After beverage packers worldwide moved to two-layer multipacks for cans, a brewer in France claims to be the first to stack glass bottles. In June '96, the Armentieres, France, brewing operation of Interbrew began distributing glass bottles of Stella Artois in two-layer paperboard multipacks in France. (Interbrew, headquartered in Leuven, Belgium, is the fourth largest brewer in the world, following its 1995 acquisition of Toronto-based Labbatt Breweries.) Packaged in 24- and 30-count multipacks, the 25-cL (8.5 oz) bottles are packed on a Twin-Stack® double-stacker from Riverwood Intl. (Atlanta, GA). Originally designed for cans, this machine was re-engineered by Riverwood to handle bottles. Interbrew represents the first commercial installation. The pack itself is a pre-glued blank with two open ends, much like an enormous folding carton. The paperboard is Riverwood's Aquakote wet-strength carrier board in a 23-pt thickness, offset printed in five colors plus varnish. A separate divider pad is placed atop the first layer of bottles, much like a miniature tier sheet. It consists of two plies of 18-pt wet-strength board glued together, which Interbrew is using as additional billboard space for promotional copy. To complete the package, a handle, consisting of two plies of kraft sandwiching a polyester reinforcement strap, is glued onto the pack during carton manufacturing. Unique to this package is that the four side walls taper inward near the top, to follow the sloping curve of the bottlenecks. This tapered design was necessary to hold the bottles tightly together, preventing them from clinking and rattling during distribution. Building enthusiasm Interbrew's brand manager for Stella Artois, Cline Quevarec, says that by being first in the market with a two-layer glass pack, Interbrew hopes to build consumer enthusiasm for the brand. It's Interbrew's flagship beer in France, and is third in market share there. On the store shelf, the paperboard package has two advantages over single-layer packs: it provides a larger billboard area for graphics, and it permits more facings across a given width of shelf space. (However, half of the brand's sales are in huge, warehouse-like stores where beverages are merchandised right from the pallet.) Finally, consumers perceive a two-layer package to be lighter and easier to carry than single-layer packs, according to research cited by Interbrew. Quevarec says it's difficult to judge the success of this pack in light of the precipitous drop in overall beer sales this past summer in France. Interbrew attributes the decline to poor weather. However, amid these declines, sales of the Stella Artois brand remained even, an encouraging sign for the company. Interbrew hopes next summer's market will prove more telling. Two infeeds The 24- and 30-count multipacks are produced at Interbrew's Armentieres bottling plant. After bottles exit the filler single-file, they enter a lane divider, which produces four lanes of bottles for 24-packs and five lanes for 30-packs. The flow is then split into the machine's two separate infeeds, one for the lower layer and one for the upper. Once in the infeed, bottles are segregated into groups of 12 or 15 (for 24- and 30-packs respectively) by moving flight bars mounted on a chain. Meanwhile, cartons are picked from a rotary mechanism, squared up and inserted into moving pockets. The picker's design was specially modified to better control the paperboard blank, which is un-wieldy due to its large size. Once the bottles are grouped, the first layer is pushed into the side of the open carton by cam-activated pusher arms. Leading the bottles into the carton without having them tip was one of the central challenges in getting this machine to work. Riverwood modified the design of the pusher arms so that they push the bottles in a slightly staggered or diagonal formation, thus increasing bottle stability. Once the bottles are in, they're given a last push to fully square them. A second rotary picker mechanism picks up and deposits the divider pad atop the first layer of bottles. The top layer of bottles is then accumulated and pushed into the pack in a fashion similar to the first. A rotating flap tucker wheel then brushes the side flaps closed, after which hot melt adhesive is applied. The top and bottom flaps are folded down by static guides as the pack is conveyed forward. Finally, packs pass through a belt compression section before exiting the machine. Speed and flexibility Manuel Hutin, Interbrew's production manager, says the machine easily keeps up with the 60ꯠ-bottle/hr speed at which the filler currently operates. He says next year the plant plans to increase the filler speed to 72ꯠ bottles/hr, again easily handled by the multipacker. The packer brings three main benefits to the distribution operation. First, only half as many tier sheets are required per pallet: Instead of eight layers of 13 packs per layer, completed pallets consist of only four layers of 26 packs per layer. The second advantage is production flexibility. Interbrew produces both a 30-count pack as well as a 24-count with the same machine. With its single-layer multipacker, it was limited to 24 bottles. Plus, Interbrew plans to use the machine as a backup for producing 12- and 15-count single-layer packs, in case its other multipacking equipment is temporarily down. The third benefit is fast, no-tool changeover. Hutin says changeover on the new machine takes 30 minutes without tools, versus an hour and a half on the multipacker it replaced. Ultimately he hopes to reduce changeover to a mere 15 minutes. There are other benefits, too. "I think most important is that this machine is very user friendly," says Hutin. "We have a computerized control panel, a touchscreen display, on-line help and a changeover checklist [that guides operators through the process]," he says. "It's very easy for operators to learn how to change over the machine." Currently, the only change consists of switching between 24- and 30-packs. From an economics standpoint, Hutin says overall costs, including machine and material, are about the same compared to a multipacker for single-layer packs. Carton costs, when isolated, are slightly higher. Hutin is pleased with the machine's performance. "We achieve more than 90% efficiency and good reliability with this machine," he says. Not only is efficiency data graphically represented on the touchscreen display, the numerical data is transmitted automatically each day in the format of a Microsoft Excel spreadsheet directly to Hutin's office over the plant's computer network. What about the U.S.? Although the machine works extremely well for Interbrew, there are limitations when it comes to taller bottles like those we're accustomed to here in the U.S., according to Riverwood's Graham Hand, marketing manager. "You're limited to a certain height of bottle," explains Hand. "The standard U.S. longneck would be unstable in a taller pack." He explains that the shorter 25-cL bottle used for Stella Artois is a standard bottle size in France (and to a lesser extent, other parts of Europe), explaining why it made the most sense to introduce the Twin-Stack machine for bottles there. The short, 61-mm-dia bottle, "is almost like a glass can," says Hand. "It's the closest thing to a can shape in a bottle." Large-sized bottles also dampen a market's appetite for large-quantity multipacks, says Hand. "Research shows that in the U.S., 12-packs for bottles are about as large as you want to go. People aren't interested in larger packs." By way of contrast, he says France has always been a large market for multipacks in glass. "And this machine is meant for high-volume beers that sell in large multipacks." But, he points out, none of this rules out the package from making a domestic appearance. "If U.S. brewers were to introduce a shorter, fatter bottle, [then this machine] would certainly be applicable. There is a limit on bottle design, but it could be done over here. We've spoken to one or two [brewers] about it."
