Medical technology

Pad printing in medical technology is usually carried out under cleanroom conditions. In addition to plastic components such as syringes, device housings, fixators, and microtiter plates, flexible stoma bags and catheters are also printed.

Cleanroom

Pad printing is used in the medical industry to apply markings or scales to products. Since these products often come into direct contact with the human body, they must be processed under controlled cleanroom conditions to avoid contamination. Depending on the application, the printing process must meet specific cleanroom standards, such as ISO 14644-1 Class 7 or 8 for packaging areas or Class 5 or 6 for sterile products. The pad printing machines must be adapted accordingly based on the cleanroom classification.

In most cases, the following adjustments are required:

• The compressed air must be filtered, or the exhaust air from the compressed air must be collected and directed out of the cleanroom.
• Protective devices on shafts and guides prevent potential contamination of the printed parts.
• The machine should be designed with as few edges and corners as possible. Smooth, easy-to-clean surfaces are essential.
• Gaps and screw heads can be covered to prevent dirt accumulation.
• The sides of the machine should be flat and free of texture.
• Worktables for comfortable operation should be made of plastic rather than wood.
• The base plate of the pads must be made of metal, as wood is unsuitable for this application.

Pad Printing on Catheters

One particular challenge in medical technology is printing on catheters. The wide range of sizes, lengths, and diameters, as well as the handling of flexible tubes, complicates the process. Urinary catheters, vascular catheters, cardiac catheters, peritoneal catheters, epidural catheters, and gastrointestinal catheters often require special markings or scales for positioning.

Since a narrow, elongated print image is necessary, a transverse doctoring system is often used. In this system, a small ink cup moves continuously across the long print area. If a single-sided print is sufficient, it can be implemented efficiently using a dual-holder alternating operation. Printing 360° around the catheter is more complex and can be achieved either through a rolling process or with a rotating unit.

Further Requirements

The requirements in medical technology are diverse. Fixators are usually printed with scales and various colored symbols, which can only be achieved in a single pass using a multi-color pad printing machine (ML). In contrast, stoma bags require a high-speed production process, which is why fast modular pad printing machines are used in this area.