How PLEXIGLAS® is produced
There are two ways in which PLEXIGLAS® can be produced: Methyl methacrylate (MMA) is either poured between two glass sheets and cured, or it is extruded as polymerized MMA (PMMA). Both processes result in different PLEXIGLAS® products, that, nevertheless, share similar properties.
Casting: Production of PLEXIGLAS® GS sheets
The process by which PLEXIGLAS® GS solid sheets are produced is called casting. The liquid MMA monomer is pumped into a mold typically consisting of two glass plates held at a distance by a flexible gasket or spacer. The height of the spacer therefore largely determines the thickness of the sheet that is subsequently formed. The necessary volume of reaction solution is then filled into the chamber through openings in this spacer. During this process the chamber is held at an angle in a frame so that air bubbles may escape.
The polymerization proceeds in the chamber. This means that the liquid monomer is cured to form a solid sheet, either by a temperature-controlled process or a chemical, initiator-controlled process. After polymerization is complete, the glass plates and spacer are removed from the PLEXIGLAS® GS sheet. The sheets are then covered with masking film, cut to standard size, and stacked on pallets.
PLEXIGLAS® GS solid sheets with matt or textured surfaces are produced as described above, using appropriate glass plates.
Extrusion: Production of PLEXIGLAS® XT sheets
PLEXIGLAS® XT solid sheets are produced in an extrusion process. PLEXIGLAS® granules or molding compound are fused in a heated steel cylinder and pressed through a die by a screw conveyor rotating in the cylinder, somewhat similar to a meat grinder. The PLEXIGLAS® XT solid sheets obtain their final form and surface in subsequent calibration, generally in a multi-roll calender.
In multi-roll calenders the surface of the temperature-controlled rollers determines the sheet surface, and the roll gap at the exit defines the thickness of the plates or sheets. After calibration, the extruded PLEXIGLAS® XT solid sheets are covered with masking film, cut to size, and stacked on pallets.
Multi-skin and corrugated sheets as well as rods and tubes are produced by the extrusion process.
Where is PLEXIGLAS® produced?
PLEXIGLAS® products are produced at various sites worldwide and marketed in Europe, Asia, Africa, and Australia under the registered trademark PLEXIGLAS®. In the Americas the products are marketed under the brand name ACRYLITE®.