The following news briefs were gathered by Plastics News reporter Steve Toloken at NovaPack Americas 2004, held Jan. 26-27 in Miami.
Speakers talk risk, rewards of PP bottles
Two speakers at the NovaPack conference said they see the potential for polypropylene to be competitive with PET in bottle markets, but cautioned that improvements are needed in areas like barrier properties.
There is renewed interest in PP because advances in preform technology allow PP preforms to be made with much thinner walls, said Robert Portnoy, a senior staff applications scientist at ExxonMobil Chemical Co. in Baytown, Texas. Thinner walls mean faster cool-down and reheat times for the stretch blow molding process, and provide sufficient stretch to allow for good clarity, stiffness and impact strength, according to Portnoy.
He said many traditional disadvantages of PP, such as impact sensitivity, have been solved, but PP's poor gas barrier properties remain a challenge.
Scott Steele, a vice president of Plastic Technologies Inc. in Holland, Ohio, agreed that oxygen barrier properties remain a challenge. He said that PP has a significant cost advantage over PET at high speeds, and that economics should not hold back PP's growth.
Kosa touts material for beer markets
PET maker Kosa Inc. introduced a monolayer bottle material for beer that it claims will afford cost and performance advantages in the beer market.
Kosa, based in Houston, said its Polyshield material can make amber or green monolayer barrier bottles that don't hurt the recycling stream, and aren't as complex for bottle makers as multilayer containers, said Kevin Fogarty, president of Kosa Polymers and Intermediates.
``This product will provide the shelf life beer bottles require without the conversion head- aches,'' he said. Fogarty said the material contains an additive, but he declined to provide details.
He said the company believes its technology will be cost competitive with glass beer bottles.
``Our sense is that the limitations of wholesale conversion of glass to PET has been limited by the pure economics, [by] the ability to produce a package that competes with the economics of glass on a total system cost basis,'' he said. ``We think people will see [Kosa's system] is competitive.''
Kortec Inc. has developed a 128-cavity coinjection system designed for wide-mouth PET containers.
The Beverly, Mass.-based company said the system significantly improves the economics of putting fruit juices and other vitamin drinks in PET. The company said the system and new barrier technologies allow 8- to 16-ounce PET containers to be competitive with glass.
Kortec President Paul Swenson said previous systems were limited to 32-cavity molds. The 128-cavity system costs twice as much, but provides four times the output, he said.