ブロー法により成形したパリソンの肉厚について

抄録

In forming a glass container by the blow-blow method, parison is formed in a blank mold by air blow. It is then blown in a blow mold and inflated to form a bottle. Since the final shape of a bottle is designated from the beginning, the final wall thickness of a bottle is controlled by the shape and the wall thickness of an intermediate product parison. In this way the design of parison is important, but it is difficult to study how parison is formed as glass materials to be formed are extremely hot. With this in mind, the author used silicone oil in place of high-temperature glass and measured temperature at which parison is produced and the wall thickness of parison being produced. The author also studied, from the calculation of glass flow, the relationships between variations in equal temperature distribution and temperature of parison and the wall thickness of parison. In addition, the author studied causes of bottom wall thickness and waved faults and countermeasures to be taken. The result is that we have reached the following observations: (1) The wall thickness of parison from its mouth to gob line is closely related to the flow velocity of glass material and is nearly proportionate to the parison diameter. (2) Variations in the temperature distribution of parison according to glass temperature, mold temperature and the length of time during which glass stays in a blank mold cause the flow velocity of glass material to change which in turn affects the wall thickness of parison. (3) The wall thickness of the bottom below the gob line decreases or increases depending upon the length from the gob line to the bottom of parison (the surface area of glass in contact with the mold).