Modern Plastics Worldwide - July/August 2009 - dae uptlax

Bayer MaterialScience’s
new Makrolon Rx2435
is used in
catheter connectors.
Potential thin-wall applications for Makrolon
Rx2435 include dialysis components,
catheter connectors, surgical instruments
—such as tracers, retractors and handles—
and drug delivery devices, he adds.
Dunay notes that SUD makers continue
to look at both new devices and “next-gen”
products. “Certainly it’s easier for the OEMs
to make small changes to a device they have
a history with,” he states. “They are continuing
to look at new technology, but they want
to be cautious, too, because they need a high
degree of safety and reliability.”
Sabic’s O’Brien explains that the OEM
typically works with the end user as they’re
designing new products. “The surgeons want
the feel—especially when an instrument goes
from metal to plastic—that it’s sturdy and
that it feels right in their hands. They need
the instrument or device to work the same
way each time.”
O’Brien says that in light of the economy,
new designs get put on hold more than they
used to. Also, approval time for new designs
can take a long time. “It might be more cost-
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effective to tweak a design on something
that’s already proven as it’s easier for them
to launch a redesign than come out with a
whole new product,” he says.
Single versus multiple use
If medical device OEMs move increasingly
toward SUDs—even in surgical
instruments—has the need for sterilization
waned? Sabic’s Devito says it’s not necessarily
the case. “It’s still critical in application
development to look at sterilization requirements,
and it’s one of the main questions
asked in the development process,” he says.
“I think it’s all about efficiency. And it’s still
one of the main CTQ (critical to quality)
issues when device makers promote their
products in healthcare.”
Bayer’s Rx2435 grade also addresses the
increasing demand for a radiation-stabilized
ISO certifi cation opens medical doors
Mack Prototype Inc. (Gardner, MA), a division of custom injection molder Mack
Molding Co. and specializing in SLA rapid prototyping, CNC machining, and injection
molding (8 presses sized 10-230 tons) for low-volume, small-to-medium parts
processing, recently received its ISO 13485 certifi cation, the international quality
standard for medical device manufacturing. “Achieving this quality hallmark uniquely
positions us as a prototype house and low-volume manufacturer, as many manufacturers
our size are not certifi ed to this stringent medical standard,” says Rick Perry,
president of Mack Prototype. “It will put us at the table with major medical OEMs,
who require suppliers to be certifi ed to ISO 13485 in order to quote new projects.
And based on customer needs, it will allow us to partner with Mack Molding, which
is FDA registered and has been certifi ed to ISO 13485 for several years, to provide
a low-volume solution for major medical OEMs.”
Michael Hanson, senior technical development engineer at the processor,
explains that when designing medical disposables, it’s important to start with a target
cost, which narrows the scope of possibilities. “Another often overlooked step is to
clearly defi ne that part’s requirements,” Hanson says. “The overall goal is to meet the
part requirements at the lowest possible cost, so this is where you must start.” Other
design considerations he mentions include avoiding sharp edges that could easily
prick surgical gloves; avoiding thin and thick sections to minimize molded-in stress
levels and part warpage, and, of course, choosing the correct resin.
medical grade of polycarbonate. It is gammastabilized
and typically offered in the color
Gamma (color code 451118), but can also
be colored in any of the company’s other
Rx Medical colors, all of which meet the
requirements of FDA-Modified ISO 10993,
Part1 tests with human tissue contact time
of 30 days or less. Sabic’s portfolio includes
materials that can meet every type of sterilization
requirement including gamma and
steam autoclave, which are the primary
methods, notes O’Brien. “With gamma you
have color shift but our products have color
stabilizer in them so when PC devices are
gamma sterilized they don’t shift toward yellow
as much. It will shift a bit, then go back
to clear. A lot of disposables are gamma
sterilized because it’s quick.”
With steam autoclave sterilization, there
are two temperatures used, 134ºC or 121ºC.
“Hospitals prefer the 134ºC because it’s
quicker. You’re talking more robust materials
for that, so it’s a trade-off. A lot of disposables
like Y-sites, stopcocks, are PC that is
generally gamma sterilized at the OEM, used
once, and tossed. It all depends on the type of
sterilization method,” says O’Brien.
O’Brien is confident about the strength
of the SUD market, but with reservations.
“I think we’re seeing more applications
and new products, but we’ve also seen
that healthcare isn’t recession proof,” he
says. “We’ve seen budget cuts in hospitals,
OEMs moving a bit slower on new
products than they used to. It’s still a
good market, but they look at costs a lot
more closely than they used to and ask
that big question: What can I do to take
costs out? MPW
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MODERN PLASTICS WORLDWIDE • JULY/AUGUST 2009 31