Papers by Keyword: Glass Cutting

Abstract: To ensure the scribe-wheel is always forward along the tangent direction of the cutting path, a new planning algorithm is proposed for the cutter shaft rotating control. The short linear segments used for approximating the cutting curve are separated by the equipartition conditions. For the satisfied ones, the angle between the adjacent segments is linearly interpolated and the cutter shaft rotates without stopping the machine. Otherwise, it needs to stop and rotate the shaft. The experiments show that the deviation error of scribe-wheel is small, and the error existing period is short, which proves the algorithm can achieve the scribe-wheel tangential tracing and satisfy the accuracy requirements while cutting complex shapes.

Abstract: A 532nm Diode-Pumped green laser was used to cut glass with the Micro-Crack control. The Micro-Crack was the micron-sized round-like crack caused by laser in the glass and the line-crack around the round-like crack. This paper researched the generation of the Micro-Crack and discussed how to control it, then researched the stress field in the glass during the cutting by finite element analysis. Propose a new method about the glass cutting which had advantages of low power, low heat effect, irregular-curve cutting and slant cutting.

Abstract: This paper indicates the experiments of YAG laser cutting soda-lime glass with controlled fracture. The qualities of glass obtained by laser cutting and mechanical cutting are compared. The impact of laser power, scanning speed and spot size on the cutting quality is studied and the optimum laser parameters are given. Finally the experiments of laser cutting two-layer glasses, glass tube and laser cutting in curve paths are carried out. The results show that good cutting quality of glass can be acquired by YAG laser cutting.

Abstract: In laser cutting of glass with controlled fracture, thermal stress induces a fracture and the material is cleaved along the cutting path by fracture propagation. Compared with CO2 laser, YAG laser has many advantages in cutting glass with controlled fracture. As a volumetric heat source, YAG laser can penetrate through the glass. Therefore, the temperature distribution is uniform across the thickness of the glass and the fracture propagates from the top and bottom surface to the middle so that better cutting quality can be acquired and multi-layer glasses can be cut simultaneously. In this paper, a 1064nm YAG laser is applied to cut two-layer and four-layer glasses. Fracture propagation mechanism is studied by examining the temperature and stress fields using finite element software ANSYS11.0. Good cutting qualities of fracture surfaces for all the layer glasses are acquired and the cutting efficiency is greatly improved by this technique as well. Additionally, due to smaller laser spot size the glasses that are closer to the focal point have higher laser power density inside glass, which may lead to ablation and evaporation phenomenon. But lower laser power density is not enough for fracture initiation and expansion. Therefore, it’s important to find a proper laser power for all the layer glasses. Small tensile stresses on the top and bottom surfaces will make the material separate from up and down to middle, whereas the compressive stresses in the middle ensure stable fracture propagation. Moreover, the stable fracture propagation always lags behind the laser beam spot. High tensile stresses are distributed throughout the thickness of the glass in the leading and trailing edges, which leads to unstable fracture extension in the leading and trailing edges.

Abstract: With more and more applications of glass in advanced fields of science, the demand for glass machining precision and efficiency has increased greatly. More and more attention is being paid to glass cutting by ordinary tool because precise glass parts with various shapes can be obtained at high efficiency and low cost. But, in this method, rounded cutting edge radius of tool has important influence on precision and integrity of surface. This paper presents the laws of glass crack initiation and propagation when a cylindric indenter is used for glass indention. Research results show that two cracks that are symmetrical to the normal plane of the indentation surface occur suddenly when the load increases to a critical value. Closing occurs in the two cracks during unloading. The interior angle between the two cracks and critical load increase with rounded edge radius of cylindric indenter linearly.