Zero line pressure (ZLP) conveyors are predominantly used for transporting more fragile products and provide smooth operation and product accumulation without the product touching. This is achieved by creating product “zones” along the length of the conveyor system.
Each zone has its own motorized roller assembly which parasitically drives a series of slave rollers via elastomeric urethane belts. The stop / start process of each driven roller is controlled by a photoelectric cell positioned within the zone, which sends either a “zone occupied” or “zone vacant” signal to the onboard control system.
As a zone becomes “vacant” the previous zone (or zones if occupied) power up feeding the product/s along the conveyor in a cascading / indexing manner ensuring that product is allowed to feed forward to the next available zone. This singulation feature allows product/s to be removed from the conveyor at any location on the conveyor but will still then allow full accumulation. Also, since the motors in the rollers only run when required this can provide a considerable annual saving on energy costs. Positive dynamic braking in each zone ensures accurate stopping and reduces the possibility of damage to fragile items during accumulation.