ZPA Roller Conveyors

Saturn ZPA Roller Conveyors (Zero Pressure Accumulation) are designed to automatically transport and accumulate cases, cartons, trays, totes and other products without allowing accumulated products to contact or push against one another.

The conveyor is divided into a series of independently controlled accumulation zones. Each zone typically accommodates one product and incorporates a photoeye or sensor to detect when the zone is occupied. The control system communicates between adjacent zones to determine when products can advance.

When the downstream zone is available, the product automatically advances. When the next zone is occupied, the upstream product is stopped and held in its own zone, maintaining separation between products. This creates true zero-pressure accumulation and prevents the backpressure normally generated when products accumulate against one another.

Each zone uses a 24V DC motorized drive roller (MDR). The motor is contained within the designated drive roller, which then powers several adjacent non-motorized slave rollers through Poly-V belts, O-belts or another roller-to-roller transmission system. The individual slave rollers do not contain motors.

This decentralized drive arrangement allows individual conveyor zones to operate only when product movement is required. When a zone does not need to transport a product, it can remain stopped, reducing unnecessary conveyor operation, noise and energy consumption.

ZPA conveyors are particularly useful for creating controlled product buffers between machines operating at different speeds. Products can accumulate temporarily without stopping the entire upstream production line and are automatically released as downstream capacity becomes available.

The system can operate in singulation mode, maintaining a gap between each product, or products can be released in groups or continuously when the downstream equipment is ready to receive them. Modern MDR controllers support ZPA and different release/control logic depending on the application.

ZPA Roller Conveyors can incorporate straight sections, powered curves, merges, diverts, product stops and 90° transfers, allowing complete automated case-handling systems to be built around the same zoned conveyor technology.

Conveyor width, roller spacing and zone length are customized according to the product dimensions, weight and required accumulation capacity. Zone lengths are generally selected so that each accumulated product can be independently detected and controlled.

Saturn ZPA Roller Conveyors are ideal for integration with case erectors, case packers, case sealers, print-and-apply systems, inspection equipment, palletizers and other end-of-line machinery where controlled product accumulation and release are required.