Coextrusion Innovation - Plastic Extrusion Tech Learn about coextrusion, the process of pushing two or more materials through a die to create a single piece of plastic. Call Plastic Extrusions today.Vinyl Fence: The Mono-extrusion vs. Co-extrusion debate May 15, 2017. It is then cooled, usually through water, and then cut to length. When vinyl fences first started to be extruded, they were all mono extruded,.Co-extrusion products | Spiratex Spiratex provides co-extrusion helps to combine much-needed properties from two materials into one application. Visit us to know more details!