Experience in the medical market and knowledge of current manufacturing trends and regulatory issues are among the most important criteria to look for in a contract extruder.
|Increasingly tight tolerance requirements are pushing engineers to “think outside the box,” says Kenneth Koen of Creganna-Tactx Medical.
When looking for an extrusion supplier, always begin with the end application in mind, advises Richard Jokinen, Sales Manager EMEA, Creganna-Tactx Medical (Galway, Ireland; www.cregannatactx.com). Then identify step by step what is needed to get there. The extruder you ultimately choose should offer capabilities that meet your needs as they change throughout the production cycle, he says. For instance, when a project is in the early development stage, the supplier should be able to provide quick turnaround of prototypes. In steady-state production, however, consistent quality and delivery performance are critical. Another consideration is the extrusion vendor’s ability to manage safety stocks and consigned inventories when the product is in steady-state production, Jokinen adds.
Medical device experience required
Experience in the medical market is probably the most crucial criterion for a vendor. “Long-term experience in the medical device arena is required because of the specific documentation and product quality requirements,” says Ralf Ziembinski, Head of Application Technology Business Team Extrusion/Tubing at Raumedic AG (Helmbrechts, Germany; www.raumedic.com
). “For most medical tubing applications, high precision is required when it comes to tubing dimensions, but also for the material parameters of the polymers,” he adds. A number of factors challenge the expertise and resources of extruders serving the medical device market. These include the increasing specialisation of extruded parts, ever-tighter tolerances of medical tubing, growing demand for micro-tubing and multilayer extrusions and increasingly strict regulatory oversight.
“Device manufacturers rarely have the time to educate vendors that lack prior [medical] experience on the criteria for qualifying as a supplier of parts or assemblies for this industry,” Creganna’s Jokinen says. Conversely, the ability to proactively assist device manufacturers in the development process can save time and money for both parties.
Keep it clean and safe
When manufacturing medical devices, it is important that the level of environmental pollutants such as dust, airborne microbes, aerosol particles and chemical vapours are kept to a minimum. Hence, producing medical devices under cleanroom conditions is almost a given these days. “Cleanroom production, generally under Class 10 000 conditions, is obligatory for medical extrusion, and specific monitoring of the biological and particle contamination of the product is essential,” says Raumedic’s Ziembinski. He adds that it is vital to guarantee cleanliness and purity in the production process as well as in the materials used.
|Micro-extrusions, ever-tighter tolerances and increasingly complex designs of sections are among the current trends in medical extrusion, says Mark Ostwald of Helix Medical.
Another important consideration is the certification required to produce for the medical device industry. “A prospective supplier should have an understanding of the regulations and quality systems involved in manufacturing medical device components,” says Mark Ostwald, General Manager, Helix Medical Europe KG (Kaiserslautern, Germany; www.helixmedical.com). He recommends looking for a supplier with the necessary ISO certifications as well as US FDA and CE marking. The CE mark, for instance, confirms that a product has met EU consumer safety, health or environmental requirements. Furthermore, additional legal requirements must be considered such as a quality management system that allows product recalls in case of a safety issue.
Consider current extrusion trends
A medical device manufacturer also should ensure that the supplier is up to speed on current trends in medical extrusion and that it possesses the appropriate technology and expertise. “Many extrusion companies now offer added value in terms of further processing,” Ziembinski says. “Few medical device companies purchase tubing on reels or as coils for further processing in their own assembly processes,” he says. “Especially in catheter applications, the provision of [additional] assembly processes is expected from tubing suppliers.” He explains that this includes technologies such as printing, cutting, stamping drainage holes, thermoforming, tip-forming and special packaging.
|Multilayer extrusions are used to fabricate specialised packaging film and tubing that is compatible with therapeutic agents.
Another trend is the demand for ever-tighter tolerance requirements, according to Kenneth Koen, Director of Extrusion Operations at Creganna-Tactx Medical. “Our customers have asked for tubing walls to be as thin as 0.0007 in. with a tolerance of 0.0003 in.,” he says. “This has really pushed extrusion engineers to ‘think outside the box’ by designing precise tooling and implementing new processing steps to assure the customer that the project will be a success.”
According to Ziembinski, there is also a growing demand for micro-tubes for the fabrication of catheters used in minimally invasive surgery, life support devices for neonates and microfluidic systems. “And there is an opportunity to [achieve] even tighter tolerances on certain tubing,” he adds. “This is a result of greater precision in extrusion technology but also in improvements of the corresponding in-line measuring equipment.”
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