Double-layer plastic film for silica gel refining and production method of double-layer plastic film

Abstract

The invention discloses a double-layer plastic film for silica gel refining and a production method of the double-layer plastic film, and belongs to the technical field of plastic films. The film is formed by compounding two layers of cascaded master roll materials, and the master roll materials are prepared by taking LLDPE resin, a slipping agent and a nano functional master batch as raw materials through a tape casting method; the production method comprises the steps of mother roll material production and composite molding, the mother roll materials are prepared through raw material mixing, heating melting and tape casting shaping, and then the two rolls of mother roll materials are compounded into a double-layer structure through a self-lapping rewinding machine. Compared with the prior art, the film is excellent in toughness and stretchability, has controllable low viscosity, is not easy to delaminate and damage, and can reliably protect a silica gel sheet; in production, the T-shaped mold can be used for synchronously manufacturing films of multiple specifications and can be used without thick films, so that the cost is reduced, the production efficiency is improved, the pollution of silica gel products is effectively reduced, the qualified rate of finished products is improved, and the method is suitable for various silica gel mixing scenes.

Description

Technical Field

[0001] This invention belongs to the field of plastic film technology, specifically relating to a double-layer plastic film for silicone rubber compounding and its production method. Background Technology

[0002] In the production of silicone products, the rubber mixing and slitting processes are crucial for ensuring product quality. Double-layer plastic film, a core auxiliary material used in silicone rubber mixing, directly impacts production efficiency and finished product yield. In the actual production process, raw rubber is first mixed with vulcanizing agents, color masterbatches, and other materials in a rubber mixing mill to form sheet rolls. Then, double-layer plastic film is simultaneously rolled onto the surface of the silicone sheet, followed by slitting using an automatic slitting machine. Before slitting, the double-layer film is separated and attached to the top and bottom surfaces of the silicone sheet, creating an intermediate isolation to prevent contamination during processing. After slitting, the film is removed, and the silicone strips are fed into a vulcanizing mold for high-temperature vulcanization. Therefore, the double-layer structure and specific properties are core requirements for this type of film.

[0003] In existing technologies, double-layer plastic films for silicone rubber compounding are mainly produced using the blown film method, with LDPE (low-density polyethylene) as the primary raw material. The production process relies on air cooling to achieve film formation, and the double-layer structure is formed by venting air during winding. This technology has been used in the industry for a long time, but as silicone products develop towards diversification and high precision, its inherent defects have gradually become apparent. It is difficult to meet the current production requirements for film performance and efficiency, leading not only to an increase in the scrap rate of silicone products but also to increased production costs, becoming a significant factor restricting silicone manufacturers from improving their competitiveness.

[0004] From a performance perspective, double-layer plastic films produced by blown film production have significant drawbacks: Firstly, the film itself is non-adhesive, and the double-layer structure formed solely by air removal during winding has extremely poor stability, making delamination at the interface prone to occur. This leads to a decrease in the adhesion between the film and the silicone sheet during the slitting process, rendering it ineffective in providing isolation and protection. Secondly, the film lacks sufficient toughness and tensile strength, making it easily torn during the silicone slitting process. The resulting film debris mixes into the silicone material, causing contamination of the silicone sheet and consequently leading to defects in the subsequently vulcanized silicone products. This significantly increases the scrap rate, especially when processing ultra-thick silicone sheets, where a film thickness of 0.08 mm or more is required to barely avoid damage, further increasing material costs.

[0005] Besides performance limitations, blown film production also suffers from limitations in production efficiency and flexibility: its fixed ring mold structure allows for the production of only one width of plastic film per cycle. When companies need to produce multiple specifications of double-layer plastic films for silicone rubber compounding simultaneously, frequent mold and blown film equipment changes are necessary, resulting in cumbersome operation, wasted production time, and low production efficiency. Furthermore, the process characteristics of blown film production dictate lower precision in film thickness control, making it difficult to meet the production requirements of high-precision silicone products. These shortcomings collectively mean that existing double-layer plastic films cannot meet the industry's development needs in terms of production cost, efficiency, and product adaptability, necessitating a new production technology and product structure to overcome these bottlenecks. Summary of the Invention

[0006] The present invention aims to solve the technical problems of the double-layer plastic film for silicone rubber compounding produced by blown film method in the above-mentioned prior art, which are prone to delamination at the interface, insufficient toughness and tensile strength, easy breakage leading to silicone contamination, the need for thick film which increases costs, and the low production efficiency of ring molds and the inability to produce films of multiple specifications simultaneously.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A double-layer plastic film for silicone rubber compounding, the double-layer plastic film is composed of two cascaded master rolls, the master rolls are prepared by casting method, and the raw materials of the master rolls are composed of the following components in parts by weight: 93 parts LLDPE resin, 2 parts slip agent, and 5 parts nano-functional masterbatch.

[0009] Preferably, the double-layer plastic film has a tensile strength ≥25MPa and an elongation ≥300%.

[0010] A method for producing a double-layer plastic film for silicone rubber compounding includes the following steps:

[0011] S1. Master roll production: Master rolls are produced using a casting machine. LLDPE resin, slip agent and nano-functional masterbatch are mixed in proportion and then formed and wound up by the casting machine to obtain the master roll.

[0012] S2. Composite molding: Two rolls of master roll material are combined using a self-developed rewinding machine to form a double-layer film.

[0013] As a preferred option, the specific steps for the production and processing of the master roll material in step S1 are as follows:

[0014] S1.1 Raw material preparation: Prepare LLDPE resin, slip agent and nano-functional masterbatch as raw materials for producing master roll material according to the formula ratio;

[0015] S1.2 Raw material mixing: Pour the above three materials into the automatic mixer in proportion, and set the mixing time to 5-10 minutes;

[0016] S1.3 Heating and Melting: Start the casting machine unit. The automatic feeder sucks the mixed material into the hopper of the casting machine unit. The hopper outlet is connected to the screw inlet. After the raw material resin enters the screw, it passes through the feeding section, melting section, homogenization section for heating and further processing of the connector in sequence, so that the resin is heated and melted.

[0017] S1.4 Casting: The plastic resin, heated and melted by the screw, enters the T-shaped mold. The resin flows through the flow channel in the T-shaped mold cavity to the first cooling roller. After being cooled by the first cooling roller, it is cooled by the second cooling roller, pulled by the traction roller, and trimmed by the online trimming assembly. Finally, the film is guided to the winding air shaft A by the winding roller to be wound up to form a master roll.

[0018] Preferably, the screw on the casting machine is connected to the gearbox, and the gearbox is connected to the motor via a belt; the motor transmits power to the drive shaft of the gearbox via the belt, and the drive shaft is connected to the screw to make the screw rotate.

[0019] Preferably, the temperature of the feeding section is 180-190℃, the temperature of the melting section is 210-220℃, the temperature of the homogenization section is 200-210℃, and the temperature of the connector is 210-220℃.

[0020] As a preferred option, the temperatures of each stage of the T-shaped mold are 220℃, 210℃, 200℃, 200℃, 210℃, and 220℃, respectively.

[0021] Preferably, the film thickness is adjusted by controlling the rotational speed of the first cooling roller and adjusting the screws on the upper die lip of the T-shaped mold.

[0022] As a preferred embodiment, the composite molding process is as follows: The specific steps of the composite molding process in step S2 are as follows:

[0023] Two pre-produced master rolls, A and B, are loaded onto tension shafts A and B of the self-developed rewinding machine, respectively. Master roll A is pulled around inert roller A and two flattening rollers A, while master roll B is pulled around inert roller B and three flattening rollers B before reaching the power winding roller. Finally, master roll A and master roll B are wound onto the winding tube of the winding air shaft B through the winding air shaft, so that the two layers of master rolls are stably and evenly bonded together to form a double-layer film.

[0024] Preferably, the roll tube is coated with adhesive tape for attaching the beginning of the film.

[0025] Compared with the prior art, the technical effects and advantages of the present invention are:

[0026] (1) The present invention achieves a significant improvement in film performance. The double-layer plastic film produced by the specific formula and casting method has stronger toughness and tensile strength, which can meet the usage requirements of the silicone rubber mixing and cutting process, avoid film damage during the cutting process, and the film has controllable low viscosity, which ensures that the two layers are not easy to delaminate after lamination, and can be easily separated when needed. It effectively solves the problems of unstable interface and easy damage of existing films, and provides reliable isolation protection for silicone sheets.

[0027] (2) This invention significantly optimizes production costs, and can meet the usage requirements without relying on thicker films. Compared with existing technologies, it reduces raw material consumption. At the same time, the casting process has a greater advantage in material utilization. It reduces film costs from both the amount of raw materials used and the efficiency of use, saving production costs for silicone manufacturers and improving economic benefits.

[0028] (3) This invention significantly improves production efficiency and flexibility. The T-shaped mold can be adapted to a wider production area. With the multi-component film blade, it can simultaneously produce films of various widths without changing the mold. One mold is compatible with all specifications of film width. It solves the limitation of existing ring molds that can only produce a single specification, reduces production preparation time, improves film production efficiency, and better meets the production needs of enterprises for multi-specification silicone products.

[0029] (4) This invention effectively reduces the risk of contamination of silicone products. By optimizing the film performance and production process, it avoids the debris from film breakage from mixing into the silicone material. At the same time, the stable double-layer structure and reliable isolation effect can reduce the probability of contamination of silicone sheets during the rubber mixing and cutting process, help improve the finished product qualification rate of silicone products, and ensure the stability of product quality. Attached Figure Description

[0030] Figure 1 This is a first-view view of the casting machine unit of the present invention;

[0031] Figure 2 This is a second perspective view of the casting machine unit of the present invention;

[0032] Figure 3 This is a schematic diagram of the structure of the self-developed rewinding machine of this invention;

[0033] Figure 4 This is a flowchart of the production process of the master roll material for this invention;

[0034] Figure 5 This is a flowchart of the double-layer structure thin film composite molding process of the present invention.

[0035] In the diagram: 100, Casting machine unit; 200, Self-developed rewinding machine; 11, Hopper; 12, Screw feed inlet; 13, T-shaped mold; 14, First cooling roller; 15, Second cooling roller; 16, Traction roller; 17, Online edge trimming assembly; 18, Rewinding roller; 19, Rewinding air shaft A; 110, Gearbox; 111, Belt; 112, Automatic cleaning system; 113, Rodless cylinder; 114, Roller cleaning head; 115, Water pipe; 21, Master roll A; 22, Master roll B; 23, Tension shaft A; 25, Tension shaft B; 26, Inertia roller A; 27, Flattening roller A; 28, Inertia roller B; 29, Flattening roller B; 210, Power roll; 211, Rewinding air shaft B; 212, Roll tube. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] The following combination Figures 1 to 5 This application will be described in further detail.

[0038] This application discloses a double-layer plastic film for silicone rubber compounding. The core structure is composed of two cascaded master rolls. The "two cascaded" structure specifically refers to the two master rolls being combined in a stacked manner to form an integral structure. That is, one master roll is located above or below the other master roll, not in a physical nesting or series relationship. Instead, the two layers are tightly bonded together through a subsequent rewinding and lamination process, ultimately forming a film with a stable double-layer structure. The core purpose of this structural design is to allow the two materials to work together to provide isolation and protection for the silicone sheet, adapting to the special usage requirements of the silicone rubber compounding and cutting process.

[0039] The master roll of the double-layer plastic film is prepared by casting. Its raw material components are strictly proportioned by weight, specifically 93 parts LLDPE resin, 2 parts slip agent, and 5 parts nano-functional masterbatch. This formula has been verified by multiple tests, which can not only ensure that the master roll has good processing performance, but also enable the final double-layer film to meet the requirements of toughness, tensile strength and low viscosity in the silicone rubber compounding scenario, laying the foundation for the subsequent film performance to meet the standards.

[0040] To ensure that the double-layer plastic film is not torn during the silicone rubber mixing and cutting process and can effectively protect the silicone sheet, its key performance indicators must meet specific standards. Through actual testing, the tensile strength of the double-layer plastic film is ≥25MPa, the elongation is ≥300%, and it also has the characteristics of low viscosity and adjustable viscosity. This viscosity characteristic can be achieved by adjusting the raw material formula ratio, which not only ensures that the interface delamination does not easily occur after the two layers of master roll are laminated, but also allows the two layers to be easily separated when cutting and using, avoiding the impact of adhesion on the subsequent processing of silicone strips.

[0041] The production method of the double-layer plastic film of this invention mainly consists of two core steps:

[0042] S1. Master roll production: Master roll production requires the use of casting machine 100. After LLDPE resin, slip agent and nano-functional masterbatch are mixed in proportion, the casting machine 100 is used to form and roll the master roll.

[0043] S2. Composite molding: Composite molding requires the use of a self-developed rewinding machine 200 to composite two rolls of produced master rolls to form a double-layer film. The two steps are closely linked to ensure the structural integrity and performance stability of the film.

[0044] In the S1 step of master roll production, the first step is the S1.1 raw material preparation process. Operators must strictly follow the formula ratio and accurately weigh the LLDPE resin, slip agent and nano-functional masterbatch to ensure that the weight ratio of the three raw materials meets the requirement of 93:2:5. At the same time, the purity and appearance of the raw materials must be checked to avoid the mixing of impurities, lumps or deteriorated raw materials, so as to ensure the production quality of master roll from the source.

[0045] After the raw material preparation is completed, proceed to the S1.2 raw material mixing process. Pour the weighed LLDPE resin, slip agent and nano-functional masterbatch into the automatic mixer in proportion. Set the mixing time to 5-10 minutes according to the raw material mixing requirements. After starting the automatic mixer, ensure that the mixer runs stably and that the three materials are fully and evenly mixed to avoid differences in the performance of the subsequent master roll material due to uneven mixing, which would affect the overall quality of the double-layer film.

[0046] After the raw materials are mixed evenly, the S1.3 heating and melting process is started. First, the casting machine 100 is started. The automatic feeding machine equipped with the casting machine 100 sucks the mixed raw materials into the hopper 11 of the casting machine 100. The outlet of the hopper 11 is connected to the screw inlet 12. After the raw material resin enters the screw through the inlet, it will pass through the feeding section, melting section and homogenization section of the screw in sequence for heating. At the same time, it also needs to be further processed by the connector to finally achieve full heating and melting of the resin, preparing it for subsequent casting molding.

[0047] The screw of the casting machine 100 is connected to the gearbox 110, and the gearbox 110 is connected to the motor via the belt 111. In the heating and melting process, the motor transmits power to the drive shaft of the gearbox 110 via the belt 111. The drive shaft is then connected to the screw and drives the screw to rotate. The stable rotation of the screw provides power support for the conveying and heating of raw materials, ensuring that the raw materials can be heated in an orderly and uniform manner in each section of the screw, thus ensuring the melting effect.

[0048] To ensure complete resin melting without overheating or underheating, the temperature of each section of the screw and connector must be strictly controlled. The temperature of the feeding section is set at 180-190℃, the melting section at 210-220℃, the homogenization section at 200-210℃, and the connector at 210-220℃. Operators must monitor temperature changes in real time to ensure that the temperature of each area remains stable within the set range, thus avoiding the impact of temperature fluctuations on the resin melting quality.

[0049] After heating and melting, the process proceeds to step S1.4, the casting molding process. The plastic resin, heated and melted by the screw, enters the T-mold 13. To ensure the flow performance and molding effect of the resin in the mold, the temperature of each stage of the T-mold 13 needs to be set sequentially to 220℃, 210℃, 200℃, 200℃, 200℃, 210℃, and 220℃. After passing through the flow channel in the cavity of the T-mold 13, the resin will be evenly cast to the surface of the first cooling roller 14 for initial cooling.

[0050] After the resin is cast to the first cooling roller 14 for cooling, it will continue to be conveyed to the second cooling roller 15 for secondary cooling to ensure that the resin is completely set. Then, it will be pulled by the traction roller 16 to the online edge trimming assembly 17. The online edge trimming assembly 17 will cut off the irregular parts of the film edge to ensure that the film width is consistent. The cut edge material will be recycled back into the hopper through the recycling system. Finally, the processed film will be guided by the winding roller 18 to the winding air expansion shaft A19 for winding to finally form a master roll. The entire casting process must ensure that the operation of each piece of equipment is coordinated to avoid problems such as film wrinkles and damage.

[0051] In the casting process, the control of film thickness is crucial. This invention achieves precise adjustment of film thickness by controlling the rotation speed of the first cooling roller 14 and adjusting the upper die lip screw of the T-die 13. Operators can adjust the cooling rate and stretching degree of the film by changing the rotation speed of the first cooling roller 14 according to production needs. At the same time, the die lip gap can be changed by turning the die lip screw of the T-die 13, thereby controlling the resin outflow. Ultimately, the film thickness can be adjusted at the micron level, ensuring uniform thickness of the master roll.

[0052] During the production of master roll material, the casting machine 100 is also equipped with an automatic cleaning system 112. This system is located above the first cooling roller 14 and is mainly used to clean the first cooling roller 14 during the entire production process to prevent raw material exudates from adhering to the surface of the cooling roller and affecting the quality of the film produced later. The automatic cleaning system 112 includes a rodless cylinder 113 fixed on the frame of the casting machine 100 and an automatic cleaning head 114 fixed on the moving slide of the rodless cylinder 113. The rodless cylinder has a sealed outer cover connected to a water pipe 115, and the sealed outer cover with water flow inside plays a role in cooling and protecting the rodless cylinder from the high temperature of the die head. In conjunction with the movement of the rodless cylinder 113, the roller cleaning head 114 moves while performing a comprehensive cleaning of the first cooling roller 14.

[0053] After the production of the master roll is completed, the S2 composite molding step is entered. First, the two produced master rolls are marked as master roll A21 and master roll B22 respectively. Then, master roll A21 is loaded onto the tension shaft A23 of the self-developed rewinding machine 200, and master roll B22 is loaded onto the tension shaft B25 of the self-developed rewinding machine 200. During the loading process, it is necessary to ensure that the master rolls are installed firmly and centered to avoid misalignment of the two film layers during subsequent lamination due to installation misalignment.

[0054] After the master roll is installed, the film traction operation is performed. The master roll A21 is tractioned around the inertial roller A26 and two flattening rollers A27, and the master roll B22 is tractioned around the inertial roller B28 and three flattening rollers B29. The inertial rollers are used to generate stable tension in the film and prevent the film from loosening during traction. The flattening rollers have spiral grooves on their surfaces that run from the center to the left and right, which can flatten the film and eliminate wrinkles. Then, the two layers of film reach the power roll 210 together, preparing for subsequent lamination.

[0055] Turn on the frequency converter switch, and the frequency converter controls the motor to rotate. The motor is connected to the power roll 210 through a chain and transmits power. Set the rewinding speed to 10-15 m / min. Under the transmission action of the power roll 210, the two layers of film are smoothly conveyed forward. Finally, the master roll A21 and master roll B22 are taken up by the take-up air shaft and placed on the winding tube 212 of the take-up air shaft B211. Adhesive tape for sticking the beginning of the film is attached to the winding tube 212 to ensure that the beginning of the film is firmly fixed. Under stable rewinding pressure and speed, the two master rolls are smoothly and evenly bonded together to finally form a double-layer structure film product.

[0056] This invention first produces master rolls of material using a specific formula of raw materials through a casting machine 100. After the raw materials are mixed, heated and melted, they are cast by a T-shaped mold 13 to a cooling roller for shaping and winding. Then, the two master rolls are passed through a self-developed rewinding machine 200, and with the help of the tension control of the inert roller and the flattening effect of the flattening roller, they are laminated into a double-layer film under the drive of the power roll 210. During the process, the cleanliness of the equipment is ensured by an automatic cleaning system 112, and the quality of the film is ensured by adjusting the mold and the cooling roller. Finally, a double-layer structure film adapted to silicone rubber is formed.

[0057] Compared with the prior art, the advantages of the present invention are: firstly, it has better performance, with better controllability of film toughness, tensile properties and adhesion, and is not easy to delaminate or break, which can reliably protect silicone sheets and reduce pollution; secondly, it has more efficient and flexible production, with the T-shaped mold 13 capable of producing films of multiple specifications simultaneously without changing the mold, and without the need for thick films to meet the demand, thereby reducing costs and improving the overall quality and efficiency of silicone product production.

[0058] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A double-layer plastic film for use in silicone rubber compounding, characterized in that, The double-layer plastic film is composed of two cascaded master rolls. The master rolls are prepared by casting. The raw materials of the master rolls consist of the following components by weight: 93 parts LLDPE resin, 2 parts slip agent, and 5 parts nano-functional masterbatch.

2. The double-layer plastic film for silicone rubber compounding according to claim 1, characterized in that: The tensile strength of the double-layer plastic film is ≥25MPa, and the elongation is ≥300%.

3. A method for producing a double-layer plastic film for silicone rubber compounding, characterized in that, Includes the following steps: S1. Production of master roll material: Master roll material is produced using a casting machine (100). LLDPE resin, slip agent and nano-functional masterbatch are mixed in proportion and then formed and wound up by the casting machine (100) to obtain master roll material. S2, Composite molding: Two rolls of master roll material are combined using a self-developed rewinding machine (200) to form a double-layer structure film.

4. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 3, characterized in that: The specific steps in the production and processing of the master roll material in step S1 are as follows: S1.1 Raw material preparation: Prepare LLDPE resin, slip agent and nano-functional masterbatch as raw materials for producing master roll material according to the formula ratio; S1.2 Raw material mixing: Pour the above three materials into the automatic mixer in proportion, and set the mixing time to 5-10 minutes; S1.3, Heating and Melting: Start the casting machine (100), and the automatic feeder sucks the mixed material into the hopper (11) of the casting machine (100). The outlet of the hopper (11) is connected to the screw feed inlet (12). After the raw material resin enters the screw, it passes through the feeding section, melting section, homogenization section for heating and the connector for further processing, so that the resin is heated and melted. S1.4, Casting: The plastic resin, after being heated and melted by the screw, enters the T-shaped mold (13). The resin flows through the flow channel in the cavity of the T-shaped mold (13) to the first cooling roller (14). After being cooled by the first cooling roller (14), it is cooled by the second cooling roller (15), pulled by the traction roller (16), and trimmed by the online trimming assembly (17). Finally, the film is guided to the winding air shaft A (19) by the winding roller (18) to be wound up to form the master roll.

5. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 4, characterized in that: The screw on the casting machine (100) is connected to the gearbox (110), and the gearbox (110) is connected to the motor via the belt (111). The motor transmits power to the drive shaft of the gearbox (110) via the belt (111), and the drive shaft is connected to the screw to make the screw rotate.

6. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 4, characterized in that: The temperature of the feeding section is 180-190℃, the temperature of the melting section is 210-220℃, the temperature of the homogenization section is 200-210℃, and the temperature of the connector is 210-220℃.

7. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 4, characterized in that: The temperatures of each stage of the T-shaped mold (13) are 220℃, 210℃, 200℃, 200℃, 200℃, 210℃, and 220℃ respectively.

8. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 4, characterized in that: The film thickness is adjusted by controlling the rotation speed of the first cooling roller (14) and adjusting the upper die lip screw of the T-shaped mold (13).

9. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 3, characterized in that: The composite molding process steps are as follows: The specific steps of the composite molding process in step S2 are as follows: The two pre-made master rolls A (21) and B (22) are loaded onto the tension shafts A (23) and B (25) of the self-developed rewinder (200), respectively. The master roll A (21) is pulled around the inert roller A (26) and two flattening rollers A (27), and the master roll B is pulled around the inert roller B (28) and three flattening rollers B (29) before reaching the power roll roller (210). Finally, the master roll A (21) and master roll B (22) are taken up by the take-up air shaft and placed on the roll tube (212) of the take-up air shaft B (211), so that the two layers of master rolls are stably and evenly combined together to form a double-layer structure film.

10. A method for producing a double-layer plastic film for silicone rubber compounding according to claim 9, characterized in that: The roll tube (212) is covered with adhesive tape for attaching the beginning of the film.

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