[Zinc stearate supply and procurement] Zinc stearate is widely used as a release agent

Release agent is used on the surfaces of two objects that are easy to adhere to each other. An interface coating that makes surfaces easy to release, smooth and clean.

Release agents are chemically resistant and will not dissolve when in contact with the chemical components of different resins (especially styrene and amines). The release agent also has heat and stress resistance and is not easy to decompose or wear; the release agent adheres to the mold without being transferred to the processed parts, and does not hinder painting or other secondary processing operations. Due to the rapid development of injection molding, extrusion, calendering, molding, lamination and other processes, the dosage of release agents has also increased significantly.

Release agents are widely used in metal die-casting, polyurethane foams and elastomers, fiberglass reinforced plastics, injection molded thermoplastics, vacuum foamed sheets and extrusions In various molding operations such as profiles. During molding, sometimes other plastic additives such as plasticizers will seep out onto the interface, and a surface remover is needed to remove it.

The choice of release agent should be determined based on the raw materials used for injection products. One of the more commonly used release agents is zinc stearate.

Zinc stearate is generally a white powder, insoluble in water, but soluble in hot ethanol, benzene, toluene, turpentine and other organic solvents; It decomposes into stearic acid and corresponding salts when encountering acid; it is fire hazard under dry conditions, with an auto-ignition point of 900°C; it is hygroscopic.

Since most liquid internal release agents are acidic, they can cause color changes when using acid-sensitive pigments or when using alkaline fillers. When used, such as calcium carbonate, acidic release agents will react with it, causing the viscosity of the mixture to increase. However, zinc stearate is an acidic filler activator. It is only more active for acidic fillers and has a lower price. When used as an internal release agent, its performance has always been stable.