Guidewire Encapsulation

Guidewires commonly fall into one of four categories: coiled wires, filaments (stainless steel, nitinol, or other memory metals), sheathed wires, and coated wires. Coated wires provide a critical hydrophilic outer layer over the wire to facilitate atraumatic insertion during vascular procedures. The increased lubricity of coated wires reduces the potential for kinking or buckling when maneuvering within the vasculature. Coated wires are designed to achieve an optimal combination of flexibility and stiffness.

For endoscopy applications such as ERCP, guidewires are often sheathed or encapsulated in a polymer heat shrink to accomplish a similar function as coated wires. Zeus PTFE heat shrink over guidewires, for example, gives these components increased lubricity and provides medical professionals with the ability to track the wires visually using striping.


PTFE Spiral Stripe Heat Shrink

Zeus PTFE spiral stripe heat shrink gives physicians the visibility they need to perform a variety of endoscopic procedures from colonoscopy to bronchoscopy to ERCP. Spiral striped heat shrink over the guidewire allows surgeons to not only be sure of guidewire location but also track its rotation within the body.

Zeus PTFE spiral stripe heat shrink is available in a variety of colors and stripes per inch:

Spiral Stripe PTFE Heat Shrink Colors
Typical (preferred) Less Common
black brown
blue gray
green orange
lime green pink
natural purple
Number of Stripes Per Inch Possible
Number Of Colors Stripes Per Inch Possible
2 4-8
3 9-16

Patterns involving four stripes using only two different colors are also possible in order to achieve a higher stripe density per inch than would be possible using only two colors.

Sub-Lite-Wall™ Heat Shrink

Zeus Sub-Lite-Wall™ PTFE heat shrink offers the thinnest walled heat shrink extrusions currently available. Designed to produce wall thicknesses of 0.005″ (0.127 mm.) and below with tolerances of ± 0.0005″ (0.0127 mm.), these heat shrinks help minimize guidewire profiles by keeping the encapsulation thickness to a minimum. PTFE is an excellent resin for guidewire encapsulation, as it is biocompatible, chemically inert within the body, and can be sterilized by autoclave and EtO. PTFE is also a USP Class VI approved resin.

Expanded ID Recovered ID Wall Thickness
in. mm. in. mm. in. mm.
Sub-Lite-Wall™ Heat Shrink
0.011″ to 0.087″ 0.279 to 2.210 0.005″ to 0.055″ 0.127 to 1.397 0.002″ to 0.005″ 0.051 to 0.127
Heat Shrink
0.018″ to 0.120″ 0.457 to 3.048 0.006″ to 0.0394″ 0.152 to 1.001 0.004″ to 0.012″ 0.102 to 0.305

Zeus is able to limit the tolerances on expanded and recovered dimensions for our spiral stripe heat shrink.

Guidewire Tip Forming And Fusing


To complete the guidewire, manufactures often modify guidewire tips (also known as tipping) for specialized performance characteristics. For endoscopic guidewires, tips are routinely encapsulated with a hydrophilic urethane or another tailored polymer. Zeus FluoroPEELZ™ peelable heat shrink placed over the thermoplastic urethane (TPU) provides an easy way to capture and contain the tip material during TPU reflow. Afterwards, the recovered FluoroPEELZ™ is easily and safely peeled away leaving a smooth finish to the guidewire tip.