Frozen vegetables are convenient and consumers have a growing appetite for them. Frosta AG is a premium supplier in this segment and has now been able to further increase their product quality. Since recently, the vegetable mixtures are packed with an Ishida multihead weigher, which gives the company the option to allocate some components even more precisely. So the manufacturer strengthened the brand and also opened up opportunities for the portfolio.
Halfway between Leipzig and Dresden lies the Lommatzscher Pflege, one of the best vegetable growing areas in Europe. Frosta AG maintains the production site Elbtal Tiefkühlkost, which specializes in vegetables. In the factory, the freshly harvested crops are processed and then frozen immediately. Many of the products that are later available as supplements or as whole meals in the trade, must be mixed beforehand, to exact specifications. Only if the right mix is delivered in every package, every time, will the customers be satisfied and will any legal requirements with regard to the product composition be met.
Left: Premixed vegetables and beans as a monocomponent on their way into the bowls of the multihead weigher
Right: The CCW-RV multihead weigher in use / Images: Ishida GmbH
Suitable mixing ratios at high cycle rates
In the fall of 2018, Frosta installed a new high-performance packaging line for the frozen vegetables. Production Supervisor Marius Schwerhoff explains the background to the investment: "As a premium supplier, we wanted to further increase product quality in terms of mixing ratios, and at high cycle rates."
At the same time, the manufacturer of the technology expected more flexibility to expand the product range. A mixed application with a model character had previously been implemented in Bremerhaven's main factory, Frosta. "There we have had very good experiences with a multihead weigher from Ishida," said Marius Schwerhoff. That is why the chose this manufacturer for the Elbtal frozen food location as well.
The multihead weigher of the high performance Ishida CCW-RV series can handle a wide product range with its 24 heads. Frosta uses the machine equally for 3-Mix, 2-Mix and Mono products. In the case of mix applications, a premixed main component is enriched with one or two additional components. The latter are can -for example- be particularly expensive or taste-characteristic to the finished product. Some vegetables, such as broccoli or beans, also tend to segregate and are therefore added separately during packing.
A scale for each product component
The frozen vegetables will reach the multihead weigher from above. The feed hopper, like the distribution plate, the trays and the discharge hopper, is divided into three sections so that the product components are processed completely separately. Load cells in the distribution plate segments regulate the supply to the radial troughs, guaranteeing an even product flow.
The vibrating gutters transport the vegetables to the pre-shells, which briefly pick up the product and then feed the buckets underneath. As soon as a weighing pan is empty or needs more product, a signal goes to the corresponding pre-bowl. The microprocessor calculates the optimal subset combination for the target weight in fractions of a second. A third ring with booster shells is used for intermediate storage already determined subsets, which the Combination options multiplied further. The precisely dosed vegetables are discarded by means of a high-speed discharge hopper with dividers, which prevents the product from spinning over in a process-delaying manner.
Below the scale, the product components are combined in a collecting storage tray and dropped into bags with filling weights between 400 g and 1500 g. Weights can be eliminated via a separate storage shell. Depending on the nature of the product, Frosta achieves an output of up to 95 weighings per minute with an accuracy of 0.1 g. The predetermined mixing ratios are optimally met, which also led the manufacturer to include new vegetable mixtures in his assortment. Currently, 40 different products are packed with the multihead weigher. The product changes -occurring once or twice a day- are done by calling up pre-settings at the push of a button.
Unique moisture protection
Frosta's requirement profile for the new multi-head weigher not only aimed for extreme accuracy of the mixtures at high cycle rates. They also demanded an extremely robust construction.
Production Manager Marius Schwerhoff: "The moisture protection is very helpful and was definitely a criterion for this investment decision." Thus, neither the wet production environment nor the daily wet cleaning can cause damage to the technology. "The hygiene-friendly design facilitates the drainage of liquids and prevents product adhesion and dirt deposits.