PVC performance PVC is an amorphous plastic with poor thermal stability and is susceptible to thermal decomposition. PVC is difficult to burn (good flame retardancy), high viscosity and poor fluidity. There are many kinds of PVC, which are classified into soft, semi-rigid and rigid PVC. The density is 1.1-1.3g/cm3 (heavier than water), the shrinkage rate is large (1.5-2.5%), and the surface gloss of PVC products is poor. A transparent hard PVC was developed to match the PC). PVC process characteristics Compared with the PVC processing temperature range (160-185 ° C), the processing is difficult, the process requirements are high, and it is generally not necessary to dry during processing (if it needs to be dried, it is carried out at 60-70 ° C). The mold temperature is low (20-40 ° C). When PVC is processed, it is easy to produce air grain, black grain, etc., and the processing temperature must be strictly controlled. The screw speed should be lower (50% or less), the residual amount should be less, and the back pressure should not be too high. Die exhaust is better. The residence time of PVC material in the high temperature barrel should not exceed 15 minutes. Compared with PVC, it is advisable to use large water products to enter the rubber. It is better to form and process under the conditions of “medium pressure, slow speed and low temperatureâ€. Compared with PVC products, the mold is easy to stick to the front mold. The mold opening speed (the first stage) should not be too fast. The nozzle is made into a pull-type type at the cold-flow point of the flow channel. The PVC material should be used in time before the shutdown of the PVC material (or PE). Material) Clean the barrel to prevent the decomposition of PVC to produce Hd↑, corrode the screw and the inner wall of the barrel.
Extrusion is a metal forming process , in which billet is passed through a die , to get required cross section of component .
Non cutting process
Production of Fixed cross section
Types of extrusion process
Direct extrusion process
Indirect extrusion process
Impact extrusion process
Hydrostatic extrusion process
Tube extrusion process
Extrusion Die Abutment,Nickel Based SuperAlloy Rene 88,Rene 88 Extrusion Die Abutment,Nickel Based SuperAlloy Shenyang New Industry Co.,LTD , https://www.topcobalt.com