A method for compound molding without adhesive

Abstract

The present invention relates to the technical field of material forming, and specifically to a non-adhesive compound forming method, which includes the following specific steps: S1: Mold cleaning; S2: Cutting; S3: Laying of the rubber layer and the adhesive layer, laying the adhesive layer and the rubber layer on the surface of the plastic film in sequence; S4: Inspection of the rubber layer and the adhesive layer; S5: Pre-forming by a press; S6: Pretreatment before curing; S7: Curing and forming; S8: Demolding. By not using traditional adhesives, the present invention reduces the emission of volatile organic compounds, meets the requirements of modern green manufacturing. At the same time, using the adhesive layer to replace the coating of the adhesive improves the bonding performance of the elastic rubber support pad, simplifies the production process, and reduces the labor and time costs.

Description

Technical Field

[0001] The present invention relates to the technical field of material forming, and particularly relates to a binder-free compound forming method. Background Art

[0002] For the bonding of rubber and plastic film, in order to achieve excellent bonding strength, hot adhesives are generally used for bonding. However, such bonding processes are relatively complex, have high requirements for the storage environment and uniformity of the adhesives, and cause relatively large environmental pollution, making them unsuitable for long-term use.

[0003] The "Adapter Forming Process Method" proposed in Publication No.: CN105643947A adopts a structure with a rigid polyurethane foam as the bearing base layer and a sponge stir as the buffer layer. Due to the long storage period, the sponge rubber plate is prone to permanent deformation under long-term pressure, resulting in the failure of the overall adapter layer function and the loss of buffer capacity. At the same time, the sponge rubber plate and polyurethane are commonly bonded with solvent-based rubber adhesives, and the adhesive bonding process is poor, prone to high-temperature bulging on the surface of the adapter layer, affecting the service life of the product.

[0004] The "Adapter and Its Forming Process Method, Transmitting Device" proposed in Publication No.: CN112729007A adopts a structure with a rubber layer as the bearing base layer and a polytetrafluoroethylene film and a surface foam layer as the buffer layer. This forming method has a complex forming process. During the forming process of the foam on the surface of the polytetrafluoroethylene film, wrinkles or white spots are easily formed on the surface of the polytetrafluoroethylene film, seriously affecting the product quality. Moreover, the polytetrafluoroethylene foam layer uses epoxy adhesives, which have poor high-temperature resistance and high environmental pollution, and are not suitable for batch trial production of adapter products.

[0005] The "Rubber Solid Adhesive and Its Preparation Method and Application" proposed in Publication No.: CN103602288A, the rubber solid adhesive is used for bonding untreated polyester filaments and nylon during the production of fire hoses, has high bonding strength, and is superior to other hot melt adhesives in terms of heat resistance and heat resistance, and the bonding is stable. However, this adhesive is not suitable for bonding plastics and rubbers, cannot solve the problem of poor bonding performance, and is also a liquid adhesive, resulting in low production efficiency.

[0006] Therefore, the adhesives used for bonding rubber and plastic film in the prior art have problems such as poor bonding performance, long time consumption during the production process, high production cost, large environmental pollution by volatile organic compounds, and being unsuitable for long-term use. There is an urgent need to propose a compound forming process with lower cost and simpler forming process to solve the problems of poor bonding performance of the product after bonding rubber and plastic film, long time consumption during the production process, high production cost, and large environmental pollution by volatile organic compounds. Summary of the Invention

[0007] In view of this, the present invention aims to propose an adhesive-free compounding molding method to solve the problems of poor bonding performance of rubber and plastic film products, long production time, high production cost, and greater environmental pollution caused by volatile organic compounds.

[0008] The adhesive-free composite molding process of the present invention comprises the following steps: surface treatment of the plastic film; surface treatment of the adhesive layer; surface treatment of the rubber layer; and adhesive-free composite molding between the rubber layer, the adhesive layer and the plastic film. The solution is proposed by the inventor through creative labor and a large number of experiments. The solid adhesive layer is used to replace the existing adhesive. The thickness of the adhesive layer is controlled in the range of 0.58 mm to 0.64 mm, which greatly improves the bonding ability between the rubber layer and the plastic film, breaks the mindset of those skilled in the art, and solves the problem of poor bonding performance of the product after the rubber and the plastic film in the prior art.

[0009] In addition, the present invention has the advantages of low environmental pollution, simple molding process, short processing time, low production cost, light weight, high compression resistance and shock absorption. The elastic rubber support pad has better low heat generation and bending resistance than the polyurethane support pad, which effectively improves the life of the elastic support pad.

[0010] The technical solution of the present invention is achieved in this way:

[0011] The present invention discloses an adhesive-free compounding and molding method, comprising the following specific steps:

[0012] S1: Mould cleaning;

[0013] S2: Cutting: the plastic film is cut to a set size using tool A, and the rubber layer and glue layer are cut to a set size using tool B, wherein the thickness of the glue layer ranges from 0.58 to 0.64 mm;

[0014] S3: Laying the rubber layer and the glue layer, laying the glue layer and the rubber layer in sequence on the surface of the plastic film, and the distance between the rubber layer and the glue layer and the edge of the plastic film is 2-8 mm;

[0015] S4: inspecting the rubber layer and the glue layer, and cutting open the bulges or bubbles on the surface of the rubber layer and the glue layer to remove impurities;

[0016] S5: Preforming by press, after the adhesive layer is laid, it is placed in the press for more than 20 minutes and then taken out;

[0017] S6: before curing begins, the plastic film attached to the rubber layer and the glue layer is placed in the middle of the mold, and the distance between the plastic film and the edge of the mold cavity is 2-6 mm;

[0018] S7: After the mold is installed, close the mold slowly. After preheating for 1 - 6 minutes, perform mold closing and pressure holding. During this period, observe whether there are any abnormalities in the mold, and then adjust the curing temperature of the oven to 100 - 200 °C and the curing time to 30 - 50 minutes.

[0019] S8: Demold. After curing is completed, take out the product from the mold completely to obtain a high-quality elastomeric support pad material.

[0020] Further, in step S2, the plastic film is one of a polyester film, a polyethylene film, a polypropylene film, and a polytetrafluoroethylene film, and the plastic film is drawn by a pultrusion or curling method.

[0021] Further, the plastic film is cut to a set size using tooling A. The surface of the plastic film needs to be treated with sodium naphthalene and has a thickness between 0.4 mm and 0.6 mm.

[0022] Further, the adhesive layer is one of chloroprene rubber or bromobutyl rubber. The adhesive layer is processed using a precision calender, and no bubbles, wrinkles, or other defects are allowed on the surface. After being made, it is cut to a set size using tooling B and then wound up for storage.

[0023] Further, the preparation steps of the adhesive layer are as follows:

[0024] ST1: The rubber type of the adhesive layer uses chloroprene rubber. The fillers used include carbon black, silica, tackifier, accelerator CZ, and sulfur. The ratio is 50 - 100 parts of chloroprene rubber, 20 - 60 parts of carbon black, 10 - 30 parts of silica, 0 - 30 parts of tackifier, 0 - 5 parts of accelerator CZ, and 0 - 5 parts of sulfur.

[0025] ST2: Use a mixer and an open mill for mixing and forming. The rotation speed is 35 / min, the mixing temperature is 70 °C, and the discharge temperature does not exceed 120 °C.

[0026] ST3: After mixing and forming, feed the mixed rubber into a four-roll calender for calendering and forming. The speed ratios of the AB and BC rollers are controlled at 0.9, the speed ratio of the CD rollers is controlled at 1, the roller gap of the AB rollers is controlled at 0.7 mm, the roller gap of the BC rollers is controlled at 0.55 mm, the roller gap of the CD rollers is controlled at 0.8 mm, and the total thickness of the film is controlled between 0.58 and 0.64 mm and then curled and formed.

[0027] ST4: Cut the film produced in step ST3 to a set size using tooling B to obtain the adhesive layer.

[0028] Further, in step S2, the rubber layer is one or more of natural rubber, styrene-butadiene rubber, ethylene propylene diene monomer rubber, and nitrile rubber, and is refined by an open mill, with the thickness controlled at 3.8 - 4.2 mm. Bubbles, wrinkles, and other defects are not allowed on the surface, and it is cut to the set size using tooling B.

[0029] Further, in step S2, the length and width dimensions of tooling A are 300 mm × 200 mm, and the length and width dimensions of tooling B are 290 mm × 190 mm.

[0030] Further, in step S5, the press is a flat vulcanizing machine, and the specification model is one of 200t, 300t, or 400t.

[0031] Further, in step S7, the oven is 2.3 m high and 1.5 m wide, and the oven temperature range is 0 - 200 °C.

[0032] Further, it also includes step S9. Cut the elastomeric support pad material in S8 into three specimens each with a length of 200 mm, a width of 25 mm, and a thickness of 5 mm, and place them in a universal tensile machine to test the 180° peel strength of the samples.

[0033] The preparation steps of the conventional elastomeric support pad are as follows: S1: Mold cleaning; S2: Cut the plastic film into an appropriate size according to tooling A, and cut the rubber layer into an appropriate size using tooling B; S3: Use a 1.5 - inch brush to dip a small amount of cleaning agent and clean the surface of the sodium naphthalene layer of the plastic film to ensure that there are no other impurities on the surface of the plastic film; S4: Use a 1.5 - inch brush to dip a small amount of Chemlok and brush one side of the sodium naphthalene - treated layer of the plastic film to ensure that the adhesive is evenly coated; S5: Rubber layer laying; S6: Press pre - forming; S7: Curing and forming; S8: Demolding.

[0034] Using Chemlok to bond the plastic film and the rubber layer is a commonly used method in the art, and its bonding performance exceeds the adhesion between the rubber and the plastic film. Therefore, in conventional selection, rubber will not be used to replace Chemlok to bond the plastic film to improve the bonding performance.

[0035] Meanwhile, the process of brushing Chemlok takes a long time and has high requirements. Taking a 500×500 mm support pad as an example, the required adhesive thickness range is between ±0.02 mm. Whether it is manual or machine operation, it is time - consuming and difficult to meet the requirements. In this process, about 0.1 kg of Chemlok is needed. The domestic Chemlok is 80 yuan / kg, the imported Chemlok is 160 yuan / kg, and the most expensive Chemlok reaches 320 yuan / kg. However, the cost of the adhesive layer used in the present invention is only 15 yuan / kg, which is much lower than the cost of Chemlok. Moreover, using the finished adhesive layer for forming significantly shortens the production time and avoids the occurrence of uneven coating and other situations that may occur during the application of the adhesive, which helps to improve the product quality.

[0036] Compared with the prior art, a non - adhesive compounding and forming method of the present invention has the following advantages:

[0037] Through this forming method, the present invention does not use traditional adhesives, reducing the emission of volatile organic compounds, meeting the requirements of modern green manufacturing, having low environmental pollution, saving the cost of purchasing and applying adhesives. At the same time, using an adhesive layer to bond the plastic film and the rubber layer improves the bonding performance of the elastic rubber support pad.

[0038] By using an adhesive layer to replace the adhesive coating, the present invention simplifies the production process, reduces the labor and time costs. Since no additional adhesive coating and drying time are required, the entire production cycle is shortened, improving the overall efficiency of the production line.

[0039] In addition to the advantages of being lightweight, high - compressive and shock - absorbing, the elastic rubber support pad of the present invention also has better low heat generation and anti - bending properties compared with polyurethane support pads, which can effectively extend the life of the elastic support pad. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The accompanying drawings, which form a part of the present invention, are used to provide a further understanding of the present invention. The schematic embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation to the present invention. In the drawings:

[0041] Figure 1 is a schematic structural diagram of the elastomeric support pad of the present invention.

[0042] Description of the reference numerals:

[0043] 1, plastic film; 2, adhesive layer; 3, rubber layer. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0044] In order to make the technical means, objectives and effects of the present invention easy to understand, the embodiments of the present invention will be described in detail below with reference to specific drawings.

[0045] It should be noted that all the terms indicating directions and positions in the present invention, such as: "upper", "lower", "left", "right", "front", "rear", "vertical", "horizontal", "inner", "outer", "top", "bottom", "lateral", "longitudinal", "center", etc., are only used to explain the relative positional relationship and connection situation between components in a certain specific state, and are only for the convenience of describing the present invention, rather than requiring the present invention to be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation to the present invention. In addition, the descriptions involving "first", "second", etc. in the present invention are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features.

[0046] In the description of the present invention, unless otherwise clearly defined and limited, the terms "installed", "connected", and "coupled" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or an integral connection; it may be a mechanical connection; it may be directly connected, or indirectly connected through an intermediate medium, and it may be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0047] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0048] Compounding and Molding refers to the process of mixing and compounding multiple raw materials and processing them into a specific shape. This process is widely used in industries such as rubber, plastics, and composite materials, aiming to manufacture products with specific properties and uses.

[0049] Through actual tests, it is known that the tensile shear strength of the bonding between natural rubber and PTFE film using a high-performance adhesive such as Chemlok is usually between 1 - 3 MPa. For flexible materials, the peel strength may vary within the range of 0.5 - 2 N / mm.

[0050] The specific steps for preparing a conventional elastomeric support pad are as follows: S1: Mold cleaning. Clean the mold with a mold cleaner. After cleaning the mold surface, apply a release agent to the mold surface with a clean gauze. S2: Cutting. Cut the plastic film into an appropriate size according to Tooling A, and cut the rubber layer into an appropriate size according to Tooling B. S3: Cleaning. Use a 1.5-inch brush to dip a small amount of cleaning agent and clean the surface of the sodium naphthalene layer of the plastic film to ensure that there are no other impurities on the plastic film surface. After standing for 5 minutes, set aside. S4: Glue brushing. Use a 1.5-inch brush to dip a small amount of Chemlok and brush one side of the sodium naphthalene-treated layer of the plastic film to ensure that the adhesive is evenly applied and there is no missed brushing. S5: Rubber layer laying. Lay the rubber layer on the plastic film surface, and the distance between the rubber layer and the four ends of the plastic film is 5 mm. S6: Pre-forming by press. After the glue layer is laid, place it in the press and press for more than 20 minutes before taking it out. S7: Before curing starts, place the plastic film with the attached rubber layer in the middle of the mold, and the distance between the plastic film and the four ends of the mold cavity is 2 - 4 mm. S8: After the mold is assembled, slowly close the mold. After preheating for 2 - 3 minutes, close the mold and hold the pressure. Observe whether there are any abnormalities in the mold during this period, and then adjust the curing temperature to 150 °C and the curing pressure to 40 minutes. S9: Demolding. After curing is completed, take out the product completely from the mold to obtain a high-quality elastomeric support pad material.

[0051] The present invention discloses a method for compound molding without an adhesive, including the following specific steps:

[0052] S1: Mold cleaning;

[0053] S2: Cutting. Cut the plastic film 1 into a set size according to Tooling A, and cut the rubber layer 3 and the glue layer 2 into a set size according to Tooling B;

[0054] S3: Laying the rubber layer 3 and the glue layer 2. Lay the glue layer 2 and the rubber layer 3 on the plastic film 1 surface in sequence, and the distance between the rubber layer 3 and the glue layer 2 and the edge of the plastic film 1 is 2 - 8 mm;

[0055] S4: Inspecting the rubber layer 3 and the glue layer 2, and cutting open the bulges or bubbles on the surfaces of the rubber layer 3 and the glue layer 2 to remove impurities;

[0056] S5: Pre-forming by press. After the glue layer 2 is laid, place it in the press and press for more than 20 minutes before taking it out;

[0057] S6: Before curing starts, place the plastic film 1 with the attached rubber layer 3 and glue layer 2 in the middle of the mold, and the plastic film 1 is 2 - 6 mm away from the edge of the mold cavity;

[0058] S7: After the mold is assembled, slowly close the mold. After preheating for 1 - 6 minutes, close the mold and hold the pressure. Observe whether there are any abnormalities in the mold during this period, and then adjust the curing temperature to 100 - 200 °C and the curing time to 30 - 50 minutes;

[0059] S8: Demoulding. After curing is completed, the product can be taken out of the mold completely to obtain a high-quality elastomeric support pad material.

[0060] By precisely controlling the laying and pressing processes of each layer of materials, the tight bonding between the plastic film 1, the adhesive layer 2, and the rubber layer 3 is ensured, thereby improving the bonding strength of the overall structure. Then, after the rubber layer 3 and the adhesive layer 2 are laid, inspections are carried out, and a utility knife is used to deal with bulges or bubbles and remove surface impurities to ensure that there are no defects inside the finished product, improving the reliability and durability of the product. Subsequently, during the pre-forming and curing processes using a press, the temperature, time, and pressure parameters are strictly controlled to ensure the dimensional accuracy and surface finish of the elastomeric support pad material.

[0061] This setting does not use traditional adhesives, reducing the emissions of volatile organic compounds (VOCs), meeting the requirements of modern green manufacturing, eliminating the costs of purchasing and applying adhesives, simplifying the production process, reducing labor and time costs, and shortening the entire production cycle as no additional adhesive coating and drying time are required, improving the overall efficiency of the production line.

[0062] Specifically, in step S1, the mold material can be metal, backing cloth, or other fiber-reinforced composite materials.

[0063] Metal molds have good heat conduction performance, can quickly and evenly transfer heat, ensure uniform temperature distribution during the curing process, are strong and durable, can withstand the pressing and curing processes under high pressure and high temperature conditions, are suitable for mass production, and can achieve very high dimensional accuracy through precision machining, ensuring the consistency and high quality of the finished product.

[0064] The cost of backing cloth molds is usually lower than that of metal molds, especially more economical for small-batch or trial-produced products, and can be quickly customized into molds of different shapes and sizes according to specific requirements, shortening the development cycle.

[0065] Fiber-reinforced composite materials combine the advantages of high strength and low density, making the mold both strong and lightweight. By selecting appropriate matrix resins and reinforcing fibers, excellent mechanical properties such as tensile strength and flexural modulus can be obtained to meet specific application requirements.

[0066] This setting can significantly improve the effect of the compound molding process by reasonably selecting the mold material and combining appropriate cleaning and mold release agent treatment, ensuring the high quality and efficient production of the final product.

[0067] Specifically, in step S2, the plastic film 1 is a friction-reducing material for the elastomeric support pad. The plastic film 1 can be polyester film, polyethylene film, polypropylene film, polytetrafluoroethylene film, etc., and the plastic film 1 is drawn by methods such as pultrusion and coiling.

[0068] The polyester film has good tensile strength and wear resistance, and is suitable for applications that need to withstand large mechanical stresses. It can maintain stable dimensions even in an environment with large temperature changes and is not easily deformed.

[0069] The polyethylene film has good flexibility and ductility, can well adapt to complex shapes and bending requirements, has natural waterproof performance, and is suitable for humid or underwater environments.

[0070] The polypropylene film combines relatively high strength and rigidity, is suitable for applications that require a certain amount of structural support, has excellent electrical insulation performance, and is applicable to electronic devices and electrical products.

[0071] The PTFE film is famous for its extremely low friction coefficient, is very suitable as an antifriction material to reduce wear between moving parts, can be used for a long time at very high temperatures, and is applicable to applications in extreme environments.

[0072] This setting can optimize the production process while ensuring product performance and meet the requirements of different application scenarios by reasonably selecting the material of plastic film 1 and combining appropriate processing methods such as pultrusion and curling.

[0073] Specifically, plastic film 1 is cut to a suitable size according to fixture A. Its surface needs to be treated with sodium naphthalene, and the thickness is between 0.4 mm and 0.6 mm.

[0074] Precisely cut plastic film 1 according to fixture A to ensure perfect fit with the subsequent rubber layer 3 and adhesive layer 2, avoiding poor bonding or material waste caused by size mismatch. The standardized cutting size simplifies the production process, reduces the time for manual adjustment, and improves the overall production efficiency. The sodium naphthalene treatment is a chemical treatment method. By dissolving metallic sodium in naphthalene solution and then applying it to the plastic surface, the polarity and surface energy of the plastic surface can be significantly improved. After the sodium naphthalene treatment, the surface of plastic film 1 is more likely to form a firm bond with other materials such as rubber layer 3, enhancing the interfacial bonding force. The appropriate thickness range provides sufficient mechanical strength and flexibility, being neither easily broken nor too soft to affect the forming effect. Within this thickness range, plastic film 1 can effectively transfer heat during the curing process and evenly distribute internal stresses, preventing local overheating or stress concentration. 0.4 mm to 0.6 mm is a relatively ideal thickness range, which can not only meet the performance requirements of most applications but also not increase too much cost. Plastic film 1 within this thickness range has good processability, facilitating stretching operations such as pultrusion and curling, and will not cause processing difficulties due to being too thin. The moderate thickness helps to maintain shape stability and reduce the possibility of deformation during high-temperature curing.

[0075] Preferably, the surface tension value of the surface of the plastic film 1 after being treated with a sodium naphthalene layer is above 50.

[0076] Specifically, in step S2, the adhesive layer 2 is a tackifying material for the elastic support pad, and the adhesive layer 2 can be chloroprene rubber, bromobutyl rubber, etc.

[0077] Chloroprene rubber has a wide range of adhesion capabilities, can form strong adhesions with various materials including metals, plastics, and woods, has good resistance to ultraviolet rays, ozone, and other environmental factors, and is suitable for outdoor use.

[0078] Bromobutyl rubber forms high-strength adhesions with various substrates such as metals, glass, plastics, etc., is especially suitable for applications requiring high sealing performance, is known for its extremely low gas permeability, is particularly suitable for application scenarios requiring sealing performance, has excellent thermal stability and antioxidant properties, and can still maintain good physical properties after long-term use.

[0079] By selecting an appropriate rubber material, a firm adhesion between the plastic film 1 and the rubber layer 3 is ensured, and the stability of the entire structure is improved.

[0080] Specifically, the adhesive layer 2 is processed by a precision calender, with the thickness controlled between 0.58 mm and 0.64 mm. Bubbles, wrinkles, and other defects are not allowed on the surface. The B tooling is used to cut it to an appropriate size, and then it is wound up and stored.

[0081] The precision calender can accurately control the thickness of the adhesive layer 2 between 0.58 mm and 0.64 mm, ensuring that the thickness of each piece of the adhesive layer 2 is consistent, avoiding differences in adhesion strength caused by uneven thickness. Through precision calendering, air bubbles, wrinkles, and other surface defects can be effectively eliminated, providing a smooth and flat surface, which is very important for subsequent bonding operations. The thickness of the adhesive layer 2 is controlled between 0.58 mm and 0.64 mm. If the thickness is too thick, the entire bonding is equivalent to the bonding between the adhesive layer 2 and the plastic, and the product forming quality is poor, and the adhesive layer 2 is prone to blistering and uneven thickness. If the thickness is too thin, it is equivalent to the direct bonding of the rubber to the plastic during the bonding process, and the bonding strength of the product after bonding is insufficient, making it difficult to meet the quality requirements of the product. A smooth and defect-free surface can better contact the plastic film 1 or other materials to form a firm bonding interface, avoiding bonding failure caused by surface defects. A surface without air bubbles and wrinkles makes the final product look neat and beautiful, enhancing the market competitiveness of the product. The adhesive layer 2 is accurately cut according to the B tooling to ensure its perfect fit with the plastic film 1 and the rubber layer 3, avoiding poor bonding or material waste caused by size mismatch. The standardized cutting size simplifies the production process, reduces the time for manual adjustment, and improves the overall production efficiency. Winding up and storing can effectively protect the adhesive layer 2, preventing it from being damaged or contaminated during storage and transportation. The wound-up adhesive layer 2 is convenient for management and handling, saves storage space, and improves logistics efficiency.

[0082] This setting ensures the uniformity and surface quality of the adhesive layer 2 through a precision calender and strict thickness control, enhances the bonding effect with the plastic film 1 and the rubber layer 3, and the standardized cutting size and winding storage simplify the production process, improving the production efficiency and the consistency of product quality.

[0083] Preferably, the preparation steps of the adhesive layer 2 are as follows:

[0084] ST1: The rubber type of the adhesive layer 2 is chloroprene rubber, and the fillers used include carbon black, silica, tackifier, accelerator CZ, and sulfur. The ratio is 50 - 100 parts of chloroprene rubber, 20 - 60 parts of carbon black, 10 - 30 parts of silica, 0 - 30 parts of tackifier, 0 - 5 parts of accelerator CZ, and 0 - 5 parts of sulfur;

[0085] ST2: Use an internal mixer and an open mill for mixing and forming, with a rotation speed of 35 / min, a mixing temperature of 70°C, and the discharge temperature not exceeding 120°C;

[0086] ST3: After mixing and forming, feed the mixed rubber into a four - roll calender for calendering and forming. The speed ratios of the AB and BC rollers are controlled at 0.9, the speed ratio of the CD rollers is controlled at 1, the roller gap of the AB rollers is controlled at 0.7 mm, the roller gap of the BC rollers is controlled at 0.55 mm, the roller gap of the CD rollers is controlled at 0.8 mm, and the total thickness of the film is controlled between 0.58 - 0.64 mm and then coiled and formed;

[0087] ST4: Cut the film produced in step ST3 into a set size using fixture B to obtain the adhesive layer 2.

[0088] Through precise proportioning, it is ensured that the adhesive layer 2 has good mechanical properties, bonding effect, and weather resistance, ensuring that various components are fully mixed to form a uniform composite material. By adjusting the roller gaps and speed ratios, it is ensured that the total thickness of the film is between 0.58 mm and 0.64 mm, providing stable mechanical properties, ensuring better exertion of the bonding performance of the adhesive layer 2, and improving the bonding force between the rubber layer 3 and the plastic film 1. At the same time, the standardized size and precise position laying ensure the tight fit between layers.

[0089] The selection of different additives in this setting can adjust the performance of the adhesive layer 2 according to specific requirements. By strictly controlling the mixing conditions, the finished products of each production can maintain a high degree of consistency, ensuring the stable quality of each batch of the adhesive layer 2. The standardized size simplifies the production process, improves the production efficiency and the consistency of product quality. Precise cutting reduces the generation of excess materials and lowers the cost.

[0090] Specifically, in step S2, the rubber layer 3 is a reinforcing material for the elastic support pad, and the rubber layer 3 is made by refining natural rubber, styrene - butadiene rubber, ethylene - propylene - diene monomer rubber, nitrile rubber, etc. through mixing, open - milling, etc.

[0091] By selecting appropriate rubber materials, the elastic support pad is provided with the necessary structural strength and elasticity, and the overall stability and durability are enhanced. The high elasticity and softness of the rubber material provide the product with good shock absorption and cushioning effects, improving the user experience. Different types of rubber materials can provide specific functions according to specific application requirements, such as weather resistance, chemical resistance, oil resistance, etc., extending the service life of the product.

[0092] This setting can optimize the production process while ensuring high product performance and meet the needs of different application scenarios by rationally selecting rubber materials and combining appropriate mixing or open mixing treatments.

[0093] Specifically, the rubber layer 3 is refined by an open mill, the thickness is controlled to be 3.8-4.2 mm, bubbles, wrinkles and other defects are not allowed on the surface, and the rubber layer 3 is cut into appropriate sizes by using a B tool.

[0094] Use a high-precision mixing mill to refine and control the thickness of the rubber layer 3, accurately adjust the roller spacing to ensure that the thickness of the rubber layer 3 is strictly controlled between 3.8mm and 4.2mm, maintain an appropriate roller temperature of usually 50℃ to 70℃ to ensure that the rubber material has good fluidity and uniformity, adjust the roller speed according to the material properties, and ensure that there are no bubbles, wrinkles or other defects on the surface of the rubber layer 3.

[0095] This arrangement ensures the uniformity and bonding effect of the rubber layer 3 through an open mill and strict thickness and surface quality control. The standardized cutting size simplifies the production process and improves production efficiency and consistency of product quality.

[0096] Specifically, in step S2, the length and width dimensions of tooling A are 300 mm×200 mm, and the length and width dimensions of tooling B are 290 mm×190 mm.

[0097] The length and width of tool B are 10mm smaller than those of tool A. Tool A is used to cut plastic film 1, and tool B is used to cut rubber layer 3 and adhesive layer 2. Ensure that rubber layer 3 and adhesive layer 2 are slightly smaller than plastic film 1 so that an appropriate edge distance of 5mm can be left during assembly to prevent edge overflow from affecting the appearance and avoid poor bonding or material waste due to size mismatch.

[0098] The setting of tooling of different sizes ensures the precise fit between the layers of materials, avoiding poor bonding or material waste caused by size mismatch. The appropriate small size difference ensures that there is enough space between the layers for bonding, and the edges are neat and beautiful. The standardized size simplifies the production process, reduces the time of manual adjustment, and improves the overall production efficiency.

[0099] Specifically, in step S3, the distances between the rubber layer 3 and the adhesive layer 2 from the four ends of the plastic film 1 are 5 mm.

[0100] The 5-mm edge distance can effectively prevent the adhesive layer 2 from overflowing to the edge of the plastic film 1 during the pressing process, keeping the product appearance neat. Even if there is a small amount of glue overflow, the 5-mm reserved space makes the subsequent cleaning work easier, reducing the time and difficulty of trimming. The appropriate edge distance ensures the tight fitting between the layers of materials, avoiding poor bonding or bubble formation caused by excessive tightness at the edges. Sufficient edge space helps to enhance the quality of the bonding interface and provide a stronger bonding force. The 5-mm edge distance provides a clear reference line for the operator, facilitating the accurate laying of the rubber layer 3 and the adhesive layer 2, reducing the possibility of human error, simplifying the production process, improving the production efficiency and the consistency of product quality, enhancing the overall appearance quality of the product, and increasing the market competitiveness.

[0101] Specifically, in step S5, the press is a flat vulcanizing machine, and the specifications and models can be 200t, 300t, and 400t.

[0102] The flat vulcanizing machine can provide a uniform pressure distribution throughout the pressing process, ensuring the tight fitting and firm bonding between the layers of materials. By applying an appropriate pressing force, the air between the layers can be effectively removed, reducing the formation of bubbles and wrinkles and improving the surface quality.

[0103] The flat vulcanizing machine is usually equipped with an advanced temperature control system, which can maintain a stable temperature during the curing process to ensure the full vulcanization of rubber and other materials. The precise time control makes the curing process more controllable, ensuring the consistent curing effect of each batch of products. Modern flat vulcanizing machines mostly adopt an automated control system, reducing manual intervention and improving production efficiency.

[0104] This setting can optimize the production process while ensuring the high performance of the product by reasonably selecting and using a 200t, 300t, or 400t flat vulcanizing machine to meet the requirements of different application scenarios.

[0105] Specifically, in step S6, it is required that the distance between the plastic film 1 and the four ends of the mold cavity is 2 - 4 mm.

[0106] The 2 - 4-mm edge distance can effectively prevent the plastic film 1 from exceeding the mold cavity range during the pressing process, avoiding the flash phenomenon and keeping the product appearance neat. The appropriate edge distance ensures the tight fitting between the plastic film 1 and the mold cavity, avoiding poor bonding or bubble formation caused by excessive tightness at the edges, helping to enhance the quality of the bonding interface and providing a stronger bonding force.

[0107] Specifically, in step S7, after preheating for 2 - 3 minutes, close the mold and apply pressure to hold it. During this period, observe whether there are any abnormalities in the mold, and then adjust the curing temperature of the equipment to 150°C and the curing pressure to 40 minutes.

[0108] The 2 - 3 - minute preheating ensures uniform heating of the mold and materials, reduces stress and thermal shock caused by temperature differences, and improves the bonding effect. Closing the mold and applying pressure to hold it ensures tight fitting of each layer of materials, monitors the mold status in real - time, discovers and handles abnormal situations in a timely manner, and guarantees production safety and quality. The curing temperature of 150°C not only ensures sufficient vulcanization or cross - linking of the materials but also prevents material degradation due to excessive temperature, providing an efficient curing effect. The 40 - minute curing time ensures uniform heating of the entire product, enhances the mechanical properties and durability of the product, and reduces the possibility of rework.

[0109] Specifically, in step S7, the oven is 2.3 m high and 1.5 m wide, and the oven temperature range is 0 - 200°C.

[0110] The larger size can accommodate products with larger or more complex shapes, is suitable for batch production and processing of large products. The sufficiently large space facilitates the operation personnel to enter and place the mold, improving operation convenience and safety. The temperature range from room temperature to 200°C can meet the requirements of different materials and processes, is applicable to various curing and heat treatment processes. The oven is usually equipped with an advanced temperature control system, which can achieve precise control throughout the temperature range to ensure the consistency of each batch of products.

[0111] Example 1

[0112] Preparation of plastic film 1: Cut plastic film 1 to the same size as tooling A and place it at the lower end of the mold. Plastic film 1 is 1200 mm wide, and 3 - mm - wide grooves are designed at both the front and rear ends to prevent slipping during the laying process of plastic film 1.

[0113] Preparation of adhesive layer 2: Adhesive layer 2 is mixed and kneaded and formed according to the ratio of 100 parts of chloroprene rubber, 30 parts of carbon black, 15 parts of white carbon black, 5 parts of tackifier, 1.5 parts of accelerator CZ, and 1 part of sulfur. After that, using a precision calender, the thickness is controlled between 0.58 mm and 0.64 mm, pressed into a roll, and cut into the same size with tooling B, and then laid flat in the middle of plastic film 1.

[0114] Preparation of rubber layer 3: The rubber type of the rubber can be natural rubber or nitrile rubber. Through the methods of internal mixing and open mixing, fillers are added for mixing and forming. The thickness is controlled between 3.8 mm and 4.2 mm, and it is cut into the same size with tooling B and laid on top of adhesive layer 2, requiring complete overlap of adhesive layer 2 and rubber layer 3.

[0115] Pre - pressing forming: After laying the rubber layer 3, place it in a 200t press at a temperature of 23 ± 5°C, close the mold and pre - press for 20 minutes.

[0116] Curing and bonding: After pre - pressing for 20 minutes, raise the temperature for curing. The required curing temperature is 150°C, the curing time is 40 minutes, and the curing pressure is 12 MPa.

[0117] Example 2

[0118] Preparation of plastic film 1: Cut the plastic film 1 to the same size as the A tooling and place it at the lower end of the mold. The plastic film 1 is 1200 mm wide, and 3 - mm - wide grooves are designed at both the front and rear ends to prevent slipping during the laying process of the plastic film 1.

[0119] Preparation of adhesive layer 2: After mixing and kneading the adhesive layer 2 according to the ratio of 100 parts of chloroprene rubber, 30 parts of carbon black, 15 parts of silica, 10 parts of tackifier, 1.5 parts of accelerator CZ, and 1 part of sulfur, use a precision calender to control the thickness between 0.58 mm and 0.64 mm, press it into a roll, cut it to the same size with the B tooling, and lay it flat in the middle of the plastic film 1.

[0120] Preparation of rubber layer 3: Use an open mill to control the thickness between 3.8 - 4.2 mm, and no bubbles, wrinkles or other defects are allowed on the surface. Cut it to the same size with the B tooling and lay it on top of the adhesive layer 2. The rubber type can be natural rubber or nitrile rubber, and through the methods of internal mixing and open mixing, add fillers for mixing and forming, control the thickness between 3.8 mm and 4.2 mm, cut it to the same size with the B tooling, and lay it on top of the adhesive layer 2, requiring the complete overlap of the adhesive layer 2 and the rubber layer 3.

[0121] Pre - pressing forming: After laying the rubber layer 3, place it in a 200t press at a temperature of 23 ± 5°C, close the mold and pre - press for 20 minutes.

[0122] Curing and bonding: After pre - pressing for 20 minutes, raise the temperature for curing. The required curing temperature is 150°C, the curing time is 40 minutes, and the curing pressure is 12 MPa.

[0123] Example 3

[0124] Preparation of plastic film 1: Cut the plastic film 1 to the same size as the A tooling and place it at the lower end of the mold. The plastic film 1 is 1200 mm wide, and 3 - mm - wide grooves are designed at both the front and rear ends to prevent slipping during the laying process of the plastic film 1.

[0125] Preparation of Adhesive Layer 2: After mixing and molding the adhesive layer 2 according to the ratio of 100 parts of chloroprene rubber, 30 parts of carbon black, 15 parts of silica, 15 parts of tackifier, 1.5 parts of accelerator CZ, and 1 part of sulfur, it is pressed into a roll using a precision calender with the thickness controlled between 0.58 mm and 0.64 mm. Then it is cut into the same size using Tooling B and laid flat in the middle of plastic film 1.

[0126] Preparation of Rubber Layer 3: Using an open mill, the thickness is controlled between 3.8 - 4.2 mm, and there should be no bubbles, wrinkles, or other defects on the surface. Then it is cut into the same size using Tooling B and laid on top of the adhesive layer 2. The rubber type can be natural rubber or nitrile rubber, and through the methods of internal mixing and open mixing, fillers are added for mixing and molding. The thickness of the rubber layer 3 is controlled between 3.8 mm and 4.2 mm, and it is cut into the same size using Tooling B and laid on top of the adhesive layer 2, requiring the complete overlap of the adhesive layer 2 and the rubber layer 3.

[0127] Pre - pressing and Forming: After laying the rubber layer 3, it is placed in a 200t press at a temperature of 23 ± 5 °C for mold closing and pre - pressing for 20 minutes.

[0128] Curing and Bonding: After pre - pressing for 20 minutes, it is heated for curing. The required curing temperature is 150 °C, the curing time is 40 minutes, and the curing pressure is 12 MPa.

[0129] Comparative Example 1

[0130] Mold Cleaning: Clean the mold using a mold cleaner. After cleaning the mold surface, apply a release agent to the mold surface with a clean gauze.

[0131] Preparation of Plastic Film 1: Cut the plastic film 1 into an appropriate size using Tooling A, and cut the rubber layer 3 into an appropriate size using Tooling B. Use a 1.5 - inch brush to dip a small amount of cleaning agent and clean the naphthalene - sodium layer surface of the plastic film 1 to ensure there are no other impurities on the surface of the plastic film 1. After standing for 5 minutes, it is set aside. Then use a 1.5 - inch brush to dip a small amount of Chemlok and brush one side of the naphthalene - sodium treated layer of the plastic film 1 to ensure uniform brushing of the adhesive and no missed brushing.

[0132] Preparation of Rubber Layer 3: Using an open mill, the thickness is controlled between 3.8 - 4.2 mm, and there should be no bubbles, wrinkles, or other defects on the surface. Then it is cut into the same size using Tooling B and laid on top of the adhesive layer 2. The rubber type can be natural rubber or nitrile rubber, and through the methods of internal mixing and open mixing, fillers are added for mixing and molding. The thickness of the rubber layer 3 is controlled between 3.8 mm and 4.2 mm, and it is cut into the same size using Tooling B and laid on top of the adhesive layer 2, requiring the complete overlap of the adhesive layer 2 and the rubber layer 3.

[0133] Pre-press forming: After laying the rubber layer 3, place it in a 200t press at a temperature of 23 ± 5°C, close the mold for pre-pressing, and pre-press for 20 minutes.

[0134] Curing and bonding: After pre-pressing for 20 minutes, raise the temperature for curing. The required curing temperature is 150°C, the curing time is 40 minutes, and the curing pressure is 12 MPa.

[0135] Comparative Example 2

[0136] Mold cleaning: Clean the mold with a mold cleaner. After cleaning the mold surface, apply a release agent to the mold surface with a clean gauze.

[0137] Preparation of plastic film 1: Cut plastic film 1 into an appropriate size according to Tooling A. Cut the rubber layer 3 into an appropriate size using Tooling B. Use a 1.5-inch brush to dip a small amount of cleaning agent and clean the surface of the sodium naphthalene layer of plastic film 1 to ensure that there are no other impurities on the surface of plastic film 1. After standing for 5 minutes, set it aside. Use a 1.5-inch brush to dip a small amount of roller coating adhesive and brush it on one side of the sodium naphthalene-treated layer of plastic film 1 to ensure that the adhesive is evenly coated and there is no missed brushing.

[0138] Preparation of rubber layer 3: Use a mill, control the thickness within 3.8 - 4.2 mm, and there should be no bubbles, wrinkles or other defects on the surface. Cut it into the same size using Tooling B and lay it above adhesive layer 2. For the preparation of rubber layer 3, the rubber type can be natural rubber or nitrile rubber. Through the methods of mixing and milling, add fillers for mixing and forming. Control the thickness between 3.8 mm and 4.2 mm, cut it into the same size using Tooling B, and lay it above adhesive layer 2, requiring that adhesive layer 2 and rubber layer 3 completely overlap.

[0139] Pre-press forming: After laying the rubber layer 3, place it in a 200t press at a temperature of 23 ± 5°C, close the mold for pre-pressing, and pre-press for 20 minutes.

[0140] Curing and bonding: After pre-pressing for 20 minutes, raise the temperature for curing. The required curing temperature is 150°C, the curing time is 40 minutes, and the curing pressure is 12 MPa.

[0141] Comparative Example 3

[0142] Mold cleaning: Clean the mold with a mold cleaner. After cleaning the mold surface, apply a release agent to the mold surface with a clean gauze.

[0143] Preparation of plastic film 1: Cut plastic film 1 into an appropriate size according to Tooling A. Use a 1.5-inch brush to dip a small amount of cleaning agent and clean the surface of the sodium naphthalene layer of plastic film 1 to ensure that there are no other impurities on the surface of plastic film 1. After standing for 5 minutes, set it aside.

[0144] The preparation of the rubber layer 3 is carried out using an open mill, with the thickness controlled at 3.8 - 4.2 mm. Bubbles, wrinkles and other defects are not allowed on the surface. It is cut into the same size using Tooling B and laid on top of the rubber layer 2. For the preparation of the rubber layer 3, the rubber type can be natural rubber or nitrile rubber. Through the methods of internal mixing and open mixing, fillers are added for mixing and forming. The thickness is controlled between 3.8 mm and 4.2 mm, and it is cut into the same size using Tooling B and laid on top of the rubber layer 2, requiring the complete overlap of the rubber layer 2 and the rubber layer 3.

[0145] Pre-press forming: After laying the rubber layer 3, place it in a 200t press at a temperature of 23 ± 5 °C for mold closing and pre-pressing for 20 minutes.

[0146] Curing and bonding: After pre-pressing for 20 minutes, raise the temperature for curing. The required curing temperature is 150 °C, the curing time is 40 minutes, and the curing pressure is 12 MPa.

[0147] In step S8, compare the bonding strength between the plastic film 1 and the rubber in the elastomeric support pad material with that of the plastic film 1 and the rubber using traditional adhesives. Cut the obtained specimens into three specimens each with a length of 200 mm, a width of 25 mm, and a thickness of 5 mm using a utility knife, place them in a universal tensile testing machine, and test the 180° peel strength of the samples. The performance is as shown in the following table.

[0148] Table 1. Performance comparison between the examples and the comparative examples

[0149]

[0150] It can be seen from Table 1 that in Comparative Examples 1 - 2, traditional adhesives were used to bond the rubber layer 3 and the plastic film 1, and the bonding strengths after forming were 0.9 Mpa and 2.5 Mpa respectively. While in Examples 1 - 3, the bonding strengths between the rubber layer 3 and the plastic film 1 without traditional adhesives in the technical solution of the present invention are significantly higher than those of the traditional processing solutions, reaching 4.5 Mpa, 5.3 Mpa, and 6.4 Mpa respectively.

[0151] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. An adhesive-free compounding molding method, characterized in that: The specific steps include: S1: Mould cleaning; S2: cutting, cutting the plastic film (1) to a set size using tool A, and cutting the rubber layer (3) and the adhesive layer (2) to a set size using tool B, wherein the thickness of the adhesive layer (2) is in the range of 0.58 to 0.64 mm, and the surface dyne value of the plastic film 1 after being treated with sodium naphthalene is above 50; S3: Laying the rubber layer (3) and the adhesive layer (2), the adhesive layer (2) and the rubber layer (3) are laid in sequence on the surface of the plastic film (1), and the distance between the rubber layer (3) and the adhesive layer (2) and the edge of the plastic film (1) is 2-8 mm; S4: inspecting the rubber layer (3) and the adhesive layer (2), and cutting open any bulges or bubbles on the surface of the rubber layer (3) and the adhesive layer (2), and removing any impurities; S5: Pre-forming in a press, after the adhesive layer (2) is laid, it is placed in a press and pressed for more than 20 minutes before being taken out; S6: before curing begins, the plastic film (1) attached to the rubber layer (3) and the adhesive layer (2) is placed in the middle of the mold, with the plastic film (1) being 2-6 mm away from the edge of the mold cavity; S7: After the mold is installed, slowly close the mold, preheat for 1-6 minutes, close the mold and maintain pressure. During this period, observe whether the mold is abnormal, and then adjust the oven curing temperature to 100-200℃ and the curing time to 30-50 minutes; S8: Demolding. After curing is completed, the product is completely removed from the mold to obtain a high-quality elastomer support pad material.

2. The adhesive-free compounding molding method according to claim 1, characterized in that: In step S2, the plastic film (1) is one of a polyester film, a polyethylene film, a polypropylene film and a polytetrafluoroethylene film, and the plastic film (1) is drawn by pultrusion or curling.

3. The adhesive-free compounding molding method according to claim 1, characterized in that: The plastic film (1) is cut to a set size using tooling A, the surface of the plastic film (1) needs to be treated with sodium naphthalene, and the thickness is between 0.4 mm and 0.6 mm.

4. The adhesive-free compounding molding method according to claim 1, characterized in that: In step S2, the adhesive layer (2) is a kind of chloroprene rubber or brominated butyl rubber. The adhesive layer (2) is processed by a precision calender, and bubbles, wrinkles and other defects are not allowed on the surface. After being produced, it is cut to a set size by using a B tooling, and rolled up for storage.

5. The adhesive-free compounding molding method according to claim 4, characterized in that: The steps for preparing the adhesive layer (2) are as follows: ST1: The rubber type of the rubber layer (2) is chloroprene rubber, and the fillers used include carbon black, white carbon black, tackifier, accelerator CZ and sulfur, with a ratio of 50-100 parts of chloroprene rubber, 20-60 parts of carbon black, 10-30 parts of white carbon black, 0-30 parts of tackifier, 0-5 parts of accelerator CZ and 0-5 parts of sulfur; ST2: Use internal mixer and open mixer for mixing and molding, the speed is 35 / min, the mixing temperature is 70℃, and the debinding temperature does not exceed 120℃; ST3: After refining and molding, the mixed rubber is sent to a four-roll calender for compression molding. The speed ratio of AB and BC rollers is controlled at 0.9, the speed ratio of CD roller is controlled at 1, the distance between AB rollers is controlled at 0.7mm, the distance between BC rollers is controlled at 0.55mm, and the distance between CD rollers is controlled at 0.8mm. The total thickness of the film is controlled between 0.58 and 0.64mm and rolled into shape; ST4: The film produced in step ST3 is cut into a set size using tool B to obtain the adhesive layer (2).

6. The adhesive-free compounding molding method according to claim 1, characterized in that: In step S2, the rubber layer (3) is one or more of natural rubber, styrene-butadiene rubber, EPDM rubber, and nitrile rubber, and is refined using an open mill, with a thickness controlled at 3.8 to 4.2 mm. No bubbles, wrinkles, or other defects are allowed on the surface, and the rubber layer (3) is cut to a set size using a B tool.

7. The adhesive-free compounding molding method according to claim 1, characterized in that: In step S2, the length and width dimensions of tooling A are 300 mm×200 mm, and the length and width dimensions of tooling B are 290 mm×190 mm.

8. The adhesive-free compounding molding method according to claim 1, characterized in that: In step S5, the press is a flat-plate vulcanizing press with a specification of 200t, 300t or 400t.

9. The adhesive-free compounding molding method according to claim 1, characterized in that: In step S7, the oven is 2.3 m high and 1.5 m wide, and the oven temperature ranges from 0 to 200°C.

10. The adhesive-free compounding molding method according to claim 1, characterized in that: The method also includes step S9, cutting the elastomeric support pad material in S8 into three samples each with a length of 200 mm, a width of 25 mm, and a thickness of 5 mm, placing the samples in a universal tensile testing machine, and testing the 180° peel strength of the samples.

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