EPDM recycled rubber retains the basic performance characteristics of EPDM original rubber, with high and low temperature resistance, ozone resistance, and good weather resistance. It can be used alone or in combination with EPDM rubber to prepare EPDM gaskets, mainly for sealing, waterproofing, buffering, shock absorption, and insulation. It is widely used in construction, industry, automotive, electrical and other fields, effectively reducing raw material costs. What are the rubber material requirements for EPDM rubber gaskets in different usage scenarios in actual production? How should we design the formula?
1. Common performance requirements for EPDM rubber gaskets
(1) Sealing: EPDM rubber gaskets used for sealing pipe fittings, such as flanges and joints, require the rubber material to have good elasticity and chemical resistance, effectively prevent liquid and gas leakage, and ensure good sealing of pipeline systems.
(2) Shock absorption and buffering: EPDM rubber gaskets require the rubber material to have a certain degree of elasticity and flexibility, giving the gasket good cushioning and shock absorption, improving system stability and comfort.
(3) Waterproof: The rubber gasket used for sealing waterproof pipe fittings requires that the rubber material used has good water resistance and weather resistance, effectively preventing moisture leakage and maintaining the integrity of the system.
(4) Insulation: EPDM rubber gaskets used for sealing electrical fittings are required to have good insulation properties, effectively prevent current leakage and electromagnetic interference, and improve the safety and reliability of electrical equipment.
(5) Chemical corrosion resistance: EPDM rubber sealing gaskets used in chemical and pharmaceutical production require good corrosion resistance of the rubber material. When used for sealing chemical pipe fittings, they can adapt to corrosive media and high temperature and high pressure environments, and resist the erosion of various chemical substances.
2. Reference formula for heat-resistant rubber gaskets produced from EPDM rubber/EPDM recycled rubber
70 parts of EPDM rubber, 30 parts of EPDM recycled rubber, 0.9 parts of anti-aging agent MB, 30 parts of carbon black N330, 20 parts of blended carbon black, 11 parts of high reinforcement white carbon black, 6.3 parts of peroxide DCP, and 1.3 parts of crosslinking agent; Total: 169.5 copies.
3. Key points for formula design of rubber gaskets produced from EPDM recycled rubber
When using EPDM recycled rubber instead of EPDM rubber to produce rubber gaskets, the proportion of EPDM recycled rubber used is generally determined based on the specific performance requirements of the gasket, and some gaskets can be completely made of recycled rubber.
(1) Sulfurization system: When producing rubber gaskets from EPDM recycled rubber, sulfur or peroxide vulcanization systems are generally used. Sulfur vulcanization has a low cost, but attention should be paid to the aging resistance and frost spraying of the vulcanized rubber 2SLYY1220; The cost of peroxide vulcanization system is relatively high, and the vulcanized rubber has good aging resistance but low mechanical strength; If necessary, sulfur and peroxide can be used together.
(2) Reinforcement system: Carbon black is the most commonly used reinforcing agent for EPDM reclaimed rubber, which can endow EPDM vulcanized rubber with good mechanical strength; Light colored EPDM rubber gaskets can be reinforced with white carbon black, and if necessary, a suitable amount of silane coupling agent can be added.
(3) Plasticizing system: Petroleum based plasticizers such as cyclohexane oil have good compatibility with EPDM, but attention should be paid to their impact on the vulcanization system.
(4) Protection system: Adding anti-aging agents can further improve the aging resistance of rubber materials. Compared to EPDM rubber gaskets used in high-temperature environments, heat-resistant anti-aging agents can be used.
The formula for designing EPDM recycled rubber gaskets also needs to consider factors such as cost, processing technology, product performance requirements, and environmental protection; During the mixing process, attention should be paid to the mixing characteristics of various raw materials, such as the liquefaction and agglomeration of sulfur in EPDM, the dispersibility of zinc oxide, and the dispersion of reinforcing agents and fillers; We will discuss with you the vulcanization formula and production process key points of using recycled rubber in different occasions of EPDM rubber gaskets.
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