NEW YORK — Look out, high-impact polystyrene. There's a new rigid medical packaging plastic product on the market.
Wisconsin-based sheet extruder Pacur LLC, alongside partners Eastman Chemical Co. and specialty thermoformer Tek Pak Inc., introduced their opaque, extruded, multilayer glycol-modified PET foam to the medical packaging world in June at the MD&M East trade show.
The product, launched as an alternative to styrene-based opaque medical packaging, is the result of years of collaboration between the companies using materials already on the medical market.
Polystyrene is commonly used in medical device packaging because it can provide a reasonable amount of protection for delicate devices and withstand ethylene oxide sterilization. But an up-and-down market can cause supply chain problems for processors in addition to the usual extruding and forming issues. And HIPS is prone to cracking, which means a breached sterile barrier and possibly even a damaged device. Hospitals can be left with medical waste before a device even makes it to the operating room.
“What we were hearing from the industry was they wanted a rigid packaging material that processed better, didn't have the volatility of styrene in terms of availability and pricing and also offered features that allowed them to protect the products inside the packaging,” said Jim Banko, Pacur's vice president of sales.
The result of the collaboration is a coextruded in a three-layer product, with Eastman Eastar copolyester 6763 on the outside and Eastman's Eastalite copolyester as its core — essentially recombining materials the medical industry is already using and already ISO certified. The clear exterior layers allow the same heat seal and product contact surfaces and properties already established in the medical market while the foamed Eastalite copolyester core provides a lightweight, opaque cushion. Pacur's PETG is also cleared for sterilization via ethylene oxide or gamma irradiation.
Once the material was ready and extruded by Oshkosh, Wis.-based Pacur, there were still molding hurdles to clear. Having partnered with Tony Beyer and Tek Pak before, Pacur knew the Batavia, Ill.-based thermoformer, with 24 years of developmental tooling experience and putting out about 50 prototypes a month, could put the PETG through its paces and then some.
“All of the vagaries that anyone that's making anything in thermoforming would run into if they had a difficult-to-form package, we threw a lot of those types of design challenges into the tool. There's probably four or five different things in each area that you don't understand or see, but from a processor standpoint are difficult to form,” said Beyer, owner of Tek Pak. “So that's what we were trying to do, test how the material would form in actual production level mold on a production level machine. We really tried to challenge the material.”
Through prototype trays and mailers — featuring hinges, snap fits, undercuts and all the possible bumps and corners a customer could possibly desire — the PETG exceeded expectations, say Beyer and Banko.
“What we found is that the material, because it's flexible and more forgiving than say, styrenes, can be more easily removed from the mold, which means you can speed up the machinery,” Beyer said. “And also, because this is less weight than other full thickness materials, you put less heat into it which allows you to use less energy. And when you want to cool it to get it off the mold it requires less cooling so you can run it faster. So the material actually runs faster than styrene.”
Cuts are cleaner, too, Banko said, making Pacur's PETG a better choice for particulate-free packaging, an increasingly important decision as medical devices incorporate more and more electronic components.
“This is extremely important to us because it allows our value chain collaborators to gain efficiency in their production and even cut out some secondary processes,” said Eastman market development manager Aneta Clark. “The uniqueness of this is that we're getting completely unbiased feedback down the value chain that reinforces the message on the product.”
The companies are currently involved in “several discussions down the chain with OEMs to explore real-life opportunities” for the new PETG, Clark said.