Terminology knowledge in the rubber industry
1. Rubber refers to a substance that has the property (elasticity) of exerting a slight force to stretch and recover after removing external forces, and requires cross-linking reaction. There are natural rubber produced from latex collected from rubber trees, synthetic rubber chemically synthesized from petroleum, and recycled rubber. Rubber that does not require cross-linking and can be molded like plastic is called thermoplastic elastomer.
2. O-ring refers to a circular sealing element with an O-shaped cross-section. It is generally installed in the groove and moderately compressed, and can be used as a sealing element for various fluids such as oil, water, air, gas, etc. According to different usage methods, there are fixed use, sports use, etc.
3. The thin rubber that flows out from the gap of the mold assembly. The size of the trimming allowance for the O-ring is specified in JIS B2408.
4. Compression permanent deformation refers to the permanent deformation rate of rubber after being subjected to compression load for a long time. It must be noted that it cannot be confused with permanent deformation caused by low-temperature compression.
5. After removing the load that causes deformation, the material can restore its original shape properties. The property that cannot be restored is called plasticity.
6. Compression allowance O-ring is usually used for compression, so the depth of the installation groove can be set to be slightly smaller than the thickness of the O-ring. The compression amount is called "compression margin".
7. The so-called "parting line" refers to the texture of the mold's closing line.
8. The selected O-ring is not suitable for oil resistance, drug resistance, etc. The O-ring becomes soft and swollen due to liquid inhalation.
9. Hardening sometimes leaves unreacted vulcanizing agents in the rubber, which continue to be vulcanized by heating, resulting in an increase in hardness. This is called "hardening". However, when high temperatures persist for a long time or rise sharply, the rubber will harden sharply and lose its flexibility, causing molecular bonding to break and even crack, and even be damaged. (Depending on the type of rubber, it may sometimes cause molecular chain breakage and softening). Ozone cracking: Ozone is a highly oxidizing gas that, when exposed to it, promotes the cutting and crosslinking of rubber polymer chains, leading to rubber degradation (low molecular weight reduces strength, hardening reduces flexibility). After the deterioration continues to develop, a type of "crack" called "cracking" will appear on the surface.
contact：cathy@brightrubberplastic.com
