Method for processing recycled polyethylene terephthalate bottles, uses multishaft extruders with screws rotating in same direction and specific ratios of housing and screw surfaces and screw diameter

摘要

Method for processing a product uses multishaft extruders with self-cleaning screws rotating in the same direction with a processing chamber which has a housing with internal surface Am and a free volume Vf. The extruder screws have an outer diameter Da and an inner diameter Di. Some or all of the processing zone has ratio Am3/Vf2 = 1020 - 3050 for two-screw extruders and 2000 -7300 for three-screw extruders, with a ratio Da/Di = 1.3 - 1.7. An Independent claim is included for a method for processing a product using multishaft extruders with self-cleaning screws rotating in the same direction with a processing chamber which has a screw surface Az and a free volume Vf. The extruder screws have an outer diameter Da and an inner diameter Di. Some or all of the processing zone has ratio Az3/Vf2 = 0.5 - 2.11 for two-screw extruders and 0.02 - 1.5 for three-screw extruders, with a ratio Da/Di = 1.3 - 1.7