In most polyurethane casting products such as rubber rollers, solid wheels, couplings, ceramic molds, liners, sieve plates, etc., the adhesion of casting polyurethane and metal is involved. Therefore, the problem of adhesion between casting polyurethane and metal must be solved in production. When bonding between casting polyurethane and metal, if the metal surface is treated properly and the selected adhesive is suitable, excellent bonding strength can be obtained. At present, the types of polyurethane elastomers and metal transition adhesives (primers) available are: NA-1 polyurethane adhesive; Chemlock218, 213, 219, Conap1146, 1146C; Thixon422, 423, 403, 404 (Rohm and Haas Company in the United States) and Cilbond48C, 49.

  In order to obtain the ideal bonding strength, in addition to choosing a good adhesive, the entire bonding process must be carefully operated. First, the metal is roughened with sandpaper or sandblasted (shot) to make the surface rough. The purpose is to expand the bonding area and activate the surface. Then deesterify in trichloroethylene or toluene deesterification tank (the effect of deesterification is better in trichloroethylene evaporation and deesterification tank) and dry. Then follow the standard rubber-to-metal bonding procedure or the method recommended by the adhesive manufacturer. Use a brush to coat or spray a certain thickness of adhesive, leave it to dry, and let the solvent fully evaporate. After the metal is preheated, pour the polyurethane compound