Composite material for automobile roof and method for manufacturing the same

Abstract

This invention provides a composite material for automotive roofs and its preparation method. The composite material comprises, in sequence, a decorative surface layer, a sound insulation layer, a first substrate layer, a core material layer, a second substrate layer, a breathable membrane layer, and a non-woven fabric layer; the first and second substrate layers each independently include 1-3 layers of adhesive-coated fiberglass material; the core material layer is prepared from PP foam. The composite material provided by this invention, when installed on the roof of a car, possesses high strength while also providing structural support, sound and heat insulation, and aesthetic appeal; furthermore, the preparation process eliminates the accumulation of semi-finished products, reducing the number of defective products due to insufficient strength and improving manufacturing costs; and no harmful substances are generated during the preparation process, meeting environmental protection requirements.

Description

Technical Field

[0001] This invention belongs to the field of automotive interior parts technology, and relates to a composite material, specifically a composite material for automotive headliners and its preparation method. Background Technology

[0002] The car roof is an important component of the automotive interior. Installed on the roof of the vehicle, it not only needs to be aesthetically pleasing but also provides structural support and safety protection for passengers during vehicle movement and collisions. With the development of the automotive industry, the requirements for the strength, rigidity, sound insulation, and heat insulation performance of car roofs are becoming increasingly stringent. Currently, the strength performance of car roofs often remains a bottleneck restricting their development.

[0003] Existing car roofs are typically made using a single layer of fiberglass or a common composite structure: CN 102423933A discloses a method for producing polyurethane composite panels for automotive roofs. The production method includes the following steps: 1) Laying non-woven fabric flat on the conveyor belt of a laminating machine, and then sequentially placing a first ethylene-propylene copolymer film, hot melt adhesive powder, glass fiber, and a second ethylene-propylene copolymer film on it. The laminating machine is then hot-pressed, cooled, and wound up to obtain the bottom layer of the polyurethane composite panel; 2) From bottom to top, a third ethylene-propylene copolymer film, glass fiber, and a fourth ethylene-propylene copolymer film are sequentially placed. The laminating machine is then hot-pressed, cooled, and wound up to obtain the top layer of the polyurethane composite panel; 3) The top layer, PU board, and bottom layer are placed sequentially from top to bottom. Using the thickness H of the composite top layer, PU board, and bottom layer as a reference, the gap between the pressure bars is adjusted to H±0.3. The laminating machine is then hot-pressed, cooled, and the polyurethane composite panel is obtained. CN 102795087A discloses a method for producing an automobile roof, the method comprising: a material baking step, a pressing and molding step, a cutting step, a material placement and positioning step, a baking and softening step, and an edge wrapping step; wherein the base material of the automobile roof is a polyurethane foam board with composite glass fiber, and a hot melt film layer of 30~60g / m2 is present on the upper surface of the polyurethane foam board. CN 103538329A discloses a method for producing a polyurethane multilayer composite panel for automotive roofs, comprising the following steps: 1) obtaining a perforated hot melt adhesive film for nonwoven fabric and a perforated hot melt adhesive film for PU through three-layer co-extrusion blown film; 2) sequentially arranging nonwoven fabric, perforated hot melt adhesive film for nonwoven fabric, fiberglass cloth or chopped glass fiber, and perforated hot melt adhesive film for PU on the conveyor belt of the composite production line from bottom to top, then placing a rigid polyurethane foam board, and then sequentially arranging a perforated hot melt adhesive film for PU, fiberglass cloth or chopped glass fiber, and PE film on the rigid polyurethane foam board from bottom to top, then conveying it to an infrared heating zone for preheating, and then entering a rolling process for hot pressing composite to obtain a polyurethane multilayer composite panel.

[0004] The automotive roof material provided by the above patent has the following main problems: 1. Insufficient product strength, which is prone to deformation and cracking during long-term use; 2. Poor impact resistance, which makes it difficult to effectively protect passengers in special circumstances such as collisions; 3. A large number of defective products are easily generated during the production process due to insufficient structural stability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a composite material for automotive roofs and its preparation method. The composite material provided by this invention, when installed on the roof of a vehicle, effectively ensures the roof's sound and heat insulation performance, and also possesses excellent properties such as high strength, good rigidity, and resistance to deformation or breakage.

[0006] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a composite material for automobile roofs, the composite material comprising a decorative surface layer, a sound insulation layer, a first substrate layer, a core material layer, a second substrate layer, a breathable membrane layer, and a non-woven fabric layer arranged in sequence. The first substrate layer and the second substrate layer each independently include 1 to 3 layers of adhesive fiberglass material, for example, 1, 2 or 3 layers.

[0007] The core material layer is made of PP foam material.

[0008] The composite material described in this invention is installed on the roof of a car as a canopy, which not only has high strength performance, but also has structural support, sound absorption and heat insulation and aesthetic functions. More specifically, the first and second substrate layers mainly serve as adhesives and sound absorbers; the core layer is mainly used to enhance the rigidity and sound absorption of the composite material for the automotive roof.

[0009] As a preferred embodiment of the present invention, the decorative surface layer includes an r-PET composite surface layer and / or a needle-punched nonwoven surface layer.

[0010] Preferably, the sound insulation layer includes a sound insulation cotton layer.

[0011] Preferably, the breathable membrane layer includes a PP breathable membrane layer and / or a PE breathable membrane layer.

[0012] Preferably, the thickness of the core material layer is 1 to 5 mm, for example, it can be 1 mm, 2 mm, 3 mm, 4 mm or 5 mm, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0013] In this invention, the core material layer is located in the middle of the composite material. When its thickness is too thick, although it will improve sound absorption and rigidity, it will significantly increase the manufacturing cost and is not conducive to industrial production; when its thickness is too thin, it will reduce sound absorption and rigidity.

[0014] As a preferred embodiment of the present invention, the adhesive-coated fiberglass material layer is obtained by sequentially applying double-sided adhesive and heat treatment to the fiberglass material.

[0015] Preferably, the distance between the upper and lower rollers of the roller glue machine used for double-sided roller glue rolling is independently 0.2~0.6mm, for example, it can be 0.2mm, 0.3mm, 0.4mm, 0.5mm or 0.6mm, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0016] Preferably, the roller motor frequency of the roller glue machine used for double-sided gluing is 30~50Hz, for example, it can be 30Hz, 34Hz, 38Hz, 42Hz, 46Hz or 50Hz, but is not limited to the listed values. Other values ​​not listed within the value range are also applicable.

[0017] Preferably, the adhesive used for the double-sided roll coating includes a PET adhesive.

[0018] The PET adhesive described in this invention is a high-strength adhesive; furthermore, the adhesive used for double-sided roll coating described in this invention is not limited to PET adhesive, as long as it can achieve double-sided roll coating of the glass fiber material.

[0019] Preferably, the amount of adhesive applied to the upper and lower surfaces of the glass fiber material is independently 50~100g / m². 2 For example, it could be 50g / m 2 60g / m 2 70g / m 2 80g / m 2 90g / m 2 Or 100g / m 2 This applies to, but is not limited to, the listed values; other unlisted values ​​within the range are also applicable.

[0020] In this invention, double-sided adhesive application to the fiberglass material not only enhances its adhesiveness but also improves its rigidity. Excessive adhesive application to the upper and lower surfaces of the fiberglass material can lead to surface pitting and unevenness, while insufficient adhesive application can result in insufficient rigidity or material delamination.

[0021] Preferably, the temperature of the heat treatment is 50~60℃, for example, it can be 50℃, 52℃, 54℃, 56℃, 58℃ or 60℃, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0022] This invention can soften glass fiber materials through heat treatment, thereby achieving reshaping; if the temperature of the heat treatment is too high, it will cause burns on the product surface, and if the temperature is too low, it will cause the product to fail to form.

[0023] In a second aspect, the present invention provides a method for preparing a composite material for automotive roofs as described in the first aspect, the method comprising the following steps: (1) Pre-treat the PP foam material, and then lay the decorative surface layer, sound-absorbing layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer in sequence. Then press and cool to solidify to obtain semi-finished material. (2) Cut the semi-finished material obtained in step (1) to obtain the composite material for automobile roof.

[0024] As a preferred technical solution of the present invention, the pretreatment in step (1) includes preheating and softening treatment.

[0025] Preferably, the temperature of the preheating and softening treatment is 80~100℃, for example, it can be 80℃, 84℃, 88℃, 92℃, 96℃ or 100℃, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0026] Preferably, the preheating and softening treatment time is 20~30s, for example, it can be 20s, 22s, 24s, 26s, 28s or 30s, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0027] As a preferred technical solution of the present invention, the upper mold temperature for pressing in step (1) is 130~140℃, for example, it can be 130℃, 132℃, 134℃, 136℃, 138℃ or 140℃, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0028] Preferably, the lower mold temperature for pressing in step (1) is 145~155℃, for example, it can be 145℃, 147℃, 149℃, 151℃, 153℃ or 155℃, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0029] The selection of upper and lower mold temperatures during the compression molding process described in this invention affects the curing degree, interfacial bonding force, and mechanical properties of the composite material. If the temperature during the compression molding process does not match the material selection of the composite material, it is very easy to cause warping, delamination, and pore sealing defects in the composite material. More specifically, if the temperature during the compression molding process is too high, it will cause the loss of some material properties (such as tensile strength and carbonization) and surface burns, while if the temperature is too low, it will cause the product to fail to form.

[0030] Preferably, the pressing pressure in step (1) is 8~18MPa, for example, it can be 8MPa, 10MPa, 12MPa, 14MPa, 16MPa or 18MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0031] Preferably, the pressing time in step (1) is 60~120s, for example, it can be 60s, 70s, 80s, 90s, 100s, 110s or 120s, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0032] As a preferred technical solution of the present invention, the cooling and shaping in step (1) includes vacuum adsorption cooling and shaping.

[0033] Preferably, the vacuum degree of the vacuum adsorption cooling and shaping is 0.4~0.8Mbar, for example, it can be 0.4Mbar, 0.5Mbar, 0.6Mbar, 0.7Mbar or 0.8Mbar, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0034] Preferably, the vacuum adsorption cooling and shaping time is ≥40s, for example, it can be 40s, 42s, 44s, 46s, 48s or 50s, etc., but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0035] As a preferred technical solution of the present invention, the cutting process in step (2) includes water jet cutting.

[0036] Preferably, the water pressure for water jet cutting is 45,000 to 55,000 psi, for example, 45,000 psi, 47,000 spi, 49,000 spi, 51,000 psi, 53,000 psi or 55,000 psi, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0037] Preferably, the air pressure for water jet cutting is 0.5~0.9MPa, for example, it can be 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa or 0.9MPa, but is not limited to the listed values. Other unlisted values ​​within the range are also applicable.

[0038] Preferably, the waterjet cutting process also includes an inspection process, specifically inspecting whether the surface of the composite material is flat, whether there are defects such as damage, cracks, wrinkles, unevenness, bubbles, glue residue, and uneven color, and whether the impact strength meets industry standards.

[0039] As a preferred embodiment of the present invention, the method for preparing the composite material for automobile roofs as described in the first aspect, provided by the second aspect of the present invention, includes the following steps: (1) The PP foam material is preheated and softened for 20-30 seconds at 80-100℃, and then the decorative surface layer, sound-absorbing layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer are laid in sequence. Then, the material is pressed and molded and vacuum adsorption cooling is used to obtain the semi-finished material. The upper mold temperature for the pressing process is 130~140℃, the lower mold temperature is 145~155℃, the pressure is 8~18MPa, and the time is 60~120s. The vacuum degree of the vacuum adsorption cooling and shaping is 0.4~0.8Mbar, and the time is ≥40s; (2) The semi-finished material obtained in step (1) is water-jet cut to obtain the composite material for the car roof; The water pressure for water jet cutting is 45,000~55,000 psi, and the air pressure is 0.5~0.9 MPa.

[0040] The numerical range described in this invention includes not only the point values ​​listed above, but also any point values ​​within the numerical ranges not listed above. Due to space limitations and for the sake of brevity, this invention will not exhaustively list all the specific point values ​​included in the range.

[0041] Compared with the prior art, the present invention has the following beneficial effects: (1) The composite material for automobile roof provided by the present invention has high strength, which can meet the high strength performance requirements of automobile roof assembly, and has excellent sound absorption and heat insulation performance. (2) The composite material for automobile roof provided by the present invention can further improve the strength and rigidity of the material by setting multiple layers of adhesive fiberglass material; making the composite material less prone to deformation and breakage; (3) The composite material for automobile roof provided by the present invention does not have the accumulation of semi-finished products during the preparation process, which reduces the number of defective products due to insufficient strength and solves the manufacturing cost problem; and no harmful substances are generated during the preparation process, which meets the environmental protection requirements. Detailed Implementation

[0042] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0043] The PP foaming material described in the following examples and comparative examples was purchased from Wuxi Jixing Automotive Acoustics Components Technology Co., Ltd.; the roller adhesive (PET adhesive) used for the double-sided roller coating was purchased from Zhangjiagang Heju Company; and the fiberglass material was purchased from Nanjing Tianming Company.

[0044] Example 1 This embodiment provides a composite material for automobile roofs, the composite material comprising a decorative surface layer, a sound-absorbing layer, a first substrate layer, a core material layer, a second substrate layer, a breathable membrane layer, and a non-woven fabric layer stacked sequentially; The first substrate layer and the second substrate layer each independently include three layers of adhesive-coated fiberglass material stacked together; The core material layer is made of PP foam material; The decorative surface layer is an r-PET composite surface layer; the sound-absorbing layer is a sound-absorbing cotton layer; the breathable membrane layer is a PP breathable membrane layer; the core material layer has a thickness of 3mm; The adhesive-coated fiberglass material layer is obtained by sequentially applying double-sided adhesive and heat treatment to the fiberglass material; The roller motor of the double-sided roller coating machine has a frequency of 30Hz, and the distance between the upper and lower rollers is 0.4mm. The roller coating used includes PET adhesive. The amount of adhesive applied to the upper and lower surfaces of the glass fiber material is 70g / m², respectively. 2 ; The temperature for the heat treatment is 50°C.

[0045] The preparation method of the composite material for automobile roof described in this embodiment includes the following steps: (1) The PP foam material is preheated and softened for 20 seconds at 80℃, and then the decorative surface layer, sound-absorbing layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer are laid in sequence. Then, the material is pressed and molded and vacuum adsorption cooling is performed to obtain the semi-finished material. The upper mold temperature for the pressing process is 130°C, the lower mold temperature is 145°C, the pressure is 10MPa, and the time is 80s. The vacuum degree of the vacuum adsorption cooling and shaping process is 0.5 Mbar, and the time is 50 s; (2) The semi-finished material obtained in step (1) is water-jet cut to obtain a composite material for automobile roof with specifications of L1800×W1200mm, which can be used as the roof of GAC Toyota automobiles. The water jet cutting pressure is 45,000 psi and the air pressure is 0.6 MPa.

[0046] Example 2 This embodiment provides a composite material for automobile roofs, the composite material comprising a decorative surface layer, a sound-absorbing layer, a first substrate layer, a core material layer, a second substrate layer, a breathable membrane layer, and a non-woven fabric layer stacked sequentially; The first substrate layer and the second substrate layer each independently include two laminated layers of adhesive-coated fiberglass material; The core material layer is made of PP foam material; The decorative surface layer is a needle-punched nonwoven surface layer; the sound-absorbing layer is a sound-absorbing cotton layer; the breathable membrane layer is a PE breathable membrane layer; the core material layer has a thickness of 5mm; The adhesive-coated fiberglass material layer is obtained by sequentially applying double-sided adhesive and heat treatment to the fiberglass material; The roller motor of the double-sided roller coating machine has a frequency of 40Hz, and the distance between the upper and lower rollers is 0.5mm. The adhesive used is PET adhesive. The amount of adhesive applied to the upper and lower surfaces of the glass fiber material is 50g / m², respectively. 2 ; The temperature for the heat treatment is 55°C.

[0047] The preparation method of the composite material for automobile roof described in this embodiment includes the following steps: (1) The PP foam material is preheated and softened for 25 seconds at 90℃, and then the decorative surface layer, sound-absorbing layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer are laid in sequence. Then, the material is pressed and molded and vacuum adsorption cooling is performed to obtain the semi-finished material. The upper mold temperature for the pressing process is 135°C, the lower mold temperature is 150°C, the pressure is 12MPa, and the time is 100s. The vacuum degree of the vacuum adsorption cooling and shaping process is 0.6 Mbar, and the time is 60 s; (2) The semi-finished material obtained in step (1) is water-jet cut to obtain a composite material for car roof with specifications of L1900×W1300mm; The water jet cutting pressure is 50,000 psi and the air pressure is 0.7 MPa.

[0048] Example 3 This embodiment provides a composite material for automobile roofs, the composite material comprising a decorative surface layer, a sound-absorbing layer, a first substrate layer, a core material layer, a second substrate layer, a breathable membrane layer, and a non-woven fabric layer stacked sequentially; The first substrate layer and the second substrate layer each independently include a laminated layer of adhesive-coated fiberglass material; The core material layer is made of PP foam material; The decorative surface layer is a needle-punched nonwoven surface layer; the sound-absorbing layer is a sound-absorbing cotton layer; the breathable membrane layer is a PP breathable membrane layer; the core material layer has a thickness of 5mm; The adhesive-coated fiberglass material layer is obtained by sequentially applying double-sided adhesive and heat treatment to the fiberglass material; The roller motor of the double-sided roller coating machine has a frequency of 50Hz, and the distance between the upper and lower rollers is 0.6mm. The roller coating used includes PET adhesive. The amount of adhesive applied to the upper and lower surfaces of the glass fiber material is 100g / m², respectively. 2 ; The temperature for the heat treatment is 60°C.

[0049] The preparation method of the composite material for automobile roof described in this embodiment includes the following steps: (1) The PP foam material is preheated and softened for 30 seconds at 100℃, and then the decorative surface layer, sound-absorbing layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer are laid in sequence. Then, the material is pressed and molded and vacuum adsorption cooling is performed to obtain the semi-finished material. The upper mold temperature for the pressing process is 140°C, the lower mold temperature is 155°C, the pressure is 15MPa, and the time is 120s. The vacuum degree of the vacuum adsorption cooling and shaping process is 0.8 Mbar, and the time is 50 s; (2) The semi-finished material obtained in step (1) is water-jet cut to obtain the composite material for the car roof; The water jet cutting pressure is 55,000 psi and the air pressure is 0.5 MPa.

[0050] Example 4 This embodiment provides a composite material for automotive roofs, which differs from Embodiment 1 only in that: In this embodiment, the amount of adhesive applied to the upper and lower surfaces of the glass fiber material in the double-sided roll adhesive process is independently adjusted to 40g / m². 2 .

[0051] The preparation method of the composite material for automobile roof described in this embodiment is the same as that in Embodiment 1.

[0052] Example 5 This embodiment provides a composite material for automotive roofs, which differs from Embodiment 1 only in that: In this embodiment, the amount of adhesive applied to the upper and lower surfaces of the glass fiber material in the double-sided roll adhesive process is independently adjusted to 120g / m². 2 .

[0053] The preparation method of the composite material for automobile roof described in this embodiment is the same as that in Embodiment 1.

[0054] Example 6 This embodiment provides a composite material for automotive roofs, which differs from Embodiment 1 only in that: In this embodiment, the thickness of the core material layer is adjusted to 0.5 mm.

[0055] The preparation method of the composite material for automobile roof described in this embodiment is the same as that in Embodiment 1.

[0056] Example 7 This embodiment provides a composite material for automotive roofs, which differs from Embodiment 1 only in that: In this embodiment, the thickness of the core material layer is adjusted to 6mm.

[0057] The preparation method of the composite material for automobile roof described in this embodiment is the same as that in Embodiment 1.

[0058] Example 8 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: In this embodiment, the temperature of the preheating and softening treatment in step (1) is adjusted to 60°C.

[0059] Example 9 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: In this embodiment, the temperature of the preheating and softening treatment in step (1) is adjusted to 120°C.

[0060] Example 10 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: This embodiment omits the preheating and softening process of the PP foam material.

[0061] Example 11 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: In this embodiment, the temperature of the upper mold used for pressing in step (1) is adjusted to 125°C and the temperature of the lower mold is adjusted to 140°C.

[0062] Example 12 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: In this embodiment, the temperature of the upper mold used for pressing in step (1) is adjusted to 145°C and the temperature of the lower mold is adjusted to 160°C.

[0063] Example 13 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: In this embodiment, the pressure for pressing in step (1) is adjusted to 6 MPa.

[0064] Example 14 This embodiment provides a composite material for automotive roofs, which has the same structure as that in Embodiment 1; the only difference between the preparation method of the composite material for automotive roofs and that in Embodiment 1 is: In this embodiment, the pressure for pressing in step (1) is adjusted to 20 MPa.

[0065] Comparative Example 1 This comparative example provides a composite material for automotive roofs, which differs from Example 1 only in that: In this comparative example, both the first substrate layer and the second substrate layer are adjusted to be glass fiber material layers of equal number, that is, the glass fiber material is not subjected to double-sided roll adhesive treatment.

[0066] The preparation method of the composite material for automobile roof described in this comparative example is the same as that in Example 1.

[0067] Comparative Example 2 This comparative example provides a composite material for automotive roofs, which differs from Example 1 only in that: This comparative example omits the inclusion of the sound-absorbing layer.

[0068] The preparation method of the composite material for automobile roof described in this comparative example is the same as that in Example 1.

[0069] Comparative Example 3 This comparative example provides a composite material for automotive roofs, which differs from Example 1 only in that: This comparative example omits the core material layer.

[0070] Comparative Example 4 This comparative example provides a composite material for automotive roofs, which differs from Example 1 only in that: In this comparative example, the raw material for preparing the core layer is adjusted to PS foam material.

[0071] Performance testing: The composite materials for automotive roofs provided in the above embodiments and comparative examples were tested for strength, thermal insulation performance, and sound absorption performance. The results are shown in Table 1. The strength test includes: bending strength and overall rigidity test of the roof; and the width of the composite material used for the car roof in the bending strength (rigidity strength) test is 50mm. The sound absorption performance test includes: conducting sound absorption tests using the methods provided in GB / T 18696.1-2004; The thermal insulation performance test includes testing the thermal conductivity of the composite material using the method provided in GB / T 10294.

[0072] Table 1 Note: In Table 1, " / " indicates that the product could not be formed and no specific data results could be obtained.

[0073] According to Table 1, the following points can be observed: (1) Comprehensive analysis of Examples 1-3 shows that the composite material for automobile roof provided by the present invention has high strength, which can meet the high strength performance requirements of automobile roof assembly, and has excellent sound absorption and heat insulation performance. (2) Comprehensive analysis of Examples 1, 4-5 and Comparative Example 1 shows that if the amount of adhesive applied to the adhesive fiberglass material layer is too low, the roof will be too rigid or the material will be delaminated. If the amount of adhesive applied is too high, the product surface will be pitted and uneven. In addition, omitting the roll bonding process for the fiberglass material layer will result in a reduction in product rigidity; (3) A comprehensive analysis of Implementation 1 and Examples 6-10 shows that the core material layer is the core material of the composite material; If the thickness of the core material layer is too low, the sound absorption performance will be reduced, but the rigidity will be high; if the thickness is too high, the cost will be high. If the preheating and softening temperature of the PP foam material is too high during the preparation process, some properties (such as tensile strength and carbonization) will be lost; if the temperature is too low, the product will not be able to be formed. If the pretreatment process is omitted, the product will not be able to be formed. (4) A comprehensive analysis of Examples 1 and 11-14 shows that the compression molding affects the curing effect and strength properties of the composite material; If the pressing temperature is too low, the product will not form properly. (5) A comprehensive analysis of Example 1 and Comparative Examples 2-4 shows that the structural composition or material selection of the composite material will affect the performance of the composite material; Omitting the sound-absorbing layer will reduce the product's sound absorption performance. Omitting the core material layer will reduce both the product's rigidity and sound absorption performance; changing the raw material for the core material layer to PS foam will also reduce both rigidity and sound absorption performance.

[0074] In summary, the composite material provided by this invention, when installed on the roof of a car as a canopy, possesses high strength while also providing structural support, sound absorption, heat insulation, and aesthetic appeal. Furthermore, the absence of semi-finished product accumulation during the manufacturing process reduces the number of defective products due to insufficient strength, thus reducing manufacturing costs. Moreover, no harmful substances are generated during the manufacturing process, meeting environmental protection requirements.

[0075] The applicant declares that the above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A composite material for automobile roofs, characterized in that, The composite material comprises a decorative surface layer, a sound insulation layer, a first substrate layer, a core material layer, a second substrate layer, a breathable membrane layer, and a non-woven fabric layer, which are stacked in sequence. The first substrate layer and the second substrate layer each independently include 1 to 3 layers of adhesive-coated fiberglass material; The core material layer is made of PP foam material.

2. The composite material for automobile roofs according to claim 1, characterized in that, The decorative surface layer includes an r-PET composite surface layer and / or a needle-punched nonwoven surface layer; Preferably, the sound insulation layer includes a sound insulation cotton layer; Preferably, the breathable membrane layer comprises a PP breathable membrane layer and / or a PE breathable membrane layer; Preferably, the thickness of the core material layer is 1~5mm.

3. The composite material for automotive roofs according to claim 1, characterized in that, The adhesive-coated fiberglass material layer is obtained by sequentially applying double-sided adhesive and heat treatment to the fiberglass material.

4. The composite material for automobile roofs according to claim 3, characterized in that, The distance between the upper and lower rollers of the roller glue machine used for double-sided roller glue is 0.2~0.6mm, respectively. Preferably, the roller motor frequency of the roller glue machine used for double-sided roller glue is 30~50Hz; Preferably, the adhesive used for the double-sided roll coating includes a PET adhesive; Preferably, the amount of adhesive applied to the upper and lower surfaces of the glass fiber material is independently 50~100g / m². 2 ; Preferably, the temperature of the heat treatment is 50~60℃.

5. A method for preparing a composite material for automotive roofs as described in any one of claims 1-4, characterized in that, The preparation method includes the following steps: (1) Pre-treat the PP foam material, and then lay the decorative surface layer, sound insulation layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer in sequence, and then press and cool to obtain semi-finished material. (2) Cut the semi-finished material obtained in step (1) to obtain the composite material for automobile roof.

6. The preparation method according to claim 5, characterized in that, The pretreatment in step (1) includes a preheating and softening process; Preferably, the temperature of the preheating and softening treatment is 80~100℃; Preferably, the preheating and softening treatment time is 20-30 seconds.

7. The preparation method according to claim 5 or 6, characterized in that, The temperature of the upper mold used for pressing in step (1) is 130~140℃; Preferably, the temperature of the lower die used for pressing in step (1) is 145~155℃; Preferably, the pressing pressure in step (1) is 8~18MPa; Preferably, the pressing time in step (1) is 60~120s.

8. The preparation method according to any one of claims 5-7, characterized in that, The cooling and shaping process in step (1) includes vacuum adsorption cooling and shaping; Preferably, the vacuum degree of the vacuum adsorption cooling and shaping is 0.4~0.8 Mbar; Preferably, the vacuum adsorption cooling and shaping time is ≥40s.

9. The preparation method according to any one of claims 5-8, characterized in that, The cutting process in step (2) includes waterjet cutting; Preferably, the water pressure for water jet cutting is 45,000 to 55,000 psi; Preferably, the air pressure for water jet cutting is 0.5~0.9MPa.

10. The preparation method according to any one of claims 5-9, characterized in that, The preparation method includes the following steps: (1) The PP foam material is preheated and softened for 20-30 seconds at 80-100℃, and then the decorative surface layer, sound insulation layer, first substrate layer, core material layer, second substrate layer, breathable membrane layer and non-woven fabric layer are laid in sequence. Then, the material is pressed and molded and vacuum adsorption cooling is performed to obtain the semi-finished material. The upper mold temperature for the pressing process is 130~140℃, the lower mold temperature is 145~155℃, the pressure is 8~18MPa, and the time is 60~120s. The vacuum degree of the vacuum adsorption cooling and shaping is 0.4~0.8Mbar, and the time is ≥40s; (2) The semi-finished material obtained in step (1) is water-jet cut to obtain the composite material for the car roof; The water pressure for water jet cutting is 45,000~55,000 psi, and the air pressure is 0.5~0.9 MPa.

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