Views: 19 Author: Site Editor Publish Time: 2021-03-08 Origin: Site
Supercritical co2 assisted tandem line is made for both grafting process and foaming. This line consists of mixer, loader, loss-in-weight feeder, twin screw extruder, single screw extruder, CO2 gas feeder, screen changer, water cooling strand pelletizing, melt pump, and static mixer.
(1) Grafting process
The first barrel is fed with PP powder by one loss-in-weight feeder and PP powder + maleic anhydride + adjuvant blends by another loss-in-weight feeder, and the other barrelss are respectively fed with liquid initiator and CO2 to assist the chemical reaction, and the liquid feeding port is reserved. The barrel near the end of processing section is equipped with a vacuum vent to discharge CO2 and unreacted monomers. The granulating auxiliary machine is a water-cooled strand granulating system.
By a loss-in-weight feeder, the first barrel is fed with special PP foaming materials. At the end of the processing section of the twin screw extruder, CO2 is fed, and after mixing, the materials are sent to the single screw extruder through a melt pump and then for foaming extrusion and finally for granulation.