Acrylic glass lasers: how does that work?

Acrylic glass is very easy to work. With the advances of digital technologies, another processing technique is gaining in importance: the lasering of acrylic glass. Afterwards you will learn the peculiarities of lasering acrylic glass.

These products are acrylic glass (PMMA)

The technical name of acrylic glass is polymethyl methacrylate, PMMA for short. It is a thermoplastic (also plastomers). This is the most important prerequisite for being able to laser cut acrylic so well. Acrylic glass is also known as Plexiglas, with Plexiglas actually being the brand name for acrylic glass from Evonik Röhm GmbH. In addition to "Plexiglas" there are other brand names for acrylic glass:

  • Altuglas
  • Acrylite®
  • Friacryl
  • Limacryl
  • Piacryl
  • acrylic glass
  • Perspex
  • Vitrofelx

Which acrylic glass is better suited for lasering

From the former GDR, the name "O-Glas" has been able to save itself in the present. "O-glass" stands for "organic glass". Behind all the above-mentioned brand names is ultimately acrylic glass, which consequently can be lasered accordingly. However, there are quite subtle differences in the properties of acrylic glass. In particular, the manufacturing techniques affect the later quality of lasers. Cast acrylic can be lasered with significantly better cutting results than rolled (extruded) PMMA.

Usual technology for lasering

But it is not only the manufacturing technology that determines the quality of the laser-cut acrylic glass, which you can either cut or engrave with a laser. Also, the strength of the acrylic is a crucial factor, which in turn depends on the performance of the laser used. High-quality lasers are so-called CO2 lasers, which are also water-cooled. But not only in the strength of the material, laser cutting is limited. The laser result also changes with increasing strength of the acrylic glass.

Material properties during lasing

Due to the heat development, the cutting edge still looks straight at a material thickness of up to approx. 20 mm. In addition, it is increasingly conical to the outside. If you need extra strong acrylic glass products to be lasered, it is recommended that you carry out such a project in several steps, ie cut several thin PMMA sheets. Subsequently, the lasered acrylic sheets are glued. The gluing can be done in such a way that none of it is recognizable.

Acrylic glass edges clear again after lasering

A clear advantage also results from the lasering of acrylic glass. While other plastics produce a burr that needs to be flame-polished, acrylic glass does not require post-processing at any time. Also, the acrylic glass does not have to be polished at any time. However, the heat penetrates slightly into the acrylic glass during lasering - depending on the laser cutter used and the processed material, this is up to 2 mm.

Avoid stress cracks due to tempering

It is precisely in this area that stress cracks can arise. Although these are then easily visible even with translucent acrylic glass. However, the stress cracks are extremely noticeable if you want to paint the acrylic glass, because now the paint can tear. But you can also prevent this by tempering the acrylic glass with a laser immediately after cutting.

Tips & Tricks

During tempering, the acrylic glass is heated evenly to a temperature of 80 to 90 degrees, in order to then cool it very slowly back down to normal temperatures. Although this can be quite a home improvement make yourself (building a suitable box for annealing with a heater.However, the heating and the subsequent cooling must be done slowly and in the right amount of time, which requires a lot of experience for acrylic glass annealing.

Video Board: Skillbuilder: Seven Tips for Working With Acrylic