Understanding the Basic Principles of Rubber Backed Pulley Lagging
The Advantages of Rubber Backed Ceramic Lagging
- The Coefficient of Friction remains at 1 regardless of environmental conditions.
- Conveyor Belt wear is minimized when compared to Direct Bond Ceramics.
- It has a longer service life than plain (non-ceramic) Rubber Laggings.
The Science Behind Rubber Backed Ceramic Lagging
As a section of a Conveyor Belt moves around a Drive Pulley it contracts. This is due to the fact that Conveyor Belts are inherently elastic and the drop in tension from T1 to T2 causes this contraction. Most important to note is that this contraction takes place whilst the section of the conveyor belt is still in contact with the Drive Pulley.
If the lagging surface is rigid or the pulley is bare, this contraction causes a type of continuous belt slip called Localized Belt Slip. Localized Belt Slip is the cause of wear on the underside of a conveyor belt and is also why bare pulleys end up appearing polished with the steel being worn away. The excessive wear caused is the primary reason why Epoxy-Ceramic Laggings should not be used.
This is where Rubber Backed Ceramic Laggings differentiate from Epoxy-Ceramic Laggings. The rubber backing allows the ceramic tiles to move with the contraction of the conveyor belt, thus minimizing Localized Belt Slip. The thicker the rubber backing, the less Localized Belt Slip occurs, to the point where it can be eliminated entirely.
In addition, well designed Rubber Backed Ceramic Laggings provide a coefficient of friction of 1 in any environment. This is for four reasons:
- Ceramic to rubber already offers a high Coefficient of Friction (1 or more).
- The small studs of the tiles mechanically grip on the underside of the conveyor belt.
- The tread pattern sheds foreign matter away from the ceramic tile and conveyor belt interface.
- The minimized Localized Belt Slip increases the circumferential area subject to the static coefficient of friction of ceramic to rubber.