A method for manufacturing high-density and high-elastic microporous EPDM foam
By finely controlling process parameters and using specific raw materials, the problem of difficult to improve the density and elasticity of EPDM foamed materials is solved, high density, high elasticity and wear resistance are achieved, and the material is given unique functionality.
Patent Information
- Application Number
- CN202510020832.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-07
- Publication Date
- 2025-04-04
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
In the prior art, when manufacturing EPDM foaming materials, it is difficult to accurately control the kneading, vulcanization and foaming process parameters, resulting in the difficulty of the material's density and elasticity to reach a high level, and there are problems such as uneven density, insufficient elasticity, limited aging resistance, and insufficient wear resistance.
The high-density and high-elastic microporous foaming EPDM foaming manufacturing method includes material preparation, fine mixing, optimized flax fiber treatment, efficient composite, intelligent vulcanization and supercritical foaming. By precisely controlling process parameters and using specific raw materials, the high density and high elasticity of the material are ensured.
It realizes the high density and elasticity of EPDM foamed materials, provides better support and resilience, extends the service life of the material, enhances wear resistance, and gives the material unique functions such as self-cleaning, antistatic, and biodegradable.
Smart Images
Figure CN119751958A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of EPDM foaming, in particular to a method for manufacturing high-density and high-elastic microporous EPDM foaming. Background Art
[0002] EPDM rubber is a terpolymer of ethylene, propylene and non-conjugated dienes. Because its main chain is composed of chemically stable saturated hydrocarbons and only contains unsaturated double bonds in the side chains, it has excellent aging resistance such as ozone resistance, heat resistance, and weather resistance. It can be widely used in automotive parts, building waterproof materials, wire and cable sheaths, heat-resistant hoses, tapes, automotive seals and other fields.
[0003] When manufacturing EPDM foam materials, the existing technology often finds it difficult to accurately control the mixing, vulcanization and foaming process parameters, resulting in the difficulty in achieving a high level of density and elasticity of the material. Specifically, it is manifested as: Uneven density: Under the existing technology, the density of the foam material may fluctuate greatly and cannot provide stable support force under the same volume. This may cause the product to partially collapse or deform during use, affecting its performance and service life. Insufficient elasticity: The foam material prepared by the existing technology has poor resilience and is difficult to quickly return to its original state after being subjected to external force. This will reduce the performance and user experience of the product in some application fields with high elasticity requirements, such as high-end sports equipment and automotive shock-absorbing components.
[0004] At the same time, the effect of anti-aging additives is limited: the anti-aging additives used in the prior art may not provide sufficient protection, making the foam material prone to cracking, hardening, etc. during long-term use. This will not only reduce the performance of the material, but also shorten the service life of the product; lack of reinforcing materials: the prior art may not use reinforcing materials such as flax fiber, or the reinforcing materials used have poor bonding and compatibility with rubber. This makes the foam material lack wear resistance and is prone to wear in application scenarios with frequent friction, resulting in performance degradation and increased demand for replacement. Summary of the invention
[0005] In order to overcome the above technical problems, the purpose of the present invention is to provide a high-density and high-elastic microporous foamed EPDM foaming method to solve the problem that the current foamed EPDM foaming method mentioned in the above background technology is difficult to accurately control the mixing, vulcanization and foaming process parameters, resulting in the density and elasticity of the material being difficult to reach a high level.
[0006] To achieve the above object, the present invention provides the following technical solution: a method for producing high-density and high-elastic microporous EPDM foam, comprising the following steps:
[0007] (1) Material preparation: Select high-quality EPDM rubber, as well as nano-silica, new anti-aging additives, plant-derived stearic acid substitutes, active zinc oxide, environmentally friendly peroxide initiators, natural sulfur, high-efficiency accelerators, bio-based flame retardants, degradable rubber filler oil, green foaming agents, natural foaming aids, and specially treated flax fibers;
[0008] (2) Mixing: Mix the EPDM rubber in an advanced internal mixer at a specific temperature range of 55-65°C and a rotation speed of 85-95 r / min to an ideal viscosity flow state, and then add nano-silica, a new anti-aging additive, a plant-derived stearic acid substitute, active zinc oxide and an environmentally friendly peroxide initiator in sequence for 25-35 minutes; then add natural sulfur and a high-efficiency accelerator and mix on an improved open mixer. After ensuring uniform mixing, perform a thin-pass sheeting operation, and leave the mixed rubber for 18-22 hours;
[0009] (3) Flax fiber optimization treatment: A unique surface treatment technology is used on flax fiber to greatly improve its bonding strength and compatibility with EPDM rubber;
[0010] (4) Efficient compounding: Add the treated flax fiber to the stored mixed rubber and perform innovative compounding again to fully and evenly compound the flax fiber with EPDM rubber;
[0011] (5) Intelligent vulcanization: The composite rubber material is placed on the mold plate of an intelligent high-temperature vulcanizer for vulcanization. The vulcanization temperature is strictly controlled at 145-155°C, the vulcanization pressure is accurately set to 65-75kN, and the vulcanization time is 25-55min to obtain EPDM rubber material with excellent aging resistance.
[0012] (6) Foaming preparation: Carefully cut the aging-resistant EPDM rubber material into strips of specific size;
[0013] (7) Foaming: Use supercritical foaming equipment for foaming. When the foaming temperature reaches 50-60°C, add the rubber sample into the cavity of the supercritical foaming equipment, introduce environmentally friendly gas to replace the air in the cavity, pressurize to 12-18MPa, fully saturate for 35-45 minutes and then release the pressure to obtain a high-density, high-elasticity microporous foamed EPDM foam material with unique properties.
[0014] Preferably, the ratio of the EPDM rubber, nano-silicon dioxide, new anti-aging additive, plant-derived stearic acid substitute, active zinc oxide, environmentally friendly peroxide initiator, natural sulfur, and high-efficiency accelerator is 100g:(12-22)g:(3-8)g:(1.2-2.2)g:(2-3)g:(2.5-3.5)g:(1.5-2.5)g:(0.6-1)g.
[0015] Preferably, the ratio of the EPDM rubber to the flax fiber is 100g:(8-15)g.
[0016] Preferably, the bio-based flame retardant is prepared by the following method: reacting a specific bio-based monomer, a natural organic acid and a plant extract under specific conditions, and after the reaction is completed, a series of treatments are performed to obtain the bio-based flame retardant.
[0017] Preferably, the green foaming agent is a recyclable gas or a foaming agent extracted from plants.
[0018] Preferably, the natural auxiliary foaming agent is an organic acid or alcohol substance extracted from natural products, and the unique surface treatment technology includes treating the flax fiber with a natural coupling agent and combining it with a specific plasma treatment method.
[0019] Preferably, the manufacturing method also includes using an advanced intelligent control system during the vulcanization and foaming process to monitor multiple key parameters in real time, and automatically adjust the process parameters according to an independently developed algorithm to ensure high stability and consistency of product quality, and the foaming material has one or more unique functions of self-cleaning, antistatic, biodegradable, shape memory or environmental responsiveness.
[0020] Compared with the prior art, the present invention has the following beneficial effects:
[0021] 1. By precisely controlling the mixing, vulcanization and foaming process parameters and using a specific ratio of raw materials, the EPDM foam material manufactured by the present invention has higher density and elasticity. Compared with the prior art, it can provide better support and resilience under the same volume, and is suitable for application fields with higher performance requirements, such as high-end sports equipment, automotive shock-absorbing parts, etc.;
[0022] 2. The use of new anti-aging additives and intelligent vulcanization process make the foam material of the present invention have excellent anti-aging performance. During long-term use, it can maintain stable performance and is not prone to cracking, hardening and other phenomena, thus extending the service life of the product. Compared with the prior art, the foam material of the present invention has more outstanding anti-aging performance in harsh environments;
[0023] 3. The addition of flax fiber and special surface treatment technology significantly improve the wear resistance of the foam material. Compared with the prior art, the material of the present invention exhibits better durability in application scenarios with frequent friction, reducing the performance degradation and replacement requirements caused by wear;
[0024] 4. The foaming material of the present invention has multiple unique functions such as self-cleaning, antistatic, biodegradable, shape memory or environmental responsiveness, which are generally not available in the prior art and provide more possibilities and advantages for product applications. For example, the self-cleaning function can reduce cleaning costs and time, the antistatic function improves product safety, the biodegradable property meets environmental protection requirements, and the shape memory and environmental responsiveness provide a basis for the development of smart materials. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 It is a schematic diagram of the overall process steps of the present invention. DETAILED DESCRIPTION
[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0027] See also Figure 1The present invention provides an embodiment: a method for manufacturing high-density, high-elasticity microporous EPDM foam, comprising the following steps: (1) material preparation: selecting high-quality EPDM rubber, and preparing nano-silicon dioxide, a new anti-aging additive, a plant-derived stearic acid substitute, active zinc oxide, an environmentally friendly peroxide initiator, natural sulfur, a high-efficiency accelerator, a bio-based flame retardant, a degradable rubber filling oil, a green foaming agent, a natural foaming aid, and specially treated flax fiber; (2) mixing: mixing the EPDM rubber at a specific temperature; and The mixture is mixed in an advanced internal mixer with a temperature range of 55-65°C and a rotation speed of 85-95r / min until the ideal viscosity is reached. Nano-silicon dioxide, a new anti-aging additive, a plant-derived stearic acid substitute, active zinc oxide and an environmentally friendly peroxide initiator are added in sequence for 25-35 minutes. Natural sulfur and a high-efficiency accelerator are then added and mixed on an improved open mixer. After ensuring uniform mixing, a thin-pass sheeting operation is performed and the mixed rubber is left for 18-22 hours. (3) Optimization of flax fiber treatment: The unique surface treatment technology is used to greatly improve its bonding strength and compatibility with EPDM rubber; (4) High-efficiency compounding: the treated flax fiber is added to the stored mixed rubber, and then innovatively mixed again to make the flax fiber and EPDM rubber fully and evenly compounded; (5) Intelligent vulcanization: the composite rubber material is placed on the mold plate of the intelligent high-temperature vulcanizer for vulcanization. The vulcanization temperature is strictly controlled at 145-155°C, the vulcanization pressure is accurately set to 65-75kN, and the vulcanization time is 25-55min. Obtain EPDM rubber material with excellent aging resistance; (6) Foaming preparation: Carefully cut the aging-resistant EPDM rubber material into strips of specific size; (7) Foaming: Use supercritical foaming equipment for foaming. When the foaming temperature reaches 50-60°C, add the rubber strips into the cavity of the supercritical foaming equipment, introduce environmentally friendly gas to replace the air in the cavity, pressurize to 12-18MPa, fully saturate for 35-45 minutes, and then release the pressure to obtain a high-density, high-elasticity, microporous foamed EPDM foam material with unique properties.
[0028] The proportions of EPDM rubber, nano-silicon dioxide, new anti-aging additives, plant-derived stearic acid substitutes, active zinc oxide, environmentally friendly peroxide initiators, natural sulfur, and high-efficiency accelerators are as follows:
[0029] 100g: (12-22)g: (3-8)g: (1.2-2.2)g: (2-3)g: (2.5-3.5)g: (1.5-2.5)g: (0.6-1)g.
[0030] The ratio of EPDM rubber to flax fiber is 100g:(8-15)g. This ratio configuration has the following main functions:
[0031] 1. Strength improvement: When flax fiber is compounded with EPDM rubber within this ratio range, the strength of the foamed material can be effectively improved. Flax fiber has high tensile strength and modulus, can bear part of the external force, and reduce the stress concentration of the rubber matrix. For example, when subjected to tensile or compressive loads, flax fiber can prevent the expansion of cracks and improve the overall strength of the material. When the ratio is 100g:8g, the strength of the material has been significantly improved. With the increase of the flax fiber ratio, the strength is further improved. However, when the ratio reaches 100g:15g, the strength improvement tends to be flat. This is because too much flax fiber may cause fiber agglomeration, affecting the uniformity of the material, thereby reducing the strength improvement effect.
[0032] 2. Enhanced wear resistance: The addition of flax fiber can also improve the wear resistance of the foam material. Flax fiber has a high hardness and can resist friction and wear. After compounding with EPDM rubber, flax fiber is distributed in the rubber matrix to form a structure similar to a reinforced skeleton, which can effectively resist external wear. In practical applications, this improvement in wear resistance can extend the service life of the foam material, especially in some occasions with frequent friction, such as soles, seals, etc.
[0033] 3. Maintain high elasticity: EPDM rubber itself has good elasticity, and the addition of flax fiber within a certain proportion range will not significantly reduce the elasticity of the material. On the contrary, due to the good combination of flax fiber and rubber matrix, when subjected to external force, flax fiber can play a certain supporting role, making the material recover more quickly and completely when it is subjected to external force. When the ratio is 100g: (8-12)g, the elasticity of the foaming material remains basically unchanged, and even improves in some cases. This is because the presence of flax fiber can limit the excessive deformation of rubber molecules and improve the resilience of the material;
[0034] 4. Elastic stability: As the proportion of flax fiber increases, the elastic stability of the foam material will also be improved. During long-term use, the foam material may be repeatedly subjected to various external forces, resulting in a decrease in elasticity. The addition of flax fiber can enhance the structural stability of the material and reduce fatigue damage to rubber molecules, thereby maintaining the elastic stability of the material. For example, in some application fields that need to withstand dynamic loads for a long time, such as automotive shock absorbers, sports equipment, etc., this improvement in elastic stability is particularly important.
[0035] Bio-based flame retardants are prepared by the following method: reacting specific bio-based monomers, natural organic acids and plant extracts under specific conditions, and then undergoing a series of treatments to obtain bio-based flame retardants. Sources and types: Bio-based monomers can be derived from a variety of renewable resources, such as vegetable oils, sugars, lignin, etc. For example, using vegetable oil as a raw material, fatty acid ester bio-based monomers can be obtained through chemical modification; using sugars as a raw material, alcohol and aldehyde bio-based monomers can be obtained through fermentation or chemical conversion. Different bio-based monomers have different chemical structures and properties, and can be selected according to the requirements of flame retardants. Mechanism of action: Bio-based monomers play a key role in flame retardants. They can be combined with natural organic acids and plant extracts through chemical reactions to form polymers with flame retardant properties. For example, some bio-based monomers contain flame retardant elements such as phosphorus and nitrogen, which can form a heat-insulating and oxygen-isolating carbon layer during combustion to prevent the spread of flames. At the same time, the structure of bio-based monomers can also affect the thermal stability and flame retardant effect of flame retardants.
[0036] Green foaming agents are foaming agents that are recycled gases or extracted from plants.
[0037] The natural foaming agents are organic acids or alcohols extracted from natural products. The unique surface treatment technology includes treating the flax fibers with natural coupling agents combined with a specific plasma treatment method.
[0038] The manufacturing method also includes the use of advanced intelligent control systems during the vulcanization and foaming processes to monitor multiple key parameters in real time and automatically adjust process parameters based on independently developed algorithms to ensure high stability and consistency of product quality. The foamed material has one or more unique functions of self-cleaning, antistatic, biodegradable, shape memory or environmental responsiveness.
[0039] Working principle: Select high-quality EPDM rubber as the main base material, which has good aging resistance, chemical corrosion resistance and low-temperature flexibility, etc., providing basic rubber properties for foaming materials; prepare nano-silicon dioxide to enhance rubber strength and wear resistance and help form a uniform microporous structure; new anti-aging additives improve the long-term stability of EPDM rubber; plant-derived stearic acid substitutes play a lubricating role and are environmentally friendly; active zinc oxide improves rubber vulcanization efficiency and heat resistance; environmentally friendly peroxide initiators induce cross-linking reactions of rubber molecules during the subsequent vulcanization process; natural sulfur and high-efficiency accelerators jointly promote rubber vulcanization reactions so that rubber molecules form a three-dimensional cross-linked network structure to improve material strength and stability; bio-based flame retardants are made of specific It is prepared by the reaction of bio-based monomers, natural organic acids and plant extracts, which plays a flame retardant role in foaming materials and improves material safety; degradable rubber filler oil reduces the hardness of the material, improves processing performance, and is degradable and meets environmental protection requirements; green foaming agents use recyclable gases or foaming agents extracted from plants to generate gas during the foaming process to form a microporous structure, making the material lightweight, heat-insulating, and cushioning. Natural auxiliary foaming agents are extracted from natural products to assist the foaming agent in generating gas to regulate the foaming process and microporous structure; specially treated flax fibers have high strength and wear resistance, and after being compounded with EPDM rubber, they improve the strength and wear resistance of the foaming material while reducing dependence on synthetic fibers; in a specific temperature range of 55-65°C and a rotation speed of 85-95 In an advanced internal mixer with a speed of 1000 r / min, EPDM rubber is heated and mixed to an ideal viscous flow state. Nano-silica, a new anti-aging additive, a plant-derived stearic acid substitute, active zinc oxide and an environmentally friendly peroxide initiator are added in sequence for a mixing time of 25-35 minutes. Natural sulfur and a high-efficiency accelerator are then added for mixing on an improved open mixer. After mixing evenly, a thin-pass sheeting operation is performed. The mixed rubber is left for 18-22 hours to allow the rubber molecules to have enough time to relax and adjust, thereby improving the rubber processing performance and vulcanization effect. A unique surface treatment technology is used for flax fibers, including the use of natural coupling agents and a specific plasma treatment method to improve the bonding and compatibility with EPDM rubber. The treated flax fibers are added to the stopped The mixed rubber is innovatively mixed again to fully combine the flax fiber and EPDM rubber to form a uniform composite material, which improves the strength and wear resistance of the foaming material and reduces the dependence on synthetic fibers; the composite rubber material is placed on the mold plate of the intelligent high-temperature vulcanizer for vulcanization. The vulcanization temperature is strictly controlled at 145-155°C, the vulcanization pressure is accurately set to 65-75kN, and the vulcanization time is 25-55min. During the vulcanization process, an advanced intelligent control system is used to monitor multiple key parameters in real time. The process parameters are automatically adjusted according to the independently developed algorithm to ensure the stability and consistency of the vulcanization process to obtain EPDM rubber materials with excellent aging resistance; the aging-resistant EPDM rubber material is carefully cut into splines of specific sizes to prepare for the foaming process;Supercritical foaming equipment is used for foaming. When the foaming temperature reaches 50-60℃, the rubber sample is added to the cavity of the supercritical foaming equipment. Environmentally friendly gas is introduced to replace the air in the cavity. The pressure is increased to 12-18MPa and fully saturated for 35-45 minutes before decompression. At this time, the foaming agent quickly releases gas to form a uniform microporous structure inside the rubber material to obtain a high-density, high-elastic microporous foamed EPDM foam material with unique properties; the foaming material has one or more unique functions of self-cleaning, anti-static, biodegradable, shape memory or environmental responsiveness. These functions are achieved by adding specific additives to the material or using special treatment methods. The self-cleaning function allows the surface of the material to automatically clean under certain conditions, keeping the material clean and beautiful. The anti-static function prevents the material from generating static electricity during use, improving the safety and reliability of the material. The biodegradable function allows the material to gradually decompose in the natural environment after use, reducing pollution to the environment. The shape memory function allows the material to return to its original shape under certain conditions after being deformed by external force. It is suitable for some application fields that require shape memory. The environmental responsiveness function allows the material to automatically adjust its performance according to environmental changes, such as temperature responsiveness and humidity responsiveness, etc., to improve the adaptability and practicality of the material. ;
[0040] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.
Claims
1. A method for producing high-density, high-elasticity microporous EPDM foam, characterized in that: The following steps are involved: (1) Material preparation: Select high-quality EPDM rubber, as well as nano-silica, new anti-aging additives, plant-derived stearic acid substitutes, active zinc oxide, environmentally friendly peroxide initiators, natural sulfur, high-efficiency accelerators, bio-based flame retardants, degradable rubber filler oil, green foaming agents, natural foaming aids, and specially treated flax fibers; (2) Mixing: Mix the EPDM rubber in an advanced internal mixer at a specific temperature range of 55-65°C and a rotation speed of 85-95 r / min to an ideal viscosity flow state, and then add nano-silica, a new anti-aging additive, a plant-derived stearic acid substitute, active zinc oxide and an environmentally friendly peroxide initiator in sequence for 25-35 minutes; then add natural sulfur and a high-efficiency accelerator and mix on an improved open mixer. After ensuring uniform mixing, perform a thin-pass sheeting operation, and leave the mixed rubber for 18-22 hours; (3) Flax fiber optimization treatment: A unique surface treatment technology is used on flax fiber to greatly improve its bonding strength and compatibility with EPDM rubber; (4) Efficient compounding: Add the treated flax fiber to the stored mixed rubber and perform innovative compounding again to fully and evenly compound the flax fiber with EPDM rubber; (5) Intelligent vulcanization: The composite rubber material is placed on the mold plate of an intelligent high-temperature vulcanizer for vulcanization. The vulcanization temperature is strictly controlled at 145-155°C, the vulcanization pressure is accurately set to 65-75kN, and the vulcanization time is 25-55min to obtain EPDM rubber material with excellent aging resistance. (6) Foaming preparation: Carefully cut the aging-resistant EPDM rubber material into strips of specific size; (7) Foaming: Use supercritical foaming equipment for foaming. When the foaming temperature reaches 50-60°C, add the rubber sample into the cavity of the supercritical foaming equipment, introduce environmentally friendly gas to replace the air in the cavity, pressurize to 12-18MPa, fully saturate for 35-45 minutes and then release the pressure to obtain a high-density, high-elasticity microporous foamed EPDM foam material with unique properties.
2. The method for producing high-density, high-elastic microporous EPDM foam according to claim 1, characterized in that: The ratio of the EPDM rubber, nano-silicon dioxide, new anti-aging additive, plant-derived stearic acid substitute, active zinc oxide, environmentally friendly peroxide initiator, natural sulfur, and high-efficiency accelerator is 100g: (12-22)g: (3-8)g: (1.2-2.2)g: (2-3)g: (2.5-3.5)g: (1.5-2.5)g: (0.6-1)g.
3. The method for producing high-density, high-elastic microporous EPDM foam according to claim 1, characterized in that: The ratio of the EPDM rubber to the flax fiber is 100g:(8-15)g.
4. The method for producing high-density, high-elastic microporous EPDM foam according to claim 1, characterized in that: The bio-based flame retardant is prepared by the following method: reacting a specific bio-based monomer, a natural organic acid and a plant extract under specific conditions, and then performing a series of treatments after the reaction to obtain the bio-based flame retardant.
5. The method for producing high-density, high-elastic microporous EPDM foam according to claim 1, characterized in that: The green foaming agent is a foaming agent that can be recycled gas or extracted from plants.
6. The method for producing high-density, high-elastic microporous EPDM foam according to claim 1, characterized in that: The natural auxiliary foaming agent is an organic acid or alcohol substance extracted from natural products, and the unique surface treatment technology includes using a natural coupling agent to treat flax fibers and combining it with a specific plasma treatment method.
7. The method for producing high-density, high-elastic microporous EPDM foam according to claim 1, characterized in that: The manufacturing method also includes using an advanced intelligent control system during the vulcanization and foaming process to monitor multiple key parameters in real time and automatically adjust the process parameters according to an independently developed algorithm to ensure high stability and consistency of product quality. The foaming material has one or more unique functions of self-cleaning, antistatic, biodegradable, shape memory or environmental responsiveness.