The Screen Printing Technical Foundation has been comparing methods of applying tension to screenprinting screens. The goal is to find a method which can produce screens which hold high tension for long periods of time. Three methods were tested, Pre-loading, Vibration, and Pulsed Tensioning. 

In pre-loading, a weight is applied to the screen during tensioning and prior to setting the screen in a frame. The hope is that the resultant stretching will occur at this point rather than during printing. No real advantage was found when this method was applied and some disadvantage was noted. This is not recommended. 

Vibration tensioning assumes that by vibrating a screen during tensioning, molecules in the strands will be aligned in a stronger fashion. Applying vibration for five minutes was shown to be slightly better than normal staged or rapid tensioning, but a ten minute application showed even better results. 

Pulsed tensioning applies a greater tension than the target for a short time, followed by a lesser tension. As the process is repeated, the molecules in the strands are hypothesized to orient themselves in successively stronger patterns. This method showed the longest tension maintenance period, especially if the pulses were held for ten minutes. 

Author: Dennis Hunt, SPTF
Source: SGIA Journal, Q1 2000, p. 34-36.