As they say in London, mind the gap.
To streamline sanitation and reduce waste, bakeries should focus on transfer points from one belt to another or from one conveyor to another piece of equipment.
Specifically, keep a close eye on the space between the two conveyors.
“As a rule of thumb, the transfer gap must be less than one half the width of the product being transferred,” said Bob Harrington, vice president of sales and marketing, Capway Automation. “If the gap between the two is greater than one half the product size, you will exceed the tipping point of the product. It will tend to nosedive into the next conveyor or piece of equipment and bounce up creating a rough transfer point that can lead to product rollover, loss of orientation and product skewing.”
Normally, , product orientation is determined at the beginning of the lines where baked goods must be evenly placed prior to any further processing, noted Rick Milner, product line support leader, Wire Belt Co. of America.
Closely observe the speed of any turn conveyors.
“If the speeds of the turns are too aggressive, the products will slide to the outer edge of the belt, which will cause issues further down the line,” he explained. “The transfer points can be critical depending on the size of the products. If the products are smaller than the transfer diameters, they can become wedged between the two conveyors, causing unnecessary waste. A simple dead plate or a live roller can solve some of these issues.”
Bernardo Zermeno, customer development director, Rexfab suggested rough transfer points can have many root causes, but the most common one is poor alignment.
“In some cases, the transfer rollers used in older technology are just not designed for the product being made on today’s production lines,” he said. “Tight transfers are a game-changer in these applications.”
During turns or transfers, certain belts may swing or flair out as they travel along the conveyor, explained Jonathan Lasecki, director of engineering, Ashworth Bros. Inc.
Moreover, watch for centrifugal forces that may cause the belt to extend as it goes around the transfer and increase belt vibration.
Check to make sure that the chordal action, which is the result of the belt transitioning from a flat state to being wrapped around a sprocket, remains flat and smooth to minimize vibration and movement of the product. Additionally, minimize the support openings of the belt that can damage products.
“Look at the whole picture of your production line, and not only the processing part of it,” Mr. Lasecki said.
With ovens, steel conveyor belts act as a window into the performance of the entire system, noted Craig Bartsch, global sales and marketing manager, belts, IPCO USA. If side-wandering occurs, for instance, the belt could come into contact with the oven’s structure or another rigid object, resulting in metal burrs. Wavy edges could be another indication of side-wandering or uneven oven temperature. It can also indicate uneven pressure from the belt cleaner or scraper or a belt scraper that is wider than the belt itself.
“We look for deformations in the belt, which could suggest problems with drums, supports or other parts coming into contact with the belt,” Mr. Bartsch said.
Fixing the issue often includes cleaning the drums, cleaning or replacing belt supports and checking scrapers, rollers and belt tensioning. Make sure to examine the underside of the belt since any scratches could indicate worn or damaged belt supports or safety scrapers.
“The condition of a belt gives us an insight into how an entire system is performing,” Mr. Bartsch said. “It’s almost always the case that belt condition is the symptom of a problem, not the cause.”
Meanwhile, Eaglestone provides a Tight Transfer Conveyor that’s designed for transferring small products from one conveyor to another conveyor or equipment without disrupting their orientation.
Joe Gongaware, sales engineer, Eaglestone, said the conveyor comes with solid one-piece stainless steel side rails for added rigidity and a fully welded design for reduced bacteria buildup for federal sanitation standards in food processing and packaging.
Doug Groebe, sales engineer for Eaglestone, added that angled roller belting can provide product justification for more consistent product orientation while the Constant Turn Fabric Belt Conveyor keeps products moving at a sustained rate around tight curves. Moreover, its Accu-Track belt drive system keeps the fabric belt in place while the tight nose bar transfer assists with keeping cookies, bars and other smaller products aligned.
Some product orientation issues can be simply resolved using lane guides or flighted conveyors to center pizza crusts moving into a topping machine.
“You can adjust the timing of the belt so you can place the products where and when you want them to be so they’re evenly spaced out by the flights every 14 or 16 inches, or whatever is required for the product or the speed of the line,” said Tom Trost, sales manager, Quantum Technical Services. “It keeps operators from guessing or randomly placing product going into a line.”
With raw dough or hard-to-handle small products, he added, using outfeeds such as roller or poly cord transfer sections can ensure small dough pieces don’t drop through any gaps.
“It can also keep seasonings from bagels or toppings from pizzas from falling down in between the conveyor or to the bottom of an oven with conveyors, which can create a potential fire hazard,” Mr. Trost said.
Jeremy Shall, bakery/snack North America team leader, Intralox recommended using tight transfer micro-pitch belts, zero tangent radius conveyors and technologies such as Intralox Side Drive to minimize or eliminate transfers and solve product orientation issues.
“Mistracking or misorientation usually happens when the conveyor belt system is set up at high tension,” he added. “On a spiral system, for example, if the inner drum is running faster than the outside drum, it easily causes the product to lose its orientation. The Intralox DirectDrive System spirals eliminate product orientation issues due to overdrive.”
This article is an excerpt from the March 2023 issue of Baking & Snack. To read the entire feature on Conveyors, click here.