The essence of a flow rack is to utilize gravity, allowing goods placed on it (typically stored in standard plastic bins or cartons) to automatically slide from the loading end of the rack to the picking end, thereby achieving "First-In, First-Out" (FIFO) inventory management.
Physical Structure and Components
A complete flow rack system typically consists of the following parts:
Frame / Track Skeleton: Usually a metal structure that supports the entire system and is set at a precise inclination angle (typically between 3° and 5°).
Flow Rails (Core Component):
These are rows of parallel-installed rollers or wheels.
Roller Type: Consists of many small rollers densely arranged. They offer strong load-bearing capacity, smooth operation, and are suitable for heavier goods.
Wheel Type: Consists of cylindrical wheels. They have lower rolling resistance, produce less noise, and are suitable for lighter cartons.
Divider Rails: Installed on both sides of the flow rails to separate different product lanes and prevent containers from veering off course.
Braking Devices:
End Stops: Located at the picking end to prevent containers from sliding out.
Dampers / Speed Regulators: Installed at specific points on the track (especially near the end) to control the sliding speed, prevent containers from accelerating and impacting due to gravity, and ensure a smooth stop.
Loading End and Picking End:
Loading End (Rear/High End): Where staff place full containers.
Picking End (Front/Low End): Where staff take the first container for picking or distribution. Once a container is removed, the ones behind automatically slide forward to fill the position.
Working Principle and Process (Animated Description)
Loading: A worker places a loaded container (e.g., a tote) at the rear end (high end) of the rack.
Sliding: Due to the rack's incline, the container begins to slide slowly and steadily towards the front end on the flow rail rollers, driven by its own gravity.
Queuing: The container slides to the front end and is stopped by the container in front of it or by the end stop, lining up in sequence.
Picking: The worker always removes the first container from the front end (low end) of the rack. Once this container is removed, all subsequent containers automatically slide forward one position.
Cycle: When the container at the rear end is emptied, a new full container is replenished at the rear, and the cycle repeats.
Core Features and Advantages
Enforces First-In, First-Out (FIFO): This is its greatest advantage. Goods slide automatically, ensuring the picking sequence strictly follows the loading order. It is perfect for materials with shelf-life requirements (e.g., electronic components, pharmaceuticals, food).
Improves Picking Efficiency:
Pickers do not need to move around or enter the rack aisles; they operate from a fixed picking station.
No need to search for goods; the next container to be picked is automatically "delivered" to hand.
Significantly reduces walking and searching time.
High Space Utilization: Requires fewer aisles (only needed at the picking end), offering higher storage density than traditional shelving.
Reduces Labor Intensity: Utilizes gravity for automatic transport, eliminating the need for manual container handling.
Visual Inventory Management: Empty and full statuses are clear at a glance, facilitating quick replenishment and inventory counting.
Primary Application Scenarios
Production Line Material Supply (Lean Manufacturing): Provides parts to assembly lines just-in-time. Empty containers returned signal the need for replenishment.
Sorting Areas in Logistics Distribution Centers (Order Picking): Used for "piece picking" or "batch picking," especially suitable for goods with many SKUs and fast turnover.
Cold Chain Storage: Reduces staff movement and door opening time in cold storage, improving efficiency and saving energy.
Supermarket Backroom Warehouses: Used for quickly restocking front-store shelves.
Manufacturing Industries such as electronics and automotive parts: Manages a large number of standard components.
