Author(s)

H. Sakamoto, S. Kawabe & S. Itoh

Abstract

The high-speed fracture process of glass bottles when using underwater shockwaves and the glass bottle recycling technology that uses this crushing technique are discussed. The proposed technique is an efficient method for the smashing and washing of glass bottles. The production cost of producing cullet, which is small glass fragments, can be decreased as a result. In this study, using commercial beer bottles, the relationship between the cullet size and various explosive conditions were clarified. Moreover, the behaviour of the underwater shockwaves was observed by the framing photograph method, the shadowgraph method and the illumination photography method, and the FEM simulation was executed in order to clarify the high-speed fracture mechanism. Keywords: glass-cullet, underwater shockwave, high-speed fracture. 1 Introduction Bottles made of glass are used voluminously as containers for water, alcoholic drinks and medicine. Many of these glass bottles are re-used as returnable bottles or recycled as the raw material for other glass bottles, in which case it is called ‘cullet’, being the small crushed fragment of the glass. Recycling by conventional methods in a large-scale crushing machine is expensive and therefore the ratio of this production method becomes lower in comparison with that of the recycling as returnable bottles. In the case of medicine bottles, almost all of them are dumped as landfill dust [1]. In this study the authors paid attention to the recycling technique for crushing the glass bottles by using an underwater shockwave [2–5]. When this technology

Keywords

glass-cullet, underwater shockwave, high-speed fracture.