PETpla.net Insider 04 / 2019

BOTTLE MAKING 43 PET planet Insider Vol. 20 No. 04/19 www.petpla.net German Technology May 21-24, 2019, Guangzhou Hall 5.1, Booth S27 Strech Blow Molding, part 11 - Machine details: Changeover times Machine details by Ottmar Brandau Ottmar Brandau has newly revised his book “Strech Blow Molding”, first published by hbmedia / PETplanet Publisher, and now re-issued in a third edition under the Elsevier Imprint. PETplanet Insider is publishing extracts from successive chaperts in a serie of articles. Changeover times Changeover times are important for those factories that do not have the luxury of running the same prod- uct 365 days/year but have to change 2–5 times per week. When the same necks are used, the steps involved are as follows:  disconnect water hoses  replace blow moulds  replace bottom inserts  replace stretch rod stops or dial in new stop values  change PLC recipe  change preform supply. All blow machine manufacturers have now quick-change systems (fig. 4.18) that make this task much less time consuming.  Water hoses are equipped with quick-disconnects or eliminate the disconnection completely by feeding water through the carriers with the moulds being outfitted with O-rings that do not require anything to be discon- nected.  Blow moulds used are mounted with two screws holding each half. Modern systems feature locking mechanisms that allow mould removal with one twist of a special tool or no tool at all.  Same for the bottom inserts.  Stretch rod stops are also easily replaced or not necessary when servomotors are used instead of cam-driven pneumatic cylinders. Taken all measures together may reduce changeover time from 5 min/cavity to less than 1 min/ cavity. On a 20-cavity system, this would result in time savings of 80 min/changeover, allowing an additional production of over 53,000 bottles if the machine runs at a speed of 2,000 bottles/cavity/h (b/c/h). Even if the margin was only 0.5 cents/bottle, an additional rev- enue of $ 250 per changeover could be achieved. Figure 4.18 This tool-less system allows mould changeover in less than 1min/ cavity. Picture courtesy of Sidel Inc. Please order your copy at the PETplanet Insider book shop: www.petpla.net/book3 Stretch Blow Molding Third Edition by Ottmar Brandau € 130,00 374 pages © Copyright Elsevier 2017, 2012