For example, Tepha Inc. (Lexington, MA), a medical device firm pursuing the development and commercialization of products based on the company’s proprietary biomaterial technology, recently installed its third American Kuhne line. The three run monofilament, tubing, and multifilament products. The processor’s materials offering is centered on a new class of absorbable biomaterials, polyhydroxyalkanoates (PHAs), which may be tailored to meet the requirements of medical devices in multiple fields.

Another of the manufacturer’s medical customers, Vesta Inc. (Franklin, WI), is a relative old-timer in the medical market with more than 35 years' experience serving medical device manufacturers with medical-grade silicone molding and extrusion. “We are currently running small-bore, tight-tolerance silicone tubing, both single- and multi-lumen, with our American Kuhne extruders,” said Bill Woinowski, R&D manager at the processor. He points to the equipment’s unique feed section and durable construction as reasons why his company plans to add to its American Kuhne stable in its next expansion.

American Kuhne’s dedication to the medical market includes plenty of time on the road; for example, it was the only plastics extruder manufacturer exhibiting at the Medica trade show last November in Düsseldorf, Germany. The company also runs a medical tubing line each year at the MDM West tradeshow (organized by MPW’s owner, Canon Communications), and also other attends medical tradeshows throughout North America, Europe, and China.

The manufacturer’s most recent development for the medical market is its LTRA R/S extruder line for processing silicone. The extruder’s design includes a proprietary, hinged roller-feed assembly that it says is easily opened by loosening two swing bolts, providing access for common service and maintenance. The scraper blade is also easily accessed for adjustments or removal. The casting of the machines is nickel-plated and the hinged arm and hardened feed liner are stainless steel for abrasion and corrosion resistance. There is an integral water-cooling jacket in the feed-section casting, and the chrome-plated hardened feed roll also is internally cooled. A second hinge opens to ease removal of the feed roll and bearings for service. Feed roll bearings feature special seals to minimize silicone contamination; spare feed rolls and bearings can be provided for quick rotation during material/color changes.

The company’s established Ultra MD series of extruders are designed exclusively for a variety of medical applications. These extruders are typically painted medical white and come with stainless steel guarding, closed loop AC vector drives, and optional pressure feedback control. There is also a replaceable feed section liner, which provides the flexibility to configure the feed geometry to best suit the application.

According to the manufacturer, more than half of its orders from the medical market are for complete turnkey tubing systems. The manufacturer says it recently shipped a line capable of an 800-ft/minute line speed for processing of a flexible PVC product plasticized using a non-DEHP-containing phthalate.

Output, so prominent a statistic in most extruded applications, does not always take precedence in the medical field. For instance, applications such as microbore tubing, typically used for minimally invasive medical procedures, are ones where quality in terms of tight tolerances trumps output.

The company claims a strong market share in Ireland and mainland Europe, with support from its partner Kuhne GmbH in Germany. A complete lab line is currently being installed in the German manufacturing plant to facilitate local applications testing and sales. In September 2009 American Kuhne signed an agreement with HnG Medical to provide technical sales support specifically for the fast growing medical market in Asia. HnG, headquartered in Ontario, Canada with offices in China, distributes disposable medical devices and components manufactured in China in the Americas, and exports equipment and raw materials to Chinese medical device manufacturers. —[email protected]