脱模原理
Demoulding principle
聚氨酯和模具表面的粘结力一般认为由两方面的原因所致。首先,模具的表面通常会被一层很薄甚至是单分子层的水膜所覆盖,这层极薄的水膜与异氰酸酯反应后产生强力的粘合性,其次,粘合是由模具内表层的极性基团与聚氨酯和聚脉的极性基团起反应而产生的化学键所致。为了使制品很好脱模,必须使模具表面有一致密的光滑薄膜) 要求该薄膜既不与原料反应又对模具有一定的粘附力, 同时有一定的柔韧性。把有效脱模物质（一般为惰性物质）通过介质（水）均匀地喷洒在模具上,待介质（水）挥发后便形成一光滑薄膜,从而起到脱模效果。
The adhesive force on the surface of the polyurethane and the mold is generally attributed to two reasons. First of all, the surface of the mould is usually a thin layer or even covered with water film single molecular layer, water film and the thin layer after the reaction of isocyanate adhesive, the adhesive strength is second, polar groups by the mold surface polar groups and polyurethane and poly pulse counter should be the chemical bond caused by. In order to make the products well demoulding, there must be a dense thin film on the surface of the mold. It is required that the film will not react with the raw material, but also have certain adhesion to the mold, and at the same time, it has certain flexibility. The effective demoulding material (usually inert substance) is uniformly sprayed on the mould through the medium (water). After the evaporation of the medium (water), a smooth film is formed, thereby playing a demoulding effect.