2 or more extruders
• The extrudates from 2 extruders are merged and welded together to form a multilayer structure.
• PVDC/ adhesive/ nylon
• PP/ adhesive/ EVOH/ adhesive/ PP
• PET/ adhesive/ PP/ adhesive/ PVDC/ regrind PP/ PP
• Adhesive (a thin layer of adhesive resin, „Tie layer‟) is used to improve the adhesion between 2 different polymer layers.