Process selection of different polyurethane and metal bonding

  To make the product easier to remove from the mold, a release agent is required. Be extremely careful when using release agents. Generally, it is not recommended to use silicone oil. Avoid squeezing the release agent onto the bonding interface between the metal and the CPU elastomer during the pouring process to affect the bonding strength. When the CPU is poured on the metal, as the product vulcanizes, the bonding strength between the CPU elastomer and the metal also increases. When the product is just released from the mold, the bonding strength is still relatively low, so it must be handled carefully.

  As for the products that need to be bonded, some need to be compression molded, and some are not. For compression molded products, it is particularly important to grasp the timing of mold closing. Too early, there is easy to have bubbles in the product; too late, it is easy to crush the glue or cause the flash to be too thick, which is not conducive to bonding. Moreover, when the product is demolded, the mold temperature is higher, and the bonding strength is not high at this time. Therefore, for rubber rollers and rubber wheels, the temperature of the mold should be lowered before demolding to shrink the glue layer and then demolding. It is much easier and will not affect the bonding strength, but it will affect the production efficiency, which should be determined according to the specific situation. Compression molding vulcanization will increase the difficulty of demolding, so the normal pressure vulcanization molding process is generally used for products that are easy to machine such as rubber rollers and rubber wheels.