According to the relevant professionals to speak, wipe fender foam in the production process of the most commonly used foaming process are the following:
A step foaming process: raw material step polyether or polyester polyol (white material) and a polyisocyanate (black material), water, catalysts, surfactants, blowing agents, other additives and the like is added, with stirring at high speed foaming after mixing.
Second, the prepolymer method: prepolymer is a foaming process method (white material) and (black material) first made prepolymer, then adding water, catalysts, surface-active agents in the prepolymer, other additives, etc. In high speed stirring mixing foaming, after curing at a certain temperature curing can be.Third, the manual foaming method: that is, after all the ingredients accurately weighed, placed in a container and then immediately mixing these materials, foam injected into a mold or need space to fill. Note: Be sure to polyisocyanate (black material) is weighed into the final say.
Fourth, the semi-prepolymer method: is the part of polyether polyol (white material) and diisocyanate (black material) first prepolymer is made, then the other part of the polyether or polyester polyol and a diisocyanate, water, catalysts, surfactants, other additives and the like is added, with stirring at a high speed mixing foaming.