Method for incorporating processing additives in polyvinyl chloride resins and additive concentrate for use therein

摘要

Processing additives are incorporated in polyvinyl chloride resin by preparing an additive concentrate in free-flowing powder form and mixing an aliquot portion thereof with a batch of polyvinyl chloride powder in a high shear mixer to form a molding composition containing the additives in the desired proportions. The additive concentrate is made by preparing an aqueous emulsion of the lubricants and stabilizers which is then mixed with solid additives such as pigments and fillers to form the free-flowing additive concentrate powder. By using the additive concentrate the need for individual weighing of each additive to be added to each batch of polyvinyl chloride resin is avoided.