RiverTech Medical, a Vention Medical Co., has developed precision microtubing with variable flexibility for catheter-based medical devices. The microtubing offers two to three different stiffnesses and flexibilities within one tubing component for catheter-based medical device procedures such as angioplasty, stent placements, and thrombectomy.
Varying stiffness in catheter designs allow for optimum flexibility while maintaining the stiffness required to guide the catheter to its desired location. The product comprises a layer of Radel® polyphenylsulfone (PPSU) resin from Solvay Specialty Polymers.
The flexible precision microtubing is made with RiverTech Medical’s proprietary film cast technique, which results in small-diameter, thin-walled parts with tight tolerances. The film cast process offers advantages over traditional extrusion by achieving inside diameters down to 0.004 in., outside diameter tolerances as tight as ± 0.0003 in., and wall thicknesses as small as 0.0005 in. This tubing design is built of multiple layers of different polymers and a layer of woven wire material to provide reinforcement for the tubing wall. A fluoropolymer-based material is used for the inner tubing liner to produce a low-friction surface. A softer thermoplastic is interspersed among the wire reinforcements for flexibility.
Solvay’s Radel® PPSU is often used to provide strength and stiffness as the 0.002-in.-thick top layer. The high-performance medical-grade polymer delivers strength and melt processability comparable to competitive materials. The thermoplastic also offers high heat resistance, good hydrolytic stability, and excellent chemical resistance. It can withstand more than 1,000 cycles of steam sterilization without significant loss of properties. Radel® PPSU is also compliant with ISO 10993-1 for limited exposure, non-implantable applications.