PETpla.net Insider 06 / 2019

PET planet Insider Vol. 20 No. 06/19 www.petpla.net 20 JUBILEE Future trends in PET bottle processing After looking back to the very beginning and some highlights of PET bottles, we also thought about future trends in PET bottles processing. We picked out some very new design and processing developments. Some topics come always in mind when thinking about PET bottle design today: less weight, the percentage of rPET and recyclability. Two process developments in reducing weight of a PET bottle came from the company Redupet. First we would like to present Mint- Tec which is a new technology to mint the shape of the preform-base into its optimum design for the fol- lowing blowing process. The effect is a significantly reduced wall thick- ness of the preform base, while the surface is increased. As the warm- est spot of a preform after injection moulding is the base, it needs very little force to shape it to its optimum design. Base optimisation The special minting unit is shap- ing the conical or spherical base of the preform directly after injection moulding in the first heat. The mint- ing unit is designed to use the reheat effect directly after the injection mould to decrease the wall thickness and to increase the outer surface of the preform through a gentle, but fast minting process. At the end of the shaping process the preform gets in contact with the cooling sleeve, were the cooling is very fast due to the reduced wall thickness and the increased outer surface. There is no modification neces- sary of the existing mould, only a core change is needed for weight saving. The take out and transfer device of the preform production system needs to be replaced for existing moulds. The Mint-Tec device is mounted on the transfer plate of the injection moulding machine while the cooling sleeves on the take out device are delivering the counter design. Fast, precisely and without damaging the preforms, the Mint- Tec device is shaping the base of the preforms through the minting process. Mint-Tec allows a saving of 3-5% of the total PET bottle weight. In the trend to less weight it extended sur- face and reduced wall thickness at the base. The injection and the blow moulding process are shorter. This patented technology leads to material- and energy savings. Neck optimisation The second place to reduce weight is the neck: Neck-Light tech- nology allows to further optimise a modified preform-neck for the subse- quent blowing process. The effect is a significantly reduced wall thickness of the preform neck, while the outer sur- face is increased. As a result, reheat- ing in the blow moulding machine is far more efficient. To manufacture this kind of thin-walled neck area under the thread for flat and CSD applica- tions especially developed melt-flow channels are installed to ensure a common injection moulding process while keeping the bottle quality at the same level. The thin-walled preform neck absorbs much IR light which means that stretch blow moulding is more efficient with a wider process window. The modification of an exist- ing mould is possible by an exchange of the neck-splits. Neck-Lite is part of the injection mould. Thanks to espe- cially designed channels in the neck splits the hold pressure is maintained in the neck thread during the moulding process. This prevents the other- wise feared sink marks in the precise neck area. With this technology 2-3% weight is saved. An example is given: a preform of 10.5 g for 0.5 l of still mineral water with 128 cavities of Neck- Lite design has an effective weight reduction from 10.5 g to 10.2 g = 0.3 g per perform. 208 t of PET resin per year are saved. Design: Clasper blow moulded bottle technology by PTI This snap fit technology provides a unique packaging solution for food, beverage, pharmaceutical, nutra- ceutical, industrial, and household chemical products. The Clasper blow moulded PET bottle is available to brand managers pushing products in a package that requires two separate containers. The Clasper double-bottle concept provides a solution for products that cannot be premixed or must be con- sumed in sequence, which opens the door for new product categories and creative product development. It gives consumers a unique usage experi- ence, which is sure to delight. Some features are including: a bottom container that can snap into the base of a larger top bottle. It has the ability to be blow moulded in vari- ous sizes. It can accommodate liquids or powders and is also available for hot fill applications. There can be a heat or induction seal for bottom con- tainers with traditional closure for the top bottle and shrink sleeves can be used to promote branding and provide usage instructions. Typical markets for this Clasper blow moulded bottle technology are the beverage and food, personal and healthcare as well as the pharmaceutical market. Deep Grip bottles Deep Grip is an injection stretch blow moulding (ISBM) process to create a new type of container handle. Deep Grip technology enables sig- nificant grip depth with an extremely thin grip “web” thickness. The grip is deep enough for the average hand to completely close around without finger