Guide for the selection of rubber seals
Several important indexes must be taken into account when selecting rubber materials for sealing parts:
First, the use of conditions
1 objects to be exposed (including liquids, gases, solids and chemicals)
2 temperature range (minimum and maximum temperature)
3 the consideration of the minimum compression ratio at the time of the seal under pressure
4 considerations for static or dynamic use
Two, design requirements considerations
1 consideration of combination
2 possible chemical reactions in use
3 service life considerations are likely to fail in the review
4 component lubrication and assembly methods
5 tolerance considerations
Three, inspection requirements considerations
1 define test standards
2 the demand for sample confirmation
3 setting acceptance criteria
4 main sealing surface settings
Four, the choice of material specification
1 determine the selection of material specifications, such as the United States ASTM, Germany DIN, Japan JIS... etc.
2 discussion with suppliers, to define the selection of plastic materials
3 selection of suppliers quality stability
Five, cost considerations
For the selection of materials, to avoid the high cost and does not match the practical knowledge of plastic material, resulting in the finished product can not play the sealing function, either natural or synthetic rubber has the characteristics of general rubber, such as elastic recovery after compression, flex resistance, resistance to compaction and permeability of gas liquid resistance. Each kind of rubber elastomer has his unique performance, at the same time by the composition of rubber formulation can also have an effect on its performance. At present there are more than twenty species of rubber elastomer, and is widely used in all kinds of material needs, at the same time through the professional mixed refinery formulation and mixing, can provide more in line with the needs of the engineering, the rubber vulcanization by hot plasticity mixture into thermosetting expectation shape, chain effect (Crosslink) to provide the molecular link strength and elastic rubber to seal performance, seal and so the designer to create and rubber suppliers discuss decided to use the material is very important.