Silicone tip and silicone washer

O-ring is a small cross-section of circular ring sealing element, commonly used cross-section is circular. The main material is synthetic rubber, which is the most commonly used seal in hydraulic engineering. It is mainly used for static sealing and sliding sealing. Compared with other seals, it has the following characteristics: a. Good sealing and long life. b. A single circle can play a sealing role in both directions. c. Good adaptability to oil, temperature and pressure. d. Small dynamic friction resistance e. small size, light weight, low cost f. Simple structure of the sealing part g. h. The size and groove have been standardized, the selection and procurement is convenient. The disadvantage is that when the dynamic seal is started, the friction resistance is larger, about 3-4 times the dynamic friction force, and it is easy to be squeezed into the gap under high pressure.

1. According to the relative motion of the seal and the sealed device can be divided into: static seal, reciprocating seal, rotary seal and switch seal.

2. According to the O-ring in the rectangular groove compression sealing with the amount of compression (tightness > can be divided into: compression, sleeve tightness, hydraulic, pneumatic and rotation of the five basic sealing fit, as well as in the end chamfer slot squeeze tight seal fit. In addition, there are two special sealing methods: sliding seal and floating seal.

3. According to the structure of the sealed parts can be divided into: end seal is axial seal, Angle seal (hole end face chamfered groove seal, shaft end face chamfered groove seal), cylindrical seal is radial seal (cylindrical inner diameter seal (piston rod seal), cylindrical outer diameter seal (piston seal)), cone seal and spherical seal.

1. Production mode

Silicone & nitrile are moulded

PVC&TPE adopts injection molding method

2. Chemical properties:

Silicone:

Silica gel is a thermosetting elastomer, insoluble in water, and does not react with other substances except strong alkali and hydrofluoric acid

Silica gel has excellent friction and temperature resistance, will not melt after vulcanization, and is not resistant to ozone. 

Nitrile:

Good oil resistance and aging resistance, it can be used in 120℃ air or 150℃ oil for a long time. In addition, it also has water resistance, air tightness and excellent bonding properties.

Its disadvantages are poor low temperature resistance, ozone resistance, and slightly lower elasticity. 

PVC:

High friction resistance to chemicals, corrosion resistance but not ozone resistance. In strong acids such as concentrated sulfuric acid, concentrated nitric acid will corrode, can not contact with aromatic hydrocarbons and chlorinated hydrocarbon substances.

Temperature resistance -15℃-80℃, poor light and thermal stability, not environmentally friendly

TPE:

High temperature resistance, corrosion resistance, ozone resistance, ozone aging (38℃)100 hours performance reduced by less than 10%, resistance to general chemicals (water, acid, alkali, alcohol solvents), can be soaked in solvent or oil for a short time; Environmental protection 

3. Process extension

Silica gel: common black and white, can be colored, can be processed

Nitrile: common black and white, can not do color, the outer surface can be electroplated colored

PVC: transparent color, can be done color, solid color semi-transparent color can be

TPE: transparent color, can be done color, solid color semi-transparent color can be, can be processed

Among them, nitrile can only make a matte surface, and electroplating can make the surface reach a smooth surface;

PVC is harder than the other three;