Technical proficiency, process transparency and a customer-centric approach are among the key attributes you should seek in a partner
Medical device manufacturers may decide to outsource extrusion services for various reasons. The volume of business may not justify investing in an internal extrusion department, for example. Or extrusion technology may be considered peripheral to the core business. Regardless of the why, however, it’s important not to neglect the how. Numerous factors need to be taken into account when recruiting a subcontractor of medical extrusion services. Some are obvious, such as ensuring that the initiative makes commercial sense; some are less so. If you are shopping for an extrusion specialist, here are a few points that you might want to consider.
Finding the One
To earn the title of supplier of choice, the extruder must maintain R&D momentum in medical device extrusion and materials technologies. The vendor should have the capacity to innovate and solve problems and be in a position to collaboratively develop new technologies and products, funneling technical expertise to your company’s engineering and R&D teams. Don’t dither on starting your search: finding the right partner and applying that expertise early in the design cycle can accelerate time to market and reduce overall costs.
Leverage your partner’s expertise to identify options and cost solutions that meet your specific needs. If you are developing a balloon blowing process, for example, you should expect to receive guidance on the tubing’s mechanical properties.
Developing and specifying meaningful tolerances for custom tubing early in the design cycle delivers long-term benefits. Over tolerancing (i.e., specifying a tight tolerance window) extrusions can have cost implications: additional technologies such as melt pumps, vacuum tanks and over-the-wire extrusion may be needed to achieve desired results. This can lead to longer setup times and slower run speeds that will ultimately affect costs.
Look for Transparency
It can be instructive to match potential cost options with various tolerances. This information will allow your design team to make informed commercial and product risk decisions.
Maximising tubing functionality and performance requires a systematic approach to extrusion and a thorough understanding of polymer characteristics. Selecting the right polymers is half the battle; processing and handling is the other half.
Your extrusion partner should embrace transparency when collaborating with your engineering group on materials and product developments. Some subcontractors like to suggest that their processes and material formulations are proprietary. In fact, much of this information is basic. By withholding this information, the company hopes that you will think twice before taking your business elsewhere if you are dissatisified with its services. Before signing on with a supplier, make sure that the channels of communication are open to your engineering and extended teams.
Reducing Lead Times and Inventory
In today’s marketplace, flexibility is key. As medical device companies seek to reduce stock levels, particularly in the current economic climate, the ability of extrusion companies to respond with short lead times can be extremely beneficial.
New product development lead time is a critical factor for med-tech design and development groups. A two-week turnaround can be considered competitive in the current market. This allows time for tooling development, material procurement and an extrusion trial in most cases. Your partner should make available a dedicated and responsive trials group focused on developing new extrusions to ensure lead times are met.
When the outsourced business is up and running, your extrusion partner should be able to add value by further scaling back inventory by implementing kanban systems, for example.
To capitalise on the growing market for medical devices, extrusion companies must continue to develop and integrate a range of strategic competencies and support systems. Management-led systems such as lean manufacturing should be in place to reduce the amount of waste that is produced, improve overall customer value and minimise the need for future price increases. Lean activities improve all aspects and functions of a business from manufacturing to management.
All technology-based businesses should foster a culture of continuous improvement and create an environment where everyone is focused on quality and adding value.
Making Metrics Matter
Consider establishing a service agreement with your extrusion partner. Forge an understanding on the key metrics that you and your vendor will monitor. These may include lead times for production and trial orders, product quality expectations and the complete on-time delivery of product shipments.
A good extrusion partner should be prepared to send a representative to your site for regular performance reviews. This commitment in and of itself can be a good indicator on how actively your partner will work toward achieving the agreed metrics.
Significant outsourcing initiatives with scale and complexity should be supported by detailed project plans and milestones. Your extrusion partner should be willing to send a representative at key moments of the project to review plan adherence.
It’s a Science, Not an Art
From a nuts-and-bolts perspective, the extruder must be able to consistently supply product that meets specifications.
The supplier should be accustomed to working with a range of materials such as antimicrobials, radiopaque formulations, Pebax, nylons, FEPs, PE, TPEs and custom compounds, and be versed in biocompatibility issues. The vendor also should be knowledgeable about the compatibility of materials with downstream processes. Some material resins must be appropriately dried prior to processing, for instance. Using suitable technology to control material moisture prior to and during the extrusion process has a major impact on the extruded tubing.
Medical extrusions can be very complex, and you will want your supplier to have the capabilities to work with multiple layers and lumens, tapers and bumps, thin walls and tight tolerances.
Achieving best-in class-tolerances requires precisely defined equipment such as cross heads, tips and dies. Dies are now manufactured to engineered concentricity specifications (maintaining concentricity becomes more complicated when layers are involved). Extrusion companies must have comprehensive tooling maintenance and cleaning procedures in place to ensure quality products that meet dimensional and cosmetic specifications.
A range of different size extrusion machines should be available to ensure the right size machine is available to meet customer needs. Extrusion systems used to manufacture microbore tubing (PTCA inner shafts, outerbodies and balloon tubing) are usually small highly controlled machines with 0.5–1.0-in. screw diameters. Larger tubing will require bigger extrusion machines to reach line speeds that will generate a cost effective product. It takes more than having the right size extruder, however, to consistently produce adequate tubing.
For example, microbore tubing with outer diameters (OD) measuring less than 0.5 mm requires unprecedented levels of dimensional accuracy and state-of-the-art technology to minimise variation. Extrusion companies must be able to meet OD tolerances in the ±0.0007 to 0.001 mm range. For very precise extrusions of this nature, puller and cutter technology with the necessary software and cooling tanks to allow for vacuum sizing may be necessary. Pressure control systems at the cross-head and melt pumps are widely used to further minimise process variation. Closed-loop control on extrusion lines between air bottles, on-line measurement systems and cutters are also essential in controlling variation.
As many medical device manufacturing companies operate to Six Sigma process capability levels, it is reasonable to expect your extrusion partner to do the same. Most extrusion companies have gauging devices on-line that are capable of continuously measuring outer diameter, wall thickness and individual layers. Measurement data is gathered over the duration of the run and is used to generate statistical information in the form of process capability data. This data should be available for every production order, providing confidence in product quality over the entire production run.
Your Partner’s Partner
Particular attention should be given to the extent to which your extrusion partner, in turn, partners with key materials suppliers. Extrusion is a continuous process, and raw material variation can have a significant impact on output in terms of dimensional stability, mechanical performance and visual quality. Basic material assessment techniques, such as melt flow analysis and moisture analysis, should be in place to monitor for raw material variation.
Trust but Verify
Competent forward-thinking extrusion companies will invest both in extrusion and quality technology and will increase their capacity and upgrade facilities on an ongoing basis. Challenge your potential partner by asking if he or she has the capacity to support your business as it grows.
It is always good practice to visit your intended partner to assess and audit operations. Are the required quality systems in place? Is the facility controlled to minimise bioburden and endotoxin risks for your product?
Extrusion companies should have robust quality systems independently certified (to ISO 13485:2003, for example) and classified cleanrooms. They should also be able to provide you with comprehensive test data relevant to your product (dimensional, burst, tensile and elongation testing). Measurement equipment should be adequately qualified and maintained to ensure good gauge repeatability and reproducibility.
Inspection equipment is becoming more critical for suppliers. Make sure that your prospective partner has the technology to appropriately sample and inspect tubing.
More than extrusion
Final consideration may be given to the extruder’s ability to add value beyond merely supplying a component. Inquire about downstream processes such as braiding, side-hole porting, tipping, welding, skiving, flaring and shaping. Some extrusion companies provide design services and have the resources to assemble all those processes and bring extrusion-based medical devices from concept to commercialisation.
When all is said and done, the company you partner with will become, ideally, an extension of your organisation. The vendor should have a keen understanding of your expectations—short lead times, Six Sigma capability, metric management techniques, technical support and a breadth of extrusion competency—and the wherewithall to meet and, perhaps, exceed them.
About the authors
Antoinette McTigue, PhD
A graduate of University College Dublin, where she received her PhD in industrial microbiology, Antoinette McTigue worked in the pharmaceutical industry with Wyeth Medica for a number of years in the role of Manufacturing Manager before joining ANSAmed as Manufacturing Director in 2001. She is responsible for manufacturing, maintenance and logistics.
After working in technical and quality management positions for companies such as Boston Scientific, TFX Medical and SteriPack Medical for more than 10 years, Shane Healy joined Ansamed in 2004. Initially responsible for QA, he now heads the company’s sales team and new business development. He is a graduate of University College Galway and Galway Mayo Institute of Technology. Healy can be contacted via e-mail at firstname.lastname@example.org
Ireland-based Ansamed (www.ansamed.com
) is an established provider of catheter systems and design services to the medical device industry. With a team of 75 people, it has been supplying medical extrusions to industry for 17 years.
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