As PVC Resin has low heat stability, PVC stabilizer is added into PVC Resin to fix the defect of PVC chains and absorb HCL gas released by decomposition of polyvinyl chloride (PVC). Meanwhile PE Wax also needs to be added as lubricant due to high viscosity and big shearing index of PVC Resin.
Polyethylene Wax, namely PE Wax is a kind of low molecular weight polyethylene polymerized from ethylene directly. PE Waxes vary from molecular weight, distribution of molecular weight and molecular structure as per different polymerization method and catalyst system. The appearance of PE Wax is usually white powder, with the average molecular weight of 1500-5000 and melting point of 100-120oC. PE Wax has excellent external lubrication in PVC processing and it will contributes to improving fluidity, production, dispersion and demould properties. Thanks to its high molecular weight, high melting point and good thermal stability, it has strong lubrication under high temperature and high shearing circumstances.
Currently, PE Wax can be divided into following types in domestic market:-
1. PE Wax homopolymerized from ethylene. This type of PE Wax has good external lubrication, high gloss and good stability;
2. By-product in the process of ethylene polymerization. This type of PE Wax has low viscosity, high melting point and excellent external lubrication;
3.PE Wax cracked from low molecular weight polyethylene, generally called cracking wax. The cracking workmanship is simple.