PET enhanced PE foam composite material and preparation method thereof

Abstract

The invention provides a PET enhanced PE foam composite material which comprises a PE foam base material layer, a bonding layer and a PET base material layer, the bonding layer is located between the PE foam base material layer and the PET base material layer, the PE foam base material layer is made of PE foam with the density being 0.05-0.3 g / cm < 3 > and the average cell diameter being 50-200 microns, the bonding layer is made of an acrylate adhesive with the thickness being 0.01-0.05 mm, and the PET base material layer is made of a PET adhesive with the thickness being 0.01-0.05 mm. The PET base material layer adopts a transparent PET film original film with the thickness of 0.01-0.1 mm, the prepared foam composite material has excellent mechanical properties, excellent structural stability and multifunctional integration, the adopted preparation method is simple in process, controllable in operation, clear in parameters of each step and suitable for large-scale industrial production, and by accurately controlling the process parameters, the foam composite material can be used for preparing a foam composite material with good mechanical properties. And the composite material with excellent performance can be stably produced.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, and in particular to a PET-reinforced PE foam composite material and a preparation method thereof. Background Art

[0002] Polyethylene (PE) foam is a common polymer material. Due to its lightweight, excellent cushioning properties, and chemical resistance, it is widely used in a variety of fields, including packaging, electronics, digital products, and automotive interiors. However, existing PE foam has several significant shortcomings, including insufficient tensile strength, poor tear resistance, delamination, poor dimensional stability, and limited functionality.

[0003] Traditional PE foam has a relatively loose internal pore structure and weak interactions between its molecular chains, making it ineffective at dispersing stress under tensile loads. When used in the packaging industry to cushion and secure electronic products, the PE foam can easily break if subjected to severe strain during transportation, leaving the product inside unprotected and causing economic losses. Extensive experimental testing has shown that the tensile strength of conventional PE foam is generally only 2-4 MPa, far from meeting the requirements of some high-strength applications. Because PE foam's pore walls are thin and contain numerous stress concentration points, it is highly susceptible to tearing when scratched by sharp objects or subjected to localized stress, which can rapidly expand to form large cracks. For example, in the case of accidental scratches on automotive interiors, PE foam interior components can suffer extensive tears, severely impacting their appearance and performance. During the PE foam production process, due to the foaming process and the inherent properties of the material, the foam exhibits varying degrees of density gradients and molecular orientation differences. When peeled by external forces, these differences can lead to insufficient bonding between the foam substrate layers, resulting in delamination. PE foam sheets used for sound insulation and heat insulation in the field of building decoration often delaminate due to peeling operations during installation or disassembly, which greatly reduces the performance of the material.

[0004] While various attempts have been made to improve these issues by adjusting the PE foam formulation (such as adding fillers or reinforcing fibers) or by refining the foaming process, these approaches have numerous limitations, and no single method has yet effectively addressed both the breakage and delamination issues of PE foam. Adding fillers or reinforcing fibers often disrupts the foam's pore structure, reducing its cushioning properties and softness. Improving the foaming process, however, faces challenges such as high cost, complex processes, and difficulty in large-scale production, and the results remain suboptimal. Therefore, developing a new, high-strength PE foam composite material has become a crucial technical challenge. Summary of the Invention

[0005] In order to solve the above technical problems, the first aspect of the present invention provides a PET-reinforced PE foam composite material, comprising a PE foam substrate layer, an adhesive layer and a PET substrate layer; The bonding layer is located between the PE foam substrate layer and the PET substrate layer, tightly bonding the two together; The PE foam substrate layer has a density of 0.05-0.3 g / cm 3 The PE foam has a uniform cell structure and an average cell diameter of 50-200 μm; The bonding layer is an acrylic adhesive with a thickness of 0.01-0.05 mm; The PET substrate layer is a transparent PET film original film with a thickness of 0.01-0.1 mm.

[0006] Furthermore, the surface of the PE foam substrate layer is corona treated at a power of 10-50kW for a time of 0.5-2 seconds to improve the bonding between the PE foam substrate layer and the adhesive layer. Corona treatment can introduce a large number of polar groups to the PE foam surface, increasing surface roughness, thereby significantly improving surface activity and adhesive properties.

[0007] Furthermore, the surface of the PET substrate layer is coated with a layer of silane coupling agent, with a coating amount of 1-5 g / m 2 , to enhance the bonding strength between the PET substrate layer and the adhesive layer. Silane coupling agents can form chemical bonds on the PET surface and simultaneously undergo cross-linking reactions with acrylic adhesives to form a strong interface layer.

[0008] The second aspect of the present invention provides a method for preparing a PET-reinforced PE foam composite material, the specific steps of which are as follows: S1. PE foam substrate layer treatment: The PE foam is cut to meet the required size. The dimensional tolerance of the cut PE foam is controlled within ±0.5mm. The surface of the PE foam layer is then corona treated at a power of 10-50kW for a treatment time of 0.5-3s to increase its surface activity.

[0009] S2. PET substrate layer treatment: Cut the transparent PET film and apply silane coupling agent on both sides by coating. The roller coating speed is 0.5-2m / min and the coating amount is 1-5g / m 2 After coating, dry at 80-120℃ for 2-20 minutes to fully cure the silane coupling agent.

[0010] S3. Applying the Adhesive Layer: Apply an acrylic adhesive evenly to the treated PET film substrate using a blade coating method. The angle between the blade and the PET substrate layer is 30-60°, and the coating thickness of the adhesive is controlled to be 0.01-0.05mm.

[0011] S4. Composite: Laminate the adhesive-coated PET substrate layer and the treated PE foam substrate layer. Hot-press the laminate at a pressure of 0.4-0.5 MPa and a temperature of 50-80°C. Maintain the uniformity of the heating plate temperature within ±2°C for 1-5 minutes to ensure a tight bond between the two layers. This results in a PET-reinforced PE foam composite material. The resulting composite material is then aged at a temperature of 20-25°C and a relative humidity of 40-60% for 24-48 hours to eliminate internal stress and stabilize material properties.

[0012] Furthermore, in the PE foam substrate layer processing step, the PE foam is pre-dried before cutting, with a drying temperature of 50-80° C. and a drying time of 10-30 minutes.

[0013] Furthermore, in the step of coating the adhesive layer, the solid content of the acrylic adhesive is 30-50%, and before coating, it is stirred at 20-40° C., at a stirring speed of 100-300 r / min, and for 5-15 min.

[0014] Furthermore, in the compounding step, the composite material is subjected to a cooling and setting treatment after hot pressing and compounding, with a cooling temperature of 10-30° C. and a cooling time of 1-2 minutes.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. Excellent mechanical performance improvement: PET substrate has the characteristics of high strength and high modulus. When compounded with PE foam, it can effectively bear tensile loads and disperse stress, greatly improving the tensile strength of the composite material to above 4-8MPa, which is 2-3 times higher than that of traditional PE foam, effectively solving the problem of easy breakage. At the same time, the presence of PET inhibits the expansion of cell tearing, significantly enhancing the material's tear resistance.

[0016] 2. Excellent structural stability: By surface treating the PE foam substrate layer and the PET substrate layer, combined with the strong bonding effect of the acrylic adhesive, the bonding strength between the two layers is greatly improved, and the peel strength can reach over 12-20N / 25mm, effectively avoiding peeling and delamination. In addition, the presence of PET also enhances the dimensional stability of the composite material, significantly reducing its deformation in high and low temperature environments.

[0017] 3. Multifunctional Integration: The introduction of PET film imparts excellent toughness to the composite material while retaining the cushioning properties of PE foam. This achieves the integration of multiple functions, including cushioning protection and high strength and toughness, expanding the material's application in areas such as electronic displays and optical instruments.

[0018] 4. Process Advantages: The preparation method of the present invention features simple process, controllable operation, and clear parameters for each step, making it suitable for large-scale industrial production. Furthermore, by precisely controlling the process parameters, it can stably produce composite materials with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of a PET reinforced PE foam composite material described in the present invention.

[0020] Reference numerals: 1-PE foam substrate layer; 2-adhesive layer; 3-PET substrate layer. DETAILED DESCRIPTION

[0021] Example 1 S1. PE foam substrate layer treatment: select a density of 0.2g / cm 3 PE foam with an average cell diameter of 100 μm was cut into appropriate sizes with a dimensional tolerance of ±0.5 mm. The surface of the PE foam substrate layer was then corona treated with a treatment power of 15 kW and a treatment time of 1 second.

[0022] S2. PET substrate layer treatment: Select a transparent PET film with a thickness of 0.012mm, cut it, and apply silane coupling agent to the surface by roller coating at a speed of 1m / min and a coating amount of 2g / m 2 After coating, dry at 90℃ for 3 minutes.

[0023] S3. Applying an adhesive layer: Apply an acrylic adhesive evenly to the treated PET substrate surface using a blade coating method. The angle between the blade and the PET substrate surface is 45°, and the coating thickness of the adhesive is controlled to be 0.01 mm.

[0024] S4. Composite: Laminate the adhesive-coated PET substrate layer and the treated PE foam layer. Heat press the laminate at a pressure of 0.4 MPa and a temperature of 60°C. The temperature uniformity of the hot press plate should be controlled within ±2°C for 2 minutes to produce a PET-reinforced PE foam composite. After production, the composite is aged for 24 hours at a temperature of 23°C and a relative humidity of 50%.

[0025] Example 2 S1. PE foam substrate layer treatment: select a density of 0.3g / cm 3 PE foam with an average cell diameter of 150 μm was cut into appropriate sizes with a dimensional tolerance of ±0.5 mm. The surface of the PE foam substrate layer was then corona treated with a treatment power of 20 kW and a treatment time of 3 seconds.

[0026] S2. PET substrate layer treatment: Select a transparent PET film with a thickness of 0.025mm, cut it, and apply the silane coupling agent by roller coating. The roller coating speed is 1.5m / min and the coating amount is 3g / m 2 , dried at 100℃ for 2min.

[0027] S3. Applying an adhesive layer: Apply an acrylic adhesive to the surface of the PET substrate layer with a scraper at an angle of 50° to the surface of the PET substrate layer and a thickness of 0.02 mm.

[0028] S4. Composite: Laminate the adhesive-coated PET substrate layer and the treated PE foam layer. Heat press the laminate at a pressure of 0.5 MPa and a temperature of 70°C. The temperature uniformity of the hot press plate should be controlled within ±2°C for 3 minutes to produce a PET-reinforced PE foam composite material. After production, age the composite material at a temperature of 23°C and a relative humidity of 55% for 36 hours.

[0029] Comparative Example 1 Original PE foam that is not compounded with PET is used, and its parameters such as density and cell structure are the same as those of the PE foam in Example 1.

[0030] The composite materials prepared in Example 1 and Example 2 and the original PE foam of Comparative Example 1 were subjected to tensile strength tests. The test results are shown in the following table: Table 1 - Foam test results sample Tensile strength MPa Example 1 8.5 Example 2 9.2 Comparative Example 1 3.2 As can be seen from the data in the above table, the PET-reinforced PE foam composite material prepared in the present invention has significantly improved tensile strength compared to the original PE foam, effectively solving the defects of the existing PE foam.

[0031] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structures made using the contents of the present invention's description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A PET-reinforced PE foam composite material comprising a PE foam substrate layer, an adhesive layer, and a PET substrate layer; The bonding layer is located between the PE foam substrate layer and the PET substrate layer, tightly bonding the two together; The PE foam substrate layer has a density of 0.05-0.3 g / cm 3 The PE foam has a uniform cell structure and an average cell diameter of 50-200 μm; The bonding layer is an acrylic adhesive with a thickness of 0.01-0.05 mm; The PET substrate layer is a transparent PET film original film with a thickness of 0.01-0.1 mm.

2. A PET reinforced PE foam composite material according to claim 1, characterized in that: The surface of the PE foam substrate layer is subjected to corona treatment with a treatment power of 10-50 kW and a treatment time of 0.5-2 s.

3. A PET reinforced PE foam composite material according to claim 1, characterized in that: The surface of the PET substrate layer is coated with a silane coupling agent in an amount of 1-5 g / m 2 .

4. The method for preparing a PET-enhanced PE foam composite material according to any one of claims 1 to 3, wherein: The method comprises the following preparation steps: S1. PE foam substrate layer treatment: The PE foam is cut to meet the required dimensions, with a dimensional tolerance of ±0.5mm. The surface of the PE foam layer is then corona treated at a power of 10-50kW for a treatment time of 0.5-3s. S2. PET substrate layer treatment: Cut the transparent PET film and apply silane coupling agent on both sides by roller coating. The roller coating speed is 0.5-2m / min and the coating amount is 1-5g / m 2 After coating, dry at 80-120℃ for 2-20min to fully cure the silane coupling agent; S3 coating adhesive layer: the acrylic adhesive is evenly coated on the surface of the treated PET film substrate layer by a doctor blade coating method, the angle between the doctor blade and the surface of the PET substrate layer is 30-60 °, the coating thickness of the adhesive is controlled at 0.01-0.05mm; S4. Composite: Laminate the adhesive-coated PET substrate layer and the treated PE foam substrate layer. Hot-press the laminate at a pressure of 0.4-0.5 MPa and a temperature of 50-80°C. Maintain the uniformity of the heating plate temperature within ±2°C for 1-5 minutes to ensure a tight bond between the two layers. This results in a PET-reinforced PE foam composite material. The resulting composite material is then aged at a temperature of 20-25°C and a relative humidity of 40-60% for 24-48 hours to eliminate internal stress and stabilize material properties.

5. The method for preparing a PET-enhanced PE foam composite material according to claim 4, wherein: In the PE foam substrate layer processing step, the PE foam is pre-dried before cutting, with a drying temperature of 50-80° C. and a drying time of 10-30 min.

6. The method for preparing a PET-enhanced PE foam composite material according to claim 4, wherein: In the step of coating the bonding layer, the solid content of the acrylic adhesive is 30-50%, and before coating, it is stirred at 20-40° C., at a stirring speed of 100-300 r / min, and for 5-15 min.

7. The method for preparing a PET-enhanced PE foam composite material according to claim 4, wherein: In the compounding step, the composite material is cooled and shaped after hot pressing and compounding, the cooling temperature is 10-30° C., and the cooling time is 1-2 minutes.

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