Medical molding: to save money, think outside the cleanroom box

Cleanroom molding is an expensive, but necessary, proposition for many medical applications. However, there are ways to rein in some of those expenses, according to Jürgen Giesow, Regional Manager for Arburg, who presented a paper at the Molding 2014 conference in Newport Beach, CA, on March 3, 2014. You just have to think outside the cleanroom box, he told attendees.

Conventional cleanrooms with fully integrated molding machines are vast spaces. Specifically, they need high ceilings, in the 14- to 16-ft range, to accommodate robotic equipment and cranes to move molds. The cost to maintain air quality at a level that is compliant with the relevant ISO classification skyrockets as the square footage expands. One solution is to build a modular, decentralized cleanroom with a dock for the molding system.

Parts are molded in the clean area and placed on a conveyor for assembly and packing. A laminar flow system that sits on the machine and an integrated ionization system prevent contamination and electrostatic charging of the molded parts. The system that Giesow highlighted at the conference was equipped with a Multilift robot, but the parts could be dropped onto the conveyor if they are not especially fragile.

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It is also worth noting, as an aside, that Arburg has introduced a number of innovations in its molding machines to minimize particle generation. Giesow cited the use of direct-drive instead of belt-driven motors; employing water rather than fans to prevent overheating; and rotating the nut, rather than the spindle, in the clamp area, as examples of the detail-oriented thinking for which Arburg is known.

The advantage of a modular cleanroom architecture, according to Giesow, is that the molder will need to maintain a clean area that is approximately one-quarter the size of a conventional cleanroom. This concept is quite popular among medical molders in Europe, but has only recently started to get attention on this side of the pond. The reason, says Gieslow, is cultural more than anything else.

"Why are there more electric cars in the United States and more diesel cars in Europe?" he asks rhetorically. "It is what people are used to, what they feel comfortable with." The same goes for cleanroom molding, but that doesn't mean minds can't be changed.

Anyone who bothers to sit down and calculate the cost efficiencies of the room-in-a-room concept will walk away with a different perspective, promises Giesow. The concept is gaining traction in North America, he adds, noting that Arburg currently has "three installations, all of them medical, running here."

— Norbert Sparrow