A new large PET mineral water bottle configuration, developed by SIPA’s own Research & Development team, provides important savings for the customer while improving sustainability. The eight-liter bottle has the same 38-mm neck size as a five-liter version, so changing between sizes in production takes relatively little time.

This makes an important change from the common practice among manufacturers of large bottles producing formats in various sizes. Numerous producers, most notably in Europe’s Iberian peninsula, already provide PET bottles in both five- and eight-liter formats, but the larger bottles are virtually always made with wider necks, 48 mm in diameter (the same as used for 10-L bottles).

This means that, when switching formats, time is needed not only to change the mold for the bottle body, but also for the neck. Using a 38-mm neck for both formats takes care of that issue. Plus, preforms with a 38-mm neck are lighter – around 6g lighter – than preforms with 48-mm necks, lower in cost, and more available. On top of that, caps for the narrower neck are easier to find on the market.

The SIPA design team created a special design for the 8-L container, with a very attractive and equally functional wave pattern that gives an optimal stretch ratio of the preform and also enables excellent top load and side load resistance levels – which are obviously extremely important parameters for large format containers.

This was an extremely delicate development, made possible thanks to the extreme flexibility and versatility of the SIPA SFL linear stretch-blow molding platform. An SFL Dynamic 2H can produce up to 1100 bottles per hour per cavity for example, while other models in the range such as the SFL Performance 3H, SFL Big 4, and SFL Maxi 3, are also suitable for such bottle sizes.

Sustainable large bottles: