PETpla.net Insider 12 / 2013

BOTTLE MAKING 24 PET planet insider Vol. 14 No. 12/13 www.petpla.net Laboratory tests on sample bottles – Bottles, performs and closures, part 8 Mould trials and examination of sample bottles Normally the finalised mould design is used to make a single cavity for the production of sample bottles in a labo- ratory machine. These sample bottles are then tested comprehensively to see whether they meet the defined requirements. This article will cover the first steps in bottle examination from verifying the main dimensions to burst pressure tests. PETplanet insider is publishing extracts from successive chapters of Ottmar Brandau’s “Bottles, Preforms and Clo- sures”, which was first published by hbmedia. A newly revised version is reissued under the Elsevier imprint. Verifying the main dimensions In the first step, all the principal dimensions of the bottles from the mould trials are measured. These are primarily the main diameter; the points of contact that are important, e.g., for packing in cartons; the label diameter; and the overall height. Apart from cal- liper gauges and so-called Pi Tapes or diameter tapes, which permit a direct reading of the diameter based on the circumference, laser-assisted measur- ing instruments are also used. Especially for bottles designed for CO 2 -containing products, the bottom clearance is also determined. This means that the distance between the