Beer in Plastic: Which Structures Will Win?
A PN Staff Report
Table of Contents
Issues to Address
Coated PET
PET Plus Barrier
PET Plus Scavenger
Monolayer PEN
Monolayer PET
There seems little doubt beer in plastic is coming. In fact, it's already on the market in North America, Europe, Africa, Australia and Japan in isolated niches, particularly in venues where cans or glass are not allowed like sports stadiums and beaches.
A variety of polyester-based structures are being tested. Which one will turn out to be the favorite is the subject of considerable debate. Hurdles to be overcome include cost, shelf life, consumer acceptance, recyclability and pasteurization compatibility.
Structures currently in use include:
• Barrier-coated monolayer polyethylene terephthalate (PET)
• Multilayer PET with a barrier layer
• Multilayer PET with oxygen scavenging layer(s)
• Monolayer polyethylene naphthalate (PEN)
• Monolayer PET
Why the interest? A better question might be, 'Why not?' The beer market is huge and growing. A study by Freedonia Group Inc. (Cleveland) forecasts worldwide demand will grow to 303 billion units in 2001, up from 260 billion units in 1996. Additionally, says Bill Dando, director of Packaging Development at Bass Brewers Ltd. in England, PET bottles offer a third primary package format in addition to glass bottles and aluminum cans and can help brewers build brand portfolios.
"PET in its own right is not going to convert wine drinkers, but it is going to increase brand portfolio," insists Dando, who addressed the issue at Packaging Strategies '99 in Atlanta in March. "We have to look for new opportunities where we can seek incremental growth."
As for consumer acceptance of beer in plastic, Dando says that Bass market research shows 100% acceptance by 18-25 year olds in England. "They even prefer plastic," he adds. "They've grown up with it." In addition, plastic bottles have received "generally high acceptance" otherwise.
"We're looking at plastic as a future strategic alternative to our current packs," says Gavin Duffy, technical manager, Packaging, at South African Breweries Ltd., the world's fourth largest brewer by volume. "A third primary pack makes sense. It provides the opportunity for more customization due to the nature of its manufacturing process," he says.
Issues to Address
But there are reasons why plastic hasn't made greater inroads with beer. Beer is extremely sensitive to oxygen and light and generally needs a 120-day shelf life to accommodate the distribution chain. Few monolayer plastics can provide the barrier properties needed to achieve this. As a result, most brewers are looking at more complex structures with enhanced barrier properties, and most brands have been tested in bottles tinted amber to block ultraviolet light.
The amber tint and the assorted barrier layers/coatings have prompted concerns about recyclability and potential contamination of the PET recycling stream. Also at issue from a recycling perspective are the aluminum closures and metalized labels used on some bottles.
Since many beers — especially high-volume brands — are pasteurized in the container, heat resistance beyond what's currently possible with PET also is sought after.
Here's a review of the five plastic beer bottle structures currently in use:
Coated PET
Carlton & United Breweries (CUB), headquartered in Melbourne, Australia, is using 400-mL clear PET bottles with an epoxy-amine coating from PPG Industries (Pittsburgh) for its Carlton Cold Filtered Bitter. The Bairocade 32020 coating is sprayed on after blow molding at Amcor Ltd.'s Containers Packaging (Camberwell, Australia). Although only about 6 microns thick, the coating improves carbon dioxide and oxygen barrier properties 15 times compared to uncoated PET. The coating also can enhance clarity and gloss and/or add color.
CUB's bottle is topped with a 28-mm tamper-evident polypropylene PolyGuard closure from Crown Cork & Seal Co. Inc. (Philadelphia) with a barrier liner from Amcor. The liner consists of ethylene vinyl alcohol (EVOH) and ethylene vinyl acetate (EVA).
For recycling, the coating is removable in an optimized caustic wash, leaving a residual of less than 100 parts per million (ppm), John Mansour, business manager, corporate accounts at Amcor, reported in a presentation in February at Nova-Pack Americas '99. Resulting recyclate is acceptable for use in fiber, but since Australia has no fiber production facilities, Amcor is researching bottle-to-bottle recycling.
Acceptance of the bottle has been positive, says Mansour. "Once consumers try it, it appears they have a great desire to buy it again," he reports. As a result, CUB parent, Fosters Brewing Group Limited, has expanded usage of the bottle to include Fosters Light Ice beer.
Another coating possibility is a diamond-like carbon material, described by Akira Shirakura, manager of the packaging research lab at Japan's Kirin Brewery, this past fall at Nova-Pack Europe '98 and again at Packaging Strategies '99. Applied to the interior of the bottle by a plasma-enhanced chemical vapor deposition process, the coating reportedly adds 2 cents per container to bottle costs but improves oxygen barrier five to 10 times that of non-coated PET bottles. These bottles achieve almost the same shelf life as glass bottles, according to Shirakura.
The coated film is very thin (less than 100 nm), thus the recycling process is not a problem, says Shirakura. Only the 100 ppm of carbon will contaminate the recycled materials, and this can be easily peeled off by alkaline washing. Hydrogen content makes the film flexible enough to withstand plastic deformation.
Shirakura says Kirin is unsure when mass production of the amber colored bottles will be available. "For practical use, it may take time," he cautions.
Several continental brewers have chosen PET/nylon combinations.
A Swiss brewer, Brauerei Hürlimann AG, Zürich, plans to quintuple its production in 1999 to 800,000 coinjected five-layer bottles from Altoplast-Claropack AG, Nestal, Switzerland. The 500-mL container with a core barrier layer of a modified nylon from Ems Chemie AG, Domat/Ems, Switzerland, weighs 28 grams and provides a reported shelf life of four months.
Schmalbach-Lubeca, Rattingen, Germany, also offers a PET/nylon structure. A ½-liter size bottle is being used by Karlsberg Brauereien, Homburg/Saar, Germany, for Karlsbrau beer sold in France.
Another brewery in Switzerland is using PET/nylon 6/PET/nylon 6/PET bottles from Krones AG, Neutraubling, Germany.
Under development at Japan's Mitsui Chemicals is a copolyester called BA-030. Blended with PET, it offers barrier properties comparable to PEN. According to press reports, the material would be used in conjunction with an oxygen scavenger and UV barrier in a five-layer structure with PET forming the outer and inner skins.
PET Plus Scavenger
After testing a monolayer bottle to gauge response to the concept of plastic for beer, Miller Brewing Co. (Milwaukee) launched in November what currently is the most ambitious U.S. test of multilayer plastic beer bottles.
Miller is testing three sizes — 16-oz, 20-oz and 1/2-L — of a five-layer bottle with two oxygen scavenging layers coinjection stretch blow molded by Continental PET Technologies (Florence, KY). (Click here to see related article). Topping the container is a 38-mm roll-on aluminum tamper-evident closure with an oxygen-scavenging liner. Closures are supplied by Silgan Containers Corp. (Woodland Hills, CA) and Zapata Industries (Muskogee, OK). Metalized paper labels complete the package for Miller Lite, Icehouse and Miller Genuine Draft beers. Like its glass counterpart, the bottle for the latter is clear, while the Miller Lite and Icehouse containers are amber. Shelf life reportedly is four months.
A five-layer structure from Continental PET with dual oxygen scavenging layers also is being used by a French subsidiary of Heineken NV, Amsterdam, The Netherlands, for its Export 33 beer.
Trouble may lie ahead for this structure. In April, Crown Cork & Seal filed suit against Continental PET Technologies in U.S. District Court in Wilmington, DE, claiming the multilayer oxygen scavenging bottle structure infringes on a 1988 patent. Crown Cork & Seal wants Continental PET to quit making the bottle and is asking for damages at least equal to a reasonable royalty.
However, the Continental PET structure is not the only one currently available. In March, Anheuser-Busch (St. Louis) created a stir by launching a test market of a 16-oz three-layer amber bottle from Twinpak Inc. (Mississauga, Ontario) for cold-filtered Budweiser and Bud Light. The PET/oxygen scavenger/PET containers incorporate Amosorb 3000, an oxygen-scavenging copolyester from BP Amoco (Chicago). For added protection, the aluminum closure also features a liner with an oxygen scavenger, Darex OST, from Darex Container Products (Lexington, MA). Test markets include Circle K and 7-11 convenience stores in Dallas and Phoenix, AZ. (Click here to see related article).
Monolayer PEN
PEN is widely viewed as the ideal material for beer. It offers higher barrier properties than PET and heat resistance compatible with pasteurization temperatures. But, although its price has declined some and will probably drop more as demand increases, PEN remains significantly more expensive than PET and is not cost-effective except perhaps for refillable containers in countries where the infrastructure supports returnables. Blends of PET and PEN would reduce costs but are not currently approved for food contact by the U.S. Food and Drug Administration.
Despite the upcharge, A-B did a test last summer at New York's Madison Square Garden and marinas on nearby Long Island. The 16-oz PEN containers for Budweiser were injection stretch blowmolded by Crown Cork & Seal's Constar unit using resin from Eastman Chemical Co. (Kingsport, TN).