What Are Breaker Fabrics and How Do They Influence Conveyor Belt Performance?
A conveyor belt is far more complex than just a sheet of rubber. It’s a multi-layered system made from different materials, each designed to deliver optimal performance in terms of durability, flexibility, and elongation.
On mine sites, especially in short-cycle systems, conveyor belts face extreme conditions: harsh impacts, sharp and abrasive materials, heavy loads, and prolonged environmental stress. Protecting the belt’s core structure is critical, and that’s where breaker fabrics come in.
What Are Breaker Fabrics?
Breaker fabrics act as secondary reinforcements, positioned between the carry cover and the steel cords (the carcass), typically 1–4 mm above the cords. If the steel cords are the “heart” of the belt, breaker fabrics are the “ribcage”, absorbing force, preventing rips, and shielding the internals.
Damage to steel cords often means replacing entire belt sections, but breaker fabrics help prevent this by dispersing impact and resisting tears. They’re also called rip fabrics because they play a major role in stopping longitudinal (lengthwise) rips. This extra layer, usually nylon fabric, makes it harder for tears to spread.
Nylon’s ability to stretch and compact is key. If a rock gets lodged between pulleys or under the belt, breaker fabrics bunch together and force the belt to stop, rather than letting the rock tear through as the belt keeps moving.
Types of Breaker Fabrics
In steel cord belts, we typically recommend two types:
- Heavy Breakers – Installed on the carry/top cover side, designed to withstand heavy impacts.
- Light Breakers – Installed on the pulley/bottom cover side, for lighter protection.
The main difference lies in their weight resistance (grams per square meter), as the top cover takes the brunt of the punishment.
Both types usually use a Leno weave; a textile structure where pairs of warp yarns twist around weft yarns, creating a stable, open mesh. This weave is strong, breathable, and dimensionally stable, preventing slippage during fabrication and splicing. It’s used in everything from fishing nets to conveyor belts.
For belts handling sharp, coarse materials, steel filament weaves with nylon fabric weft (known as steel mesh banner) are also available.
Looking for Ultimate Durability? Meet DynaFlex
DynaFlex is the ultimate form of breaker fabrics, developed by our sister company, Fenner Dunlop Americas.
The key characteristic that sets it apart is that it has straight warp polyester yarns and heavy-duty nylon yarns going in both directions in a matric, held together by nylon threads. This design very effectively dissipates force and provides superior impact resistance compared to typical Leno weave nylon breaker fabrics.
We recommend DynaFlex for primary crushers, any system with a short loop cycle where repeated impacts need to be endured, reclaimers, stackers, and other similar systems.
UsFlex belts replace traditional steel cords with Dynaflex fabric as the carcass. The result?
- Greater elongation
- Superior durability
- Exceptional rip resistance
- Guaranteed permanent elongation of less than 1%
We recommend UsFlex for most new conveyor systems. However, because of its higher elongation, it requires heavier gravity take-up weights, making it unsuitable for older systems designed for steel cords without system overhaul.
As the industry evolves, we expect UsFlex to become the go-to choice for high-durability applications worldwide.
