PETpla.net Insider 05 / 2010

CAPPING / CLOSURES 34 PET planet insider Vol. 11 No. 05/10 www.petpla.net Some like it hot PET bottles for hot-fill applications were first intro- duced in North America in the 1990s and have been widely adopted across the world since then. The majority of closures have been two-piece but they have several disad- vantages, including weight and complex process requirements. Developments in one-piece closures have enabled them to become more and more widely adopted as solutions for hot- fill products. The market for hot fill products Hot fill applications have been around for decades in, for example, the fruit juice bottling business. All juices, nectars and juice drinks filled in glass bottles in the past have been bottled under hot fill conditions in order to decontaminate the packag- ing material (the inside of the bottle and the closure) with the hot beverage itself (between 85 and 92°C in gen- eral). They also help to achieve a long shelf life, ranging from several months up to one year, depending on the type of juice, the temperature of the liquid and its time in contact at hot tempera- ture during filling. The PET bottles introduced for the first hot fill applications had some spe- cific designs in common. The body, which had to be temperature-stable, includes absorption panels to control deformations caused by variations of temperature and vacuum created during cooling. The neck needed to have a relatively thick wall, even crys- tallized initially, in order to withstand the distortion during the hot fill proc- ess and to provide heat stability. In the beginning, closures were (and still are, in many instances) two- piece, built with an elastomeric liner applied inside the closure shell. It pro- vides a secure seal once screwed on the bottle neck with a high torque. Dis- DoubleSeal 28 HF Chart 2: North America: development of hotfilled juices, energy drinks, etc. (Source: Bericap) Chart 1: Europe: development of aseptically filled juices, energy drinks, etc. (Source: Bericap) Bericap’s one-piece closure for hotfill - in Asia since 2003 Global development of filling proc- esses replacing glass bottles with alternative packaging systems dif- fered in regions across the world. In Europe, the glass bottle was replaced mainly by PET aseptic systems, which still dominate today (see chart 1). Hot fill applications in North America moved into PET bottles in the 1990s and the trend continues, unbroken, up to the present day (see chart 2). Asia began hot fill applications with glass and moved to PET bottles around the year 2000. It is now, following a health trend, turning to aseptic applications, which promise better product qual- ity because of shorter-period heating, thus minimising distortion of vitamins in the filled product.