Farmingdale, NY-based label converter Seal-It, Inc., is on the “husk,” as it were, of the hottest advancement in the shrink-film label market. Since February, Seal-It has been offering its customers shrink-sleeve labels (shown above) made from a film based on renewable resources that has proven to be competitive in both characteristics and cost with most traditional, petroleum-based films.

The transverse-direction-oriented (TDO) polymer, called EarthFirst® PLA TDO, is made from corn-based polylactide resin engineered by NatureWorks LLC (www.natureworksllc.com). Via considerable research and development by film provider Plastic Suppliers, Inc. (www.plasticsuppliers.com), EarthFirst PLA TDO is the first commercially viable shrink film made from NatureWorks PLA to enter the market.

“I really believe that this is the film of the future,” says Seal-It president Sharon Lobel. “While we shouldn’t disregard the other films, because they all have their place depending upon the application, PLA is the new kid on the block now, and everybody wants to get to market with it first.”

Initially, one of the barriers to PLA adoption was its high price relative to petroleum-based films. In 2002, NatureWorks (then Cargill Dow) christened its first large-scale production facility in Blair, NE, to manufacture PLC—half of which was slated for packaging applications. This increased capacity, coupled with a petroleum market besieged by volatile pricing, helped to bring the cost down to a more palatable level for potential converters and end-users.

A perfect fit for Plastic Suppliers—a producer of biaxially-oriented polystyrene—PLA lends itself well to the company’s existing manufacturing processes, says Rich Eichfeld, vice president of business development at Plastic Suppliers. At its plant in Columbus, OH, the filmmaker has engineered EarthFirst PLA film for folding-carton windows, bag windows, bag laminations, container lidding, twist wraps and floral wraps, as well as shrink film.

As Eichfeld relates, the biggest challenge to adapting PLA film for these applications has been the rigidity of the film. “One-hundred percent PLA has limitations,” he explains. “It’s a very brittle product. The way we addressed this problem was through different additives and manufacturing processes.”

It took Plastic Suppliers about one year to engineer a PLA film suitable for shrink-sleeve label use. Eichfeld says the company drew upon its expertise in making its Polyflex® TMOPS preferentially oriented PS shrink film, as well as input from co-branding partners like Seal-It. “We were able to make proper adjustments to the film to meet Seal-It’s concerns,” he says. “Then we would allow them to look at the film and give us their feedback, and we kept refining as we went along.”

Operating 150,000 sq ft of manufacturing space, Seal-It has provided label printing and converting services for 20 years. With a focus on heat-shrinkable labels, the company works with a variety of substrates, including PVC, PETG and OPS to convert full-body shrink-sleeve labels, tamper-evident neckbands, multipack wrappers and more. Its services include in-house design and prepress, as well as modified flexographic printing, gravure printing and label seaming. Seal-It’s newest equipment is a 40-in., 10-color gravure press from a proprietary supplier.

Seal-It tested EarthFirst PLA TDO film on its converting equipment during the material’s development phase. Says Lobel, “Some other converters may just be starting now; it will take them a while to learn how it handles. Even though the final product looks pretty much the same [as labels made with petroleum-based films], the converting and handling of the film is very different. It takes time to learn how to work with PLA.”

EarthFirst PLA TDO, available in 2- and 2.4-mil thicknesses, is scuff-resistant, compliant to US Food and Drug Administration standards, and offers up to a 75 percent shrink in the transverse direction. According to Lobel, only PETG has a higher shrink rate—at 80 percent. As for printability, EarthFirst PLA TDO is said to be compatible with all traditional printing processes, as long as converters learn how to adjust the tension control to accommodate the new material.

As Lobel explains, part of Seal-It’s learning curve with the new film was to test it on every piece of equipment needed to produce a shrink-film label. “We had to look at the printability to make sure that the colors were vivid and bright,” she says. “We looked at our slitting equipment and said, 'How do we have to change the process to accommodate PLA? Do we need different blades?’ We looked at the seaming process to see if there were any differences there, and so on.”

Regarding cost, PLA is now gaining a favorable footing because of the stability of maize prices versus petroleum-based polymers. Says Eichfeld, “It’s not the least-expensive product on the market; that would be PVC. But PLA can compete with most shrink films.”

Lobel concurs. “The cost for PLA is better now than it used to be. If you rate the cost of the four films—PVC, PLA, PETG and OPS—I’d put PLA somewhere in the middle.”

Machinability and cost concerns aside, PLA’s desirability also lies in its natural, renewable origins, and that products made from it can be disposed of through composting.

While Seal-It cannot yet disclose any of its customers pioneering the use of shrink-film labels made from EarthFirst PLA TDO, Lobel says that “everybody wants to do it first,” especially the larger customers. And she adds that, while stores such as Wal-Mart have given PLA a big push, that was not the driver behind Seal-It’s adoption of the material. “It’s exciting to offer a film that has no dependency on oil and is totally home-grown.”

This article originally appeared in Packaging Digest (Sept. 2006).