PACK EXPO Las Vegas: PLA rises to a starring role

Gilbreth can print its iridescent-ink shrink sleeves on PLA.

Sustainability in packaging, which is on everyone's mind and on many people's lips, is an enormous topic. It encompasses not only the obvious challenge of how to dispose of used packaging, but also the many less overt but equally important questions about energy needs, costs, what qualities might be compromised to achieve sustainability, and whether the pressure to get to market with new materials might not leave adequate time to confirm how they will perform over the long term.

The following story is the first of a four-part series on sustainable packaging materials and equipment featuring products to be exhibited at PACK EXPO Las Vegas 2007, Oct. 15 to 17 at the Las Vegas Convention Center.

Sponsored and produced by the Packaging Machinery Manufacturers Institute (PMMI [www.pmmi.org]), the show has always been a forum for packaging professionals to learn about—and debate—the latest industry trends. This year will be no different.

There has been a great deal of talk about packaging produced from a corn-derived biopolymer called polylactic acid or polylactide (PLA), considered by some as a great step forward in the march toward environmental sustainability in packaging materials. Some packagers are already using it in film or rigid forms. So, now that it has been out on the market for a while, what's the verdict?

PLA packaging material has its fans, not a few skeptics and a larger number of people standing on the sidelines before jumping in, waiting to see how it will perform in the face of challenges during this "shakedown" period. Early informal assessments included reservations about manufacturer NatureWorks' (www.natureworksllc.com) ability to produce the material in sufficient volume, PLA's ability to remain shelf stable over time, etc. Time has resolved some of those issues, but not all. The slow growth in commercial use of PLA, for instance, has meant a gradual growth of demand, and that seems to have alleviated the concern about supply. Stability is still being debated.

Ameri-Seal supplies PETG printed shrink sleeves for Swanky Girls' indoor tanning lotions.

To learn how BLUE LAKE CITRUS PRODUCTS, Winter Haven, FL, uses PLA for its Noble Organics juices, see www.packagingdigest.com/ info/noble07

It is also important to remember that while reasonable people acknowledge that there is no perfect product and no perfect solution to any challenge, when the rise or fall of manufacturers of packaging materials and the reputations of companies that use them are potentially at stake, scrutiny is bound to be hard.

Theresa Sykes, product development manager of Gilbreth Packaging Systems (Booth C-4724), is one of the fans of PLA. And her company is a regular user of PLA film in its shrink sleeves, many of which will be on display at PACK EXPO Las Vegas. The company promotes its use of PLA film on its website.

Sykes' enthusiasm stems from what she views as the material's multiple positive attributes. First of all, PLA is compostable, which means that it won't degrade in landfills. True, for efficient composting, it needs to go to commercial composting sites (of which there are currently about 4,500 in the U.S., according to Modern Plastics Magazine), but even in the compost pile behind your barn, it will decay, though it will take longer. It can also be safely incinerated.

Second, PLA film shrinks at a lower temperature (as much as 40 deg F lower), which reduces fuel requirements and therefore emissions, and raises sleeve productivity.

Third, there don't seem to be any "giveaways" to gain these benefits when using PLA films. It prints beautifully, though special inks are recommended (for compostability, not print quality). For instance, Gilbreth even can print its popular Rub 'N Smell and iridescent-ink shrink sleeves on PLA. It shrinks as well as films made from polyvinyl chloride, polyethylene terephthalate glycol and oriented polystyrene.

In a different application, Polypack, Inc. (Booth C-1135) has developed the Ecobundler, the world's first shrink wrapper built specifically for use with PLA film. The company worked closely in collaboration with the makers and distributors of PLA film to refine the biodegradable shrink film so that it would work smoothly with the new high-speed wrapper.

The Ecobundler is a high-speed system that provides registered print wraps for multipacking at speeds of up to 60 wraps/min (single lane) or 120 wraps/min (dual lanes) for any configuration of bottles, boxes and odd shapes. The automatic machine is also able to wrap using other materials, including polyethylene, polypropylene and PVC films.

Todd Wright of Silgan Plastics Corp. (Booth S-5417) sees both the positive and negative sides of the PLA evaluation. He is very positive about labels and shrink sleeves made of PLA film, but Silgan makes rigid plastic products—from bottles and jars to closures—and the company's evaluation of resins for this use have been less than positive.

Winterborne's EnviroShell offers a different approach to sustainable packaging by surrounding an RPET blister with corrugated.

The problems include the material's temperature sensitivity and long-term permeability for water-based products. "It has proved practical for making food-packaging clamshells that hold products that will be transported and held in a controlled cold-chain environment," Wright says. "It seems to work very well for salad ingredients and for packaged fruits and veggies.

"I definitely feel PLA is a step in the right direction. When the issues with compatibility and contamination of the PET recycling stream are resolved, more conversions will occur. We continue to evaluate the material and are always committed to more environmentally friendly practices/resins to serve our customers."

It also works well for Naturally Iowa's PLA milk bottle, which, barring an emergency, will remain in cool- temperature environments throughout its trip from the dairy to the consumer.

The problem comes when that cold chain is not ensured. Rigid packaging that will not be temperature-monitored and might end up spending time in an unrefrigerated trailer truck or warehouse in a warm climate will begin to deteriorate.

Manufacturer and converter Ameri-Seal, Inc. (Booth S-5835) does convert PLA film for its customers, but president Howard Millstein indicates that many companies using shrink sleeves are still leery of this film because it's not proven to be completely stable due to its corn base and because it seems to exhibit different shrink characteristics than traditional plastics.

"That is our main concern," he says. "Distortion of graphics is critical when the sleeves shrink onto a container."

SleeveCo produces PETG shrink sleeves for customers, including the label on Schultz's All Purpose Plant Food.

When considering form/fill/seal pouches, Fran Ventura, vp of sales for Ossid Corp., a division of Pro Mach Corp. (Booth C-709, -711, -723) and a maker of f/f/s equipment, has a different perspective. He points out that PLA is thermoformable and therefore can run on automated machinery. That, plus the support of clubstores committed to achieving sustainability in their packaging, will drive PLA's development, he says.

"We have worked with a customer doing preliminary work to make horizontal form/fill/seal pouches of PLA," he adds. "There are some challenges: It doesn't cut as cleanly as traditional plastic films, for instance, and we found that heat across the surface was not always uniform. There were hot spots and cold spots. No doubt it will take some time, but we will get there."

The plastics that compete with PLA, both in film and in rigid applications, are PETG and recycled PETG (RPETG), PVC and OPS. Each has its advantages. PVC is cheap and easy to use, but it continues to raise controversial pollution issues since it emits small amounts of vinyl chloride monomer, a carcinogen, during compounding. OPS is very popular in Asia, partly because it is less expensive than PETG and because, as a shrink film, it performs very smoothly. But it too is temperature-sensitive and has to be shipped in a controlled environment. And, OPS and PET are not without their environmental concerns in terms of acidification, eutrophication and photochemical oxidation.

Recycled PET (RPET), PETG and RPETG are the real competition. Howard Millstein of Ameri-Seal estimates that PETG accounts for 70 percent of his company's conversions. RPETG offers the added advantage of incorporating recycled material, which has made it a favorite with clubstores and, by extension, their suppliers. The EnviroShell™ package developed by Winterborne, Inc. (www.winterborne.com) and its strategic partner Smurfit-Stone Container Corp. (Booth C-2423), for instance, combines a "sandwich" of corrugated surrounding an RPET blister that creates a package that is reportedly 65-percent recyclable, including 50-percent post-consumer waste and the 100-percent-recyclable RPET.

SleeveCo (Booth S-5604), which has also been a user of PLA almost from its introduction to the marketplace, produces more PETG than PLA shrink sleeves for customers and has won a number of awards for the quality of those sleeves, including a gold award from the International Gallery of Superb Printing.

Currently, the traditional plastics still dominate the packaging marketplace in terms of volume, but PETG and RPETG are moving up quickly. And where does that leave PLA in the race toward environmentally sustainable packaging? This question is the object of a great deal of scrutiny and not a little speculation.

For more information about PACK EXPO Las Vegas 2007, visit www.packexpo.com or contact PMMI's Show Department at 703/243-8555; fax: 703/243-8556; or e-mail [email protected]).

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