Cheesy feat
September 1st 2008

South Caernarfon Creameries awarded Astec Conveyors a £270k contract to design, manufacture, install and commission a complete conveying system to transfer blocks of cheese, vacuum packed in film or wrap around corrugated cases, from its hillside production plant down to a new purpose-built cool store some 300m away

Because of the terrain, the South Caernarfon Creameries project was challenging as it necessitated product being transported externally through a totally enclosed conveyor system mounted on platforms and walkways, over the dairy building, avoiding site services, crossing a road and spanning a river, prior to feeding into the new cheese reception area.

With so many third parties involved from planning authorities, architects, civil engineers, etc., it was essential that Astec Conveyors took full responsibility for Project Management to ensure minimum disruption to ongoing business and coordinated site operations to complete the project on time and within budget.

A spokes person from South Caernarfon Creameries reported, "Previous to the new system, the fresh cheeses from production were internally transported by lorry to the opposite side of the factory site and involved double handling and additional labour. Therefore, the objective was to improve efficiencies and provide optimum hygienic operating conditions. Astec offered the best solution for our needs, and took the time to plan for the future maintenance and life of the system. They were prepared to look at options and evaluate them, rather than try to push us down a particular road that suited them."

Hygienic cheese conveying system Corrugated cases or vacuum sealed packs of 20 kilogram blocks of warm cheese are fed onto the conveying system at a rate of 3 cases per minute, inspected for open flaps and then either transferred onto the main conveyor system or routed straight on to a reject line for securing and returning to the system.

Product exits from the building onto an exterior conveyor that is designed so that the side frames and underguarding form part of a totally enclosed watertight stainless steel tunnel, with strategically placed windows for visual inspection and checking of system functionality.

The conveyor is located on an overhead 6m high galvanised platform and walkway 1.5m wide (supplied as part of the contract) to facilitate safe and quick access to the system for maintenance purposes. This construction is capable of spanning 15m unsupported and therefore, avoided ground level disruption having to remove obstructions, and assist in spanning the driveway and river separating the existing buildings from the new cold store.

Modular plastic belt conveyors were utilised to provide greater stability in handling product of various temperatures, avoiding tracking problems and provides for a smooth transfer of the 'soft to handle' product to the manual stack down area in the cold store. Due to the soft nature of the vacuum film packed cheeses, part of the design criteria was that the system had to be capable of accumulating product in a non-contact mode. It was therefore decided to incorporate a number of indexing conveyors into the system to ensure that product could be accumulated in a pitched mode without pressure, and specifically to avoid pack to pack contact.

A series of six (5m) belt accumulating conveyors are located towards the end of the system and sequentially pulsed to accumulate pitched products on build back. When the accumulating conveyors are full, the remainder of the transit conveyors are sequentially closed down and a signal is given to the secondary packaging machine to cycle stop. A two line text display gives the operators visual line status information, and telephones located at either end of the system, enable operators to communicate and advise on such things as end of run, etc. The system can accumulate approximately 30 minutes of production which relates to around 90 blocks of cheese, and is sequentially restarted when the build back sensors become clear.

As products enter the new cold store reception they accumulate on a low back pressure chain conveyor, feeding onto a brake metering belt which singulates the cheese blocks to pass through a metal detector, check weigher and labelling machine. On completion the product is discharged down a small section of gravity roller conveyor to be manually unloaded and palletised to go into cold store.

The installation was managed by Astec Conveyors in conjunction with the main civil contractor and all the sections were delivered pre-fabricated to the site to provide minimum disruption to operations, and craned into position onto supporting steel work.

The system is operating 16 hours per day, 7 days per week, 364 days a year and has resulted in many positive benefits, increasing efficiencies, reducing operational costs and providing even greater hygienic standards for South Caernarfon Creameries products.

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