Maximizing Efficiency with Multiple-Layer Designs
The latest advancements in edge-sealing systems involve designs that apply seals externally on the skirtboard steel. The most effective among these designs combine the efficiency of multiple-layer sealing with the simplicity found in single-strip systems.
In the world of conveyor maintenance, workers preparing for cold weather understand the value of layering. Just as they opt for multiple layers of clothing—like an undershirt, shirt, sweatshirt, and jacket—over a single thick layer, the same principle applies to transfer-point sealing. Using several thin layers is preferable to relying on one thick, general-purpose seal. The initial layer in this system is provided by the wear liner inside the chute, which extends near the belt edge to keep larger material particles well clear of the belt. Following this, the sealing system adds the next layer of protection.
Multiple-layer seal designs feature robust elastomers molded into a single-strip with an integrated flap that acts as a secondary seal. This secondary strip, or outrigger, often includes channels that gently guide fines along the belt, redirecting them into the main material flow. 
The primary seal of the system is clamped externally against the chute, extending vertically and lightly touching the belt. Applying light pressure to the belt, the clamp exerts horizontal force towards the chute rather than downward, effectively containing material without subjecting the belt to excessive wear or increased power consumption. This primary seal captures most of the material that manages to escape past the wear liner.
As an outrigger, the secondary seal relies on its elasticity for sealing pressure, ensuring long-lasting performance without frequent adjustments.
Belt sealing and support components work together to ensure an effective seal to prevent the escape of fugitive material.
Installation of the preferred one-piece design is straightforward: the seal is unrolled to the required length, cut, and secured to the skirtboard using a clamping system. This design eliminates unnecessary joints and the complexity of handling multiple pieces. Sealing systems are available in various thicknesses to accommodate different operational demands, and materials tailored for specific requirements such as food-grade, high-temperature, or underground applications.
Advantages of outward sealing are:
- Long lasting, because they are positioned away from material flow and sheltered by the skirtboard and wear liner
- Can be self-adjusting
- Adapt to existing clamp systems
Disadvantages of Outward Sealing are:
- Require greater belt-edge distance (or free-belt distance)
- Vulnerable to damage if belt mistracks from underneath the seal