Why is the correct tensioning of end tensioned screen meshes so important?
Ensuring your machine has the correct end tension will ensure a long mesh and machine life. Incorrect tension will cause premature mesh failure and possible screen cracks.
End tensioned meshes are usually found on the screen box bottom decks. With end tension meshes, tension bars (or banana bars) are used.
Tension bars are shaped like a banana. The curve of the bar must fit into the clamping plate of the mesh. The apex of the curve must face towards the centre of the clamping plate. The bar ends are pitched backwards. The mesh is tensioned using the tensioners either side of the tension bar. By adjusting the end tensioners, the tension bar is straightened to provide the correct tension to the mesh.
- Tension each side equally.
- Tension until the mesh sides tension “feel” the same side as the centre. Use a rubber mallet and bounce the sides vs. centre to determine the tension.
- Any new mesh will stretch to some degree in the first few hours of operation, particular small apertures. Re-tension every few hours over the first day or two.
- Mesh condition and tension should be checked at the start of every shift.
- Replace nose rubber with every third mesh change.
CAUSES / TIPS ON MESH FAILURES
- Meshes fail prematurely due to loose tension bars.
- Listen for abnormal noises (high pitched sounds). This is a sign that the mesh is loose and moving independently to the screen. Tighten the tension bar.
- Check nose rubber condition. Nose rubber has a shelf life, if you find large grooves caused by the mesh, replace them.
Mesh broken in multiple areas or along the clamp (shiny worn steel surfaces will be found on the underside of the mesh) loose tension bar.