Screen Printing on Mesh Substrates
Is there an easy way to print these substrates? Well, not really, there is no quick solution and again there are many variables to consider.
So lets start by taking a look at the material! Typically most mesh substrates are made from Nylon or Polyester or a combination or both. Nylon will shrink and polyester will bleed when heated.
Lets start with nylon and what you can do to minimize a catastrophe! Nylon does not like heat and will shrink when heated. I recommend pre SHRINKING each garment before you take your project to the press, simply run each garment through a conveyor dryer, and reduce the heat to around 270 degrees. If you use a flash heater raise the heater up to avoid burning the substrate. Polyester is similar to nylon; a huge problem with this kind of fabric is the bleed factor. Polyester when heated will give off an invisible gas that will travel up through the layers of ink. You may have seen this on dark garments printed with light colors. Commonly called sublimation or bleeding. The color of the print can change after the print has been heat cured; the color of the garment will show through. For example if you print white on a red polyester garment the end result will be an off reddish white print. I recommend using a low bleed poly white to block out the sublimation or bleeding! Note: you can add catalyst to low bleed polyester ink. What kind of ink should be used? I recommend using Nylon ink with a Catalyst binder. YOU MUST USE A CATALYST OTHERWISE THE INK WILL NOT BIND TO THE SURFACE OF THE SUBSTRATE!
Simply add in the catalyst 10% to 15% per volume to the nylon ink, make sure to let it stand for 30 minutes before you attempt to print. The idea is to get the ink to start setting up, I will explain why as we go!
Screens, what mesh count? I recommend using a 110 to 156. The typical thought is to get the print thick as possible, not so for this process. We want to lay thin layers flashing in between! If the ink is to thick and you try to gel a thick layer, the holes will fill and the garment will start to shrink or even worse burn! So thin layers and quick flash times are going to work better. Remember the ink is catalylized and its going to accelerate the cure times!
Next set up your screen just like you would normally do. Since these substrates have holes the ink is going to pool up inside the holes. Here is what I found that works for me.
Spray down the platen with a mist adhesive, then place a pellon (test square) over the top. We are going to use the test square to absorb the excess ink that find its way in between the mesh.
Next, spray more mist adhesive on the pellon and then place the garment over the pallet as you would any other garment, make sure the substrate is secure if it moves simply re apply more mist adhesive!
Ok, magic time! Add the ink into screen, I recommend using a 70-durometer squeegee and use a 90-degree angle for the first layer with medium pressure on the stroke. We are looking to for a base layer only, its going to look very weak but thats all right. If you have filled some of the holes dont panic, they will remain some what wet. Swings the flash over, and flash for a very short time, keep an eye out for shrinkage! Remember the catalyst? Its going to help speed up the cure time.
Now, lower the screen, look through the screen and see if the entire image still lines up, if no shrinkage has occurred proceed with the second layer, use the same technique as before. After you have the second layer on the substrate I always check for a smooth consistent layer, check to see if any of the holes are filled! NOTE: if you are printing a dark color on a light substrate two layers should do, however if you are printing a light color on a dark garment the process may require a third and final layer!
Now for the tricky part, the holes are going to start to fill in if they havent already. Simply continue with the third pass, remember straight up angle with minimum pressure.
Ok, everything looks good but some of the holes are filled, not to worry. There are several ways of getting the plugged holes out! Remember the test square? The ink should have attached itself to the test square hopefully. Remove the garment from the bottom. I like to roll each side equally from the beginning or the bottom of the print. Carefully pull upward from the bottom, the holes should break free from the mesh and remain on the test square. Keep in mind the holes on the test square are going to be semi wet. Do not drag the garment across that area it will smear on the opposite side, leaving you with lots of spot cleaning! You still have some holes that are closed if they are not totally dried you can use compressed air to blow out the effected area or if they are closed send the garment down the dryer and remove the holes with a good set of tweezers. I recommend changing the test square for each print.
For printing on mesh with a lining I would recommend using a jacket clamp. It would be pointless to use a spray adhesive on these types of garments, the backing would stick and the mesh would stick to the back of the screen during the print process. Follow the same procedure as mentioned above, please keep in mind that this type of printing may leave ink on the inside liner.
Just a side note. These kinds of projects are some of the most challenging for any screen printer and it takes practice, so fear not with a little practice you to can be the master of athletic printed garments!
By: Mark Berryman