EPDM rubber has excellent resistance to high and low temperature and anti-aging properties. EPDM reclaimed rubber inherits the basic performance characteristics of EPDM rubber. Therefore, many rubber products manufacturers use EPDM rubber and EPDM reclaimed rubber. Production of solid sealing strips, while maintaining a good sealing effect while reducing production costs, solid sealing strips of different hardness can be achieved by adjusting EPDM rubber / reclaimed rubber and formula; Xiaobian today is different from everyone The difference in formulation of the hardness of the EPDM solid seal.
1. Design of the coordination system in EPDM sealing strip
(1) Vulcanization system: The general hardness of the EPDM rubber/recycled rubber solid sealing strip is selected from the sulfur vulcanization system. In combination with different types of accelerators, the solid sealing strip with a Shore hardness of about 40 degrees can be selected to promote. The agent M/BZ/PZ/TMTD is used together. The EPDM sealing strip of about 50 degrees can increase the accelerator TDEDC. The 60 degree solid sealing strip can choose sulfur and accelerator EZ/CZ/TMTD/TDEDC; when the sealing strip hardness demand reaches 80 degrees A peroxide cure system is then required.
(2) Reinforcement filling system: In the formulation of EPDM rubber/recycled rubber, the reinforcing agent and filler are one of the main factors affecting the solid sealing strip. The low-hardness EPDM solid sealing strip can be used in the fast-pressing formula. Carbon black and calcium carbonate, high hardness EPDM rubber seal can be used with ultra-fine calcium carbonate, solid seal with Shore hardness of about 69 degrees can be combined with semi-reinforcing carbon black, high hardness EPDM The rubber sealing strip is selected to be used in combination with carbon black, light calcium carbonate and clay.
(3) In the actual production, the rubber softening oil will also affect the hardness of the rubber compound. When adjusting the hardness of EPDM, the rubber oil dosage can be reduced as much as possible; the paraffin oil has less volatile matter and high flash point, and the volatile matter is small at high temperature, which can be used in In the production of solid sealing strips, the rubber processing technology is improved while reducing the cost of the rubber compound.
2. There are many kinds of EPDM and EPDM reclaimed rubber on the market. Different products have different hardness. Generally, EPDM/Recycled rubber is used to produce low hardness solid sealing strips. The solid seal of hardness uses EPDM raw rubber and reclaimed rubber with high hardness.
In the production of solid sealing strips, the hardness can measure the sealing effect of the sealing strip to a certain extent. The formula design of the EPDM solid sealing strip is different for different occasions; the sealing strip manufacturer should choose the appropriate hardness according to its own needs. Propylene rubber and EPDM reclaimed rubber, determine the type and amount of compounding agent in various compounding systems, and increase the amount of EPDM recycled rubber as much as possible to meet the requirements of solid sealing strips, and reduce more production costs.