A degradable instant foamable film and methods of making and using the same

Abstract

The present application relates to the technical field of foamed material (IPC classification number is C08J5 / 18), and more particularly to a degradable instant foaming film and a preparation method and use method thereof, according to weight parts, the preparation raw materials of the foaming film include: a) 10-20 parts of first degradation material; b) 15-25 parts of second degradation material; c) 40-70 parts of third degradation material; d) 10-20 parts of nucleating agent; e) 0.05-0.3 parts of lubricant; the melt index of the first degradation material is 1-4 g / 10 min, the melt index of the second degradation material is 0.5-2 g / 10 min, and the melt index of the third degradation material is 1-4 g / 10 min.The core feature of the present application is instant foaming when used and stable storage state when not used, which not only guarantees excellent buffering effect of the product, but also perfectly solves the problems of large transportation volume, high transportation cost, large storage space, large investment in foaming equipment, production risk and the like of the foaming packaging material, and is the first single-component biodegradable material capable of realizing normal-temperature instant foaming without pressure boosting in the prior art.

Description

Technical Field

[0001] The present invention relates to the technical field of foaming materials (IPC classification number is C08J5 / 18), and in particular to a degradable instant foaming film and a preparation method and a use method thereof. Background Art

[0002] Foam is a new type of packaging material that reduces and absorbs vibrations and is widely used in logistics, transportation, and product packaging. Existing foam packaging materials include sponge, pearl cotton, and polystyrene. These materials all share the common characteristic of being foamed before use. Pearl cotton, primarily made from high-pressure, low-density polyethylene, offers excellent flexibility and elasticity, unlike the fragility and poor resilience of foamed plastic. Polystyrene, formed by adding a blowing agent to polystyrene and foaming it at high temperatures, is lightweight, heat-insulating, sound-absorbing, shock-resistant, and corrosion-resistant. It is widely used for insulation, soundproofing, packaging, and vehicle and ship hulls.

[0003] The biggest pain point of current market demand is that foam materials are light in weight but bulky, requiring a large amount of space for storage and being extremely inconvenient to transport. The cost of storage and transportation even exceeds the cost of production. Chinese patent CN113308016B discloses a foaming film based on composite antibacterial nanomaterials and a method for preparing the same, comprising a step of modifying polylactic acid, a step of preparing a premix, a step of extrusion granulation, and a step of foaming film. The foaming film prepared has a porous structure, but still cannot solve the problem of being bulky and difficult to store and transport. There is no product in the prior art that can fully realize the process of rolling up and storing when not in use and foaming on site when in use. Therefore, developing a foaming film that can achieve instant foaming has extremely high application value. Summary of the Invention

[0004] The first aspect of the present invention provides a degradable instant foaming film, wherein the raw materials for preparing the foaming film include, by weight:

[0005] a) 10-20 parts of the first degradation material;

[0006] b) 15-25 parts of a second degradation material;

[0007] c) 40-70 parts of a third degradation material;

[0008] d) 10-20 parts of a nucleating agent;

[0009] e) 0.05-0.3 parts of lubricant;

[0010] The melt index of the first degradation material is 1-4 g / 10 min, the melt index of the second degradation material is 0.5-2 g / 10 min, and the melt index of the third degradation material is 1-4 g / 10 min.

[0011] Furthermore, the relative molecular mass of the first degradation material is 40,000-60,000, the relative molecular mass of the second degradation material is 60,000-80,000, and the relative molecular mass of the third degradation material is 60,000-80,000.

[0012] The present invention uses materials with high molecular weight and low melting point. It is found that the combination of specific melting point and molecular weight can reduce the degradation rate of the foam film and increase the shelf life. On the other hand, the low melting point material can provide greater melt strength, which meets the requirements of the high blow-up ratio film blowing process. However, the present invention does not require that the lower the melting point, the better. If the melting point is too low, the fluidity will be too poor, which will increase the extrusion back pressure and production temperature of the machine, increase the shear temperature of the foam film, and further increase the degradation rate. If the melting point is too high, the stability of the bubble will deteriorate. Under high blow-up ratio conditions, problems such as unstable bubble, uneven thickness, and wrinkles will occur. After repeated exploration, it was found that only the melting point range of 0.5-4g / 10min can maintain good melt strength and is conducive to plasticization.

[0013] Furthermore, the melt index of the first degradation material is 1-2 g / 10 min, the melt index of the second degradation material is 0.5-1 g / 10 min, and the melt index of the third degradation material is 1-2 g / 10 min.

[0014] The test conditions for the melt index described in the present invention are all 190°C / 2.16kg.

[0015] In some embodiments, the first degradation material, the second degradation material, and the third degradation material are each independently selected from at least one of PPC, PBAT, PLA, PGA, PHA, PHB, PVA, PEC, PLC, PBS, PHBV, PBSA, and PPDO.

[0016] In order to improve the film blowing properties, the first degradation material, the second degradation material, and the third degradation material are each independently selected from at least one of PPC, PBAT, PLA, PGA, and PHA, preferably at least one of PPC, PBAT, and PLA. Most preferably, the first degradation material is PLA, preferably sourced from NatureWorks in the United States, with a brand name of 4060; the second degradation material is PBAT, preferably sourced from Tunhe, Xinjiang, with a brand name of 801T; and the third degradation material is PPC, preferably sourced from Broad Oriental, with a brand name of T1.

[0017] PPC has good barrier properties, but also high viscosity and slow crystallization. The applicant discovered that by mixing PPC, PBAT, and PLA in specific ratios, rapid cooling and crystallization can be achieved within this system. The resulting material exhibits excellent film blowing properties, especially at a blow-up ratio of 2.8-3.5. Generally, greater transverse tensile strength results in poorer bubble stability. However, the coordinated combination of these three plastics allows for significant transverse stretch at blow-up ratios far exceeding existing technologies, resulting in exceptionally strong film blowing performance.

[0018] In some embodiments, the moisture content of the nucleating agent is not higher than 0.4%.

[0019] In some embodiments, the fineness of the nucleating agent is 2500-3500 mesh.

[0020] Furthermore, the nucleating agent includes at least one of talc, calcium carbonate, titanium dioxide, barium sulfate, ultra-high molecular weight polyethylene, potassium hydrogen phthalate, benzoic acid compounds, sodium benzoate compounds, and disodium bicyclo[2.2.1]heptane-2,3-dicarboxylate.

[0021] The nucleating agent is preferably talc, preferably sourced from Iroko, brand T3000, with a whiteness of 97% and a fineness of 3000 mesh. The addition of talc with a specific particle size can improve the processing performance of the material, reduce resistance in the twin-screw extruder and subsequent film blowing machine, lower processing temperatures, and minimize degradation in the subsequent modification process, thereby increasing production capacity. Furthermore, the applicants unexpectedly discovered that talc can increase the crystallization rate of the material, enhance the barrier properties of the film, and particularly reduce the viscosity of the PPC film after film formation. A specific particle size can increase the smoothness of the film; either too large or too small a particle size will result in a rougher film, making it less easily processed.

[0022] In some embodiments, the lubricant includes at least one of oleamide, mesic acid amide, zinc stearate, ethylene bisstearamide, polyethylene wax, and pentaerythritol stearate.

[0023] Considering economic benefits and system compatibility, the lubricant of the present invention is preferably oleamide.

[0024] A second aspect of the present invention provides a method for preparing a degradable instant foaming film, the method comprising the following steps:

[0025] S1. Preheat the mixer, add nucleating agent and lubricant by weight, and mix for 3-10 minutes;

[0026] S2. Continue to add the first degradation material, the second degradation material, and the third degradation material by weight, set the temperature to 80±5°C, heat and mix for 3-10min to obtain a mixture;

[0027] S3. The mixture is put into a hopper, heated and stirred to obtain a modified material;

[0028] S4. The modified material is cooled after being pulled, pelletized, homogenized, and packaged to obtain a pre-foamed material;

[0029] S5. The pre-foamed material is put into a single-screw film blowing machine, heated and blown to obtain a foam film;

[0030] S6. After the foam film is left to stand at room temperature, it is used for instant foaming.

[0031] In some embodiments, the temperature of the heating and stirring in S3 is set as follows:

[0032] Feeding section: 70-80℃;

[0033] Heating section 1: 120-130°C;

[0034] Heating sections 2-6: 140-150°C;

[0035] Extrusion section: 110-130℃;

[0036] Die head: 110-130℃.

[0037] The temperature setting of the heating and stirring in the further S3 is as follows:

[0038] Feeding section: 80℃;

[0039] Heating section 1: 120-130°C;

[0040] Heating section 2-6: 150°C;

[0041] Extrusion section: 120℃;

[0042] Die head: 120℃.

[0043] In some embodiments, the cooling method in S4 is to place the modified material strips in 0-5°C ice water.

[0044] The PPC material cools very slowly but easily absorbs water. In order to improve the cooling efficiency and minimize the water absorption of PPC, the modified material strip is placed in 0-5°C ice water for 1-2 seconds.

[0045] In some embodiments, the temperature of the S5 heated film blowing is set as follows:

[0046] Feeding section: 110-130℃;

[0047] Heating sections 1-6: 150-160°C;

[0048] Extrusion section: 150-160℃;

[0049] Die head: 130-150℃.

[0050] Furthermore, the temperature of the S5 heating film blowing is set as follows:

[0051] Feeding section: 120℃;

[0052] Heating section 1-6: 155°C;

[0053] Extrusion section: 155℃;

[0054] Die head: 140℃.

[0055] By setting two specific film blowing temperatures and process settings, the present invention does not require the addition of a compatibilizer and can also achieve a good compatibility effect.

[0056] In some embodiments, the blow-up ratio of the single-screw film blowing machine in S5 is 2.8-3.5.

[0057] In some embodiments, the blow-up ratio is increased in the S5 heated film blowing, thereby increasing the transverse tensile orientation of the material. The blow-up ratio is one of the key control points of the blow molding process. If the blow-up ratio is too small, the performance strength of the film in the transverse direction will deteriorate. If the blow-up ratio is too high, the precision requirements for the machine and the melt strength of the material are very high, and the cost and material selection are easily restricted. In this field, the blow-up ratio is usually 1.2-2.4. In the present invention, the blow-up ratio is limited to 2.8-3.5. At the same time, the winding speed is increased from the normal 20-25m / min to 35-40m / min, which greatly improves the biaxial tensile orientation of the material in the transverse and longitudinal directions compared with the normal film blowing process. On the one hand, the overall tensile strength of the material is improved. On the other hand, the biaxial stretching greatly improves the compatibility between materials. The most direct manifestation is the appearance transparency and trouser-type strength of the film.

[0058] The third aspect of the present invention provides a method for using a degradable instant foaming film, wherein foam glue is coated in the interlayer of two foaming films, the four sides are sealed, and the semi-finished product is rolled up. When in use, the semi-finished product is heated to achieve foaming.

[0059] Compared with the prior art, the present invention has the following beneficial effects:

[0060] 1. The core feature of this invention is its single-component biodegradable material, which foams instantly when in use and maintains a stable, high-density, low-volume state when not in use. This ensures the product's excellent cushioning effect while also addressing the issues of bulky, high freight costs, large storage space, and the high investment and production risks associated with foam packaging materials. This is the first single-component biodegradable material in the art that can achieve instant foaming at room temperature without the need for pressurization.

[0061] 2. The preparation material of the present invention does not contain compatibilizers or chain extenders. The raw materials are simple and easy to obtain, and the cost is low. However, through a specific film blowing process, the film blowing effect of adding compatibilizers and chain extenders can also be achieved. It is the first blown film product in the existing technology that does not contain compatibilizers.

[0062] 3. The prepared material of the present invention has excellent mechanical properties under the conditions of high blowing ratio and greater transverse stretching, good cushioning effect, and is not easy to break. It can completely replace the products such as polystyrene, pearl cotton, bubble film, etc. in the existing technology that are large in volume and difficult to transport. After preparation and rolling, it occupies extremely small space, has extremely high transportation and storage efficiency, and significantly reduces costs.

[0063] 4. The preparation process of the present invention innovatively adopts a cold water cooling method, which solves the problems of long cooling stroke and high cost of air cooling equipment and water cooling causing water absorption, granulation and foaming of the modified material. The conventional water cooling stroke is only 1 / 10 of that of air cooling, while the ice cooling stroke of the present invention is only 1 / 4 of that of conventional water cooling and 1 / 40 of that of air cooling. The contact time with water is short, and the material can be packaged after drying in the homogenization bin.

[0064] 5. The preparation material of the present invention, combined with the preparation process, can effectively improve the preparation efficiency, and the production capacity is increased from 20m / min in the existing technology to 35m / min, bringing extremely high economic benefits to the enterprise. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is the foam film prepared in Example 3.

[0066] Figure 2 This is the foam film prepared in Comparative Example 4. DETAILED DESCRIPTION

[0067] Example 1

[0068] The first aspect of this embodiment provides a degradable instant foaming film. The raw materials for preparing the foaming film include, by weight:

[0069] a) 15 parts of the first degradation material;

[0070] b) 19.8 parts of a second degradation material;

[0071] c) 50 parts of a third degradation material;

[0072] d) 15 parts of a nucleating agent;

[0073] e) 0.2 parts of lubricant;

[0074] The first degradation material is PLA, with a melt index of 1-2g / 10min and a relative molecular mass of 40,000-60,000; the second degradation material is PBAT, with a melt index of 0.5-1g / 10min and a relative molecular mass of 60,000-80,000; and the third degradation material is PPC, with a melt index of 1-2g / 10min and a relative molecular mass of 60,000-80,000.

[0075] The nucleating agent is talcum powder with a whiteness of 97%, a fineness of 3000 meshes and a moisture content not higher than 0.4%.

[0076] The lubricant is oleamide.

[0077] A second aspect of this embodiment provides a method for preparing a degradable instant foaming film, the method comprising the following steps:

[0078] S1. Preheat the mixer to 85°C, add the nucleating agent and lubricant by weight, and mix for 5 minutes.

[0079] S2. Continue to add the first degradation material, the second degradation material, and the third degradation material by weight, heat and mix at 80°C ± 5 for 5 minutes to obtain a mixture;

[0080] S3. Put the mixed material into the hopper, heat and stir to obtain the modified material. The temperature is set as follows:

[0081] Feeding section: 80℃;

[0082] Heating section 1: 125°C;

[0083] Heating section 2-6: 150°C;

[0084] Extrusion section: 120℃;

[0085] Die head: 120℃.

[0086] S4. The modified material was placed in ice water at 0°C for 2 seconds, pelletized, dried at 60°C for 30 minutes, homogenized, and packaged in nylon inner bags to obtain pre-foamed material;

[0087] S5. The pre-foamed material was fed into a single-screw film blowing machine with a blow-up ratio of 3.2, a longitudinal winding speed of 55 m / min, heated film blowing, and the temperature was set as follows to obtain a foam film;

[0088] Feeding section: 120℃;

[0089] Heating section 1-6: 155°C;

[0090] Extrusion section: 155℃;

[0091] Die head: 140℃;

[0092] S6. After the foam film is left to stand at room temperature for 7 days, it is cut into two foam films of the same shape and area by a slitting machine for instant foaming.

[0093] The third aspect of this embodiment provides a method for using a degradable instant foaming film, which comprises coating the interlayer of two foaming films with foam glue, sealing the four sides, and rolling up to obtain a semi-finished product. When in use, the semi-finished product can be heated to achieve foaming.

[0094] Example 2

[0095] The first aspect of this embodiment provides a degradable instant foaming film. The specific implementation is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the foaming film include:

[0096] a) 10 parts of the first degradation material;

[0097] b) 15 parts of a second degradation material;

[0098] c) 40 parts of a third degradation material;

[0099] d) 10 parts of a nucleating agent;

[0100] e) 0.05 parts of lubricant;

[0101] A second aspect of this embodiment provides a method for preparing a degradable instant foaming film, the method comprising the following steps:

[0102] S1. Preheat the mixer to 85°C, add the nucleating agent and lubricant by weight, and mix for 3 minutes;

[0103] S2. Continue to add the first degradation material, the second degradation material, and the third degradation material by weight, heat and mix at 80°C ± 5 for 3 minutes to obtain a mixture;

[0104] S3. Put the mixed material into the hopper, heat and stir to obtain the modified material. The temperature is set as follows:

[0105] Feeding section: 70℃;

[0106] Heating section 1: 120°C;

[0107] Heating section 2-6: 140°C;

[0108] Extrusion section: 110℃;

[0109] Die head: 110℃.

[0110] S4. The modified material was placed in ice water at 5°C for 1.5 seconds, pelletized, dried at 60°C for 30 minutes, homogenized, and packaged in nylon inner bags to obtain pre-foamed material.

[0111] S5. The pre-foamed material was fed into a single-screw film blowing machine with a blow-up ratio of 2.8, and the film was heated and the temperature was set as follows to obtain a foamed film;

[0112] Feeding section: 110℃;

[0113] Heating section 1-6: 150°C;

[0114] Extrusion section: 150℃;

[0115] Die head: 130℃;

[0116] S6. After the foam film is left to stand at room temperature for 7 days, it is cut into two foam films of the same shape and area by a slitting machine for instant foaming.

[0117] The third aspect of this embodiment provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0118] Example 3

[0119] The first aspect of this embodiment provides a degradable instant foaming film. The specific implementation is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the foaming film include:

[0120] a) 20 parts of the first degradation material;

[0121] b) 25 parts of a second degradation material;

[0122] c) 70 parts of a third degradation material;

[0123] d) 20 parts of a nucleating agent;

[0124] e) 0.3 parts of lubricant;

[0125] A second aspect of this embodiment provides a method for preparing a degradable instant foaming film, the method comprising the following steps:

[0126] S1. Preheat the mixer to 85°C, add the nucleating agent and lubricant by weight, and mix for 10 minutes.

[0127] S2. Continue to add the first degradation material, the second degradation material, and the third degradation material by weight, heat and mix at 80°C ± 5 for 10 minutes to obtain a mixture;

[0128] S3. Put the mixed material into the hopper, heat and stir to obtain the modified material. The temperature is set as follows:

[0129] Feeding section: 75℃;

[0130] Heating section 1: 130°C;

[0131] Heating section 2-6: 150°C;

[0132] Extrusion section: 130℃;

[0133] Die head: 130℃.

[0134] S4. The modified material was placed in ice water at 3°C ​​for 2 seconds, pelletized, dried at 60°C for 30 minutes, homogenized, and packaged in nylon inner bags to obtain pre-foamed material.

[0135] S5. The pre-foamed material was fed into a single-screw film blowing machine with a blow-up ratio of 3.5, and the film was heated and the temperature was set as follows to obtain a foamed film;

[0136] Feeding section: 130℃;

[0137] Heating section 1-6: 160°C;

[0138] Extrusion section: 160℃;

[0139] Die head: 150℃;

[0140] S6. After the foam film is left to stand at room temperature for 7 days, it is cut into two foam films of the same shape and area by a slitting machine for instant foaming.

[0141] The third aspect of this embodiment provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0142] Comparative Example 1

[0143] The first aspect of this comparative example provides a degradable instant foaming film, and the specific implementation manner is the same as that of Example 1, except that the third degradation material is PHA, which is purchased from Icoman.

[0144] The second aspect of this comparative example provides a method for preparing a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0145] The third aspect of this comparative example provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0146] Comparative Example 2

[0147] The first aspect of this comparative example provides a degradable instant foaming film, and the specific implementation method is the same as that of Example 1, except that the third degradation material is PGA, which is purchased from Huitong Technology.

[0148] The second aspect of this comparative example provides a method for preparing a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0149] The third aspect of this comparative example provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0150] Comparative Example 3

[0151] The first aspect of this comparative example provides a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0152] The second aspect of this comparative example provides a method for preparing a degradable instant foaming film. The specific implementation method is the same as that of Example 1, except that the blowing ratio is 2.0.

[0153] The third aspect of this comparative example provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0154] Comparative Example 4

[0155] The first aspect of this comparative example provides a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0156] The second aspect of this comparative example provides a method for preparing a degradable instant foaming film. The specific implementation method is the same as that of Example 1, except that the temperature in S5 is set as follows:

[0157] Feeding section: 100℃;

[0158] Heating section 1-6: 140°C;

[0159] Extrusion section: 140℃;

[0160] Die head: 120℃.

[0161] The third aspect of this comparative example provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0162] Comparative Example 5

[0163] The first aspect of this comparative example provides a degradable instant foaming film, and the specific implementation method is the same as that of Example 1, except that, in parts by weight, the raw materials for preparing the foaming film include:

[0164] a) 0 parts of the first degradation material;

[0165] b) 15 parts of a second degradation material;

[0166] c) 79.5 parts of a third degradation material;

[0167] d) 15 parts of a nucleating agent;

[0168] e) 0.05 parts of lubricant;

[0169] The second aspect of this comparative example provides a method for preparing a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0170] The third aspect of this comparative example provides a method for using a degradable instant foaming film, and the specific implementation method is the same as that of Example 1.

[0171] Performance Testing

[0172] Two pieces of foam films prepared in Examples 1-3 and Comparative Examples 1-4 were selected, and starch foam glue was circularly coated on the surface of the first piece with a coating weight of 80 g. Then, another piece of foam film was covered on the surface, and the four sides were heat-sealed. An electromagnetic microwave foaming film machine was used for foaming, and the microwave output power was 1000 w, the microwave frequency was 2.45 GHZ, and the heating time was 15 s.

[0173] The foaming glue and electromagnetic microwave foaming film-forming machine are both from Xiamen Aimeson New Materials Technology Co., Ltd.

[0174] The foamed film is subjected to the following performance tests:

[0175] Water permeability: test method refers to GB / T1037-1988;

[0176] Elongation at break: Test method refers to GB / T1040.3-2006;

[0177] Transverse tensile strength: test method refers to GB / T1040.3-2006;

[0178] Foaming effect: Refer to ASTM D3575 to test the film foaming density and calculate the expansion ratio;

[0179] Bake at 60℃ for one month before foaming: simulate the effect of water loss during storage and shipping, which may affect the foaming ratio.

[0180]

[0181]

[0182] In Comparative Examples 1 and 2, the PPC material was replaced with PHA and PGA, but due to their excessive rigidity, film blowing and molding were not possible during the experiment.

[0183] In Comparative Example 3, it was found that the tensile properties of the film decreased significantly after the blowing ratio was reduced, and the water vapor permeability also decreased significantly. This part of the performance is directly related to the tensile orientation of the material. The larger the blowing ratio, the higher the transverse tensile strength of the film and the better the barrier effect of the film.

[0184] In Comparative Example 4, it was found that after the film blowing temperature was lowered, a large number of crystal points and white lines appeared in the film. The PPC in the formula failed to be completely plasticized, resulting in poor film blowing uniformity and poor water barrier effect of the film. The water in the foaming glue was lost during baking, resulting in a significant decrease in the foaming ratio of the foaming material.

[0185] In Comparative Example 5, the PPC content was continuously increased to 80%. Since PPC is a non-crystalline material, it cannot be cooled quickly, resulting in the tube films directly adhering to each other after film blowing and being unable to be separated. Gluing and testing at the back end were impossible, and the result was judged as NG.

Claims

1. A method for preparing a degradable instant foaming film, characterized in that: The steps are as follows: S1. Preheat the mixer, add 10-20 parts by weight of nucleating agent and 0.05-0.3 parts of lubricant, and mix for 3-10 minutes; S2 continue to input 10-20 parts by weight of the first degradation material, 15-25 parts of the second degradation material, 40-70 parts of the third degradation material, heated and stirred for 3-10min to obtain a mixture; S3. The mixture is put into a hopper, heated and stirred to obtain a modified material; S4. The modified material is cooled after being pulled, pelletized, homogenized, and packaged to obtain a pre-foamed material; S5. The pre-foamed material is put into a single-screw film blowing machine, heated and blown to obtain a foam film; S6. After the foam film is left to stand at room temperature, it is used for instant foaming; The temperature setting of the S5 heating film blowing is as follows: Feeding section: 110-130℃; Heating sections 1-6: 150-160°C; Extrusion section: 150-160℃; Die head: 130-150℃; The blow-up ratio of the single-screw film blowing machine in S5 is 2.8-3.5; The first degradation material is PLA, with a melt index of 1-2g / 10min and a relative molecular mass of 40,000-60,000; the second degradation material is PBAT, with a melt index of 0.5-1g / 10min and a relative molecular mass of 60,000-80,000; and the third degradation material is PPC, with a melt index of 1-2g / 10min and a relative molecular mass of 60,000-80,000.

2. The method for preparing a degradable instant foaming film according to claim 1, wherein: The moisture content of the nucleating agent is not higher than 0.4%.

3. The method for preparing a degradable instant foaming film according to claim 1, wherein: The fineness of the nucleating agent is 2500-3500 mesh.

4. The method for preparing a degradable instant foaming film according to claim 1, wherein: The temperature setting of heating and stirring in S3 is as follows: Feeding section: 70-80℃; Heating section 1: 120-130°C; Heating sections 2-6: 140-150°C; Extrusion section: 110-130℃; Die head: 110-130℃.

5. The method for preparing a degradable instant foaming film according to claim 1, wherein: The cooling method in S4 is to place the modified material strips in 0-5°C water.

6. The method for preparing a degradable instant foaming film according to claim 1, wherein: The time for placing the modified material strip in 0-5°C water is 1-2 seconds.

7. A method for using the degradable instant foaming film prepared according to claims 1-6, characterized in that: After applying foam glue in the interlayer of two foam films, the four sides are sealed and rolled up to obtain a semi-finished product. When in use, the semi-finished product can be heated to achieve foaming.

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