1. Selection of resin
(1) Selection of Varieties of Plastic Particles
The selection of plastic particles should be based on the variety with the closest performance to the modification purpose. The advantage of doing so is that it can save the amount of additives added, reduce production costs, and reduce process flow.
The most common example is to obtain wear-resistant modified varieties, plastic particles (resins) should first consider selecting the three major wear-resistant resins PA, POM, and UHMWPE; and for transparent modification, the resin should first consider selecting the three major transparent resins PS, PMMA, and PC.
(2) Selection of resin flowability
The viscosity of various plasticizing materials in the formula should be close to ensure processing fluidity. For materials with significantly different viscosities, transition materials should be added to reduce the viscosity gradient.
(3) Plastics are divided into high fluidity plastics, low fluidity plastics, and non fluidity plastics
Specifically, as follows:
High fluidity plastics - PS, HIPS, ABS, PE, PP, PA, etc.
Low fluidity plastics - PC, MPPO, PPS, etc.
Non flowing plastics - polytetrafluoroethylene, UHMWPE, PPO, etc.
Different processing methods require different flowability, so grades are divided into injection molding grade, extrusion grade, blow molding grade, rolling grade, etc.
Different modification purposes require different fluidity, such as high filling requiring good fluidity.
(4) The selectivity of resin towards additives
If PPS cannot add lead and copper containing additives, and PC cannot use antimony trioxide, these can lead to depolymerization. Meanwhile, the acidity and alkalinity of the additives should be consistent with that of the resin, otherwise there will be a reaction between the two.
