Composite hot melt adhesive film and preparation process thereof

Abstract

The composite hot melt adhesive film comprises a middle layer, bonding layers are arranged on the upper side and the lower side of the middle layer, and surface layers are arranged on the outer sides of the bonding layers. The preparation process of the composite hot melt adhesive film is characterized by comprising the following steps: S1, preparing the middle layer; s2, preparing a bonding layer; s3, preparing a surface layer; and S4, compounding. According to the composite hot melt adhesive film, the middle layer is arranged, elastic deformation can be generated under the stress effect, the composite hot melt adhesive film rapidly recovers to the original form after stress is relieved, the rebound resilience of the composite hot melt adhesive film is enhanced, the pressure resistance is high, the bonding layer can rapidly form firm bonding with various materials after heating and melting are conducted through the bonding layer, and the service life of the composite hot melt adhesive film is prolonged. According to the invention, the surface layer is arranged, so that the heat transfer to the bonding layer can be reduced, the conditions of softening and loose bonding in a high-temperature environment are avoided, water is prevented from entering, the viscosity of the bonding layer is improved, and the conditions of degumming or glue failure caused by water encountering are prevented.

Description

Technical Field

[0001] The invention belongs to the technical field of composite hot-melt adhesive films, and in particular relates to a composite hot-melt adhesive film and a preparation process thereof. Background Art

[0002] Composite hot melt adhesive film is a special hot melt adhesive product. It looks like a film. It is solid at room temperature, but melts and becomes sticky on both sides at high temperature. Composite hot melt adhesive film is a kind of adhesive and is widely used in bonding various materials, such as fabrics, leather, films, and foam rubber. It is particularly suitable for the clothing industry, such as the bonding of collars, plackets, cuffs, armbands, etc. It is also widely used in home textiles, shoemaking, handicrafts and other industries. In addition, composite hot melt adhesive film is also used in many fields such as electronic book covers, tablet computer bag production, seamless shoe uppers, seamless clothing, heating material lamination, clothing fabric lamination, and automotive interior lamination.

[0003] However, due to the wide application of existing composite hot melt adhesive films, they are often exposed to water, causing debonding or opening when entering and exiting, resulting in water leakage in the product. In addition, the existing composite hot melt adhesive films have poor thermal insulation properties and will soften and loosen in high temperature environments, resulting in the inability to maintain a firm bond. Therefore, there is an urgent need for a composite hot melt adhesive film and its preparation process to solve the above problems. Summary of the invention

[0004] In view of the problems raised by the above background technology, the purpose of the present invention is to provide a composite hot melt adhesive film and a preparation process thereof.

[0005] In order to achieve the above technical objectives, the technical solution adopted by the present invention is as follows:

[0006] A composite hot-melt adhesive film comprises an intermediate layer, wherein adhesive layers are arranged on the upper and lower sides of the intermediate layer, and a surface layer is arranged on the outer side of the adhesive layer.

[0007] It is further defined that the middle layer is a thermoplastic elastomer. Such a structural design can effectively absorb impact force.

[0008] It is further defined that the adhesive layer is a hot melt adhesive film. Such a structural design enables it to have an excellent adhesive effect.

[0009] It is further defined that the surface layer includes a wear-resistant layer, a heat-insulating layer and a waterproof layer, and the wear-resistant layer, the heat-insulating layer and the waterproof layer are arranged in sequence from bottom to top. Such a structural design has the effects of wear resistance, heat insulation and waterproofing.

[0010] A preparation process of a composite hot melt adhesive film, characterized in that it comprises the following steps:

[0011] S1: Prepare the middle layer, prepare TPE raw materials, heat the TPE raw materials to a molten state, and then inject them into the mold under high pressure of an injection molding machine, and obtain the required middle layer after cooling and solidification;

[0012] S2: preparing the adhesive layer, preparing the raw materials, selecting the appropriate raw materials as the base material, ensuring that the material has good thermal stability and adhesion, then putting the raw materials into a melt extruder, melting them into a uniform melt through heating and shearing, then removing impurities in the melt through a filter to ensure the purity of the hot melt adhesive, thereby improving its adhesion performance and stability, then extruding the melt through a die, and rapidly cooling it to solidify it into a hot melt adhesive film, finally, cutting the solidified hot melt adhesive film according to the required size to obtain the required adhesive layer;

[0013] S3 prepares the surface layer,

[0014] First, make the wear-resistant layer, prepare TPU particles, and preheat the TPU particles. Feed the preheated TPU particles into a twin-screw extruder, and add wear-resistant additives for mixing. Under high temperature and high pressure, the rotation of the screws fully mixes the raw materials to ensure that the wear-resistant additives are evenly distributed in the TPU particles. After mixing, the mixed material is fed into the extruder. The molten TPU and wear-resistant additive mixture is extruded into a film through the mold of the extruder head. The extruded molten wear-resistant layer is quickly cooled by a cooling device to solidify it. After solidification, it is cut according to the required size to obtain the required wear-resistant layer.

[0015] Then make the thermal insulation layer, select high-quality TPU particles as the basic raw material, and preheat the TPU particles. Send the preheated TPU particles into the twin-screw extruder, and add plasticizer, antioxidant and light stabilizer for mixing. Under high temperature and high pressure environment, the rotation of the screw makes the raw materials fully mixed and evenly distributed to ensure that the components are evenly distributed. After mixing, send it to the melt extruder for heating to melt the raw materials and mix them evenly. Finally, it is extruded into a continuous film through the die head of the extruder. After extrusion, it is quickly cooled by the cooling device to change it from liquid to solid, and cut according to the required size to obtain the required thermal insulation layer.

[0016] Then make the waterproof layer, prepare TPU particles, plasticizers, antioxidants and fillers, add TPU particles, plasticizers, antioxidants and fillers into a mixing device for stirring, send the mixed materials into a melt extruder, melt them through high temperature and shear force and extrude them into a film of a certain thickness, then the extruded film is surface treated, a top film with oil and water resistance is coated on the surface of the film, the treated film is dried and cured to remove excess moisture and volatile substances, and cut into the required size to obtain the required waterproof layer.

[0017] Finally, align and fit the wear-resistant layer, heat-insulating layer and waterproof layer from bottom to top in turn to avoid misalignment or bubbles, and use a hot-pressing laminating machine to compound them together to obtain the surface layer;

[0018] S4: Compounding, placing the middle layer obtained in S1 in the middle position, attaching the adhesive layer obtained in S2 to the upper and lower sides of the middle layer, and finally covering the surface layer on the adhesive layer. Using a hot press compounding machine, heat and pressurize the covered materials. By heating, the adhesive layer is melted, so that the middle layer and the surface layer are bonded. By pressurizing, good contact and bonding are formed between the materials. Then, the heat and pressure are maintained, and finally, the composite hot melt adhesive film is taken out and solidified and cooled to obtain.

[0019] It is further defined that in said S2, the following raw materials are included in parts by weight: 40-60 parts of polyethylene vinyl acetate, 5-20 parts of polypropylene, 5-20 parts of polybutadiene, 1-10 parts of tackifier, 1-5 parts of wax, 0.05-0.5 parts of antioxidant, 1-2.5 parts of nucleating agent, 1-3 parts of inorganic filler, 1-10 parts of plasticizer, 0.05-0.5 parts of antioxidant, 0.05-0.5 parts of chain extender, and 0.05-0.5 parts of compatibilizer.

[0020] It is further defined that the raw materials are prepared in parts by weight, including the following components: 60 parts of polyethylene vinyl acetate, 10 parts of polypropylene, 20 parts of polybutadiene, 8 parts of tackifier, 2 parts of wax, 0.5 parts of antioxidant, 2 parts of nucleating agent, 1 part of inorganic filler, 5 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer.

[0021] It is further defined that the raw materials are prepared in parts by weight, including the following components: 40 parts of polyethylene vinyl acetate, 20 parts of polypropylene, 20 parts of polybutadiene, 5 parts of tackifier, 1 part of wax, 0.5 parts of antioxidant, 1 part of nucleating agent, 3 parts of inorganic filler, 8 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer.

[0022] The beneficial effects of the present invention are as follows: by setting an intermediate layer, the present invention can produce elastic deformation under the action of force and quickly recover to its original shape after the stress is released, thereby enhancing the resilience of the composite hot-melt adhesive film and having strong pressure resistance. By setting an adhesive layer, after heating and melting, the adhesive layer can quickly form a firm bond with a variety of materials, providing a strong guarantee for the stability and durability of the product. By setting a surface layer, the heat transfer to the adhesive layer can be reduced to avoid softening and loosening of the adhesive in a high temperature environment. At the same time, water can be isolated from entering, thereby improving the viscosity of the adhesive layer and preventing debonding or opening when encountering water. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention can be further illustrated by the non-limiting examples given in the accompanying drawings;

[0024] Figure 1 This is a schematic structural diagram of a composite hot melt adhesive film according to an embodiment of the present invention;

[0025] Figure 2 This is a schematic diagram of the surface layer structure of a composite hot melt adhesive film according to an embodiment of the present invention;

[0026] The main component symbols are described as follows:

[0027] Intermediate layer 1, adhesive layer 2, surface layer 3, wear-resistant layer 4, heat-insulating layer 5, waterproof layer 6. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the present invention, the technical solution of the present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0029] like Figure 1-2 As shown, in a composite hot melt adhesive film of the present invention, an adhesive layer 2 is provided on the upper and lower sides of an intermediate layer 1 , and a surface layer 3 is provided on the outer side of the adhesive layer 2 .

[0030] Preferably, the middle layer 1 is a thermoplastic elastomer. Such a structural design can effectively absorb impact force.

[0031] Preferably, the adhesive layer 2 is a hot melt adhesive film. Such a structural design enables it to have an excellent bonding effect.

[0032] Preferably, the surface layer 3 includes a wear-resistant layer 4, a heat-insulating layer 5 and a waterproof layer 6, which are arranged in sequence from bottom to top. Such a structural design has the effects of wear resistance, heat insulation and waterproofing.

[0033] In this embodiment, the middle layer 1 is arranged between two adhesive layers 2, and the surface layer 3 is covered on the outside of the adhesive layer 2. The middle layer 1 enhances the resilience of the composite hot melt adhesive film and makes it highly resistant to compression. The adhesive layer 2 gives it excellent bonding effect and flexibility. The surface layer 3 gives the composite hot melt adhesive film wear resistance, heat insulation and waterproof effects.

[0034] A preparation process of a composite hot melt adhesive film, characterized in that it comprises the following steps:

[0035] S1: preparing the middle layer 1, preparing TPE raw materials, heating the TPE raw materials to a molten state, and then injecting the TPE raw materials into a mold through high pressure of an injection molding machine, and obtaining the desired middle layer 1 after cooling and solidification;

[0036] S2: preparing the adhesive layer 2, preparing the raw materials, selecting suitable raw materials as the base material, ensuring that the material has good thermal stability and adhesion, then putting the raw materials into a melt extruder, melting them into a uniform melt through heating and shearing, then removing impurities in the melt through a filter to ensure the purity of the hot melt adhesive, thereby improving its adhesion performance and stability, then extruding the melt through a die, and rapidly cooling it to solidify it into a hot melt adhesive film, finally, cutting the solidified hot melt adhesive film according to the required size to obtain the required adhesive layer 2;

[0037] S3 prepares surface layer 3,

[0038] First, the wear-resistant layer 4 is made, TPU particles are prepared, and the TPU particles are preheated. The preheated TPU particles are sent to a twin-screw extruder, and wear-resistant additives are added for mixing. Under high temperature and high pressure, the rotation of the screws makes the raw materials fully mixed to ensure that the wear-resistant additives are evenly distributed in the TPU particles. After mixing, the mixed material is sent to the extruder. The molten TPU and wear-resistant additive mixture is extruded into a film through the mold of the extruder head. The extruded molten wear-resistant layer is quickly cooled by a cooling device to solidify it. After solidification, it is cut according to the required size to obtain the required wear-resistant layer 4.

[0039] Then, the heat insulation layer 5 is made, high-quality TPU particles are selected as the basic raw material, and the TPU particles are preheated. The preheated TPU particles are sent to a twin-screw extruder, and plasticizer, antioxidant and light stabilizer are added for mixing. Under high temperature and high pressure environment, the rotation of the screw makes the raw materials fully mixed and uniform, ensuring that the components are evenly distributed. After mixing, the raw materials are sent to a melt extruder for heating to melt and mix evenly, and finally extruded into a continuous film through the die head of the extruder. After extrusion, it is quickly cooled by a cooling device to change it from liquid to solid, and cut according to the required size to obtain the required heat insulation layer 5.

[0040] Then, a waterproof layer 6 is made by preparing TPU particles, plasticizers, antioxidants and fillers, adding the TPU particles, plasticizers, antioxidants and fillers into a mixing device for stirring, sending the mixed materials into a melt extruder, melting them through high temperature and shear force and extruding them into a film of a certain thickness, and then the extruded film is surface treated, and a top film with oil-proof and water-proof properties is coated on the surface of the film, and the treated film is dried and cured to remove excess moisture and volatile substances, and cut according to the required size to obtain the required waterproof layer 6.

[0041] Finally, the wear-resistant layer 4, the heat-insulating layer 5 and the waterproof layer 6 are aligned and laminated from bottom to top in order to avoid misalignment or bubbles, and a hot pressing laminating machine is used to laminate them together to obtain the surface layer 3;

[0042] S4: Compounding, placing the middle layer 1 obtained in S1 in the middle position, attaching the adhesive layer 2 obtained in S2 to the upper and lower sides of the middle layer 1, and finally covering the surface layer 3 on the adhesive layer 2. Using a hot pressing compounding machine, the covered materials are heated and pressurized. The adhesive layer 2 is melted by heating, so that the middle layer 1 and the surface layer 3 are bonded. The materials are pressurized to form good contact and bonding. Then the heat and pressure are maintained, and finally the composite hot melt adhesive film is taken out and solidified and cooled to obtain the composite hot melt adhesive film.

[0043] Preferably, in S2, the following raw materials are included in parts by weight: 40-60 parts of polyethylene vinyl acetate, 5-20 parts of polypropylene, 5-20 parts of polybutadiene, 1-10 parts of tackifier, 1-5 parts of wax, 0.05-0.5 parts of antioxidant, 1-2.5 parts of nucleating agent, 1-3 parts of inorganic filler, 1-10 parts of plasticizer, 0.05-0.5 parts of antioxidant, 0.05-0.5 parts of chain extender, and 0.05-0.5 parts of compatibilizer.

[0044] Preferably, the raw materials are prepared by weight, including the following components: 60 parts of polyethylene vinyl acetate, 10 parts of polypropylene, 20 parts of polybutadiene, 8 parts of tackifier, 2 parts of wax, 0.5 parts of antioxidant, 2 parts of nucleating agent, 1 part of inorganic filler, 5 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer.

[0045] Preferably, the raw materials are prepared by weight, including the following components: 40 parts of polyethylene vinyl acetate, 20 parts of polypropylene, 20 parts of polybutadiene, 5 parts of tackifier, 1 part of wax, 0.5 parts of antioxidant, 1 part of nucleating agent, 3 parts of inorganic filler, 8 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer.

[0046] Embodiment 1

[0047] Prepare the intermediate layer 1, prepare TPE raw materials, heat the TPE raw materials to a molten state, and then inject them into the mold through the high pressure of the injection molding machine. After cooling and solidification, the required intermediate layer 1 is obtained, and the adhesive layer 2 is prepared. Prepare the raw materials, select 60 parts of polyethylene vinyl acetate, 10 parts of polypropylene, 20 parts of polybutadiene, 8 parts of tackifier, 2 parts of wax, 0.5 parts of antioxidant, 2 parts of nucleating agent, 1 part of inorganic filler, and 5 parts of plasticizer to ensure that the material has good thermal stability and adhesion. Then, put the above raw materials into a melt extruder and add 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer at the same time. Through heating and shearing, melt them into a uniform melt, and then , remove impurities in the melt through a filter to ensure the purity of the hot melt adhesive, thereby improving its adhesion and stability. Subsequently, the melt is extruded through a die and rapidly cooled to solidify into a hot melt adhesive film. Finally, the solidified hot melt adhesive film is cut according to the required size to obtain the required adhesive layer 2 and prepare the surface layer 3. First, make a wear-resistant layer 4, prepare TPU particles, and preheat the TPU particles. Feed the preheated TPU particles into a twin-screw extruder, and add a wear-resistant additive for mixing. Under high temperature and high pressure, the rotation of the screw fully mixes the raw materials to ensure that the wear-resistant additive is evenly distributed in the TPU particles. After mixing, the mixed material is fed into the extruder.The molten TPU and wear-resistant additive mixture is extruded into a film through the die of the extruder head. The extruded molten wear-resistant layer is quickly cooled by a cooling device to solidify it. After solidification, it is cut according to the required size to obtain the required wear-resistant layer 4, and then the thermal insulation layer 5 is made. High-quality TPU particles are selected as the basic raw material, and the TPU particles are preheated. The preheated TPU particles are sent to the twin-screw extruder, and plasticizers, antioxidants and light stabilizers are added for mixing. Under high temperature and high pressure environment, the rotation of the screw makes the raw materials fully mixed and uniform to ensure that the components are evenly distributed. After mixing, it is sent to the melt extruder for heating to melt the raw materials and mix them evenly. Finally, it is extruded into a continuous film through the die head of the extruder. After extrusion, it is quickly cooled by a cooling device to change it from liquid to solid, and it is cut according to the required size to obtain the required thermal insulation layer 5. Then the waterproof layer 6 is made, TPU particles, plasticizers, antioxidants and fillers are prepared, and TPU particles, plasticizers, antioxidants and fillers are added The mixed material is put into a mixing device for stirring, and the mixed material is sent to a melt extruder, where it is melted and extruded into a film of a certain thickness by high temperature and shear force. The extruded film is then surface treated, and a top film with oil and water resistance is coated on the surface of the film. The treated film is dried and cured to remove excess moisture and volatile substances, and cut according to the required size to obtain the required waterproof layer 6. Finally, the wear-resistant layer 4, the heat-insulating layer 5 and the waterproof layer 6 are aligned and fitted from bottom to top in turn to avoid misalignment or bubbles, and a hot pressing laminating machine is used to compound them together to obtain a surface layer 3; the middle layer 1 is placed in the middle position, and the adhesive layer 2 is attached to the upper and lower sides of the middle layer 1. Finally, the surface layer 3 is covered on the adhesive layer 2. The hot pressing laminating machine is used to heat and pressurize the covered material, and the adhesive layer 2 is melted by heating, so that the middle layer 1 is bonded to the surface layer 3, and the materials are formed into good contact and bonding by pressurization, and then the heat and pressure are maintained, and finally the composite hot melt adhesive film is taken out and solidified and cooled.

[0048] Embodiment 2

[0049] Prepare the intermediate layer 1, prepare TPE raw materials, heat the TPE raw materials to a molten state, and then inject them into the mold through the high pressure of the injection molding machine. After cooling and solidification, the required intermediate layer 1 is obtained, and the adhesive layer 2 is prepared. Prepare the raw materials, select 40 parts of polyethylene vinyl acetate, 20 parts of polypropylene, 20 parts of polybutadiene, 5 parts of tackifier, 1 part of wax, 0.5 parts of antioxidant, 1 part of nucleating agent, 3 parts of inorganic filler, and 8 parts of plasticizer to ensure that the material has good thermal stability and adhesion. Then, put the above raw materials into a melt extruder and add 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer at the same time. Through heating and shearing, melt them into a uniform melt, and then , remove impurities in the melt through a filter to ensure the purity of the hot melt adhesive, thereby improving its adhesion and stability. Subsequently, the melt is extruded through a die and rapidly cooled to solidify into a hot melt adhesive film. Finally, the solidified hot melt adhesive film is cut according to the required size to obtain the required adhesive layer 2 and prepare the surface layer 3. First, make a wear-resistant layer 4, prepare TPU particles, and preheat the TPU particles. Feed the preheated TPU particles into a twin-screw extruder, and add a wear-resistant additive for mixing. Under high temperature and high pressure, the rotation of the screw fully mixes the raw materials to ensure that the wear-resistant additive is evenly distributed in the TPU particles. After mixing, the mixed material is fed into the extruder.The molten TPU and wear-resistant additive mixture is extruded into a film through the die of the extruder head. The extruded molten wear-resistant layer is quickly cooled by a cooling device to solidify it. After solidification, it is cut according to the required size to obtain the required wear-resistant layer 4, and then the thermal insulation layer 5 is made. High-quality TPU particles are selected as the basic raw material, and the TPU particles are preheated. The preheated TPU particles are sent to the twin-screw extruder, and plasticizers, antioxidants and light stabilizers are added for mixing. Under high temperature and high pressure environment, the rotation of the screw makes the raw materials fully mixed and uniform to ensure that the components are evenly distributed. After mixing, it is sent to the melt extruder for heating to melt the raw materials and mix them evenly. Finally, it is extruded into a continuous film through the die head of the extruder. After extrusion, it is quickly cooled by a cooling device to change it from liquid to solid, and it is cut according to the required size to obtain the required thermal insulation layer 5. Then the waterproof layer 6 is made, TPU particles, plasticizers, antioxidants and fillers are prepared, and TPU particles, plasticizers, antioxidants and fillers are added The mixed material is put into a mixing device for stirring, and the mixed material is sent to a melt extruder, where it is melted and extruded into a film of a certain thickness by high temperature and shear force. The extruded film is then surface treated, and a top film with oil and water resistance is coated on the surface of the film. The treated film is dried and cured to remove excess moisture and volatile substances, and cut according to the required size to obtain the required waterproof layer 6. Finally, the wear-resistant layer 4, the heat-insulating layer 5 and the waterproof layer 6 are aligned and fitted from bottom to top in turn to avoid misalignment or bubbles, and a hot pressing laminating machine is used to compound them together to obtain a surface layer 3; the middle layer 1 is placed in the middle position, and the adhesive layer 2 is attached to the upper and lower sides of the middle layer 1. Finally, the surface layer 3 is covered on the adhesive layer 2. The hot pressing laminating machine is used to heat and pressurize the covered material, and the adhesive layer 2 is melted by heating, so that the middle layer 1 is bonded to the surface layer 3, and the materials are formed into good contact and bonding by pressurization, and then the heat and pressure are maintained, and finally the composite hot melt adhesive film is taken out and solidified and cooled.

[0050] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without violating the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the technical field without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A composite hot melt adhesive film, characterized in that: It comprises an intermediate layer (1), wherein an adhesive layer (2) is provided on the upper and lower sides of the intermediate layer (1), and a surface layer (3) is provided on the outer side of the adhesive layer (2).

2. The composite hot melt adhesive film according to claim 1, characterized in that: The intermediate layer (1) is a thermoplastic elastomer.

3. A composite hot melt adhesive film according to claim 2, characterized in that: The adhesive layer (2) is a hot melt adhesive film.

4. The composite hot melt adhesive film according to claim 3, characterized in that: The surface layer (3) comprises a wear-resistant layer (4), a heat-insulating layer (5) and a waterproof layer (6), and the wear-resistant layer (4), the heat-insulating layer (5) and the waterproof layer (6) are arranged in sequence from bottom to top.

5. A process for preparing the composite hot melt adhesive film according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1: preparing an intermediate layer (1), preparing a TPE raw material, heating the TPE raw material to a molten state, and then injecting the TPE raw material into a mold under high pressure of an injection molding machine, and obtaining the desired intermediate layer (1) after cooling and solidification; S2: preparing the adhesive layer (2), preparing the raw materials, selecting suitable raw materials as the base material, ensuring that the material has good thermal stability and adhesion, then putting the raw materials into a melt extruder, melting them into a uniform melt through heating and shearing, then removing impurities in the melt through a filter to ensure the purity of the hot melt adhesive, thereby improving its adhesion performance and stability, then extruding the melt through a die, and rapidly cooling it to solidify it into a hot melt adhesive film, and finally cutting the solidified hot melt adhesive film into a required size to obtain the required adhesive layer (2); S3 prepares a surface layer (3), First, the wear-resistant layer (4) is prepared, TPU particles are prepared, and the TPU particles are preheated. The preheated TPU particles are fed into a twin-screw extruder, and a wear-resistant additive is added for mixing. Under a high temperature and high pressure environment, the rotation of the screw allows the raw materials to be fully mixed to ensure that the wear-resistant additive is evenly distributed in the TPU particles. After mixing, the mixed material is fed into the extruder. The molten TPU and the wear-resistant additive mixture is extruded into a film through the mold of the extruder head. The extruded molten wear-resistant layer is quickly cooled by a cooling device to solidify it. After solidification, it is cut according to the required size to obtain the required wear-resistant layer (4). Then, a heat insulating layer (5) is prepared. High-quality TPU particles are selected as the basic raw material, and the TPU particles are preheated. The preheated TPU particles are sent to a twin-screw extruder, and plasticizer, antioxidant and light stabilizer are added to mix them. Under high temperature and high pressure, the rotation of the screw makes the raw materials fully mixed and uniform, ensuring that the components are evenly distributed. After mixing, the raw materials are sent to a melt extruder for heating to melt and mix them evenly. Finally, they are extruded into a continuous film through the die head of the extruder. After extrusion, they are quickly cooled by a cooling device to change from liquid to solid, and cut according to the required size to obtain the required heat insulating layer (5). Then, a waterproof layer (6) is prepared by preparing TPU particles, plasticizer, antioxidant and filler, adding the TPU particles, plasticizer, antioxidant and filler into a mixing device for stirring, sending the mixed material into a melt extruder, melting it through high temperature and shear force and extruding it into a film of a certain thickness, then the extruded film is surface treated, a top film with oil-proof and water-proof properties is coated on the surface of the film, the treated film is dried and cured to remove excess moisture and volatile substances, and cut into a required size to obtain the required waterproof layer (6), Finally, the wear-resistant layer (4), the heat-insulating layer (5) and the waterproof layer (6) are aligned and laminated from bottom to top in order to avoid misalignment or bubbles, and a hot-pressing laminating machine is used to laminate them together to obtain the surface layer (3); S4: Compounding, placing the middle layer (1) obtained in S1 in the middle position, attaching the adhesive layer (2) obtained in S2 to the upper and lower sides of the middle layer (1), and finally covering the surface layer (3) on the adhesive layer (2). Using a hot press compounding machine, the covered materials are heated and pressurized. The adhesive layer (2) is melted by heating, so that the middle layer (1) and the surface layer (3) are bonded. The materials are pressurized to form good contact and adhesion. Then the heat and pressure are maintained. Finally, the composite hot melt adhesive film is taken out and solidified and cooled to obtain the composite hot melt adhesive film.

6. The process for preparing a composite hot melt adhesive film according to claim 5, characterized in that: In the S2, the following raw materials are included in parts by weight: 40-60 parts of polyethylene vinyl acetate, 5-20 parts of polypropylene, 5-20 parts of polybutadiene, 1-10 parts of tackifier, 1-5 parts of wax, 0.05-0.5 parts of antioxidant, 1-2.5 parts of nucleating agent, 1-3 parts of inorganic filler, 1-10 parts of plasticizer, 0.05-0.5 parts of antioxidant, 0.05-0.5 parts of chain extender, and 0.05-0.5 parts of compatibilizer.

7. The process for preparing a composite hot melt adhesive film according to claim 6, characterized in that: Prepare raw materials by weight, including the following components: 60 parts of polyethylene vinyl acetate, 10 parts of polypropylene, 20 parts of polybutadiene, 8 parts of tackifier, 2 parts of wax, 0.5 parts of antioxidant, 2 parts of nucleating agent, 1 part of inorganic filler, 5 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer.

8. The process for preparing a composite hot melt adhesive film according to claim 7, characterized in that: Prepare raw materials by weight, including the following components: 40 parts of polyethylene vinyl acetate, 20 parts of polypropylene, 20 parts of polybutadiene, 5 parts of tackifier, 1 part of wax, 0.5 parts of antioxidant, 1 part of nucleating agent, 3 parts of inorganic filler, 8 parts of plasticizer, 0.5 parts of antioxidant, 0.5 parts of chain extender, and 0.5 parts of compatibilizer.

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