PVC lubricants commonly used in the seven species

PVC lubricant is usually tasteless , odorless , non-toxic light yellow waxy solid or flake . Physical indicators: PVC lubricants in the plastics industry is mainly used as mold release agents , plasticizers , antistatic agents , especially for plastic foam products, anti-shrinkage agents. In the production of PVC products as lubricants , and alkyd resin can be used as a modifier , a plasticizer of cellulose nitrate . PVC lubricants commonly used in seven types : calcium ( 1 ) stearic acid : white aluminium stearate  powder , melting point 148-155 ℃, non-toxic, have excellent lubricity and machining , non- sulfide pollution , and basic lead salts and lead soap and use, can increase the rate of gelation , the dosage is generally 0.1-0.4PHR. ( 2 ) white or yellow oxidized polyethylene wax powder or granules , containing a small amount of the oxidized polyethylene wax, a polar group , although still not compatible with PVC, but the higher the efficiency of the lubrication can be improved lubricity between the polymer and the metal improve extrusion efficiency , improve the dispersibility of the colorant , giving the product a good transparency and gloss. The amount of 0.1-0.5PHR. ( 3 ) stearic white or slightly yellow granules , mp 70-71 ℃. Slow evaporation at 90-100 ℃, as external lubricant in PVC processing hardware , the amount is usually 0.2-0.5PHR, and have the effect of preventing scale chromatography , but easy to use excessive blooming . ( 4 ) glyceryl stearate powder substance , melting at 85-87 ℃, has excellent heat resistance and flowability , increase the amount of filler , may contribute to the plasticizing . And waxes and use, to improve the thermal stability of PVC-U . General amount of 0.2-0.6PHR. In  Chrolinated polyethylene practice it was found that when two or more with the use of the lubricant , when used alone with the emergence of a different effect . In profile formulations, they use complex methods ( 5 ) wax melting point 57-63 ℃, no polar group , is a typical external lubricant . Because of its low melting point, easy to evaporate , a small melt viscosity , only within a narrow range from lubrication, suitable for single , twin-screw extruder , the general amount of 0.1-0.8PHR. This product is poor transparency , easy to whiten.
( 6 ) polyethylene wax white powder, a softening point of about 100-117 ℃, due to its relatively large molecular Chlorinated paraffin  weight , high melting point , low volatility and therefore at a higher temperature and shear rate , also showed significant lubricating effect. For hard PVC single , twin-screw extruder , the usual dose is 0.1-0.5PHR.