Screen Fundamentals: A Special Three-Part Series on Scr...

Screen Fundamentals: A Special Three-Part Series on Screens

Part Three: Working with Screens. Find out how to handle your screens for longer shelf life and maximum productivity.

Now that you have a thorough understanding of the types of frames and mesh choices available to you (see Parts 1 and 2), you're ready to start working with your screens.

Initial Stretching/Inserting Mesh
You have by now made your choices regarding purchasing frames with or without mesh prestretched or inserted. Each type of frame also requires an investment in tools to get the best value from that investment.

Often you will hear someone in our industry say that they have never been happy with XYZ company frames because ÷.(fill in an excuse here). Almost every time I hear this it is because they have not made an initial investment in the tools necessary for success with the product. Kind of like a mechanic working on your car with a hammer and an adjustable wrench, he may get the job done but you won't like the results.

A partial list of recommended tools includes a tension meter, custom wrenches, spare parts, adhesives, stretching tables, etc. The good thing is that just like your dad's socket set, once you make this tool investment, it will last almost forever.

The other investment you need to make is perhaps the hardest for many of usÛTIME. Time is your most important asset and I am the first to advocate not wasting time, however the investment of your time at this point is vital.

Learn about the screen system you have invested in and most importantly learn when to tear out and replace the mesh. Millions of hours and billions of dollars have been wasted in our industry because of simple stubbornness. The comment, ÏI'll make this register if it's the last thing I do !Ó is always followed by the flushing sound of money being wasted. The reality is that a mesh tension issue is almost always causing a registration problem.

Pre-washing Mesh
All mesh has an extremely fine coat of silicone oil on each individual thread. This oil keeps the weaving machine from turning into a huge bird's nest during the manufacturing process. However, it also keeps your emulsion from adhering correctly, so the first thing you want to do with a new screen is give it a vigorous degreasing. This not only gets rid of the oil but also cleans off the crud that may have accumulated while sitting in the supplier's warehouse. The cleaner the mesh, the better the emulsion will adhere.

Next, label the screen, making note of the date you put it in inventory, and its mesh count. If your shop uses lots of mesh types, you may want to include the thread diameter too. To label the screen, lay it on your exposure unit and find a spot that will be visible during exposure. Many printers label their screens in the corner on the bottom side, but this doesn't do much good if you can't read that information easily while it's on the exposure unit.

Before you affix the label, take it into your screen storage area (the place where you keep screens before and after they're coated), and make sure that the label will be visible during storage. Now you're ready to label it.

You might want to use polycon tape for the label. This permanent tape practically requires a chisel to remove. Alternatively, if your shop does signs, you probably have vehicle vinyl handy, and this works well for labeling screens when cut into 1Ó x 2Ó squares. (If they'll stick to a truck speeding down the interstate, they'll stick to your screen.)

By the way, if this all sounds like unnecessary overkill, keep in mind that every minute a shop wastes trying to figure out the mesh count is time that could've been spent printing Û and making money.

Screen Restretching
When a screen rips, you have a question to ask yourself: What are you going to do with it? Will you throw it away, remove and replace the mesh yourself, or have a third-party company stretch and glue it for you?

The answer depends on the type of frame you're using. If it's a wooden frame, you may as well simply toss it, given the low cost of buying another. If you have a metal frame, even a static one, you can use a stretcher to apply new mesh.

Stretchers cost anywhere from roughly $300 to $3,000, depending on how big it is and how many screens it can handle at once. Alternatively, you could simply keep the ripped screens in a pile until you have enough to warrant sending them to a company that will apply new mesh for a fee.

If you have a retensionable frame, it is easy to apply new mesh in-house. This is a fairly straightforward question and is generally based on the volume of screens in your shop. Once you reach critical mass it makes sense to bring stretching in-house.

Re-Tensioning Up Close
When you purchase a retensionable frame, you have the option of buying it prestretched. I suggest buying it unstretched so that you can begin mastering the process of inserting and properly tensioning the fabric.

As you are learning the ins and outs of screens, mesh, and stretching make good use of the free education available from your vendors. Suppliers are great about spending time with new customers and helping them master the process. It's a critical part of being successful with the frame, so it only makes sense that you can handle it with no difficulties. Tools such as stretching tables also can make the job easier.

Once you have the fabric inserted and properly tensioned, it may take about 15 minutes to bring it up to its final tension. At that point, you shouldn't have to tension it again. Originally, retensionable frames were sold with the notion that printers would retension them regularly. However, as mesh as improved, the need to restretch it has changed to more of a tension monitoring function.

The previous comment may tend to make managers question the wisdom of the retensionable purchase versus a static metal frame with the right fabric and initial mesh installation. I agree, you should always question every investment. However, I firmly believe that retensionable is the only way to go for best value, control, and profitability in today's market.

Think about what a great era this is: We can bring mesh up to its ultimate tension, get a maximum open area and maximum tension, and reduce emulsion costs, thanks to the more consistent coats that high-tension frames provide. This leads to better prints, particularly with high-end, simulated process jobs, because you know how dots will resolve. Clearly, advancements in screen technology mean it's a great time to be a screen printer.