Laser cutting of birch pulps

Laser cutting offers unique possibilities for different production systems. So far the utilisation has been most advanced in cutting of metal products. Lasers have also been used for paper and board cutting in some specific applications. This document, which concentrates on the physical phenomena of laser cutting of birch pulp, is part of a national project performed in Finland about laser cutting of pulp, paper and board. The research was carried out with a 2.7 kW HQ laser, with a focal point diameter of 80 μm and a work cell designed and manufactured for the project. These experiments were carried out with a pure birch pulp manufactured for the experiments, and with three different densities. The experiments cover the effect of laser power, focal point position, material thickness, direction of the polarisation plane, cutting gas pressure and nozzle stand-off distance on the cutting speed and cut edge quality. From the experiments it can be seen that all of the variables have an effect on both the cutting speed and the cut quality.