As a result, flexible packaging, which can save as much as 80% in weight, has a clear advantage over rigid packaging (1).
Another source-reduction strategy includes putting concentrated products in smaller containers. Larger sizes are being embraced
by makers of laundry detergent such as Procter & Gamble (Cincinnati, OH) and Unilever United States (Englewood Cliffs, NJ), which have introduced products that wash the same number of loads with one-half or one-third of the
liquid used previously. "For packaging designers and decision makers ... the product-to-package weight ratio is an excellent
topline indicator for making decisions about packaging efficiency and sustainability," says Bob Lilienfeld, editor of The Use Less Stuff Report.
It's also possible to lighten rigid containers. The beverage industry and its packaging suppliers are using state-of-the-art
technology in process simulation, mold design, molding, and material innovations to reduce the weight of its containers and
closures without affecting its high-speed filling lines.
Nestle Waters North America (Greenwich, CT), for example, is rolling out what it claims is the lightest half-liter polyethylene terephthalate (PET) water
bottle in production ("Eco-Shape" container). At 12.5 g, the container weighs about 30% less than other water bottles. Ozarka
Natural Spring Water launched the design in August 2007, but it eventually will be used across other sizes and other Nestle
Waters brands such as Arrowhead. The lighter bottle uses a smaller label, but retains the 26.7-mm closure of its predecessor.
The lightweight container must be handled more gently, especially when empty. In some cases, it requires fine-tuning of multipack
specifications. In market tests, consumers responded positively to the container and liked it even better after they learned
it is better for the environment.
For carbonated soft drinks, Coca-Cola (Atlanta, GA) introduced an updated design for its 20-oz contour PET bottle. The design reduces container weight by 5% while
improving ergonomics with textured gripping areas. Weight savings is accomplished primarily by changes in the neck finish
to accommodate a short-skirt cap.
Container-weight reduction often goes hand in hand with closure-weight reduction. The short-skirt closures coming on the market
in the beverage industry not only weigh less than standard caps, but also allow bottle designers to use less material in the
finish area of the bottle. The combined weight savings can total as much as 2 g/container ("Xtra-Lok" mini closure for carbonated
soft drinks, "MB-Lok" mini closure for cold-filled malt beverages, Alcoa Closure Systems International, Indianapolis, IN).
Shortening the closure skirt removes material from both the closure and the neck finish of the container. (PHOTO: ALCOA CSI)
The short-skirt closures typically require changes in the capping process, but cap suppliers are prepared to assist in the
transition ("capper conversion kit," Alcoa CSI).
One way to reduce cap weight is to design the closure to stack so that the top part of one cap supports the skirt bottom of
the next. The resulting nested "logs" of closures retain their shape better. With as many as 60% more closures per corrugated
shipper, the nested closures reduce packaging, lower freight costs, and minimize the time filling-line operators spend replenishing
supplies. Currently available in 63-, 89- and 110- mm sizes, the closures are compatible with liquid and dry pharmaceuticals,
and ambient and hot filling ("TaperStack" closures, Innovative Molding, Sebastopol, CA).
Nestable design requires less material per cap plus helps closures maintain their shape. (PHOTO: INNOVATIVE MOLDING)