Glass is a relatively transparent solid material, forming a continuous network structure when melting, cooling process viscosity gradually increased and hardened but not crystalline silicate nonmetallic materials.The remarkable characteristic of glass is its hardness and brittleness, which brings great difficulty to processing.The traditional glass processing method is mechanical knife cutting.But the mechanical cutting efficiency is low, poor, fragile, easy to passivation, damaged replacement.This requires the use of laser cutting technology to achieve high precision machining.
Glass can be used in many industries: automotive, construction, medical, display, electronic products, such as small optical filters, glass substrates for laptop flat panel displays, or large glass panels used in large-scale manufacturing fields such as automotive or construction.There are many kinds of glass, common for sodium calcium glass, also known as alkaline glass, mainly used in the automotive industry, construction industry and household appliances, the general thickness of 1.6 ~ 10mm.Glass with a thickness of 1mm or less is called borosilicate glass or non-basic glass, mainly used in the field of flat panel displays and electronic products.
Laser cutting is to use the focused laser beam with high power density to illuminate the workpiece, so that the irradiated material quickly melts, vaporizes, ablates or reaches the ignition point, and at the same time, with the help of the high-speed airflow coaxial with the beam to blow away the molten material, so as to achieve the workpiece cut.Laser cutting is one of the thermal cutting methods.There is no contact between the cutting torch and the workpiece during laser cutting, and there is no wear of the tool.
Laser glass cutting:
Melt cutting method: using glass in softening temperature has good plasticity and ductility, with focus on CO2 laser and ultraviolet laser to the softening of the surface of the glass, laser has the higher energy density can lead to glass melting, and then use air blow away the molten glass, produces groove, so as to realize the melting of glass cutting.
Crack control method:
1. Laser heating on the glass surface, higher energy will make the temperature there rise sharply, and the surface will produce a large compressive stress, but the compressive stress will not cause the glass to break;
2. Rapid cooling of this area is generally performed by cooling gas or coolant. Sharp cooling will produce a large temperature gradient and a large tensile stress on the glass surface, which will make the glass surface crack along the direction of the predetermined marking to achieve the cutting of the glass.
CO2 laser is used for glass cutting.CO2 laser emitting laser wavelength is 10.6 m, and glass can strongly absorb 10.6 m laser, almost all laser energy is absorbed by the glass surface 15 m absorption layer, so the glass laser cutting system is almost equipped with CO2 laser.