What Skirting Does
At conveyor loading zones, material drops onto the moving belt and tends to scatter sideways. Skirt boards are the side walls that contain material at the loading point, preventing it from spilling off the belt edges. The seal between the skirt board and the belt surface is the skirting β the component that closes the gap and prevents fine material and dust from escaping underneath.
The skirting is a wear component that contacts the moving belt. Choosing the right material and design affects both seal effectiveness and belt cover wear.
The Risk: Skirting That Damages the Belt
The skirt seal contacts the belt surface as it moves. If the skirting is too hard, too sharp, or under too much clamping pressure, it abrades the belt cover β sometimes faster than the material being conveyed. A skirting system that seals well but wears the belt is trading one problem for another.
The goal is a seal that contains material without significantly accelerating belt cover wear.
Rubber Skirting
Rubber skirting strips are the standard solution used on most conveyors worldwide. A rubber strip (typically 60β80 Shore A natural rubber or SBR) is clamped in a steel holder and adjusted to contact the belt surface with light pressure.
How it works: The rubber strip conforms to the belt surface, compensating for minor belt sag variations and idler misalignment. As the rubber wears, it can be adjusted downward. When fully worn, the strip is replaced.
Advantages: - Flexible β conforms to belt surface, compensating for irregularities - Can be adjusted as it wears - Replaceable without modifying the skirt board structure - Lower belt cover wear than steel contact (rubber on rubber is gentler than steel on rubber) - Low cost per strip - Widely available
Limitations: - Wears faster than steel in highly abrasive environments - Can harden and lose flexibility in cold climates - Replacement frequency higher than some alternatives
Steel Skirting (Steel Wear Plates)
Some operations use steel wear plates as the primary skirt seal, either as the direct belt-contact component or as backing for a thin rubber seal layer.
When steel skirting is used: - As backing structure with rubber seal mounted on the face - In very high-temperature environments where rubber degrades - At the rear of the skirt box as a secondary seal after initial rubber contact
Direct steel-to-belt contact is generally avoided because steel sliding on belt cover causes rapid cover abrasion. Wherever possible, the belt-contact face of the skirt system is rubber, not steel.
Modern Skirting System Design
Good current practice uses a layered skirting approach:
Primary seal: A soft rubber strip (40β50 Shore A) that contacts the belt surface with minimal pressure. This seals fine dust and particles. Wears relatively fast but is inexpensive to replace.
Secondary seal (optional): A stiffer rubber or UHMWPE strip behind the primary, set slightly higher off the belt. This catches any material that passes the primary seal.
Skirt board panels: The structural steel walls above the skirting. These contain the material volume and do not contact the belt directly.
Adjustment system: The clamping and adjustment hardware that holds the skirting strips and allows downward adjustment as they wear.
Skirting Pressure β The Critical Variable
The most common cause of skirting-related belt damage is excessive clamping pressure. If the skirting strip is pressed hard against the belt under high spring or clamp tension:
- Belt cover abrasion rate increases significantly
- Heat can build up at the contact point
- Edge-tracking problems can develop as the seal drags
Correct approach: Set skirting to the minimum pressure that achieves acceptable sealing. A small amount of dust leakage at the skirt seal is far less costly than accelerated belt cover wear.
UHMWPE Skirting
Ultra-high molecular weight polyethylene (UHMWPE) is used in some premium skirting applications as the belt-contact strip.
Advantages over rubber: - Lower coefficient of friction against belt cover than rubber - Very high abrasion resistance β long wear life - Does not harden in cold temperatures the way some rubbers do
Disadvantages: - More rigid β less conforming to belt surface variations - Higher cost than standard rubber skirting - Can cause belt cover scratching if edges are not properly chamfered
Frequently Asked Questions
Our skirting wears out every 3 weeks. Is there a better material? First check skirting pressure β it may be set too high. If pressure is correct, try a stiffer rubber compound (65β70 Shore A instead of standard 60 Shore A) for longer life, or consider UHMWPE for the highest wear resistance.
Our belt shows wear marks under the skirt board. What's causing it? Skirting pressure too high, skirting strip edge sharp or damaged (should be chamfered), or a piece of trapped material lodged between skirt and belt. Inspect the skirting system and reduce pressure to minimum effective level.
How long should rubber skirting strips last? In light duty applications, 3β6 months. In abrasive heavy-duty applications with high material velocity, 4β8 weeks. UHMWPE typically lasts 3β5Γ longer than rubber in the same position.
Can you supply skirting strips cut to length? Yes. We supply rubber skirting strip in standard thicknesses and hardnesses, cut to your specified length. Contact us with your skirt board length, strip thickness required, and rubber hardness preference.
Contact Elephant Rubber
We supply rubber skirting strips in a range of hardnesses and dimensions. Contact us with your loading zone dimensions and material type.