Several Factors Affecting PVC Plasticization

1. Processing conditions:

Under normal processing conditions, the plasticizing rate of PVC resin increases with the increase of processing temperature and shear rate. The higher the processing temperature, the greater the temperature difference, and the faster the heat transfer rate. As PVC is a poor conductor of heat, the increase of shear speed will speed up the friction between materials to generate heat, speed up the contact frequency between materials and equipment, and improve the heat exchange efficiency

2. Resin structure:

The glass transition temperature and melting point of PVC increase with the increase of molecular weight and crystallinity, and the plasticization degree of PVC also becomes difficult.

3. Formula factors:

The use of lubricants, plasticizers, processing aids, impact modifiers, fillers, stabilizers, etc. in PVC processing has a great impact on the properties of PVC plasticization. Of course, different components have different effects on the plasticizing properties of PVC due to their different application purposes.

4. Mixing and processing process:

Mixing is the process of mixing and homogenizing PVC resin with heat stabilizer, modifier, lubricant, filler pigment and other additives. The equipment used is mainly high-speed kneader and cooling mixer. The mixing process relies on the mutual friction and shear force generated by the mechanical force on the materials to refine and heat the materials, melt some additives, and coat the PVC resin surface. PVC resin is refined under the action of shearing and friction, and its surface is soft and porous under the action of temperature. The additives are adsorbed on the surface and homogenized. The temperature further increases, the particle surface melts, and the particle density increases.