Preparation process of paper protective inflatable bubble bag composite film and product of paper protective inflatable bubble bag composite film

Abstract

The invention relates to the technical field of inflatable bubble bag composite film processing, in particular to a preparation process of a paper protective inflatable bubble bag composite film and a product thereof, and the preparation process comprises the following preparation steps: S1, coating waterproof and air-isolating glue on the surface of a base material, and drying to form a waterproof and air-isolating layer to obtain a waterproof and air-isolating composite film, the waterproof and air-insulation glue is prepared by mixing polyvinyl alcohol, polyurethane modified organic silicon, water-soluble chitosan, water-soluble acrylic resin, 2-ethylhexyl acrylate, a cross-linking agent, ethanol and water; s2, the kraft paper and the waterproof and air-proof composite film are pressed at the pressing temperature of 140-150 DEG C and the pressing pressure of 12-16 MPa, so that the kraft paper and the waterproof and air-proof layer are adhered to each other, and a kraft paper composite film is obtained; s3, tearing off the base material layer; and S4, the surface of the waterproof and air insulation layer is coated with heat sealing glue, drying is conducted, and the paper protective inflatable bubble bag composite film is obtained and has good waterproof and air insulation performance.

Description

Technical Field

[0001] The present application relates to the technical field of processing of composite films of inflatable bubble bags, and more specifically, to a preparation process of a composite film of a paper protective inflatable bubble bag and a product thereof. Background Art

[0002] Express bubble bags are a new type of packaging material. They mainly use the gas in the bubble bags to cushion and protect. They are usually made of plastic. With the development of express delivery business, the amount of express bubble bags required has greatly increased, and more waste plastics have been generated, resulting in more serious plastic pollution. In order to improve the pollution problem of plastic express bubble bags, paper bubble bags are used to replace some plastic bags.

[0003] At present, the existing paper cushioning bubble bag is prepared by the following method: a layer of functional glue is coated on the surface of kraft paper to form a waterproof and air-proof layer to obtain a kraft paper composite film, and then the kraft paper composite film is prepared into a paper cushioning bubble bag. In actual use, it is found that the gas in the paper cushioning bubble bag will be slowly released over time, resulting in a decrease in the cushioning performance of the paper cushioning bubble bag.

[0004] The main reason is that the kraft paper is breathable and has an uneven surface, which results in uneven glue coating, so that the glue layer and the kraft paper layer cannot be completely adhered, and the gas in the paper cushioning bubble bag will gradually release into the external environment over time. Although this process is slow, it will cause the gas pressure inside the bubble bag to decrease, thereby affecting its cushioning performance. When the gas is released to a certain extent, the cushioning effect of the paper cushioning bubble bag will be greatly reduced, and it can no longer provide sufficient protection for the items in the package. Summary of the invention

[0005] In order to improve the adhesion stability between the kraft paper layer and the waterproof and air-barrier layer and improve the air-barrier effect of the kraft composite film, the present application provides a preparation process of a paper protective inflatable bubble bag composite film and a product thereof.

[0006] In the first aspect, the present application provides a preparation process of a paper protective inflatable bubble bag composite film, which adopts the following technical solution: A preparation process of a paper protective inflatable bubble bag composite film comprises the following preparation steps: S1, coating a waterproof and air-proof glue on the surface of the substrate, drying, forming a waterproof and air-proof layer, and obtaining a waterproof and air-proof composite film, wherein the waterproof and air-proof glue is prepared by mixing polyvinyl alcohol, polyurethane-modified silicone, water-soluble chitosan, water-soluble acrylic resin, isooctyl acrylate, a cross-linking agent, ethanol, and water; S2, pressing the kraft paper and the waterproof and air-tight composite film at a pressing temperature of 140-150° C. and a pressing pressure of 12-16 MPa, so that the kraft paper and the waterproof and air-tight layer adhere to each other to obtain a kraft paper composite film; S3, tear off the substrate layer; S4. Apply heat-sealing glue on the surface of the waterproof and air-barrier layer, and dry it to obtain a paper protective inflatable bubble bag composite film.

[0007] By adopting the above technical scheme, the prepared paper protective inflatable bubble bag composite film has good waterproof and air-proof properties. A layer of waterproof and air-proof glue mixed with multiple components is first coated on the substrate, and then dried to form a waterproof and air-proof layer, the uniformity and density of the waterproof and air-proof layer are ensured, and then pressed with kraft paper, which solves the problem of weak adhesion and easy air leakage caused by uneven glue coating. Compared with the original scheme, directly coating the functional glue on the kraft paper is more dense and uniform, which can effectively reduce the release of gas through the air permeability of the kraft paper. The kraft paper and the waterproof and air-proof composite film are pressed under high temperature and high pressure conditions, which makes the adhesion between the two stronger, reduces the possibility of gas leakage, and enhances the overall structural strength of the bubble bag.

[0008] The waterproof and air-isolating glue not only has excellent waterproof performance, but also can effectively isolate gas penetration, greatly slowing down the release rate of gas inside the bubble bag, thereby maintaining the long-term buffering effect of the bubble bag. In this application, a waterproof and air-isolating glue prepared with composite materials such as polyvinyl alcohol, polyurethane-modified silicone, water-soluble chitosan, water-soluble acrylic resin, and isooctyl acrylate is used to form a dense waterproof and air-isolating layer on the surface of the substrate. Among them, the polyurethane-modified silicone, acrylic resin and isooctyl acrylate work together to give the composite film excellent waterproof performance, which can effectively block water penetration; the sealing property of the polyurethane-modified silicone and the effect of the cross-linking agent make the composite film have excellent air-isolating performance and prevent gas leakage; polyvinyl alcohol and water-soluble chitosan enhance the adhesion of the glue to the substrate, and at the same time form a uniform and dense film layer. The cross-linking agent is used to promote the cross-linking reaction between resin molecules and enhance the stability and adhesion of the glue.

[0009] By precisely controlling the lamination temperature and pressure, better adhesion is achieved between the kraft paper and the waterproof and air-barrier layer, which not only reduces the possibility of gas release through the tiny gap between the kraft paper and the glue layer, but also enhances the overall structural strength of the composite film and improves the durability and reliability of the bubble bag.

[0010] The heat-sealing glue has good adhesion and heat-sealing properties, and can seal the bubble bag by heating in the subsequent bag-making process. After the heat-sealing glue is coated on the surface of the waterproof and air-barrier layer and dried, a paper-based protective inflatable bubble bag composite film with excellent sealing properties is obtained.

[0011] Preferably, the weight percentages of the raw materials used to prepare the waterproof and air-isolating glue are as follows: Polyvinyl alcohol 10-20% Polyurethane modified silicone 5-8% Water-soluble chitosan 3-4% Water-soluble acrylic resin 10-15% Isooctyl acrylate 10-15% Crosslinking agent 0.5-1% Ethanol 15-25% The balance is water.

[0012] By adopting the above technical scheme, the weight of the raw materials used to prepare the waterproof and air-barrier glue is optimized, so that the viscosity of the waterproof and air-barrier glue is moderate, easy to coat, and has good film-forming properties. At the same time, the formed film layer has excellent waterproof and air-barrier properties, adhesion, weather resistance and water resistance, which is conducive to compounding with kraft paper, while ensuring that gas does not leak.

[0013] Preferably, the waterproof and air-isolating glue is prepared by the following method: Mix water and ethanol, then add water-soluble chitosan, water-soluble acrylic resin and polyvinyl alcohol, stir until all are dissolved, then add polyurethane-modified silicone, isooctyl acrylate and a cross-linking agent and stir evenly to obtain a waterproof and air-tight glue.

[0014] By adopting the above technical solutions, it is helpful to form a uniform mixing system Preferably, the coating weight of the waterproof and air-isolating glue is 30-40 g / m 2 .

[0015] At this coating moisture, the waterproof and air-barrier glue can form a relatively uniform and continuous film, effectively blocking the penetration of water and gas, and improving the waterproof and air permeability of the paper protective inflatable bubble bag composite film. Too little coating may lead to an incomplete film layer, affecting the waterproof and air-barrier effect; while too much coating may cause waste and even affect the drying speed and performance of the film layer.

[0016] Preferably, the drying temperature in step S1 is 120-130° C. and the drying speed is 60-70 m / min.

[0017] By adopting the above technical solution, the evaporation of ethanol and water can be accelerated, the formation of the film can be promoted, and the glue can be prevented from drying too quickly and hardening the surface due to high temperature, resulting in defects such as cracks and bubbles on the surface of the film layer, and the low production efficiency caused by slow drying speed when the temperature is too low can be prevented. The speed of 60-70m / min is relatively moderate, which can ensure that the film layer is uniformly and fully cured during the drying process. Too fast drying speed will cause the surface of the film layer to harden quickly while the internal solvent has not completely evaporated, thereby causing internal stress or cracking problems, and ultimately affecting the waterproof and airtight effect.

[0018] Preferably, the heat-sealing glue is prepared from the following raw materials in percentage by weight: Polyvinyl alcohol 15-20% Polyurethane modified silicone 5-8% Ethylene-vinyl acetate copolymer emulsion 5-9% Curing agent 0.5-1% Ethanol 10-20% The balance is water.

[0019] By adopting the above technical scheme, the prepared heat-sealing glue has excellent film-forming property, adhesion, water resistance and weather resistance, and is rapidly solidified during the heat-sealing process to form a stable and reliable sealing layer, which effectively prevents the internal shape of the bubble bag from leaking. Polyvinyl alcohol can ensure that the glue forms a continuous and uniform film layer after drying, while maintaining sufficient flexibility and elasticity to adapt to the deformation of the bubble bag during transportation and use. Polyurethane-modified silicone can effectively improve the stability of the glue in harsh environments such as high temperature and high humidity, and prevent the glue from aging, cracking or losing adhesion. At the same time, polyurethane-modified silicone also has a certain lubricity, which helps to improve the fluidity of the glue during the coating process and reduce the generation of defects such as bubbles and pinholes. At the same time, since polyvinyl alcohol and polyurethane-modified silicone are present in the heat-sealing glue, it is beneficial to stably connect the heat-sealing layer with the waterproof and air-proof layer to prevent the two from being separated during use. Adding an appropriate amount of EVA emulsion to the heat-sealing glue can make the glue form a softer and more elastic film layer after curing, which is more suitable for the morphological changes of the bubble bag and prevents the bubble bag from leaking due to deformation. The curing agent promotes the cross-linking reaction of the polymer components in the glue under heating conditions to form a stable three-dimensional network structure.

[0020] Preferably, the coating weight of the heat-sealing glue is 5-10 g / m 2 .

[0021] By adopting the above technical solution, the heat-sealing glue can be evenly coated on the surface of the waterproof and air-barrier layer, forming good adhesion with the waterproof and air-barrier layer, and ensuring the sealing of the bubble bag. At the same time, within the coating moisture range, the viscosity of the heat-sealing glue is moderate, and it is easy to be evenly coated by a coating machine or other coating equipment, reducing waste and defects in the coating process.

[0022] Preferably, before step S4, polyurethane glue is coated on the surface of the waterproof and air-barrier layer and dried to obtain a polyurethane composite film.

[0023] By adopting the above technical solution, the folding resistance and toughness of the composite film of the paper protective inflatable bubble bag are increased. Polyurethane glue has excellent strength and toughness. After being coated on the surface of the waterproof and air-proof layer, it can give the composite film better flexibility and strength, so that the bubble bag is not easy to be damaged or cracked when it is repeatedly folded or bent, and can adapt to packaging items of various shapes and sizes. At the same time, when it is squeezed or impacted, it can better absorb and disperse stress to protect the internal items from damage. At the same time, the polyurethane glue is tightly combined with the waterproof and air-proof layer to form a solid protective layer. This protective layer can effectively resist the tearing of external mechanical forces, prevent the bubble bag from being torn due to external forces during transportation and use, and can be used for large and fragile express delivery.

[0024] Preferably, the coating weight of the polyurethane glue is 10-15 g / m 2 .

[0025] By adopting the above technical solution, the coating amount of polyurethane glue is optimized so that the polyurethane glue can form a continuous coating on the surface of the waterproof and air-insulating glue, ensuring the toughness and bending resistance of the paper protective inflatable bubble bag composite film. Too much coating amount may cause glue waste and prolong the drying time, while too little coating amount may not ensure good adhesion and sealing.

[0026] In the second aspect, the present application provides a paper protective inflatable bubble bag composite film, which adopts the following technical solution: A paper protective inflatable bubble bag composite film is prepared by the paper protective inflatable bubble bag composite film preparation process described in the first aspect.

[0027] By adopting the above technical scheme, the prepared paper protective inflatable bubble bag composite film has good waterproof and air-tight properties, and also has good toughness, so that it is not easily damaged during use.

[0028] In summary, this application has the following beneficial effects: 1. Excellent waterproof and air-tight performance: Through the use of waterproof and air-tight glue and high-temperature and high-pressure lamination process, the composite film can effectively block the penetration of moisture and gas, ensuring the stability of the gas pressure inside the bubble bag.

[0029] 2. Good adhesion strength: The close adhesion between kraft paper and the waterproof and air barrier layer ensures the overall strength and durability of the composite film.

[0030] 3. Excellent sealing performance: The use of heat-sealing glue enables the bubble bag to maintain a good sealing state after inflation, preventing gas leakage and the intrusion of external pollutants.

[0031] 4. Long-lasting cushioning effect: Due to the enhanced waterproof and air-tight properties and the stability of gas pressure, the bubble bag made of composite film can maintain excellent cushioning effect for a long time, providing full protection for the items in the package. DETAILED DESCRIPTION

[0032] The water-soluble acrylic resin was purchased from Guangdong Dingxin Polymer Technology Co., Ltd. The brand is Japanese Mitsubishi and the model is BR116.

[0033] Polyurethane modified silicone was purchased from Shanghai Shuai Ke Chemical Co., Ltd., model number SK7808.

[0034] Polyvinyl alcohol was purchased from Dongguan Yingxiang Plastic Raw Materials Co., Ltd. The brand is Japanese Kuraray and the model is AX-600.

[0035] Ethylene-vinyl acetate copolymer emulsion was purchased from Shandong New Kinetic Energy Chemical Co., Ltd., model 707.

[0036] Preparation Example Preparation Example 1 A waterproof and air-tight glue is prepared by the following method: Mix 220g of water and 250g of ethanol, then add 40g of water-soluble chitosan, 150g of water-soluble acrylic resin and 100g of polyvinyl alcohol, stir until all are dissolved, then add 80g of polyurethane-modified silicone, 150g of isooctyl acrylate and 10g of cross-linking agent (toluene diisocyanate), stir evenly to obtain a waterproof and air-proof glue.

[0037] The difference between Preparation Example 2-3 and Preparation Example 1 is that the types, amounts and experimental parameters of some raw materials for preparing the waterproof and air-tight glue are different. The specific differences are shown in Table 1: Table 1 Raw material types, dosages and experimental parameters for preparing waterproof and airtight glue in Preparation Examples 1-3 Preparation Example 4 A heat-sealing glue is prepared by the following method: 100 g of polyvinyl alcohol, 80 g of polyurethane-modified silicone, 90 g of ethylene-vinyl acetate copolymer emulsion, 10 g of curing agent (ethyl orthosilicate), 200 g of ethanol and 520 g of water are stirred and uniformly obtained.

[0038] The difference between Preparation Example 5-6 and Preparation Example 5 is that the types, amounts and experimental parameters of some raw materials for preparing the heat-sealing glue are different. The specific differences are shown in Table 2: Table 2 Types, amounts and experimental parameters of raw materials for preparing heat-sealing glue in Preparation Examples 4-6 Preparation Comparative Example Preparation Comparative Example 1 A waterproof and air-tight glue, the difference between this preparation comparative example and preparation example 1 is that polyvinyl pyrrolidone is used instead of polyvinyl alcohol.

[0039] Polyvinyl pyrrolidone was purchased from Jinan Pengduo Trading Co., Ltd., model 30.

[0040] Preparation Comparative Example 2 A waterproof and air-tight glue, the difference between this preparation comparative example and preparation example 1 is that epoxy resin is used instead of polyurethane-modified silicone.

[0041] The epoxy resin was purchased from Wuhan Mengqi Technology Co., Ltd., model number TL-017481.

[0042] Preparation Comparative Example 3 A waterproof and air-tight glue, the difference between this preparation comparative example and preparation example 1 is that carboxymethyl cellulose is used instead of water-soluble chitosan.

[0043] Preparation Comparative Example 4 A waterproof and air-tight glue, the difference between this preparation comparative example and preparation example 1 is that a water-soluble epoxy resin is used instead of a water-soluble acrylic resin.

[0044] The water-soluble epoxy resin was purchased from Jining Fangyu Chemical Co., Ltd. with the brand name J-990. Example

[0045] Example 1 A paper protective inflatable bubble bag composite film is prepared by the following method: S1, coating the waterproof and air-insulating glue from Preparation Example 1 on the surface of the substrate, the coating wet weight of the waterproof and air-insulating glue is 30g / m2, drying, the drying temperature is 120°C, and the speed is 60m / min to form a waterproof and air-insulating layer to obtain a waterproof and air-insulating composite film; S2, pressing the kraft paper and the waterproof and air-tight composite film at a pressing temperature of 140° C. and a pressing pressure of 12 MPa, so that the kraft paper and the waterproof and air-tight layer adhere to each other to obtain a kraft paper composite film; S3, tear off the substrate layer; S4. Apply the heat-sealing glue from Preparation Example 4 on the surface of the waterproof and air-barrier layer. The coating wet weight of the heat-sealing glue is 5 g / m2. The drying temperature is 120°C and the speed is 20 m / min. Dry and obtain a paper protective inflatable bubble bag composite film.

[0046] The difference between Example 2-3 and Example 1 is that the experimental parameters for preparing the paper protective inflatable bubble bag composite film are different. The specific differences are shown in Table 3: Table 3 Experimental parameters for preparing paper protective inflatable bubble bag composite film in Example 1-3 Example 4 A paper protective inflatable bubble bag composite film. The difference between this embodiment and embodiment 1 is that the waterproof and air-barrier glue comes from preparation example 2, and the heat-sealing glue comes from preparation example 5.

[0047] Example 5 A paper protective inflatable bubble bag composite film. The difference between this embodiment and embodiment 1 is that the waterproof and air-barrier glue comes from preparation example 3, and the heat-sealing glue comes from preparation example 6.

[0048] Example 6 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that the heat sealing glue is commercially available.

[0049] The heat sealing glue was purchased from Dongguan Yongshengfa Plastic Co., Ltd. and the brand is Dow EAA3003.

[0050] Example 7 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that before step S4, polyurethane glue is coated on the surface of the waterproof and air-barrier layer, and dried to obtain a polyurethane composite film, and the coating wet weight of the polyurethane glue is 10g / m 2 .

[0051] The polyurethane glue was purchased from Shanghai Bolino New Material Technology Co., Ltd., model number 5715B.

[0052] Example 8 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that before step S4, polyurethane glue is coated on the surface of the waterproof and air-barrier layer, and dried to obtain a polyurethane composite film, and the coating wet weight of the polyurethane glue is 15g / m 2 .

[0053] The polyurethane glue was purchased from Shanghai Bolino New Material Technology Co., Ltd., model number 5715B.

[0054] Comparative Example Comparative Example 1 A paper protective inflatable bubble bag composite film, the difference between this comparative example and Example 1 is that step S1-3 is omitted and the waterproof and air-barrier adhesive prepared in Preparation Example 1 is directly coated on kraft paper.

[0055] Comparative Example 2 A paper protective inflatable bubble bag composite film. The difference between this comparative example and Example 1 is that in step S2, the pressing temperature is 130° C. and the pressing pressure is 12 MPa.

[0056] Comparative Example 3 A paper protective inflatable bubble bag composite film. The difference between this comparative example and Example 1 is that in step S2, the pressing temperature is 140° C. and the pressing pressure is 10 MPa.

[0057] Comparative Example 4 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that the waterproof and air-barrier glue comes from comparative preparation example 1.

[0058] Comparative Example 5 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that the waterproof and air-barrier glue comes from comparative preparation example 2.

[0059] Comparative Example 6 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that the waterproof and air-barrier glue comes from comparative preparation example 3.

[0060] Comparative Example 7 A paper protective inflatable bubble bag composite film, the difference between this embodiment and embodiment 1 is that the waterproof and air-barrier glue comes from comparative preparation example 4.

[0061] Detection method / test method GTR air flow rate test: Test according to GB / T 1038.

[0062] Water vapor barrier performance test: The water vapor transmission rate is tested according to GB / T1037-1988 "Test method for water vapor permeability of plastic film and sheet - Cup method".

[0063] Waterproof performance: The paper protective inflatable bubble bag composite films prepared in Examples 1-8 and Comparative Examples 1-7 were immersed in 50° C. water for 24 hours, taken out, dried, and observed whether the kraft paper and the waterproof air barrier layer were separated.

[0064] Sealing strength: Tested in accordance with national standard GB / T 38082-2019.

[0065] Separation test of waterproof and air-barrier layer and heat-sealing layer: The paper protective inflatable bubble bag composite films prepared in Examples 1-8 and Comparative Examples 1-7 were heat-sealed at 200°C. The heat-sealing layer would deform after heat-sealing, and some of them would cause the heat-sealing layer and the waterproof and air-barrier layer to separate. A magnifying glass with a magnification of 10 times was used to observe whether the waterproof and air-barrier layer and the heat-sealing layer were separated.

[0066] Tensile strength: Tested in accordance with GB / T1040.3-2006 "Determination of tensile properties of plastics". The better the tensile strength, the more durable the paper protective inflatable bubble bag composite film is. The experimental data are shown in Table 4: Table 4 Experimental data of Examples 1-8 and Comparative Examples 1-7 It can be seen from Examples 1-8 and Comparative Examples 1-7 in combination with Table 4 that the paper protective inflatable bubble bag composite film prepared by the formulation and process in the present application has good waterproof and air-tight properties.

[0067] By comparing Example 1 with Comparative Example 1, the air permeability and water vapor permeability in Comparative Example 1 are much greater than those in Example 1, and the kraft paper and the waterproof vapor barrier layer are separated in the waterproof test. This shows that in the present application, by first coating the waterproof vapor barrier glue on the substrate to form a waterproof vapor barrier layer, and then pressing it with the kraft paper, the waterproof and vapor barrier properties of the paper protective inflatable bubble bag composite film can be greatly improved, while ensuring that the kraft paper and the waterproof vapor barrier layer are not easily separated.

[0068] Comparing Example 1 with Comparative Examples 2-3, the air permeability and water vapor permeability of Comparative Examples 2-3 are much greater than those of Example 1, and in the waterproof test, the kraft paper and the waterproof vapor barrier layer of Comparative Example 2 are separated, indicating that the waterproof and vapor barrier properties of the paper protective inflatable bubble bag composite film can be improved by optimizing the pressing temperature and parameters, while ensuring that the kraft paper and the waterproof vapor barrier layer are not easily separated.

[0069] By comparing Example 1 with Comparative Examples 4-7, the air permeability and water vapor permeability in Comparative Examples 4-7 are much greater than those in Example 1; in the waterproof test, the kraft paper and the waterproof air barrier layer of Comparative Examples 4 and 7 are separated; in the separation test of the waterproof air barrier layer and the heat sealing layer, separation occurs in Comparative Examples 4-5, indicating that the present application prepares a waterproof and air-barrier glue using polyvinyl alcohol, polyurethane-modified silicone, water-soluble chitosan, water-soluble acrylic resin, isooctyl acrylate, a cross-linking agent, ethanol and water, thereby effectively improving the waterproof and air-barrier properties of the paper protective inflatable bubble bag composite film, and at the same time, it can also improve the connection stability between the waterproof barrier layer and the kraft paper, and the connection stability between the waterproof and air-barrier layer and the heat sealing layer.

[0070] By comparing Example 1 with Example 6, in the separation test of the waterproof and air-barrier layer and the heat-sealing layer, separation occurs in Example 6, indicating that the heat-sealing glue prepared in the present application has good connection stability with the waterproof and air-barrier layer.

[0071] Comparing Example 1 with Example 7-8, the tensile strength of Example 7-8 is increased by 5.6 MPa, indicating that the tensile strength of the paper protective inflatable bubble bag composite film can be increased by adding a polyurethane layer in the present application.

[0072] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A process for preparing a composite film of a paper protective inflatable bubble bag, characterized in that: The method comprises the following preparation steps: S1, coating a waterproof and air-proof glue on the surface of the substrate, drying, forming a waterproof and air-proof layer, and obtaining a waterproof and air-proof composite film, wherein the waterproof and air-proof glue is prepared by mixing polyvinyl alcohol, polyurethane-modified silicone, water-soluble chitosan, water-soluble acrylic resin, isooctyl acrylate, a cross-linking agent, ethanol, and water; S2, pressing the kraft paper and the waterproof and air-tight composite film at a pressing temperature of 140-150° C. and a pressing pressure of 12-16 MPa, so that the kraft paper and the waterproof and air-tight layer adhere to each other to obtain a kraft paper composite film; S3, tear off the substrate layer; S4. Apply heat-sealing glue on the surface of the waterproof and air-barrier layer, and dry it to obtain a paper protective inflatable bubble bag composite film.

2. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 1, characterized in that: The weight percentages of the raw materials used to prepare the waterproof and airtight glue are as follows: Polyvinyl alcohol 10-20% Polyurethane modified silicone 5-8% Water-soluble chitosan 3-4% Water-soluble acrylic resin 10-15% 2-Ethylhexyl acrylate 10-15% Crosslinking agent 0.5-1% Ethanol 15-25% The balance is water.

3. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 2, characterized in that: The waterproof and air-isolating glue is prepared by the following method: Mix water and ethanol, then add water-soluble chitosan, water-soluble acrylic resin and polyvinyl alcohol, stir until all are dissolved, then add polyurethane-modified silicone, isooctyl acrylate and a cross-linking agent and stir evenly to obtain a waterproof and air-tight glue.

4. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 1, characterized in that: The coating weight of the waterproof and air-proof glue is 30-40g / m 2 .

5. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 1, characterized in that: The drying temperature in step S1 is 120-130° C. and the drying speed is 60-70 m / min.

6. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 1, characterized in that: The heat-sealing glue is prepared from the following raw materials in percentage by weight: Polyvinyl alcohol 15-20% Polyurethane modified silicone 5-8% Ethylene-vinyl acetate copolymer emulsion 5-9% Curing agent 0.5-1% Ethanol 10-20% The balance is water.

7. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 6, characterized in that: The coating weight of the heat seal glue is 5-10g / m 2 .

8. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 1, characterized in that: Before step S4, polyurethane glue is coated on the surface of the waterproof and air-barrier layer and dried to obtain a polyurethane composite film.

9. The process for preparing a composite film of a paper protective inflatable bubble bag according to claim 1, characterized in that: The coating wet weight of the polyurethane glue is 10-15g / m 2 .

10. A paper protective inflatable bubble bag composite film prepared by the paper protective inflatable bubble bag composite film preparation process according to any one of claims 1 to 9, characterized in that: The paper protective inflatable bubble bag composite film is prepared by the paper protective inflatable bubble bag composite film preparation process described in any one of claims 1-9.

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