base layer and the reinforcement layer in a specific manner and then placing the reinforcement layer in a specific position in the base layer, the rigidity and strength requirements of the automobile interior ceiling substrate are guaranteed to the maximum extent, and the layers can be stably and smoothly bonded together. The automobile interior substrate prepared in this way saves materials, meets the lightweight requirements, and reduces costs.

[0014] Optionally, the raw materials of the first rubber powder layer, the second rubber powder layer and the third rubber powder layer include rubber powder and lamellar silicate minerals in a mass ratio of 1:(0.13-0.22).

[0015] By adopting the above technical solution, the lamellar silicate mineral has the characteristics of high strength and toughness, low density, lighter weight, and is a natural and environmentally friendly material. After mixing with rubber powder, it can serve as a reinforcing phase to significantly improve the stiffness of the composite material matrix, so that the composite material matrix exhibits higher bending strength and modulus.

[0016] On the one hand, lamellar silicate minerals can form an interpenetrating network structure when mixed with rubber powder. These lamellar structures can absorb and disperse stress like a "cushion", reduce stress concentration and crack expansion, thereby improving the strength and toughness of the substrate, making it more resistant to damage when facing external forces such as impact or vibration.

[0017] On the other hand, when the mixture of rubber powder and lamellar silicate minerals is spread on the glass fiber layer, the lamellar silicate minerals can make the bonding between the layers stronger. This may be because the lamellar silicate minerals are polar materials. The compatibility between the composite materials is further improved. The lamellar silicate minerals can form a mechanical lock with the glass fiber at the microscopic level, thereby increasing the friction between the glass fiber layer and the rubber powder and film layer. This interlayer friction helps to improve the cohesion and peeling force of the overall composite material, and also prevents the occurrence of glue seepage after molding.

[0018] Optionally, the first adhesive film layer, the second adhesive film layer, the third adhesive film layer and the fourth adhesive film layer are all modified polypropylene adhesive films.

[0019] Optionally, the method for preparing the modified polypropylene film comprises the following steps:

[0020] The polypropylene particles are uniformly mixed with maleic anhydride and glycidyl methacrylate in a mass ratio of 10:(1-1.5):(0.3-0.6), and then dicumyl peroxide is added for blending; the blend is added into a screw extruder, and a melt grafting reaction is carried out at 220-240° C. and a rotation speed of 65-75 r / min for 10-15 minutes, and a film is formed by extrusion and cooled and solidified to obtain the product.

[0021] By adopting the above technical scheme, polypropylene is melt-grafted and modified, and polar groups such as active carboxylic acid functional groups and epoxy groups are introduced into polypropylene, thereby increasing the polar interactions between polypropylene molecular chains. This helps to improve the compatibility between composite materials, reduce the migration of small molecules caused by incompatibility, and increase the odor of the material. At the same time, it improves the interface bonding between layers, especially the bonding between the film layer and the PU foam layer. The modified polypropylene film has stronger penetration into the PU foam layer and can form a chemical bonding of the riveted structure.

[0022] The modification of polypropylene by mixing glycidyl methacrylate and maleic anhydride has a better effect than modification by single maleic anhydride. This may be because glycidyl methacrylate provides additional epoxy groups to react with the active carboxyl groups of maleic anhydride to form a more complex network structure, further improving the adhesion and mechanical strength of the modified polypropylene film.

[0023] Optionally, the raw materials of the first glass fiber layer, the second glass fiber layer and the third glass fiber layer are all TCR glass fibers.

[0024] By adopting the above technical solution, boron-free and fluorine-free TCR glass fiber is used, which is more environmentally friendly than traditional GF glass fiber and helps to further reduce the odor of the automotive interior ceiling substrate.

[0025] In a second aspect, the present application provides a method for preparing a substrate for an automobile interior ceiling by a dry process, which adopts the following technical solution:

[0026] A method for preparing a substrate for an automobile interior ceiling by a dry process comprises the following steps:

[0027] S1: Laying non-woven fabric flat as the second fabric layer, cutting and spreading glass fibers on the second fabric layer in sequence, spreading rubber powder or a mixture of rubber powder and lamellar silicate minerals, laying adhesive film as the third glass fiber layer, the third rubber powder layer and the fourth adhesive film layer, heating, pressing and cooling at a preset temperature and conveying speed to obtain a reinforcement layer;

[0028] S2: Lay the non-woven fabric flatly as the first fabric layer, and cut, spread or lay glass fiber, rubber powder or a mixture of rubber powder and lamellar silicate minerals, rubber film, reinforcement layer, PU foam board, rubber film, glass fiber, rubber powder or a mixture of rubber powder and lamellar silicate minerals and rubber film on the first fabric layer in sequence as the first glass fiber layer, the first rubber powder layer, the first rubber film layer, the reinforcement layer, the PU foam layer, the second rubber film layer, the second glass fiber layer, the second rubber powder layer and the third rubber film layer, respectively, and heat, press and cool at a preset temperature and conveying speed to obtain a car interior ceiling substrate.

[0029] Optionally, the weight of the reinforcement layer is 140±20g / m 2 .

[0030] Optionally, in the reinforcement layer, the weight of the third glass fiber layer is 40±3g / m 2 The weight of the third rubber powder layer is 40±4g / m 2 The weight of the fourth film layer is 30±5g / m 2 .

[0031] By adopting the above technical scheme, the multilayer materials in the base layer and the reinforcement layer of the present application are bonded together by the heat-melting of the rubber powder and the rubber film during the process of compounding and integral molding. The entire process does not involve the use of liquid glue, which significantly reduces the odor and weight of the automotive interior ceiling substrate, and the process environment is cleaner and more hygienic, which is a green production process with sustainable development.

[0032] The gram weight in this application is 140±20g / m 2 The thickness of the reinforcement layer is less than 1mm, the PU foam layer has good compression performance, the front and back sides of the composite sandwich substrate are very flat, and the layers of material are well bonded.

[0033] In summary, this application has the following beneficial effects:

[0034] 1. The present application arranges a reinforcing layer in the front end area of ​​the base layer of the automobile interior ceiling substrate near the front windshield to form a sandwich substrate. This ensures that the automobile roof has sufficient rigidity and strength to assemble various secondary parts, meets the modular supply requirements of the automobile roof, and prevents the automobile roof from being damaged during turnover, transportation and assembly. It also maximizes the lightweight of the automobile interior ceiling substrate.

[0035] 2. In this application, rubber powder and lamellar silicate minerals are preferably used as raw materials for the rubber powder layer, and glycidyl methacrylate and maleic anhydride melt-grafted modified polypropylene are used as the film material, which effectively improves the mechanical properties of the automotive interior ceiling substrate, while further reducing the odor of the substrate, making it more environmentally friendly.

[0036] 3. This application adopts a dry process to achieve the compounding and molding of multiple layers of materials in the base layer and the reinforcement layer of the automobile interior ceiling substrate, which significantly reduces the odor and weight of the automobile interior ceiling substrate, and the process environment is cleaner and more hygienic, and is a green production process for sustainable development. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a top view of a dry process automobile interior ceiling substrate of the present application.

[0038] Figure 2This is a schematic diagram of the structure of a dry process automobile interior ceiling substrate material of the present application.

[0039] Figure 3 It is a structural schematic diagram of the reinforcement layer in this application.

[0040] Description of the accompanying drawings: 1. Base layer; 11. First fabric layer; 12. First glass fiber layer; 13. First rubber powder layer; 14. First film layer; 15. PU foam layer; 16. Second film layer; 17. Second glass fiber layer; 18. Second rubber powder layer; 19. Third film layer; 2. Reinforcement layer; 21. Second fabric layer; 22. Third glass fiber layer; 23. Third rubber powder layer; 24. Fourth film layer; 3. Skylight reinforcement frame; 31. Skylight opening. DETAILED DESCRIPTION

[0041] The following examples further illustrate the present application in detail.

[0042] raw material

[0043] Unless otherwise specified, the raw materials used in the examples and comparative examples of this application are all commercially available products, specifically:

[0044] Polypropylene, selected from Formosa Plastics Polypropylene, PP3090;

[0045] Non-woven fabric, PET non-woven fabric, weight 30±5g / m 2 ;

[0046] The rubber powder is HDPE rubber powder with a particle size range of 110-220μm;

[0047] The glass fiber is TCR glass fiber, which is a continuous twisted roving drawn from TCR glass and is obtained after being impregnated with a low-odor silane coupling agent. The length of the glass fiber of the first glass fiber layer is 2 inches, and the length of the glass fiber of the second and third glass fiber layers is 1 inch.

[0048] The lamellar silicate mineral is bentonite, selected from BYK, OPTIGEL-WX.

[0049] Preparation example of modified polypropylene film

[0050] Preparation Example 1

[0051] The modified polypropylene film and its preparation method include the following steps:

[0052] 10 parts by weight of polypropylene particles are uniformly mixed with 1 part by weight of maleic anhydride and 0.3 parts by weight of glycidyl methacrylate, and then 0.1 parts by weight of dicumyl peroxide are added for blending; the blend is added into a screw extruder, and a melt grafting reaction is carried out at 240° C. and a rotation speed of 70 r / min for 15 minutes, and a film is formed by extrusion and cooled and solidified to obtain the obtained product.

[0053] Preparation Example 2

[0054] The modified polypropylene film and its preparation method include the following steps:

[0055] 10 parts by weight of polypropylene particles are uniformly mixed with 1.5 parts by weight of maleic anhydride and 0.5 parts by weight of glycidyl methacrylate, and then 0.1 parts by weight of dicumyl peroxide are added for blending; the blend is added into a screw extruder, and a melt grafting reaction is carried out at 220° C. and a rotation speed of 65 r / min for 15 minutes, and a film is formed by extrusion and cooled and solidified to obtain the product.

[0056] Preparation Example 3

[0057] The modified polypropylene film and its preparation method include the following steps:

[0058] 10 parts by weight of polypropylene particles are uniformly mixed with 1.2 parts by weight of maleic anhydride and 0.4 parts by weight of glycidyl methacrylate, and then 0.1 parts by weight of dicumyl peroxide are added for blending; the blend is added into a screw extruder, and a melt grafting reaction is carried out at 240° C. and a rotation speed of 75 r / min for 10 minutes, and a film is formed by extrusion and cooled and solidified to obtain the product.

[0059] Preparation Example 4

[0060] The modified polypropylene film and its preparation method include the following steps:

[0061] 10 parts by weight of polypropylene particles and 1.3 parts by weight of maleic anhydride are uniformly mixed, and then 0.1 parts by weight of diisopropylbenzene peroxide are added for blending; the blend is added into a screw extruder, and melt grafting reaction is carried out at 240° C. and 70 r / min for 15 minutes, and a film is formed by extrusion and cooled and solidified to obtain the product. Example Example 1

[0062] A dry process automobile interior ceiling substrate extends from one end of the front windshield of the automobile to the rear of the automobile, such as Figure 1 and Figure 2 As shown, it includes a base layer 1 and a reinforcement layer 2, both of which are composed of a multi-layer structure. A skylight reinforcement frame 3 is arranged on the top of the base layer 1, and a skylight opening 31 is opened in the center of the skylight reinforcement frame 3 for subsequent installation of the car roof skylight.

[0063] The reinforcement layer 2 is arranged inside the base layer 1 on the side of the sunroof reinforcement frame 3 close to the front windshield of the car (see Figure 1 The base layer 1 includes, from bottom to top, a first fabric layer 11, a first glass fiber layer 12, a first rubber powder layer 13, a first film layer 14, a PU foam layer 15, a second film layer 16, a second glass fiber layer 17, a second rubber powder layer 18 and a third film layer 19. The reinforcement layer 2 is disposed between the first film layer 14 and the PU foam layer 15.

[0064] like Figure 3 As shown, the reinforcing layer 2 comprises, from bottom to top, a second fabric layer 21, a third glass fiber layer 22, a third rubber powder layer 23 and a fourth film layer 24, wherein the lower side of the second fabric layer 21 contacts the upper side of the first film layer 14, and the upper side of the fourth film layer 24 contacts the lower side of the PU foam layer 15.

[0065] In the reinforcement layer 2, the third glass fiber layer 22 has a gram weight of 40±3 g / m 2 The weight of the third rubber powder layer 23 is 40±4g / m 2 The fourth adhesive film layer 24 has a gram weight of 30±5 g / m 2 In the base layer 1, the first glass fiber layer 12 and the second glass fiber layer 17 have a gram weight of 130±3 g / m 2 The weight of the first adhesive film layer 14, the second adhesive film layer 16 and the third adhesive film layer 19 are all 30±3g / m 2 The weight of the first rubber powder layer 13 is 110±4 g / m 2 The weight of the second rubber powder layer 18 is 60±4g / m 2 .

[0066] The above-mentioned method for preparing the automobile interior ceiling substrate by dry process comprises the following steps:

[0067] S1: PET non-woven fabric is evenly laid on the conveyor belt of the composite production line as the second fabric layer 21, TCR glass fiber is cut and spread on the second fabric layer 21 in sequence, HDPE rubber powder is spread, and the modified polypropylene film obtained in Preparation Example 4 is laid as the third glass fiber layer 22, the third rubber powder layer 23 and the fourth film layer 24, and a crawler-type special conveying device is used to heat at a conveying speed of (6±0.2) m / min at 180±20°C, press and cool to obtain a gram weight of 160 g / m 2 The reinforcement layer 2 is cut into a specification of 1300 mm × 900 mm;

[0068] S2: PET non-woven fabric is evenly laid on the conveyor belt of the composite production line as the first fabric layer 11, and TCR glass fiber, HDPE rubber powder, modified polypropylene film obtained in Preparation Example 4, reinforcing layer 2, PU foam board, modified polypropylene film obtained in Preparation Example 4, TCR glass fiber, HDPE rubber powder and modified polypropylene film obtained in Preparation Example 4 are sequentially cut, spread or laid on the first fabric layer 11 as the first glass fiber layer 12, the first rubber powder layer 13, the first film layer 14, the reinforcing layer 2, the PU foam layer 15, the second film layer 16, the second glass fiber layer 17, the second rubber powder layer 18 and the third film layer 19, respectively, and a crawler-type special conveying device is used to heat at a conveying speed of (8±0.2) m / min at 210±20°C, press and cool to obtain a gram weight of (750±10) g / m 2 Sandwich structure automotive interior ceiling substrate.

[0069] The sandwich substrate obtained in the present application is heated (24±3)s in a secondary heating method of preheating and heating in a heating furnace with upper and lower furnace temperatures of (310±10)℃ and (240±10)℃ respectively. After heating, the sandwich substrate and fabrics of different structures are automatically introduced into the same or different cold molds for cold pressing. During the pressing process, the mold temperature is ≤25℃, the quoted time is (24±3)s, and the pressure holding pressure is 60bar, and the initial shape of the automobile roof can be obtained. The fabric used can be a non-woven fabric, a composite fabric of warp knitting and foam, or a composite fabric of suede and foam, etc. The skylight reinforcement frame is placed in the skylight reinforcement frame position of the lower mold during the heating process of the sandwich substrate, and then the scraps of the post-process are removed, and the skylight opening processing and the assembly of secondary parts such as lamp brackets and lamps are completed as needed. Example 2

[0070] A dry process automobile interior ceiling substrate, which is different from Example 1 in that its preparation method comprises the following steps:

[0071] S1: PET non-woven fabric is evenly laid on the conveyor belt of the composite production line as the second fabric layer 21, TCR glass fiber is cut and spread on the second fabric layer 21 in sequence, a mixture of HDPE rubber powder and lamellar silicate minerals with a mass ratio of 1:0.2 is spread, and the modified polypropylene film obtained in Preparation Example 4 is laid as the third glass fiber layer 22, the third rubber powder layer 23 and the fourth film layer 24, and a crawler-type special conveying device is used to heat at a conveying speed of (6±0.2) m / min at 180±20°C, press and cool to obtain a gram weight of 152 g / m 2 The reinforcement layer 2 is cut into a specification of 1300 mm × 900 mm;

[0072] S2: PET non-woven fabric is evenly laid on the conveyor belt of the composite production line as the first fabric layer 11, and TCR glass fiber, a mixture of HDPE rubber powder and lamellar silicate minerals in a mass ratio of 1:0.2, the modified polypropylene film obtained in Preparation Example 4, the reinforcement layer 2, the PU foam board, the modified polypropylene film obtained in Preparation Example 4, TCR glass fiber, a mixture of HDPE rubber powder and lamellar silicate minerals in a mass ratio of 1:0.2 are sequentially cut, spread or laid on the first fabric layer 11. The mixture of silicate minerals and the modified polypropylene film obtained in Preparation Example 4 are respectively used as the first glass fiber layer 12, the first rubber powder layer 13, the first film layer 14, the reinforcement layer 2, the PU foam layer 15, the second film layer 16, the second glass fiber layer 17, the second rubber powder layer 18 and the third film layer 19, and a crawler-type special conveyor is used to heat at a conveying speed of (8±0.2) m / min at 210±20°C, press and cool to obtain a gram weight of (750±10) g / m 2 Sandwich structure automotive interior ceiling substrate. Example 3

[0073] A dry process automobile interior ceiling substrate, which is different from Example 2 in that the raw materials of the first rubber powder layer 13, the second rubber powder layer 18 and the third rubber powder layer 23 are all a mixture of HDPE rubber powder and lamellar silicate minerals in a mass ratio of 1:0.13, and the other steps are the same as Example 2, wherein the gram weight of the reinforcement layer 2 is 155g / m 2 . Example 4

[0074] A dry process automobile interior ceiling substrate, which is different from Example 2 in that the raw materials of the first rubber powder layer 13, the second rubber powder layer 18 and the third rubber powder layer 23 are all a mixture of HDPE rubber powder and lamellar silicate minerals in a mass ratio of 1:0.22, and the other steps are the same as Example 2, wherein the gram weight of the reinforcement layer 2 is 150g / m 2 . Example 5

[0075] A dry process automobile interior ceiling substrate, which is different from Example 2 in that the first adhesive film layer 14, the second adhesive film layer 16, the third adhesive film layer 19 and the fourth adhesive film layer 24 are all modified polypropylene adhesive films obtained in Preparation Example 1, and the other steps are the same as in Example 2, wherein the gram weight of the reinforcement layer 2 is 140 g / m 2 . Example 6

[0076] A dry process automobile interior ceiling substrate, which is different from Example 2 in that the first adhesive film layer 14, the second adhesive film layer 16, the third adhesive film layer 19 and the fourth adhesive film layer 24 are all modified polypropylene adhesive films obtained in Preparation Example 2, and the other steps are the same as in Example 2, wherein the gram weight of the reinforcement layer 2 is 148 g / m 2 . Example 7

[0077] A dry process automobile interior ceiling substrate, which is different from Example 2 in that the first adhesive film layer 14, the second adhesive film layer 16, the third adhesive film layer 19 and the fourth adhesive film layer 24 are all modified polypropylene adhesive films obtained in Preparation Example 3, and the other steps are the same as in Example 2, wherein the gram weight of the reinforcement layer 2 is 145 g / m 2 . Comparative Example

[0078] Comparative Example 1

[0079] A dry process automobile interior ceiling substrate, which is different from Example 1 in that only a base layer 1 is provided, and no reinforcement layer 2 is provided. The other steps are the same as those of Example 1. The obtained sandwich structure automobile interior ceiling substrate has a gram weight of 680 g / m 2 .

[0080] Performance testing

[0081] The following relevant performance test tests were performed on the dry process automobile interior ceiling substrates obtained in Examples 1-7 and Comparative Example 1, respectively. Each group of tests was performed 3 times, and the average value of the 3 test results was taken as the final result. The experimental results are recorded in Table 1.

[0082] 1. Weigh the weight of the dry process automobile interior ceiling substrate obtained in Examples 1-7 and Comparative Example 1 respectively and calculate the gram weight.

[0083] 2. Bending properties: With reference to the relevant standards and regulations of GB / T 1449 "Test method for bending properties of fiber reinforced plastics", the bending strength and bending modulus of the dry process automobile interior ceiling substrate obtained in Examples 1-7 and Comparative Example 1 were tested.

[0084] 3. Odor: Referring to the standards and regulations of PV3900, the odor levels of the dry process automotive interior ceiling substrates obtained in Examples 1-7 and Comparative Example 1 were tested.

[0085] Table 1

[0086]

[0087] According to the performance test results in Table 1, it can be seen that the weight range of the dry process automotive interior ceiling substrate of the present application is 740-760 g / m 2, the odor is low, compared with the existing modular automotive interior ceiling sandwich substrate ≥1000g / m 2 The gram weight significantly reduces the weight of the car roof material, further realizes the lightweight design and production of automobile interior materials, ensures that the automobile interior materials maintain low odor, helps to achieve the goal of energy conservation and carbon reduction, and meets the modern automobile industry's multiple demands for production efficiency, environmental protection and lightweight.

[0088] In addition, a dry process automobile interior ceiling substrate of the present application has excellent compression resistance and bending performance, which helps to ensure that the automobile ceiling has sufficient rigidity and can meet the assembly requirements of any one or more secondary parts such as lamp brackets, lamps, wiring harnesses, anti-collision energy absorption blocks or energy absorption brackets, sun visors, handles, air-conditioning ducts, etc. on the automobile ceiling, thereby achieving the modular supply needs of lightweight automobile ceilings while ensuring that the automobile ceiling remains in good condition and is not damaged during turnover, storage, transportation and assembly.

[0089] According to the performance test results of Example 1 and Comparative Example 1, it can be seen that the automotive interior ceiling substrate of Comparative Example 1 is only suitable for preparing lightweight ceilings and ceilings without skylights. The present application sets a reinforcement layer in the front end area of ​​the base layer of the automotive interior ceiling substrate close to the front windshield to form a sandwich substrate, which effectively improves the rigidity of the automotive ceiling, ensures the assembly rigidity requirements of various automotive secondary parts, and ensures that the modular production of the automotive ceiling remains stable during the production, installation and turnover process, while also maximizing the lightweight design and production of the automotive interior ceiling substrate.

[0090] According to the performance test results of Examples 1-7, it can be seen that in this application, it is preferred to use a mixture of HDPE rubber powder and lamellar silicate minerals as the rubber powder material, and to use methyl methacrylate glycidyl and maleic anhydride melt-grafted modified polypropylene as the film material, which can effectively ensure the low odor and lightweight production of the automotive interior ceiling substrate while improving rigidity. This is because the use of HDPE rubber powder and lamellar silicate minerals as the rubber powder layer and the modified polypropylene film further improve the compatibility between the layers of the substrate composite material, improve the interface bonding ability, and significantly improve the mechanical properties between the layers. The use of methyl methacrylate glycidyl and maleic anhydride melt-grafted modified polypropylene as the film material is better than the use of maleic anhydride melt-grafted modified polypropylene as the film material.

[0091] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A dry process automobile interior ceiling substrate, comprising a base layer (1) and a reinforcement layer (2), characterized in that: The base layer (1) and the reinforcement layer (2) are both multi-layer structures; A sunroof reinforcement frame (3) is arranged on the base layer (1), and the reinforcement layer (2) is arranged inside the base layer (1) between a boundary of the sunroof reinforcement frame (3) close to one end of the automobile front and a boundary of the base material close to one end of the automobile front; The base layer (1) comprises, from bottom to top, a first fabric layer (11), a first glass fiber layer (12), a first rubber powder layer (13), a first rubber film layer (14), a PU foam layer (15), a second rubber film layer (16), a second glass fiber layer (17), a second rubber powder layer (18) and a third rubber film layer (19); The reinforcing layer (2) is arranged inside the base layer (1), and the reinforcing layer (2) comprises, from bottom to top, a second fabric layer (21), a third glass fiber layer (22), a third rubber powder layer (23) and a fourth adhesive film layer (24), the lower side of the second fabric layer (21) contacts the upper side of the first adhesive film layer (14), the upper side of the fourth adhesive film layer (24) contacts the lower side of the PU foam layer (15), and the gram weight of the reinforcing layer (2) is 140±20 g / m 2 In the reinforcing layer (2), the third glass fiber layer (22) has a gram weight of 40±3 g / m 2 The weight of the third rubber powder layer (23) is 40±4 g / m 2 The fourth adhesive film layer (24) has a gram weight of 30±5 g / m 2 ; The raw materials of the first rubber powder layer (13), the second rubber powder layer (18) and the third rubber powder layer (23) include rubber powder and lamellar silicate minerals in a mass ratio of 1:(0.13-0.22); The first adhesive film layer (14), the second adhesive film layer (16), the third adhesive film layer (19) and the fourth adhesive film layer (24) are all modified polypropylene adhesive films; The method for preparing the modified polypropylene film comprises the following steps: The polypropylene particles are uniformly mixed with maleic anhydride and glycidyl methacrylate in a mass ratio of 10:(1-1.5):(0.3-0.6), and then dicumyl peroxide is added for blending; the blend is added into a screw extruder, and a melt grafting reaction is carried out at 220-240° C. and a rotation speed of 65-75 r / min for 10-15 minutes, and a film is formed by extrusion and cooled and solidified to obtain the product.

2. The dry process automobile interior ceiling substrate according to claim 1, characterized in that: The raw materials of the first glass fiber layer (12), the second glass fiber layer (17) and the third glass fiber layer (22) are all TCR glass fibers.

3. A method for preparing a dry process automobile interior ceiling substrate according to any one of claims 1-2, characterized in that: The following steps are involved: S1: laying a non-woven fabric flat as the second fabric layer (21), cutting and spreading glass fibers on the second fabric layer (21), spreading a mixture of rubber powder and lamellar silicate minerals, laying a rubber film as a third glass fiber layer (22), a third rubber powder layer (23) and a fourth rubber film layer (24), heating, pressing and cooling at a preset temperature and conveying speed to obtain a reinforcement layer (2); S2: Laying a non-woven fabric flat as the first fabric layer (11), and sequentially cutting, spreading or laying glass fiber, a mixture of rubber powder and lamellar silicate minerals, a film, a reinforcing layer (2), a PU foam board, a film, glass fiber, a mixture of rubber powder and lamellar silicate minerals and a film on the first fabric layer (11) as the first glass fiber layer (12), the first rubber powder layer (13), the first film layer (14), the reinforcing layer (2), the PU foam layer (15), the second film layer (16), the second glass fiber layer (17), the second rubber powder layer (18) and the third film layer (19), respectively; heating, pressing and cooling at a preset temperature and conveying speed are performed to obtain a vehicle interior ceiling substrate.

Images