Engel’s Medical Days drew 123 attendees to the machinery supplier’s US headquarters 15-16 June.

Engel ran three demonstration machines, including one showing the first-ever use of its X-Melt technology running liquid silicone rubber. Joachim Kragl, director of advanced moulding systems and processing, dubbed the demonstration “truly a world premier”. The e-Victory press moulded a tiny check valve for controlling medical fluids. Each part weighed just 0.03 gram.

With X-Melt, the screw builds up a high melt pressure with the shut-off nozzle in the closed position. For injection, the nozzle opens up and allows the melt to shoot into the mould all at once. “You can get extremely fast-fill, thin-wall parts,” Kragl said. “It’s really a perfect process for small parts and micromoulding.”

Since the entire mould is filled at full melt temperature, the material picks up all details of the mould, he said.

Using X-Melt for micromoulding allows for a larger-tonnage machine for a high degree of precision. Kragl said the machine can do 10 microshots before the screw needs to recover more material, providing accurate dosing.

The e-Victory machine was equipped with the hybrid Ecodrive, which marries an all-electric injection unit with a servo-driven hydraulic pump to run the platen movement. The pump runs only when needed and reduces heat loss into the clean room.

Christoph Lhota, vice president of the medical business unit at Engel Austria GmbH, explained how the Schwertberg, Austria-based injection press maker dedicated a team to medical moulding five years ago.

A fast machine is important, since many medical parts have long cores. All-electric presses have become the most popular medical machine, he said.

“Our choice was, we took the clamping technology from our packaging machine and electrified it,” Lohta said. Since then, Engel has built about 300 medical presses a year.

Steve Broadbent, process engineer of Engel’s liquid silicone rubber and elastomer machinery, reviewed several LSR applications including a seal ring for a dialysis filter, a silicone valve for needle-free coupling of ports and a face mask for sleep-apnea patients.

“We all know the problems hospitals are having now, where patients come out with infections, Broadbent said. “So LSR gives you the ability to make a disposable, single-use product.”

Keeping the process clean is critical, speakers said. Lohta noted that Engel’s research shows that the injection press itself — whether hydraulic, hybrid or all-electric — has a low impact on particle-count contamination in a clean room.

However, contamination does result from purging material out of the press. Engel uses barrel exhaust to remove both heat and contamination during purging. For mould changes, rollers can be incorporated on the platens, so moulds roll in and out.

Engel links full process documentation, required for medical moulding, for the press and all automation, which is run through the machine controller, Lohta said.

Automation plays a key role in medical moulding, both to ensure quality and keep the process clean, speakers said at Medical Days.

“The greatest source of contamination is the people inside the clean room,” said Morgan Polen, vice president of application technology at Lighthouse Worldwide Solutions, a Fremont, Calif.-based maker of contamination monitoring systems.

Attendees in York heard from representatives of automation specialists Hekuma Automation and Waldorf Technik. A high-speed Hekuma side-entry robot removed petri dish tops and bottoms from a 16-cavity mould on an Engel e-motion press, assembled them together, stacked them and, finally, enclosed them in a plastic bag.

Automation systems can be designed specially for clean rooms, said Hekuma Automation President Mike Walper. That includes covering and sealing off any moving parts, using low-abrasion cables and hoses and using smooth, round corners, which are easier to wipe clean than sharp corners.

Robert Herman, sales manager of Engel’s medical business unit, said drives and bearings are encapsulated on the petri dish cell. “They’re all enclosed so there’s no potential for contamination from moving parts,” he said.

At the York event, Waldorf Technik supplied full automation for an Engel e-max moulding pipettes on a 32-cavity mould. The system included 100% vision inspection with a six-axis articulating robot removing the parts and presenting them to a camera mounted into the moulding cell.

Waldorf Technik’s business development manager, Lisa Mauro, said in-line automation is better than offline — where parts free-fall out of the mould and then have to be properly aligned for downstream work. In-line automation can provide cavity separation, which is important in medical for part traceability. Vision inspection gives real-time feedback.

“Downstream is not the time you want to find out that cavity eight is having problems,” Mauro said.

Parts can be automatically assembled, and bagged by cavity or loaded into a box or a tray. “That’s the bottom line of in-line automation — removing the risks associated with the moulding process,” she said.

People who attended Engel’s Medical Days also learned about a metal alloy and a technology to combat counterfeiters.

Thomas Steipp, president and CEO of Liquidmetal Technologies held up a metal replacement knee joint made from the material. Liquid metal is 2½ times stronger than titanium, he said. Like plastic, it does not shrink when processed. “We can get machined-like parts out of the mould,” he said.

Liquidmetal has partnered with Engel to target precision-machined parts, at dramatically lower costs, Steipp said. The company has installed two Engel injection presses at its headquarters, retrofitted to make the metal parts. Steipp said Liquidmetal and Engel are working to make machines for higher-volume production.

Meanwhile, Liquidmetal made news earlier this year by signing a licensing agreement with watchmaker Swatch Group.

Michael Flemmens gave a sobering presentation on counterfeiting artists, who he said often work out of China, India and the Middle East. “They will knock off anything,” said the technology manager for ARmark Authentication Technologies.

He described ARmark’s “covert markers” — tiny, coin-shaped discs about the size of a human hair imprinted with a company logo, lot codes, special colours and/or text. The markers can be viewed under a microscope.

One application is to identify blister packs on drugs, and there are edible grades that can go directly onto the pills. The markers can be injection moulded.

“The second you mould it, it can be tracked,” Flemmens said.