Solid silicone rubber is usually a one-component rubber, with cross-linking agent, catalyst, inhibitor and rubber compound mixed together. Mixed rubber is generally formed by high-temperature vulcanization after extrusion. Unlike liquid rubber, which is mostly two-component and has three types: room temperature vulcanization, low-temperature vulcanization, and high-temperature vulcanization.


1. Production process:

It is obtained by kneading silicone rubber raw rubber, white carbon black and other fillers in a kneader, then adding cross-linking agents, catalysts, inhibitors, various colorants, etc. on a two-roller rubber mixer. The resulting rubber is called silicone rubber compound.


2. Physical properties/performance:

1. Before vulcanization (curing), it is "solid". The color depends on the colorant added during mixing. If it is not added, it will be white. The plasticity value is about 200~300;

2. After vulcanization, the transparency without adding colorants is not as good as liquid glue, and the "transmittance" is not higher than 70%. The "rebound value" of mixed rubber with the same "hardness" is generally lower than that of liquid glue, but the "mechanical properties" "But it is generally higher than liquid glue, with "tensile strength" reaching 10~20MPa, "tear strength" reaching 40~60KN/m, and "elongation" generally better than liquid glue with the same hardness. "Vulcanization temperature" is generally between 140 and 180 degrees.


3. Chemical properties/performance:

Mixed rubber raw rubber is a mixture of siloxanes. Its molecules have a chain-like helical structure. The average molecular weight is approximately between 400,000 and 800,000 mPa.s. Its viscosity is directly related to the molecular weight. The molecular weight can be measured with an Ubbelohde viscometer, which is probably the so-called viscosity average molecular weight. The filler nanoscale SiO2 powder (precipitation SiO2 powder) is evenly distributed in the raw rubber to form a crystal-like structure. The hydroxyl groups on the surface of the SiO2 particles form hydrogen bonds with the Si-O bonds of the raw rubber. Each SiO2 particle serves as a core. , stretching out hydrogen bonds in all directions to connect with the raw rubber molecular chain. Countless such structures, plus some other additives, form a high-viscosity and high-performance mixed rubber.

Silicone rubber has excellent heat resistance, cold resistance, dielectric properties, ozone resistance and atmospheric aging resistance. The outstanding performance of silicone rubber is its wide operating temperature, which can be used in -60°C (or lower temperature) to +250°C. ℃ (or higher temperature) for long-term use. As for which property (quality) is superior, it is determined by the types of raw rubber, fillers and additives used.