PETpla.net Insider 08 / 2014

CAPPING / CLOSURES 15 PET planet insider Vol. 15 No. 08/14 www.petpla.net Welcome to visit TECH-LONG CHINA BREW CHINA BEVERAGE 2014 No. 23 Yunpu 1 Road, Luogang District, Guangzhou, 510530, China Tel: +86 20 62956800 Fax: +86 20 82266913 www.tech-long.com E-mail: market@tech-long.com TECH-LONG PACKAGING MACHINERY CO., LTD. BEVERAGES HOUSEHOLDS CONDIMENTS DAIRY BEER Booth: E2C67 Date: 2014 10.13-16 Add: New China International Exhibition Center, Beijing,China analysed under the same or very similar conditions to those in which it will be deployed. The false-colour photo of the cap’s cross-section (Fig 1) reveals that oxygen permeation through the closure is occurring solely through its flat region (highlighted in the oval area). In the threaded area (identified by the green arrow), where the cap mates to the bottle neck, air has an almost free access to the neck itself. It is, consequently, the bottle’s PET material that allows permea- tion in this region. The transition between the bottle and the cap’s seal- ing is a particularly sensitive area and it is essential that a cap should be tested on the thread of the bottle. The program therefore undertook testing with a closure fitted to a preform neck that had been cut from the rest of the bottle. It is also important to measure the performance of a preform neck fitted with an impermea- ble aluminium top. The results enable determination of the permeation rate of the cap independently of the preform’s threaded area. A preform with a suitable thread from any supplier can usually be used as a standard for testing cap modifications. For a final permeation result, however, it is better to test the cap with the preform that is to be blown into the bottle on which it will be fitted. This eliminates variations in the selection of the PET master batch. The interface between the closure and the package is highly sophisticated and it is best to include this area in the test. Systech’s advanced oxygen permeation analysers are capable of testing the oxygen barrier properties of packages with a detection threshold of 4E-05cm³/pack/day. All the cap samples and preforms tested have been collected from recent packaging industry shows and exhibitions. In the case of bottle caps, the bottle necks, caps and preform threads with the aluminium shims are glued directly on the platen of the permeation ana- lyser. A rapid setting epoxy resin seals the caps and preforms onto the platen, quickly and easily. Pairing of caps to preforms has been done randomly. In this case study, it is the test principle and proce- dure which is of interest. The variety of available cap systems in the market cannot be measured in the frame of an application report. Oxygen transmission rates for this random selection of caps have been measured between 8.3 E-02 and 1.47E-02 cm³/cap/day, including a contribution from the preform neck. The contribution of the neck itself is in the range of 2.6 to 2.16 E-03cm³/ neck day and has to be deducted from the values in the diagram. www.systechillinois.com