The laser marking of plastics falls between the two main wavelengths of laser used in industry today (YAG and CO2). In this case, we have used Fibre laser marker as it is close to YAG wavelength.
The product is an identification plate, used for a sub-assembly for a well known earth movement vehicle manufacturer. The plate contains a combination of information for traceability as well as environmental instructions.
The fibre laser provides a positive result on the materials, although the process window is very small. Some variation across the mark can be seen. In some cases, where power levels are too high surface blistering can occur.
There are a number of differing changes to the material surface during laser marking, and it is very dependent on the material itself as to which one occurs.
- A thermochemical foaming, creating gas bubbles to the surface of the material, is the most common. The light scatters across the affected area producing the light marking that appears.
- Bleaching is another effect that is common. Here the pigment used to achieve the product colour is removed creating a visual difference.
- The third mechanism is vaporisation where the material is heated, very quickly, to the point where it vaporises, and is removed leaving behind the created image.
These three laser marking effects, can be enhanced by the adding of laser sensitive additives and can generate considerable advantages. The additive acts as an abortion barrier, boosting the ability of the laser to process better. In some materials, the laser marking ability would not be possible without this additive. In this example, we did not feel the additional cost to the component by adding additives, was worth the potential advances in the mark quality, and they were happy with the results achieved.
If you would like further information on this laser marking application, or any other application, please request a call back or talk to one of our laser marking specialists on 01737 826902.
