When cutting glass, lasers outshine conventional mechanical processes. Mechanical glass cutting requires very low speeds to prevent damage to the structure caused by micro-cracks and tension. In contrast, lasers use a non-contact processing method, which considerably speeds up the processing time. Furthermore, the mechanical components used in the conventional method are subject to wear and tear. As a result, they need regular maintenance to ensure the quality of the manufacturing components remains consistently high. Lasers do not have this problem.
Ultra-short laser pulses are particularly well suited to cutting glass, as the extremely high peak intensity means they can easily process the glass and produce cuts of superb quality. Alongside the beam source, another key factor when cutting glass is ensuring optimal beam guidance. Beam guidance, including along the beam axis, is an example of the latest innovations in optical technology designed to optimise the process speed and therefore enable cost-effective glass cutting. As such, with its advance development work TRUMPF has conquered the third dimension of beam guidance, which enables the beam to be tailored to the requirements of transparent materials.
With a conventional unmodified laser beam, the main aim is to achieve the greatest intensity, i.e. one that far exceeds the material's ablation threshold. However, this also wastes a lot of energy. The basic principle behind beam guidance is to distribute the beam intensity in the best possible way in order to make the process more effective. Instead of concentrating the greatest intensity on a very small area in the beam's focus, the beam intensity is distributed relatively equally over the beam axis, which maximises effectiveness. As a result, the feed rate of the laser beam (and therefore the cost-effectiveness of the process itself) can be improved by several orders of magnitude up to 1 metre per second and higher.
Summary: By selecting the appropriate laser parameters, such as the pulse energy, pulse overlap rate and repetition rate, the development of micro-cracks can be prevented, which avoids the need for expensive rework.
|Conventional method||Mechanical, chemical etching|
|Challenge||Processing that causes minimal damage|
|Lasers||TruMicro 5070 / 5270|
|Wavelength||1030 nm / 515 nm|
|Optical system||Scanner, fixed optics|
|Max. pulse energy||150 µJ|
|Speed||3 - 1000 mm/s depending on the process and geometry|
|Advantages||Processing that causes minimal damage; no rework; the non-contact processing method means there is no tool wear; any geometry can be produced with minimal corrections; flexibility|