Conveyor Belting: A Bakery's Highway
September 01, 2009
by Shane Whitaker
Conveyors and conveyor belts play an important role in an automated bakery. They are essential to moving products from one processing area to the next. After ingredients have been mixed together, conveyor belts generally become the highways and byways on which the products transfer from one process to another and then to packaging without being handled by laborers.
Bakeries use a wide assortment of different belt types from fabric to plastic to steel to hybrids, and these can include open-mesh or band belts. There is belting for ovens and cooling, transferring and packaging. Belting manufacturers continue to improve the designs of their systems to increase throughputs; save costs by reducing labor, downtime and energy consumption; and assist with sanitation and maintenance. Bakers want long-lasting, economical belts, according to Michael Galvanauskas, business development manager, bakery, Habasit America, Suwanee, GA. Processors desire belts that feature modular construction that allows for fast installation and repairs, as well as trouble-free products with designs that withstand long production cycles, he said. With 70% open area for increased airflow, this belt uses include cooling, proofing, baking and reclaiming.
The latest introductions from Ashworth Bros., Inc., Winchester, VA, include the Omni-Pro stainless steel and Advantage plastic spiral belts, both engineered to maximize throughput and minimize lifecycle costs, according to Joe Lasecki, the company’s chief engineer. Omni-Pro, which is available in various pitches from ¾- up to 1½-in., features a patented link design and weld that increases strength and runs smoother to improve belt life and reduce system wear, he said.
Omni-Pro belts, which are used in spiral coolers, proofers and freezers, can be supplied as rod only or with a mesh overlay. “The zero-tension, 360° weld on the Omni-Pro increases strength and completely encloses the end of the rod to prevent product entrapment,” Mr. Lasecki noted. “The patented protrusion leg and coining process of the Omni-Pro link reduces wear and increases belt life.”
Spiral ovens are being used in other industries more often, and Mr. Lasecki predicted that soon these will be evaluated in the baking industry. “The reduced footprint compared with a baking oven that may be 300 ft long can save both energy and valuable floor space,” he said.
Wire Belt Co. of America’s latest conveyor belt innovation for the baking and snack industry is the Compact-Grid, which is designed with 70% open area for increased airflow, according to Jamie Card, marketing specialist for the Londonderry, NH-based company. “The belt’s unique grid pattern and small opening size are perfect for small products such as potato chips, tortilla chips, pretzels, etc.,” she said.
The belt is ideal for moving doughy products such as cookies that have just been baked and are still soft. “CompactGrid provides optimal cooling capabilities and offers enough support so that the product does not deform down into the belt during transfer,” Ms. Card said. “Products that are soft and doughy have a tendency to fall, or nose, into the pitch of widerspaced belting.”
For example, the soft edge of the cookie may fall into the wide space of a ladder-type belt and harden in that position, increasing the chance for product breakage and waste. CompactGrid is engineered for performance with 10 mm square openings, providing plenty of support for smaller products with no catch points.
CompactGrid also can be used in ovens and proofers as well as for reclaiming. “A potato chip manufacturer uses CompactGrid on an oil reclaimer on the exit of a fryer, allowing the excess oil to flow through and be recovered,” Ms. Card noted.
After changing from its existing flat wire belt to CompactGrid, one processor’s drainage capabilities improved significantly. The new belt’s thinner profile allowed the oil to flow though easily, eliminating the previous issues with the higher profile flat wire belt.
Additionally, the belt is a current prospect to replace balance-weave belts in ovens, according to Ms. card. “Our conveyor belts are generally better for oven applications versus balance-weave styles because they are more open, have smaller belt mass and are easier to clean,” she observed. “Our belts use much less material and have increased open area, allowing the customer to bake the product faster, saving energy costs on both the drive motor and burners and increasing the speed of production.
“Many processors are able to speed up the oven using a more open mesh, which, in turn, speeds up the entire line of production,” she continued. “The baking time in the oven generally determines the speed of a production line. If the oven speed can increase, so can every other conveyor, thus increasing production.”
The belt also handles raw dough and does a great job at releasing the product, according to Ms. Card. “One customer changed to CompactGrid conveyor belt after their raw dough became embedded in the previous belt, resulting in damaged and lost product, which also made the belt very difficult to clean,” she said.
Increased open area of the CompactGrid belt combined with its proven-to-be superior flowthrough characteristics will enable easier and more thorough cleaning and sanitation of the processor’s conveyor systems.
Intralox, Harahan, LA, recently partnered with Mol Industries to become the exclusive provider of ThermoDrive conveyor belts. Intralox ThermoDrive belting is a patented, homogeneous thermoplastic flat belt with a 100% closed surface. Like the company’s modular plastic belts, it is a positive (sprocket) driven, low-tension system especially suited for hygienic applications in food processing.
Ashworth’s CB5 Baking Band has been a baking oven industry standard since 1963, according to Mr. Lasecki. “The tight herringbone weave provides stable product support, even heating and allows cooking gases to be released uniformly, leaving a consistent and preferred pattern on the baked product,” he said. “To ensure true tracking and long belt life, the Ashworth CB5 Baking Band is precision woven with the tightest industry tolerances and inspected with 22 different quality checkpoints.”
The trend in the bake oven industry has moved toward wider and longer belts, according to Daniela Weiszhar, marketing director, Berndorf Belt Technology, Elgin, IL. While standard widths in the bake oven industry are 800, 1,000, 1,200, 1,250 and 1,500 mm, she said the company has even supplied belts, terminals and belt-tracking systems for a special oven in which the belt was 2,380 mm wide.
Berndorf recommends its CARBO 13 belt for the baking industry. “During the production of this belt, the steel goes through a complex heat treatment process to achieve the required tensile strength and surface composition,” Ms. Weiszhar said. “CARBO 13 with its dark black surface, good acceptance of radiant heat, high thermal conductivity and low thermal expansion is a reliable base for bakery products.”
The company also offers a wide range of carbon and stainless steel belts for other food applications depending on the process and product. Berndorf belts are designed to meet the high requirements of baking, cooling, deep freezing and transporting bakery and snack goods, according to Ms. Weiszhar. “Our belts are used in various applications because they can yield high-quality products at fluctuating operating temperatures and high load cycles,” she noted.
Berndorf introduced a belt tracking system for trouble-free operation, according to Ms. Weiszhar. “This tracking system can withstand variable conditions including pressure and temperature while protecting the belt from excessive stress,” she said.
Taking advantage of the strength of stainless steel rods, Ashworth’s Advantage plastic spiral belts are guaranteed not to sag and eliminate the need for a center rail, reducing installation and operating costs, according to Mr. Lasecki. Also, he noted that the belts have been tested and proven to have the greatest open area of all plastic spiral belts, increasing airflow for the shortest dwell times and providing unsurpassed cleaning characteristics.
“Advantage belts uses ‘double slotted’ links instead of the ‘slot/hole’ combination of competitors,” he said. “The double-slotted design provides a very open construction that is easy to clean. The Advantage rod locking system allows quick installation and repair using only a screwdriver.”
The Advantage family of belts include the 120 and 200 for spiral coolers, proofers and freezers, and these belts provide increased airflow, excellent product release, easy cleaning and quick no-weld repairs. Advantage RL75, suited for cooling baked products on straight, turn-curve and spiral conveyors, reduces downtime with a patented rod locking system, allowing fast and easy no-weld repairs, according to Mr. Lasecki.
Intralox offers a wide range of plastic modular belts for dough handling, pan handling, proofing, cooling, spiral freezing, general conveyance and packaging. “At Intralox, our mission is to work with all of our customers to provide the right solution to their most challenging conveyance needs that delivers maximum productivity and profitability to their operations,” said Don Osborne, bakery team leader. “We have extensive experience in developing specialized solutions tailored to the needs of many different bakery industry segments. With a deep understanding of bakery processes, we are able to invest in new materials and products to create solutions that satisfy the many specific needs and also allow for significant savings — from dough to packaging.”
Habasit offers plastic modular belts in pitch sizes ranging from 0.3 to 2.5 in. to accommodate a wide range of applications. Micropitch, its smallest pitch belt, is capable of extremely small transfers by using nosebars as small as 0.25-in. in diameter, while its largest pitch belt handles loads in excess of 6,800 lb per ft.
Habasit’s extensive range of radius belts in a wide range of styles are designed to meet the requirements of every application in the baking and snack industries. “The unique materials offered in the HabasitLINK and KVP product ranges can withstand temperatures from -100 to greater than 450°F,” said Steve Fesperman, director of marketing for plastic division, Habasit America. “In addition to the standard range of plastic modular belts, Habasit offers the most innovative belts specifically for spiral applications.”
Plastic modular belts are commonly used on cooling lines because of the large percentage of open area that promotes faster product cooling, as well as with packaging lines and pan and tray handling. “Plastic is an exceptional choice for these applications because its low coefficient of friction minimizes pan damage.” Mr. Fesperman said.
Habasit recently introduced a reinforced extruded thermoplastic belt known as Cleandrive that can be positively driven by sprockets. The completely smooth surface eliminates areas that can be difficult to clean on conventional plastic modular belts. The company also launched its HabaGUARD product line for fabric and plastic modular belts. These belts contain an antimicrobial additive on all cover coatings and all running-side impregnation materials that pro- vides additional insurance to help prevent the growth of microorganisms in food processing.
Habasit’s fabric belts for the baking industry are made on sophisticated belt manufacturing machines, according to Mr. Galvanauskas. “Our fabric belts are calendar coated, which allows superior ply adhesion and minimizes the chances of ply separation,” he said. “This means that white covers stay white and pin holes in the cover of the belt are eliminated. It also allows easy joining and no need for films and foils. Our advanced fabric design allows for flexibility to wrap around small pulleys, the ability to withstand the temperature and oil influences found in baking and snack plants and protects the intermediate strength member of the belt.”
For tight transfers, Ashworth offers the Cleatrac belt and sprocket system, which moves around the smallest nosebar diameters in the industry, down to 0.2 in., to accurately transfer small products and minimize product damage.
How easy a conveyor belt is to clean is one the biggest factors a company considers when purchasing. And because more companies are initiating sustainability initiatives, they are also looking at reducing water consumption during cleaning operations. “Our style of belting is easier to clean, resulting in less water consumption,” Ms. Card said. “Also our belts are one of the lightest types of stainless steel belts in the market. The lighter the belt, the less energy consumption is needed.”
Belting is a key component in making today’s processing operations work with limited labor, and belting manufacturers continue to respond to industry needs with new belts to help them move products more efficiently through processing and packaging.