Other suppliers, too While some of Suntory's mineral water goes to market in Monotherm bottles blown by Mitsubishi, the firm relies on other makers of heat-set bottles, too. So the firm joined with Krupp in developing new technology. Mitsubishi management saw an opportunity in heat-set PET bottles, but they didn't want to be restricted by licensing arrangements that typically come with other heat-set technologies that are available. One obvious advantage Suntory gains is that with an additional supplier in the game, pricing is more likely to remain stable. Neither Suntory nor Mitsubishi representatives could be reached for comment, so it's difficult to compare Monotherm with other heat-setting technologies in this particular application. Suntory uses the heat-set container to hot-fill its mineral water in one-way 2-L bottles with a 28-mm neck finish. Says Koch, 'In Japan they want to eliminate any chance for water-borne health problems.' Suntory of Osaka, Japan, is one bottled water marketer filling bottles produced on the Monotherm system operating at Mitsubishi. Apparently, water is not hot-filled anywhere else.

Bottled water is among the applications for which this technology is suitable, though Japan may be the only place that's true. He was then general sales manager at Krupp now he's with Husky Injection Molding Systems (Bolton, Ontario, Canada). Michael Koch described the Monotherm system in a paper delivered at Bev-Pak Americas '95, held last April and sponsored by Directions 21, Inc. Compared to a conventional blow molder producing carbonated soft drink bottles, the Corpotherm heat-set process costs 73% more, while Monotherm bottles are 56% more costly. It's also more economical than Corpotherm (see Table 1). The Monotherm, as its name suggests, requires just one blowing wheel instead of two, so it's simpler to operate and occupies less plant space. The downside to the Corpotherm system is that it required two blowing wheels, which made it complex and costly. With Monotherm, Krupp replaces its Corpotherm heat-set PET system. Developed jointly by Krupp and Mitsubishi Plastics (Tokyo, Japan), the first Monotherm system to go into commercial production is at a Mitsubishi facility in Japan. Commercial blowmolders wishing to provide food and beverage marketers with polyethylene terephthalate bottles that can be hot-filled at up to 95☌ (203☏) now have a new option: the Monotherm system from Krupp Corpoplast (Hamburg, Germany).

Preform blow molding