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Weighing up the Australian food industry

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Tecweigh provides food grade, stainless steel feeders for the industry that are highly accurate, dependable and hygienic, and are suitable for a range of applications.

Located in Carrum Downs in Victoria, an Australian dynamic weighing specialist has put more than 20 years of manufacturing expertise behind the design of bespoke in-motion weighing and metering products that are suitable for the food industry.

Supplying to Brisbane, Sydney, Melbourne and Perth, Tecweigh’s food-grade, stainless steel weigh belt feeders and volumetric auger feeders are manufactured using locally sourced components.

The weigh belt feeders offer top performance and easy calibration to ensure accuracy, dependability and food-grade hygiene, while the volumetric auger feeders’ internal agitation system encourages product flow.

Weigh Belt Feeder

Tecweigh’s business development manager, Barry Gamble, explains how the weigh belt feeder works for the food industry.

Barry Gamble, business development manager for Tecweigh, explains that the weigh belt feeder distributes the product on a belt to a weighing section, then removes the product from the belt.

“It’s about mixing the raw product, recipe mixing, or batching. It works on many products and ensures each product is given the correct ingredients in the right proportions,” he said.

There are certain elements that can be custom made to cater to the clients’ needs, such as the belt width, belt speed and the height and depth of the material bed.

“We custom engineer the product using the customer’s parameters of product bed depth, belt width, and belt speed to optimise and meet the flow required in either kilograms or tonnes per hour,” Gamble said. “It could have an Ethernet IP output to go into a PLC that can monitor the scale parameters in real time.”

High accuracy

The accuracy of the weigh belt feeder is +-0.5 per cent for a single idler weighing system, or +-0.25 per cent for a dual idler. Another factor Tecweigh has considered in their designs is how to contain the material on the belt for different applications.

“Another important factor is containment of material on the belt which can be by a wave edge belt, or if they want a larger bed depth, they can use stainless steel side rails,” Gamble said.

“We are talking to a customer who produce salads and because it is a much a lighter product than say potato, the product bed depth bed needs to be higher to achieve the same throughput. We use parameters around depth, belt width, and speed to achieve the optimum throughput.”

Maximum accessibility, minimal build-up

Another feature of the Tecweigh weigh belt feeder is it minimises the amount of material build-up. On its continuous loop belt in the production line, once divested of its material the belt travels underneath where an ultra-high molecular weight polyethylene (UHMWPE) belt scraper cleans it as it moves.

“The inlet and outlet chutes can be custom-made to fit the needs of the end user’s process,” Gamble said. “Sometimes a tank or hopper is installed above, the head of product sits there and as the belt moves along and drags the product out at the speed that’s required. After weighing, the product is dispensed off the end of the belt through a flanged discharge chute.”

The weigh belt feeders also include built-in calibration weights.

“Firstly, you zero a clean belt–any small deviations in the weight of the belt are absorbed in the zero tracking function of the WP20 Weight Processor,” he said. “A calibration cycle is initiated and the WP20 process guides you through adding the weights and advises you when to take them off. Then the process is complete.”

Volumetric Auger Feeder

feeders
The volumetric auger feeder features a poly flex hopper with massaging paddles, to prevent bridging.

While the weigh belt feeder can be used for any product, the volumetric auger feeder from Tecweigh is intended for more precise dosing of flowable or granular products, in smaller additions.

Gamble says the augers are available in sizes from 12mm to 152mm in diameter, and there are various feeder sizes capable of dispensing between one and 20,000 litres per hour.

“It’s a screw auger, where its speed and diameter will determine how many litres per hour it can move, as opposed to kilograms per hour,” he said. “It’s all about how dense the product is. It’s suited for a more accurate dosing of powders and granular products into food; the biggest application is salt, spices, and seasonings in the snack food industry.”

Toolless disassembly

The volumetric auger and feedtube assembly are easy to remove, using a single lever operation. If an operator tries to remove the auger and feedtube during operation, a safety sensor fitted to the mounting shuts down the drive motor.

Prevents bridging

Many feeders on the market have solid metal sides with the auger turning around at the bottom. This can lead to the product caking up and becoming stuck, which is known as bridging.

“In response to this, we have a poly flex hopper with massaging paddles, and they help the flex hopper stop bridging,” Gamble said. “The flowability of the product is key. The options are single drive, where one motor will drive the auger and the massaging paddles together.”

For difficult products, a dual drive option with two motors is available, in this case the auger and the massaging paddles are driven independently, Gamble said.

“For more accurate control, you would mount the feeder onto four load cells, so you can measure kilograms per hour instead of litres per hour,” he said. “Then using the feedback from the load cells to a PLC, you can adjust the speed of the paddles and auger independently to achieve the optimum dosing – this is called loss in weight.”

This means that the food producer can determine how much product is being dispensed and if the speed of the paddle or auger needs to be altered.

Level sensors can also be installed in the inlet hopper to identify when a refill is needed.

“When refilling the inlet hopper, the weight signal from the load cells is ignored by the PLC and the last remembered speeds of the auger and paddles are maintained during the refilling process,” Gamble said. “A second level sensor can be incorporated near the lid of the hopper to restart the feeding process when the hopper is full.”

For more information about Tecweigh’s range of food-grade feeders, visit www.tecweigh.com.au.

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