A flexographer’s guide to selecting the right plate-mounting tape and avoiding common pressroom issues
In preparation for the Great Tape Debate at this year’s FTA Forum, FLEXO magazine polled members to see what their most common tape-related concerns are.
When analyzing the results, it was clear that most flexographers experience the same challenges, including plate lift, print quality, inventory challenges, air bubbles, and difficult demount. If left unaddressed, this can lead to an enormous amount of waste and press downtime, so we consulted our team of tape experts to provide their recommended solutions.
The good news is these issues can be resolved by first selecting the right product, and then using the right application technique.
Source: R. Moran, "Mounting Materials," FLEXO Magazine, March 2023
Step 1: Choosing the right product
How does the right core construction, adhesive, and foam durometer impact my performance?
When choosing the right product for your print process, the three largest areas of product selection consideration are: core construction, adhesive, and foam durometer. It’s important to match these to the type of work you are printing.
Here’s an overview of how the categories of product selection can directly impact some of the common tape-related concerns. For example, not having the right core construction can make you prone to air bubbles or difficult tape demount. Choosing an adhesive that is too high or too low for your process can lead to plate lift or difficult demount. And selecting the best foam durometers for your operations will impact your print quality and number of sku’s (or foam durometers) you keep on hand.
Let’s start with core construction and understand how that impacts print challenges.
tesa is the exclusive supplier of two different core designs — Classic and Flex. When should you consider switching from a classic core construction design with a PET stabilization layer, to a flexible core construction with two PE stabilization layers on either side of the foam?
1. You’re using thin-walled sleeves, which respond more when expanding and contracting on a mandrel. By selecting a tape that will expand and contract with the sleeve, you’ll avoid air bubbles. Whereas a more rigid tape is prone to popping off and separating from the sleeve.
2. You’re using older, worn sleeves with a lot of dips and rough surfaces from cutting on the sleeve. Because FLEX has two PE stabilization layers, it’s more conformable and will sit in these grooves instead of on top of them. This bond prevents air bubbles from forming.
3. Your plate-mounting tape tears into pieces when you demount it. Because FLEX is made with PE instead of PET, it won’t break during demount.
How does adhesive selection impact print challenges?
The different adhesive types available in our plate-mounting tape assortment offer different performance benefits. For example, a low-tack plate-mounting tape will allow maximum repositioning and ease of demount. A high-tack plate-mounting tape will perform better in dirty conditions, but will have a more aggressive demount.
The right plate-side adhesive will prevent edge lift during printing, and tearing and stretching during demount. It's also important to choose an adhesive designed to bond to the cylinder or sleeve material you’re using to prevent bubbling on the sleeve side.
If you are struggling with air bubbles or difficult demount, this is a great time to stop, review the benefits you want out of your plate-mounting tape, and see how your adhesive aligns with that.
This is the adhesive range that is available within tesa to help make sure you get what you want out of your plate-mounting tape.
What’s durometer got to do with it?
The tape durometer impacts print quality very quickly. The rule of thumb is to use a softer tape for screens, and a harder tape for solids. You can also use tape durometer to troubleshoot print issues. One common example is using a softer tape to minimize bounce.
The more tape durometers you have, the more tapes you need to keep in inventory. In efforts to reduce inventory and maximize efficiencies, many printers are trying to streamline their tape options.
The best way to balance inventory reduction with performance on press is to utilize tesa® Twinlock self-adhesive sleeves.
Because tesa® Twinlock foam is so much thicker than plate-mounting tape, it has a larger print latitude than traditional tapes. We typically recommend using 1-2 tesa® Twinlock durometers versus your standard 3-4 plate-mounting tape options.
The special composition and thickness (1.5 mm) of our PU foam layer ensures consistent compressibility, eliminating the need for on-press machine adjustments. tesa® Twinlock also compensates for vibrations occurring on the press. This means that tesa® Twinlock can help troubleshoot bounce.
We know there’s a lot of detail that goes into selecting the best plate-mounting solution for your unique needs. That’s why our experts are here to help! Contact us today for your free consultation.
Step 2: Perfecting your application technique
Prep, mounting, demounting, and how you treat the product on press are vital pieces of the puzzle.
After selecting the right product for your purpose, it’s time to make sure your application technique is aligned.
For example, low tack plate-mounting tape requires adequate pressure to ensure a proper bond to the sleeve or plate. If you aren’t using sufficient pressure during application, you are likely to run into air bubbles or plate lift. When this happens, you should reconsider your product selection or reevaluate your processes.
Using the right product but still facing print challenges? Our plate mounting certification program might be right for you.
The tesa® Plate Mounting Certification course offers numerous benefits to flexographic print shops. By standardizing the process of mounting and demounting plates across all shifts, the course helps ensure consistent quality and efficiency. The course also provides the latest best practices and hands-on training to troubleshoot common tape-related concerns, such as air bubbles, difficult demount, and plate lift. The certification obtained after completing the course serves as a mark of expertise and continued education. Overall, the tesa® Plate Mounting Certification course improves the quality, consistency, and efficiency of plate mounting and demounting, which leads to enhanced customer satisfaction and increased profitability.
Have further questions? Reach out to our tape experts today!