Multi-layer extrusion technology is a process in which two or more polymers are extruded and simultaneously joined in a co-extrusion die head to form tubing with multiple layers. Running two or three extruders into a co-extrusion die head produces a single, multi-layered, extruded tube from a combination of materials with different physical properties, friction coefficients and bonding characteristics. In this article we will discuss multi-layer coextrusion of dissimilar and similar polymers.