Flowers Foods' big line that can
Feb. 1, 2015
by Laurie Gorton
At first glance, pans seem to glide at a quiet, steady pace along the new bread line at Flowers Baking Co. of Oxford, Inc., Oxford, PA. But take a closer look, and you’ll find output running at blazing speeds up to 185 loaves per minute. It takes a lot of sophisticated technology to make things look so serene. To achieve all this speed, productivity and efficiency — and simplicity — it takes “The Flowers Way.”
“This bakery is designed to use automation to make the job of consistently baking high-quality bread simpler and more cost effective,” said Robert Benton, senior vice-president and chief manufacturing officer, Flowers Foods, Thomasville, GA. “Sometimes, you need more technology to achieve greater simplicity in operating.”
Spending $31 million to expand and equip an existing bakery answered a big need for Flowers Foods: It filled a gap in production coverage for the company’s Northeast region. “The Oxford bread line ties to our Lepage operations north of here and the legacy Flowers plants to the south,” explained Dan Scott, president, Flowers Baking Co. of Oxford. Its service area stretches from Washington, DC, through the New York metropolitan area, a region with 34 million people.
“Oxford is a fantastic spot for a bakery,” Mr. Scott said. “It has exceptional access to population and infrastructure.”
The facility, an hour southwest of Philadelphia, already housed a sweet goods operation when Flowers Foods acquired Tasty Baking Co. in 2011. Mr. Scott has been in charge here since then and, with Vice-President of Sales Joe Alvarez, has been steadily building the presence of Nature’s Own, Flowers’ signature bread brand, in the region.
“This area is a relatively new market for Flowers,” Mr. Scott said, “but there is a lot of opportunity for us, not just with Nature’s Own, but with Wonder as well.”
Building while running
On May 1, 2013, Flowers Oxford shipped its first loaves, but 10 months earlier, the new bread line was just drawings on computer screens and equipment under construction. The first thing was to add approximately 90,000 sq ft to the existing building, creating a total of 262,000 sq ft under roof on a 42-acre site.
Ken Buxton, vice-president of project management, Flowers Foods, arrived on-site shortly before the Aug. 1, 2012, groundbreaking to manage the design-build project. “The big advantage was, of course, that the land and part of the building already existed,” he said. “We were able to use two of the existing building walls as part of the new construction.”
With electrical power, compressed air, water and sewage connections already in place, the team proceeded to other issues. They expertly fit the building expansion onto the available land, taking into consideration municipal requirements and environmental issues, including preservation of bog turtle habitat.
Because of the complicated overlap of state and local jurisdictions, Flowers brought in a consultant to help navigate the process. “The Oxford area has many stakeholders,” Mr. Scott said, “and they were all willing and eager to help us. The Keystone Opportunity Zone in which the bakery is located offers benefits that help reduce the opportunity costs of projects like ours.”
Before Tasty Baking joined the fold, Flowers looked at many possible bread bakery sites, stretching from Virginia through Pennsylvania. “We knew we had to have a bakery in this area,” Mr. Benton said. The opportunity at Oxford fit that need, but the bread line team faced a narrow time window in which to get the project done.
The chief factor? Weather. With the May 1 startup date in mind, the expansion had to be roofed in by Dec. 1. “Yes, it’s different than building in the Southeast or out West,” Mr. Benton said. “Complications brought on by the weather ‘window’ are very challenging and take additional planning. You have to factor in ground freeze, snow loads, larger ranges of ambient temperatures and numerous other engineering factors into design and actual building. Even though Oxford posed a learning curve for us and our long-time building contractor, Register Construction, all were more than up to the job.
“At Flowers, ‘testing the line’ means actually producing bread for the market,” he added, “and we were right on schedule.”
Another factor was the need to work around a “live” bakery: the snack cake, honeybun and donut lines running at Oxford, but this was almost a non-issue, according to Mr. Buxton. “The design of the existing building allowed hallways outside the production area that we were able to use for access to utilities, air and electric,” he said.
The building configuration, however, required that the in-floor basket stack conveyor run through the cake department’s packaging area to reach the shipping dock. “We carefully measured from the existing side and built up to the wall on the new expansion,” Mr. Buxton explained. “We then installed a construction wall in the existing building before we cut through the wall to connect the two sides.” A permanent rack bridge across the in-floor chain allows fork lifts to carry products and supplies across the chain conveyor without interrupting its flow.
While putting in the new bread line, the cake side had to run at full tilt. “During this time, we had an exit from the market of a major competitor [Hostess],” Mr. Scott said. “We added hours on lines to meet demand. The cake team was able to absorb that extra capacity and meet market demand. It was an exciting time!”
And the bread line ramped up fast. It ran two shifts for only a month or two. “We got to three shifts very quickly,” Mr. Benton noted.
Automating for simplicity
Oxford’s bread line embodies Flowers’ strategy of applying knowledge gained from previous installations, and it sets the stage for future improvements. Automation is deftly employed to simplify how the line runs, especially at the hand-off points between unit operations. Computer-based controls enable machines to record and report their conditions automatically to downstream stations. Provisions have been put into the design so it will seamlessly tie into the current enterprise resource planning (ERP) system in the future. Platform work was performed by Higgins Electric in the mixing and batching areas.
“You automate by addressing the hand-off points,” Mr. Benton explained. “For example, moving the dough from the mixer to the bread divider is one of many hand-offs. By engineering these hand-offs to require little, if any, direct operator involvement, you simplify the process.”
This approach to automation transforms the sequencing, interlocks and myriad checkpoints common to breadmaking by removing manual and mechanical factors in favor of servo-controlled and digitally sequenced methods. At Flowers, it helps bakery engineers re-examine, re-work and re-adopt preferred methods from the past and take them into the future.
A good example is the AMF Bakery Systems Servotech divider, one of the firsts in technology chosen for Oxford. Volumetric ram-and-shear dividing has long been favored by bread bakers. The new divider’s electronic linear actuators replace cams, bushings, levers and grease points, thus reducing maintenance and extending machine life and accuracy.
Capable of running 30 strokes per minute, this divider keeps pace with, and can actually exceed, the speed of competing technologies. The company added a checkweigher that sends data to the divider to automatically adjust the weight up or down to keep dough pieces consistent. The company actually started development work with AMF Bakery Systems on the divider in its Denton, TX, plant four years ago.
Counting the firsts
The Oxford bread line reflects the collaborative work Flowers engineers do with their vendors, and for this bakery, those efforts yielded several improvements in technology — and firsts for the company. In addition to the servo-controlled divider, the bread line employs the company’s first AMF/BakeTech combination conveyorized proofer and oven, complete with steam in the oven; its first AMF/BakeTech MaxiSaver enclosed bread cooler; its first Workhorse Automation on-demand gantry-style pan and lid management system; and its first use of Formost Fuji new-generation overwrappers.
Like the new bakeries created by Flowers at Denton; Newton, NC; and Bardstown, KY, the equipment layout features the company’s signature straight-line design and 12-ft aisle enabling quick access to every system on the line.
Oxford continues the company’s practice of wide-way conveying, a technique that sets strapped pans on conveyors to travel with long edges leading. At six loaves per pan, this method helps the line run larger volumes at slower speed and with fewer linear feet of conveyor. It minimizes use of T-transfers in favor of wider, more stable, quieter turns. Product flow “goes narrow,” as Mr. Benton noted, only after the loaves leave the cooler.
Oven and proofer exhaust stacks connect to a CSM catalytic oxidizer, part of a comprehensive heat recovery system from Air Management Technologies that captures BTUs from oven exhaust to heat water and the glycol that maintains proofer and bread cooler conditions. Giant overhead fans, a new technique, address temperature and air circulation within the production area and avoid the heavy cost upcharge for heating makeup air during colder times of the year.
“Before we begin a project, we always construct a timeline with all the vendors involved,” Mr. Buxton explained. “This gives us and them a visible sequence of construction. All the vendors were very good at working together so that all the equipment and controls meshed together without conflicts.”
The lead vendor for Oxford was AMF Bakery Systems and its BakeTech group. Higgins Electric worked with Shaffer, a Bundy Baking Solution, to implement an integrated batching and mixing program.
“At Flowers, we have a lot of experience starting up new lines and new plants,” Mr. Benton noted. “We spend a significant amount of development time with the vendors, and we do our own installation work with millwrights. We continually look at new technology, and we invest the time to learn it.
“With our process, before we hit the green button, we have a good idea of what will happen,” he added.
Revving the engine
Like previous new Flowers bakeries, the bread line operates with technician labor. “To take out manual work, you have to add automation,” Mr. Benton said. “The heavy-lifting jobs are pretty much gone.” That even extends to maintenance. “The laptop computer is now a required tool along with the tool belt,” he added.
While the cake and bread sides operate separately, they join up in the shipping area. Cake production is managed by Sam Mullin, director of manufacturing, cake, and the bread line by Brian Barton, director of manufacturing, bread, with oversight by Dave Mitchell, vice-president of operations. “From a management point of view, we are one bakery,” Mr. Scott said. “We operate with the same philosophy on both and are all on the same page. Coordination of operations is critically important.”
The facility’s team includes Keith Palmer, chief engineer; Stacy Kerr, sanitation; and Eric Maholmes, human resources. It employs a total of 228 people, with outsourced labor (production helpers, sanitation and shipping) numbering 102.
Bread production starts with integrated computer batching and mixing. Flour drawn from the Pfening bulk flour silos is staged into a pair of Great Western pneumatic sifters that feed the use hoppers in the mixing area. Sugar is also supplied by Pfening equipment, with flour and sugar tied into the minor ingredient system from the same vendor. The bakery uses supersacks for “major minors” (salt and gluten). Liquid ingredients such as honey enter the system pumped from bulk liquid totes, while yeast reaches the mixers from a cream yeast system. A bag-dump station manages smaller ingredients.
“The only hand-adds are the tablets,” Mr. Mitchell said. “And we’re planning a bulk sugar system with rail delivery for it and flour.”
Three Shaffer horizontal mixers are installed in straight-line fashion adjacent to the AMF automated fermentation room. Following sponge-and-dough protocols, the bakery prepares products using a No. 28 mixer for sponges. It outputs those into mobile troughs that automatically travel though the fermentation room. Picked up by a hoist and dumped into one of two No. 32 mixers, batches receive the rest of their ingredients, and the tilt-bowl mixer kicks out the final dough into the hopper of an AMF chunker.
The chunker’s large, bottom-mounted rotary blade assembly gently releases sectioned portions into a vertical conveyor that lifts the chunks to an overhead line feeding the divider. The whole chunker assembly — dough hopper, rotary blade and vertical conveyor — is mounted on rails to shift quickly between the two final mixers.
The Servotech divider portions seven dough pieces at once, releasing them to cross the weighbelt of the checkweigher in single file. They reach an AMF conical rounder that seals the cut surfaces. The speed of the line requires three AMF crossgrain moulders, so the system routes rounded dough balls through a horizontal switch to divert them into three lanes to rest before they reach the moulders.
Because variety bread doughs are considerably stickier than white bread doughs, dusting flour is required at several points in the dividing, rounding and moulding process. Flowers selected a W.D. Laramore vacuum flour reclaim system to manage flour dust. The vendor installed its prototype machine at Oxford, a system robust enough to meet California air standards, according to Mr. Benton. The design eliminates filter bags and directs reclaimed flour into feed hoppers along the line.
Conveying the change
Two decisions helped create the remarkably quiet environment within the bread operation. The first is a gantry-design pan management system, and the second is maximized use of plastic conveyors throughout the entire pan system. These choices, combined with wide-way travel, also help lengthen pan and glaze life.
“The Oxford bread line reflects a major change in how we manage pans and lids,” Mr. Benton said. When equipping Bardstown, the company wanted to make pan handling more automatic, so it installed a Fanuc robot system for handling and storing pan lids. For Oxford, it upped the ante and went to a Workhorse Automation gantry-style system for lids and pans.
The on-demand system that handles up to six pans at once proved to be reliable, gentle and quiet, compared with conventional stacker/unstacker units that run one pan at a time. The bakery’s 6-strap pans can weigh 40 lb each. Mr. Mitchell noted that the bread line uses four pan sets: 16-oz, 20-oz, 24-oz and so-called “wide” pans for preparation of overwrapped ovals.
The three gantry robots pick up multiple pans or lids at once, reducing the number of machine movements. Integrated with the robots, an automated storage and retrieval system (ASRS) continually moves pans to and from a single-level storage area according to product variety and line demand. Because the pans are stacked in layers vs. single stacks, the configuration is more stable, according to Mr. Benton. A Rexfab stand-alone pan inverter cleaner turns over and cleans pans just before entering makeup where they encounter Mallet pan oilers before reaching the moulder’s panning stations.
Between the robotic pan system and the Conveying Systems plastic conveyors handling dough, dough balls and delivery baskets, the plant’s ambient noise level remains relatively low. Stewart Systems supplied the pan and lid return conveyors, slicer feed and cooler feed conveyors, which also use plastic belting.
This bakery houses the company’s first completely integrated conveyorized proofer and oven system for bread. “We’ve used conveyorized ovens for breads in our bakeries before, but this is the first time we purchased it as an integrated system,” Mr. Benton noted. Although most of the bread made on this line goes out under the Nature’s Own brand, the technology is flexible enough to accommodate ovals, Flowers’ term for overwrapped loaves in 12-grain and other varieties.
The continuous conveyor proofer employs 2,642 ft of active travel, accommodating a 60-minute proof for 20-oz open-top bread at 185 loaves per minute. It uses heat reclaimed from the oven exhaust, with auxiliary heat capacity available. This style and size of bread bakes in 22 minutes in the continuous conveyor oven with its 917 ft of active travel. Both feature a spiral-in-spiral design that ensures even heat exposure for all loaves.
A steam tunnel at the oven entrance is turned on according to product need. Both the proofer and oven feature low entry / low exit configuration, making it easy to visually inspect products and to service the systems. “From a control standpoint, the proofer and oven are one system,” Mr. Benton said.
A Burford splitter-seeder system is placed between the proofer and oven.
Wide-way travel is maintained as the proofer and oven hand off pans, transferring them from individual grid carriers to conveyors. The same orientation is kept as pans pass through the Stewart Systems depanner-delidder. “You see this kind of depanner orientation in Europe, but it is not common in the US,” Mr. Benton noted.
Sensors inspect the empty bread pans before they return to the makeup area. If a loaf sticks in a pan or the sensors detect other debris, that pan is shunted aside and taken out of service.
Still grouped together in sixes, the hot loaves proceed to the enclosed heat-and-humidity-controlled bread cooler. The spiral-in-spiral system can move two hundred 20-oz loaves per minute along its 2,464 ft of active travel in 55 minutes. The bread cooler features a 4-in.-thick stainless steel enclosure and is Flowers’ answer to delivering bread to the wrappers in uniform, consistent condition 365 days per year regardless of ambient temperature inside or outside the bakery.
“Controlling the cooling process results in better quality consistency,” Mr. Benton said. “We knew that the Northeastern climate would have a wider range of temperature changes. In the Southeast, ambient temperature varies between 60 and 95°F; here, it’s 0 to 100°F.”
Flexing the line
Leaving the bread cooler, loaves encounter the bakery’s first right-angle turn. Loaves now travel one-by-one into packaging operations, passing through a Fortress Technology metal detector. The integrated system uses horizontal switches to feed four bagging lines, each consisting of an AMF bread slicer ahead of an AMF bagger. A longer-than-usual flighted conveyor mounted on wheels connects slicer to bagger. When running oval loaves, these conveyors are pulled out and replaced with three Formost Fuji overwrappers, also mounted on casters, that move into the designated position. Flowers engineers worked with the equipment vendor on a new wrapper design to enable this flexibility. “Putting the overwrappers in-line with the rest of the packaging equipment minimizes handling of the product and allows a much higher rate of speed and less scrap,” Mr. Benton observed.
The overwrapper sends packaged loaves along to the bread bagger, and they are sealed by a Burford twist tyer and individually dated by a Markem coder, just like all other bread items packaged here.
Bagged bread loaves enter AMF Versa-loaders at each wrapping station. These robotic pattern formers are used in a number of Flowers plants to load delivery baskets. The company standardized on basket size some years ago. Each delivery basket waiting to be loaded is first run through an AMF washing system: an unstacker, a trash dump unit and a basket washer.
The pattern former arranges loaves according to variety and size and inserts the grouped packages into the waiting basket. The system hands the filled basket off to the AMF bottom-up basket stacker, which cycles trays up until reaching the correct number of baskets.
The whole stack moves out onto the Cannon Machinery in-floor conveyor. Because of plant layout, the conveyor runs through the back of the cake room to the shared dock on the building’s other side.
All products — cake and bread — leave the bakery on trailers driven to Flowers’ warehouses. “These are located where best to serve our various markets,” Mr. Scott noted. The warehouses arrange the orders and, generally, independent distributors sell Oxford’s products to customers ranging from small retail grocers to large supermarkets, club stores, convenience stores and the full range of foodservice operations.
The Oxford bread line has a clean, straight layout and acres of shiny stainless steel housings, but its true beauty lies within. A look “under the hood” at this bread line reveals the automation that simplifies operations and the technologies that support everyday high quality and consistency. It’s a big, efficient line with the productivity to make it the production lynchpin in Flowers’ Northeast strategy.