Today, Shandong Calcium Stearate manufacturer shares with everyone the application of calcium stearate in PVC formulations.

Calcium stearate serves as a heat stabilizer for PVC and a lubricant and release agent for various plastic processing. As a lubricant for PVC, it is generally considered an internal lubricant. Calcium stearate is a stearate salt of medium-strength alkali calcium with strong polarity, and its chemical active points on PVC resin particles can form a relatively stable coordination system with calcium stearate. However, the two long-chain alkyl groups of calcium stearate have low compatibility with polar resins such as PVC, forming local microscopic two-phase interfaces within the PVC resin, i.e., lubricating films.

The microscopic essence of its lubricating action lies in the interaction between the locally formed lubricating interface of non-polar long-chain alkyl groups and the polar resin chain segments, which is weaker than the interaction between the resin chain segments. Moreover, due to the presence of numerous small pores in the resin chain segments, when the resin chain segments shift, the alkyl groups, which can deform arbitrarily, are squeezed into adjacent pores, thereby reducing the resistance during the shift of the resin chain segments, and achieving internal lubrication.

In practical applications, calcium stearate, as a lubricant for PVC, does not solely serve an internal lubricating role. Its lubricating action is rather complex; under conditions where internal lubrication ratios are higher, it also exhibits external lubricating properties. Moreover, it has a synergistic effect with many other lubricants.

Utilizing calcium stearate individually accelerates plasticization, enhances melt viscosity, and offers certain demolding effects. In contrast, using paraffin alone exhibits delayed plasticization, reduces torque, and lacks demolding properties. When calcium stearate and paraffin (polyethylene wax) are mixed in a specific ratio, they yield excellent results. The material torque value can be significantly reduced due to the paraffin infiltrating between calcium stearate molecules, strengthening the lubricating effect and demonstrating a strong synergistic effect, altering the dispersal of the lubricant.