Thermal Transfer Printing on Tyvek® for Medical Packaging
Case Study
Challenge
A manufacturer of packaging for single-use medical products needed a reliable solution for marking medical packaging. Product information and barcodes are printed directly onto the packaging material to support the secure traceability of medical devices. The customer used an industrial printing system with flat-head thermal transfer technology for labeling. With the packaging material used previously, this printing process had operated reliably over a long period with high print quality. However, as part of a material changeover, the company switched to Tyvek®-based packaging material - a material developed by DuPont that is frequently used for sterile medical packaging. After the change, however, significant printing issues arose when using thermal transfer printing on this material. The wax-resin ribbons previously used for flat-head printers were no longer producing satisfactory print results.
Typical Problems Included:
- Poor ink coverage
- Poor adhesion of the print
- Inadequate barcode quality
- Blurry print images
Since permanent and legible labeling of medical packaging often is required by regulation, this posed a significant risk to production safety.
Problem Analysis - Why Tyvek® Is a Challenging Material for Thermal Transfer Printing
Tyvek® has a fibrous plastic structure that differs significantly from traditional label materials. This surface structure significantly affects ink transfer during thermal transfer printing.
The standard approach in thermal transfer printing - low print speed and high print energy - did not yield better results in this case. Instead, it tended to result in:
- Blurry print images
- Uneven ink transfer
- Reduced print quality
Therefore, an alternative approach was developed for barcode printing on Tyvek®-based packaging material.
Solution: Near-Edge Thermal Transfer Ribbon in Wax-Resin Quality
After several tests, the combination of a near-edge thermal transfer printer and a specially designed wax-resin ribbon proved to be a suitable solution for this specific use case.
The Near-Edge wax-resin ribbon K 708 was used.
The key factors for consistent print results on Tyvek®-based packaging material were:
- Use of a near-edge printing system
- Print speed of at least 177 mm/s
- Medium print energy
- Use of a Near-Edge wax-resin thermal transfer ribbon
Near-edge technology enables particularly fast and precise ink transfer. This made it possible to achieve clear barcode printing on this material. The new printing solution offered several technical advantages.
Technical features of the dolution in the tested use case:
- Excellent adhesion to Tyvek-based packaging material
- High contrast and clear barcode quality
- High print speed with consistent print quality
- Good abrasion resistance of the print image
- Protection of the print heads due to moderate printing temperatures
Implementation
For the implementation, the existing printing process was adapted and converted to a near-edge thermal transfer printing system.
Results
After implementing the new solution, the customer was able to achieve consistent labeling of medical packaging and reliably perform thermal transfer printing on Tyvek®-based packaging material, the K 708 ribbon is now used as standard for this application.
Conclusion
Tyvek® is one of the more challenging materials in thermal transfer printing. This case study demonstrates that consistent, high-quality print results are achievable through the right combination of near-edge printing technology, optimized print speed, and a suitable wax-resin ribbon.
For manufacturers who need to label medical packaging on Tyvek®, we can offer a reliable solution.
