Plastic caps, tubes and closures maker Essel Propack Ltd. said it may be on the verge of the next big breakthrough in bio-based packaging applications.
The Mumbai, India-based firm, which operates two plants in Danville, Va., recently tested several grades and additives of polylactic acid with success.
A customer of ours is interested in some closures, to see if we can get some green compostable or reusable PLA in our caps, Kerry Dodds, the Danville molding plant manager, said in a June 4 telephone interview. He would not name the client.
Essel's testing was done in a laboratory at Danville Community College, which counts the company as a supporter of its associate degree programs in polymers manufacturing technology, and advanced manufacturing engineering technology.
According to Dodds, the lab has a selective laser-sintering prototyping machine, as well as an extruder, an injection molding machine and several other pieces of equipment.
College officials were unavailable for comment.
Ten years ago, PLA was brittle, hard to process and experimental, Dodd noted. Today, it is gaining wider acceptance in the plastics industry for bottles, disposable cutlery, foam and other packaging applications.
I'm testing batches [of PLA] on a roughly 24-hour cycle, he said. We're finding that as far as strength goes, PLA performs as well as, and possibly better than, standard injection-grade polypropylene. Sinks were the most common defect, he said.
According to Dodds, four of the 14 samples batches of PLA resin recently tested ran as expected in the closure mold. The samples consisted of hybrids of PLA and PP, PLA color and a 4-5 percent impact modifier. The hybrid blends performed like standard injection-grade polyolefins, he said.
If tests continue to be successful, Essel will market the PLA closures later this year, Dodds said.
Essel Propack is part of the $2.4 billion Essel Group. Essel Propack's annual sales are about $300 million. The company claims a 32 percent share of the laminated tubes market. It operates 25 plants in 13 countries in the Americas, Asia and Europe. It employs 2,700.
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