The materials handling systems can be classified according to the type of handling equipment used, type of material handled and the methods, need or functions performed.
Classifications of Material Handling systems in Warehousing
1. Equipment oriented systems depending upon the type of equipment used can be classified as under.
- Overhead Systems
- Conveyor Systems
- Tractor Transfer Systems
- Fork-lift Truck and Pallet Truck Systems
- Industrial Truck Systems
- Underground Systems
- Material oriented systems consisting of the following types
- Unit handling Systems
- Bulk Handling Systems
- Liquid handling Systems
- Method oriented systems can be of the following types
- Manual Systems
- Mechanized or automated Systems
- Job-Shop Handling Systems
- Mass Production Handling Systems
- Function oriented Systems
- Transportation systems
- Conveying Systems
- Transferring Systems
- Elevating Systems
The materials handling equipments are classified into four basic types, viz. conveyors, cranes and hoists, trucks and auxiliary equipment.
Conveyers
These are gravity or powered devices, commonly used for moving loads from point to point over fixed paths.
Types of conveyors
- Belt Conveyor: Motor driven belt, usually made of rubberized fabric or metal fabric on a rigid frame.
- Chain Conveyor: Motor driven chain that drags materials along a metal slide base.
- Roller conveyor: Boxes, large parts or unit lands roll on top of a series of rollers mounted on a rigid frame.
- Pneumatic Conveyor: high volume of air flows through a tube, carrying materials along with the airflow.
- The other types of conveyors are bucket conveyor, screw conveyor, pipeline conveyor, vibratory conveyor, trolley conveyor, and chute or gravity conveyors.
- Advantages of conveyors are that they do not require operators, will move a large volume of products and inexpensive to operate.
Cranes, Elevators and Hoists
These are overloaded devices used for moving various loads intermittently between points within an area, fixed by supporting and binding rails.
- Cranes are devices mounted on overhead rails or ground level wheels or rails. They lift, swing and transport large and heavy materials. Examples are Gantry Crane, Jib Crane and Electrically Operated Overhead Crane (EOTC).
- Elevators are a type of cranes that lift materials usually between floors of buildings.
- Hoists are devices, which move materials vertically and horizontally in a limited area. Examples are Air Hoists, electric hoists and chain hoists.
Industrial Trucks
These devices are used for moving mixed or uniform loads intermittently over variable paths. They are electric, diesel, gasoline or liquefied petroleum, gas powered vehicles equipped with beds, forks, arms or other holding devices. Examples are forklift trucks, pallet trucks, tractor with trailers, hand trucks and power trolleys.
Auxiliary Equipment
These are devices or attachments used with handling equipment to make their use more effective and versatile. Examples are ramps, positioners, pallets, containers and turn-tables.
Miscellaneous Handling Equipments
- Pipe Lines, which are closed tubes that transport liquids by means of pumps or gravity.
- Automatic transfer devices, which automatically grasp materials, hold them firmly while operations are being performed and move them to other locations.
- Automated guided vehicle (AGV) Systems: These devices do not require operations and provide a great deal of flexibility in the paths they travel and the functions they perform and the AGVs are controlled by signals sent through the wires embedded in the floor or inductive tape on the floor surface. A remote control computer is needed to control the movement of AGVs.
- Industrial Robots: a robot is a mechanism that has a movable arm like projection with a gripper on the end that can perform a variety of functions with the control that can be reprogrammed and hence they are very versatile.
- The process design and the principles of efficient materials handling provide the framework for selecting specific materials handling devices as the core of the materials handling system. Each of the handling devices has its own unique characteristics and advantages and disadvantages.
