Polyester sandwich composite material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of polymer material science, environment-friendly material preparation and composite material preparation, in particular to a polyester sandwich composite material as well as a preparation method and application thereof. Comprising an upper skin reinforcing layer, a core layer and a lower skin reinforcing layer, the components of the upper and lower surface reinforcing layers are polyester and glass fibers, and the core layer is polyethylene glycol terephthalate foam. According to the invention, the impact resistance and scratch resistance of the polyester sandwich composite material are improved; the use amount of an adhesive in the preparation process of the sandwich composite material is reduced, and the production cost and the pollution to the environment are reduced; the polyester material is recycled, and the environmental protection performance of the polyester material is improved.

Description

Technical Field

[0001] The invention relates to the fields of polymer material science, environmentally friendly material preparation and composite material preparation technology, and in particular to a polyester sandwich composite material and a preparation method and application thereof. Background Art

[0002] With the improvement of environmental awareness, people have higher and higher requirements for the environmental performance of materials. Traditional sandwich composite materials often require a large amount of adhesives for bonding, which not only increases the production cost, but also produces a large amount of harmful gases during the production process, causing pollution to the environment, and cannot be recycled. Therefore, the development of a low-carbon and environmentally friendly composite material has become a hot topic in current research. On the other hand, polyester foam materials are widely used in the preparation of various composite materials because of their good mechanical properties and chemical stability. At present, the surface reinforcement capacity of the full PET composite materials on the market is insufficient, and the surface of the general PET sandwich composite material uses a reinforcement layer of other materials, and the products are difficult to recycle, which to a certain extent limits its application.

[0003] For example, patent CN117698252A uses PP unidirectional tape and PET foam to compound, and the product is difficult to recycle. In addition, the existing technology often requires the use of a large amount of adhesive for bonding, which also increases production costs and causes environmental pollution. In summary, the technical problems of the existing technology are: 1) The surface of the polypropylene unidirectional tape is easily scratched, causing bad damage; 2) The amount of adhesive used in the preparation process of the polyester material is too high; 3) The surface of the material is bonded by glue, and the finished product is difficult to recycle. Summary of the invention

[0004] In order to solve the above problems, the present invention provides a polyester sandwich composite material and its preparation method and application, which solves the technical problems such as how to improve the impact resistance and scratch resistance of the polyester material without sacrificing the processing performance of the polyester material; how to reduce the amount of adhesive used in the preparation process of the polyester material, reduce production costs and pollution to the environment; how to achieve the recycling and reuse of the polyester material and improve its environmental performance.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a polyester sandwich composite material, comprising an upper skin reinforcement layer, a core layer and a lower skin reinforcement layer;

[0007] The upper epidermis reinforcement layer is composed of polyester and glass fiber, the mass ratio of the polyester to the glass fiber is 45:55, and the thickness is 0.7 to 2.5 mm;

[0008] The lower skin reinforcement layer is composed of polyester and glass fiber, the mass ratio of the polyester to the glass fiber is 45:55, and the thickness is 0.7 to 2.5 mm;

[0009] The core layer is polyethylene terephthalate foam with a density ranging from 100 to 300 mm and a thickness ranging from 4 to 20 mm.

[0010] Preferably, the thickness of the upper epidermis reinforcement layer is 1.4 mm, and the thickness of the lower epidermis reinforcement layer is 1.4 mm.

[0011] Preferably, the weight of the upper epidermis reinforcement layer is 1000-2000 g / m 2 The weight of the lower skin reinforcement layer is 1000-2000 g / m 2 .

[0012] Preferably, the polyester comprises polyethylene terephthalate and / or polyethylene terephthalate-1,4-cyclohexanedimethanol.

[0013] The present invention also provides a method for preparing the polyester sandwich composite material described in the above technical solution, comprising the following steps:

[0014] 1) preparing a polyester unidirectional tape layer by melt impregnation of the polyester and glass fiber, overlapping and hot pressing N single-layer polyester unidirectional tape layers to obtain an upper skin reinforcement layer and a lower skin reinforcement layer, N ≥ 2;

[0015] 2) The upper skin reinforcement layer, the lower skin reinforcement layer and the core layer obtained in step 1) are stacked in sequence, and thermally compounded to obtain a polyester sandwich composite material.

[0016] Preferably, the conditions for melt impregnation in step 1) include:

[0017] The polyester is output through a single screw extruder to obtain a polyester melt, and the equipment parameters are: power 20-25HZ, speed 10-12m / min, temperature 240-280°C;

[0018] The outputted polyester melt is impregnated with the continuously unwound glass fiber through a mold to obtain a polyester unidirectional tape layer. The cylinder pressure during mold pressing is 5 to 6.5 kg.

[0019] Preferably, the overlapping method in step 1) includes: overlapping in a manner of 0° / 90°, 0° / 90° / 0°, 0° / 90° / 0° / 90° or 0° / 90° / 90° / 0°;

[0020] The conditions of the hot pressing include: a temperature of 200 to 230° C., a pressure of 5 to 8 MPa, and a speed of 3 to 5 m / min.

[0021] Preferably, the conditions for the thermal compounding in step 2) include: a temperature of 200 to 230° C., a pressure of 8 MPa, and a speed of 1 to 3 m / min.

[0022] The present invention also provides the use of the polyester sandwich composite material described in the above technical solution in improving the impact resistance of the composite material.

[0023] The present invention also provides the use of the polyester sandwich composite material described in the above technical solution in improving the scratch resistance of the composite material.

[0024] Beneficial effects of the present invention:

[0025] Due to the advanced nature of the technical solution, it can be widely used in the fields of automobile manufacturing, building decoration, home appliance manufacturing, packaging materials, etc. First, the automobile manufacturing industry has a huge demand for lightweight, high-strength, and environmentally friendly materials. The polyester sandwich composite material of the present invention just meets these requirements and can be widely used in logistics vehicle compartment panels, RV floors or slide-out panels, automotive interior parts, bumpers, doors, battery housings, bottom guards, and other parts of new energy vehicles. Secondly, the field of building decoration also has a high demand for high-impact and easy-to-clean materials. The polyester sandwich composite material of the present invention has excellent weather resistance, scratch resistance, and high impact resistance, and can be widely used in decorative materials such as building sheets, floors, ceilings, and photovoltaic backboards. Thirdly, the home appliance manufacturing industry also has a high demand for durable, beautiful, and environmentally friendly materials. The polyester sandwich composite material of the present invention can be widely used in the outer shells and internal structures of home appliances such as refrigerators, washing machines, and air conditioners. Finally, the field of fitness materials also has a huge demand for lightweight, high-strength, and environmentally friendly materials. The polyester sandwich composite material of the present invention can be widely used in rackets, skis, and the like. In general, the polyester sandwich composite material of the present invention has broad market prospects and application value.

[0026] 1. Low carbon and environmental protection: The skin and the core layer of the present invention are bonded by hot pressing, without the need to use a large amount of adhesive for bonding, replacing the polyurethane glue adhesive and other adhesives in the prior art, thereby reducing production costs and avoiding the generation of a large amount of harmful gases in the production process, causing pollution to the environment, and meeting current environmental protection requirements.

[0027] 2. High impact resistance: The combination of polyester and continuous long glass fiber in the skin reinforcement layer of the present invention provides excellent impact resistance, while the middle core layer can absorb a part of the external impact energy, thereby improving the overall impact resistance of the composite material.

[0028] 3. Good scratch resistance: The polyester material of the surface of the present invention provides scratch resistance, so that the composite material has excellent scratch resistance.

[0029] 4. Possessing certain formability: The composite material of the present invention can be directly molded at a certain temperature; or molded and injection molded to form parts containing reinforced parts, and has certain formability, thereby expanding its application range.

[0030] In general, compared with the prior art, the present invention not only improves the impact resistance and scratch resistance of polyester materials, but also, while achieving this goal, the product can be recycled, is more environmentally friendly, and has higher practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0032] Figure 1 Schematic diagram of polyester sandwich composite material; upper skin reinforcement layer, PET foam, lower skin reinforcement layer. DETAILED DESCRIPTION

[0033] The present invention provides a polyester sandwich composite material, comprising an upper skin reinforcement layer, a core layer and a lower skin reinforcement layer; the upper skin reinforcement layer is composed of polyester and glass fiber, the mass ratio of the polyester and the glass fiber is 45:55, and the thickness is 0.7-2.5 mm; the lower skin reinforcement layer is composed of polyester and glass fiber, the mass ratio of the polyester and the glass fiber is 45:55, and the thickness is 0.7-2.5 mm; the core layer is polyethylene terephthalate foam, with a density range of 100-300 densities and a thickness of 4-20 mm. In the present invention, the thickness of the upper skin reinforcement layer is preferably 1.4 mm, and the thickness of the lower skin reinforcement layer is preferably 1.4 mm. In the present invention, the gram weight of the upper skin reinforcement layer is preferably 1000-2000 g / m 2 The weight of the lower skin reinforcement layer is preferably 1000-2000 g / m 2 In the present invention, the polyester preferably includes polyethylene terephthalate and / or polyethylene terephthalate-1,4-cyclohexanedimethanol. The present invention has no special limitation on the sources of the above components, and conventional commercially available ones can be used, such as glass fiber from Jushi Glass Fiber, brand 522.

[0034] The present invention also provides a method for preparing the polyester sandwich composite material described in the above technical solution, comprising the following steps:

[0035] 1) preparing a polyester unidirectional tape layer by melt impregnation of the polyester and glass fiber, overlapping and hot pressing N single-layer polyester unidirectional tape layers to obtain an upper skin reinforcement layer and a lower skin reinforcement layer, N ≥ 2;

[0036] 2) The upper skin reinforcement layer, the lower skin reinforcement layer and the core layer obtained in step 1) are stacked in sequence, and thermally compounded to obtain a polyester sandwich composite material.

[0037] In the present invention, the polyester and glass fiber are prepared by melt impregnation to obtain a polyester unidirectional tape layer, and N single-layer polyester unidirectional tape layers are overlapped and hot-pressed to obtain an upper skin reinforcement layer and a lower skin reinforcement layer. In the present invention, the melt impregnation conditions preferably include: the polyester is output through a single-screw extruder to obtain a polyester melt, and the equipment parameters are: power 20-25HZ, speed 10-12m / min, temperature 240-280°C;

[0038] The output polyester melt is impregnated with the continuously unwound glass fiber through a mold to obtain a polyester unidirectional tape layer, and the cylinder pressure during mold pressing is 5 to 6.5 kg. In the present invention, the overlapping method preferably includes: superimposing in accordance with 0° / 90°, 0° / 90° / 0°, 0° / 90° / 0° / 90° or 0° / 90° / 90° / 0°. In the present invention, the hot pressing conditions preferably include: a flat-plate laminating machine uses a Teflon belt to press the sheet layer, the pressing temperature is 200 to 230°C, the pressure is 5 to 8MPa, and the speed is 3 to 5m / min.

[0039] The present invention stacks the obtained upper skin reinforcement layer, lower skin reinforcement layer and core layer in sequence, and obtains a polyester sandwich composite material after thermal compounding. In the present invention, the thermal compounding conditions preferably include: temperature of 200-230°C, pressure of 8MPa, and speed of 1-3m / min.

[0040] The present invention also provides the use of the polyester sandwich composite material described in the above technical solution in improving the impact resistance of the composite material.

[0041] The present invention also provides the use of the polyester sandwich composite material described in the above technical solution in improving the scratch resistance of the composite material.

[0042] In order to further illustrate the present invention, the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0043] Example 1

[0044] The invention discloses a polyester sandwich composite material, comprising an upper skin reinforcement layer, a core layer and a lower skin reinforcement layer from top to bottom, wherein the upper skin reinforcement layer and the lower skin reinforcement layer are both polyester and glass fiber mixed layers, with a mass ratio of 45:55, a thickness of 1.4 mm, and a gram weight of 2000 g / m 2The polyester is polyethylene terephthalate (PET), and the glass fiber is Jushi Group's 522 glass fiber. The core layer is polyethylene terephthalate (PET) foam, with a density range of 200 densities and a thickness of 7.2 mm.

[0045] The preparation method of the low-carbon, environmentally friendly, high-impact and scratch-resistant polyester sandwich composite material is as follows:

[0046] Step 1: Prepare the epidermal reinforcement layer.

[0047] The polyester is output through a single screw extruder to obtain a polyester melt. The equipment parameters are: power 25HZ, speed 10m / min, temperature 280℃; the output polyester melt is impregnated with the continuously unwound glass fiber through a mold to obtain a polyester unidirectional tape layer. The cylinder pressure when the mold is pressed is 6.5kg to obtain a polyester unidirectional tape layer. Its thickness is 0.35mm and its gram weight is 500g / m 2 Four single-layer polyester unidirectional tape layers are overlapped and hot-pressed in the manner of 0° / 90° / 0° / 90° to form a 1.4mm thick skin reinforcement layer with a gram weight of 2000g / m 2 The flat laminating machine uses Teflon belt to press the sheets, the pressing temperature is 200-230°C, the pressure is 5-8MPa, and the speed is 3m / min.

[0048] Step 2: Prepare the core layer. PET foam is selected as the middle core layer, with a density of 200 d and a thickness of 7.2 mm.

[0049] Step 3: Composite molding. 2 Upper skin reinforcement layer, PET foam, 2000g / m 2 After the lower skin reinforcement layer is laid in order, it is put into the flat-plate laminating machine for lamination. The Teflon belt of the flat-plate laminating machine is the 9580A model of Shanghai Kaiyao Industrial Belt Co., Ltd., and the pressing temperature is set at 230℃, the pressure is set at 8Mpa, and the speed is 1m / min.

[0050] Step 4: Cooling and shaping to obtain the product. The composite material is cooled and shaped in the cooling area of ​​the flat-plate composite machine, and the outlet temperature is lower than 30°C to obtain a composite plate.

[0051] The product of Example 1 can be used for building formwork.

[0052] The building formwork replaces bamboo plywood, wood board, etc., and is used as a pouring formwork to connect and fix through installation grooves and pressure strips to form a quadrilateral, and cement is filled inside to play a shaping role. It has the advantages of multiple recycling, low deformation rate, and scratch resistance.

[0053] Table 1 Bending performance data of composite plate of Example 1

[0054]

[0055] Note: The 1st to 12th specimens are the test serial numbers. This test is in accordance with GBT--1449-2005 standard.

[0056] Example 2

[0057] The invention discloses a low-carbon, environmentally friendly, high-impact and scratch-resistant polyester sandwich composite material, comprising an upper skin reinforcement layer, a core layer and a lower skin reinforcement layer from top to bottom, wherein the upper skin reinforcement layer and the lower skin reinforcement layer are polyester and glass fiber mixed layers, with a mass ratio of 45:55, a thickness of 0.7 mm, and a gram of 1000 g / m 2 The polyester is polyethylene terephthalate (PET), and the glass fiber is Jushi Group's 522 glass fiber. The core layer is polyethylene terephthalate (PET) foam, with a density range of 100 densities and a thickness of 8.6 mm.

[0058] The preparation method of the low-carbon, environmentally friendly, high-impact and scratch-resistant polyester sandwich composite material is as follows:

[0059] Step 1: Prepare the epidermal reinforcement layer.

[0060] The polyester is output through a single screw extruder to obtain a polyester melt. The equipment parameters are: power 24HZ, speed 11m / min, temperature 270℃; the output polyester melt is impregnated with the continuously unwound glass fiber through a mold to obtain a polyester unidirectional tape layer. The cylinder pressure during mold pressing is 6kg to obtain a polyester unidirectional tape layer. Its thickness is 0.35mm and its weight is 500g / m 2 Two single-layer polyester unidirectional tape layers are overlapped and hot-pressed at 0° / 90° to form a 0.7mm thick skin reinforcement layer with a gram weight of 1000g / m 2 The flat laminating machine uses Teflon belt to press the sheets, the pressing temperature is 200-230°C, the pressure is 5-8MPa, and the speed is 5m / min.

[0061] Step 2: Prepare the core layer. PET foam is selected as the middle core layer, with a density of 100 and a thickness of 8.6 mm.

[0062] Step 3: Composite molding. 2 Upper skin reinforcement layer, 8.6mm PET foam, 1000g / m 2 After the lower skin reinforcement layer is laid in order, it is put into the flat-plate laminating machine for lamination. The Teflon belt of the flat-plate laminating machine is the 9580A model of Shanghai Kaiyao Industrial Belt Co., Ltd., and the pressing temperature is set at 200℃, the pressure is set at 8Mpa, and the speed is 3m / min.

[0063] Step 4: Cooling and shaping to obtain the product. The composite material is cooled and shaped in the cooling area of ​​the flat-plate composite machine, and the outlet temperature is lower than 30°C to obtain a composite plate.

[0064] The product of Example 2 can be used for photovoltaic backsheet. 2 The polyester sandwich composite board is used as a photovoltaic backboard for support. EVA glue, silicon wafer, and transparent glass panel are compounded on the product of Example 2 to form a solar panel. The product of Example 2 is used as a photovoltaic backboard and has high impact resistance, scratch resistance, voltage resistance and other effects.

[0065] Table 2 Test data of composite board of Example 2

[0066]

[0067] Note: The 1st to 12th specimens are the test serial numbers. This test is in accordance with GBT--1449-2005 standard.

[0068] Example 3

[0069] The present invention discloses a polyester sandwich composite material, comprising an upper skin reinforcement layer, a core layer and a lower skin reinforcement layer from top to bottom, wherein the upper skin reinforcement layer and the lower skin reinforcement layer are a polyester and glass fiber mixed layer, and the mass ratio thereof is 45:55. The thickness of the upper skin reinforcement layer is 1.4 mm, and the gram weight is 2000 g / m 2 ; The thickness of the lower skin reinforcement layer is 1.1mm, and the weight is 1500g / m 2 The polyester is polyethylene terephthalate-1,4-cyclohexanedimethanol (PETG), and the glass fiber is Jushi Group's 522 glass fiber. The core layer is polyethylene terephthalate (PET) foam, with a density range of 150 densities and a thickness of 16.5 mm.

[0070] The preparation method of the polyester sandwich composite material is as follows:

[0071] Step 1: Prepare the epidermal reinforcement layer.

[0072] The polyester is output through a single screw extruder to obtain a polyester melt. The equipment parameters are: power 20HZ, speed 12m / min, temperature 240℃; the output polyester melt is impregnated with the continuously unwound glass fiber through a mold to obtain a polyester unidirectional tape layer. The cylinder pressure when the mold is pressed is 5kg to obtain a polyester unidirectional tape layer. Its thickness is 0.35mm and its gram weight is 500g / m 2 Four single-layer polyester unidirectional tape layers are overlapped and hot-pressed in the manner of 0° / 90° / 0° / 90° to form an upper skin reinforcement layer with a thickness of 1.4mm and a gram weight of 2000g / m 2; Then, three single-layer polyester unidirectional tape layers are overlapped and hot-pressed in the manner of 0° / 90° / 0° to form an upper skin reinforcement layer with a thickness of 1.1mm and a gram weight of 1500g / m 2 The flat laminating machine uses Teflon belt to press the sheets, the pressing temperature is 200-230°C, the pressure is 5-8MPa, and the speed is 3m / min.

[0073] Step 2: Prepare the core layer. PET foam is selected as the middle core layer, with a density of 150 mils and a thickness of 16.5 mm.

[0074] Step 3: Composite molding. 2 Upper skin reinforcement layer, 16.5mm PET foam, 1500g / m 2 After the lower skin reinforcement layer is laid in order, it is put into the flat-plate laminating machine for lamination. The Teflon belt of the flat-plate laminating machine is the 680A model of Shanghai Kaiyao Industrial Belt Co., Ltd., with the pressing temperature set at 230℃, the pressure set at 8Mpa, and the speed at 1m / min.

[0075] Step 4: Cooling and shaping to obtain the product. The composite material is cooled and shaped in the cooling area of ​​the flat-plate composite machine, and the outlet temperature is lower than 30°C to obtain a composite plate.

[0076] The product of Example 3 can be used for slide-out panels of recreational vehicle floors.

[0077] Table 3 Test data of composite board of Example 3

[0078]

[0079]

[0080] The present invention prepares a polyester sandwich composite material. The surface reinforcement layer of the material provides excellent impact resistance and scratch resistance, and the middle core layer can absorb a part of the external impact energy, thereby improving the overall impact resistance of the material. In addition, the preparation process of the material reduces the use of adhesives, reduces production costs and environmental pollution, and the material can be easily recycled and reused after being scrapped, thereby improving the environmental performance of the material.

[0081] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A polyester sandwich composite material, characterized in that: It includes an upper skin reinforcement layer, a core layer and a lower skin reinforcement layer; The upper epidermis reinforcement layer is composed of polyester and glass fiber, the mass ratio of the polyester to the glass fiber is 45:55, and the thickness is 0.7 to 2.5 mm; The lower skin reinforcement layer is composed of polyester and glass fiber, the mass ratio of the polyester to the glass fiber is 45:55, and the thickness is 0.7 to 2.5 mm; The core layer is polyethylene terephthalate foam with a density ranging from 100 to 300 mm and a thickness ranging from 4 to 20 mm.

2. The polyester sandwich composite material according to claim 1, characterized in that: The thickness of the upper epidermis reinforcement layer is 1.4 mm, and the thickness of the lower epidermis reinforcement layer is 1.4 mm.

3. The polyester sandwich composite material according to claim 1, characterized in that: The weight of the upper epidermis reinforcement layer is 1000-2000 g / m 2 The weight of the lower skin reinforcement layer is 1000-2000 g / m 2 .

4. The polyester sandwich composite material according to claim 1, characterized in that: The polyester includes polyethylene terephthalate and / or polyethylene terephthalate-1,4-cyclohexanedimethanol.

5. A method for preparing the polyester sandwich composite material according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) preparing a polyester unidirectional tape layer by melt impregnation of the polyester and glass fiber, overlapping and hot pressing N single-layer polyester unidirectional tape layers to obtain an upper skin reinforcement layer and a lower skin reinforcement layer, N ≥ 2; 2) The upper skin reinforcement layer, the lower skin reinforcement layer and the core layer obtained in step 1) are stacked in sequence, and thermally compounded to obtain a polyester sandwich composite material.

6. The preparation method according to claim 5, characterized in that: The conditions of the step 1) melt impregnation include: The polyester is output through a single screw extruder to obtain a polyester melt, and the equipment parameters are: power 20-25HZ, speed 10-12m / min, temperature 240-280°C; The outputted polyester melt is impregnated with the continuously unwound glass fiber through a mold to obtain a polyester unidirectional tape layer. The cylinder pressure during mold pressing is 5 to 6.5 kg.

7. The preparation method according to claim 5, characterized in that: The overlapping method in step 1) includes: overlapping in a manner of 0° / 90°, 0° / 90° / 0°, 0° / 90° / 0° / 90° or 0° / 90° / 90° / 0°; The conditions of the hot pressing include: a temperature of 200 to 230° C., a pressure of 5 to 8 MPa, and a speed of 3 to 5 m / min.

8. The preparation method according to claim 5, characterized in that: The conditions of the step 2) thermal compounding include: a temperature of 200 to 230° C., a pressure of 8 MPa, and a speed of 1 to 3 m / min.

9. Use of the polyester sandwich composite material according to any one of claims 1 to 4 in improving the impact resistance of composite materials.

10. Use of the polyester sandwich composite material according to any one of claims 1 to 4 in improving the scratch resistance of composite materials.

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