laser marking processes:
Laser marking uses the highly concentrated energy from a very parallel beam of light, focused to a microscopic spot, which is moved over the marking area to create a variety of images on a wide range of materials – very much like writing with a pen on paper.
The legibility of marks made by lasers is achieved through a colour contrast between the mark and the base material. This contrast is a function of one of several processes including; engraving, thermo-chemical reaction, annealing and ablation:
Marks on anodised, plated or painted products are made by the laser removing the top layer to expose a base material in a contrasting colour.
Removing an opaque layer from a translucent substrate creates graphics for back-lit products and light show projection devices.
A colour change can be achieved in most bright steels by annealing. Through precise control over the heat input the laser produces a highly legible, dark mark on the surface but no material is removed.
Most plastics react when exposed to laser radiation. The resulting mark depends on the type of reaction – typically melting, foaming and bleaching - which is a function of the composition and colour of the base material. Additives may be used to enhance the colour change or produce a change to a specific colour.
Vaporising material produces a mark which is visible through the shadows and reflections of ambient light from the different angles carved into the surface.
advantages of laser marking:
Indelible:
Permanently modifies surface composition of material
Fast:
Marking at up to 1000 characters per second
Clean and safe:
No inks, acids or solvents
Wide range of materials:
Metals, plastics, rubber, etc.
Flexible:
Text, graphics, logos, bar codes, etc.
User-friendly:
Software driven
No tooling to wear:
No direct physical contact with the work piece
Cost effective:
Virtually no consumables
