Prior to the advent of using flexographic printing on corrugated substrates, the process was fraught with challenges due to a delicate material that could easily be crushed during the printing process. Printing on corrugated was limited to low-resolution inks applied lightly and simple graphics.
Flexo Printing on Corrugated
Flexographic printing has provided solutions to printing on corrugated with multicolor, higher resolution printing for high quality, complex images, and graphics. Even with the improved quality and efficiency of flexo printing, printers may experience issues when printing on corrugated. All aspects of the print process must be individually addressed and work together seamlessly for an efficient, high-quality print run.
Some of the most common issues that cause problems when flexible printing on corrugated materials include the following:
- Ink pH
- Ink Viscosity
- Printing Plates
Follow these troubleshooting tips to improve your flexible printing on corrugated process:
- Ensure ink compatibility with your substrate and process – make sure you select the proper type of ink to match the adhesion requirements of your substrate and process parameters. Ink compatibility issues may cause uneven application, spotty inkblots, or a washboard appearance.
- Evaluate ink pH compatibility – the pH of your ink must match the requirements of the substrate and will affect absorption to the substrate and drying time. Problems with ink viscosity could leave streaking, smeared images, image bleeding, and uneven color deposits.
- Match ink viscosity to substrate requirements – different substrates have varying surface tension levels, which require the correct ink viscosity for proper adhesion. Ink viscosity will affect how well the ink adheres to your substrate and could cause problems with uneven appearance, spotty ink deposits, abrasion, or foaming.
- Check printing plates prior to each print run – checking the condition of your printing plates prior to each print run is critical. Loose, damaged, worn, soft, dirty, or uneven printing plates will cause quality issues such as uneven ink transfer, washboard effects, streaking, image bleeding, and dirty prints.
How to Improve Your Flexo Printing On Corrugated Process
There are some things you can do when troubleshooting issues with flexo printing on corrugated materials. Follow these tips to improve corrugated printing flexo applications:
- Eliminate contamination – check your cartridges for dried ink and keep all image carriers in good condition. Control airborne contaminants and check for plate swelling.
- Follow press maintenance programs – make sure you have a thorough press maintenance plan, including preventive maintenance and system checks to follow at the start of each job.
- Check for worn gears – check gears regularly, clean, and lubricate them to maintain optimum working performance and prevent printing quality issues.
- Monitor surface tension – consistently monitor surface tension, check all working parts and increase pressure accordingly.
- Maintain image carrier – be sure not to use harsh cleaners are solvents that could damage or swell plates.
- Use the right anilox roller – be sure to use an analog what the right amount and depth of cells to hold and transfer ink at the appropriate rate.
- Choose the right type of ink – be sure the ink matches your printing and substrate requirements with the right pH level, viscosity, and other characteristics.
- Allow proper drying time – be sure to allow the correct drying time based on your ink selection at substrate requirements. Hurrying drying can undo all of the preparation performed for the perfect printing process.
If addressing the most common causes of quality issues and following this checklist for troubleshooting flexo printing on corrugated and you are still having issues, reach out to an experienced flexo printing and finishing expert.
Tamarack® Products is a leading manufacturer of specialty equipment used with flexible printing presses for high-quality printing and finishing on a variety of substrates. We offer in-line and off-line finishing solutions with flexo press efficiency and flexibility. Contact us to learn more about improving your flexo printing on corrugated process.