Rofin’s wide range of laser sources means that we can offer the ideal solution to any requirement when working with plastics, from CO2 for marking and cutting, to diode laser systems for plastic welding
Dependent on the type of laser used, several different types of mark may be applied to plastics.
In the simple Colour Change method, the laser energy alters the pigments in the material, so that its appearance changes. However the surface remains virtually unchanged and as the material is changed down to a depth of 200 µm, the marking is remarkably durable and abrasion-proof. Addition of laser-sensitive pigments can improve contour sharpness and contrast of the markings.
The Foaming Method (a partial degradation creating gas-bubbles within certain polymers) scatters the light and produces light marks.
CO2 lasers can achieve a similar mark to that of hot stamping, which only becomes visible by the shadow of the engraving. This effect which is desirable for applications such as marking of audio and data discs.
In general a CO2 laser produces a clean, crack free cut of the highest quality, especially compared to common separating methods, such as flame cutting or cutting with hot knife. And as there is no blade or other contact with the part, wear is not an issue and so a constant cut quality is achieved. Degating of parts from mould sprues is a common application.
The StarFemto, femtosecond laser system can also cut bio-absorbable polymers like polylactic acids or polyglycolic acids with high accuracy.
Cutting of composite materials is considerably cleaner with a laser based process and can be up to three times more cost effective than a water jet system.
Diode lasers are the ideal choice for plastic welding. With different wavelengths ranging from 808 to 1470 nm they provide the best foundation for welding workpieces of any colour. Whilst the laser welding process does require (in most cases) use of an absorbing pigment in one part, the low heat load, small heat affected area and clean process all have significant benefits in certain applications. For example in the automotive engineering, electronics, communications, medical device technology, human care and domestic appliance markets it is often desirable to seal sensitive electronic components into a water-proof housing and then the laser process is ideal.
ROFIN diode lasers feature scanner heads and a closed loop welding temperature control through pyrometers, therefore offering increased flexibility and process control over other methods.