Accumulation Conveyor - Minimum Pressure Accumulation Conveyor
In a distribution or manufacturing operation, accumulation conveyors are commonly used to transport and accumulate cartons or unit loads so that they are efficiently queued up and fed into sorting, wrapping, palletizing, strapping or various others processes. Accumulation conveyors provide a buffer zone where a steady supply of product can be oriented or held back when downstream processes are not ready for additional product. In addition, they can be used to smooth out fluctuations in production line rates caused by stoppages or machines operating at different speeds.
There are two types of accumulation conveyors; minimum and zero pressure. A minimum pressure accumulation conveyor doesn't eliminate the driving force while the products accumulate whereas on zero pressure accumulation conveyors, the driving force is completely eliminated.
Minimum Pressure Accumulation Conveyors
Minimum pressure accumulation conveyor allows products to lightly come into contact with each other as they accumulate on the conveyor line. An effective minimum pressure accumulation conveyor keeps the product stopped, even with the cumulative back pressure of the products behind it, until the appropriate signal is given to release the product. Great consideration and understanding of all the static and dynamic forces must be accomplished, in order to effectively apply minimum pressure accumulating conveyors in your material handling system
Minimum pressure accumulating conveyors are commonly found in manufacturing facilities where there is more uniformity in the product dimensions and weights. Here are two of the most common minimum pressure accumulation case conveyors:
Belt Driven Live Rollers with Pressure Rollers - The operation of a minimum pressure accumulating conveyor using BDLR with pressure rollers is very basic and often a good economic decision. The conveyor uses standard BDLR except that each of the 3 or 4 zones in a 10' or 12' section contains a pressure roller mounted in a spring adjusted carrier. The pressure roller senses the required driving friction required to between the drive belt and the carrying rollers in order to conveyor and accumulate without too much back pressure.
Line Shaft Conveyor - Line shaft, or spool conveyor can be altered just like BDLR in order to make it minimum pressure accumulation conveyor. Each zone in a 10' or 12' section has a pneumatically operated break to be applied to the drive rollers in each zone. When a photoeye senses product presence in the adjacent downstream zone, the break is activated and accumulation occurs. When the zone is cleared, the break releases causing the product to convey to the next zone.