A variety of rubber blends for the manufacture of rubber grommets
Two or more different rubbers or rubbers are blended with a synthetic resin by mechanical force to produce a combination of various rubber grommets called rubber mechanical blends or rubber. The rubber blend combines the properties of a component polymer with a new rubber material that is different from the component polymer and can also be referred to as a rubber alloy. Blending has become an effective and important means of rubber modification.
The purpose and significance of rubber blending-Improve rubber performance and processability
The main purpose of rubber blending is to improve the performance of existing rubber grommets. For example, natural rubber is widely used because of its good comprehensive mechanical properties and processing properties, but its thermal aging resistance, ozone aging resistance, oil resistance and chemical resistance are not good. Most of the synthetic rubbers have poor processing properties and unsatisfactory mechanical properties, which often cause difficulties in production. These synthetic rubbers are blended with natural rubber and have complementary properties, which in particular improves the processability of synthetic rubber. The rubber parts of the tires are widely used in combination with NR, SER, BR, etc., and the V-shaped tape is made of 90/10 CR/NR blend rubber. NR not only improves the sticking phenomenon of CR in mixing and rolling, It also improves the low temperature resistance of the tape.
Synthetic rubbers are blended with each other to improve performance. If the inner tube is made of a single HR, although the airtightness is good, the use of a long time will cause defects such as softening of the carcass, sticking of the tire, and enlargement of the inner tube. If 1IR is blended with a small amount of EPDM, it can be effective. The above defects are overcome, which is attributed to the structural change mainly caused by crosslinking after the thermal aging of EPDM. A small amount of EPDM glue can increase the amount of carbon black and softening oil, and also improve the surface smoothness and shrinkage of the extruded semi-finished inner tube.
The blending of special synthetic rubber with general-purpose or special synthetic rubber can effectively maintain the performance of rubber, and can effectively reduce the cost of grommets production and improve the utilization rate of special rubber. Such as the blending of fluororubber and acrylate rubber, the blending of silicone rubber and EPDM rubber, and the blending of fluororubber and butyl rubber.
The blending of rubber and synthetic resin is another important way to achieve rubber modification. The performance advantages of synthetic resins are high strength, excellent heat aging resistance, and resistance to various chemical mediators. These are precisely the lack of certain synthetic rubbers. The rubber is blended with a small amount of synthetic resin to improve certain properties of the rubber, thereby increasing the use value of the rubber and broadening its application fields. The most successful and successful example in this regard is the blending of NBR and PVC. The blends are now widely used in the production of various oil resistant chemical resistant, ozone resistant rubber grommets.