Sidel is launching FreeShape™, the first PET bottle that can be used for the packaging of sensitive beverages aseptically or by hot fill with a single shape. How? It’s all thanks to the overstroke base technology.
Hot fill or aseptic? Bottle shape constraints related to the choice of filling technology are no longer a consideration with FreeShape™. This innovative bottle needs no panels due to its overstroke base, and in addition to shape freedom, it also offers the possibility of using a single bottle for both types of filling. This development is based on an in-depth knowledge of material characteristics, aseptic packaging, hot filling and blow molding technologies.
A membrane base
The secret of FreeShape™ lies in its patented bottle base profile, which acts like a membrane or piston: it rises and falls depending on variations in the volume contained within the bottle. This innovative solution responds to the packaging needs of sensitive products such as juices or teas filled at temperatures between 85 and 92°C, which lead to bottle swelling during hot fill and then shrinkage when the liquid is cooled.
Hot fill or aseptic: Just one bottle
The overstroke base is an innovative alternative to the traditional solution of flexible panels designed on the bottle body to absorb volume variations. It opens up new shape possibilities that until now could not be used on this type of bottle, while also ensuring better visual impact on consumers. With FreeShape™ and its overstroke base, a single bottle shape can be used, regardless of the bottling technology in use: hot fill or aseptic. FreeShape™ therefore revolutionizes sensitive beverage production: bottlers no longer have to develop two different bottle shapes for a product, and they now get better production flexibility between their lines. They can also capitalize better with consumers on this single bottle shape as a brand element.
Overstroke base technology
The overstroke base technology consists in separately managing the rise of the mold base with respect to the closure of the body shells and the blowing of the bottle. The base continues to rise inside the mold once the latter closes, thus improving the mechanical performance of the bottle base. The unique FreeShape™ bottle solution illustrates Sidel’s know-how in managing the process sequence. First, the bottle is pre-blown, before the base has entered the mold. The mold base then rises higher than the level of a traditional mold base, lifting the material between the body wall and the mold base to create a small circular lip that significantly stiffens the diameter of the bottle support.
An economically competitive bottle
The 500-ml FreeShape™ bottle weighs just 28 g, which is the weight generally obtained with a paneled bottle for hot fill. This solution is particularly competitive when compared with hot-fill panel-less bottles on the market, which weigh 32-34 g on average. In addition, its design makes nitrogen use unnecessary.