The lightweight 500-ml nonreturnable bottle launched a revolution in the bottled water industry, but it posed an intriguing challenge for bottled water manufacturers.
The Packaging Challenge
Over the past 10 years, 500-ml PET mineral water bottle weights have fallen from 25 grams to 9 grams, creating more compressible, environmentally friendly and less expensive bottles. Polyethylene shrink film multipacks, now the industry standard, have been getting larger and heavier, often requiring corrugated trays or pads for package stability, which in turn has added cost and introduced a recycling and carbon footprint negative.
The Offset Solution
Offset, or staggered, packages solve this riddle. In offset packaging, alternate bottle lanes are advanced one-half-bottle diameter in relation to each other in a Hartness GlobalShrink machine.
This creates a honeycomb pattern which results in six contact points between bottles, instead of four, which is typical in a standard rectangular pack. This grid allows greater shrink force between the rows of bottles when the package is tightened. This greatly reduces the bottles’ tendency to move laterally within the package, leading to consistently tight, great-looking, and, most importantly, safe packages. “Offset packaging is a unique value proposition,” says John Loughlin, Hartness market development manager for film products.
Tested and Proven
To confirm that the offset package was stronger and more stable, the Hartness GlobalShrink team and Hartness Robotic Palletizing engineers visited the Clemson University Center for Flexible Packaging (CEFPACK) with a number of bottled water customers. Offset multipacks were packed on Hartness GlobalShrink high-speed shrinkwrap machines. The packs were then palletized and run through a series of ISTA-3 pallet tests, including random steel vibration, compression, incline impact and a specially designed corner-drop test. The tests included packages of 24, 28, 32, 35 and 40 lightweight PET bottles.
The results were unmistakable. Offset packages were tighter than the traditional packages and had increased pallet stability. “For some package sizes, it’s possible to palletize one more pack per layer per pallet,” Loughlin says. That means fewer transport trucks. The increased stability and strength of the package eliminates the need for corrugated cardboard to stabilize large water multipacks, making the package more environmentally friendly, and, in some cases, allowing Hartness customers to double stack pallets in the warehouse, saving valuable warehouse space.
Pallet stability test at Clemson University
Hartness engineers made one more key finding: Bottles in the offset packages stayed tightly packed even after a progressively greater number of bottles were removed from the package. “The packages look better on the store shelf because of their increased tightness, which increases the customer’s chances of selling all the packages on the shelf,” Loughlin says. The tighter package conferred another advantage: Workers can carry the remaining packaged bottles safely as they load refrigerators, vending machines, or other storage locations.
John Loughin tests offset pack handling as bottles are removed from package. http://youtu.be/7tpMrROoy8g
“The increased package strength leads to safety and increased pallet stability, while the stronger package gives a more attractive on-shelf appearance,” says Loughlin. It’s a stronger, smaller package that makes storage safer, use easier, and distribution more efficient. The reduced cost from eliminating the corrugated cardboard is just the cherry on top.