A laser is an artificial, bundled light source. Inscriptions are generated by means of color change or surface ablation by impact of the laser on the material.
The marking of materials with laser has been used in the industrial field for only two decades. The Weidling GmbH has been applying this method from the beginning on. As early as 1993, the first laser machine was installed. By now, the number of machines has risen to five altogether, covering different power classes. Besides the fabrication of security tags, primarily materials which are surface-coated or which have been aligned to or specifically produced for laser marking are marked with provided CAD-Data.
A laser (Light Amplification by Stimulated Emission of Radiation) is an artificial, bundled beam source. At the Weidling GmbH, two different types are used. A Nd:YAG laser for solids and a CO2 laser as a gas laser with several power classes, typically indicated in watt, allow the marking of many different surfaces and materials. Besides producing a surface marking, in which the result depends on the materials and its coating, a engraving is also possible. In the production of labels, specific two-layered foils are used, where the laser beam is not only able to remove the first layer (laser-beam removing), but also, with modified parameters, to cut out the contour of the label.
Laser markings are permanent, can only be destroyed by material loss and are water as well as smear resistant. The laser marking method was the first computer-operated procedure to allow the direct printing of various materials. Due to flexible data sources, this method is frequently used for numerations and other markings with variable data. Moreover, the attachment of machine-readable markings, such as barcodes or data matrix codes, is also possible. Data input can be carried out directly from a data base or a table.
In laser marking, as well as in other marking procedures, a distinction is made between the direct printing of material on the one hand and the fabrication of labels on the other. Materials used for the direct marking are primarily coated and uncoated metals as well as plastics, partly with special additives (laserbatch). In the fabrication of labels, mainly two-layered acrylate foils and specific engraving materials are used.
Laser marking ows its enormous success primarily to the heavy demand both from the automobile industry and mechanical engineering. But also in medical technology, where a high degree of traceability is required, laser marking represents a solution to many marking problems. The most frequent application is the type plate, followed by safety tags and direct markings. To sum up, it can be said that wherever a permanent marking without colour application is needed, the laser marking method represents an economical and flexible solution.