What are the benefits and advantages when comparing Cast acrylic and Extruded acrylic?

Before describing the benefits or advantages when comparing Extruded and Cast Acrylic sheet, it is important to understand the manufacturing process for each sheet product. Cast sheet is manufactured using a process known as the cell cast process, while Extruded sheet is manufactured using a process known as continuous manufacturing.

The cell cast process manufactures individual sheets of acrylic. Essentially, liquid monomer (unreacted acrylic) is poured between two panes of glass separated by a gasket to control the thickness of the sheet. For each sheet made, a gasket glass cell must be assembled. The cells are stacked on a vertical rack and put into an autoclave (a pressurized steam oven) for a given amount of time, based on the thickness, for reaction and curing. When the reaction has completed, the two panes of glass are separated from the acrylic sheet, and the sheet is inspected for optical clarity and proper thickness. The sheets are then masked for protection and packaged for shipment. Because a cell must be assembled and separated for the production of each sheet, the cell casting process tends to be very labor intensive.

Extruded acrylic sheet is continuously manufactured using an extrusion process. Because an extrusion-based process is used to manufacture the sheet, extrusion-grade polymers are employed, which have a lower molecular weight than the polymer produced in the cell cast process.

Cast sheet has the following benefits over extruded sheet:

• less low angle distortion
• low minimum run/order quantities
• thousands of standard and custom colors available
• greater range of available thicknesses (available in thicknesses greater than 1.00")
• slightly better chemical resistance
• less tendency to melt or chip during machining
• slightly higher service temperature
• more suitable for use involving continuous contact with water
• better capability to handle long-term mechanical loads

Extruded sheet has the following benefits over cast sheet:

• lower cost
• better thickness tolerance
• less dirt, lint, or particulate contamination in the sheet
• cements and thermoforms faster