Industry News
Jan 09,2026
What are the differences between medical PTFE tubing and medical PI tubing?
In the design and manufacturing of minimally invasive medical devices, the choice of catheter material directly determines the product's performance and clinical safety. Medical PI tubing (polyimide tubing) and medical PTFE tubing (polytetrafluoroethylene tubing) are currently the two most widely used high-performance polymer materials in interventional medicine. Although both possess excellent biocompatibility, they differ significantly in mechanical properties, processing techniques, and specific applications.
As a professional supplier of medical-grade tubing, LINSTANT is committed to providing high-performance material solutions for global medical device development. Our business scope covers a comprehensive product line from basic extrusion to complex reinforced structures, including extruded single/multilayer tubing of various sizes, single-lumen/lumen tubing, single/double/triple-layer balloon tubing, coil/braided reinforced sheaths, as well as specialty engineering materials PEEK/PI tubing and various surface treatment solutions.
I. Comparison of Core Material Properties
To understand the differences between the two, we must first start with their physical and chemical properties:
1. Medical PI Tube (Polyimide)
Medical PI tubes are renowned for their extremely high strength and extremely thin wall thickness:
High Strength and Hardness: PI material has extremely high tensile strength, providing excellent compressive strength and kink resistance.
Extremely Thin Wall Thickness: It can be processed into micro-tubes with a wall thickness of only about 0.01mm, which is crucial for interventional procedures requiring passage through extremely fine blood vessels.
High Temperature Resistance and Chemical Stability: It maintains structural stability under various sterilization environments.
2. Medical PTFE Tube (Polytetrafluoroethylene)
PTFE is known worldwide for its "slippery" properties, being one of the solid materials with the lowest coefficient of friction:
Extremely High Lubricity: The ultra-low friction of the inner surface of Medical PTFE Tube makes it an ideal choice for guide wires and liners in delivery systems.
Excellent Flexibility: Compared to medical PI tubes, PTFE is more flexible and easier to bend.
Non-stickiness: It adheres to virtually no substances, effectively preventing thrombosis.
II. Main Differences Between Medical PTFE Tubes and Medical PI Tubes
Physical Strength and Support: Medical PI tubes possess extremely high tensile strength and rigidity, exhibiting metal-like physical properties, providing excellent resistance to kinking and structural support. In contrast, Medical PTFE Tube products are softer and more flexible, but are prone to deformation under pressure.
Wall Thickness and Dimensional Accuracy: In interventional medical devices requiring extremely miniaturization, medical PI tubes offer significant advantages. They can be processed into extremely thin tubes with a wall thickness of less than 0.02 mm while maintaining strength. Medical PTFE tubes, due to material limitations, typically have thicker walls, making it difficult to achieve the same level of strength in ultra-thin specifications.
Surface Friction and Lubrication: Medical PTFE tubes possess the lowest known coefficient of friction among solid materials, exhibiting natural super-slippery properties, making them ideal as liners for delivery systems. While medical PI tubes have a smooth surface, their friction is relatively high, usually requiring the application of a hydrophilic coating to improve their slipperiness.
Bonding and Composite Processing Capabilities: Medical PI tubing has good chemical polarity, making it easy to bond and composite with medical adhesives (such as UV adhesives) or thermoplastic elastomers (such as Pebax); Medical PTFE Tube tubing, on the other hand, has extremely strong non-adhesive properties and usually requires complex sodium curing treatment or LINSTANT's PTFE surface treatment before being composited with other materials.
Visual Characteristics and Transparency: Medical PI tubing typically exhibits a characteristic amber, golden yellow, or dark brown color; while medical PTFE tubing usually appears as an opaque milky white or translucent waxy appearance.
III. Differences in Clinical Application Scenarios
Due to their different properties, these two types of medical catheters play different roles in interventional medical devices:
Applications of Medical PI Tubing
Due to its excellent electrical insulation properties and rigidity, it is often used as a reinforcing layer for electrophysiological catheters, microcatheters, and as a support cannula in cardiovascular interventional devices. When it is necessary to pass through narrowed lesions, the pushing force provided by medical PI tubing is unmatched by other materials.
Applications of Medical PTFE Tubing
Primarily used as a catheter liner. In multilayer composite catheters, PTFE, as the innermost layer, ensures smooth passage of guidewires or other instruments through the catheter lumen, reducing operational resistance.
IV. How to Choose the Right Catheter Material for Your Needs?
During the development process, the choice between medical PI tubing and PTFE tubing depends on your design goals:
If your device requires an extremely small outer diameter and a very large inner diameter (i.e., thin-walled), while also demanding extremely strong support, medical PI tubing is the preferred choice.
If the core requirement of your device is smooth delivery of internal instruments, then a PTFE liner is indispensable.
Composite Solutions: Modern high-end microcatheters typically employ a "combination of inner and outer layers." LINSTANT can provide customized coil/braided reinforced sheaths, perfectly integrating PTFE liners with medical PI tubing or other reinforcing layers.
LINSTANT consistently focuses on the cutting-edge needs of minimally invasive medicine, helping medical device manufacturers achieve more precise and safer clinical procedures by providing precision-engineered PEEK/PI tubing and multilayer/multi-lumen tubing.