Automobile hallstand base material based on closed-cell PET (polyethylene terephthalate) foaming sheet

Abstract

The utility model provides an automobile hallstand base material based on a closed-cell PET (Polyethylene Terephthalate) foaming sheet, which solves the problems that the existing product is high in weight, not full in molding and low in adhesive force with a fabric. A closed-cell PET foaming sheet serves as a core layer, GMT layers are bonded to the upper surface and the lower surface of the closed-cell PET foaming sheet through bonding films, and non-woven fabric layers are bonded to the surfaces of the GMT layers through polypropylene double-layer composite films. The polypropylene double-layer composite film is a double-layer film formed by compounding a high-flowability polypropylene layer and a low-flowability polypropylene layer, and the low-flowability polypropylene layer in the polypropylene double-layer composite film is bonded with the non-woven fabric layer. The polypropylene double-layer composite film is compounded with the GMT layer, and infiltration of polypropylene and glass fibers is better, so that the strength of the GMT layer is higher. The closed-cell foam expands when being heated, so that a formed product is fuller, and the adhesive force between the low-fluidity polypropylene layer and the fabric is stronger.

Description

Technical Field

[0001] The utility model relates to an automobile coat rack, in particular to an automobile coat rack substrate based on a closed-cell PET foam sheet. Background Art

[0002] The design and manufacture of automotive interior accessories has always been one of the important areas of the automotive industry. As one of the common functional accessories in the car, the car coat rack provides passengers with a convenient storage space for items. Its design and material selection directly affect the utilization of the interior space, the overall weight of the vehicle, and the ride comfort. The car coat rack refers to the decorative panel covering the back of the rear seat backrest, the front of the rear windshield, the upper sheet metal of the rear side wall, and the visible area. It is designed to provide a durable and beautiful cover to cover the private space of the luggage compartment and facilitate the storage of lightweight items for passengers.

[0003] With the development of the automotive industry and the advancement of technology, the research and development and application of lightweight materials has become an important trend. PET foam composite materials have attracted much attention due to their light weight, durability, and good formability. However, the traditional lightweight GMT material single material structure is difficult to meet the requirements of automotive coat racks for structural strength and lightweight.

[0004] Therefore, in view of the problems existing in traditional automobile coat racks, it is necessary to propose a novel design and manufacturing method of automobile coat racks.

[0005] Chinese patent CN205553464U discloses a foam board with a composite cast PET layer, which includes a foam substrate and a mask covered thereon, the mask including a cast PET layer with a heat-sealing coating or a PS film layer on the surface after secondary stretching reinforcement. The crusted PET foam board produced by this process is costly and complicated.

[0006] Chinese patent CN110077076B discloses a polyester foam sandwich composite board that can be recycled as a whole and its closed-loop production process. The polyester foam sandwich composite board I is composed of a fiber-reinforced polyester resin composite layer, a polyester-based density gradient composite foam layer, and a fiber-reinforced polyester resin composite layer from bottom to top. The upper and lower layers of the polyester-based density gradient composite foam layer are high-density polyester foam composite boards, and the middle layer is a low-density polyester foam composite board. The polyester foam sandwich composite boards I are bonded by hot-melt bonding of the body or by hot-melt adhesive films of polyester or modified polyester. The upper and lower foam composite layers of this product need to be bonded separately, and hot-melt adhesive films need to be added between the surface layer and the foam. The product is an open-cell structure, and the production process is complicated.

[0007] Car coat racks are usually made by heating the base material of the car coat rack and bonding the layers that make up the base material of the car coat rack according to the interior requirements of different models. The core of lightweighting of car coat racks is lightweighting of the base material of the car coat rack. How to reduce the weight per unit thickness per unit area of ​​the base material of the car coat rack while maintaining its environmental protection and load-bearing requirements is a difficult problem. Summary of the invention

[0008] The utility model aims to provide a car coat rack substrate based on a closed-cell PET foam sheet, which solves the problems of the existing product having high weight, incomplete molding and low adhesion to fabrics.

[0009] To achieve the above purpose, the technical solution of the utility model is as follows:

[0010] The automobile coat rack substrate based on closed-cell PET foam sheet has the closed-cell PET foam sheet as the core layer, the upper and lower surfaces of the closed-cell PET foam sheet are bonded with GMT layers by adhesive films, and the surface of the GMT layer is bonded with a non-woven fabric layer by a polypropylene double-layer composite film; the polypropylene double-layer composite film is a double-layer film formed by a high-fluidity polypropylene layer and a low-fluidity polypropylene layer, the high-fluidity polypropylene refers to a polypropylene with a melt index of 100-1500g / 10min under the conditions of a temperature of 230°C and a load of 2.16kg, and the low-fluidity polypropylene refers to a polypropylene with a melt index of 1-20g / 10min under the conditions of a temperature of 230°C and a load of 2.16kg; the low-fluidity polypropylene layer in the polypropylene double-layer composite film is bonded to the non-woven fabric layer.

[0011] The above-mentioned car coat rack substrate, polypropylene double-layer composite film is produced by Hangzhou Zhihe New Materials Co., Ltd., model X24, gram weight 100g / m 2 The melt index of high-fluidity polypropylene is 740-760g / 10min, and the melt index of low-fluidity polypropylene is 8-12g / 10min.

[0012] The GMT layer of the above-mentioned automobile coat rack substrate is a mixture of chopped glass fiber and chopped polypropylene in a mass ratio of 40-60:40-60, and is carded, laid, and needled into a 220-280g / m 2 Lightweight GMT layer.

[0013] The above-mentioned automobile coat rack substrate, the bottom layer of needle-punched non-woven fabric is 70-90g / m 2 , top layer of needle punched nonwoven fabric 140-160g / m 2 .

[0014] The closed-cell PET foam sheet of the above-mentioned automobile coat rack substrate is a double-sided skinned PET foam sheet with a density of 100-120kg / m 3 , thickness 1-4mm.

[0015] Beneficial effects of the utility model:

[0016] In the solution of the utility model, due to the use of closed-cell PET foamed sheet (closed-cell foam) with a self-skinning closed-cell structure, the base material of the automobile coat rack can not only be hot-pressed according to traditional process equipment, but the closed-cell foam will expand when heated, so that the molded product is fuller, the molding pressure is greater, and the adhesion between the low-fluidity polypropylene layer and the fabric is stronger. The manufactured automobile coat rack is not only light in weight and high in strength, but also takes advantage of the heat insulation and sound insulation properties of the PET foam.

[0017] Closed-cell PET foam sheet belongs to the existing technology. Using self-skinned closed-cell PET foam sheet to replace traditional PET cut foam board not only has high environmental strength, but also reduces foam welding, cutting and other processes in the production process, no dust pollution, and low production cost; and the self-skinned closed-cell PET foam sheet has excellent heat insulation and sound insulation properties, and at the same time, it expands when heated during molding, making the product full and highly bonded to the fabric.

[0018] GMT is glass fiber thermoplastic prepreg, which is a semi-finished sheet made of glass fiber and thermoplastic plastic. It can be softened by heating, then placed in a press, pressed and cooled to make various products. According to the resin matrix material used, GMT has two types, namely polypropylene-based GMT and thermoplastic polyester-based PET. Most GMTs are glass fiber reinforced polypropylene.

[0019] The use of a double-layer polypropylene composite film can not only play a reinforcing effect, but also prevent the non-woven fabric layer from leaking through. If a double-layer polypropylene composite film is not used, and only a film formed by a layer of high-fluidity polypropylene is used, the high-fluidity polypropylene will penetrate into the non-woven fabric layer in direct contact with the high-fluidity polypropylene, causing the product to leak through. If only a film formed by a layer of low-fluidity polypropylene is used, although there will be no leakage, it will not have a reinforcing effect. The use of a high-low fluidity polypropylene double-layer composite film and a GMT layer will allow better penetration of polypropylene and glass fiber, thereby making the GMT layer stronger.

[0020] The utility model adopts closed-cell PET foam sheet, GMT layer, polypropylene double-layer composite film and the like for the design and manufacture of the automobile coat rack substrate, which significantly improves the structural strength, improves the sound insulation, heat insulation and other properties, and further improves the lightweight of the automobile.

[0021] The automobile coat rack substrate can be molded by conventional molding equipment and processes to obtain the automobile coat rack thermoplastic composite plate. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the substrate of the automobile coat rack based on the closed-cell PET foam sheet. DETAILED DESCRIPTION

[0023] Embodiment 1:

[0024] See also Figure 1 The substrate of the automobile coat rack based on the closed-cell PET foam sheet shown is, from top to bottom: a top needle-punched non-woven fabric layer 6, a polypropylene double-layer composite film 2, a GMT layer 3, an adhesive film 4, a closed-cell PET foam sheet 5, an adhesive film 4, a GMT layer 3, a polypropylene double-layer composite film 2, and a bottom needle-punched non-woven fabric layer 1.

[0025] The polypropylene double-layer composite film 2 is a double-layer composite film produced by Hangzhou Zhihe New Materials Co., Ltd. through co-extrusion equipment. It is composed of a high-fluidity polypropylene layer 2-2 and a low-fluidity polypropylene layer 2-1. The model is X24 and the gram weight is 100g / m 2 The melt index of high-fluidity polypropylene is 740-760 g / 10 min (230° C., 2.16 kg), and the melt index of low-fluidity polypropylene is 8-12 g / 10 min (230° C., 2.16 kg). The low-fluidity polypropylene layer 2-1 in the polypropylene double-layer composite film is bonded to the non-woven fabric layer.

[0026] GMT layer 3 is a polypropylene-based GMT layer with a glass fiber content of 28%-32%. It is produced by Changzhou Tianma Group Co., Ltd. and has a thickness of 0.5mm. It is made by mixing short-cut glass fiber and short-cut polypropylene in a mass ratio of 50:50, and then combing, laying, and needle punching to form a 250g / m 2 Lightweight GMT layer.

[0027] The weight of the bottom needle-punched nonwoven fabric layer 1 is 80 g / m 2 The top layer of needle-punched nonwoven fabric 6 has a gram weight of 150g / m 2 .

[0028] Closed-cell PET foam sheet 5 is a double-sided skinned PET foam sheet with a density of 100 kg / m 3 , thickness 3mm. Adhesive film 4 adopts conventional 30g / m 2 Adhesive film (film).

[0029] The preparation method of the automobile coat rack comprises the following steps: stacking a GMT layer and a polypropylene double-layer composite film, hot pressing at 190-210°C and then cooling to obtain a reinforced GMT felt; when stacking, the GMT layer is in contact with a high-fluidity polypropylene layer; stacking a bottom non-woven fabric, a reinforced GMT felt, an adhesive film, a closed-cell PET foam sheet, an adhesive film and a reinforced GMT felt in sequence, using a flat-plate thermal composite device with a heating plate temperature set at 210-230°C, hot pressing and then cooling to obtain a PET foam composite board; when stacking, the bottom non-woven fabric is in contact with a low-fluidity polypropylene layer in the reinforced GMT felt; heating the PET foam composite board to 180-220°C, laying a top non-woven fabric on the low-fluidity polypropylene layer in the PET foam composite board, hot pressing and then cooling to obtain an automobile coat rack with a thickness of about 5 mm.

[0030] The obtained automobile coat rack was tested, and the results are as follows.

[0031] The top nonwoven fabric and other parts of the car coat rack were subjected to peeling test according to method B in GB / T 8808-1988, with a sample width of 30 mm, a test speed of 200 ± 30 mm / min, and a longitudinal or transverse peeling force of ≥ 7.0 N.

[0032] Observing the appearance of the car coat rack, the product has a full shape, clear outline, no wrinkles, and no glue penetration.

[0033] The results of the 3-point bending test on the car coat rack are as follows:

[0034] Sample weight: 1300g

[0035] Sample No. HJY-231107-01

[0036] Use standard GB / T1449-2005

[0037] Span 80mm

[0038] Test speed 5mm / min

[0039] Initial force 3N

[0040] Serial number Sample width Bending stress Flexural modulus Bending Strength Elasticity slope Bending strength mm N MPa MPa N / cm N*mm(force*width) 1 48.82 135.4229 649.4732 16.2211 31.7422 6611.345978 2 50.59 118.5672 527.328 13.4663 29.7241 5998.314648 3 50.37 124.4069 598.4495 14.0679 31.2734 6266.375553 4 51.44 130.5254 591.0752 14.9039 30.3264 6714.226576 5 50.83 125.2179 668.8308 14.3422 32.6218 6364.825857 6 48.94 121.9294 773.4126 14.896 33.0407 5967.224836 7 49.56 133.0705 754.6947 16.3443 34.6158 6594.97398 8 52.03 139.5256 727.615 15.6814 35.5713 7259.516968 9 52.16 152.4902 683.2023 17.0206 34.9998 7953.888832 10 49.89 133.7209 676.674 15.4681 34.219 6671.335701

[0041] Comparative Example: The closed-cell PET foam sheet in Example 1 was treated with 300 g / m 2 Glass fiber reinforced PP board (FRPP board) (thickness 3mm) is used instead, and polypropylene double-layer composite film 2 is used with a gram weight of 50g / m 2 The automobile coat rack product prepared by using a process and equipment similar to that of Example 1 is replaced by an ordinary hot-melt adhesive film, and its undulating parts are prone to wrinkles and are not full.

[0042] The utility model adopts closed-cell PET foam sheet and combines it with a specific sandwich structure design to ensure that the coat rack is lightweight while improving its strength and durability. The product is full and has no glue penetration. Such innovative design and manufacturing methods will help meet the modern automotive industry's demand for lightweight, high-strength, and durable interior accessories, and improve the overall performance of the car and user experience.

Claims

1. The automobile coat rack substrate based on closed-cell PET foam sheet is characterized by: The closed-cell PET foam sheet is used as the core layer, and a GMT layer is bonded to the upper and lower surfaces of the closed-cell PET foam sheet through an adhesive film, and a non-woven fabric layer is bonded to the surface of the GMT layer through a polypropylene double-layer composite film; the polypropylene double-layer composite film is a double-layer film formed by compounding a high-fluidity polypropylene layer and a low-fluidity polypropylene layer, the high-fluidity polypropylene refers to a polypropylene with a melt index of 100-1500g / 10min under the conditions of a temperature of 230°C and a load of 2.16kg, and the low-fluidity polypropylene refers to a polypropylene with a melt index of 1-20g / 10min under the conditions of a temperature of 230°C and a load of 2.16kg; the low-fluidity polypropylene layer in the polypropylene double-layer composite film is bonded to the non-woven fabric layer.

2. The automobile coat rack substrate as claimed in claim 1, characterized in that: polypropylene The double-layer composite film is produced by Hangzhou Zhihe New Materials Co., Ltd., model X24, weight 100g / m 2 The melt index of high-fluidity polypropylene is 740-760g / 10min, and the melt index of low-fluidity polypropylene is 8-12g / 10min.

3. The automobile coat rack substrate as claimed in claim 2, characterized in that: The bottom layer of needle-punched nonwoven fabric is 70-90g / m 2 , top layer of needle punched nonwoven fabric 140-160g / m 2 .

4. The automobile coat rack substrate as claimed in claim 2, characterized in that: Closed-cell PET foam sheet is a double-sided skinned PET foam sheet with a density of 100-120kg / m 3 , thickness 1-4mm.

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