There are a number of reasons why your screen is sticking to the shirt during the printing process. The most common cause is the over-flashing of the ink. Either the flash temperature is set too high, the amount of time under the flash-cure unit is too long, the distance between the platen and the flash is set too close, or a combination of these could be the cause.
Flash curing is only supposed to gel the ink so that other colors can be printed on top without mixing the flashed color. The ink is not supposed to cure completely but just be gelled to the touch. If the ink is overheated, it will melt the ink, and the screen can get stuck to it at the next pass.
On the other hand, if the ink has been flashed but not completely gelled, it is possible to have the screens stick because it has been under-flashed. Try adding a few more seconds to the flash time to see if that may be the issue.
Another cause could be the off-contact setting (off-contact gap pictured below). If the screen has low tension, it could require additional off-contact. If the ink layer is on the thick side, it also may need more off-contact. In any case, the screen should peel away from the substrate after the squeegee has passed over the image. If not, additional off-contact is required.
—International Coatings Company
