Tortilla Processing: Faster and More Efficient
June 1, 2010
by Shane Whitaker
During the past decade, tortillas have entrenched themselves into the diet of many Americans, as evidenced by the products’ rapid growth in sales and styles. Wraps made with flour tortillas appear on virtually every quick-service or fast-food restaurant menu, and tortilla chips can be found in pantries across the country. Tortillas, like sliced bread, are considered a staple food in many American households.
Manufacturers of tortilla processing equipment continue to improve their machines to be faster and more efficient. “As the tortilla market matures, processors are looking for savings in production efficiency because the growth is not as strong as it has been for the past 10 years,” said Bruce Campbell, vice-president, parts and service, AMF Bakery Systems, Richmond, VA. “Thus processing systems that save money in accuracy and speed, as well as maintenance and sanitation costs, are needed.”
Bigger, faster and more efficient are the qualities processors desire in new tortilla processing equipment, according to Kyle Armstrong, sales manager, J.C. Ford Co., La Habra, CA. “Presses that were pressing four tortillas at a time are now pressing 25 tortillas,” he said. “With corn tortillas, it used to be that two rows were being sheeted at a time. Now there are up to eight rows, and with our new oven, we will be able to achieve a 10-row system eventually.”
Tortilla processors want better yields with tighter specifications and higher speeds, according to Glenn Shelton, vice-president, Lawrence Equipment, South El Monte, CA. Equipment manufacturers have “to enable the producer to achieve tighter spec control at higher speeds with less labor,” he said.
AMF offers full system solutions for automating the flour tortilla makeup area from mixer to chunker to divider/rounder, resulting in labor savings and production efficiency, according to Mr. Campbell. Its equipment can produce tortillas ranging from 6 to 18 in. at speeds up to 2,000 doz per hour per line. “The new KX-T divider/rounder is the most accurate divider available, with a life of 20-plus years and extremely low maintenance costs — less than $5,000 per year,” he said.
Also, its equipment is flexible because processors often require shorter batch runs with greater product variety, Mr. Campbell added. “The KX-T divider/rounder can be changed from a 6-in. tortilla to a 14-in. tortilla with the touch of a button on the Allen-Bradley PanelView recipe management system,” he observed.
In addition, a new checkweigher system can automatically adjust the divider to stay within a 1-g accuracy. Its rounder bars are fully adjustable, and no changeover parts are required when adjusting tortilla sizes, according to Mr. Campbell.
After dough has been divided and rounded, a short resting period relieves dough tentions prior to the dough balls being sent to the press. Lawrence recently introduced a new Vac head for the Mega 52 and Legend 42 model presses. It allows processors to meet the goals of producing tortillas within tighter specifications with a simple solution to the age old problem of keeping the platens perfectly flat.
After pressing thousands of cycles and being heated and reheated over time, pressing platens distort. The larger the platen, the greater the distortion amount. This results in variation of both the diameter of tortillas within a cycle and irregularity in roundnes when comparing tortillas of the same diamter. Historically, producers have strategically placed strips of thin metal under approxiamte positions of the press head to compensate for the distortions.
Instead of this, Lawrence’s Vac head press employs Teflon-coated pressing skins that can be shimmed perfectly for each of the producer’s sizes in just a couple of minutes. The Vac head press is avaialable as an upgrade on both its Legend 42 and Mega 52 systems. It provides the producer with Teflon-coated pressing skins that retain the producer’s ideal shim pattern/program array that a producer makes. Using this system, processors can feather in the exact amount of shimming they need to make more consistent product because of the very thin special alloy aluminum sheets make this possible, according to Mr. Shelton.
The uniquely fabricated main upper press platen used in the Vac head design features vacuum assist to which the skin is secured, and the Teflon-coated skins are pre-indicated for precise location of shim by diameter and program array. “We are talking about ability to dial in shimming precisely,” Mr. Shelton said. “Once it is done, you don’t have to compromise on anything, and you can use a different pressing skin with different array that is tailored for your press and for your diameter. It only takes a couple of minutes to change a skin and optimize for 5-, 8-, 10- or 12-in. products. We can dial that in and repeat it each and every time.”
J.C. Ford’s latest continuous tortilla presses also feature devices for more easily shimming the platens. “We have a series of bolts that we use to deflect the plate in different areas,” Mr. Armstrong explained. “For example, let’s say you have a tortilla that is ¼ in. undersized in the front left corner. Now instead of taking out that whole assembly and sticking a shim stock under there, you can actually control it using a jacking bolt fastened to the top structure. The bolt uses the pressure between the two to push down the platen just slightly enough to create more pressure specifically in that area.”
Heat and Control, Hayward, CA, manufactures a variety of equipment for tortilla production, inspection and packaging. It supplies dry corn preparation systems, corn flour mixing systems, pre-sheeters, sheeters, toaster ovens, conditioning/cooling conveyors, metal detectors, checkweighers, X-ray inspection systems and tray sealers. For tortilla chips, tostadas and taco shells, the company also offers continuous fryers, seasoning applicators and a variety of conveyors, as well as bagging equipment.
For table tortillas, its systems can produce up to 7,500 doz per hour, and its chip systems’ production capacities range from 200 to 6,750 lbs of finished product per hour.
Heat and Control recently expanded its Compact Fryer range to include the 700 GS fryer. It decided to develop this new fryer so processors could make various products using the same equipment. “This economical continuous fryer can be used for tortilla chips, tostadas and many other snack and prepared foods,” said Caleb Reyes, regional sales manager, processing systems, Heat and Control. “Gas-fired or electrically heated, the 700 GS fryer is extremely simple to set up and operate and has 7 sq ft of frying area but takes very little floor space.”
Ovens that bake tortilla chips can operate at temperatures as high as 900°F, according to Mr. Armstrong, and because of this, J.C. Ford is working on a new oven that will recover heat from the oven to either be piped back into the oven or to heat water either for cooking corn or for other uses in the plant.
“We are going to use exhaust heat to pipe around a heat exchanger, then run water around it and into a storage tank,” he said. “When cooking corn, instead of pumping water in at 60°F, you can start with water at 120°F or even 90°F. A facility can reap huge savings by bringing in cooking water a few degrees warmer.”
Companies looking to increase capacities in many instances have started using larger equipment, which can present its own sets of challenges. “The larger the equipment, the harder it is to maintain consistency,” Mr. Armstrong said. Accordingly, the OEM implemented larger diameter rollers on its sheeters that reduce deflection across the rolls and result in more consistent weights, he noted.
Also, J.C. Ford offers automatic thickness control (ATC) on its sheeting lines for manufacturing tortilla chips. The patented ATC system uses lasers to scan the masa ribbon at the pinch point, and the system sends this information to a PLC that commands a servo motor to automatically adjust the gap between the two rollers, according to Mr. Armstrong. By using ATC, a facility most likely will be able to eliminate the person whose job is to collect a certain number of chips, weigh them and then adjust the roller gap on the sheeter based on whether the products were over or under their target weight, he said.
Both J.C. Ford and Lawrence offer vision inspection systems to monitor tortilla shape and size. J.C. Ford’s system rejects out-of-spec tortillas, and it also offers trending reports that operators can use to guide adjustments along the line, thus making more consistent product.
Lawrence also introduced a new vision system, Accuview III. It connects via Ethernet, uniting the line from divider through the counter/stacker. The inspection system collects data for each position on the press head and alerts the operator about what shim needs to be done per position to improve the quality of products.
Accuview inspects every single product that is made on a line. “While taking the place of one or two employees, it also saves the technician’s time who would normally do the shimming, makin the combination of the new Vac head with Accuview III nearly revolutionary,” Mr. Shelton stated.
Some Ishida X-ray inspection systems from Heat and Control can detect fill differences to let a manufacturer know if a tortilla is missing from a package, according to Mr. Reyes, who said it is like having a built-in checkweigher. “Ishida has also developed a dual weight range checkweigher that can inspect light and heavy packages,” he said.
The need for greater inspection efficiency and food safety led to development of the CEIA THS 21 metal detector and new models of Ishida X-ray inspection machines, according to Kevin Jesch, manager of inspection systems, Heat and Control. “The new CEIA MS21 series metal detector has been very successful in applications in the baking industry,” he said. “Its ability to compensate for product effect and for greater variability of product, including moisture and temperature variation, provide the best sensitivity for metal detection in the industry today.”
Tortilla products are ubiquitous in the American diet nowadays, thus the growth in the tortilla market over the past decade is finally slowing. However, manufacturers of tortilla processing equipment for flour and corn tortillas, as well as corn chips, continue to update their machines so that production can be faster and more efficient. ◾