PVC resin melt viscosity increases, brittleness increases, impact strength decreases, heat The stability is reduced, which brings great difficulty to the extrusion processing of CPVC. At the same time, if the process is not controlled properly, a large amount of HCl gas will be produced, which will seriously corrode the processing equipment and molds. Therefore, the extrusion processing of CPVC resin has been discussed by people. Focus. In the processing of CPVC resin, “plasticization” is the key. Therefore, how to obtain good plasticizing quality from the formula, equipment and process technology is the key to CPVC resin processing.
CPVC resin is easier to decompose than PVC during processing, so it is necessary to add more heat stabilizer than PVC. During trial production, it can be added at 1.5 to 2.5 times the amount of PVC, and then according to the trial production The situation can be increased or decreased appropriately. The general principle is: heat stabilizer should not be added too much, otherwise it will affect the plasticization of CPVC resin.
Basically, all heat stabilizers used to process PVC can be used to process CPVC, such as lead salt stabilizers, calcium zinc stabilizers, and composite lead stabilizers. , metal soap stabilizers and liquid organotin stabilizers, etc. Among the many heat stabilizers, when pipes have different special requirements, there are differences in selection:
When producing sanitary CPVC pipes Non-toxic calcium zinc stabilizers or organotin stabilizers should be used;
When producing pipes that require temperature resistance, the use of liquid organotin stabilizers should be avoided as much as possible;
When producing high-impact pipes, calcium stearate is not added.
The following suppliers of calcium stearate will give you a brief introduction to the calcium stearate:
Calcium stearate is a white light crystalline powder. The melting point is 179~180℃, and it will decompose under high heat. Insoluble in water, cold ethanol and ether, soluble in hot benzene, toluene and turpentine, slightly soluble in hot ethanol and ether. Used as lubricant, sliding agent, heat stabilizer, release agent, accelerator, etc. in plastics, machinery, rubber, paint and ink and other industries.
Zinc stearate is a white powder that is insoluble in water. Mainly used as lubricant and release agent for styrene resin, phenolic resin and amino resin. At the same time, it also has the functions of vulcanization activator and softener in rubber. Can be used as heat stabilizer for PVC resin
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