Zed Develops Thermoforming in a Vacuum

Peter Zelnick can imagine Zed Industries Inc.’s new thermoforming machine — which forms parts in a vacuum — turning out panels for buildings on Mars.

How about something more down-to-Earth?

• Medical parts thermoformed from exotic new materials.

• Multi-layer parts where the layers require different softening-point temperatures, evacuating all trapped air bubbles.

• Accelerated age testing in a laboratory.

• Optics and touch-screen electronics.

Zed Industries calls the new lab machine the Model L-3MA thermoformer. The MA stands for modified atmosphere.

Zelnick said thermoforming in a vacuum uses a fraction of the energy of traditional forming, which has to heat the air. In fact, he said that in most thermoforming machines, a good portion of the heating in most thermoforming ovens comes from hot air transmitting the heat to the sheet, in a convection process.

So Zed got rid of the air, removing the variable of gas that has to be heated.

The L-3MA heats the plastic sheet directly, through infrared radiation. “There isn’t any air to mess up the whole process, to absorb the energy. It’s going straight into the plastic,” he said.

Zelnick explained the technology — and motivation — behind thermoforming in a vacuum during an interview at Zed Industries in Vandalia, north of Dayton, where he is CEO. The innovation technology came about, like many other Zed breakthroughs, to help a customer solve a problem.

Zed already offered a standard, lab-sized L-3. “A client came in and he had an application where he had to heat and form unique materials. And in one case he wanted to form two and three layers of film at the same time. However, the two outer layers processed at a lower temperature than the inner layer,” he said. The temperature spread was wide.

“The inside material had a 150-plus-degree difference in softening point than the two outer materials. So you can’t just heat that with a conventional convection in a radiant oven,” he said.

Zelnick declined to identify the customer or the application. But the controlled-atmosphere process made good parts from the dissimilar materials, he said. Also, the vacuum sucks out air that otherwise could become trapped between layers and form unwanted bubbles.

The initial Model L-3MA is a shuttle machine. “You load the sheet up, close the door, and it takes about a minute to pump the chamber down. The heaters come up to the temperature that you want to run at. You can change the wavelength coming off the face of the heater, knowing what absorption temperature the resin best absorbs infrared in,” Zelnick said. He added that Zed Industries has learned a lot about fine-tuning an IR heating element by developing the new machine.

Now, Zed engineers are working on an inline version of the machine. Used in production, a continuous inline MA thermoformer would exploit the technology’s lower energy needs. Zelnick said the trend toward “green” manufacturing by reducing carbon footprint could make the MA process attractive for traditional parts.

The vacuum also pulls any gases out of the part, in effect speeding up the process of off-gassing, to test new materials. “You can age-study that plastic now, because you’re accelerating the loss of the plasticizer within the resin while you’re forming it,” Zelnick said. “So if I want to do age-testing studies, vacuum does more than save me money, it lets me see the actual aging on the sheet while I’m forming it.”

Zed’s thermoforming and packaging machines include form-fill-seal machines, blister sealers, clamshell sealers, medical sealers, skin packers and die-cutting presses.

Today, Zed Industries is run by the Zelnick brothers: Peter is CEO; Mark is president.

The chairman is David Zelnick, their father and a thermoforming pioneer. In the 1950s, selling plastic film for U.S. Rubber Co., he built a small vacuum former using an old freezer compressor and a used oven-heating element. Customers began asking about the machine, and so in 1954, Zelnick and some partners founded Atlas Vac Machine Corp. in Rochester, N.Y.

Peter Zelnick said his father became Kodak Co.’s go-to guy for form-fill-seal and thermoforming machines. He served as Atlas Vac Machine’s president until 1964, then spent four years as general manager.

In 1969, David Zelnick and his wife, Helen, founded Zed Industries in Vandalia. One early machine — for packaging pharmaceutical pills in push-through foil — showed how he sometimes was ahead of his time.

“Everybody looked at that and said, ‘Whoa, nobody wants to push those meds through that little foil thing. That’s crazy! The pharmacist counts those out.’ Everybody pooh-poohed it,” Peter Zelnick said.

The first machine still is running today, in Arizona, producing kids’ makeup kits for Halloween, he said.

“We built machines with less linkage, less moving parts, less to wear out. And everything on a Zed you can buy, for the most part, off the shelf,” Zelnick said.

Zed’s chain drive has endured. Packaging thermoforming machines use a spike-like chain that pulls the plastic sheet through the forming area. Conventional chains can wear out and need frequent replacement, as the metal links ride on metal rails, he said.

The Zed chain lasts a long time because it is a doublewide pin chain that rides on steel-hardened chain track with cooling lines machined inside. The circulating coolant keeps the track from expanding through heat from the high-speed moving chain, which can throw off the correct indexing.

Zed Industries remains family owned.

Mark Zelnick attended the University of Utah, where he earned a bachelor’s degree in materials science engineering a master’s of science in metallurgical engineering. He became Zed’s vice president of production, then president in 2003, when the brothers bought the business from their father.

Peter Zelnick has a bachelor’s degree in chemistry, ecology and evolutionary biology from the University of Arizona. He worked at aerospace at defense manufacturer McDonnell Douglas, becoming manager of the non-metallic, insulation, adhesives and polymer laboratories. He returned to the family business, and became CEO in 2003.

In his McDonnell Douglas days, Peter Zelnick dreamed of thermoforming in outer space — the ultimate vacuum. He even wrote a paper on the subject. Zed’s press release calls the L-3MA “a landmark system in the move to take thermoforming technology out of this world” in a future of “thermoforming resin into sheet and ultimately pressure forming structures in space and other non-Earth environments.”

It sounds like something out of The Martian Chronicles.

He elaborated that one day, space explorers could create their own raw material on a planet that has natural gas and carbon dioxide, as precursor ingredients. Solar power would provide an unlimited energy source.

Then you would need a thermoforming machine — a Zed — to form it into building panels.

Published: December 27, 2012

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