|Hybrid conveyor belts typically are constructed from plastic belting and stainless steel rods. These conveyor belts offer bakers the advantages of both steel and plastic belts, such as beam strength, easy maintenance and repair. Photo courtesy of Ashworth Bros. Inc.|
Conveying systems drive the baking industry. Whether propelling bakery foods through ovens, proofers or coolers, or transporting dough through makeup systems, these integral workhorses of the baking industry provide the power to ramp up production and automate baking processes. Unfortunately, many conveyor belt and system suppliers say that these key bakery components have been neglected due to reduced maintenance staff, downtime and pressures to increase capacity.
“We have seen a trend for the last three years in maintenance staff decline,” one conveyor engineering and technical service supplier says. “Bakers are outsourcing conveying maintenance to companies like ours, which opens up a new avenue of business for us, but usually causes the maintenance process to suffer. We can fix their problems, but we can’t help them prevent problems.”
Outsourcing conveyor maintenance and sanitation makes sense for high-volume bakers, and there are several conveying specialists in the industry that provide excellent routine conveyor maintenance and service. But what about non-routine service? When a belt has tracking difficulties, who fixes the problem before it becomes a major issue?
The decline in maintenance personnel has exposed many deficiencies in common preventive maintenance practices, which used to be standard 10 years ago. As a result, conveyor system and belt suppliers are manufacturing new systems that are maintenance friendly and withstand high speeds with little downtime.
Plastic vs. steel
The ongoing debate between plastic and steel conveyor belts continues to rage between leading belt suppliers. Unlike in years past, both sides generally agree on the same advantages, disadvantages and limitations of each belt style. “I think with the exception of baking applications, there has been a trend toward plastic belts, as these are marketed as easier to maintain and repair than steel belts,” says one manufacturer of steel and plastic belts.
And many manufacturers of steel belts agree with these points. “There are design advantages to plastic belts,” one steel belt manufacturer says, “but they don’t do anything that steel belts can’t do.”
Steel belts, once the standard of the baking industry, have faced extreme competition from plastic belts that run quieter, require less lubrication, are easier to fix and feature modular construction. These four benefits make plastic belts a savior for maintenance personnel.
However, plastic belts cost more than steel belts, a factor that continues to increase in significance as other operational costs skyrocket.
“Everyone wants to go toward plastic belts, but they want it at the prices of steel belts,” one belt supplier says. “In my opinion, it’s tough to justify the expense.”
One manufacturer has found the middle ground in the plastic vs. steel debate by manufacturing a hybrid belt made with plastic and stainless steel. Instead of plastic rods, these belts use stainless steel rods, which give the belts more beam strength. This allows the belts to carry heavy loads without sagging in the middle.
Maintaining and fixing hybrid belts is simpler than maintaining steel belts, the supplier says. “Using common hand tools, it is quite easy to remove the steel rods from the acetal links," notes the manufacturer of this belt. In standard steel belts, "cutting and welding of steel do not translate into less downtime. We see our belts as the next evolutionary step in conveyor belting after modular plastic, as our belts maintain the benefits of plastic belting while incorporating the strength characteristics of steel belts.”
Besides the debate between plastic and steel, one belt supplier also is pitting plastic belts against fabric belts in dough transport systems that require close transfers. The plastic belt has a small, 1/2-in. pitch and is used in bi-directional travel. In addition, the plastic belt has a unique non-stick surface designed to provide ideal release in high-moisture doughs, which significantly reduces the need to apply flour to the belt, the supplier says.
Oven conveying advances
For maintenance staff, oven conveyors often provide the biggest headaches. From tracking difficulties to conveyor breakdowns, oven maintenance is an arduous and time-consuming chore. Many conveying system companies have alleviated these concerns by building more durable and maintenance friendly systems.
One conveying system manufacturer has spent the last few years retrofitting tunnel ovens to replace friction-style belting with positive-drive systems. This company says that most friction-style belts have tracking difficulties, causing the belt to wander back and forth.
The retrofitting process takes about three days to complete. During this time, the company installs a new belt and drive system. “The downtime is reduced significantly and you don’t have to have someone always monitoring the belt and adjusting the rollers,” the manufacturer says.
“When you have a friction belt and start adjusting rollers, you losecontrol of the belt because you’re stretching one end of it.”
If a bakery cannot sacrifice three days of downtime, many conveying systems engineering companies offer services to align conveyor belts.
“We will do an evaluation to make sure everything is square,” the service provider says. “We shoot it with a laser transit just like surveying equipment.”
Another manufacturer of ovens and conveying systems manufactures ovens with 10-ft. radius curves, doubling the traditional 5-ft. radius curves. These 10-ft. radius curves reduce belt speed, which lessens general wear and tear. Lakeland, Fla.-based Butterkrust Bakery’s new bun oven has two offset oval tracks with a 10-ft. radius. Tom Sell, the company’s director of manufacturing, says the new oven significantly reduces maintenance costs compared to the company’s old 5-ft. radius oven.
The trend toward decreasing maintenance staffs in the baking industry shows no signs of slowing. Any effort, whether large or small, to reduce conveyor maintenance will make significant differences to high-volume bakers.