The robust Ishida CCW-RV series weigher has provided high accuracy in extreme conditions for a frozen vegetable processing line in one of Europe’s most productive vegetable growing areas.
A 24-head model from Ishida’s top-of-the-line RV multihead weighers is achieving pinpoint accuracy when weighing of mixed frozen vegetables. The CCW-RV-224 is being used for three-mix, two-mix, and single products for fill weights of between 14oz and 53oz (400g and 1,500g) with high accuracy to within 0.1g of target at speeds of up to 95 packs per minute.
Many of the products, which are later sold as ingredients or complete dishes, take freshly harvested crops that are carefully processed and frozen straight away. They are then mixed according to precise requirements in advance of the filling process. It is critical to ensure each pack’s mix component percentage is accurate both to meet customer requirements and to satisfy statutory product composition regulations.
“Being a premium supplier, we wanted to enhance product quality with regard to mixing ratios while retaining high throughput rates,” explains the production manager. In addition, the company was looking for a solution that could deliver greater flexibility to allow it to expand its product range.
For mixed product applications, one or two separate vegetables are added to a pre-mixed main component. These additional items are either particularly expensive or important for the distinct flavor of the finished product. In addition, some vegetables, such as broccoli and beans, tend to separate from the mix so they are added separately at the filling stage. The top of the weigher is divided into separate mix sections to handle the individual products, with loadcells regulating the feed to ensure an even flow throughout the weigher. Vegetables are first fed to the pool hoppers, which hold the product for a short time before transferring (on demand) to the weigh hoppers below. It then takes a fraction of a second for the microprocessor to calculate the best available combination of quantities for the target weight in each section.
The weigher also features a third row of booster hoppers, which provides temporary storage of already weighed but not yet selected product. This additional layer increases the number of weight combinations available for each calculation. A high-speed discharge chute with anti-swirl fins transfers the precisely dosed portions of different vegetables, without delaying the process. The different components are then merged in a timing hopper before being discharged into bags as a compact product charge.
Thanks to the Ishida weigher’s ability to exactly meet the specified mixing ratios, the company added new mixed vegetable varieties to its range. The weigher is currently being used to pack a total of 40 different products with operators carrying out product changeovers (once or twice per day) by calling up pre-sets on the weigher’s remote control unit.
In addition to its precise mixing accuracy and high throughput rates, another key benefit of the weigher is its exceptionally robust construction. The Ishida CCW-RV has been designed to meet the extreme demands of frozen food applications with all contact surfaces made of sturdy, embossed sheet metal and incorporates extremely high levels of water resistance to cope with frequent temperature changes. The IP66-, IP67-, and IP69K-certified, sloped-surface and hygiene-friendly construction means all parts of the weigher, including the drive units, are highly protected against water ingress during high-pressure and steam jet cleaning and enable liquids to run off, preventing the build-up of product or residue.
“The fact that the weigher is water-resistant is very helpful and was definitely one of our reasons for choosing Ishida,” confirms the facility’s production manager “It means that the equipment is protected against damage from both the damp production environment and the daily wet-cleaning.”