Market Focus: Medical Equipment

Takea look at the medical market, and you see a microcosm of the entireinjection molding community. In speaking with two multimillion-dollarmolders

that service the medical device industry, the same trends emergedthat have been apparent in other market segments: the impact ofmergers and acquisitions, partnering with OEMs, and the increasingrole of the Internet.

"Virtually our entire customer base is involved in sometype of acquisition," says Jim Dolan, vp of sales and marketingfor the Tech Group (Scottsdale, AZ). For smaller molders a mergeror acquisition can mean less business as nonmolding operationsare absorbed into the OEM. However, this is not the case for theTech Group. While a number of customers have pared down theirmassive supplier bases, the Tech Group has, for the most part,made the cut. Its worldwide locations and full-service manufacturingcapabilities have proven to be an advantage during this type ofconsolidation.

George Paleos, industry manager, medical, water bottle, andfood contact for Bayer Corp. (Pittsburgh, PA), sheds some lighton one driver behind M&As in the medical industry. "Costcontainment efforts through managed care have led to a spate ofM&As as companies consolidate operations to reduce cost,"he explains. "Larger companies are buying technology ratherthan developing it in-house in some cases."

OEMs are also being squeezed byrising costs in the medical industry (see chart), and suppliersare feeling the pinch. "As far as molders are concerned,"says Paleos, "supplier requirements are becoming more complexwith shorter lead times and it seems that it's becoming commonpractice for some medical device manufacturers to outsource partor all of their assembly operations."

This outsourcing trend is echoed by Bob Scalese, health careprogram manager for the Tech Group. He reports that the molderis being called upon to provide expertise in designing for manufacturability."A lot of people are changing jobs these days and companiesare losing their experts in certain areas," he says. "We'vefound that fewer and fewer firms truly have plastics engineersthat can design a part and know that a tool can be designed aroundit."

At Nypro (Clinton, MA), the Internet has played a significantrole in partnering the molder with its customers, enabling Nyproto provide a full range of contract manufacturing services. Itsfocus, says Tom Bienias, business manager for the health caregroup, is on stronger strategic alliances and partnerships. "Customersare coming to us to provide total solutions," he says. Inreturn, Nypro offers them dedicated program management, part design,tooling, prototyping, installation, qualifications, and validations,among other services.

"We have employed secure extranet sites for our customersto tap into real-time factory and business data," Bieniasexplains. "For example, a client can dial in to look at what'sbeing produced on the floor in any given day, what our yieldsare, our rejects, the shipments, and where they are."

As in other markets, being able to do more than just mold fora customer can lead to significant growth, which Nypro has certainlyexperienced. "A lot of it has to do with our ability to partneruniquely with many large health care companies," Bieniassays, "to take the burden off of them, and allow them tostick to new product development and speed to market. If you'regoing to be an injection molder only, I think you'll find yourselfslipping behind the opportunities."

 

PS CREATES ATIGHT SEAL
IN IRRIGATION ELECTRODE

The body of this suction irrigationelectrode manufactured by ElectroScope Inc. (Boulder, CO) allowssurgeons to conduct suction, irrigation, and electrosurgery atthe surgical site. Key to producing a safe, effective device wasthe polymer's adhesion to its metal substrate even after multiplesterilizations, and Dow's 30 percent glass-filled, impact-modifiedQuestra 2730 semicrystalline syndiotactic polystyrene was selectedto accomplish this.

"The challenge for the plastic," says Tom Wessel,development leader for Dow, "was that it needed to mold aroundthe metal insert, achieve part dimensions, and maintain a sealbetween the metal and plastic through initial autoclave sterilizationafter manufacturing and subsequent sterilization cycles afteruse."

Polysulfone, the material used for a prototype of the laparoscopicinstrument, allowed water to seep in. If this insulation failureoccurs along the shaft of the instrument during surgery, an electricalcurrent can burn human tissue near the leak area, say ElectroScopesources.

An Active Electrode Monitoring system from ElectroScope preventsburns caused by stray currents in its instruments, but the molderwas still pleased with the material's good encapsulation and itslonger life. For example, dimensional integrity of an insulatingmaterial generally deteriorates during repeated sterilization,but 15 parts molded with Questra survived 25 autoclave and cleaningcycles; polysulfone produced a 25 percent failure rate after thesame number of cycles.

Ninety percent of the device is molded with Questra, whilea liquid crystal polymer is used in the tip. Using existing tooling,shot sizes are less than 1 oz for both operations; cycle timeis around 30 seconds.

Dow Plastics
Midland, MI
Phone: (800) 441-4369
Web: www.dow.com

 

PC ANDABS PROVIDE HANDLING COMFORT

No one likes long recovery periodsafter surgery, and a grafting device for use in treating abdominalaortic aneurysms (AAA) promises to get patients back on theirfeet in two weeks instead of six to eight weeks. The goal of AAAsurgery in general is to repair an aorta that has been weakenedby an aneurysm, allowing blood to flow freely through the aortawithout the risk of aneurysm rupture.

In the traditional method of treatment, the surgeon entersthe body through an incision in the abdomen, opens the aneurysm,and sews a graft into place. Sometimes this can be more dangerousfor the patient than the condition itself. The Ancure EndograftSystem from Guidant Corp. (Menlo Park, CA), a one-piece polyestergraft, is inserted into a small incision in the groin area andis guided through the femoral artery in the upper leg and intothe aorta. A second incision is made for an X-ray imaging deviceand catheter delivery system. The surgeon can release the graftinside the aneurysm itself with a four-step deployment system;the graft then secures itself to the aorta with small metal hooksthat act as sutures.

Obviously, this takes a steady hand, and the handle for thedevice needed to respond to surgeons during the procedure. Guidantchose Makrolon polycarbonate and Lustran ABS from Bayer for thehandle components. "The catheter handle is used to guidethe graft into the patient's body-it had to be designed for surgicalperformance," says John Ordway, purchasing manager at Guidant'sCardiac and Vascular Surgery Group. "The Lustran and Makrolonmaterials allowed us to develop a handle for the catheter thatis comfortable, responsive, and easy for surgeons to use."Also, Makrolon is compliant with biocompatibility testing standardISO 10993, say Bayer sources, which contributed to its selection.

Bayer Corp.
Pittsburgh, PA
Phone: (800) 622-6004
Web: www.bayer.com/polymers-usa

 

EROGONOMICFORCEPS HANDLES
PERFORM WITH PPS

The last thing a patient wantsto happen to the surgeon during a procedure is for his or herhand to cramp up or get tired. Surgical Innovations Ltd. of Leeds,U.K. designed these minimally invasive surgery forceps to allowsurgeons to use the device in a more horizontal position as anextension of the hand, instead of vertically. The F4 Modular Forcepswon two Awards for Excellence (in medical and overall categories)at Interplas '99.

The forceps' ergonomically designed handles contain eight moldedcomponents, including a central core with stainless steel insertsand a cone that transmits rotation and insulates against highvoltage during electrocautery. Tony Laurenson, executive directorfor the molder, Electromag-Neil (Portsmouth, U.K.), says the complexcore molding was a critical element. "We adjusted [the handle's]wall thickness and discovered we had to feed from the end to controlweldlines and stress," he explains. "Most other cylindricalparts are fed from the center."

After rejecting glass-filled nylon for its lack of dimensionalstability during steam sterilization, LCP for its shortfall inweldline strength and surface appearance requirements, and polyetheretherketone(PEEK) for its expense, Surgical Innovations chose Fortron PPS1140 L4, a 40 percent glass-fiber-reinforced linear PPS from Ticona.The material's high strength (195 MPa tensile strength at breakand 285 MPa flexural strength) and low water absorption were factorsin the manufacturer's decision, as well as the price-90 percentless than PEEK. In fact, sources at Surgical Innovations say theymay be able to reduce or eliminate the metal inserts as a resultof the material's margin of stability and strength.

The British firm was also pleased with the surface appearancethat Fortron provided. "The components emerge from the moldclean and smooth, so they need almost no finishing and have aneven black and turquoise color," notes Stuart Moran, engineeringdirector for the forceps manufacturer. "This gives the handlesthe right feel for surgeons, who notice the slightest roughnessand stickiness and won't use devices that look cheap."

Laurenson says that the components made of the PPS meet tolerancesof .002 to .003 inch while holding 98 to 99 percent of their processingdimensions. Ticona assisted on the project with flow and structuralanalysis for the complex core and the thin-wall cone.

Ticona, Summit, NJ
Phone: (800) 833-4882
Web: www.ticona.com

 

Dental lightholds up to sterilization with PAEK

Count Luzzani DentalSrl among the many manufacturers looking to replace metal withlighter, less costly plastic. The molder of dental syringes choseVictrex's grade of polyaryletherketone, called Peek, to replacestainless steel for the point, switches, and gasket of the Minilighthandheld light. Because the removable tip undergoes repeated sterilization,the material selected had to withstand hot steam (273F and 14.5psi) and maintain good mechanical strength and stress crackingresistance. It also had to be pure and biocompatible.

High modulus and stiffness in the PAEK allowed the componentsto be designed with very thin walls, which took material usageand weight out of the part. In addition, its colorability, easeof processing, and excellent finish were factors in choosing thepolyaryletherketone.

Victrex USA Inc.
West Chester, PA
Phone: (800) 842-8739
Fax: (610) 696-5702
Web: www.victrex.com

 

ASSEMBLY STREAMLINED
IN NEEDLE-FREE SYRINGE REDESIGN

When IMM first reportedon the Medi-Jector needle-free syringe for insulin injections(May 1997 IMM, p. 64), LCP had replaced metal for a lighter,more user-friendly design. Now, the next generation, called Medi-JectorVision, has been designed with the manufacturer's three main goalsin mind: make it smaller and cheaper, and improve functionality.

Medi-Ject Inc. (Minneapolis, MN) collaborated with molder S&WPlastics LLC to improve the syringe's design. The instrument consistsof three elements: a spring-driven device, a needle-free syringe,and an adapter that mixes and loads the insulin into the syringe.The syringe component that contacts the skin was originally aplastic version of the stainless steel predecessor, with verysimilar geometry. Julius Sund, president of Medi-Ject, says ithad uneven cross-sectional thicknesses that were not simple tomold. It also had to accept attachment from the adapter axially,followed by a quarter-turn. In the Vision version, the syringecomponent overall is more uniform-easier to mold-and the adaptersimply snaps on axially over two thin wings. The drug is alsomore visible due to the component's new design.

Sund relates that the greatest processing improvement was realizedwhen part specifications were met consistently straight out ofthe mold. The housing, which incorporates a dosage window andinternal threads, had to be exactly calibrated for precise dosingaccuracy. Previous calibration took place through a number ofiterations that involved disassembling, adjusting, and reassemblingthe device.

The housing consists of Lubriloy PC (from LNP) overmolded withCycolac ABS (from GE Plastics). The plastic surrounding the interiorspring must withstand 100 lb of force and still provide low friction,which was a factor in the selection of Lubriloy. A winding grip,located at the opposite end of the syringe, is also molded withCycolac, with an overmolding of three .25-inch-wide ribs of VersaflexTPE from GLS Corp.

The nonsterile spring power pack has a life span of 3000 cycles,and the sterile needle-free syringe component is replaced after21 injections.

S&W Plastics LLC
Eden Prairie, MN
Phone: (952) 942-7760
Fax: (952) 942-7686
Web: www.swplastics.com