Composite membrane cloth for air cushion and preparation method of composite membrane cloth

Abstract

The invention relates to the technical field of daily cosmetics, and particularly discloses composite membrane cloth for an air cushion and a preparation method of the composite membrane cloth. The invention relates to a composite film for an air cushion. The composite film is formed by laminating a knitted fabric and a PDMS (Polydimethylsiloxane) film, the knitted fabric is woven by elastic yarns and internally comprises a coil structure and a hole structure; the PDMS film is provided with a plurality of uniformly or non-uniformly distributed crack structures corresponding to the recesses of the adjacent coil structures of the knitted fabric; the preparation method comprises the following steps: mixing the raw materials for preparing the defoamed PDMS film, and coating on a substrate; then the knitted fabric is arranged on the PDMS film coating material to be attached, after drying, the attached knitted fabric and PDMS film are integrally stripped, and semi-finished product film cloth is obtained; and finally, stretching the semi-finished product film cloth, so that a crack structure appears on the PDMS film. When the composite membrane cloth for the air cushion is applied, liquid foundation is difficult to leak even in the processes of shaking, lateral placement and inversion, and the liquid foundation can be uniformly released, so that waste and pollution caused by leakage of the liquid foundation can be avoided.

Description

Technical Field

[0001] The present application relates to the technical field of daily cosmetics, and more specifically, to a composite membrane cloth for air cushions and a preparation method thereof. Background Art

[0002] In recent years, with the rapid development of the beauty and cosmetics industry, people have increasingly higher requirements for the texture, user experience and makeup effect of cosmetics. As a new type of cosmetics product, air cushion foundation has received widespread attention and popularity due to its lightness, portability and ease of use.

[0003] The mesh air cushion product is a common air cushion foundation. It uses mesh as the storage and distribution medium of the liquid foundation. It has more foundation capacity, is not easy to breed bacteria, is more hygienic, and has the advantages of light weight, long service life, and not easy to perforate.

[0004] In order to make the liquid foundation more breathable and moisturizing after being applied to the user's face, and to allow the liquid foundation to quickly seep out when the user presses the mesh, manufacturers often use foundation with lower viscosity and mesh with larger holes to produce mesh air cushions. However, during shaking, sideways and inversion, the liquid foundation easily leaks from the mesh, causing pollution and waste. Or in order to prevent the liquid foundation from penetrating when shaking, sideways and inverted, manufacturers will use foundation with higher viscosity and mesh with smaller holes to produce mesh air cushions, which are often accompanied by problems such as failure to discharge the material in time and uneven discharge when pressed, affecting the user experience.

[0005] Therefore, it is urgent to propose a solution to solve the above technical problems. Summary of the invention

[0006] In order to prevent the liquid foundation from leaking when the mesh air cushion is shaken, placed sideways or inverted, and to evenly release the liquid foundation when pressed, the present application provides a composite membrane cloth for an air cushion and a preparation method thereof.

[0007] In the first aspect, the present application provides a composite membrane cloth for an air cushion, which adopts the following technical solution: A composite membrane cloth for an air cushion, formed by laminating a knitted cloth (1) and a PDMS membrane (2); The knitted fabric (1) is woven from elastic yarn and contains a coil structure and a hole structure inside; The PDMS film (2) is provided with a plurality of evenly or unevenly distributed crack structures (3) at the concave portions of the adjacent coil structures of the knitted fabric (1).

[0008] By adopting the above technical scheme, the knitted fabric is woven from elastic yarn, which meets the requirements of pressing the composite membrane cloth for air cushion; and the coil structure and hole structure contained in it can not only stably store the liquid foundation, but also quickly and evenly release the liquid foundation. The PDMS membrane is formed by the cross-linking reaction of macromolecular polydimethylsiloxane, and its macromolecules easily form a large molecular gap, so that the PDMS membrane has a high air permeability and moisture permeability effect, and the surface energy of the PDMS membrane is low and the resilience is good, which can bring a better application experience. At the same time, the PDMS membrane is provided with a number of uniformly or unevenly distributed crack structures in the concave part of the adjacent coil structure of the knitted fabric, so that when the composite membrane cloth for air cushion is pressed, the crack structure is in an open state, and the liquid foundation can pass through the crack quickly and evenly, and when no external force is applied to the composite membrane cloth for air cushion, the crack structure is in a closed state, preventing the liquid foundation from leaking, even if the mesh air cushion is in the process of shaking, sideways and inverted, the liquid foundation is difficult to leak; in this way, waste and pollution caused by leakage of liquid foundation can be avoided, and the overall application effect is outstanding.

[0009] Preferably, the count of the elastic yarn used in the knitted fabric (1) is 30-150D, and the weaving structure of the knitted fabric (1) is a combination of one or more of rib structure, double rib structure, double reverse structure, tuck structure, furrow knit structure, half furrow knit structure, fat flower structure, rib warp plain structure, double rib warp plain structure, double warp plain structure, warp flat velvet structure, warp flat velvet structure, warp oblique flat structure, warp velvet chain structure, warp oblique chain structure and spacer structure.

[0010] By adopting the above technical solution, the elastic yarn of the above fineness and the above manufacturing structure, the obtained knitted fabric can be applied to the composite membrane fabric for air cushions and can stably play its role during the application process. Among them, the weaving structure of the knitted fabric is preferably a rib structure, which can make the crack structure on the PDMS film of the composite membrane fabric for air cushions more uniform and more matched with the concave part of the adjacent coil structure during the stretching process of the composite membrane fabric for air cushions.

[0011] Preferably, the elastic yarn is spandex yarn or spandex blended yarn, and the spandex blended yarn is blended with spandex and one or more of polyester, nylon, acrylic, modal fiber, acetate fiber, viscose fiber, cupro fiber, and cotton fiber.

[0012] By adopting the above technical solution, spandex, also known as elastic fiber or Lycra fiber, is a synthetic fiber composed of polyurethane, which has excellent elasticity and extensibility, and a high elastic recovery rate. It can be well extended when subjected to external force, and quickly recover to its original shape when the external force is removed; and spandex also has the advantages of not easy to wrinkle, durable and not easy to age, stable chemical properties, and high biocompatibility. It is used as a necessary raw material for knitted elastic yarn, so that the overall application effect of the obtained composite membrane cloth for air cushion is better. At the same time, in the application of spandex blended yarn, in order to ensure the excellent embodiment of the above effects, the spandex content is at least 10%.

[0013] Preferably, the elasticity of the knitted fabric (1) is higher than that of the PDMS film (2), and the elastic recovery rate of the knitted fabric (1) is greater than 90%.

[0014] By adopting the above technical scheme, during the stretching treatment of the composite membrane cloth for air cushions, the elasticity of the knitted fabric is made higher than that of the PDMS film, and the elastic recovery rate of the knitted fabric is greater than 90%. While a crack structure can be formed on the PDMS film, the structural stability of the knitted fabric is not affected. At the same time, the integrity and tensile properties of the composite membrane cloth for air cushions are basically the same after rebound.

[0015] Preferably, the knitted fabric (1) has a thickness of 0.3-1 mm and a weight of 80-300 g / m 2 .

[0016] By adopting the above technical scheme, according to the actual application requirements of the composite membrane cloth for air cushion, if the thickness and gram weight of the knitted fabric are lower than the above range, the liquid foundation will easily leak; if the thickness and gram weight of the knitted fabric are higher than the above range, the liquid foundation will be discharged slowly, affecting the user experience; and the selection of the above thickness and gram weight of the knitted fabric makes the composite membrane cloth for air cushion have a stable and better application effect, not only is it not easy for the liquid foundation to leak during shaking, sideways and inverted, but it can also release the liquid foundation evenly when pressed.

[0017] Preferably, the PDMS membrane (2) is made of the following raw materials in parts by weight: Dow Corning SYLGARD 184PDMS basic component 8-12 parts; Dow Corning SYLGARD 184 cross-linking curing agent 0.8-1.2 parts.

[0018] By adopting the above technical solution, the basic components of Dow Corning SYLGARD 184 PDMS and the cross-linking curing agent of Dow Corning SYLGARD 184 can be mixed within the above dosage range and can be used. The overall application is relatively convenient, and no adhesive is required in the process of combining with the knitted fabric. At the same time, after being compounded with the knitted fabric, the obtained composite membrane cloth for the air cushion also has a better overall feel.

[0019] Preferably, the thickness of the PDMS film (2) is 0.05-0.5 mm.

[0020] By adopting the above technical scheme, the thickness of the PDMS film has a significant influence on the stabilizing effect of the crack structure thereon. If the thickness of the PDMS film is lower than the above range, leakage of the liquid foundation is likely to occur. If the thickness of the PDMS film is higher than the above range, the crack structure cannot be fully opened when the composite membrane cloth for the air cushion is subjected to normal extrusion, which will affect the discharge speed and uniformity of the liquid foundation. By selecting the PDMS film thickness within the above range, the composite membrane cloth for the air cushion obtained can have a stable and excellent application effect.

[0021] In a second aspect, the present application provides a method for preparing a composite membrane cloth for an air cushion, using the following technical solution: A method for preparing a composite membrane cloth for an air cushion, comprising the following steps: S1, mixing the raw materials used for preparing the degassed PDMS membrane (2) and coating the mixture on a substrate; S2, placing the knitted fabric (1) on the PDMS membrane (2) coating material for bonding, and after drying, peeling off the bonded knitted fabric (1) and the PDMS membrane (2) as a whole to obtain a semi-finished membrane fabric; S3, stretching the semi-finished membrane cloth obtained after peeling to make a crack structure appear on the PDMS membrane (2), thus obtaining a composite membrane cloth for air cushion.

[0022] By adopting the above technical scheme, the above preparation method is simple to operate and is convenient for quality control during the process, especially in the molding of the PDMS film and the formation of the crack structure on the PDMS film. It is also more convenient and not only suitable for large-scale industrial production of composite membrane cloth for air cushions, but also can obtain composite membrane cloth for air cushions with excellent quality.

[0023] Preferably, in the operation of step S2, the drying temperature is 60-100° C., and the drying time is 1-12 h.

[0024] By adopting the above technical solution and controlling the above temperature and time, the PDMS membrane-coated fabric not only has a better bonding effect with the knitted fabric after molding, but also can make the obtained composite membrane fabric for air cushion have excellent integrity when crack structure appears in the subsequent stretching treatment.

[0025] Preferably, in the operation of step S3, the stretching treatment method is: stretching the knitted fabric (1) transversely by 100-250% along the stripe direction until more than 70% of the PDMS membranes (2) corresponding to the adjacent coil recesses of the knitted fabric (1) have uniform or non-uniform crack structures.

[0026] By adopting the above technical scheme and selecting the above stretching treatment method, it is easier to form a crack structure on the PDMS membrane in the concave parts of the adjacent coil structures of the knitted fabric, thereby effectively regulating the release of liquid foundation through the crack structure; at the same time, the crack structure is limited to more than 70% so that when the composite membrane cloth for air cushion is subjected to normal compression, the crack structure can open to quickly and evenly release the foundation, thereby ensuring that the composite membrane cloth for air cushion has a better application effect.

[0027] In summary, this application has the following beneficial effects: The present application laminates knitted fabric and PDMS membrane as a composite membrane fabric for air cushion, and provides a plurality of evenly or unevenly distributed crack structures at the concave portion of the PDMS membrane corresponding to the adjacent coil structure of the knitted fabric (1). When the composite membrane fabric for air cushion is pressed, the crack structures are in an open state, and liquid foundation can pass through the cracks quickly and evenly. When no external force is applied to the composite membrane fabric for air cushion, the crack structures are in a closed state. Even if the mesh air cushion is shaken, placed sideways or inverted, it is difficult for liquid foundation to leak, thereby avoiding waste and pollution caused by leakage of liquid foundation. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the cross-sectional layered structure of the composite membrane cloth for air cushion in Example 1 of the present application; Figure 2 This is a schematic diagram of the weaving structure of the composite membrane cloth for the air cushion in Example 1 of the present application; Figure 3 This is a perspective structural diagram of the composite membrane cloth for air cushion in an unstretched state in Example 1 of the present application; Figure 4 It is a perspective structural schematic diagram of the composite membrane cloth for air cushion in stretched state in Example 1 of the present application.

[0029] Description of the accompanying drawings: 1. Knitted fabric; 2. PDMS membrane; 3. Crack structure. DETAILED DESCRIPTION

[0030] The present application is further described in detail below with reference to the accompanying drawings and embodiments. Example

[0031] Example 1 A composite membrane cloth for air cushion, such as Figure 1 As shown, it is formed by laminating a knitted fabric 1 and a PDMS membrane 2; Figure 2 As shown, the knitted fabric 1 is woven from elastic yarn, and contains a coil structure and a hole structure inside, and the PDMS membrane 2 is provided with a plurality of crack structures 3 corresponding to the concave portions of the adjacent coil structures of the knitted fabric 1, and the crack structures 3 can be evenly distributed or unevenly distributed. Figure 3As shown, when no external force is applied to the composite membrane cloth for the air cushion, the crack structure 3 is in a closed state, preventing the liquid foundation from leaking. Even if the mesh air cushion is in the process of shaking, sideways or inverted, the liquid foundation is unlikely to leak. Figure 4 As shown, when the composite membrane cloth for air cushion is pressed, the crack structure 3 is in an open state, and the foundation liquid can pass through the cracks quickly and evenly. Meanwhile, the composite membrane cloth for air cushion is prepared by the following steps: S1. Mix the raw materials used for preparing the degassed PDMS membrane and apply 0.25 mm of the mixture on a glass substrate using a scraper; S2, laminating the knitted fabric on the PDMS membrane coated material, and after drying, peeling off the laminated knitted fabric and PDMS membrane as a whole to obtain a semi-finished membrane fabric; S3. The semi-finished membrane cloth obtained after peeling is stretched to make a crack structure appear on the PDMS membrane, thereby obtaining a composite membrane cloth for an air cushion.

[0032] Note: The raw materials used for the preparation of PDMS membrane consist of 10 parts (parts / kg) of Dow Corning SYLGARD 184 PDMS basic component and 1 part (parts / kg) of Dow Corning SYLGARD 184 cross-linking curing agent; the thickness of the knitted fabric is 0.65 mm and the weight is 190 g / m 2 The elastic yarn count is 90D, 82% nylon / 18% spandex blended yarn is used as the elastic yarn, the weaving structure is a rib structure, and the elasticity of the knitted fabric is tested to be higher than that of the PDMS membrane, and the elastic recovery rate of the knitted fabric is greater than 90%; in the operation of step S2, the drying temperature is 80°C and the drying time is 6.5h; in the operation of step S3, the stretching treatment method is: transversely stretching the knitted fabric (1) by 175% along the stripe direction until more than 70% of the PDMS membrane (2) corresponding to the concave parts of the adjacent coil structures of the knitted fabric (1) have crack structures, which is 74.5% in this embodiment.

[0033] Example 2 A composite membrane cloth for an air cushion, which is different from Example 1 in that the raw materials used to prepare the PDMS membrane consist of 8 parts (parts / kg) of Dow Corning SYLGARD 184 PDMS basic component and 1.2 parts (parts / kg) of Dow Corning SYLGARD 184 cross-linking curing agent.

[0034] Example 3 A composite membrane cloth for an air cushion, which is different from Example 1 in that the raw materials used to prepare the PDMS membrane consist of 12 parts (parts / kg) of Dow Corning SYLGARD 184 PDMS basic component and 0.8 parts (parts / kg) of Dow Corning SYLGARD 184 cross-linking curing agent.

[0035] Example 4 A composite membrane cloth for air cushion, which is different from Example 1 in that the knitted cloth has a thickness of 0.3 mm and a gram weight of 80 g / m 2 .

[0036] Example 5 A composite membrane cloth for air cushion, which is different from Example 1 in that the knitted cloth has a thickness of 1 mm and a gram weight of 300 g / m 2 .

[0037] Example 6 A composite membrane cloth for an air cushion, which is different from Example 1 in that the thickness of the PDMS membrane is 0.05 mm.

[0038] Example 7 A composite membrane cloth for an air cushion, which is different from Example 1 in that the thickness of the PDMS membrane is 0.5 mm.

[0039] Example 8 A composite membrane cloth for an air cushion, which is different from Example 1 in that the count of the elastic yarn is 30D, and 82% nylon / 18% spandex blended yarn is used as the elastic yarn.

[0040] Example 9 A composite membrane cloth for an air cushion, which is different from Example 1 in that the count of the elastic yarn is 150D, and 82% nylon / 18% spandex blended yarn is used as the elastic yarn.

[0041] Example 10 A composite membrane cloth for an air cushion, which is different from Example 1 in that 100% spandex yarn is used as the elastic yarn.

[0042] Embodiment 11 A composite membrane cloth for an air cushion, which is different from Example 1 in that 70% polyester / 30% spandex blended yarn is used as the elastic yarn.

[0043] Example 12 A composite membrane cloth for an air cushion, which is different from Example 1 in that, in the operation of step S2, the drying temperature is 60° C. and the drying time is 12 hours.

[0044] Example 13 A composite membrane cloth for an air cushion, which is different from Example 1 in that, in the operation of step S2, the drying temperature is 100° C. and the drying time is 1 hour.

[0045] Embodiment 14 A composite membrane cloth for air cushion, which is different from Example 1 in that, in the operation of step S3, the stretching treatment method is: 100% transverse stretching along the stripe direction of the knitted cloth, until more than 70% of the PDMS membranes corresponding to the concave parts of the adjacent coil structures of the knitted cloth have crack structures.

[0046] Embodiment 15 A composite membrane cloth for air cushions, which differs from Example 1 in that, in the operation of step S3, the stretching treatment method is: stretching the knitted cloth (1) transversely by 250% along the stripe direction, until crack structures appear in the PDMS membranes corresponding to the concave parts of the adjacent coil structures of more than 70% of the knitted cloths.

[0047] Example 16 A composite membrane cloth for air cushion, which is different from Example 1 in that the thickness of the knitted cloth is 0.2 mm and the weight is 70 g / m 2 .

[0048] Embodiment 17 A composite membrane cloth for air cushion, which is different from Example 1 in that the thickness of the knitted cloth is 1.1 mm and the weight is 310 g / m 2 .

[0049] Embodiment 18 A composite membrane cloth for an air cushion, which is different from Example 1 in that the thickness of the PDMS membrane (2) is 0.04 mm.

[0050] Embodiment 19 A composite membrane cloth for an air cushion, which is different from Example 1 in that the thickness of the PDMS membrane (2) is 0.55 mm.

[0051] Embodiment 20 A composite membrane cloth for air cushions, which is different from Example 1 in that, in the stretching operation of step S3, crack structures appear in the PDMS membranes corresponding to the concave parts of the adjacent coil structures of no more than 70% of the knitted cloths, which is 68.5% in this example.

[0052] Performance testing Test sample: The composite membrane cloth for air cushion obtained in Example 1-20 was used as test sample 1-20.

[0053] Test method: The commercially available Lancome Absolu Essence Liquid Foundation was used as the test liquid foundation, which was combined with test samples 1-20 respectively to obtain 20 kinds of air cushion foundation products.

[0054] (1) Shaking, sideways and inverted test: Press the composite membrane cloth for the air cushion to absorb the liquid foundation and then shake, sideways and invert it. The shaking amplitude is 15 degrees and the sideways angle is 45 degrees. Observe whether there is any leakage of liquid foundation. The same test is completed for 20 air cushion foundation products in turn.

[0055] (2) Liquid foundation uniformity test: By observing the distribution of the air cushion foundation on the skin, its uniformity can be preliminarily judged. The specific operation can be to invite 2 volunteers with dry skin and oily skin to use test samples 1-20 in turn, wash their faces with facial cleanser and water before use to ensure that the face is clean, and carefully observe the surface of the skin after use to see if there is obvious color difference or mottled phenomenon. If the color of the skin surface is uniform, without obvious color blocks or color differences, then it can be considered that the liquid foundation is distributed relatively evenly.

[0056] Table 1 Application test results of experimental samples 1-20 It can be seen from Example 1 and Example 2-3 and Table 1 that after the Dow Corning SYLGARD 184 PDMS basic component and the Dow Corning SYLGARD 184 cross-linking curing agent are mixed to prepare the PDMS film, the obtained composite membrane cloth for air cushion can show a stable application effect. In the presence of the crack structure, when the crack structure is closed, even if it is shaken, placed sideways and inverted, the foundation liquid is difficult to leak, and when the crack structure is in an open state, the foundation liquid can also pass through the crack quickly and evenly. After testing, there is no obvious color block and color difference, and the foundation liquid is distributed more evenly.

[0057] Combining Example 1 with Example 4-5 and Table 1, it can be seen that the thickness of the knitted fabric is 0.3-1 mm and the weight is 80-300 g / m 2 , so that the composite membrane cloth for air cushion has a stable and better application effect, not only is it not easy to leak the foundation liquid during shaking, sideways and inverted, but it can also release the foundation liquid evenly when pressed; combined with Examples 16-17 and Table 1, it can be seen that when the thickness and gram weight of the knitted cloth are lower than the above range, not only will the foundation liquid be easy to leak, but also the uniform release of the foundation liquid will be affected; when the thickness and gram weight of the knitted cloth are higher than the above range, although it will not cause the leakage of the foundation liquid, it will affect the discharge of the foundation liquid. After application testing, obvious color blocks and color differences will appear, indicating that the distribution of the foundation liquid is not uniform.

[0058] In combination with Example 1 and Examples 6-7 and Table 1, it can be seen that when the thickness of the PDMS film is 0.05-0.5 mm, the obtained composite membrane cloth for air cushion has a stable and excellent application effect. Not only is it not easy for the foundation liquid to leak during shaking, sideways and inverted, but it can also release the foundation liquid evenly when pressed; in combination with Examples 18-19 and Table 1, it can be seen that if the thickness of the PDMS film is lower than the above range, the foundation liquid is likely to leak, and it also causes uneven discharge of the foundation liquid. If the thickness of the PDMS film is higher than the above range, when the composite membrane cloth for air cushion is subjected to normal extrusion, the crack structure cannot be fully opened, which will affect the discharge speed and uniformity of the foundation liquid.

[0059] It can be seen from Example 1 and Examples 8-11 and Table 1 that when the elastic yarn count used for the knitted fabric is 30-150D and the elastic yarn is spandex yarn or spandex blended yarn, the obtained composite membrane cloth for air cushion can have stable and excellent application effect.

[0060] It can be seen from Example 1 and Examples 12-13 and Table 1 that in the operation of step S2, the drying temperature is 60-100°C and the drying time is 1-12h, which can make the PDMS membrane-coated material have a better fitting effect with the knitted fabric after molding. At the same time, when a crack structure appears in the subsequent stretching treatment, it can also exert a stable and better application effect.

[0061] Combining Example 1 and Example 14-15 with Table 1, it can be seen that the PDMS film (2) corresponding to the concave parts of the adjacent coils of the knitted fabric is stretched by 100-250% in the transverse direction of the stripes until more than 70% of the knitted fabric has crack structures. The obtained composite membrane cloth for air cushion is not only not easy to leak foundation liquid during the test, but also can release foundation liquid evenly when pressed. Combining Example 20 with Table 1, it can be seen that the limit of the crack structure is more than 70% so that when the composite membrane cloth for air cushion is subjected to normal compression, the crack structure can be opened to quickly and evenly release the foundation. When it is less than 70%, it is found that the foundation liquid is easy to leak and uneven release occurs, which has an adverse effect on the application effect of the composite membrane cloth for air cushion.

[0062] 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 composite film for air cushion, characterized in that: It is formed by laminating a knitted fabric (1) and a PDMS film (2); The knitted fabric (1) is woven from elastic yarn and contains a coil structure and a hole structure inside; The PDMS film (2) is provided with a plurality of evenly or unevenly distributed crack structures (3) at the concave portions of the adjacent coil structures of the knitted fabric (1).

2. The composite film for air cushion according to claim 1, characterized in that: The elastic yarn used in the knitted fabric (1) has a count of 30-150D, and the weaving structure of the knitted fabric (1) is a combination of one or more of rib weave, double rib weave, double reverse weave, tuck weave, furrow weave, half furrow weave, fat flower weave, rib warp plain weave, double rib warp plain weave, double warp plain weave, warp plain weave, warp plain weave, warp diagonal plain weave, warp chain weave, warp diagonal chain weave and spacer weave.

3. The composite film for air cushion according to claim 1, characterized in that: The elastic yarn is spandex yarn or spandex blended yarn, and the spandex blended yarn is blended with spandex and one or more of polyester, nylon, acrylic, modal fiber, acetate fiber, viscose fiber, cupro fiber, and cotton fiber.

4. The composite film for air cushion according to claim 1, characterized in that: The elasticity of the knitted fabric (1) is higher than that of the PDMS film (2), and the elastic recovery rate of the knitted fabric (1) is greater than 90%.

5. The composite film for air cushion according to claim 1, characterized in that: The knitted fabric (1) has a thickness of 0.3-1 mm and a gram weight of 80-300 g / m 2 .

6. The composite film for air cushion according to claim 1, characterized in that: The PDMS membrane (2) is made of the following raw materials in parts by weight: Dow Corning SYLGARD 184 PDMS basic component 8-12 parts; Dow Corning SYLGARD 184 cross-linking curing agent 0.8-1.2 parts.

7. The composite film for air cushion according to claim 1, characterized in that: The thickness of the PDMS film (2) is 0.05-0.5 mm.

8. A method for preparing the composite membrane cloth for air cushion according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1, mixing the raw materials used for preparing the degassed PDMS membrane (2) and coating the mixture on a substrate; S2, placing the knitted fabric (1) on the PDMS membrane (2) coating material for bonding, and after drying, peeling off the bonded knitted fabric (1) and the PDMS membrane (2) as a whole to obtain a semi-finished membrane fabric; S3, stretching the semi-finished membrane cloth obtained after peeling to make a crack structure appear on the PDMS membrane (2), thus obtaining a composite membrane cloth for air cushion.

9. The method for preparing a composite film for an air cushion according to claim 8, characterized in that: In the operation of step S2, the drying temperature is 60-100° C. and the drying time is 1-12 hours.

10. The method for preparing a composite film for an air cushion according to claim 8, characterized in that: In the operation of step S3, the stretching treatment method is: stretching the knitted fabric (1) transversely by 100-250% along the stripe direction, until more than 70% of the PDMS membranes (2) corresponding to the concave parts of the adjacent coil structures of the knitted fabric (1) have uniform or non-uniform crack structures.

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