OUTER PLANET 54 PETplanet Insider Vol. 23 No. 03/22 www.petpla.net OUTER PLANET New SodaStream bottle resin requires Sipa technology Standing up to pressure and heat SodaStream, the manufacturer of in-home carbonation systems, is known for products that transform tap water into flavoured or unflavoured sparkling soda water, at the touch of a button. The company now collaborates with PTI and Sipa to produce new generation Tritan copolyester bottles. SodaStream decided to develop a new sturdy, refillable container that would handle high dishwasher temperatures and accommodate high-pressure filling, as well as offer clarity in the material and dent/scratch resistance. SodaStream approached American company PTI (Plastics Technologies, Inc) to assist it in engineering a solution that would be appropriate for its markets and customers. PTI is headquartered in Holland, Ohio and has a European facility in Yverdon-les-Bains, Switzerland. It became part of Sipa in March 2021. Selection of material SodaStream worked directly with Eastman Chemical to identify a Tritan resin grade that would deliver the necessary properties. It was important that the resin have amorphous glass-like clarity without crystallinity and haze. The next part of the of the process was to research and develop a preform that could be commercially blow moulded. Tritan grade has to be approximately 30°C hotter than PET to make the plastic preform malleable enough for blow moulding. It was at this point that the company approached PTI to assist them in developing the right preform. After a series of blow moulding and performance simulations, PTI determined that an 83g Tritan preform would deliver optimum performance. This represented a 15% weight reduction from SodaStream’s existing 1l PET container. Prototyping trials and performance evaluations were conducted to ensure application pressure safety. The Tritan material required higher stretch ratios and reheat temperatures, compared to PET, which proved challenging for injection and reheat cycle times. Custom bottle manufacturing solution The thick-walled plastic container presented challenges in both injection and blow moulding. Special care must be taken during the manufacturing process, so that scuffing is minimised when the preforms are transported from injection to blow moulding. Sipa was able to engineer a blow moulding machine with enough lamp power to heat a very thick preform close to 140°C, without having to carry over the heat of injection for blow moulding. The process Sipa developed also eliminates scrap that had been generated when the blow moulding line went down inadvertently. Sipa’s preform manufacturing system starts with an XForm 350/48 Gen4 injection moulding unit. This can produce several different types of preform both in PET and in Tritan. Once moulded, preforms are automatically taken out by a robot fitted with a “cool pick plate” and transferred to a stabilisation station, where they remain for several cycles. Transfer and bottle blowing Preforms are then picked up by a second robot; a six-axis anthropomorphic type, fitted with special end-of-arm tooling equipped with vacuum suction, and immediately transferred to a Sipa SFL 6/6 Evo linear stretch-blow moulding machine.The bottles are formed and then transferred using star wheels and subject to 100% in-line optical scanning, to ensure their quality. www.sipasolutions.com Sipa integrated injection and blowing solution for zero defect bottle Robotised preform transfer
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