Position: This page describes the an automated weigh batching system for spice ingredients batching.A food processing company automates a spice-batching process to improve quality control and production rates.
JTM Food Group, Harrison, Ohio, is a specialty food processor that produces various prepared-meat products, kettle-cooked products, and bakedgoods for the food service industry, the military, schools, andretail consumers. Many recipes include a spice mixture that gives a product its unique flavor. In the past, operatorsmanually scooped the various spices into a batch bucket positioned on a scale, individually weighing each ingredient. However, over the years as customer demand increased,manually scooping andweighing the spiceswas taking too much time and causing a bottleneck in the production process. The company needed to find a way to improve its spice weighing and batching.
Manual spice-batching process causes problems
The plant operates 16 hours a day, 5 days aweek, and produces three separate food product lines:The preparedmeat operation produces preformed burgers,meatballs, sausage links, and other fully cooked meat products; the kettle-cooking operation makes sloppy joe mixes, taco fillings, soups and sauces, and other flowable products; and the bakery operation produces hoagie rolls, Kaiser buns, and other baked goods that are sold in area stores and used for making the company’s sandwich products.
To prepare a spice mixture for a prepared-meat or kettle-cooked product, an operator printed out the mixture’s recipe, then brought the first spice bag tothe scale andhand-scoopedthe spice from the bag into the bucket until the proper weightwas achieved.The operator then gathered the second spice and hand-scooped the proper amount from the bag into the bucket. The operator repeated this process for each of the recipe’s spices and other minor ingredients.
To speed up the batching process, sometimes several operators worked together gathering and handadding the various ingredients.
This process had several problems: “It was too easy for an operator tomisread the scale or grab thewrong spice bag,” says JoeMaas, JTMFood’s operations
vice president. “And if they put too much of an ingredient or thewrong ingredient into the bucket, they’d have to throw out the batch and start over, which led to excessive product loss. Also,manually batching the spices limited production, because we couldn’t make aproduct if its spicebatchwasn’t ready. In addition, the process required a lot of labor and time, taking a good twelve to fourteen hours every work daytomake all thebatches.”
The automated weigh batching system can make a spice batch with up to 24 different ingredients in less than 8 minutes.
As the company’s business grew and production requirements increased, the problems with the manual spicebatching process became more noticeable. According toMaas, to keep pacewith customer demand the company needed to find a way to eliminate the production bottleneck.
Workingwith a familiar system supplier
In2004, the company had worked with a local weighing-and-batching system supplier to automate the bakery operation’s micro ingredient batching process. After installing the custom designed system, the company saw immediate improvement in the batching process efficiency and accuracy.
So in early 2008, the company decided to work with the same supplier to design an automated weigh batching system for the spices and other minor ingredients. “The supplier was my first and only call because the bakery operation’s system works so well, and we wanted an automated system similar to that one,” saysMaas. “However, for thespice-batching process,we needed a much more complicated system that could handle twenty-four different ingredients, produce multiple recipes simultaneously,and makeupto one-hundred-pound batches.”
The weigh batching system
The custom-designed automated gain-in-weight weigh batching system consists of 25 32-gallon batch buckets, 24 28-cubic-foot ingredient dispensers, 24 screw feeders with helix screws, one infeed belt conveyor, four weigh belt conveyors, one outfeed belt conveyor with a checkweigh station, and one PLC controller that controls the entire system’s operation. The batch buckets and ingredient dispensers are constructed of polyethylene and approved for use in USDA, FDA, and 3-ADairy applications.
Astainless steel, variable-speed screw feeder installedat eachdispenser’s bottom discharge bulk-and-dribble-feeds the ingredient. The feedrate is determined by the ingredient in the dispenser, with a maximum rate of 70 ft3/h. Each feeder’s screwlength is determined by a dispenser’s distance from the batch bucket’s fillingposition, whichranges from18to54inches.
The 30-inch-wide infeed belt conveyor, weigh belt conveyors, and outfeed belt conveyor are constructed of stainless steel and approved for foodgrade applications. The infeed conveyor, which can hold up to nine empty batch buckets, is more than 20 feet long,while each weigh belt conveyor is about 10 feet long. A gain-in-weight scale mounted on load cells is installed at the center of each weigh belt conveyor, forming the weigh station where a batch bucket sits during filling.
The system’s PLC controller has a flat panel touch screen that allows an operator to easily call up the various spice-batch recipes, monitor the system’s components, andmanage inventory.
For quality control, the PLC sounds an alarmif an ingredient being filledintobatchbucket fallsoutside the system’s±0.02-pound accuracy range.
The PLC also generates a tag that gives the lot number of each individual ingredient used in a recipe, allowing the company to track lot numbers from the ingredient manufacturer all the way into the finished product to provide complete quality control.
In summer 2008, the supplier—Ingredient Masters, Cincinnati—installed the system in the company’s ingredients room. A custom-engineered structural steel frame supports the system’s components and creates two 12-dispenser parallel rows with about 50 inches of space between them. The four weighbelt conveyors form a straight line between the two dispenser rows about 40 inches below the dispensers’bottoms. Eachweighbelt conveyor runs the length of three dispensers, separating the dispenser rows into four batching zones, each consisting of a weighbelt conveyor with three dispensers on each side of it. Theweighbelt conveyors move the batch buckets through the corridor between the dispenser rows, and the six screw feeders in each batching zone extend from the dispensers’ bottoms to feed ingredients into the batch bucket on the weigh station.
To help maintain a clean ingredients room, the supplier mounted the weigh belt conveyors on pneumatic rams that can raise the conveyors about 9 inches so operators can easily sweep and clean under them.
A walkway platform installed about 60 inches above the conveyors allows operators easy access to the dispensers for refilling ingredients. An electric-powered mobile cart that holds a pallet and runs the length of the walkway allows a pallet with multiple ingredients stacked on it to be forklifted up and easily moved to the appropriate dispenser.
To help maintain a clean ingredients room, the supplier mounted the weighbelt conveyors on pneumatic rams that can raise the conveyors about 9 inches so operators can easily sweep and clean under them. Also, a dust collection port ismounted above each weigh station near the screw feeders’discharges to collect any dust generated during the batching process.And a dust collection port inside each dispenser removes dust generated when refilling a dispenser.
Automating the spice-batching process
To make a spice batch using the new automated weigh batching system, an operator loads the infeed conveyor with empty batch buckets, then accesses the PLC, calls up one or more spice recipes that need to be batched, and pushes the start button.
The infeed conveyor then moves an empty batch bucket onto the first weigh belt conveyor,which moves the bucket to its weigh station. Once the bucket is in position, the PLC activates the screw feeders one at a time to feed the required spices into the bucket. After the first weigh station’s spices have filled into the bucket, the weigh belt conveyor moves the bucket to the next weigh belt conveyor,which positions the bucket on its weigh station.
At the same time, thePLCcalls up the second recipe in the queue (which may be the same as the first recipe or a different one), and a second batch bucket moves into the system and is positioned on the first weigh station.
The PLC activates the required screw feeders in each batching zone to fill the necessary spices into the buckets.
When both buckets have been filled, the weigh belt conveyors advance each bucket to the next weigh station, and the process continues for each recipe in the queue, with the buckets advancing through the system like a train, stopping at each weigh station to receive the required ingredients.
After a batch bucket exits the system onto the outfeed conveyor, it’s positioned on the checkweigh station so the PLC and operator can verify the total batch weight. The bucket is then conveyed to an area where operators manually add preweighed minor and micro ingredients, typically in amounts less than 1 ounce.The bucket then moves to a staging area before its contents are used in a product’s recipe.
The system,which is programmed so that a bucket can receive ingredients from one to 24 dispensers, can complete a batch in 4 to 8 minutes, depending on the number of ingredients.
Automated system improves production
The automated weigh batching system improved the quality control of the prepared-meats and kettlecooking operations. “Everything is done automatically now,” saysMaas.
“The system records each spice batch by lot number, detailing such information as recipe ID, ingredient quantity dispensed, and batch start and stop times, so we know exactly what goes into every batch. The system also improved the accuracy of the ingredient amounts in each batch, which minimized product loss and reduced operating costs. Additionally, the system reduced housekeeping costs because the ingredients room is much cleaner.”
Since installing the system, the labor and time required to make the spice batches has decreased. “We’ve been able to put a couple of employees to work in other areas in the plant,” says Maas. “And we’re only spending about ten hours a day, four days a week making spice batches, which means we can handle future production increases. I feel very comfortable and confident moving forward using the supplier’s system.”
According to Maas, the supplier was easy to work with when designing and installing the custom system. “They were here throughout the installation and start-up process,making sure that all the hiccups got resolved,” he says. “And they have great follow-up service and have been very responsive whenever we’ve had issues with the equipment. The system was well worth the capital investment.” PBE Note: Find more information on this topic in articles listed under “Weighing and batching” inPowder andBulk Engineering’s comprehensive Article Index in theDecember 2008 issue and at PBE’sWeb site, www.powderbulk .com, and in books available through theWeb site in the PBE Bookstore. You can also purchase copies of past PBE articles at www.powderbulk .com.
Ingredient Masters, Cincinnati, OH 513-231-7432
