Vibrating Screen Mesh Blinding and Pegging: Causes, Solutions, and Mesh Selection Tips
How to Stop Vibrating Screen Mesh Blinding and Pegging From Slowing Down Your Plant
When material gets stuck on a vibrating screen, the production process slows down quickly. The two most frequent issues encountered in aggregate, mining, chemical, and food processing plants include blinding and pegging. These two problems reduce your screening efficiency and make your separation less accurate, wasting your time and damaging the equipment.
This post explains why such clogs occur, how to differentiate them, and which mesh will be appropriate to ensure trouble-free operations.
What We Will Cover
- What is vibrating screen mesh blinding?
- What is vibrating screen mesh pegging?
- Blinding vs pegging: Key differences
- Main causes for both issues
- Impact on screening performance and how to diagnose it
- Practical solutions for blinding and pegging
- Tips for choosing the right mesh and wire material
- Information to share with your mesh manufacturer
What Is Vibrating Screen Mesh Blinding?
Vibrating screen mesh blinding is a phenomenon where wet fines, water, or sticky materials form a film over the screen mesh. This film prevents the smaller particles from passing through the screen. With time, the film builds up and closes all the holes on the screen, causing vibrating screen mesh blinding.
Blinding occurs most frequently where there are high amounts of clay or where moisture content exceeds 5% to 8%.
What Is Vibrating Screen Mesh Pegging?
Vibrating screen pegging occurs when near-sized particles become wedged in the holes. They are referred to as wedged particles or trapped stones whose sizes are very similar to the size of the apertures.
Rather than passing through or bouncing off, these particles drop halfway into the mesh hole and jam tightly there, forming a tough screen mesh clogging problem that prevents other material from passing through.
Blinding vs Pegging: What Is the Difference?
Though both lead to blocking the screen mesh, they occur differently:
Common Causes of Vibrating Screen Mesh Blinding
- High Moisture: Extra water makes dust moist and adhere to the wire like mud.
- Incorrect vibration: The wrong vibration frequency does not help remove adhering particles from the wire surface.
- Wrong Open Area: Small wires have more open area while big wires tend to trap sticky dust.
- Static Charge: Fine dry powders can build static electricity and attach to the metallic surface.
Common Causes of Vibrating Screen Mesh Pegging
- Near-Size Material Overload: Excessive number of rocks corresponding to the size of the mesh hole.
- Incorrect Mesh Design: Using the square design when stones have an elongated or needle-like shape.
- Flaky Particle Shape: Stones with flat shapes can get stuck into the mesh holes.
- Low Stroke Amplitude: Not enough stroke height enables stones to wedge into the mesh holes.
How Blinding and Pegging Affect Screening Performance
Plant data indicates that untreated vibrating screen mesh clogging can lower overall plant capacity by 20-40%.
- Lower Capacity: Blocked holes cause material of adequate quality to bypass into the tailings pile.
- Higher Load on Deck: The excess weight causes wear and tear, reducing the bearing life of the drive system by 15%.
- Increased Wire Wear: The increased buildup results in additional friction.
How to Diagnose Whether the Screen Is Blinded or Pegged
- Visual Surface Check: If your screen seems to be entirely coated with a layer of mud or cake, you have a vibrating screen blinding.
- Underside Inspection: When you observe numerous individual rocks trapped under the deck of the vibrating screen, you are experiencing vibrating screen pegging.
- Sound and Vibration: Additional weight due to excess buildup affects the sound of the deck and lessens stroke movement.
Solutions for Vibrating Screen Mesh Blinding
- Adjust Deck Motion: Increasing vibration frequency provides acceleration for sticky fines.
- Add Ball Trays or Anti-Blinding Chains: Balls falling on the under-deck cause sticky fines to fall off the wire.
- Use Heated Decks: Heated decks dry the moisture immediately, preventing any sticking.
- Apply Spray Water: High-pressure water sprays make the sticky feed a slurry.
Solutions for Vibrating Screen Mesh Pegging
- Optimize Screen Tension: This prevents the mesh from sagging, allowing it to vibrate freely and shoot out wedged material.
- Change Aperture Geometry: From square shape to rectangular or self-cleaning ones.
- Increase Stroke Length: This will give the entangled rock sufficient inertia to be released.
How to Select a Mesh That Reduces Blinding and Pegging
Choosing the right vibrating screen mesh depends on your material, moisture content, and particle shape.
Wire Material Selection
- Spring Steel & High Carbon Steel: Good resistance to abrasion due to sharp rocks.
- Stainless Steel (SS304 & SS316): Best in wet or corrosive conditions; smooth surface prevents sticky buildup.
Wire Diameter
Small diameter wire allows for greater open area, so sticky material will have less metal to attach to. Thicker wire, on the other hand, is more durable under abrasion stress.
Square, Rectangular or Self-Cleaning Mesh: Which Should You Use?
- Square woven wire mesh: Ideal for precision separation, but susceptible to pegging because of feed material close to size.
- Rectangular slots: Eliminates pegging to a large extent since rocks seldom fit into both dimensions simultaneously.
- Self-cleaning mesh: Comprises crimped wires that vibrate individually. Very efficient in applications involving moisture.
When Should the Screen Mesh Be Replaced?
Change your mesh right away if you find:
- Wires that are broken and/or frayed, causing oversized contamination.
- Much wire thinning resulting in reduced tension of the screen.
- More than 30% of plugged screen mesh that can no longer be cleaned manually.
Information to Share with a Screen Mesh Manufacturer
When ordering custom screens, provide:
- Precise measurements of deck size and type of hook.
- Material specifications such as moisture content, bulk density, and particle size.
- The metal preference (SS304, SS316, or high-carbon steel).
- Aperture size and wire diameter.
Final Takeaway: Preventing Blinding Starts with the Right Mesh
Preventing vibrating screen mesh blockage involves properly aligning the mesh design with the characteristics of the feed material. For efficient screening over long periods, use quality industrial wire mesh.
As one of the leaders in manufacturing of Industry Specific Wire Mesh and Metal Products, Banaraswala offers a complete selection of screen decks. Whether you require woven wire mesh, welded wire mesh, perforated sheets, expanded metal, or chain link fencing, Banaraswala can provide you with quality solutions according to your requirements in plants.
