Tresu Group has developed a multi-color flexo printing unit for applying patterns to nonwoven disposable sanitary napkins. Customized to the specifications of the production line, the printing unit comprises up to four water-based colors, a hot air dryer and, at the embossing point, a register guidance camera. It is capable of printing on nonwoven materials between 15 and 22gsm, especially pre-perforated PE polymers. The unit also offers a compact footprint and an operator-friendly design.

Located at point of embossing, the register guidance system ensures synchronization of the printed pattern with the crease in the center of the napkin, at speeds of up to 400 meters per minute (approximately 2000 pieces per minute). Using the converting machine interface signals as point of reference, the control module influences the servo motors to ensure accuracy is maintained on-the-fly throughout the production run. Servo drives ensure automatically controlled, precise print speed and ink flow, so that operation without in-house flexo experience or handling is possible.

Allan Sander, vice president, Tresu Solutions, comments: “Consumers are increasingly seeking assurance about the quality of their products, and research has shown that there is stronger loyalty to napkin brands with recognizable printed designs such as icons or logos printed on the fabric. Tresu’s customized printing integration system enables the personal hygiene industry to achieve this, while maintaining a cost-controlled, flexible, single-pass operation.”   

The integration unit includes Tresu’s F10 iCon ink supply system with automatic cleaning, to constantly feed the printing units and maintain optimum viscosity, temperature and pressure. Sealed, pressure-controlled chambered doctor blade systems enable direct, foam-free transfer of ink or coating to the anilox rollers, ensuring a consistently clean printed image.

The system is optimized for fast job changes. A control system stores and, in the case of repeat jobs, instantly recalls job recipes, so no re-entry of ink and calibration data is needed. At the installation stage, the Tresu technical team works with the customer to build a unique database of recipe settings for each job, including, among others, impression settings, print levels, flow rate, air velocity, temperature and register coordinates.

The ability to seamlessly integrate the printing operation into the existing converting and assembly line means that customers can avoid the costs and lengthy lead times associated with outsourcing.