Fast-track to accurate checkweighing

A new checkweigher from A&D Australasia will allow smaller operators to upgrade their production line to cater for increasing demand. Isaac Leung writes.

With a new consumer focus on organic and fresh foods and exotic ingredients, supermarkets are increasingly turning to small-to-medium sized Australian food manufacturers for their products.

While these contracts are lucrative, they also increase the demands on the manufacturers’ processes, necessitating faster production while still maintaining accurate portioning.

Accurate weighing of products is critical: it ensures manufacturers are not giving away too much of their product, and at the same time, are not short-changing their customers, which can lead to loss of contracts and fines.

According to Tom Armstrong, managing director of A&D Australasia, many smaller players in the industry tend to start by having operators manually sort product into packaging, and using static scales to weigh units individually.

However, this labour-intensive process can be costly, and slow. The obvious next step when scaling up operations would be to transition to an automatic process line and checkweigher system.

Fast and accurate
Checkweighers weigh products that are moving on a conveyor belt at very high speeds. A&D’s latest checkweigher, to be launched at AUSPACK PLUS 2013, for example, can weigh up to 200 0.5kg products per minute at a 0.1g resolution.

But with the speed of the checkweighers also comes issues with noise and vibration. These can obscure the actual weight of the package.

“As the package goes across the checkweighers, all sorts of variables are fed back to the indicator: the belt moving, the shaking, wind et cetera,” Armstrong explained.

An alternative approach
While competing checkweighers on the market tend towards preventing these variables by engineering very rigid and expensive mechanical structures, and dampening the loadcell, A&D’s approach uses the Japanese company’s expertise in analogue to digital conversion and digital signal processing (DSP) to quickly and accurately filter out the variables.

“For the last ten years, A&D has focused on digital signal processing, which is essentially looking at the variables coming from something under test, monitoring and measuring and simulating scenarios based on that information,” Armstrong said.

Previously, this DSP capability was used for testing and simulating automotive engines in Japan, but its application to the checkweigher means the electronics within the unit can “see” the process in slow motion, successfully isolating the actual weight of the package in under one-third of a second, as it speeds through on a conveyor belt at 120m a minute.

The flat pack advantage
Armstrong says the relaxed mechanical requirements of the A&D checkweigher poses many advantages to food manufacturers.

With an entry level price, small-to-medium sized food manufacturers can quickly upgrade to an automated production line without a massive initial outlay, but Armstrong says the specifications of the product will appeal to larger manufacturers as well.

Delivery, installation and maintenance are also made easier and cheaper.

“With conventional, rigid checkweighers, they come in big crates, and expensive technicians are needed for installation,” Armstrong said. “Our technology allows A&D to deliver it flat-packed, to be assembled on-site.”

“It’s all about reducing costs to the customer. Rather than have to have specialists travel out, with a big crate, this checkweigher can go in the back of someone’s car, and one of our retail partners can go out and do the installation.”

According to A&D Australasia, its sister company A&D TechEng can also help during installation if integration of the checkweigher with a PLC/SCADA system is needed. A&D TechEng is an approved Siemens Solution Partner and Rockwell Recognised System Integrator.

The checkweigher is designed to require minimal maintenance, and can be serviced by local weighing service companies without requiring special service tools or equipment, making it cost effective to run in the long term.

Australia will be the first country to get the new A&D checkweigher, when it is launched at stand 200 at AUSPACK PLUS 2013.


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