Sleeves & Adapters
In order to make the best decision on plate mounting sleeves and adapter selection, we need to ask the following questions:
Is there a need for adapters? The answer will come from the repeat sizes to be used. If the repeat list is widespread, then it is highly recommended to use adapters, as they will help to keep the sleeves’ wall thickness under control. Otherwise, the overall result will be a very heavy, thick wall sleeve inventory. Another benefit of using adapters is that it will help with the overall sleeve cost.
What type of adapter is needed? To answer this question, we need to dig a little more and determine the following: What is the target press speed? When the target press speed is high, press vibration is more prevalent. In these cases, the use of high modulus carbon fiber (HMCF) adapters is the best option out there, because of the vibration dampening characteristics that result in minimal bounce and help to maintain good print quality without having to slow down the press. If the target press speed is not high, then a standard adapter construction will work.
What is the best air distribution? Now that it is decided which type of adapter is needed, it is important to decide on air distribution for loading the top sleeves onto the adapters. There are basically two different ways to distribute the air to load the sleeves:
- Standard four-to-eight leading air holes (depending on the final outer diameter) and downstream air hole configuration
- Incorporation of a breathable metal ring for maximum air distribution to the adapter’s surface. This particular choice needs up to 90 percent less air volume and helps to reduce the noise to less than 60 dB as compared to more than 85 dB with the standard air hole configuration. The overall result is a better, faster, safer and easier mounting operation
What is the configuration of the air source of the printing? Depending on the press specifications for pneumatic applications, the press air source can be either flow through—where the air flow is transferred from the mandrel through the adapter—or a direct air connection to the adapter.
What type of sleeves can be chosen? There are two types of plate mounting sleeves in the marketplace:
- Hard surface sleeves
- Plate mounting with a 0.015-in. or a 0.020-in. cushion tape
- Surface more resistant to cuts
- Plates can be mounted with different compression modulus tapes
- Compressible sleeves
- Plate mounting with a 0.005-in. double-sided tape or self-adhesive (there can be tape savings here)
- Highly stable compressible surface with consistent printing results
- Soft, medium and firm hardness options
- A surface less resistant to cuts (but there are several tools out there that aid when cutting)
What is expected from the sleeves and adapters overall? In a word—Quality! In several words:
- A sleeve that is temperature and humidity resistant, durable and with more structural integrity
- A sleeve with all of the above, improved for superior dimensional stability over time and tougher sleeve construction
- A sleeve with all of the above that is easier to mount and has bounce reduction properties
“The advantage of a textured plate in flexible packaging is well documented, and the structure of flat top dots makes both theoretical and practical sense for ensuring plate-to-plate consistency and stable color on press.”
Lead Times & Customer Service
Manufacturing of sleeves and adapters takes time. Lead times become especially important when there is a new design size to be printed or when there is a need to receive sleeves quickly to meet deadlines. In even more critical situations, a rush program can provide the same quality sleeves and adapters even faster.
A dedicated team to assist with obtaining the correct design specifications of a custom-made, finished product, which depends on the press and design specifications, is an important factor to consider.
In Summary
- Generally speaking, choose adapters with the best air distribution that will make mounting easier, better and faster
- When running jobs on a high-speed press, choose high modulus carbon fiber adapters in combination with sleeves that possess superior dimensional stability
- When not running a high-speed press and printing jobs prone to bounce, choose standard adapters and sleeves (hard or compressible) with bounce reduction properties
- If the jobs require high tolerances, go for sleeves with superior dimensional stability
- If the jobs require standard flexo tolerances, select a sleeve that is temperature and humidity resistant, durable and with structural integrity
- Choose either hard or compressible sleeves and stick with that choice
- When choosing compressible sleeves, it is better to choose one hardness for all than to choose a mixture
- Select sleeves and adapters with the quality, lead times and customer service support that will assist in getting through the day-to-day battles
About the Authors: PJ Fronczkiewicz and Felipe Garcia are North American product managers for Flint Group printing plates and sleeves, respectively. To learn more about Flint Group’s nyloflex flexographic printing plates or rotec sleeves and adapters, contact Terri Stewart at 704-504-2628.