METHOD FOR PURGING POLYETHYLENE TEREPHTHALATE FROM AN EXTRUSION BLOW MOLDING APPARATUS

摘要

A method for purging a molten thermoplastic material from a blow molding system. The method includes the steps of feeding the molten thermoplastic material into a flow head operably connected to a purge diverter valve including a channel and a closing member; opening the closing member, wherein the opening step diverts the thermoplastic material from the flow head into the channel and causes the thermoplastic material to flow through the channel; and collecting the thermoplastic material flowing through the channel. The method can be used to purge molten thermoplastic materials such as polyethylene terephthalate especially from an upward extruding blow mold system.