1.1.17 Conveyors

1.1.17 Conveyors

A conveyor is a horizontal, inclined or vertical device for moving or transporting bulk materials or objects in a path predetermined by the design of the device and with fixed or selective points of loading and discharging materials or objects.  

Conveyor systems allow quick and efficient transportation for a wide variety of materials, which make them very popular in the material handling and packaging industries. Many kinds of conveying systems are available and are used according to the various needs of different industries.

Industries that use conveyor systems include the automotive, agricultural, computer, electronic, food processing, aerospace, pharmaceutical, chemical, bottling and canning, print finishing and packaging industries. Although a wide variety of materials can be conveyed, some of the most common include food items such as beans and nuts, bottles and cans, automotive components, scrap metal, pills and powders, wood and furniture and grain and animal feed. Many factors are important in the accurate selection of a conveyor system. It is important to know how the conveyor system will be used beforehand. Some individual areas that are helpful to consider are the required conveyor operations, such as transportation, accumulation and sorting, the material sizes, weights and shapes and where the loading and pickup points need to be.

As with any mechanical and electrical device, conveyors can present some safety concerns. Since they have many moving parts, anyone who works on, near, or around them should be well versed in conveyor safety — and also why each rule is important and necessary.

Types of Conveyers

  • Belt Conveyors
  • Screw Conveyors
  • Chain Conveyors
  • Roller Conveyors

Conveyor Injuries

Conveyor‐related injuries often involve a worker’s body parts being caught in nip points or shear points when:

  • Cleaning or maintaining a conveyor, especially when it is still operating.
  • Reaching into an in‐going nip point to remove debris or to free jammed material. 
  • A cleaning cloth or clothing is caught in the conveyor and pulls fingers or hands into the conveyor

Other conveyor‐related hazards include improperly guarded gears, sprocket and chain drives, horizontal and vertical shafting, belts and pulleys, and power transmission couplings.

Safeguarding Conveyors

Overhead conveyors warrant special attention because most of the drive train is exposed. Workers have been injured or killed while working in areas underneath conveyors and in areas around lubrication fittings, tension adjusters, and other equipment with hazardous energy sources.

Let us look at the standards CEMA, the Conveyor Equipment Manufacturers Association, has established for conveyors:

  • Do not climb, sit, stand, walk, ride, or touch the conveyor at any time

Not following this rule can lead to injury, and it happens more often than you would like to believe. It is imperative that workers never climb, sit, stand, walk, ride or even touch the conveyor line at any time. It is common sense, but people tend to get mischievous about it and there are injuries and equipment damage due to not following this rule every year.

  • Do not perform maintenance on conveyor until electrical, air, hydraulic, and gravity energy sources have been locked out or blocked

Do not perform any maintenance (or even open a panel or guard) until electrical, air, or hydraulic power sources are disconnected or blocked out. Block the incline on a gravity conveyor before getting to work on it. There are technicians who sometimes become too confident in their ability to work on machinery even when it’s connected to power because they have been around it a long time and know it well. It’s this kind of thinking that can lead to injuries.

  • Lockout-Tagout Devices

Operate equipment only with all approved covers and guards in place. They built the conveyors with guards for a reason – safety! Operating it without the guards is one of the most unsafe, and sadly, most common occurrences in the industry. Guards are sometimes removed by plant employees for maintenance, or because they obstruct someone’s access doing work. This exposes machinery, gears, chains, and moving parts that are extremely dangerous if left unguarded.

  • Do not load a stopped conveyor or overload a running conveyor

This simple safety standard helps preserve your conveying equipment because it helps prevent overheating. Workers should not ever load a conveyor when it is stopped, or overload it when it is running.

  • Ensure that all personnel are clear of equipment before starting

Workers should always be certain that everyone is clear of the conveyor before starting it up. Many times, factories install warning horns to alert workers that the conveyors are about to become active. This is an excellent and relatively inexpensive safety upgrade you can make, but you shouldn’t stop there. Training should also be included about what the warning horn means and how injuries can occur if it’s ignored.

  • Allow only authorized personnel to operate or maintain material handling equipment

Only workers who have been trained should be permitted to operate and perform maintenance on conveyors. This is for two reasons:

  • Safety of the technician. Conveyors can be dangerous to those who do not thoroughly understand the equipment and how to safely work on it.
    • Only trained personnel can really maintain a conveyor to perform at peak efficiency. This is not necessarily a safety concern, although it can be if sub-par conveyor performance causes workers to try to look at it on their own or bypass guards.
  • Do not modify or misuse conveyor controls

Conveyor controls are not just on/off switches. They are any kind of electronic or mechanical devices used during conveyor operation. These controls should never be modified for any reason by unqualified personnel. Monitor your various controls to be sure no one has misused, modified, or disconnected them.

  • Keep clothing, body parts, and hair away from the conveyor

It cannot be stressed enough how important it is to keep clear of conveying equipment while it is in operation. This is one of the most common ways to be injured around a conveyor. Workers should keep their hands off of conveyors. Those with long hair, loose clothes, or ties should be exceptionally careful (or should bind their hair and clothes before going near the machinery). Ties should be thrown over the shoulder or tucked in. Long sleeves should be restrained or rolled up. Visitors to your plant should be briefed on safety and inspected for potential clothes or hair that could be caught before being allowed near the conveyor line.

  • Remove trash, paperwork, and other debris only when power is locked out and tagged out

It is important that the area around your conveyors be kept clean and as free of dirt, oil, etc. as much as possible to ensure the equipment continues to operate efficiently. However, it is unsafe to do that cleaning and maintenance when the conveyor is powered and operating. Beyond that, you should familiarize cleaning crews with conveyor safety as well as your conveyor operators, pickers, packers, etc.

  • Ensure that ALL controls and pull cords are visible and accessible

In case a conveyor needs to be stopped suddenly, all the controls and pull cords need to be easily accessible and plainly visible so that anyone working in the area can reach them.

  • Know the location and function of all stop and start controls

For the same reason, anyone who regularly works in a conveyor area must be familiar with the location and function of stop and start controls. The controls must be marked to avoid confusion and allow people to make fast decisions on using them. Training should be given to all employees about the controls, where they are, when to use them, and how to access them. It is best if this fundamental safety training is repeated frequently, and especially so if you reconfigure your plant, change layout, or update equipment.

  • Report all unsafe conditions. Jams should be cleared ONLY BY authorized, trained personnel

You should have a culture of safety around your conveyors that encourages workers to report unsafe conditions like loose guards, people working too closely with the conveyors with unrestrained clothes or hair, etc. Training about safety issues and when to report them should be made to all employees and repeated often. Untrained people trying to clear conveyor jams can result in unsafe situations as well as damaged equipment. Workers should be trained to call facility maintenance to clear jams.

Safety Messages