New granular weigher beats multi-head rivals for accuracy

Ishida Europe has launched a new version of its Cut-Gate Weigher targeted at more finely granulated dried food and beverage products that it claims is three times more accurate than multi-head rivals.

Torsten Giese from the UK-based packing and weighing firm said that the machine was well-suited to fine weighing of granular products within a 1/10mm to 1mm range.

He said: “If it’s a really difficult fine product, or if they [food firms] need really good accuracy because it’s a high value product, then the Cut-Gate is a really good solution.”

Examples he gave were coffee, tea and other drinks, as well as sugar, salt and couscous (even larger-sized pharmaceutical or chemical ingredients) which are non-humid and should not stick together.

Giese added: “If a granule is, say, 1/100mm then we may be able to do it, but we need to test the product. If the product is exposed to humidity in a factory, then it will cluster together and that will make it very hard to weigh accurately.”

New weigh hopper

Fine granular food products were often damaged by auger or volumetric cup fillers, Giese said, where the new Cut-Gate system has a newly designed weigh hopper to prevent damage, and only uses one, whereas multihead weighers often have several carrying different amounts of product.

Explaining how Ishida’s system worked, Giese said: “What we have is simply free-flowing [system using gravity].

So if something [a product] is on the top of the machine, we let through a certain amount into a hopper (with a load cell attached). So we’re letting through, say, 2/3 of the target weight initially (say 600g out of 1kg of washing powder).”

To weigh 1kg, Giese said, the Ishida system simply, “let the product flow through, by having a [servo powered] gate that opens maybe only 10 per cent, up to 1000g. We then close the gate. This happens reasonably quickly.

So what is does, basically, is rough weighing and then a fine weighing.”

Impressive accuracy

With a load cell underneath, the gate closed “so quickly and so exactly”, Giese added, with the machine typically able to process 25 weighments per minute of a typical drink product or soup ingredient with Ishida’s single-head variant of the machine.

Giese said the machine was able to weigh 1kg of washing powder to an accuracy of +/- 1.5g, he added, in comparison with +/- 5g for a typical multi-head weigher.

Explaining why Cut-Gate did not damage products in comparison with augur fillers, he added: “Often augur fillers use a screw, which moves the product forward at a certain speed and size. And that determines the amount of product that goes into the pack”

“They [the screws] turn through the product. So if you have a product like granular tea, if something turns through it, it will damage its values – the granular integrity.”

Geiss said the machine matched multi-head rivals for cost, and could be tailored to meet specific product, pack and line requirements.

For instance, it can be fitted with at least 10 heads. It joins an existing 14-strong standard Cut-Gate range.

Source: Ishida Europe