Papers at Nova-Pack Europe 2004, held Oct. 18-19 in Neuss, Germany, covered recycling, China, barrier layers for PET, and new manufacturing methods. Plastics News senior reporter Bill Bregar gathered the following items at the conference.
Study: Beer requires sensitive packaging
``Beer is the most sensitive beverage,'' said Martin Orzinski, assistant laboratory manager at the Research and Teaching Institute for Brewing in Berlin, and you can believe him - the VLB institute was founded in 1881.
Orzinski explained how VLB, the Versuchs und Lehranstalt fur Brauerei, is testing plastic beer bottles. One conclusion: One-piece plastic caps can allow too much permeation of oxygen and carbon dioxide. Nicht so gut. Two-piece caps with an oxygen scavenger are much better.
Orzinski called the closure ``the biggest hole in the packaging.''
Also, VLB research shows that after six months, three-layer plastic beer bottles with an oxygen-scavenger closure perform better than a glass bottle with a standard crown cork for oxygen permeation. The two materials performed nearly the same for carbon dioxide, Orzinski said.
China's move to virgin resin may impact U.S.
China buys one-third of all U.S. recycled PET bottles and flake right now, but that could fall off as China expands its virgin PET resin and its domestic recycling infrastructure, according to Patty Moore of Moore Recycling Associates Inc. of Sonoma, Calif.
``You could have a combination of there being a possible oversupply of virgin and China having their own supply of low-cost recycled material, and you could have one potential scenario where China shuts its doors to our PET,'' Moore said.
If that happens, and the United States and Europe do not have enough reclamation capacity to handle all the PET collected, then the system could collapse, she said. That could lead to costly producer-responsibility laws, she said.
The bad-case scenario is at least a year away. Prices for virgin PET and PET bales should be firm through 2005, since feedstock chemicals are in short supply, according to Moore. But China has a massive construction of new polyester capacity that will come on line in 2006, she said.
Moore said some observers think China could even become a new exporter of polyester in a few years.
Citing figures from the National Association for PET Containers Resources in Charlotte, N.C., she said China consumed 300 million pounds of PET bottles and flake in 2003, or 35.5 percent of the U.S. total.
``The Chinese are definitely taking substantial amounts of material,'' Moore said, adding that more than half of it goes into fiber.
China has a particularly big impact on the West Coast, Moore said, because it is much cheaper to ship recycled PET from California to China than to transport it from the East Coast.
Moore said the PET industry should work with China and other Asian nations to improve environmental and labor laws, which would help U.S. and European reclaimers get on an even footing with Asian firms.
Double dipping boosts PET barrier properties
A dip-coating method, called PetSkin, gives barrier properties to PET containers, said Roberta Pesce, technical manager at the year-old Italian firm Plastlac srl.
PetSkin increases carbon-dioxide and oxygen barrier properties of PET, with no danger of delamination, she said.
The process uses two coatings. The first coating, applied by dipping, is the base, or barrier, coat. After the base coat cures, the container is dipped again, into a topcoat, which increases the barrier and protects the base coat. A shot of ultraviolet radiation cures the second coat.
Between the two coatings, the container is heated in an oven, so water and solvent evaporate. The coating undergoes photo-cross-linking from the UV radiation, said Plastlac of Alessandria, Italy.
The entire process takes about one minute, but Pesce said the company is researching ways to cut the curing time.