Effects of Thermal Conditions on Sink-Mark Generation of Press-Formed Glass.
Kentaro Tatsukoshi, Yasuo Kurosaki, Isao Satoh, Yasuo Satoh · TRANSACTIONS OF THE JAPAN SOCIETY OF MECHANICAL ENGINEERS Series B · 1996
We present an experimental study on the effects of thermal conditions on sink-mark generation of press-formed glass products. In experiments, the depth of sink-marks of glass was investigated with variation of the weight of the glass, the initial temperature of the glass, the initial temperature of a plunger, the pressing time, and the pressing pressure. The obtained results can be summarized as follows (1) The depth of the sink- mark increases linearly with the weight of the glass. This is explained by the fact that the cause of the sink-mark is basically shrinking of the glass. (2) It decreases exponentially with lower initial temperature of the glass. This is explained by the fact that the viscosity of the glass increases exponentially with lower temperature. (3) It is reduced with lower initial temperature of the plunger, longer pressing time and higher pressing pressure. This is explained by the fact that the glass surface, where the sink-mark is generated, is cooled more effectively under these conditions. (4) It is most Influenced by the initial temperature of the plunger, and least influenced by the pressing pressure.