The international application for the invention (sent to the World Intellectual Property Organization, WIPO, in June 2012 and published globally in December 2013) describes a method that includes the use of an internal plastic liner for a barrier.
Although it is unclear what applications the soft drinks giant might have in mind, carbonates are clearly problematic – other ‘paper bottles’ on the market cater for wine, juice and milk.
A 'step forward' for sustainability and the environment
Told about PepsiCo’s paper bottle patent filing this morning CPS International director Andrew Streeter, a packaging expert, told BeverageDaily.com: “The way you describe it, it sounds new.
“I would have thought that for CSDs it wouldn’t be good enough for three atmospheres (atm), but may work for partially carbonated drinks – draft beer for instance,” he added.
“I haven’t seen the patent but it sounds like a good step forward for sustainability and the environment generally – it’s an obvious material to use,” Streeter said.
PepsiCo’s patent filing notes that recent efforts have been made to form bottles from a fibrous pulp, such as a cellulosic pulp of the type commonly used to make paper products.
“Such bottles provide potential for a significant reduction in the consumption of plastics used for making bottles, and since they can potentially be manufactured using recycled paper – pulp-molded bottles may be more environmentally friendly as well,” the firm’s filing states.
It describes how, after constructing a wet paper preform – a pulp fiber slurry is applied to a papermaking mold with ‘suction paths’ or drainage channels, which draw water out – the wet preform is press dried by expanding a thermoplastic parison (preform) against it via blow molding.
PepsiCo also describes an alternative method that sees moist fibrous sheets, with 50-70% water content by weight, arranged in cylinder-like shapes.
'Unacceptable' shrinking issues overcome
Then either the bottom of the cylinder is pushed or deformed inwardly to form the container base, or one or more sheets of paperboard is placed at the bottom of the package to craft its base.
The mold is then closed around the moist paperboard form and a vacuum applied to pull the paperboard (which is dewatered by both heat and pressure) against the inner wall of the mold.
As with the first method, the ‘pressing’ is achieved using a thermoplastic parison that is expanded against the wet preform by blow molding.
PepsiCo also describes methods for overcoming “unacceptable” ‘shrinking issues’ – shrinkage and separation between the plastic liner and fiber wall that risk damage to the bottle structure.
Does paper have plastic's sex appeal?
Reflecting on the prospects for a paper bottle, which would compete with established options such as cans, cartons and PET, Streeter said: “There are two issues to consider in terms of making something like this a marketplace success.
“One is coping with lack of product visibility – competing with liquid cartons head on,” he said.
“Second, the facility to shape and not create a utility finish. Shaping was an issue for a Japanese paper bottle – I think it was injection molded – that used a fine plastic liner, for use with detergent. That didn’t have the sex appeal that a plastic bottle could achieve,” Streeter warned.
California-based wine production, sales and marketing firm Truett-Hurst launched the first paper wine bottle nationwide (designed by UK firm GreenBottle) in the US last November with Safeway.
Paper Boy delivers first paper wine bottle in US
Truett-Hurst touted the light weight of the bottles, used with its Paper Boy brand (85% lighter than glass with a case weight of 23.6lbs versus 36lbs), and a significantly reduced carbon footprint.
The brand's rebellious positioning was also interesting, since it is sold as as "a wine that breaks rules, breaks barriers, breaks the way we enjoy wine, even where we experience it".
At the time, winemaker Virginia Lambrix of California's VML Winery was also enthusiastic: “Wines that will be consumed almost immediately do not need a heavy, environmentally and economically expensive glass bottle and cork,” she said.
“We would rather apply the savings that Paper Boy affords towards more expensive, better-crafted wine,” Lambrix added.
You can consult PepsiCo’s paper bottle patent filing in full here.