This publication, part of a series on multidimensional control of extrusion lines, illustrates a method using a roller head line to control two classes of dimensions: thickness dimensions relative to their corresponding die dimensions; and width dimensions, by manipulating the screw, roller and line speeds.
With roller heads, rubber is extruded directly on to a roller, which forms the lower moving surface of the die and facilitates flow through the die. The adherence of rubber to the roller means that the extrudate cannot swell while on the roller; the extrudate has the same width as the die opening at the location it detaches from the roller.