Pushing the Limits of Performance

Pushing the Limits of Performance

Please provide a brief statement about the current state of the extrusion market for medical devices/products/components.

In general the extrusion market is still striving. A substantial uptick of recent M&A activities specifically in the OEM-side of the business has made merging or acquiring companies look at their core competencies again.

Some have decided to potentially outsource in-house extrusion to companies with a large breath of capabilities such as RAUMEDIC in order to be able to focus on their core competencies and to free up manufacturing space for new projects coming on board to achieve the revenue growth demanded by Wall Street.

What are the latest trends in extrusion that you are seeing in the industry?

Recent years were all about extruding smaller dimensions, with tighter tolerances and with more and more challenging tubing designs. All of which can be offered by Single Source Providers such as RAUMEDIC. Due to a hot M&A market RAUMEDIC has experienced a lot of requests for extruding “good old” single wall high runner tubing such as PVC tubing used e.g. for infusion sets. As we are very experienced in lean production and high volume extrusion this plays wonderfully into our global production concept with help of our brand-new, state-of-the-art and class 10.000 (Class 7) clean-room production in Mills River, NC. Our first US manufacturing and design center was just opened starting this year.

  • Extruders are producing tubing with extremely small dimensions, tight tolerances,
    and challenging tubing designs.

What are OEMs asking for the most when it comes to extrusion methods?

A high quality standard is assumed as a given by our clients, whereby this needs to be supported by in-line controls such as laser microscopes or ultrasound devices. Such devices are necessary to have in place to document a repeatable, reliable and stable extrusion process. Price is always a big driver, whereby focus on lean manufacturing and high-speed extrusion capabilities needs to be given. However, also versatility with regard to materials and in the case of PVC, plasticizers applied, is coming more and more into play due to the current outsourcing trend of high-runner tubing business. With regard to high volume PVC tubing demands we see a tendency to shift away from traditional plasticizers such as DEHP, to alternative plasticizers such as DINCH, DEHT, or TOTM. One reason is that the European Union (EU) has taken the lead by classifying DEHP under the category of carcinogens, mutagens, reprotoxins (CMRs) and endocrine disrupting substances under their Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) regulation. The EU has issued a sunset date set on February 2015 for most applications on the use of DEHP, meaning that EU member states will need to also adhere to by their local law. It should be mentioned that Medical Devices fall under EU’s Medical Device Directive, but this does not prevent EU member to enforce much stricter laws, such is the case of France which has put in place a ban of DEHP for neonatal and nursing-mother applications starting July 2015. On EU level there are also first calls for substitution of CMRs and endocrine disruptors from all medical devices by 2026.

In the US the State of California sticks out with Preposition 65, which was a first in continental US requiring companies to clearly identify and label DEHP as an ingredient with cause of concern. The Environmental Protection Agency (EPA) initiated an Endocrine Disruptor Screening Program to also review DEHP. However, it is also necessary to note that the Food and Drug Administration (FDA) has pointed out that it did not have a cause for concern for the continued use of PVC or DEHP for most medical devices. Nevertheless, this discussion is now going on for many years and it has not gone away, so a change of regulatory requirements might be looming. More and more companies, also here in the US, are therefore on the lookout for an alternative to DEHP plasticizer, or even PVC overall. With regard to PVC substitution new alternatives such as Polypropylene (PP) blends, and Thermoplastics Elastomers (TPEs) have been developed and are ready available. Those alternatives closely approach the performance of PVC, but might require a different approach to design and manufacturing process when it comes to bonding to other substrates. Specialized extrusion houses such as RAUMEDIC can facilitate a change to new plasticizers or base materials.

Any new technologic advancements in the last year or two that I should elaborate on, and how they make things better or more efficient? How are the technological/production limits of extrusion being pushed?

One specific technologic advancement I would like to single out is the market launch of medical-grade RAUMEDIC PTFE Moldflon™ tubing which is a symbiosis between PTFE properties and thermoplastic processing capabilities. PTFE Moldflon™ has very similar physical properties as compared to standard PTFE, such as high temperature and chemical resistance, very low coefficient of friction and tensile strength. The big difference however is that PTFE Moldflon™ is pelletized and can run continuously on a standard extrusion line, whereas traditional PTFE is a batch process and therefore non-continuous using RAM extrusion lines. PTFE Moldflon™ can therefore be run on micro extrusion lines for ultra-thin wall thicknesses down to 0.0005” to produce inner catheter liners, without the need to be drawn / necked down as necessary with standard PTFE. The biggest advantage of PTFE Moldflon™ however stems from its thermoplastic processing capabilities as this allows additional thermoforming operations on the tube such as tipping and flaring, without showing common manufacturing related issues such as shearing, cracking or flaking. It also can be easily co-extruded with Barium-Sulfate (BaSo4) stripes, which is widely used in IV catheter tubing. Also very fine Platinum / Iridium (Pt-Lt) lead wires of 0.001” can be continuously insulated / coated with PTFE Moldflon™, whereby the physical properties of those very fragile wires are protected. Such wires are e.g. used in cochlear implants to electrically stimulate the cochlea.

Moldflon™ is a registered trademark of ElringKlinger. For more details on Moldflon™, visit www.ElringKlinger-kunststoff.com

Any challenges with new or advanced materials?

In recent months we have seen an interest to substitute Polyvinylchloride (PVC) tubing with alternative materials, not only to move away from Chlorine-based materials, but also to increase drug dosing efficacy. Independent studies using Nitroglycerin have shown that PVC is prone to adsorb drugs and critical drug components and therefore raising questions on the dosing accuracy of drugs supplied to the patient with help of PVC based medical devices. Alternative materials to PVC could be Thermoplastic Elastomers (TPE) or Polypropylene blends (PP). TPE’s however are not easy to bond to other substrates, such as Polycarbonate (PC) or ABS connectors, which are widely used in standard IV tubing sets. Good bonding characteristics can be achieved with PP tubing using Tetrahydrofuran (THF).

How about regulatory/FDA challenges – any relevant aspects to discuss for extrusion methods?

Undoubtedly the MedTech industry is becoming more and more risk averse. This could be a good thing if it comes to consumer and patient safety, which always should be a first. However, this could also backfire in case this leads to over-regulating and finally to over-engineering when it comes to quality features. Both could be to the detriment of trying to making medical-devices more affordable and less expensive, as both are associated with higher costs and longer time to market, all negatively contributing to a company’s profit line. Recent years seem to have seen an increase of regulatory requirements being pushed on to Engineering departments with equal or maybe even less staffing. There is plenty of Engineering manpower and Engineering resources needed to qualify and validate new products or simply if there is a need to re-validate due to production or material changes. Some of this manpower seems to be blocked by the regulatory work they need to comply to, decreasing the flexibility of companies to react to specific market changes.

Please share some examples of innovative extrusion solutions that you came up with to meet challenging customer requests – can be new technology/modifications, best practices with existing approaches, etc.

We have been frequently asked for co-extrusion (multilayer) solutions to combine Thermoplastics with Silicones. For a long time it was considered to be unimaginable to achieve a good bond between both materials, but RAUMEDIC is now offering exactly such under its SILEFIN brand. In collaboration with an University Institute, RAUMEDIC has now succeeded in taking an important step forward. Thanks to a fundamental innovation, Polyolefin as non-polar thermoplastics or other high temperature materials such as Fluoropolymers can be combined with a Silicone elastomer, thus forming a superb adhesive bond. This allows now to produce co-extruded tubing, whose silicone outer layer provides outstanding pump characteristics and excellent resilience for pump tubing applications, e.g. for peristaltic pumps. At the same time the Polypropylene (PP) inner layer with its distinct hydrophobic properties and low gas permeability shows almost no interaction with the flow medium running through the tube.

This Q&A was done by Mark Crawford for Medical Product Outsourcing, April 2016