Conveying systems are the driving force of most packaging operations and play a significant role in their efficiency as Steve Thomas-Emberson reports
Conveyors are the arteries of packaging systems, pumping the life-blood of products around the various stations, from delivery point to distribution warehouse. Get this part of the operation wrong and the knock-on effect will be felt throughout the packaging process, damaging efficiency and ultimately reducing margins.
Moreover, investment in sophisticated – and in many cases bespoke – systems combined with automated handling systems can significantly improve efficiency while reducing labour costs.
As in many machinery areas, one trend is the use of a single-supply source to provide complete handling systems and it can make good sense to appoint the conveying supplier with this task as it is that company’s products which provide the interfaces with ancillary equipment.
An excellent example of this is the recent installation of a fully integrated handling system at the warehouse of Retail Variations – a group which includes retail businesses such as Past Times, Hawkshead, Manners, SF Cody and Ocean Home Shopping – by Oldham-based Peer Conveyors.
The conveying system for the distribution depot handles cartons and plastic tote boxes of goods from the vehicle unloading bay and storage areas. Incoming goods are transported via an operator-input station, scanned and diverted electronically to bulk storage located at ground level and on two mezzanine floors.
Peter Holding, project manager at Retail Variations, says: “Against stiff competition, we finally selected Peer Conveyors because they demonstrated a clear understanding of our needs. During initial discussions with another conveying company, they openly admitted that they could not develop our ideas and undertake the necessary project planning as required so they recommended that we contacted Peer Conveyors.
“Its system proposal was competitive and, more importantly, met our criteria and system functionality requirements in terms of volume throughput and carton handling size/capability. The system design also provided Retail Variations with the flexibility to extend the conveying system to meet future expansion. There was also the additional advantage of Peer Conveyors providing a ‘one stop source’ service.”
Incoming cartons weighing approximately 12kg are barcode labelled for identification and tracking, and placed onto a low level 12m gravity roller conveyor to be manually fed onto an incline belt conveyor. The cartons transfer to a high-level powered lineshaft roller conveyor to be transported along the main building wall towards the bulk storage area where they are identified by scanner and automatically routed via a chain transfer unit and incline/decline belt conveyors to one of three floors.
At each level product feeds off the conveyor belt onto a 3m section of gravity roller track for manual loading/unloading as required. All powered roller and belt conveyors supplied are reversible to provide for maximum system flexibility.
Product is picked from bulk store on floors one and two to replenish stock for despatch at ground floor level. On both upper floors, plastic order pick containers are manually loaded onto a lineshaft conveyor incorporating a 90° bend, feeding onto a decline belt conveyor to deliver the goods to ground floor level.
Holding added: “Working within a large multi- purpose 230,000ft² site and at different levels, it was vital to the success of the company that product flowed smoothly and without risk in terms of health and safety. The conveyors have provided us with this and can be expanded and updated as volumes increase. Throughout the project, Peer Conveyors liaised closely to ensure that installation and commissioning was completed with minimum disruption to day-to-day operations, and it was completed on time and within budget.”
Building relationships between client and conveyor company is common and an excellent example of this is the partnership between Würth UK, a stockist of construction fittings and automotive components, and Keymas. The requirement from Würth was for a zero pressure accumulation conveyor line. Keymas reviewed the company’s existing conveying equipment and proposed to upgrade and enhance the existing line shaft by utilising its own latest control circuitry for control of 24V brushless motorised rollers.
“Our customers now insist on designs that are easy to clean down, run efficiently and are precisely sized for the duty required”
Each conveyor zone has one motorised roller and sensor linked to the logic control board. Each board is then plugged into the adjoining zone circuit board in order to communicate zone status and create zero pressure accumulation.
The decentralised method of conveying allows ease of conveyor design together with the ability to add extensions and modifications. This system’s inherent flexibility allows Würth the peace of mind for the future knowing that whatever their needs the system can adapt – a keen element in all conveying systems.
Some products have particular handling problems and bespoke systems are typically the best way to overcome them. Conveyor Systems, based in Swadlincote, Derbyshire, has, for example, designed, manufactured and installed a specialist conveying system to handle nasal sprays for a leading multinational pharmaceutical company. The challenge was to provide an efficient handling system to convey very small polyethylene spray bottles [300mm diameterx105mm tall] upwards and overhead through cleanroom conditions, at speeds of 200 bottles/min. Matters were not helped by the packs’ smooth surface and small footprint base, making them unstable to transport on conventional conveyors.
Conveyor Systems’ answer was to design into the system two strategically positioned ‘fallen bottle chicanes’. These were built into the slat conveyor at either end to evacuate and capture fallen bottles. Each side grip conveyor is then powered by two SEW geared motors to maintain a positive but gentle grip of the bottles.
Within the conveying market there are some highly specialised companies such as Guttridge Services which manufactures bulk powder handling conveyors and elevators. One of its Multiflo 100 tubular screw conveyors has been installed at Rentokil’s chemicals packaging factory at Kirkby, Liverpool. This advanced machine, which is inclined at a 37° angle, features an integral loading hopper with agitator. An agitator was necessary to ensure that materials with poor flow characteristics could be easily handled. This system is used to pack pesticides, rat poisons and other chemicals as part of Rentokil’s packaging services. Handling any chemicals in safety is essential and this system makes compliance with the COSHH regulations easier to maintain. As Peter Guttridge, managing director, commented: “Our customers now insist on designs that are easy to clean down, run efficiently and are precisely sized for the duty required. There is always a relentless push for lower prices and, as a result, investment in machines and computer systems helps to make us as efficient and up to date as possible.”
“New generation” spiral conveyors
Fresh on the market is a “new generation” of hygienic spiral conveyors from Yorkshire-based Conveyor Belt Technology. The space-saving configurations are assembled from a modular stainless steel framework and use a modular belt which is said to be easy to maintain and clean.
“The spiral conveyor enables the continuous, smooth, vertical transfer of product between different levels without the problems associated with inclined belts or lifts”, says CBT managing director Steve Harker. “These low cost, low maintenance units are ideal for emptying high level spiral freezers and for applications where hygiene is paramount.”
The conveyor provides belt speeds of up to 30 m/min and can bridge heights up to 5m. Available in both up and down configurations, the units use one motor combined with a lightweight belt to keep power consumption low. The conveyors can also be configured to provide an intermediate storage or buffering solution between packaging equipment.