Why do my screens crack at the welds or deform under load?

The symptom

Cracks form at welds or clamped edges of screen decks, baskets and support screens. Apertures in the loaded area can move out of tolerance and affect product quality. The same damage may return after repair.

Root causes

1. 01 Woven mesh can shift under point loads. Apertures open and wires may work-harden where they repeatedly flex.
2. 02 A weld or clamped edge without sufficient load spreading concentrates vibration loads on a small area of material.
3. 03 Holes close to an edge or weld leave too little solid material to carry the load.
4. 04 Resonance can occur when a deck or basket is loaded near its natural frequency. This increases the alternating load.

Suitable filter media

• ▸ Use welded mesh as a structural layer where required. Welded crossings limit aperture movement. A fine retention layer can sit above it as a separate medium.
• ▸ A composite screen combines fine woven cloth for retention with a welded backing for support.
• ▸ Size unperforated borders and load-spreading edge profiles for the actual mounting and loads.
• ▸ Match plate thickness, hole pattern and open area to the load case. Check the selected geometry with the relevant calculations.

Prevention

• ⊕ Include static loads, vibration and point loads in every screen enquiry alongside the retention requirement.
• ⊕ Inspect weld zones and edges at fixed intervals, paying attention to previous crack initiation points.
• ⊕ When repairs recur, assess whether the design needs to be adapted to the load.