Metal inserts must be carefully prepared in operations involving cleaning and roughening surfaces (grit-blasting or phosphatizing), stamping out parts, application of primer (usually by dipping), and curing of the primer (often by baking for a short time at moderate temperature).³ Primer curing minimizes the possibility of wiping primer off portions of the insert by stock flow during molding. The treated metal inserts must be used within a relatively short time (usually a day or less), so that functionality necessary for bonding is not lost by reaction with moisture in the air. Freshness of the primer surface is particularly important for peroxide-cured and base-resistant fluoroelastomer compounds. Compound formulation should be adjusted to attain good adhesion.

How to Choose the Right Oil Seal

All are fitted with a spring to preload the sealing lip. All these types are for non-pressurised or low-pressure applications up to 0.5 bar for diameters of a limited size. For diameter of 500 mm or more, the maximum pressure is 0.1 bar. For higher pressures, special types or PTFE lip seals can be used.