In the PVC processing industry the use of lubricants is absolutely essential. Lubricants influence the manner in which PVC melts and flows during processing. Several parameters like energy consumption of the processing equipment, melt pressure in the machine, productivity, dispersion of fillers and pigments, gelation of the PVC, etc. are directly affected by the right selection, the best combination and the optimum dosage of lubricants. Jubang has been supplying lubricants to PVC processors for over 15 years. Unique products have been developed to meet the specific needs of this industry.
Polyethylene Wax, also known as PE Wax, is an ultra low molecular weight polyethylene consisting of ethylene monomer chains. PE wax has a large variety of uses and applications. PE Wax is available from on-purpose production and as a byproduct of polyethylene production. Polyethylene wax is recognized in the PVC industry as very efficient external lubricant. Wuxi Jubang as the China’s leading commercial manufacturer of low molecular weight polyolefin polymers offers a wide range of high quality PE Wax specifically designed to perfectly meet the various requirements of PVC processors.
Non-functional homopolymeric PE Wax is relatively incompatible with PVC. Due to their amorphous structure and low meltviscosity they act as strong external lubricant. During processing, these products move to the PVC melt – metal interface where a film layer is formed resulting in reduced shear and improved surface quality (gloss).
Low-density oxidized homopolymers
Oxidized LD-Polyethylene waxes contain functional groups (acid and ester groups) causing improved compatibility with the PVC melt. In the extrusion process these waxes provide efficient external lubrication that help to maintain premium physical and aesthetic properties under high shear operating conditions.
High-density oxidized homopolymers
Based on their high melt viscosity, crystalline structure and functional groups, oxidized HD-Polyethylene waxes act as very powerful fusion promoters. They improve metal release and distribution of other additives in rigid PVC extrusion. The increased melt homogeneity results in enhanced dimensional stability of the extruded product.
Lubricants have a strong effect on surface quality of the extrudate. While effective external lubrication creates smooth surface and high gloss, a more internal lubricant tends to matt the surface. By selecting the right combination of lubricants you can adjust the surface quality to a level of your choice.
Speed of fusion is affected directly by the character of the lubricant. Non oxidized LDPE waxes tend to delay fusion of the PVC melt; oxidized HDPE waxes act as strong fusion promoters. With a combination of the lubricants you can individually adjust the point of fusion to your compound formulation and extruder characteristics. In conjunction with fusion, the pressure profile in the extruder can be adjusted. Fusion accelerating lubricants cause higher melt pressure in the last section of the extruder.
Tin formulations are known for an extraordinary demand on external lubrication to avoid sticking at the metal surface. Oxidized HDPE waxes are recognized as superior additives for metal release.