Investigation of solar float glass hole cutting using 532 nm nanosecond pulsed laser

Solar float glass is widely used in photovoltaic field to make solar double glass module, because of its high visible light transmittance. 532 nm nanosecond laser was selected to cut solar float glass at a thickness of 2.5 mm, while cutting path was planned by a hybrid bottom-up multilayer increment and the spiral line method. Considering the influence of parameters (scanning speed, laser pulse repetition rate, spiral width and spiral overlap ratio) on surface quality and cutting efficiency, 37 groups of single-factor cutting experiments were designed and carried out. The results indicated that when the laser pulse repetition rate is 55 kHz, the corresponding laser power is 22.6 W (single pulse energy: 0.41 mJ), the scanning speed is 300 mm/s, and the spiral trajectory parameters are 0.45 mm and 70 % respectively, the chipping width has the minimum value of 104.81 μm and a high cutting efficiency with a material removal rate of 4.712 mm3/s was achieved. The increase of four parameters can also improve cutting efficiency, but spiral overlap ratio has little effect. The laser processed surface defects, such as micro-cracks and voids are also less when the chipping width is small, and the content of surface elements is much closer to the glass substrate.