PETpla.net Insider 05 / 2014

EDITOUR REPORT 18 PET planet insider Vol. 15 No. 05/14 www.petpla.net Five years ago saw the inauguration of Shefa’s project to fill PET bottles with UHT milk. The project was subse- quently implemented in December 2011. In response to my question to Paulo Vitor R.Mendonca of Shefa as to why PET bottles for milk and why UHT and not, for example, fresh milk, I received the following answers: “The market for milk is very large in Brazil, 67 billion litres are consumed each year. The packaging consists almost exclusively of drinks cartons with a shelf life of four months,” said Mendonca. ”What the market is looking for is an alternative which is more attractive to the user in terms of handling and appearance. PET bottles with the right barrier technology, a large diameter outlet, the appearance of a glass bottle and which were, in addition, also microwave-friendly promised to become the alternative we were looking for. PET is also readily recyclable.” He continued, “Something else that is helpful when it comes to decisions of this kind relates to the Brazilians’ shopping philosophy. They shop once a month, so buying fresh milk is something that simply never occurs to them because of its short shelf life. As far as container size is concerned, 1l bottles tend to dominate”. PET bottle specification  1l PET bottle, 2-layer, light (in the range of 400-580nm) - resistant min. four months  Bottle weight: 26g  Aseptic bottling  Aluminium foil seal. The seal is, technologically speak- ing, not necessary, but is regarded as security against any unauthorised opening of the bottle.  Plastic closure 38mm (1-piece)  OPP label  Packaging: six milk bottles in shrink film  Fully automatic palletising Technology and machine systems The Prelactia Process developed by Netstal is applied as light barrier. The preform is manufactured with 2 x PET layers using the over-moulding- process. There is an exter- nal layer in white with limited light barrier; the internal layer is dark and blocks over 99.9% of the visible light. The Prelactia Process permits the use of a lower quan- tity of titanium dioxide for the light barrier and as a result of mould core stabilisation. It is possible for the inner layer to be injection moulded so that it is considerably thinner than the external layer. The preform wall thickness of approxi- mately. 3mm that can be achieved by so doing results in a cycle time of 11.8s for a 24-cavity preform system. Cur- rently in use are 2 x 24-cavity preform machines of the Netstal Synergy 2400 type as well as Piovan drying and materials handling systems. Paulo Vitor R. Mendoca in front of the Krones labelling- machine for PET milk bottles A further Netstal Synergy 2400 injection moulding machine incorporating a 32-cavity screw capping mould takes care of plastic caps production. A 38mm screw cap closure with a weight of 2.4g is running in a cycle time of 4s. The preforms are stretch blow moulded on a Sidel stretch blow moulding machine with a capacity of 18,000bph and transported through the wall of the factory directly to the aseptic Stork Holland bottler via an air con- veyor section with a 2min buffer. The stretch blow moulding capacity is tailored to the filling capacity. Subsequently, the system proceeds directly to the aluminium foil sealing operation, screwing down the plastic caps, labelling and presentation in six-packs. Once in the six-packs, a fully automatic process trans- ports the milk bottles via a tunnel into a different bay where they are palletised. The entire PET bottling plant operates 24 hours a day. In order to safeguard filling capacity, the company maintains a stock of preforms and screw caps amounting to 1 million parts of each item. Future prospects The first stage with a total capacity of 92 million PET UHT milk bottles per year is already inadequate. Demand is exceeding capacity. Today they are only ser- vicing the Federal State of São Paulo with its population of 42 million. The next stage, which involves expansion to 200 million per year, is intended to go beyond this. A further Prelactia over-moulding preform machine is on its way to Brazil. Another PET bottle size, with a content of 0.5l is under discussion but is not a priority item.