Automation for greater productivity and food safety
Automation in the meat-processing industry is an important issue. It ensures greater energy efficiency as well as productivity and quality. In addition, it improves hygiene conditions and relieves staff of the heavy physical work. Industrial robots are increasingly proving to be the key to effective solutions as opposed to costly specialised mechanical approaches.
Sortation conveyors and sorting robots
Sortation conveyors work by presorting the goods and temporarily storing the weighed fillets in buffer compartments or interim diverts. Since each buffer compartment requires individual checking for number and weight, this means, as well as complex and costly mechanical systems, the use of a lot of measuring and control technology.
Once the target weight and number have been reached in the buffer storage boxes, the latter drop the products via a trap onto the conveyors beneath, which then take them to the packing line, where there is always a relatively large amount of manual work to be done.
Sorting robots make it possible to build compact robotic units for weighing, sorting and packaging according to pre-determined weights. In addition, they allow rapid changes of format and mixed mode operation.
'Mixed mode' here refers to the parallel packing of chicken fillets in trays, for example, according to a fixed weight and the simultaneous packaging of 'bulk ware' in larger boxes for bulk packs.
The result is that 'cells' of sorting robots with three delta robots can fill trays or boxes in any ratio required. The first two robots pick out the best-fit fillets and fill the trays for the fixed weights with them; the third puts the rest into boxes for the 'bulk packs'.
At the entrance to the 'robot cell', one or more belt scales weighs the fillets on their way from the cutting room. Then the conveyors pass the fillets under a detector which determines their weight, exact location and orientation. From these data, depending on the weight in each case, a sorting algorithm calculates the instruction set for both conveyor belt and robots.
Laser scanners for precise cutting
The joints of meat slices and chops that come from the cutting room differ – some significantly – in consistency, weight and shape. The latter must however be taken into consideration by the slicer, so that it can cut slices of the same weight by varying the thickness from one cut to another.
Laser scanners provide a 3D image of the joints of meat without touching it. Dedicated cutting software calculates the thickness of each slice from the data provided regarding the shape and the overall weight of the joint and controls the progress of the joint through the slicer. Because of variations in consistency (ratio of meat to bone, meat to fat) the slices are still not a hundred percent identical in weight, but significantly more accurate than they would be without the high-tech measuring strategy. And that simplifies packaging by weight for down-stream sortation conveyors or sorting robots.
Packaging secures quality
Packaging is one of the last stages in meat processing and demonstrates the highest level of automation. The high-tech solutions package thighs, chops and steaks, minced, chopped and diced meat as well as marinated, seasoned and oven-ready products (convenience food).
Vacuum, MAP and skin packaging gives products optimum shelf life. Fully automatic tray sealers can package over 100 packs of meat, sausage or convenience products per minute. Increasingly, manufacturers are also integrating high-end processes such as HPP, to increase the shelf life of foods.
HPP shelf life
High pressure processing (HPP), sometimes also called high pressure preservation, is a non-thermal process to render inactive undesirable micro-organisms in meat, poultry and other foodstuffs. The inactivation occurs at pressures of up to 6000 bar (87000 psi) and with processing times of up to 15 minutes.
The pressure, which is applied to all sides of the product, does not harm the product itself, but does change the molecular structure of bacteria, viruses or mould that attaches to it and renders them inactive.
The process increases the shelf live without additional quantities of additives and avoids any loss of quality in terms of taste or nutritional value, such as occurs with the use of heat in conventional pasteurisation.
The future of automation in meat processing lies in the integration of diverse partial solutions, such as linking intelligent laser measurement of chop joints to the production of fixed-weight packs when integrated with sortation conveyors and sorting robots. Another example is to be found in the integration of process-management skills and special processing procedures such as HPP into the packing lines.
The entire gamut of new automated solutions relating to the processing and packaging of meat and sausage products will be showcased by the exhibitors at IFFA from 4 to 9 May 2013 in Frankfurt, Germany.
