Butyl reclaimed rubber has excellent air tightness, water tightness, heat resistance and chemical stability, completely retains the basic performance characteristics of butyl rubber, and is widely used in butyl rubber products. In the actual application process, many butyl rubber/recycled rubber products are required to have excellent compression set resistance to ensure the product performance; then how can rubber products manufacturers reduce the compression deformation of butyl rubber?
The permanent deformation of rubber is essentially the creep phenomenon of the rubber under the action of time stress. The compression set of each butyl rubber or butyl reclaimed rubber is constant, and the butyl with high viscosity is usually compared. It is better to resist compression and permanent deformation; rubber manufacturers want to improve the compression-resistant permanent deformation of butyl rubber or butyl reclaimed rubber, and can only start from the compounding agent and production process conditions.
1. Use large particle size reinforcing agent or filler
When carbon black is used in butyl reclaimed rubber or butyl rubber, the carbon black with a rough surface and a large particle size can form a carbon black gel with the butyl rubber compound, thereby increasing the tensile strength of the vulcanized rubber. , the properties of tensile stress, hardness and wear resistance, the rubber has better compression and permanent deformation resistance; the better the compatibility with butyl rubber or reclaimed rubber, the reinforcing effect of rubber filler in butyl vulcanizate The more realistic, the butyl vulcanizate can be increased to a certain extent to achieve the purpose of reducing compression set.
Studies have shown that the use of large particle size fine particles for thermal cracking of carbon black in butyl rubber, butyl vulcanizate has the lowest compression set; similarly, the compression set of butyl rubber filled with large particle size filler is generally less than Small size filler filled compound.
2. Choose a suitable vulcanization system
The compression set of the rubber compound is directly related to the vulcanization system. When rubber products are produced by using butyl rubber or butyl reclaimed rubber, the butyl vulcanizate after sulfur vulcanization has a large compression set, and the vulcanized rubber vulcanized with diethyldithiocarbamate has better compression set resistance. . In actual production, the tensile strength of bismuth dithiocarbamate vulcanizate is smaller than that of sulfur vulcanizate, and it may be used together.
3. Properly increase the vulcanization temperature or extend the curing time
Theoretically, the elasticity of the vulcanizate can be reduced to reduce the compression set of the butyl vulcanizate, and the vulcanization temperature or the vulcanization time can be appropriately increased within a certain range, thereby promoting the formation of a crosslinked network in the butyl vulcanizate and increasing the crosslink density of the vulcanized rubber. Ultimately, the purpose of reducing compression set is achieved. When rubber products are produced using butyl rubber or butyl reclaimed rubber, rubber manufacturers can appropriately increase the vulcanization temperature according to the processing temperature of the butyl rubber, improve the compression set resistance of the rubber compound, and improve the vulcanization efficiency to a certain extent.
When the butyl rubber or butyl reclaimed rubber product formulation contains a tackifying system, the rubber product manufacturer can further improve the compression-resistant permanent deformation of the butyl rubber product by adjusting the ratio of the rubber oil to the tackifier, and the later small series will continue to be You explore a variety of techniques in the production of butyl rubber products.