Packaging Scotland


Brand reputation is an important part of the mix

Product consistency is vital to maintaining brand image.  Latest weighing technology can help in ensuring the right proportion of ingredients in every pack, as Ian Atkinson of Ishida Europe explains

CHANGING consumer tastes and fierce competition are just two factors that are driving new product development in the food sector, with manufacturers introducing new and exotic recipes to help achieve differentiation on crowded retail shelves.  Convenience is another important consideration with many end-users seeking pre-mixed and pre-prepared products.

For manufacturers this brings a number of challenges. It is vital that consumer expectations are met in each and every pack.  Recipe consistency is therefore an important part of customer satisfaction and brand reputation.

Equally important, the ability to mix ingredients in the correct ratios not only meets legal requirements, where percentages in the mix need to be stated and adhered to, it also allows the more expensive items to be effectively controlled so that profits are not over or under compromised.

However, all this has to be achieved while maintaining high speeds and efficiency on the packing line.

The continuing development and enhancements of multihead weighing technology has made a huge contribution to mixed products.   Today there are weighers with 16, 18, 20, 24, 28, and even 32 heads, mixing up to eight different products simultaneously for discharge into the same pack. Machines can even be linked together to handle a virtually limitless number of products within one line. There are numerous benefits of the mixed weighing approach.  One machine can effectively do the work of two or more, saving on costs and significantly reducing space and manpower requirements in the factory. Each section of the weigher is dedicated to a different product and these can be set precisely at different target weights, ensuring the right mix of items is included in each pack and that the more expensive items (for example higher value cashew nuts in a fruit and nut mix) are tightly controlled.

The multihead mixed weighing approach typically offers increases in speed, accuracy and efficiency compared to pre-mixing. Keeping products separate until they are packed can also help to minimise damage compared to more mechanical pre-mixing processes.  Mixed weighing technology continues to evolve, and faster processing technology and the very precise product transfer now available mean new levels of competitive advantage can be achieved. In addition, high head models can be configured to feed multiple lines. And with many production lines now having to handle a variety of different product types, these weighers can also be configured to handle a single product for discharge simultaneously in up to eight different packs – delivering speeds of up to 440 packs every minute.  It is also possible to combine smaller mixes and discharge these into multiple outlets.

When choosing a mix or multiple outlet machine solution, there are a number of factors to consider.  Clearly accuracy and efficiency are essential but these need to be taken into account alongside the required speed of the line.  It is very important that sufficient heads are allowed per item in the mix to ensure a stable combination can be achieved for weigh calculations each time.

At the same time, the overall speed of the weigher will be dependent on the section using the fewest number of heads – so the more heads available (combined with enhanced weighing technology), the faster the potential speed. The nature of the product also needs to be considered. This will influence the angles, shapes and materials used in contact parts design, which will be critical to ensure effective product transfer through the weigher. Similarly, a suitable interface with the bagmaker or distribution system is necessary so fast and efficient throughput can be maintained. The size of the hoppers will also be dependent on the piece size, bulk density and target weight of the products being handled.

Companies therefore need to carefully assess both current and future requirements and discuss these with their multihead weigher supplier to find a solution that combines the speed and accuracy of an efficient packing operation with the consistency of product that maintains brand image and reputation. Both of these will deliver where it counts most – on the bottom line.