SIPA develops BPA-free five-gallon water bottles

Polycarbonate (PC) used to be king when it came to the five-gallon water cooler market.

But over the past few years, concerns about one of PC's building blocks, BPA, have resulted in a public debate about the potential health risks from PC bottles of all sizes, which includes the popular five-gallon water bottles. BPA is now effectively banned in baby bottles in North America and in Europe and time will tell if bans will extend to other bottles.

With the U.S. market for five-gallon water cooler bottles up for grabs, PET processing technology supplier SIPA has developed a PET version that features an integral handle - also in PET.

Martina Bottarel, manager of communications for SIPA, told PlasticsToday the company had a specialized focus on the development of the five-gallon PET containers to serve as an alternative to PC.

"Many producers of five-gallon water bottles are now looking for BPA-free alternatives to PC, even though there is no legal requirement yet for them to do so," she said. "PET is one of these possible alternatives, and in fact some five-gallon bottles made in PET have been on the market for several years now."

However, she said the challenge was to produce the lightest possible container while still ensuring optimum mechanical performance. SIPA set out, not only to develop a lighter container, but one with an embedded handle for better functionality.

The starting point was a 690-g container with a polypropylene handle that is already on the market in the U.S.

Still, the company didn't want to stop there, working to produce a bottle that is made entirely of PET.

The new version features a PET handle in place of polypropylene, so when the time comes for recycling, there is no need to separate the two parts, which can simplify the procedure and cut costs, she said. SIPA developed a preform with a lightweight neck and base and added material in the area of the body where the handle is attached during the blowmolding process.

The new design is suitable for production on a SIPA SFL 2/2 two-cavity linear stretch-blowmolding system. Trials have shown that output rates of 250 bottles per hour and per cavity are possible, which is around three times as much as achieved with PC bottles.

Bottarel believes the PET handle is a real differentiator, since handles are typically made with PP.

"The handle material with 100% PET is an important development, because it eliminates the need to separate the base and handle once the bottle reaches the end-of-life phase," she said. "The weight of the container is also lower, it is 665-g for the PET container and only 53-g for the PET handle. It is significantly lower than the average bottle weight offered by other companies."

Bottarel said the market for five-gallon bottles is about 80/20 (PC/PET) since PC was the chosen material for many years.

"This leaves enormous opportunities for conversion to PET in the near future, especially if the legislation accelerates the BPA ban for such container types," she said.