Thursday 21st Mar 2019 - Logistics Manager Magazine

Bakery conveyor challenge

With the demand for specialist bakery products expanding, Conveyor Systems Ltd (CSL) was called upon to design an end-of-line conveying system for the packing of various sized bags of flavoured bread rolls into cartons and plastic supermarket trays. The system had to be flexible to meet packaging variation and to achieve this, it involved working very closely with the customer to create the optimum design to install and commission the system with minimum disruption to production.

The project had to provide for maximum flexibility as product is delivered from four bagging lines at speeds of up to 50 bags per minute, in various pack sizes of four, five or six units, to be packed into cartons or trays on two independently operating manual packing lines located on the first floor. The system had to have the ability to feed more product and packaging to either of the two pack stations depending on the throughput and product types.

Both cardboard cartons and plastic supermarket trays are fed from ground floor level. A case erector makes up boxes of various sizes as required, while plastic trays are individually dispensed from stacks, feeding up two continuous vertical spiral elevators to the two packing lines on the mezzanine floor. For maximum flexibility the plastic trays can be split symmetrically between both packing lines or asymmetrically if only one line requires trays. The system is so configured that both trays and cartons can be packed at the same time. From either of the spiral elevators, trays or cases are fed along powered roller conveyors, which are positioned one either side of a central conveyor carrying bags of products, for packing by several personnel located on each line.

From a hygienic aspect, CSL designed the system to keep the case erector and tray feed at ground floor level to avoid wooden pallets/dollies entering the packaging area and prevent any possible contamination.

Bags of product feed from four bagging lines via elevating belt conveyors, which all have manually operated stainless steel dividing chutes to allow product to be split to either of the two packing lines, depending on production requirements. On exiting, the products are guided accurately to maintain orientation for easier packing. All conveyors on this first floor level are manufactured from a clean-line hygienic stainless steel.

Bags are transported along a central 13m long laned, 900mm wide, stainless steel framed modular plastic slat, enabling packers from either side to pick and pack into selected case, or trays positioned on the lower powered roller conveyors running parallel to the main line. As part of the requirement, CSL interfaced the conveyor system with four high speed check weighers and metal detectors.

Owing to the continuous oven process, the controls have been configured to allow the upper mezzanine floor conveyor system to run independently of the ground floor system, so that production and packing can continue even if the ground floor system is emergency stopped.

Once packed into cases or trays, the products are transported along the powered roller conveyors via conveyor belts down to ground floor level. Boxes continue on the conveying system through case sealers before palletising, while plastic trays are automatically identified and diverted from either side to be hand palletised or loaded into dollies.