EPDM reclaimed rubber processed from EPDM unvulcanized rubber compound and waste EPDM rubber has excellent resistance to high and low temperature and aging resistance. It is often used alone or in combination with EPDM to produce various types of rubber seals. Strips, to ensure the life of the seals under the premise of reducing production costs; EPDM reclaimed rubber itself has excellent anti-aging properties, but in the production process of seals, it is inevitable to add anti-aging agents, the type and amount of anti-aging agents directly affect the service life of seals .
1. Try to avoid using "toxic" anti-aging agents
Among the many EPDM seals, door and window seals are one of the main products. Whether it is house door and window seals or car door and window seals, it is highly environmentally friendly and tasteless. Anti-aging agents such as anti-aging agent D Although the protective effect is obvious, it is seriously polluting and toxic. It is generally forbidden to be used in the EPDM door and window seals; the anti-aging agent D is not only toxic, but also severely discolors when exposed to light, so all kinds of light-colored three Ethylene-propylene-propylene reclaimed rubber seals must be avoided.
2. EPDM reclaimed rubber seals are commonly used anti-aging agents
In actual production, EPDM/regenerative rubber sealing strips use anti-aging agent MB and anti-aging agent RD. Anti-aging agent MB is a typical non-polluting anti-aging agent, which has good protective effect on thermal oxygen aging and weathering aging. It not only satisfies the basic anti-aging requirements of EPDM door and window seals, but also effectively suppresses the accelerated aging of harmful metal ions; the anti-aging agent RD is a general-purpose amine rubber anti-aging agent, which has obvious protective effect on thermal oxygen aging, generally with other types. Rubber anti-aging agent is used together.
In the production of EPDM reclaimed rubber seals, the anti-aging agent MB/RD is used in combination. In the hot air aging test, the tensile strength and elongation at break of the rubber are very small.
3. Pay attention to the effect of anti-aging agent on the compression performance of EPDM reclaimed rubber seals
The rubber anti-aging agent MB and the anti-aging agent RD can significantly delay the aging time of the EPDM reclaimed rubber seal strip in a proper ratio, but in actual production, the EPDM rubber compression set will follow the anti-aging agent MB/RD. The increase and increase, the more the amount of anti-aging agent MB, the worse the compression-resistant permanent deformation of the EPDM reclaimed rubber compound. Usually, when EPDM/recycled rubber is used together to produce a rubber seal, 2 parts of antioxidant MB is used together with 1.5 parts of antioxidant RD.
When using EPDM reclaimed rubber to produce rubber sealing strips, it is necessary to select the appropriate type of anti-aging agent, and reasonably adjust the type and amount of compounding agent in the reclaimed rubber sealing strip formula, and reduce the compression permanent deformation of EPDM reclaimed rubber sealing strip. Improve the anti-aging properties of reclaimed rubber and prolong the service life of EPDM reclaimed rubber seals.