What Are Conveyor Belts?
Conveyor belt systems are mechanical devices that transport objects, they are common throughout all industrial applications. Generally conveyors are used in most material handling industries for transporting bulk materials.
Conveyor belts consist of a continuous loop of belt wrapped around and driven by one or more pulleys (known as drums) and powered by an electric motor. A metal plate bed or rollers normally support the belt from the underside. The pulley that is powered is called the drive pulley, whilst the unpowered is known as an idler pulley.
The frame construction of a belt conveyor usually consists of a metal such as powder coated mild steel or stainless steel for example. The belt or conveyor surface belting itself is available in a wide range of materials, such as plastic, leather, rubber, and also coated fabric. Usually the belt is manufactured from several layers of material, the structural or strengthening layer of which is known as a carcass. For example, in fabric coated belts cotton is often used for the carcass, whilst the cover material might be PVC.
Why Are Belt Conveyors Used?
Conveyor systems remain popular due to their time and labor saving benefits. The manual handling of materials reduces when using a conveyor system. As a result, much more efficient transport of large volumes of goods is achieved, allowing for higher volumes to be processed.
The use of conveyors is also space efficient, as less space and personnel is needed to move the items. As a result transporting products between stations in production and processing lines is simple and efficient with a conveyor.
Some industries and businesses may require only part-time or occasional use of a belt conveyor. A landscaping company or builder for example may need to hire a belt conveyor to clear their worksite more efficiently.
The belt conveyor system is also very versatile and can transport a wide range of objects, of all shapes and sizes. It is generally less expensive than other conveyor systems. Conveyor belts are also useful in instances where the use of a roller conveyor system for example would be unsuitable due to items being too light, having irregular bottomed surfaces, or also being too small. Consequently, these items may not move, could slip, or even get stuck in the rollers.
Environments where you might find belt conveyors:
- Mail sorting, Packing, and Parcel Depots
For fast distribution of products
To move coal, ores, or salt
- In Airports
Used in baggage handling
- Paper mills
To transport wood chips and also pulp
For moving crops, grain, or bales
- Warehousing & Distribution
To transport stock to and from delivery area
- Waste & Recycling Centres
For sorting refuse
When transporting sand, also used in shot blasting
- Production & Manufacturing
For moving parts, stock, and also dispatching goods
What Are The Different Types Of Belt Conveyors?
Whilst most people are familiar with the standard horizontal conveyors as seen in supermarkets, there are many other types of belt conveyors manufactured to suit specific applications.
Belt conveyors are available to suit all environments and applications. Belt conveyors can be manufactured to be able to transport goods around corners, whilst incline belt conveyors can transport items between differing height levels.
In most cases most manufacturers build to suit the conveyors industry application. For moving products across short distances or within buildings, a general material handling belt could be used. For farming, mining, and other industries that produce large quantities of materials, a bulk material handling belt would be required.
Whilst belt conveyor systems can seem quite complex, many of the conveyors can be seen in a modular sense. It’s a case of building a complex system from relatively simple components. The key thing is to partner with a conveyor manufacturer or supplier who understands your industry and applications, working environment, and products. Consequently they will be able to piece together the perfect belt conveyor solution.
The different types of belt conveyor include:
- Modular Belt Conveyors
- Slat conveyors
- Portable Conveyor Belts
- Swan Neck Conveyors
- Metering Conveyors
- Sandwich Belt Conveyors
- Pipe Belt Conveyors
- Trough Conveyors
Below you will find further information on each of these types of conveyors, you can also read our guide to determine what type of conveyor you need.
Modular Belt Conveyors
A modular belt is made up of chains of interlocking plastic pieces which allow for the belt to move around corners and bends. It is useful as it allows for a wide variety of products to be conveyed. Items with sharp edges for example are unlikely to damage the modular belt in comparison to standard fabric based belts.
It also allows for liquid to drip through the conveyor when dealing with wet products or for when the conveyor needs to be cleaned. Therefore this makes them especially suited to food production line conveyors.
These are similar to a belt conveyor however it uses slats or plates on roller chains to transport goods. Slat conveyors are primarily used for the transportation of heavy or large objects. A purpose built slat conveyor suits much more hard wearing applications, where a standard belt would not withstand heavy duty use.
Portable Belt Conveyors
Portable conveyors are useful to aid in loading and unloading vehicles, railcars, and also silos. Packaging facilities also make use of conveyors with casters, allowing for movement required.
Swan Neck Conveyors
An example of an elevator belt, often used to carry items upwards into a hopper or delivery system. As these conveyors are built on an incline, they can also be used to create a bridge in the conveyor system. Elevator or incline belt conveyors also elevate loose materials. These have spaced partitions with shelves or buckets that the material rests in, these allow for the conveyor to carry the material upwards.
This type of conveyor allows for the separation or accumulation of items. Often used prior to sorters and merges in the conveyor system. As the items are separated, then assessed using sensors to determine the items width, or to allow space in between items if a minimum gap is required for the next step of the sorting process.
These metering conveyors must be made with durable components to withstand many stops and starts. The products can also be weighed with the inclusion of a beltweigher into the conveyor system.
Sandwich Belt Conveyors
These differ from the standard design in that it uses two conveyors as opposed to one. These two belts are placed face to face, therefore allowing for the material being transported to be held (or sandwiched) firmly in between them. This allows the material to travel up steep inclines.
Pipe conveyors have a belt which rolls together to form a tube or pipe. The use of idler rollers around the outside of the belt maintains the circular shape.
A pipe conveyor is desirable for environments where space is extremely limited, or relatively steep inclines or bends are required. They are used in industrial applications where material spillage is undesirable.
Troughed Belt Conveyors
Troughed conveyors have a belt shaped in a trapezoid (or trough) like manner. It has these edges to ensure the material remains contained. Similar to the pipe conveyor, the idlers are what allow the belt to keep it’s trough shape due to their angled placement.
If you are interested in a conveyor system from Spaceguard, you can find our belt conveyor products page here. Please feel free to contact the helpful Spaceguard team if you have any questions regarding our products.
Belt Conveyor Specification
The specification of the belt conveyor is normally dependent on the application, industry, and product type. Manufacturers of bespoke and custom belt conveyor systems will ask about what the end usage of the conveyor will be, this is to ensure the conveyor system is built to suit that application. Things you should consider include the maximum load capacity, the conveyor belt system speed, throughput, the frame material or shape, and also drive configuration.
As well as this the type of product or material to be conveyed must be considered. Conveyor belts for the food industry for example must be suitable for washdowns and disinfecting. These conveyors often have a blue belt material, to denote they are washdown suitable which is a requirement of food hygiene laws. The belt surface itself also needs to be resistant to scratches or damage, as that could harbour bacteria.
Another consideration for your belt conveyor supplier is static electricity, as conveyor belts can generate static as they travel around the pulleys. Where static sensitive components need to be conveyed, this could be harmful to the product. A conveyor belt manufactured with anti-static technology, for example conductive belting, or static control brushes solves this problem.
Some items may be sensitive to vibration, pressure, or could be hazardous materials. These should therefore be discussed with the conveyor manufacturer so they can counter risks, thus ensuring the conveyor designed is fit for purpose.
The environment the conveyor will be running in is also important as humidity or temperature can affect operation. Consequently the conveyor needs to meet certain specifications to be able to continue optimal performance.
What About Conveyor Safety?
Conveyor systems have different safety requirements depending on the usage & environment. The belt conveyor manufacturer should ensure that any risks are properly accounted for, and any workplace safety regulations are also adhered to. Industrial belt conveyors should be fitted with start-stop buttons, they can also be set up with remote stops. They can also have belt sway switches, which will stop the conveyor if the belt loses alignment.
If the belt conveyor is moving at a speed other than what has been specified, a speed switch can stop the belt to ensure the users, products, and the belt itself do not become damaged. If the belt however does become damaged, a belt rip switch is triggered. Fitted guards ensure products remain on the conveyor system when moving goods on an incline.
Conveyor systems controls can be as simple as on and off, or soft-starts which cushion loads on start up. Variable frequency drives also control the speed and acceleration of the motors.
History & Facts
- 1892 - Thomas Robins’ inventions led to the development of conveyor belts.
- 1913 - Henry Ford introduced conveyors into the Ford Motor Company factory.
- 1972 - Friedrich Krupp GmbH built the longest conveyor belt system in the world at 61 miles / 98 km.
- 2008 - Siemens installed the longest airport conveyor system at the Dubai International Airport. It measures 39 miles / 63 km.
Commonly used Conveyor belt Terminology
- The bed is a steel section of framework the belt runs on.
- You would need to know the length of the conveyor required.
- Also the width of the overall frame, also the belt width.
- A belt clip is a mechanical fastener which joins both ends of the belt
- The endless length of the belt is the belt length
- The Belt Scraper clarifies the section fitted to underside of belt and scrapes off debris
- Importantly you would need to know the speed of the conveyor.
- Brake motor is used on an incline to brake the belt. It prevents the conveyor rolling back.
- Castors: Wheels normally used to move the conveyor around.
- Ceiling hanger: Type of support used to suspend the conveyor from the ceiling.
- Centre drive: Position of drive motor, normally underneath on longer conveyors - or small end pulley belts.
- Control panel: Enclosure with the electrical components to used power and control the conveyor.
- Crowned pulley. A machined angled to the surface normally of the drive and idler rollers.
- Decline conveyor: Conveyor used for downhill transport - normally fitted with grip face belt.
- Drive: Either geared motor of drum motor - used to transmit power to the belt.
- Drum motor: Drive motor built in the pulley.
- Emergency pull cord: Length of coated wire stretching the length of the conveyor. Works like a emergency stop button
- Emergency stop button: Push button used to stop the belt in an emergency - (requires a safety relay within the control panel).
- Flow: Direction of conveyor.
- Guide rail: Either fixed or adjustable bars or plates used to either contain or to guide the product on the conveyor.
- Idler pulley: Non driven roller.
- Inclined conveyor: Conveyor transporting product up a slope.
- Lagged pulley: Rubber material bonded to the surface of the drive pulley to increase friction.
- Motor: Normally electric, used to power the conveyor.
- Photo electric cell: Electric control device used to sense a product on the conveyor.
- Pop out roller: A gravity transfer roller fitted to the end of the conveyor. Designed to eject if something's dragged in.
- Power feeder: Horizontal section fitted at the top and bottom of an incline conveyor, used to transfer products from incline to horizontal.
- Pulley: Drive and idler pulleys - rollers at the end of the conveyor.
- Shaft mounted: referring to the geared motor type and position when using a hollow bore geared motor.
- Slider bed: Same as bed.
- Snubbing roller: Fitted to the underside of the belt, used to track the belt.
- Support: Steel fabricated structure, used to position the conveyor at the required height.
- Tail Pulley: Non drive end pulley.
- Take up: Jacking mechanism to put tension onto the belt.
- Under guard: Sometimes fitted to the underside of conveyors to prevent access to the underside of the belt. Can cause nip points.
- Variable speed: Means of adjusting the speed of the belt - normally inverter within the panel.