PVC obtained from polymerization processes is unmodified PVC. Before these PVCs can be used to produce end products, they need to be mixed with additives such as heat stabilizers, UV absorbers, lubricating agents, plasticizers, processing, hardening agent, impact resistance, filler, flame retardant agent, baking powder, etc.
In industry, the K value and the viscosity index are used to characterize the molecular weight and thus the intended use.
– K= 66-68 can be used to process hard products such as water pipes, oil pipes, rigid plates and profiles.
– Products with K= 65-71 are used for flexible products such as flexible sheets, floors, wallpaper, electrical cable covers, hose pipes, and medical instruments.
– Low K-value PVC (55-60) is used for injection molded products of pipes, fittings, electrical plugs, blow molding of bottles and other containers.