Polyethylene is a thermoplastic polymer with high ductility, chemical resistance, and impact strength. An extremely versatile material, polyethylene is available in many formulations and used in a range of applications. It is one of the most widely produced plastics in the world.
Types of medical devices that use polyethylene include:
- Molded parts
- Implanted devices
- All types of medical equipment including containers, tubing, instrumentation, and more
Engineers select polyethylenes for their low cost and versatile characteristics. Common types include:
Polyethylene (PE) with subgroups.
- HDPE (High Density Polyethylene) Density: >0.941 g/cm3
- MDPE (Medium Density Polyethylene) Density: 0.926 – 0.94 g/cm3
- LDPE (Low Density Polyethylene) Density: 0.919 – 0.925 g/cm3
- LLDPE (Linear Low Density Polyethylene) Density: 0.919 – 0.925 g/cm3
- VLDPE (Very Low Density Polyethylene) Density: 0.890 – 0.914 g/cm3
Why is it challenging to print on polyethylene substrates?
- Marking/labeling is required – yet due to the surface tension, the medical grade inks do not inherently adhere.
- The base characteristics of the substrate must not be permanently altered, so marking techniques like adhesive labels and solvent or laser etching can’t be used.
- The inks must be medical grade USP Class VI certified.
- Marking/printing/labeling must be clearly legible, dimensionally accurate, and wear resistant.
How does CI Medical overcome the challenges of printing on polyethylene surfaces?
Polyethylene cannot be printed without first pretreating the surface. CI Medical’s proprietary on-site plasma pretreatment modifies the surface tension of polyethylene to create the strongest possible bond of ink-to-substrate. Benefits include:
- No lasting changes to the substrate. After pretreatment, the polyethylene substrate it reverts to its original characteristics once the ink has cured.
- Permanent ink adhesion is achieved.
- Precise, high-quality printing is attained.