Nitrile rubber has excellent oil resistance and is widely used in the production of various printing rubber rollers, textile printing and dyeing rubber rollers, soft rubber rollers that require contact with solvents, etc .; but the nitrile rubber itself has poor ozone resistance, and the nitrile rubber roller cannot be used in ozone. Used in high concentration environments. EPDM / recycled rubber has excellent ozone resistance, and many nitrile rubber roller manufacturers use nitrile rubber and EPDM compound together. So is EPDM compound just improving ozone resistance in nitrile rubber rollers, is there any other role? What should I pay attention to when mixing?
1. The role of blending EPDM compound in NBR
EPDM / reclaimed rubber has excellent resistance to high and low temperatures, aging resistance, and ozone resistance. The use of EPDM compound in the nitrile rubber roller formulation can not only improve the ozone resistance of the rubber roller, but also improve it further. The heat resistance of nitrile rubber rollers expands the temperature range of nitrile rubber rollers, improves the performance of nitrile rubber rollers and prolongs their service life; the use of EPDM reclaimed rubber in nitrile rubber rollers can also reduce some raw material costs.
2. Nitrile / EPDM rubber vulcanization properties
The main purpose of blending a small amount of EPDM compound in the nitrile rubber roller is to improve the ozone resistance of the compound. However, due to the low unsaturated content of the EPDM compound and the slow vulcanization rate, the vulcanizing agent can easily react and quickly consume in the unsaturated part of the nitrile rubber phase. The polarity difference between nitrile rubber and EPDM compound is obvious. There is a concentration gradient of vulcanizing agent in the compound rubber. The vulcanizing agent easily diffuses from the low-polarity EPDM rubber phase to the nitrile rubber phase. Therefore, when nitrile rubber and EPDM compound are used together, the design of vulcanization system and vulcanization parameters is unreasonable, and EPDM compound is prone to insufficient vulcanization.
3. Reference formula for blending EPDM compound with nitrile rubber roller
60 parts of nitrile rubber, 20 parts of nitrile reclaimed rubber, 20 parts of EPDM rubber, 10 parts of high wear-resistant carbon black, 1 part of stearic acid, 10 parts of foaming agent, 1.5 parts of sulfur, and 3 parts of accelerator; Total: 125.5 copies.
4. How to coordinate the degree of vulcanization of nitrile / EPDM compound
When using EPDM rubber in nitrile rubber rollers to improve the aging resistance of rubber rollers, in order to coordinate the vulcanization of the rubber compound and ensure that the EPDM rubber is fully vulcanized, rubber product manufacturers can choose the sulfur 2LLYY423 vulcanization system to promote TETD is mainly used together with accelerator M and a small amount of accelerator CZ. The vulcanization and foaming of nitrile foam rubber rollers are carried out at the same time, so rubber product manufacturers also need to adjust the foaming system. It may be possible to use two or more foaming agents in combination, mainly with foaming agent AC, in combination with other types of Foaming agent.
It should be noted that since the vulcanizing agent is easy to migrate from the EPDM rubber phase to the nitrile rubber phase, it is best for rubber product manufacturers to use powdered sulfur or insoluble sulfur to promote sulfur in the nitrile / EPDM compound Evenly dispersed.
Mixing a small amount of EPDM rubber material in the nitrile rubber roller can significantly improve the ozone resistance of the nitrile rubber roller, thereby expanding the scope of use of the rubber roller. Rubber product manufacturers may wish to try it. The overall performance of nitrile rubber rollers has a great impact. Later editors will continue to discuss with you the blending skills and processing skills of blending EPDM rubber materials in nitrile rubber rollers.