Correct and careful handling are the two most important factors in maintaining the life of a screen. Careless handling can destroy a screen's usefulness within seconds and is a major cause of premature screen failure. Another cause of screen failure is improper printer set-up, which leads to bagging of mesh.
Proper tension is critical in achieving consistent, precise prints over long production runs. A properly tensioned screen will give excellent peel characteristics at a minimum snap-off setting (Snap off, breakaway, or screen height are terms for the undeflected distance between the screen and the substrate).
Minimum snap-off settings reduce screen stretch and subsequent pattern misregistration.
Newton gauges measure deflection within a specific amount of area encompassed within the footprint of the gauge while an interior spring applies pressure against the mesh.
Therefore recommended Newton's per Centimetre (N/cm) readings for specific mesh are valid for any frame size.
Examples of maximum recommended tensions
The TETKOmat is a portable compact mechanical tension measuring device for accurate and consistent measurement of a screening media.
It has a simple, quick direct reading measuring systems with equivalent values for Newtons per centimetre (N/cm), printed on its base.
Screen tensions are expressed in N/cm, which relates the amount of force required to provide a fixed deflection. Uniformity of tension will help ensure uniformity in precision printing applications.
The TETKOmat measurement readings are easily related to the recommended N/cm figures. The high sensitivity of the TETKOmat allows measurement of tension variations within a screen regardless of frame size. This enables the screen make to correct or change tensioning techniques to achieve the most uniformly tensioned screen.
Correct and uniform screen tension optimises screen life and stability.
The TETKOmat offers the following advantages:
- Substantial improvement in tension measurement over the time honoured methods such as touch control, gauging by percentage of fabric elongation, and psi pressure values of deflection
- Accurate measurements to check used/reclaimed screens to eliminate worn-out units from production.
- Tension measurements are independent of screen size.
- Warp and weft directions can be checked separately.
- Reproduce and uniform tension, screen after screen.
- An affordable production tool for all sizes of operations.
- Small compact gauge ideal for high volume screen users where more than one TETKOmat is required.
- Improves print registration and reduces rejects resulting in increased productivity.