Plastipak Packaging Inc.'s new PET bottle technology relies on a marriage of extrusion and injection molding in the preform production stage, according to a Plastipak official. The Plymouth, Mich., firm claims its Exxi-Pak technology allows cost-savings and added value in PET containers. It can achieve very thin middle barrier layers, reducing the need for expensive barrier resins. Exxi-Pak bottles can contain a post-consumer outside PET layer and such constructions recently received ``no objection'' status from the U.S. Food and Drug Administration for use in food containers.
Ron Overbeck, Plastipak's vice president of sales and marketing, simplified the Exxi-Pak process as precise extrusion of a shell and then injection molding over it to form a preform. In a telephone interview, Overbeck said his company used its experience in extrusion blow molding to develop the process in a research program that took more than three years.
Plastipak has a demonstration Exxi-Pak system at Husky Injection Molding System Ltd.'s advanced manufacturing center in Bolton, Ontario. Husky provided systems integration and injection molding and parts handling technology, a spokesman in Bolton said. The Exxi-Pak system has been operational there since the second quarter. A Husky spokes-man said Exxi-Pak will open ``new opportunities for the container industry.''
Plastipak will exhibit Exxi-Pak bottles at the InterBev '96 trade show in Houston on Nov. 18-20. The multilayer technology will allow plastics to replace glass and other materials in many applications, it claimed.
Overbeck said Plastipak has not targeted a specific market but will promote Exxi-Pak where ``it brings value.'' Ability to vary the barrier layer and make it thinner than normal injection limits will be a major selling point.
Overbeck said his firm has tried various conventional barriers, including ethylene vinyl alcohol and nylon, and has made bottles with 80 percent post- consumer PET content and with new polyethylene naphthalates.
Plastipak claims Exxi-Pak can be used in the highest cavitation PET molds now being run. Bottle layers and thicknesses are changed easily, it said. The process has three online checking steps for each layer and for container quality.
A processor also can cut pigment costs by coloring only one layer. There are no tie layers, so bottles delaminate when ground, making it easier to recycle flash, waste and post-consumer bottles.
Plastipak holds licensing rights in North America and may license it `'in the near future.'' Overbeck said Plastipak and Husky will jointly hold licensing rights elsewhere, but a Husky spokesman would not comment on the rights. Both firms hold patents for the process.