2011

Die Extrusion Technology for Medical Tubing Applications

Patent-pending process would allow 1000-plus layers from a single extruder.

Although the concept of nanotechnology (controlling matter on an atomic scale) dates back to 1959, it is only now becoming more commercially realized. It has the potential to challenge the way all products are extruded in almost every type of medical tubular or related industrial product applications.

altNanoFlow™ die technology builds upon earlier engineered benefits, including thin walls and high-strength tubing in a variety of materials required for high-speed and high-volume applications, as well as an ultra-low-volume design that minimizes the polymer residence time in the chamber for certain types of medical tubes.

Guill’s NanoFlow die extrusion technology is specially designed to create an environmentally friendlier or “greener” end product in medical applications, an increasing concern for manufacturers that face strict governmental regulations.

Access to the right tubing that is engineered to meet or exceed the medical industry/OEM’s demands is always a primary objective. Nanotechnology dies serve as a key instrument in the toolbox of solutions that can improve upon the limitations of today’s tubing.

Advanced nanotechnology, when used in extrusion tubing as opposed to the conventional format, offers significant savings through the use of less material and/or less expensive material, as well as a reduction in different materials needed for production. In working to overcome the limitations of a number of layers to use in tubular or hollow products, far more layers can now be extruded, giving manufacturers the ability to create an extremely wide range of advanced medical tubes to fulfill the growing list of specialty products.

When manufacturing any type of tubing, every tooling application aims to lower production costs while optimizing the extrusion process, and increase productivity while reducing the overall cycle time with better quality and precision.

These essential production benchmarks are extremely important for manufacturers in today’s competitive marketplace. For medical tubing like high-pressure catheters, angioplasty devices, stent delivery catheters, and medical balloons (implanted tubing or other inserted in the body for extended time periods), the material properties — mechanical, physical, chemical, electrical, and thermal — are especially critical to their proper functioning. These types of medical devices in particular, along with many others, illustrate the increasingly diversified arena of medical tubing products.

Whether for high-end diagnostic or therapeutic catheters, in most of these essential medical tubing applications, the unwritten industry rule is generally to make smaller tubes with thinner walls. Today’s medical OEM needs to be equipped with the latest technologically effective and non-invasive tubular products in order to inspire the provider and build patient confidence.

In the never-ending quest for improvement in medical tubing, the NanoFlow die (patent pending) is poised to create 1,000-plus layers from a single extruder, as opposed to roughly fewer than a dozen layers prior to the NanoFlow’s development. The NanoFlow’s layer thickness is in the micrometer (1 millionth of a meter) to nanometer (1 billionth of a meter) range.

The end product of NanoFlow tubing features multiple layers that are not distinguishable to the naked eye alone, very similar to a multilayer bottle produced by blow molding techniques. Unlike a multilayer bottle, however, when looking at the NanoFlow tubing, one cannot distinguish the number of layers. Perhaps a better analogy is a layered piece of plywood, where almost all of the layers are indistinguishable to the viewer even when looking at it from the side.

Barrier properties, such as when sensitive materials require protection from the air, can be better engineered by designing the thinnest layers, which will force materials to crystallize. Gas (O2, H2O, EtOH) barrier-type properties will also be made possible with the proprietary NanoFlow tubular die technology. Optical and mechanical properties will be enhanced as well. Better mechanical properties will create increased impact and fracture toughness. An increase in ductility can mean an increase in tear strength. Strong, brittle materials prone to crack propagation can be combined with soft ductile layers to limit the crack propagation.

Nanotechnology promises a whole host of benefits, but what remains essential to most manufacturers is the significant savings they’ll incur through the use of less material and/or less expensive material, not including the reduction in different materials needed for extrusion.

With state-of-the-art 3D CAD, CFD, and FEA (Finite Element Analysis) to assist engineers in the nanotechnology process, customization of the die will be key in accommodating critical characteristics included in every final product created from extrusion tubing.

This technology was done by Guill Tool & Engineering Co., West Warwick, RI. For more information, visit http://info.hotims.com/34454-164.