PTFE Monofilament

Traditionally, many catheter manufacturers have opted for PTFE-coated stainless steel wire as the mandrel of choice for most catheter builds. While stainless steel provides good mechanical strength, the thin PTFE coating applied over the stainless steel wire can be prone to flaking during mandrel removal, potentially compromising the build. Extruded PTFE monofilament, on the other hand, avoids this issue and still provides sufficient compressive strength for a wide range of catheter designs. PTFE’s ability to be extruded with precise tolerances down to ± 0.0005” (± 0.0127 mm) helps ensure consistent IDs of the finished catheter, and its naturally smooth non-stick surface helps facilitate mandrel removal at the end of construction.

Glass-Filled PTFE Monofilament

For catheter designs that require higher PIC count braiding, such as neurovascular catheters, the mandrel used during construction must be capable of withstanding the additional compressive forces imposed by the braid. This higher compressive strength can be achieved by compounding glass particles into the PTFE resin prior to extrusion. The result is a mandrel with enhanced mechanical properties, capable of supporting the most complex catheter builds and braid patterns.

XpanCore™ Mandrels

Many catheter designs now use metallic laser-cut hypotubes due to the advantages they offer over traditional braided or coiled shafts, such as higher strength, kink resistance, and more customizable flexibility profiles. However, manufacturing hypotube assemblies can introduce additional time and process complexity, particularly when integrating liners within the inner diameter (ID) of the hypotube.

XpanCore™ mandrels were engineered specifically to address these challenges. Designed to expand when heat is applied, XpanCore™ mandrels are advanced processing aids that help simplify the construction of hypotube assemblies by alleviating issues with liner sizing, placement, and adhesion. During processing, XpanCore™ mandrels expand to help secure the liner against the ID of the hyptoube without the need for pressurized systems or other complex techniques. This can help speed production, improve yields, and reduce common manufacturing challenges, such as liner tearing, incomplete bonding, leaks, and delamination that may compromise device performance.

Other Mandrel Options

In addition to PTFE and XpanCore™ mandrels, Zeus can produce mandrels from other materials, including FEP, PEEK, PEEK Glide™, and PFA, as well as in customizable profiles. Contact us today to learn more.