Flexo Printing for Folding Cartons in Transition - Process Automation, Waste Reduction, and Improved Print Quality

Folding cartons and flexographic printing on the rise.

Label and packaging printing are growing globally at an average of approximately 2.3 % per year. The main driver of this growth is folding carton printing. They are sustainable, made from renewable resources, highly recyclable, and enjoy a very positive image among consumers.

In the realm of folding carton printing, flexographic printing is seeing the most significant growth among all analog printing methods. The market share of folding cartons produced using flexographic printing stands at about 15 %.

About half of it is liquid packaging. The advantages of flexographic printing lie in the ability to produce packaging in an inline production process- from the cardboard rell to the die-cut carton - in a single process. Additionally, the printing machines are flexible and can be configured for complementary printing and finishing technologies or other technologies such as inspection.

The primary applications of flexographic printing for folding cartons are high volumes and large formats and , such as pizza boxes, liquid cartons, or beverage packaging like multipacks.

Criteria for quality and waste: plate mounting, and impression setting

The quality of today's flexographic printing is similar to offset printing or other printing processes. However, it requires correct machine settings and proper operation. Key quality factors include plate mounting and of the flexographic printing form. Precise plate mounting ensures optimal registration quality, while the print result is significantly influenced by the impression setting. Excessive pressure leads to squased dots, while insufficient pressure results in inadequate ink coverage.

When manually adjusting a flexographic printing machine, the operator sets it in motion at low speed, checks the print image, adjusts the plate alignment and impression settings of the cylinders until everything aligns. The material that runs through the machine during this process is waste.

Quality control and waste reduction with Intellimatch – how does it work?

The new offline scanner, Intellimatch, enhances the quality in flexographic printing and avoids a significant portion of the usual waste. It contributes to cost reduction and conservation of resources, and thereby contributing to sustainability. Intellimatch conducts comprehensive checks for roundness, surface quality, and plate contamination, enabling immediate rectification of defects for flawless print results.

After mounting the sleeves with flexo plates on the printing form cylinder, Intellimatch scans and measures them. The scanner identifies the cylinder's roundness, its surface, and potential damages on the plate, many of which would only be noticeable to the naked eye after a test print on the machine. Any possibly soiled areas are also identified and can be addressed before the cylinder is mounted in the printing press. Using only flawless printing plates and sleeves in the press significantly reduces the amount of waste generated during printing operations.

Flawless printing with verified sleeves and optimal printing pressure

Intellimatch measures the topography of the printing plates. The collected data serves as the basis for optimal printing pressure in each printing unit. Thus, during job changes, Intellimatch ensures consistent print quality and significantly reduces waste, all without requiring operator intervention. Sleeves with mounted printing plates receive a data matrix code, and their values are stored on a server or in the cloud. The integrated code reader on the printing press recognizes the inserted flexo sleeve and retrieves the values for optimal impression settings, calculated using algorithms, from the database

Push-to-Stop in flexographic printing – fully automatic job change at full production speed

The combination of the new Boardmaster with HEIDELBERG Web Carton Converting's Intellimatch scanner enables fully automatic job changes in flexographic printing, reducing waste by up to 90 % compared to previous methods, even during ongoing production. The machine switches printing units automatically at full production speed (up to 600 meters per minute) and a maximum of 10 meters of waste for the next job.

Based on scan data from Intellimatch, the correct impression is set in the shortest time without operator intervention, ensuring consistent print quality. Intellimatch forms the foundation for fully automatic job changes in flexographic printing - operating at full production speed and without the need for an operator.

In summary, the integration of Intellimatch revolutionizes quality control in flexographic printing and enhances efficiency in packaging printing through increased process automation, waste reduction, and improved print quality.

Are these details of interest to you?

You can find more about the offline scanner Intellimatch and the Boardmaster here: The new Boardmaster | HEIDELBERG.

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