The proper application of lubricant is one of the keys to the success of the stabilization system. Therefore, it is particularly important to master its addition principle.
Paraffin wax, polyethylene wax, oxidized polyethylene wax, stearic acid and calcium stearate are commonly used lubricants in the extrusion process of plastic profiles. The following are the addition principles of these lubricants in different stabilization systems:
Organotin system: organotin stabilizer has no lubricating effect and poor dispersion. Therefore, when using organotin stabilizer, the lubricating system composed of paraffin, calcium stearate and a small amount of polyethylene wax should be appropriately increased, which can provide sufficient internal and external lubrication balance required for processing without pollution and toxicity.
Lead salt system
Due to the external lubricity of some lead salts, when polyethylene wax or oxidized polyethylene wax is used as external lubrication in the lead salt stabilization system, the dosage should not be too much, generally {{0}}.01 0.05 phr. If other additives in the formula have no lubrication effect, the dosage can be appropriately increased, generally 0.1 0.5 phr.
Rare earth system
Because the rare earth itself does not have lubrication performance, the rare earth stabilizers produced by general manufacturers are equipped with different varieties of lubricants according to the shear performance of the extruder. When using rare earth stabilizer, it should be selected according to the shear performance of extruder. Or during trial production, polyethylene wax and calcium stearate are used to make up for the lack of internal or external sliding in the stabilizer according to the profile forming conditions, so as to balance the processing needs.
