Fluoropolymers are fluorocarbon-based polymers characterized by a high resistance to solvents, sterilization, alcohol, and heat. Because of these properties, fluoropolymer substrates are excellent for giving medical devices a permanent "non-stick" surface that is resistant to wear. Unfortunately, these properties also prevent ink from adhering to the surface – which makes fluoropolymer pad printing a challenging process.
Medical components that use fluoropolymers include:
- Molded parts, such as handles
- All types of implanted medical devices including short term, long term, and permanent implants
Engineers select fluoropolymers for their lubricous surface and corrosion resistance. A few types include:
- PTFE (Polytetrafluoroethylene)
- PFA (perfluoroalkoxy alkane)
- FEP (fluorinated ethylene propylene)
- ETFE (ethylene tetrafluoroethylene)
- PVDF (polyvinylidene fluoride)
- ECTFE (ethylene chlorotrifluoroethylene)
- ePTFE (expanded polytetrafluoroethylene)
Why is fluoropolymer pad printing so challenging
- Marking/labeling is required – yet due to fluoropolymers' low coefficient of friction, medical grade inks do not inherently adhere.
- The base substrate characteristics must not be permanently affected, so adhesive labels and etching techniques cannot be used as an alternative to ink markings.
- The inks must be medical grade, USP Class VI certified.
- Markings must visually clear and dimensionally accurate.
How does CI Medical overcome the challenges of printing on fluoropolymer surfaces?
Fluoropolymers cannot be printed without first pretreating the surface. Proprietary on-site plasma pretreatment allows CI Medical to modify the surface tension of fluoropolymer surfaces to create the strongest possible bond of ink-to-substrate. Benefits include:
- No permanent changes to the substrate’s properties. While the surface of the substrate is temporarily altered, it reverts to its original characteristics once the ink has cured.
- Permanent ink-to-fluoropolymer adhesion
- Precise, high-quality markings
In addition to standard medical grade inks, we can also mark fluoropolymer substrates with our proprietary Radiopaque™ inks. CI Medical takes on the difficult challenges that other pad printing companies cannot! Contact CI Medical to discuss printing and marking on your medical devices.