In the world of medicine the need for a low friction coating that is both extremely slippery and biocompatible has led to the use of fluoropolymers such PTFE. When compared to other plastics the fluoropolymers exhibit far more lubricity and have been shown to offer the most with a coefficient of friction (CoF) of only 0.1, the next nearest in the list is fluorinated ethylene propylene (FEP) with a rating of 0.2.Fluoropolymers have been shown to be excellent for medical use as they are exceptionally biocompatible and have been used successfully for a very long period of time as a low friction coating. All medical grade fluoropolymers must meet the standards established under USP Class VI and ISO 10993 testing standards. The specialized properties of these fluoropolymers have led to the development of a multitude of next-generation medical devices.
Continued development of these polymers has led to the development of next level catheters such as those used in neurological surgeries and in the creation of many other new and innovative medical devices. For example coating the inside of a guiding catheter with PTFE that is used to place stents into the proper location is made much easier since it has the lowest coefficient of friction of any fluoropolymer currently available. During the construction of the guiding catheter a low friction coating of PTFE is layered onto the outer diameter of the tube. Thus when the stent is in place the catheter can easily be removed. This task is so critical that FEP is not slippery enough to be used successfully. So the question most people ask about a substance that is so slippery that nothing will stick to it is" How does it stick to anything"? In essence it does not actually stick to anything it is bonded to another material by a process of etching or chemical bonding. In the process of making a thin walled tube a fraction of the fluorine atoms are removed from the surface of the tube and materials that are more amenable to adhesion to another surface. This is how the low friction coating on the inside of the guiding catheter is applied to allow the stent to be placed in the proper location. In many cases the tubing being used must not only have a low friction coating that allows it to be slid place but then the tubing must be able to be removed by tearing it apart leaving the primary device in place.
This process known as a PTFE Inducer was invented in the 70s by Cook Inc. and uses a process that aligns the grain of the PTFE in the tube longitudinally and then the tube is scored along both sides. This is similar to the way many plastic food packages are made with an easy rip opening. When the device is in place the surgeon can then rip the tubing apart leaving the device in place with minimal invasive procedures needed. With ten years in the business of creating and applying coatings for the medical world Surface Solutions Group can provide you with a broad array of coatings. From low friction coatings to antimicrobial coatings, many of their coatings include the features of both in the same layer. All coatings are applied in their state of the art sterile facility and their engineering department has the skill and knowledge to help you with any of your coating needs.