To keep up with evolving requirements of medical catheters and devices, Putnam Plastics Corp. Dayville, Conn., has developed an advanced tri-layer tubing technology that boasts significantly improved tensile and burst strength, while reducing elongation. Made with a proprietary extrusion process, the company’s new Super-Tri tubing aids in the prevention of wire lock-up in catheters where guidewires are used.
According to Putnam Plastics, a leader in advanced extrusions and components for minimally invasive medical devices, the Super-Tri technology utilizes the same material combination as traditional tri-layer tubing while providing superior performance characteristics. Often used in PTCA (percutaneous transluminal coronary angioplasty) delivery systems, tri-layer tubing typically involves a HDPE inner layer for lubricity, a proprietary middle layer for bonding, and a nylon outer layer—a construction that provides a unique combination of strength, trackability and bondability.
The new tubing is said to assist in issues that have evolved from the development of higher rated burst pressure balloon catheters. Super-Tri tubing has a 98% higher burst strength and a 750% lower elongation, compared to traditional tri-layer tubing, making it very well suited for catheters that require high-pressure balloons.
The significant elongation reduction and increased tensile strength decrease the potential for guidewire lock-up, according to the company. Says Bill Appling, dir. of engineering and assembly, “For example, a PTCA inner member where tri-layer tubing is most commonly used can now be produced with a 130% improvement in ultimate tensile strength, and 170% increase in tensile strength at yield. This product provides new options in the design of catheters for the next generation of devices where strength and size are critical.” The Super-Tri tubing technology meets the same sizing, tolerances, and material configurations as traditional tri-layer tubing.