Putnam Plastics Develops New Monofilament Fiber Manufacturing Process

Dayville, Conn.-based Putman Plastics has developed a proprietary process for manufacturing custom monofilament fibers up to 0.100 inches (2.54 mm) in diameter from performance materials such as nylon and polypropylene. The company specializes in extrusions for minimally invasive medical devices. Oriented, large diameter fibers are often preferable to metals in applications that require X-ray transparency or non-magnetic properties for magnetic resonance imaging (MRI) applications.

It’s usually difficult to find large diameter medical monofilaments between 0.025 inches (0.64 mm) and 0.100 inches (2.54 mm), as medical suppliers don’t keep them in stock. Custom manufacturing these sizes requires increased extrusion volume and substantial draw down for orientation—draw down being the process of stretching the polymer for orientation to a particular size. This can present challenges in controlling diameters, maintaining strength performance and managing setup time and costs. The proprietary extrusion process Putnam has developed controls voids and diameters, according to the company, resulting in more consistent product performance.

“The convergence of minimally invasive devices and medical imaging technologies are increasing demand for non-metallic components made from high performance materials. These emerging device solutions are custom by definition,” said Ray Rilling, general manager at Putnam. “There is no off-the-shelf source for medical monofilaments with diameters greater than 0.025 inches (0.64 mm). Our monofilament lines are built for custom medical applications, with capabilities for processing the broadest range of sizes and materials for device prototypes through production.”

Putnam’s custom medical monofilament fiber capabilities range from 0.001-0.100 inches (0.025-2.54 mm) in diameter and are available in a range of materials that include polypropylene, nylon, polyester, polyurethane and thermoplastic elastomers. These monofilaments are non-magnetic, transparent to X-rays, lightweight and high-strength, thus ideally suited for tension components used in minimally invasive devices and MRI.