Pad printing, or tampo printing, uses an indirect offset where ink is transferred from the cliché of a silicone rubber pad to the part intended for printing. Because of the pad’s elasticity and plasticity, it can also print curved surfaces. Pad printing is therefore ideal for printing text and images on plastic parts. The resolution is high in both monochrome and multicolour printing.
There are almost no limits when it comes to colour choices and effects. Printing inks are available as both single and two-component inks suitable for application on various materials for indoor or outdoor use. Colour choices are in principle unlimited and also defined under different colour and printing standards (e.g. RAL, NCS, PMS and CMYK).
AMB offers monochrome and multicolour printing and advice on the selection of the appropriate printing ink.
A laser beam comprises concentrated, high intensity light. Laser marking is also often incorrectly called laser etching. Etching is a chemical process in which a substance is dissolved by a corrosive, which is not at all how laser marking works.
Areas of application
There are many times in daily life when we read information or symbols that have been written on a surface by a laser, e.g. brands on plastic objects, most of the illuminated plastic buttons in your car as well as important product or security information on many different materials; the list of laser-marked surfaces can be as long as you like.
Laser marking includes a number of different processes where a material’s properties and requirements for the quality of the part determine the method used. Their common denominator is that when a (pulsed) laser beam hits a surface, the latter absorbs the laser energy and the material evaporates or is sublimed. In sublimation, a material passes directly from a solid to a gas without passing through the liquid phase.
All of the processes are eco-friendly as they do not add chemicals or materials.
Colour change in the plastic or lacquer
The laser heats the surface locally, which causes certain plastics to change colour on that spot. Some materials become lighter, others darker thus creating contrast and legibility.
We can also use additives in the plastic material for activation by the laser to assume a particular colour.
This method is often used for marking part numbers, service life or other important information that would otherwise be difficult to print.
Often used on metals or alloys. Removing the material creates a base relief that can also be accentuated using coloured oxides.
Ablation means removal of material from the surface. The method is often used to remove paint from a surface in specific places. This creates a contrast per se if the material is of a different colour. But the most common method is dark lacquered, partially transparent plastic with an LED behind it. This creates what is known as a day/night design, i.e. in darkness the ablated surface lights up but not the rest of the surface. Most illuminated buttons or controls in your car are made using this method.