Laser marking and engraving plastics

"It is possible to permanently engrave almost any type of plastic, although the various raw materials, color pigments and additives (e.g. fillers, additives, flame retardants) react very differently.
For laser marking plastics, the fiber laser offers you a range of different methods, such as dyeing, carbonation or foaming. Since various plastics react very differently, you should always test a material sample."

Here are some applications:

• Housings made of plastic
• Electric plugs

• Electronic components
• Printed circuit boards (PCB)
• Automotive parts
• Keyboards
• Tools and handles of tools
• Buttons and switches with day & night design
• Identification tags for animals
• Packaging
• Films
• Sensors

Many plastics can be marked with the conventional fiber laser. Most of the time, the marking result is very good, but for some plastics, the same level of homogeneity cannot always be achieved. These types of plastics can then be marked with a MOPA laser, which results in much more contrast and homogeneity. The adjustable pulse durations, which allow either short or long pulses, also help.

With dark plastics (such as PA 66 GF, PA 6 GF, PP GF, etc.), the surrounding material is less heated thanks to the short pulses and the associated low pulse energy. The plastics foam less and the marking is more homogeneous. Other plastics require more energy to heat up the material sufficiently. In this case, the long pulses help to optimize the foaming of the material. In both cases, marking with the MOPA laser leads to a more clear contrast and therefore to better (machine) readability. 

Foaming

Foaming leaves a tangible mark on the material. It can be seen as laser-induced boiling, which melts the surface. Due to the rapid cooling, bubbles are encapsulated in the material. These bubbles leave a positive mark, which is tangible.
The laser works on a low power level and longer pulses. Foaming works on all polymers, but also on some metals. Depending on the material the mark is light or dark.

Carbonizing

Carbonizing enables strong contrasts on bright surfaces. During the carbonizing process the laser heats up the surface of the material (minimum 100° C) and oxygen, hydrogen or a combination of both gases is emitted. What's left is a darkened area with higher carbon concentration.
The laser works with lower energy, which leads to slightly longer marking times compared to other processes. Carbonizing can be used for polymers or bio-polymers such as wood or leather. Since carbonizing always leads to dark marks, the contrast on dark materials will be rather minimal.

Color change

Color change on the material guarantees highest legibility. Laser marking with color change is basically an electrical process, which reorders the macromolecules (by changing the direction). No material is removed, but partial foaming is possible.
The laser works with a maximum pulse rate but low energy per pulse. Otherwise material would be removed or foaming might occur. Color change works on all polymers and the change of color can be bright or dark. Most color changes are dark.

Removing

Removing is used with multilayer plastics (laminates). During the removal process the laser beam removes the top layers, which had been applied to the base material. This results in color contrasts due to color differences in the layers.