When wet, damp or clayey material is screened, the openings of conventional woven screen wire fill up quickly; screen capacity drops, fines that should report to the undersize carry over to the oversize, and the operator has to stop frequently to clean the wire. Non-clogging screen wire (self-cleaning screen wire, harp screen) is a screen surface developed to solve this problem. In this guide we cover how non-clogging wire works, its types, when it should be preferred over woven wire or polyurethane panels, and key installation and maintenance points.
What Is Non-Clogging Screen Wire and How Does It Work?
In conventional woven wire, longitudinal and cross wires lock into each other; the openings are fixed and rigid. In non-clogging screen wire, the wires mostly run in one direction only and are held together at intervals by polyurethane or rubber strips. The wire sections between the strips are free; as the screen vibrates, each wire also vibrates on its own. This secondary vibration continuously releases particles stuck in the openings and damp fines adhering to the wires.
There are two different forms of screen clogging, and non-clogging wire acts on both:
- Pegging: Particles very close to the opening size wedge into the apertures and stay there. Common with hard, angular material.
- Blinding: Damp fines and clay form a crust on the wires and close the openings. Seen with wet and clayey material.
Types of Non-Clogging Screen Wire
| Opening Type | Construction | Typical Use |
|---|---|---|
| Slot (straight, S type) | Parallel wires, long rectangular openings; the highest open area | Sand, fine aggregate, dewatering and products where particle shape is not critical |
| Triangle (T type) | Wires zigzag to form triangular openings | Between slot and diamond; general-purpose fine screening |
| Diamond (D type) | Wires form diamond-shaped openings; size control closest to woven wire | Applications such as chippings and aggregate where flaky and elongated particles must report to the oversize |
| Wave (crimped) wire | Crimped wires laid side by side form slot openings, sometimes without strips | An alternative to woven wire for damp material at medium openings |
The wire is mostly high-carbon spring steel; stainless steel wire may be preferred in highly corrosive or washing applications. For wire diameter and opening selection, see our screen wire sizes and mesh chart guide.
When Should Non-Clogging Screen Wire Be Used?
- When the material is damp, wet or clayey and woven wire clogs frequently,
- When capacity is insufficient on fine fractions (e.g. 0–3 or 0–5 mm sand and dust removal),
- When fine separation is done on lower decks and open area needs to be increased,
- When the wire is frequently stopped and cleaned because of pegging.
On the other hand, on top decks where coarse and highly abrasive material lands directly, thick woven wire, polyurethane or rubber panels usually last longer. For a comparison of screen media types, see our screen media selection guide.
Non-Clogging Wire vs Woven Wire
| Criterion | Woven Screen Wire | Non-Clogging Screen Wire |
|---|---|---|
| Resistance to clogging | Low with damp and clayey material | High; wires clean themselves |
| Open area | Depends on wire diameter, lower | Generally higher |
| Particle shape control | Good (square opening) | Flaky and elongated particles can pass slot types; better with diamond types |
| Impact and wear resistance | High with thick wire | Lower with thin wires; must be protected at the feed point |
| Price | Lower | Higher; to be weighed against higher capacity and less downtime |
Selection Checklist
- Product specification: If the product has a flakiness or elongation limit, choose diamond or triangle openings instead of slots; confirm the result with sieve analysis.
- Opening and wire diameter: Wire diameter is chosen according to feed size and impact load; too thin a wire breaks quickly, too thick a wire reduces the self-cleaning effect.
- Panel size and tensioning type: Panel width and length, hook type and hook angle must match your screen’s tensioning system exactly.
- Deck position: Use non-clogging wire mainly on lower decks where fine separation is made; on top decks always provide impact protection.
- Material and corrosion: In washing circuits or with acidic water, consider stainless wire.
Installation and Maintenance
- Tension the wire to the value in the manufacturer’s instructions; slack wire both breaks early and loses its self-cleaning effect.
- Check the rubber profiles on the crown bars; worn profiles cut the wire.
- Prevent material from dropping directly onto the wire at the feed point; use an impact plate or rubber lining.
- Even a single broken wire lets oversize pass into the undersize; inspect the wire visually during shift checks and replace broken wire promptly.
- If the panel can be turned or repositioned to even out wear, follow the manufacturer’s recommendation.
For all screen spare parts see our screen spare parts guide, and for screen types and vibration settings our vibrating screen guide.
Frequently Asked Questions
What is non-clogging screen wire?
A screen surface in which each wire can vibrate independently, so that particles stuck in the openings and damp material adhering to the wires are cleared automatically. It is also known as a harp screen or self-cleaning screen wire.
What materials is non-clogging screen wire used for?
Damp sand, clayey limestone, wet aggregate, coal and all kinds of sticky material with fine fractions.
Can non-clogging wire replace woven wire on an existing screen?
Yes; as long as the panel size, hook type and tensioning system are made to suit your screen, it fits the same position. The condition of the crown bar profiles should also be checked.
How long does non-clogging screen wire last?
Service life varies widely with material abrasiveness, particle size, wire diameter, deck position and tensioning accuracy. Correctly tensioned wire protected from feed impact lasts noticeably longer.
Non-Clogging Screen Wire from CSP Mühendislik
CSP Mühendislik supplies non-clogging screen wire, woven screen wire, polyurethane and rubber screen panels and screen spare parts to suit your screen dimensions and material. Just send your screen model, deck position, panel size and required opening; we will determine the right wire type together.
