Now that we’ve discussed the benefits of DTS systems, let’s talk about the “standard” method of coating screens. I use the word, “standard” because it has been so since, well, forever. If you’re reading this, you’re most likely familiar with the screenprinting process, so for those that are not, welcome. We’ll go over the very basic principles of conventional coating for new visitors and close by discussing what situations a DTS systems could work the best in. As illustrated by the graphic below, the conventional coating method involves approximately 8 steps. Keep in mind, everyone is going to do it differently and that’s perfectly fine. This graphic is meant to quickly summarize and illustrate the basics of the process.
The "Conventional Method" typically requires approximately 8 steps, but each person will do it differently.
Traditionally, you’re going to start with a diazo (or dual-cure) emulsion that requires mixing in a diazo powder before using. Once your emulsion is thoroughly mixed, you’ll want to prep and clean your screen by degreasing it and letting it dry. Now you’re ready to coat. This part can be tricky for a lot of people, so be sure to take some time to nail down your technique to ensure even coats (usually one coat per side). Check out our Youtube Channel for helpful videos on screenprinting. Now it’s time to let your screens dry. Keep in mind that dual-cure emulsions will take longer to cure. The general rule of thumb is to let screens dry for approximately 24 hours (minimum 4-6 hours before exposing).
Once you have a completely cured and dry screen, you can set up your artwork and prep it for exposure. Now, exposure times can vary greatly depending on the exposure unit you’re using. Some of the latest LED exposure units with digital auto timers for example, can expose an image in about 30 seconds. After you’ve exposed your image, it’s time to wash the excess emulsion out using a low-pressure water hose, followed by an approximately 100 PSI air hose with a nozzle attachment to dry the screen and to ensure you get all the detail out of your exposed image. Finally, be sure to check your screen for any areas that may not have been washed out completely, but most importantly, check for any pinholes.
It’s important to keep in mind that due to the frequent innovations in screenprinting technology, both methods of coating are very effective and will continue to be for the foreseeable future. The readily available nature, affordability and durability of most emulsions on the market today continue to be a source of reliability for thousands of printers worldwide. But what about these Direct-to-Screen systems? You’d be correct in assuming their large upfront expense and likely resource-heavy maintenance requirements down the road can be intimidating for smaller operations. Emulsion and scoop coaters seem to have always been there, so don’t throw away your coaters for an expensive new machine just yet. However, you’d be foolish to deny the viability of a direct-to-screen system for a larger, higher volume operation. There’s no denying that these systems are used in operations that have multiple automatic presses; these systems simply meet their volume requirements. And that’s where we’ll close this two-part article. Volume requirements. Take the time to figure out your volume requirements for the future, much like your revenue forecasts. How many screens are you currently having to burn? Do you have a dedicated employee coating and exposing your screens? How are you looking to expand your operation? There are so many factors to consider when looking to increase the efficiency of your coating process. We hope this article can give you some new insight for your business when looking at the possibility of direct-to-screen systems versus conventional coating methods. Check out this quick video from Cam Earven of Monument Limited Printing, where he gives an updated take on proper coating techniques. If you’d like more info on the direct-to-screen systems we offer, click here.