In large-scale aggregate processing and industrial mineral screening, maintaining consistent hourly tonnage relies on maximizing effective open area. When woven wire screen sections operate at peak performance, fine particles drop rapidly through the mesh near the feed box, allowing distinct size fractions to separate cleanly across the panel surface. However, when feed conditions introduce high surface moisture or high proportions of near-size stone, two distinct operational bottlenecks emerge: blinding and pegging.
Both conditions progressively choke off the passing area of woven wire screen media, forcing usable fines to travel past their intended cut point. As active open area collapses, material accumulates into an overly thick bed depth, causing fine aggregate to ride directly over the panel into the coarse overs pile. Left unaddressed, this loss of separation efficiency starves downstream circuits, increases recirculating loads in secondary crushers, and forces operators to halt production for manual cleaning.
At HAVER & BOECKER, our over 135 years of wire weaving expertise have demonstrated that solving blinding and pegging requires matching the physical geometry of the screen section to the specific characteristics of the feed stream. By engineering high-tensile wire mesh with specialized slot configurations, precise crimp styles, and optimized wire diameters, we help producers keep their screen media clear and maximize plant profitability.
In this article, we will detail the physical differences between blinding and pegging, examine the raw material factor that causes active open area loss, and explore how slotted weaves restore material flow in problem screening circuits.
Although blinding and pegging both result in blocked open area and lost screening capacity, they are driven by entirely different mechanical failure modes. Understanding which condition is occurring on your vibrating screen section is critical to selecting the proper corrective action.
Screen Blinding is primarily a moisture-driven adhesion process. It occurs when damp, fine particles such as clay, silt, or stone dust adhere to the individual wires of a screen section.
As more material passes over the panel, these damp fines build up along the wire intersections, gradually bridging across the aperture until the opening is completely covered. Blinding typically forms a continuous crust over large portions of the screen surface, bringing stratification to a complete halt.
Screen Pegging, by contrast, is a physical wedging mechanism caused by particle geometry. It happens when hard, near-size stones (particles slightly larger than the nominal aperture size) enter the openings under high G-force acceleration.
Rather than passing through or bouncing off, these particles become mechanically wedged between adjacent wires. Unlike blinding, which involves fine mud or dust, pegging fills individual apertures with solid rock, creating a jagged, studded panel surface that resists normal material travel.
Eliminating screening bottlenecks requires identifying the specific raw feed characteristics that trigger open area blockage. While equipment stroke and vibration frequency play supporting roles, the physical properties of the aggregate stream dictate how material interacts with the wire mesh, which include:
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Recognizing these feed characteristics allows producers to proactively alter wire mesh specifications before material buildup forces an unscheduled washdown shift.
Standard square mesh panels feature equal spacing between warp and shute wires, creating numerous wire cross-points where damp fines take root or square particles lodge.
Replacing square openings with engineered slotted weaves alters the surface geometry of the screen section, providing a solution that resists both blinding and pegging.
HAVER & BOECKER manufacturers specialized slotted woven wire configurations engineered to keep active open area clear in severe screening applications:
Switching from rigid square mesh to Ty-Rod or TON-CAP slotted wire mesh restores lost passing capacity without requiring structural modifications to your screening equipment or mounting hardware.
Screen blinding and pegging are not mandatory costs of processing damp or difficult aggregate feeds. By distinguishing between moisture-driven blinding and mechanical pegging, plant operators can select media solutions that eliminate open area loss, maintain sharp cut points, and protect downstream processing efficiency.
Optimizing screen section performance requires matching wire diameter, allow selection, and aperture geometry to the exact demands of your feed material. Deploying specialized slotted wire media such as Ty-Rod or TON-CAP provides the self-cleaning action needed to keep production lines moving at maximum hourly tonnage.
At HAVER & BOECKER, we engineer high-tensile woven wire screen sections to deliver superior open area, exceptional wear life, and precise separation accuracy. By controlling wire drawing tolerances, weave consistency, and panel tensioning systems, we help aggregate and mineral producers eliminate carryover losses, prevent unplanned downtime, and maximize plant profitability.
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