Why is the correct tensioning of end-tensioned screen meshes so important?
Ensuring your machine has the correct end tension will result in a longer mesh and machine life. Incorrect tension can cause premature mesh failure and potential cracking of the screen.
End-tensioned meshes are typically found on the bottom decks of screen boxes. With end-tensioned meshes, tension bars (also known as banana bars) are used.
Tension bars are shaped like a banana, and 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, while the bar ends are pitched backwards. The mesh is tensioned using the tensioners on either side of the tension bar. By adjusting the end tensioners, the tension bar is straightened, providing the correct tension to the mesh.
Tensioning tips
- Tension each side equally.
- Tension until the mesh sides “feel” the same as the centre. Use a rubber mallet and compare the bounce of the sides versus the centre to determine correct tension.
- New meshes will stretch to some degree during the first few hours of operation, particularly those with small apertures. Re-tension every few hours during the first day or two.
- Check mesh condition and tension at the start of every shift.
- Replace the nose rubber with every third mesh change.
Causes and tips on mesh failures
- Meshes often fail prematurely due to loose tension bars.
- Listen for abnormal, high-pitched noises. This indicates the mesh is loose and moving independently of the screen. Tighten the tension bar immediately.
- Check the condition of the nose rubber. Nose rubber has a limited service life, and if deep grooves caused by the mesh are present, it should be replaced.
Mesh that breaks in multiple areas or along the clamp — often indicated by shiny, worn steel surfaces on the underside of the mesh — is typically the result of a loose tension bar.
