Predicting the Behavior of Screen Printing

A novel mathematical model is presented of the liquid transfer process encountered during screen printing, enabling the prediction of the volume of liquid removed from a mesh and printed on a substrate with reasonable accuracy. It is based on the key assumption that free surface effects dominate and the printed liquid is pulled out of, rather than flows from, the mesh. The model is validated against an extensive range of benchmark data from both on-and off-screen printing trials. The agreement is found to be remarkably good. In addition, the model is able to offer considerable insight to practitioners and liquid manufacturers alike-a key result being that the screen printing process can be made essentially independent of many of the set-up parameters in the operating range adopted by most practitioners.