How is acrylic glass made?

The basic chemical production of acrylic glass is complicated and not important to the user - apart from the properties that acrylic glass has. However, the further processing of the "raw material", from which acrylic glass is produced in the last steps, is of crucial importance in the choice of acrylic glass, which in individual cases must meet all the desired requirements.

Production process of acrylic glass

The production of the base product for acrylic glass is ensured by various polymerizations. Among others, the following polymerizations are suitable for this purpose:

  • Chain polymerization (anionic, free-radical)
  • Block polymerization (free-radical)
  • living polymerization (free-radical)
  • Emulsion or solution polymerization (free-radical)

Acrylic glass - a thermoplastic

From this production is derived from the term "polymers", which is used for plastics. Acrylic glass also carries this production process in its technical name: polymethyl methacrylate or PMMA for short. In particular, acrylic glass is also a so-called thermoplastic, ie plastics which, like acrylic glass, can be bent, shaped, rolled or even welded under certain thermal conditions.

Extruded or cast acrylic glass

But also the production of a certain end product made of acrylic glass can be derived from the raw material based on these properties. This is particularly evident in the world-famous brand acrylic glass from Evonik Röhm GmbH, namely Plexiglas. This is offered as Plexiglas GS or Plexiglas XT. Plexiglas GS is nothing more than cast acrylic, while the Plexiglas XT is extruded (rolled) Plexiglas.

Differences depending on the manufacturing process

The differences are more in the details. Poured acrylic glass is temperature resistant up to 80 degrees Celsius, extruded acrylic only up to 70 degrees. But these are not all differences. But you have to take a closer look at the manufacturing process, especially from rolled acrylic glass: acrylic granules are heated and then rolled out. As a result, the structural properties are completely different than with cast acrylic.

Advantages and disadvantages with regard to extruded / cast PMMA

However, depending on the application, the disadvantages that we list below may be exactly those properties that are needed:

  • cast acrylic has a higher quality surface
  • Rolled acrylic reacts to elevated temperatures with long service life with stress cracks
  • Rolled acrylic glass must not fall below certain minimum thicknesses
  • better suited for engraving and lasering of acrylic glass is cast PMMA
  • The bending and forming of acrylic glass is inferior in cast PMMA

Lasers and engraving

In the case of laser engraving of cast acrylic glass, the treated surface is white, with rolled acrylic glass it is dull gray, moreover a burr is produced. Although a cast acrylic component can not be flame-polished, but in contrast to the rolled PMMA, no burr is produced lapsed on the lasers.

Tips & Tricks

The price of acrylic glass shows a marked difference between rolled and cast PMMA. Often the cheaper, rolled acrylic glass is equated with a lower grade quality. But that's not easy to explain. It is the individual requirements that determine whether rolled or cast acrylic is to be used.

Differences in longevity in temperature

For boats and yachts, the components of which are like acrylic glass hatches, the difference in longevity is particularly serious: boats and yachts are often on the move in warmer regions (Mediterranean for example). At moorings in warmer regions, the longevity of cast acrylic is well above that of extruded acrylic, as there are rapid cracks.

Heat treatment (molding, bending) of acrylic glass

On the other hand, if you want to bend or shape colored acrylic glass (after heating), the rolled PMMA is more suitable because of its heterogeneous properties (cast acrylic is homogeneous). When cast acrylic glass, which is bent or deformed, the homogeneous structure must be abandoned. Therefore, colored acrylic that is cast may explicitly have slight color changes (in the bent or deformed area).

Video Board: Acrylic sheet process