Conveyor Equipment and Systems
Conveyors are machines and equipment which carry ingredients, products, containers, packs or packaging components from one place to another.
What are the main types of conveyor systems?
There are a large number of different types of conveyor, designed to convey different types of product or to perform particular tasks. They can be divided into four main groups:
- Conveyors for bulk products (e.g. powders or free-flowing solids)
- Conveyors for both bulk products and small unit loads
- Conveyors for small unit loads (e.g. bottles or cartons)
- Conveyors for large unit loads (e.g. pallets or kegs)
In their simplest form, conveyors are mechanical assemblies which can be demountable and easy to move. In their most sophisticated form, conveyors can be complex machines with drives, controls and sensors. In this form, they undertake complex tasks or those requiring highly accurate sorting, ordering or distribution of the items or products being conveyed.
What are conveyors used for?
Common forms of belt and slat band conveyors are used for all types of semi-automated or automated processing and packaging functions. They facilitate different requirements during production, and enable different products and packaging functions to be handled.
Some machines, such as large bakery ovens, include conveyors as part of the process, while high speed wrapping machines require in-feed and out-feed conveyors to be built in to operate at the speeds required.
Different product consistencies (i.e. soft, sticky, hot, chilled, frozen, delicate) require different handling techniques and, therefore, different designs of conveyor.
Packaging containers and components also need to be sorted or orientated, combined, indexed or unscrambled prior to being presented to the packaging machine, or to bring products packed on different lines together. Specific types of conveyor have been designed to achieve all of these functions.
How to keep conveyor clean
The ability to clean conveyors is an important requirement, particularly in food or pharmaceutical plants where rigorous clean-in-place and wash-in-place regimes exist. These conveyors are often made of wire mesh, plastic mesh or stainless steel, and some can be dismantled or moved for ease of cleaning.
Conveyors for Bulk Products
Conveyors moving bulk products are often used for the purpose of filling or emptying IBCs (intermediate bulk containers) and may utilise buckets, roller chains, belts, vacuum pipes or metal screw systems.
Belt Trough Conveyors
Belt trough conveyors use a belt formed into a 'U' shape to convey powders and free-flowing solids. These conveyors can convey products at high speed.
Bucket Elevators
Bucket elevators comprise a series of buckets supported by a pair of roller chains. These conveyors can convey a wide range of products horizontally and vertically and are useful for elevating products where floorspace is limited.
Drag Link Conveyors
Drag link conveyors convey powders and free-flowing solids by pulling a series of links attached to a roller chain through a 'U' shaped metal trough. These conveyors can convey products in one direction and up small inclines.
Flexible Screw Elevators
Flexible screw elevators convey powders and free-flowing solids through a flexible plastic tube by rotating a spiral-shaped metal screw in the plastic tube. These conveyors can convey products at steep angles and do not have to be straight.
Flighted Conveyors
A flighted conveyor comprises a series of plastic elements which link together to form a series of pockets. These conveyors can convey a wide range of products up moderately steep inclines.
Rope and Disc Conveyors
A conveyor comprising a series of discs attached to a wire cable, which are pulled through a race-track assembly of metal tubes. These conveyors can convey powders and free-flowing solids up moderately steep inclines.
Screw Conveyors
A screw conveyor comprises a metal helix which rotates in a metal tube or trough. These conveyors can convey a wide range of products, including sticky products, up moderately steep inclines.
Vibratory Conveyors
Vibratory conveyors comprise a metal trough or tube set at a slight angle, transporting products by vibrating the metal trough or tube. These conveyors can convey powders and moderately free-flowing solids, and are used frequently in situations where it is desirable to spread out the product in an even layer.
Vibratory Elevators
A conveyor comprising a metal trough formed into a helix which elevates products by vibrating the helix. These conveyors are used to elevate free-flowing solids or packaging components through short distances.
Pneumatic Conveyors
A conveyor comprising a series of metal tubes which conveys powders or free-flowing solids using air pressure or vacuum. This type of conveyor can be used to convey products horizontally, vertically or around bends over relatively long distances within the same system. Particularly suitable for dusty products.
Elevating Conveyors
'Elevating conveyor' is a general term applied to any type of conveyor that elevates a product.
Conveyors for Products and Small Unit Loads
Belt Conveyor
A belt conveyor is formed of an endless flat belt which is driven by a mechanical drive and motor. The width of the belt can be varied to accommodate the type of product being transported. Belt conveyors are usually low to medium-speed devices and configured in a straight line.
Belt Bend Conveyors
A belt bend conveyor takes products around a bend. They are made for the purpose of conveying products on a line comprising angular bends of, for example, 45°, 90°, or 180°.
Flighted Belt Conveyors
Flighted belt conveyors are fitted with flights to stop products from slipping back.
Wire and Plastic Mesh Conveyors
Wire and mesh conveyors are made in the same manner as belt conveyors or belt bend conveyors, but using wire mesh or plastic mesh in place of a plastic belt. These designs are used for a variety of reasons, such as allowing for liquids and small particles to fall through the conveyor for ease of cleaning and improved tracking.
Conveyors for Small Unit Loads
Slat Band Conveyors
A slat band conveyor comprises a series of slats linked together to form a continuous flat surface. The slats can be made of stainless steel or plastic, and articulate in one plane for straight conveyors or in two planes to allow products to be taken round a corner. The main application for slat band conveyors is to convey bottles and cans where very low friction between the slat band and the product is particularly important to prevent the products from falling over.
Air Conveyors
Air conveyors move products on a cushion of low pressure air. Conveyors of this type can be used to move cartons and also empty PET (polyethylene terephthalate) bottles supported by their necks. The main advantage of this type of conveyor is its ability to hold large a number of products on the conveyor, but with the minimum of crushing effect on the products.
Accumulation Conveyor/Table
An accumulation conveyor/table comprises a series of slatbands or a plastic mesh conveyor used to store products in a production line. Typically, the size and shape of the accumulation conveyor depends on the amount of accumulation required and the available space on the production line.
Combining/Converging Conveyors
A combining/converging conveyor is an arrangement of conveyors, e.g. slatband, plastic mesh or belt, that combines products from several lanes into a smaller number of lanes, or a purpose-built machine which performs the same function.
Single Liner
An arrangement of slatband conveyors which moves rigid containers, e.g. bottles or cans from a conveyor, where the containers are in several rows, into a single line of containers.
Dividing Conveyor
A dividing conveyor is purpose-built to accept a single line of products and divides them into a predetermined number of rows.
Gripface Belt Conveyors
In inclined belt conveyor fitted with a rough belting material which allows transit packs to be elevated, typically at an angle.
Indexing Conveyors
An indexing conveyor moves and then stops for a predetermined length of time to allow either a particular task to be performed or to syncronise with a machine.
Driven Roller Conveyors
A roller conveyor comprises a series of rollers arranged in a flat bed of varying width and length. The rollers can be driven directly from their ends by a series of chains and sprockets or indirectly using poly-cord belts powered from a line shaft or a belt conveyor running under the rollers. These conveyors are particularly suitable for conveying plastic trays and transit packs.
Gravity Roller Conveyors
A roller conveyor comprising a series of rollers that freely rotate and are set at a slight angle. These conveyors are used to accumulate plastic trays and transit packs.
Magnetic Conveyors
A magnetic conveyor comprises a belt conveyor running over a permanent magnet, allowing tin-plated steel cans to be moved at high speed and at steep angles without the cans falling over.
Skate-Wheel Conveyors
A conveyor comprising a series of skate wheels that freely rotate and are set at a slight angle. These conveyors are used to accumulate plastic trays and transit packs.
Spiral Conveyors
Spiral conveyors are belt conveyors manufactured in a similar way to a belt bend but arranged in a helix. Spiral conveyors can elevate products like transit packs using a relatively small footprint.
Conveyors for Large Unit Loads
Crate Conveyors
Crate conveyors are designed to carry full or empty crates. Typically, the crates will be supported by and moved on a pair of large link plastic chains or a pair of slat band conveyors.
Keg Conveyors
Keg conveyors are designed to carry kegs or drums. Typically, the kegs or drums will be supported by and moved on a pair of large link plastic chains or a pair of slat band conveyors.
Pallet Chain Conveyors
Pallet chain conveyors use two or more driven roller chains to support and move the load.
Pallet Inverters
Pallet inverters are machines which can rotate a pallet load through 180° to transfer the products on the pallet onto a second pallet.
Pallet Roller Conveyors
A pallet conveyor comprises a series of driven rollers to support and move the load.
Pallet Stacker
A mechanism which can stack one pallet load on top of another.
Pallet Turntable
A mechanism typically comprising a short section of pallet roller conveyor which can accept a pallet load from one conveyor, rotate through 90° and then discharge the pallet load onto a second conveyor.
Right Angle Transfer Conveyor
A mechanism typically comprising a short section of pallet roller conveyor which can accept a pallet load from one conveyor, lift the load a short distance above the rollers using two or more roller chains which move up between the rollers, and then discharge the pallet load onto a second conveyor set at right-angles to the first conveyor.
Transfer Car
A machine typically comprising a short length of pallet roller conveyor supported on railway wheels which run on a pair of rails. The transfer car accepts one or more pallets onto the car and then moves sideways to the required out-feed position where the pallets are discharged.
Common Terminology for Conveyors
- Accumulation capacity
- Belt
- Bucket
- Chain
- Drag Chain
- Elevator
- In Feed
- Linear speed
- Mesh
- Out Feed
- Residence time
- Screw
- Traffic Area
- Transport Area
- Traction Element
- Transfer Device
- Transfer Car
- Roller
- Wire Belt
- Working Area