Brittle material cutting by laser, which is performed below the glass transition temperature, exerts no external force on blanks and leaves no need for grinding as it ensures smooth edges and clean cutting.
The controlled cutting technique generates tensile stress along the cutting path and maintains the temperature below the glass transition temperature. With this technique, it is difficult to control fissure propagation inside the glass because of its cutting characteristics and stress distribution. What is important for it is to generate precise temperature and thermal stress fields and to decrease the cut deviation at the leading and trailing edges of glass.
Kim Yong Il, a researcher at the Institute of Nano Science and Technology, has built a finite element model for temperature and stress fields of glass, established boundary conditions, and studied the effect of laser cutting speed on minimizing the cutting path deviations at the leading and trailing edges while decreasing the thermal stresses.
Through the simulation, he has proved that the cutting deviations at the trailing and leading edges seem to be decreased remarkably at the optimized power and cutting speed during continuous laser cutting. In addition, he has predicted that continuous laser is not suitable for soda-lime glass of 5mm in thickness above 900W of mean power and 22.5mm/s of scanning speed.