Calcium stearate is utilized as a warmth stabilizer for PVC as well as a lubricating substance and mold release agent for different plastics handling. When utilized as a PVC lube, it is generally considered an internal lubricant. Calcium stearate is the stearate of medium and also solid alkali calcium, which has strong polarity. The chemically energetic factor of PVC resin fragments can develop a relatively steady complicated system with calcium stearate. Both long-chain alkyl groups of calcium stearate have little compatibility with polar resins such as PVC, as well as create a local microscopic two-phase user interface inside the PVC material, that is, a lubricating film. The microscopic significance of its lubricating effect is that the force between the local lubricating interface formed by the non-polar long-chain alkyl team as well as the polar material sector is smaller sized than that between the resin sectors, and also due to the fact that there are numerous little pores between the material sectors, As a result, when the material segment is displaced, the randomly deformable alkyl team is pressed right into various other adjacent pores, therefore reducing the resistance of the resin sector throughout displacement and also functioning as internal lubrication.
In sensible application, calcium stearate as a PVC lube does not just play an internal lubricating role, its lubricating role is much more complicated, and in various other instances where the percentage of internal lubrication is fairly high, it will mirror the function of external lubrication. Additionally, it has a synergistic impact with several lubricating substances.
Making use of calcium stearate alone in the formula can speed up plasticization, rise melt thickness, boost torque, as well as have a certain demoulding impact, while making use of paraffin alone can delay plasticization, reduce torque, and have no demoulding effect. When calcium stearate and also paraffin wax (polyethylene wax) are mixed in a particular percentage, it reveals a great impact, and the torque value of the material can be greatly decreased. This is due to the fact that the paraffin penetrates right into the molecules of calcium stearate as well as strengthens the lubricating effect., showing a strong synergistic effect, transforming the diffusion of lubes.