A 500W Erbium multimode fibre laser source adapted for polymer welding has been developed under the European project Polybright.
The laser emits at 1567nm to weld polymers, which are known to be hard to weld because plastics only possess high laser radiation absorptivity at the longer wavelengths in the infra-red spectral range. Commercially available laser sources emitting at these wavelengths have not been available until recently.
For Polybright two laser sources - 1940nm and the 1567nm laser, both at 120W - are being used to evaluate the absorption behaviour of different polymers for additive-free welding applications. The aim of the project is to develop high power high brilliance lasers with new wavelengths between 1500 and 1900nm that are adapted to the absorption properties of polymers. Laser producer IPG Laser, based in Burbach, Germany, is participating in Polybright. IPG’s new laser source, developed under Polybright, is called ELS-500. This combines several single mode Erbium fibre lasers and feeds their outputs into a single 200μm diameter multimode fibre.
To use 1567nm for welding applications the next step is to increase the power spot sizes to overcome industry demands for positioning accuracy. The lasers will also need ‘tophat’ beam profiles to achieve the necessary spot sizes during weldng.
Polybright’s total budget is €10.2 million with €3.6 million from industry and €6.6 million of government funding. Polybright started in October 2010 with 18 partners from nine countries. Its aim is to develop high power, high brilliance lasers with wavelengths between 1500 and 1900nm, which are absorbed by polymers. According to Polybright’s website the project will end in September 2013.
