Pictured: Chicken pieces being weighed on the fast and accurate Ishida R-Series multihead weigher. The 2-mix weigher can add two high-value ingredients, or one at twice the speed

Ishida Europe has devised the weighing and packaging requirements for two complete ready meals assembly and packing lines installed at the Buñol, near Valencia factory of leading Spanish producer Platos Tradicionales S.A. The Ishida solution includes tray denesters, conveyors, volumetric fillers, multihead weigher and checkweigher, with the entire operation monitored and controlled by the company's QX-1100 traysealer.

Platos Tradicionales' concept was a production unit able to deliver a large variety of ready meals, and to respond quickly to any demand for new products.  This meant that the two lines had to allow the addition of a wide choice of ingredients with different physical characteristics, with an accuracy that took full account of the value of each material.  Production processes had to be fast, efficient and accurate and every product needed to be of excellent quality in terms of taste, texture and freshness.

Each of the new lines is capable of producing meals of up to five different components, two of which are added via highly accurate multihead weighing. Since any of the components can itself be a premix of many ingredients, this means the versatility of each line is vast.  

At the start of each line, two Ishida denesters feed trays to a twin-lane, chain-and-peg conveyor.  The empty trays first arrive at volumetric fillers used mainly for bulky ingredients, such as rice or pasta. In each cycle, four trays are filled at a time. They then move to another filling station which applies a pre-mixed sauce. The trays are vibrated, to help settle the contents, before moving on to the distribution system below the multihead weigher, through which the most costly ingredients are generally added. These are often the main protein content of the meal, such as meat, poultry or seafood.

The multihead weigher has 24 heads and is equipped with booster hoppers. An Ishida R-Series model, it is divided at the top into two sections, each with its own infeed. It can be set up to provide two accurately weighed ingredients or a single ingredient at up to twice the speed.

The trays pass one further ingredient-adding station before they reach the Ishida QX-1100 Traysealer, where they are sealed under vacuum, converged into a single lane and run over an Ishida checkweigher.

They then proceed to a spiral conveyor, the start of their journey to an autoclave, where they will be retorted at 90°C, giving them a shelf-life of three months. 

The rapid progress of trays through the line is controlled by the Ishida QX-1100 traysealer. It checks for a 'ready' signal from all three filling stations plus the multihead weigher and the denester before moving the chain and peg conveyor forward a set distance. After each pause, the QX-1100 re-checks the upstream equipment before re-starting the conveyor.

Averaging across all products, the 325g multi-ingredient meals are being prepared and packed at 80 trays per minute. For macaroni-based products, for example, it is 85 trays per minute. The efficiency of the Ishida equipment is above 90%, helping to make Platos Tradicionales one of the most efficient ready meals plants in Europe.

In general, for every 100 kg of ingredients Platos Tradicionales is able to deliver a highly impressive yield of 98 kg of packed, ready-to-retail food. The accuracy of the Ishida R-Series multihead weighers has an important part to play in assuring that giveaway is tightly controlled, especially for the more expensive ingredients.  The entire line has also been designed for fast and easy cleaning.