Application of polyethylene wax in plastic processing

The viscosity of polyethylene wax is much lower than that of plastic melt, and it can be used as a plastic melt index modifier. Because of its good thermal stability, low volatility at high temperature and good dispersibility, it can improve the fluidity of plastic processing, thereby Improve plastic processing properties.

The molecular structure of polyethylene wax is similar to that of polyolefin, the polarity is very weak, ac-6a polyethylene wax and the compatibility is large, and it plays an internal lubricating role in the processing of polyolefin plastics. The modified polyethylene wax has high polarity, low compatibility with polyolefins, and plays an external lubricating role. Polyethylene wax can significantly improve the flowability of the material in the extruder and the release of the finished product, while the finished product shows better surface properties, longer-term stability and more attractive color. Polyethylene wax is used as a lubricant in the PVC film, profile, pipe, and plastic processing industries, which can improve the toughness of plastic products, make the surface smooth and smooth, and improve the yield.

As a PVC lubricant, it not only needs to have the function of internal lubrication, but also needs to have compatibility. Compatibility with a variety of resins is the premise for PVC lubricants to function. Esterified polyethylene wax has better performance in compatibility and is compatible with poly It is compatible with amide, ABS resin, polyoxymethylene (POM) resin, etc. Esterified polyethylene wax has good compatibility with PVC, and has both internal and external lubricating and brightening effects. During calendering or molding, it can prevent sticking to the roller; during extrusion molding or injection molding, it can effectively prevent sticking to the screw, improve the demoulding effect, and make PVC products bright, beautiful, soft to the touch, and bright. , the carboxyl group and ester group on the molecule form complex or ionic chain chemical effect with filler and pigment, improve the combination between filler and matrix resin, and obtain high physical and mechanical properties.

Due to the presence of benzene rings in polystyrene, and the proportion is also large, compared with polyethylene, polystyrene has a larger polarity, has a certain degree of compatibility with internal and external lubricants, and has better formula elasticity. Some. Amidated polyethylene waxes are often used in polystyrene production as internal lubricants to improve mold release and can be added prior to the polymerization process.

Thermoset plastics require lubricants and mold release agents during production and processing. The use of compatible internal lubricants can improve flowability, while external lubricants can reduce material adhesion to hot machine parts, thereby improving mold release. Polyethylene Waxes combine with internal lubricants with a very strong mold release effect, providing greater operational tolerance.

In polyamide processing, polyethylene wax is used as a dispersant to make the reinforcement and pigments evenly distributed in the polyamide, while in polyamide injection molding, the ease of demolding depends on the degree of crystallinity and the effect of the lubricant .

Modified polyethylene wax is generally used as a lubricant. In the injection molding of linear polyester (PET), polyethylene wax plays an important role in improving the mold release and fluidity of filled PET. Thermoplastic polyurethane (TPU) Immediately after processing, it is very viscous, and the use of polyethylene wax can give it a very good mold release effect. New engineering plastics are very difficult to process. Some plastics are very viscous soon after processing, and some have very high molecular weights and therefore have extremely poor fluidity. In plastics, it has both internal and external lubrication and mold release functions, and has anti-migration properties. It is an extremely important processing aid.

The molding methods of wood-plastic composites (WPC) mainly include molding method and single-screw extrusion method. Polyethylene wax is usually used as a lubricant, which can prevent the reduction of the melt strength of the material and the scorch of the wood powder due to the long residence time in the barrel, improve the processing performance and improve the flow performance of the material. To a certain extent, the physical plasticization process is adjusted, and a boundary film is formed between the material and the metal, which can not only prevent the material from adhering to the metal wall, but also weaken the material’s effect on the processing equipment and molds Wear, prolong the oil life of the extrusion equipment, and also help to improve the appearance quality of the product.

Polyethylene wax is widely used, but there is still a lot of room for development in the application of PVC profiles, plastic pipe fittings, plastic molding processing and inks, coatings, floor waxes, automotive waxes, glazing waxes and other products, which still needs to be studied. and development to get more applications.