Flexographic printing products are like cars. And before you raise your brows, hear us out.
If you buy a new car, you want to take good care of it because you just spend tens of thousands of dollars on it. You change the oil every 3,000 miles, you undercoat it -- the whole nine yards. If you take good care of that car, it will last you a lot longer than if you only put in minimal effort to keep it running.
Flexo printing equipment follows the same principle.
Repeated use on the press, cleaning, and exposure to volatile chemicals will eventually weaken and damage your flexo printing sleeves - affecting the quality of your prints and therefore your company’s bottom line. Use these tips to keep your flexo equipment up and running for as long as possible.
Take Good Care of Your Flexo Print Sleeves and Plates: Flexo Print Maintenance
Elastomer flexographic printing sleeves are particularly efficient and durable against abrasion, aggressive inks, and solvents.
On the other hand, printing products manufactured from photopolymer, while valuable for certain types of jobs, are more vulnerable to:
Whatever your choice, elastomer and photopolymer sleeves and plates are not invincible. They require some common-sense (and not so common-sense) care tactics while cleaning excess ink after one print job and stowing away for the next.
Here are some tips for the proper cleaning, maintenance, and storage of your flexo sleeves.
SPEED IS KEY
Although it might be tempting to take a break after a long printing session, waiting even a little while to begin cleaning can cause damage to your print sleeves and cylinders.
You must clean the sleeves and cylinders immediately after they’re removed from the press before the ink dries and hardens.
CHOOSE THE RIGHT CLEANING SOLUTION
Give your flexo sleeves and plates a good wash. Not so fast, though. It’s not a matter of just splashing on some ink-dissolving chemicals.
Different cleaning solutions work best with different types of inks. (And some don’t require volatile chemicals at all.)
- Water-based inks
- Use mild soap and water
- Isopropyl or industrial alcohol works for most rubber types
- Rinse with water
- Solvent-based inks, oil-based inks, UV-based inks, and electron beam-based inks
- Use a solvent appropriate for your ink type or an approved nonvolatile wash-up solution
Remember: Your rubber print sleeves are durable, but they do have a soft surface. So, harsh cleaning tools and methods can scour away the rubbery surface of both elastomer and photopolymer print products. Avoid using rough materials, such as metal or wire, when cleaning your image carriers.
Recommendation: Use a soft-bristled brush to gently remove excess ink and debris. Natural-hair brushes work well and make it easy to clean gently and thoroughly.
Let air work it’s evaporating magic. However, we don’t recommend using an air hose, as contaminants in the lines may attach themselves to your drying sleeves or plates.
The goal is to keep the surface clear of foreign debris that could negatively affect printing quality.
Wait at least 4 hours before storing cleaned sleeves and plates to ensure complete evaporation of solvents and other liquids. Wrap them in a black-backed paper or film which will block ozone and UV lights that could change their physical properties.
Storage temperature and conditions are critical:
- Never above 90˚ F
- Never below 32˚ F
- Little to no humidity
- Far from things that emit ozone, like electric motors and lights
Temperature is a big factor in plate/sleeve expansion and contraction. When the temperature rises, the polymers expand, and even the expansion of a thousandth of an inch can cause print registration issues. Same goes for contraction -- when sleeves get too cold, they contract, which can affect the quality of the print.
Store sleeves upright. Laying them on their side could damage the printing surface. Use a cushion if it must be placed horizontally.
Nickel/Nickelok sleeves should always be stored standing on a cushioned surface to protect the ends from damage.
Protect Your Investment by Properly Maintaining Flexo Sleeves
Failure to properly maintain your flexo print sleeves, plates, and cylinders results in preventable damage that’ll shorten their lifespan and forces replacement. At the very least, inadequate cleaning and storage can leave debris that’ll diminish print quality.
But if you take proper precautions and employ the right products for the job, your flexo products will last and create quality prints every time.
Editor's note: This blog was originally published on November 22nd 2018, and was updated in February 2021.