This website uses cookies primarily for visitor analytics. Certain pages will ask you to fill in contact details to receive additional information. On these pages you have the option of having the site log your details for future visits. Indicating you want the site to remember your details will place a cookie on your device. To view our full cookie policy, please click here. You can also view it at any time by going to our Contact Us page.

Delivering high accuracy for fixed-weight vegetable packs

03 June 2018

Swiss vegetable producer, Gastro Star AG, is now able to pack fresh convenience vegetables in fixed weight packs, sometimes at very low quantities, while minimising product giveaway, since installing a new packing line solution from Ishida Europe and its distributor in Switzerland, Itech AG. 

The line is providing accuracy and high availability despite frequent product changeovers, reducing operating costs and offering a fast payback.

At Gastro Star’s production facility in Villigen in the north of Switzerland, vegetables are peeled and pasteurised for fresh convenience products. Vegetables such as beetroot, carrots, celery, potatoes and corn on the cob are available chopped, sliced, diced or whole.

In accordance with a new retail requirement, all fresh produce must now be packed by fixed-weight. The manual weighing previously carried out on two processing lines did not meet this requirement so Gastro Star needed to find an automated packing solution that did not result in excessive giveaway.

Fixed-weight packs are a particular challenge for products with relatively few pieces of whole or large vegetables as the small number of items makes it difficult for a multihead weigher to calculate the right combination. For example, Gastro Star may have to pack three corn cobs into a 480g tray.

The new packing line from Ishida and Itech provides a flexible solution centred on a 14-head CCW-RV series multihead weigher with three different infeeds. Whole vegetables are brought up to the weigher using an elevator; chopped products are delivered to the Ishida using a lift and tip hopper; and pieces of corn cob are fed directly from the chopping operation to the weigher.

The multihead weigher can be moved into three positions on its gantry, which will allow it to fill a second packing station that is still in the planning stage. A third, central position between these two lines enables the weigher to be easily cleaned.

The feed system is readily adjustable to be moved into the different positions to provide quick changeover times. Differently inclined dispersion tables, available for sticky and rolling products, ensure an effective product distribution on top of the weigher. From there, radial feeder troughs transfer the product to the pool hoppers. These then supply a second ring of weigh hoppers that contain the Ishida loadcells. The microprocessor takes just a fraction of a second to calculate the combination of weigh hoppers that comes closest to the target weight.

The Ishida RV weigher was specifically designed for challenging operating conditions, such as Gastro Star’s humid production environment. It has a certified IP69K protection rating with a hygiene-friendly design – in accordance with EHEDG (European Hygienic Engineering & Design Group) standards – that allows liquids to run off and prevents the build-up of product residues. For example, the hoppers have large corners to stop product residue from accumulating, while the stainless steel contact parts are impervious even to the fruit acid contained in Gastro Star’s products. For cleaning, hoppers and feeder troughs are removed without tools and cleaned at a wash wall next to the weigher.

The line is operating continuously throughout two shifts. “We benefit in particular from the multihead weigher’s excellent accuracy,” said Peter Gisi, production manager at the plant. “For example 400g packs of potatoes are overfilled by less than 1 g, and 1kg packs of diced beetroot by an average of just 0.032 g. Another advantage is the packing line’s high availability as the frequent product changeovers and line cleandown can be carried out quickly.”

The operating cost of the line has been reduced by two-thirds compared with the previous packing line. Johann Meier, who was responsible for equipment purchase and process optimisation at Gastro Star, expects the packing line to pay for itself within 2.5 years.

Contact Details and Archive...

Print this page | E-mail this page


Article image What role does refrigeration play in the supply chain?

Controlling the temperature of food across the whole supply chain is vital to extend shelf life. But how much can be gained by food manufacturers through careful monitoring at all process stages?Full Story...

Article image A recipe for continuous improvement success

Suzanne Gill reports on the important role that continuous improvement has to play in ensuring food processes remain profitable in an ever more competitive environment. Full Story...

How to deliver assured air quality for production sensitive sites

Hygienic drainage for food safety

Owning your hygiene culture