Labels and Packaging Innovation Asia • 6 2021 -
42
Cleaning your flexo plates, anilox rolls and print stations In printing, cleaning is not just the wash-up part of the job but an essential part of keeping your flexo plates, print stations, and anilox rolls maintained and performing as intended. The use of correct solvents and wash solutions is also critical for longevity. Many cleaning methods are available. I’ll go through examples and point out which systems and wash solutions are available. It’s important to consider what inks you use and what machine may be required depending on cleaning volume. Another consideration is the proper disposal of solvents, chemicals, and waste chemicals whether in liquid form or on the rags used for washing. Can you recycle or re-claim your chemicals and what benefits does it have for your company? Proper storage of chemicals is also crucial, especially if they are flammable.
Manual cleaning When manually cleaning a flexo plate, it’s important to use the right method. This will depend on the type of plate: line, solid, text fine or large and screen. If the plate has lines or a solid image, the common method is to clean it gently with a rag. For a plate with type or a screen, a soft bristle brush and dabbing the wet areas with a lint-free cloth or rag is best. This will prevent damage to any small type or the removal of dots in your screen area. Be sure not to use solvents such as acetate. Even if it’s difficult to clean the plate, acetate can swell the text or
Author - Kane Marsh is Regional Printing Instructor Asia Pacific with MPS Systems Asia, providing training on MPS' narrow web flexo presses and specialized label applications. Automatic plate washing An automatic flexo plate washer is good for large volumes of plates to be cleaned every day. It also helps prevent plate damage and provides consistent results. The design is simple, usually with an infeed roller and nozzles to wet the plate with a plate cleaning solution. It then passes through soft bristle brushes that move from side to side cleaning the plate. The plate is then rinsed and usually hot-air dried before placed into a collection basket. Depending on how long the plate was used and how dirty it is, this process may need to be done multiple times. It’s also important to double check if the plate is dry, even with manual cleaning. Never store plates touching – they need to have a foam divider between them to prevent damage.
FlexoWash Plate Washer screen and render the plate unusable. 1. Flexo plate cleaning A number of factors are important to consider when cleaning flexo plates, as they are expensive and take time to make.
Manual plate cleaning is good during runs, or for smaller or small quantities of plates to be cleaned daily. This isn’t recommended for larger volumes.
If a damaged plate is not detected before making it to the press, the additional cost of downtime or lifting a job can decrease the job’s profit or even lose money.
The right chemical for cleaning your plate can be discussed with your plate supplier. You can use an existing plate wash that complies with any environmental requirements, or HACCP procedures your company may have in place.
NOTE* If you follow these basic steps and train your operators in manual or automatic cleaning, this can save your company thousands of dollars per year. It’s also advisable to have a monitoring program to check the plates when the job bag is returned. This must be done by an experienced person and new plates should be immediately ordered if required so they’re ready for the next run. This step will help prevent issues and ensure a smooth start up next time a job goes to press.
