With advances in technology, bakers have greater conveying options ranging from conventional friction systems to positive-driven alternatives. Bryan Hobbs, sales and service manager, Ashworth Bros said eliminating belt tension, which can cause belt stretching, breakage and other headaches began decades ago. Ashworth Bros. first patented its Lotension spiral system in 1967.
“Friction is a proven technology that goes back more than 50 years,” Mr. Hobbs noted. “As a result, there’s an extensive knowledge base that comes with it.”
With a Lotension spiral system, Jonathan Lasecki, Ashworth’s chief engineer, explained, the tension peaks at a calculated level — usually at the second or third tier — then remains relatively constant as the height of the spiral increases upwards of 20, 30 or more tiers. Going vertically minimizes floor space.
Positive-driven Intralox belting offers an alternative to conventional tensioned conveyor belts, noted David Bogle, global R&D director, spiral platform.
“Friction-driven belts can work fine when environmental conditions are very consistent,” he said. “In particular, friction and loads need to remain constant. Positive-driven belts, on the other hand, do not need constant conditions to work properly. Intralox provides only low return-side tension, positive-drive belts, meaning that for half its cycle the belt is under little to no tension and only becomes tensioned as a function of moving the product load. This configuration leads to much longer belt life and low wear on other conveyor components.”
Mr. Lasecki pointed out that positive-driven belts engage the cage drive bars. This reduces belt tension in the overall system and provides longer belt life. Additionally, oily baked foods don’t affect Ashworth’s PosiDrive belts. In fact, he said, oil and grease might enhance performance by providing lubrication to the positive-drive system.
Positive-driven systems provide several other advantages such as keeping dinner rolls or larger pies regimented as they leave the oven and travel through the cooling system before they enter the packaging area.
“As these products discharge from the spiral, you want to make sure they come out in the same regimented orientation as they entered the system,” Mr. Hobbs observed. “You no longer have to dedicate costly resources to reposition the product. Now those resources can be used elsewhere in the facility.”
David Bogle, global R.&D. director, Intralox, suggested that positive-driven belts can reduce maintenance by eliminating belt-tracking issues, repairing frayed edges and constant re-tensioning of belts.
“There are a few processes where flat belts are still required,” he said. “The plants have to keep up with the maintenance in those areas to make sure those belts run properly.”
This article is an excerpt from the April 2019 issue of Baking & Snack. To read the entire feature on conveyors, click here.