How to choose polyethylene wax in masterbatch formulation?

Polyethylene wax plays a role of lubrication and dispersion in the masterbatch system, increasing the compatibility of pigments with resins such as polyethylene, polyvinyl   chloride, and polypropylene etc. It is helpful to improve extrusion efficiency of   masterbatch and increase product surface gloss and processing performance.

The choice of polyethylene wax in the masterbatch formula needs to consider both   the pigment and the carrier resin in the masterbatch, and also consider the resin to be colored. According to the similar compatibility principle, homopolyethylene wax is   suitablefornonpolar plastics, such as polyethylene and polypropylene, while molecules of copolymerized polyethylene wax are connected with polar groups to introduce   carboxyl groups, and then esterified modification etc., so it is suitable for polar   polyvinyl chloride, polystyrene, ABS, and engineering plastics. The selected   polyethylene wax can only be mixed and dispersed with each other when they have   good compatibility with the carrier resin. In the same way, the selection of   polyethylene wax is also suitable for polarity matching of various pigments.

Polyethylene wax has wetting and dispersing functions in masterbatch processing. The viscosity of an ideal wetting and dispersing agent in its wetting stage of pigment particles (relatively low temperature) is relatively low, and it is helpful to the wetting of pigment particles. The viscosity in the shear dispersion stage (relatively high   temperature) is expected to be higher, so that its help for shear dispersion will be   more obvious. However, if the viscosity is too low, it is not helpful to disperse when   the shear force is the main for pigment dispersion。

In conventional processing, increasing the temperature of the dispersion system is   helpful for the wetting and penetration of pigment particles. Reducing the temperature is more helpful for the shear dispersion. How to find the processing conditions and   methods of effective disperse is what we must seriously consider and treat, so we   need to consider comprehensively and systematically and select the appropriate   polyethylene wax.

Polyethylene wax selection needs to consider the environment and product safety etc. Wax products with too low molecular weight will improve volatility and cause   environmental pollution and product odor etc. If such wax is used in some   sensitive applications such as food packaging materials, children's toys etc., it will   cause very serious adverse consequences. So its selection must be cautious.

Choose different kinds of polyethylene waxes from the end customer. If   masterbatches are used for lowend applications such as garbage bags, trash cans,   mulch films etc., customers can choose byproduct wax or cracking wax. If   masterbatches are used in midrange applications and have dispersion and taste   requirements, customers can choose synthetic polyethylene waxes. If the   masterbatch is used for special applications, where taste and heat resistance are   critical, then choose ZieglerNatta or metallocene polymerized polyethylene wax. At   this time, the choice of polyethylene wax is not only a kind of dispersant, but also   other requirements from the end application.