An extrusion device has a stack of at least two layers, the stack including an outlet, an inlet for a first material, and a feed channel for the first material arranged to fluidically connect to the inlet for the first material, the feed channel having a sloped end. A method of manufacturing an extrusion device includes forming an outlet, an inlet for a first material and a feed channel for the first material having a sloped end in a stack of layers, aligning the stack of layers to fluidically connect the feed channel for the first material with the inlet for the first material and to fluidically connect the inlet for the first material with the outlet, and bonding the layers together.

A method of manufacturing a lightweight, plastic shower door enclosure for enclosing a shower in a limited space environment includes providing a supply of a plastic polymer material for each part of the shower door enclosure to be manufactured, feeding the plastic polymer material to a rotating screw arranged within and along a central axis of a barrel feeder, controlling a rotation of the rotating screw to mix the plastic polymer material while compelling the mixed, plastic raw material forward through a heated portion of the barrel, ejecting the mixed, heated, plastic polymer material through an adapter and/or die as an extrudate supply for forming the each part and cutting the extrudate to the dimensions of the each part of the shower door enclosure.

The invention comprises a die apparatus including a flexible lip for adjusting a gap between the flexible lip and a second lip. The apparatus includes linear moving members that are moved through pivoting pivot members. The pivoting members pivot by adjusting a slide bar. The apparatus may also include a cross-bar contacting the lip and extending substantially the length of the lip, where the cross-bar is connected to the linear moving members that are moved through the pivoting pivot members. As a result, the dimensions of the gap may be changed by moving the slide bar in a first direction or a second direction.

An air ring has a main body including a plenum through which pressurized air enters the air ring, the main body including a generally circular interior that is unobstructed vertically above the main body. A generally circular forming-cone assembly is received in the generally circular interior of the main body, and includes at least one annular lip defining a passage through which pressurized air from the plenum exits the air ring for impingement upon the polymer tube. A plurality of fasteners secure the forming-cone assembly in the interior of the main body, the fasteners and forming-cone assembly being unobstructed vertically above the air ring, wherein the fasteners are accessible from vertically above the air ring and the forming-cone assembly is removable from the main body by vertical lifting without removal of other components from the air ring.