脱模剂是一种介于模具和成品之间的功能性物质。按脱模剂的化学成分可分为无机物、有机物和高聚物三类。脱模剂有耐化学性，在与不同树脂的化学成份（特别是苯乙烯和胺类）接触时不被溶解。脱模剂还具有耐热及应力性能，不易分解或磨损；脱模剂粘合到模具上而不转移到被加工的制件上，不妨碍喷漆或其他二次加工操作。脱模剂的作用是陡已固化的复合材料制品只能顺利地从模具上分离开来，从而得到光滑平整的制品，并保证模具多次使用的物质。由于注塑、挤出、压延、模压、层压等工艺的迅速发展，脱模剂的用量也大幅度地提高。
Release agent is a functional material between mold and finished product. According to the chemical composition of release agent, it can be divided into three categories: inorganic, organic and polymer. The release agent is chemical resistant and does not dissolve in contact with the chemical composition of different resins, especially styrene and amine. The demoulding agent also has heat-resistant and stress properties, not easy to decompose or wear; the demoulding agent is glued to the mold without transferring to the processed piece, and does not interfere with the spray paint or other two processing operations. The role of demoulding agent is that the steeply solidified composite products can only be separated from the mold successfully, thus getting smooth and smooth products and ensuring the multiple use of the material. Due to the rapid development of injection molding, extrusion, calendering, molding, laminating and so on, the dosage of release agent has also been greatly improved.