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Milliken pushes new polypropylene applications at Chinaplas

By: Robert Grace

May 30, 2013

GUANGZHOU, CHINA — Shortly after firing an intellectual-property legal salvo at several Asian competitors, Milliken & Co. showcased a number of products and technologies at Chinaplas 2013 that focused on the sustainability benefits of its various polyolefin additives.

Shifting market dynamics — underscored by North America's abundant shale-derived natural gas supplies — also are creating new material-replacement opportunities for polypropylene for some applications traditionally dominated by polystyrene and polycarbonate, according to Wim Van de Velde, global product line manager for Milliken's plastics additives business.

Additionally, the Spartanburg, S.C.-based company said its partnership with French polypropylene producer Polychim Industrie SAS has yielded a new homopolymer PP that offers packaging thermoformers not only better aesthetics and quality but also up to 10 percent improved productivity via faster processing.

Aimed at clear and opaque applications such as food packaging, Polychim's homopolymer PP grade HA31XTF has leveraged the benefits of Milliken's nucleating agent, Hyperform HPN-600ei, to overcome the performance tradeoffs associated with the thermoforming of conventional nucleated PP homopolymers. The additive boosts transparency and reduces yellowing in the Polychim resin, and allows for both a high crystallization temperature and isotropic shrinkage behavior that avoids warpage. The resin is particularly suitable for deep-draw containers, noted Van de Velde.

The Polychim resin, however, currently is available only in Europe. Dunkerque-based Polychim, along with sister company Pinnacle Polymers LLC in Garyville, La., is part of the Beaulieu International Group. The Hyperform nucleator is available worldwide from Milliken.

Milliken also touted its Hyperform HPN-20E nucleating agent for high density polyethylene that can be used to produce a range of products, especially to counter shrinkage issues caused by pigments in close-tolerance caps and closures.

Van de Velde noted that while Milliken's Millad NX 8000 additive has been in the market for five years, the firm only recently has begun to promote its use at higher loadings to promote better clarity in clear PP containers. Previously it had touted its ability to run at lower temperatures, thereby reducing energy usage during processing.

But PP's improved pricing position vs. competitive resins is creating new opportunities, he said. Clear cup lids, for example, traditionally have been made from polystyrene, while polycarbonate has tended to be used for products such as food grinders, water pitchers and salad spinners. Now Millad NX 8000 can be used cost competitively at higher loadings in PP and can achieve the level of clarity needed in such applications.

"Wind is behind the back of polypropylene to try to capitalize," Van de Velde said.

Meantime, housewares and packaging manufacturers "expect more than excellent aesthetics and high performance from polyolefins," said Jean Hall, Milliken's plastics additives business manager. "They are looking for sustainability advantages as well," she said.

She also noted that Milliken's Hyperform HPR-803i synthetic, mineral-based reinforcing agent can reduce part weight while delivering high stiffness compared to traditional filled automotive components.

As for the series of previously reported lawsuits Milliken filed in mid-May alleging patent infringement of its Millad clarifying agents, Van de Velde said.

"We're an innovation company. We spend a significant amount of our sales on research and development," more along the lines of a pharmaceutical company than a typical chemical company, he said. The firm needs to protect that intellectual property, he said.

In the initial announcement, Milliken said only that it had "filed several lawsuits against a number of Asian companies located in a number of regions worldwide." When asked why the firm has declined so far to identify the companies targeted in the lawsuits, Van de Velde would say only that Milliken "didn't want to get into a mud fight" in the media. Instead of slinging allegations, he said, the goal is to get the activity in question to stop.

"Our customers need to be aware of this IP infringement … we are confident they do not wish to use products from companies that have engaged in patent infringement."