Most people probably twist off a bottle cap or pop open an aluminum can 10 times a day without giving it a second thought. But for beverage-makers, choosing the right closure ensures package integrity and product freshness. And today, innovations in closure technology are poised to help differentiate beverages in a crowded marketplace.

In the beverage industry, plastic twist-off caps ranging in size from 26 to 48 ml. are most commonly used with plastic bottles in which carbonated soft drinks and bottled water are packaged. Glass packaging is typically accompanied by a metal closure, such as a snap-on cap, used for beverages like beer, juice drinks and ready-to-drink teas. Virtually all beverage closures are tamper-evident; in the case of plastic twist-off caps, most are equipped with a band that breaks when the bottle is first opened.

“The preference would be passive tamper evidence, which means the consumer just turns the cap and the cap exhibits some form of security, either audible or visual,” says Sam Schiciano, global category manager, beverage closures for Toledo, Ohio-based Owens-Illinois Inc., the world’s largest manufacturer of glass containers and a leading provider of specialty closure systems. “For example, with the popping of the closure, like it would be in a glass juice container, you can hear the vacuum pop so there’s some confidence that it was the original seal.”

Beyond those basics, there are other important factors that go into choosing a beverage closure. “It depends on the process being used, whether it’s cold-fill or hot-fill,” says Roy Robinson, vice president of strategic marketing for Portola Packaging,  Batavia, Ill.-based manufacturer of plastic closures and containers for the dairy, beverage and food industries. “Obviously the seal integrity is the most important. For hot-fill, you need a hermetic seal. Otherwise, you’re running the risk of product contamination and spoilage. Mostly it’s driven by the liner technology for the closure to seal to the bottle.”

Closure liners are a principal method of sealing used in hot-fill. For cold-fill processes, a plug seal can be used, as can foil or foam liners; these are most commonly used for milk, juices or other short shelf-life drinks sold in the refrigerated case. Additionally, carbonated beverages would require a closure and liner that can retain and hold pressure.

“Most common beverage closures in the United States are two-piece, which would mean a shell and a liner. When you open the cap, you’ll see a blue liner in most soft drink packages, and that’s the second piece, which is used for package integrity and sealability,” Schiciano says. “There is a lot of work around eliminating that liner and going to a liner-less system for CSDs. That’s much more common in Europe than it is in the United States. But there’s a small number of liner-less closures being used domestically for CSDs.”

The move toward liner-less closures is rooted primarily in cost, as it requires less material and is less expensive. However, it can pose some production challenges. “A liner will seal at very low torque and very high torque. A liner-less closure needs to be put on precisely, at a much tighter range in order to get an effective seal. The liners make up for some damages in the bottle finish due to handling, and liner-less closures are not as robust in that area,”  Schiciano says. Going liner-less wouldn’t necessarily require new equipment, but it may mean tighter tolerances, more maintenance and perhaps more downtime to ensure cappers are set properly.

Cost also factors into the choice of beverage closures, particularly as prices have risen for petroleum-based plastic packaging materials. Some beverage-makers are looking into the possibility of using reduced-height bottle finishes and closures in an effort to use less material.

“Lightweighting, reduced finishes and reduced height are ways to minimize or reduce the amount of plastic used in packaging because it’s very expensive,” Schiciano says. “Costs have gone up significantly and it’s difficult to pass that on to the consumer.”

For the most part, basic closure technology has remained the same over the years, but there have been some recent shifts. “You’ve seen a switch from metal closures to plastics and that’s been driven by beverage-makers moving from glass to plastic bottles,” Robinson says. “You’re starting to see some barrier technology now. Some of the plastic beer bottles use closures that have a barrier in them, which means it’s been enhanced with a special material that will prevent oxygen ingress and/or the product leaking out through the plastic, resulting in a longer shelf life.”

Additionally, as CSD sales have slowed, beverage-makers are diversifying into other product lines, shifting the demand for certain closure types. “A lot of our business has moved from carbonated to water,” Schiciano says. “A lot of our beverage customers who used to fill CSD 100 percent of the time are now doing carbonated 70 percent of the time and purified water 30 percent of the time.”

Several new closure innovations are hitting the market in response to the need for market differentiation, particularly in functional and alternative beverages, nutraceuticals and sports drinks.

“People are looking for packaging to do more, to help sell their product,” Robinson says. “They’re looking for some kind of differentiation and things like dosing closures are part of that trend of trying to create more of an experience for the consumer at the time of purchase.”

Powercap is the dosing closure Robinson refers to, the result of a joint venture between Portola Packaging and Liquid Health Labs Inc., a Deerfield, N.H.-based company specializing in consumer goods product development. The patent-pending Powercap technology stores ingredients in liquid, powder or tablet form in a two-part closure. When the consumer turns the cap on the top of the closure, it cuts a membrane in the bottom part, releasing the stored ingredients into the beverage. The consumer shakes the beverage and it’s ready to drink. Several products using Powercap are slated to debut in early 2006.

“Enhanced beverages or vitamin waters, anything fortified is really a trend that’s moving at rapid speed,” says Liquid Health Labs President Derek Hopkins. “Powercap allows you to create an enhanced or fortified beverage without going through a hot-fill process. By storing the ingredients in dry form, or just separate from the liquid, you’re extending the shelf life. You take those active ingredients that reside in a powder form, and when dispensed into water, it creates an instant enhanced beverage that’s interactive and fresh for the consumer.”

Powercap allows beverage companies to use ingredients they normally wouldn’t due to limited solubility or shelf life; this expansion of ingredient options is critical as competition heats up in the functional beverage market.

“A good example would be a green leaf tea product,” Hopkins says. “You have little granulations of green leaf tea, and you put them in the Powercap and release them. When you mix that in with a liquid and shake it up, you can see those granulations floating in there. On an immediate-consumption basis, because the consumer perceives that as fresh, they could quite possible drink that and be okay with it. But if you made that same product as an RTD product, when you picked it up off the shelf, all the green tea leaves would be down at the bottom as residue. People are going to see that as old, not fresh, and not really appealing.”

Under their partnership, Portola provides Powercap’s two pieces of injection-molded plastic, and Liquid Health Labs fills it with ingredients and assembles it to bring Powercap to a finished state. Powercap can be customized to beverage companies’ desired neck thread sizes and ingredient load capacities.

“The biggest key is to get these technologies to market and commercialize them,” Hopkins says. “We have a solid partnership that fills all the roles to deliver the finished good. That’s really what beverage companies are looking for. They’re not looking to get into the closure business or the filling business or even in many cases the R&D process. We’ve put together a value-added offering through this partnership to deliver a finished good.”

Another new product, while not a closure per se, depends on closure technology to dispense ingredients. Defense Vitamin & Mineral Supplement, from the New York beverage development and marketing company Brain Twist Inc., uses the FreshCan Wedge, a technology created by Degussa FreshTech Beverages and Ball Corp.

The FreshCan Wedge is similar to Powercap in that it keeps vitamins and minerals separate from a beverage until it’s ready for consumption. In FreshCan’s case, powdered vitamins and minerals are stored in a recyclable plastic wedge that floats inside an aluminum beverage can. When the consumer pulls the tab, nitrogen escapes from the can and the wedge’s top pops off, releasing the vitamins and minerals into the beverage.

“The big issue is vitamin degradation — are you really getting what’s advertised on the label — because water, time, light and processing all affect the strength of the vitamins and minerals,” says Brain Twist President and Chief Executive Officer Larry Trachtenbroit. “With this new FreshCan technology, it doesn’t matter if you’re opening the first can or the one millionth can. You’re getting exactly what’s printed on the label because at that time, you’re activating the wedge to release the vitamins and minerals into the beverage.” BI