Pictured above: The funnels through which mix components are fed to the segmented top of the weigher. Mixing on the weigher ensures that each bag of Studentenfutter has an accurate amount of each ingredient.  All parts handling raisins are corrugated and Teflon-coated to prevent sticking.

An Ishida multihead weigher capable of handling a variety of hard and sticky ingredients has enabled German snack food manufacturer Heinrich Brüning to cut giveaway of expensive ingredients to just 0.5%, and delivered a fast payback on investment.

Heinrich Brüning GmbH makes many tons of Studentenfutter each day at its Hamburg factory. This popular snack, so called because students nibble it while revising, has ingredients which differ greatly in size, form and hardness: raisins, cashews, Parana nuts, almonds, walnuts and hazelnuts. Previously these were pre-mixed and then packed into 200g bags on multihead weighers designed to handle single products.  

The differences in the properties of the ingredients made it almost impossible to obtain a homogenous and consistent mixture, and in order to ensure each bag contained a fair mix Brüning had to include excessive amounts of the more costly cashews and Parana nuts. This led to extensive and costly giveaway. 

Ishida, whose equipment has been in use at Brüning's Hamburg factory for decades, solved this packing challenge with 24-head, R-Series weighers supplied in a 6-mix configuration, so that all mixing could take place on-machine, resulting in a much higher level of accuracy. 

The detailed design of the weighers took into account the different properties of the ingredients. Those sections handling nuts have contact parts made from polished stainless steel, the only material that can resist the impact of hard nuts, day after day. Where raisins are handled, contact parts are ridged and Teflon-coated to prevent sticking. 

The solution also addressed the space constraints at Brüning's Hamburg factory. Limited floor space and headroom were major challenges. "Restrictions on our site mean we can only grow internally," says the Production Department's Dieter Behnke. The CCW-R has a particularly small footprint, while the problem of the 3.95 metre headroom was solved by confining all the conveyors and funnels feeding the multihead weighers to the floor above.

Major advantages of the Ishida solution include speed and reliability, which are vital to ensure Brüning meets the high demand for Studentenfutter. The new packing line operates for two shifts each day at a consistent speed of 70 bags/minute, and pre-programmed settings on the Ishida multiheads make it quick and easy to modify the proportions of ingredients, or even omit some altogether, according to customer specifications. 

"Performance-to-cost ratio is outstanding", comments Dieter Behnke on the Ishida CCW-R installation.  

Along with the significant reduction in giveaway, the elimination of pre-mixing has also halved the number of personnel needed.  As a result, the Ishida installation quickly paid for itself. 

Matthias Behrens of Quality Control says: "Our Studentenfutter now contains each ingredient in exactly pre-defined amounts. This has further reduced our already low complaint level". He adds that cleaning of the weigher is also "very easy and fast."