Plastic laser engraving allows manufacturers to create all sorts of marks on their products. Although professional laser cutting focuses on shaping materials so that they can be made to very specific dimensions, engraving burns away a shallow amount of material so that maker's brands, serial numbers or part descriptions can be etched indelibly into plastics. How is this done and what do product designers need to consider when weighing up the merits of this industrial process?

Material Considerations

There are two types of plastic that are suitable for working with lasers. These are thermosetting plastics and thermoplastics. It is possible to carry out plastic laser cutting with both of these materials which are used in a wide variety of products. Although thermosetting plastics create strong internal bonds during the manufacturing process under heat, they are not suitable for either reheating or remoulding once the material has cooled down and hardened.

On the other hand, thermoplastics will become malleable when exposed to heat and the result is that they can be reprocessed and recycled because they strengthen once more as the temperature drops. As such, thermoplastics tend to be reprocessed using lasers more often than the thermosetting variety, but there is nothing to stop you using the latter material for laser engraving so long as it is freshly made.

Engraving Thermoplastics

For materials like PVC and acrylic, carbon dioxide laser cutters tend to be used for engraving purposes. This is because the materials can be etched with an incredibly fine amount of accuracy so long as the level of the engraving is not very deep. Indeed, such cutting equipment is deemed to be so reliable that it is sometimes used in surgical procedures.

An electric charge is produced by the system which, using a highly reflective mirrored surface, is mixed with CO2 turning it into a laser capable of engraving. Polycarbonates are particularly good when engraved with this sort of gas-based system because of the smooth finish that is afforded.

Micro-machining Considersations

Also used for engraving plastics, these laser cutters are ideal for micro-machining and making very small marks, such as discreetly hidden production dates and component numbers. A copper vapour laser engraver burns away plastic to leave an engraved area but can do so in tiny spaces that are no wider than a human hair. They also work incredibly quickly and can be connected to a computer to make them fully automated during a production run.

Contact a professional laser cutting service to learn more.