A flat belt is a belt with a flat surface, usually evenly textured on both sides, used in a pulley system. Historically, flat belts were often used for transmission of power from flywheels to other parts of machinery, and today, they are commonly seen in use as conveyor belts or parts of belt arrays, where the flat surface makes it easy to move products along the top of the belt. Numerous companies design machines intended to work with such belts, and sell replacement belts and belt sections made from a variety of materials.
Leather was one of the original materials used in belt construction. Today, nylon and other tough synthetics are commonly used because they hold up longer. Rubber, metal, and other materials may be involved in the construction of a flat belt, and some are reinforced with especially strong materials to address concerns about structural integrity. When a flat belt is used as part of a transmission, sometimes the belt is twisted to create a Mobius Strip so it will wear evenly through use, lengthening the time between replacements.
In conveyer belt construction, the flat belt can be used as a single broad belt on an assembly line or as part of an array of webbed belts. As the belts are turned by pulleys, whatever is resting on the belts is pulled along, moving it to a new location. The belts can be used to support various components during manufacture and assembly, as seen on web printing presses where the belts hold the paper while it dries, and to move products along the line.
Such belts are usually easy to replace, although the line does need to be shut down while the old belt is removed and the new one is installed. Halts are also usually recommended for belt inspections to reduce the risk of injuries to the inspector and to allow people to review the entire belt in detail without worrying about missing sections. Standardized sizes are common, allowing people to use interchangeable products in repair and replacement.
Each flat belt carries a rating providing information about recommended uses. Generally, belts cannot be used with weights heavier than those they are rated for, as they may fail. On a high speed assembly line, a failure could damage the equipment or cause serious injuries for workers on the line. Belts also need to be inspected for cracking, fraying, and other signs of stress so they can be replaced in a timely fashion.