MULTIHEAD WEIGHERS HAVE MADE A MAJOR CONTRIBUTION TO CONFECTIONERY AND SNACKS PACKAGING, AND CONTINUE TO INNOVATE AS PART OF FULLY-INTEGRATED PACKAGING LINES
by Torsten Giese, marketing manager, PR & exhibitions, Ishida Europe
The importance of accurate product weighing cannot be overstated.
Besides the legal requirement of producing packs at their declared weight, contents giveaway – effectively giving the consumer free product due to overfill – is wasteful, particularly in today’s highly-competitive markets.
Just as importantly, unreliable and inconsistent pack weights harm brand reputation.
Confectionery and snack products were some of the first to benefit from the introduction of multihead weighers in the 1980s. Many such products had previously been difficult to weigh to a predetermined amount.
The individual weight of some sweets and snacks can vary considerably, meaning that packs can quickly go from being underweight to overweight by the addition of just one or two more pieces.
The impact of accurate multihead weighing was immediate and significant. Product giveaway, which could be as much as 10 per cent using manual weighing on bench scales, was reduced to around one per cent.
Simultaneously, accurate filling meant packs could be designed smaller, reducing the cost of packaging, storage, and transport, all valuable sustainability benefits today.
On speed, even the earliest models were able to achieve about 55 packs per minute (ppm) for confectionery. Current models can weigh at up to 300 ppm for single products, and typically 80 ppm for six-mix applications (60 ppm for eight-mix).
Even more important to manufacturers is the increased productivity that accurate weighing can bring. For example, product previously wasted in overfill can now be packed into additional bags. Output can thus be increased without extra input.
Over the years, continuing developments and enhancements have enabled multihead weighers to deliver even faster speeds and greater accuracy. At the same time, many confectionery and snack lines have characteristics that can make them difficult to handle during weighing. This has led to features and application-specific multihead weighers that can deal with more-difficult products.
For instance, special contact surfaces have been developed to enable sticky items like jellies and gums to move freely through the weigher, and cushioning inserts and gentle-sloping feed and discharge chutes help to prevent fragile products from chipping and breaking.
Multihead machines have helped the introduction of mixed products where the weigher is split into sections to handle individual products at different target weights for discharge into one pack.
In particular, this allows an expensive or popular component to be controlled very tightly, with any potential overall pack deficits being ‘topped up’ during weighing by adjusting the weight of the less-expensive components. This ensures the pack receives identical weights and that the costly and popular ingredients are always represented in the mix in the same proportion (thus reducing customer complaints).
With the variety of different pack types available, such as bags, pots, and jars, special distribution/ filling systems are also supplied to ensure an accurate, consistent, and spillage-free interface with the weigher.
This shows how weighing equipment has today become part of an integrated solution, where different machines work together to provide a complete packaging answer.
For snacks applications, Ishida has developed its bespoke iTPS software, which supports integrated operation with multihead weighers, bagmakers, throat metal detectors, printers, sealtesters, and checkweighers to maximise line efficiencies.
Metal detectors, sealtesters, and checkweighers all provide valuable quality-control checks during packaging. Meanwhile, versatile X-ray systems now offer a much wider check for foreign bodies – with the ability to detect even tiny particles of materials that could conceivably contaminate products, including metal, glass, stone, rubber, and plastic.
Machines can also spot missing items and damaged product.
Looking to the future, speed and efficiency will continue to drive the development of new equipment. Ishida’s latest RV multihead weigher, for example, delivers the highest accuracy levels of any multihead weigher, whilst being some 15 per cent faster than its predecessor.
For snack products, our new Charge Transfer Control (CTC) system, available on the market-leading Atlas range of snack-food bagmakers, has increased their already-high speeds on potato crisps by a further 35 per cent – to a performance-topping 150 bags a minute – on a single machine.
New products will also continue to bring challenges.
Recently, we were able to cut produce giveaway by as much as 35 per cent at a South African snacks manufacturer, following its launch of novel pop crisps.
The company had found that, owing to the lightness of this new formulation, its existing weighing equipment was unable to cope – with too many overweight and underweight packs leading to a high amount of product waste.
In this way, new product development in confectionery and snacks will continue to influence the on-going advance of multihead weighers and associated equipment.