As with many other food sectors, the meat processing industry loses a considerable amount of money from wastage throughout the supply chain. But a new weighing system developed by Ishida is claimed to save manufacturers an average of five to 10 grammes of meat per 280g tray, while achieving packing speeds of around 32 weighments per minute.
Payback on the new Fresh Food Weigher system, says Ishida, is estimated to be less than four months.
The main application for the weigher is marinated beef steak, marinated pork steak and marinated pork cubes, packed into thermoformed trays with one or two compartments. The steaks are all packed two to each tray at fixed weights of between 240g and 280g.
The main packaging challenge for the company is the need to find two pieces of steak each time that match the target weight of the pack as closely as possible. Due to the sticky nature of the product, automatic weighing of the meat was not previously possible, as an effective and consistent product flow through traditional multihead weighers could not be achieved.
Operators therefore had to weigh the steak on static scales, resultingin a packing process that was long, labour intensive and caused highlevels of product giveaway.
The Ishida Fresh Food Weigher has now enabled this process to become more automated. The machine features a linear arrangement of hoppers but operates like a conventional multihead weigher, where a built-in computer calculates all possible weight combinations and selects the one combination of weights in the weigh hoppers that comes closest to the required pack weight.
The linear configuration allows operators to hand-feed product to a setof linear belt feeders which act as product buffers and provide aconsistent product supply to the pool and weigh hoppers. All hoppersutilise sliding doors. These easily dislodge product residues so thateven freshly marinated beef and pork can be handled comfortably withoutsticking.
Steaks already weighed in the weigh hoppers but not selected for thepack are discharged into another set of hoppers located directlyunderneath the weigh hoppers. This additional set of hoppers frees upthe weigh hoppers to accept more product, thus increasing thecombinations available for the next weighment, which in turn increasesweighing speed and accuracy.
Selected product is discharged onto two collection belt conveyors whichtransfer the meat via a discharge chute into the trays. These conveyorsare fitted with scraper gates which remove small product residues toensure a reliable and consistent product discharge.
Ishida project engineers managed the installation of the entire newline, providing elevating, indexing and belt conveyors and a platformfor the operators.
The customer has been using a circular Ishida multihead weigher inanother part of its operation for around ten years. The accuracy andreliability of this equipment made Ishida the obvious choice for the new project.
Weighing has also become an important ID point in the process flow, and a means by which a manufacturer can trace a particular product. Each formulation or batching step within a production order provides an opportunity to identify and/or mark a particular component.
This is especially important considering the traceability regulations about to come into force in the EU. This legislation, which comes into force in the EU in January 2005, states that food manufacturers have to be able to show that they can trace products right through the food chain.
"Traceability is all about record keeping," said Scot McLeod, Ross Systems vice president for marketing, North America. "It means keeping track of raw materials through to shipping a final product, and everything in between."