With short production runs and a huge product range, a division of Switzerland’s second largest retailer has chosen a single Ishida multihead weigher to handle 70 very different products.

Coop’s Sunray division produces some 55 million units of very diverse packaging each year. As part of the upgrading of its bag-packing facility, and with the help of local Ishida agent Itech, the company has selected a 14-head CCW-RS weigher with plastic hoppers.

Filling mainly flow-wrap or Stabilo-type packs with target weights ranging from 8g to 500g, the new weigher handles many relatively straightforward products such as hazelnuts, almonds and pulses. For more difficult applications – including grains and sticky items -various sets of parts have been provided that can be rapidly substituted for the ‘standard’ components.

For example, when small-grained, free-flowing products such as quinoa are being packed, an enclosed dispersion table with apertures leading to the radial feeder troughs is used. Granular product enters via a vibratory feeder and builds up on the table until it flows out through the apertures at a rate which can be adjusted by narrowing or enlarging them.

For products such as apricots, dates and figs, which tend to cling to contact surfaces, a dispersion table is used which is surfaced with C4, Ishida’s recently-developed ‘easy-motion’ material. Together with a steep, 20° angle, (twice that of standard dispersion tables), this is enough to impel most products, however sticky, onto the radial feeder system.                                                                                                                         

Here the product runs along a special set of feeder troughs, also finished in C4 and tilted by 6°. After weighing, product falls into a steeply angled (60°) discharge chute, giving it sufficient impetus to make it unlikely to stick as it leaves the weigher.

Tightly-closing ‘anti-leak’ hoppers are used for products that contain or generate dust, such as dried mushrooms, or granular products.

The plastic hoppers make for quieter operation when hard products such as nuts are being weighed. They are also of a design, incorporating ridges, which helps reduce sticking. Each hopper has metal pieces built into its fabric so that, in the unlikely event of impact damage any fragments can easily be picked up by the downstream metal detector.

The weigher offers easy access for cleaning and all contact parts can be lifted on or off by hand, an important factor where there are at least one or two product changes per day, each demanding complete cleaning of the entire line.

“As a Swiss company, we are faced with the specific challenge of having to produce small runs of different products,” explained Dominik Leder, head of product finishing at Sunray. “The Ishida weigher is indeed an all-rounder. Sunray has become more flexible and is in a position to handle orders at short notice and to react quickly to changing client requests.”