Increased automation gives bakers greater control over their process. With the widening workforce gap and many “dough heads,” with all their knowledge, heading for retirement, automating the mixer will become a critical step in the bakery.
“All bakeries are finding it difficult to find qualified workers or even people prepared to work the hours a commercial bakery requires,” said Andrew McGhie,
director of sales, Shaffer, a Bundy Baking Solution. “The baking industry is not as sexy as we’d like it to be as far as attracting people, so typically, labor is hard to get and very expensive, so automation is always something people are looking for.”
Streamlining the mixing process brings a greater level of consistency to dough development unmatched by manual operations.
“The second thing automation does is remove the human error factor,” he continued. “Now ingredients are automatically added and mix times are programmed, so there’s very little opportunity for error.”
Deciding to invest
Increasing automation at the mixing stage takes a capital investment. It requires more money upfront than simply purchasing a new mixer.
“Automation requires a greater investment than manual; therefore, the technology is not feasible for all bakeries,” said Bobby Martin, executive product manager, AMF Bakery Systems.
There are some signs that indicate a bakery is ready for this level of automation and that the investment will be worth it. Consistent loss of minor and micro ingredients is one of those signs.
“A lot of times that’s an indication that the operators are throwing out bags of expensive micros with ingredients still left in them,” said Joe Cross, process manager, Zeppelin Systems USA. “That type of loss starts adding up.”
A bakery may have automated flour and sugar delivery to the mixing bowl for years, he said, but this might be an indication that it’s time to take the next step and automate delivery of the micro and minor ingredients as well.
Because automation often addresses workforce issues, Mr. McGhie suggested bakers evaluate if they should hire a skilled operator for the mixing station in production.
“Ask yourself ‘Can I recruit someone for that position? Can I keep someone in that position?’” he said.
It’s also easier to automate the mixer and its handshake with the systems around it when starting up a new plant or production line. It requires an optimal production line layout, which is more ideal when working with the blank slate of a new bakery.
“For an existing installation, it can be a harder decision to make because in an existing facility I can’t lay out all of the equipment,” Mr. McGhie said.
If a bakery decides automation is something for the future, AMF uses a systematic approach to the design and project management process to meet current production needs and prepare for automation down the road. This process ensures that new equipment is installed in an optimal location for immediate use in conjunction with the manual process’ needs. It also allows adequate space for potential automation retrofitting in the future.
More consistency in the bowl
On its own, mixer functions can be automated extensively to improve mixing efficiency.
“Above all, automation allows consistency in dough production and thus to avoid losses, any variation of production, to satisfy the consumer’s expectations of quality product,” said Terry Bartsch, president and chief executive officer, VMI North America. “The tasks performed are accurate and repeatable, which ensures that all batches are produced with the same specifications and that they will have the same quality.”
This is made possible by recipe programming. Bakers can enter mixing times and speeds into a program for each product, and the mixer will repeat that process every time an operator chooses it.
“While reducing labor is one advantage to automation in mixing, the real value resides in the repetition of the same variables over and over within each pre-programmed recipe setting,” Mr. Martin said. “Once the recipe is finalized during start-up to the baker’s satisfaction, the recipe setting is then registered to ensure the mixer follows the same exact process through every other mixing cycle.”
A recipe can be as simple as mixing at a pre-determined speed for a specific amount of time or as complicated as stopping and bowl lifting and adding more ingredients in the middle of the mix.
“The recipe can be 10 or 20 or any number of steps that are executed automatically,” said Ondrej Nikel, director of engineering, Topos Mondial Corp. “The mixer can execute the entire process, or it can stop, and an operator can step in and confirm that a certain amount of inclusions has been added before continuing the mixing process.”
Dough monitoring also improves the mixer’s efficiency and ensures that doughs are not over- or under-mixed. Automated dough mixers today track the mixing curve and stop the moment when dough is fully developed. As gluten is developed in the mixer, the load increases and peaks before dropping off. This drop-off signals that the dough has been fully mixed.
“It’s a common practice to mix to a given time,” Mr. Nikel explained. “But it can be helpful to have the automated feature that tracks how hard the mixer is working. The variable frequency drive (VFD) is reading the amps. When the electrical current that’s flowing to the motor peaks, we know the dough is developed, and mixing can stop.”
Spooner Vicars’ horizontal dough mixer monitors the parameters of time, speed, energy and temperature, whichever the baker prefers. To measure temperature, the mixer’s sprag feature has a temperature sensor attached to a fixed stator at the bottom of the bowl.
“With certain doughs, temperature is absolutely critical,” said Gerard Nelson, sales director, Spooner Vicars.
The intelligent dough monitoring systems that Shaffer equips its mixers with records the mix profile, eliminating the need for an operator to decide to stop the mixer. The system records the dough temperature, time and amps so operators can evaluate the profile historically or in real time. This allows them to notice any changes in the dough caused by deviations in flour or environment. Operators can even program the system to respond to certain parameters and set an alarm to alert them if something is out of spec.
“One concern old-school bakers have about automation is that no one is going to be looking at the dough before processing it,” Mr. McGhie said. “They know when the dough is good, and if it’s not good at the mixer, then it’s going to be bad all the way down the line. Having some way to monitor the dough quality as it comes out of the mixer is very important.”
WP Bakery Group’s Kemper Kronos Digital also enables operators to simply push a button for an optimal mix. The machine adapts itself to a product’s process parameters based on sensor measurements.
“We are scanning in real-time factors like temperature, torque of the motor and resistance of the dough, along with all other important parameters to get to the result required by the bakery,” said Patricia Kennedy, president and c.e.o., WP Bakery Group USA.
Another way to improve the efficiency at the mixer and cut down on mixing times is to pair the batch mixer with a pre-hydration system. For example, Zeppelin and WP Bakery Group partnered to pair Zeppelin’s DymoMix pre-hydration system with the WP Kemper Kronos bowl mixing system.
“You pre-hydrate all of the ingredients via the DymoMix feeding the kneader, and all the operator has to do is press one button, and the machine will stop itself at the ideal point to reach the optimal dough development,” Ms. Kennedy said.
This enables bakers to reduce mixing times by up to 50%.