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Selection and formula of PVC raw materials
1.In the production of resins with low polymerization degree of SG-5 resin, hard pipes should be selected.The higher the degree of polymerization, the better the physical and mechanical properties and heat resistance.However, the resin has poor fluidity and processing brings certain difficulties, so the generally selected viscosity is (1.7~1.8)×10-3 pa•s SG-5 resin is preferable.
2.Hard pipes generally use lead stabilizers, which have good thermal stability, and ternary lead is commonly used, but its own lubricity is poor.Usually lead and barium fertilizers with good lubricity.For hard tube processing, the choice and use of lubricants are very important. We should not only consider the interatomic forces of lubricating low molecules.
3.Decrease the melt viscosity is conducive to molding, and consider lubrication, prevent the melt from adhering to the molten iron, and make the surface of the product bright.
4.Internal lubrication is usually used for metal soap, external lubrication uses low melting point wax.
5.Mainly use calcium carbonate filler and barium (barite powder), calcium carbonate surface tube performance is good,However, too much dosage will affect the performance of the pipeline, and the pressure pipeline and corrosion resistance are the best. No or less fillers are used.
