Theoretical basis of release agents
In theory, the release agent has a high tensile strength, making it less prone to polishing when in frequent contact with the molding resin. This is especially true when there is frosted mineral filler or glass fiber reinforcement in the resin. Release agents have chemical resistance and do not dissolve when in contact with the chemical components of different resins, especially styrene and amines. The release agent also has heat resistance and stress resistance, which is not easy to decompose or wear; The release agent is bonded to the mold without being transferred to the processed part, without hindering painting or other secondary processing operations. The specific working principle of the release agent is as follows:
1. The polar chemical bonds interact with the surface of the mold to form an adsorption type thin film with regenerative power;
2. The silicon oxygen bonds in polysiloxane can be regarded as weak dipoles (Si+- O -), and when the release agent spreads into a single oriented arrangement on the surface of the mold, the molecules adopt a unique extended chain configuration;
3. The free surface is covered by alkyl groups in a densely packed manner, and the demolding ability increases with the density of alkyl groups; But when the alkyl group occupies a large steric hindrance, the stretching configuration is limited, and the demolding ability will be reduced;
4. The molecular weight and viscosity of the release agent are also related to the release ability. When the molecular weight is small, the spreading ability is good, but the heat resistance is poor.