Sheet

Overview

Sheet extrusion transforms TP materials into roll or sheet stock through a combination of heat and pressure. The extruder plasticizes the plastic and pumps it through a die (Chapters 2–6) and it continues downstream in the sheet line. Figure 9.1 is a schematic of a sheet line and Figs. 9.2–9.4, 2.5, and 2.29 show examples of the type of equipment used in sheet lines. The terms sheet or sheeting normally describe a flat plastic product that is 0.25 mm (0.010 in) or greater in thickness. Some industries use 0.10 mm (0.004 in) as the dividing line between film and sheet. Widths can be up to at least 3 m (10 ft).