Continuous mixers can produce a wide variety of baked goods ranging from crackers and bagels to soft bread and buns. Source: Reading Bakery Systems

Maybe it’s in their rugged DNA or because of their stainless-steel armor. Mixers seem to last forever. Even today, it’s not unusual to walk into a bakery with rebuilt JH Day horizontal mixers that are 50 years or older. They didn’t call them the Hercules models for nothing.

But good genes don’t guarantee that even the sturdiest of machines will never break down. All equipment contains those wear parts that could suddenly shut down the entire production line if not carefully monitored and replaced on a regular basis. And yes, once in a while, a catastrophic failure results in extended downtime.

However, it doesn’t necessarily have to happen. Often skilled operators who know their machine like a personal friend can tell when something is wrong. In many cases, they can’t help but hear when a mixer isn’t feeling up to par, said Damian Morabito, president, Topos Mondial Corp.

“My dad always said, ‘The machine will talk to you before it dies,’” Mr. Morabito pointed out. “The operators know their machines because they’re very close to them every day. They need to be trained to say, ‘If it feels different, performs different or makes a different noise, alert us.’ They need to tell the engineer if something changes. These machines usually don’t give up the battle at once. They usually move slowly to a failure.”

In other cases, the sense of sight keeps everything running right.

“Good training educates the operator where to look and what to look for,” noted Hans ten Hooven, sales project office, Haas-Mondomix. “Most of the operators know when something is out of the ordinary while working with the machine on a daily basis. Usually, they are the first ones who will know or see differences in the performance of the machines. It is indispensable to take these notifications seriously.”

Everyone agrees that following a preventive maintenance schedule will boost the reliability and extend the life of a mixer.

“A proactive maintenance program maximizes the uptime for the mixer and reduces the risk of unplanned downtime,” observed John Hunter, sales account manager, bakery and ingredient handling, Bühler, Inc.

There should be no hesitation on changing a wear part when it is time to replace it.

“A bearing can ‘look good,’ but when it is at the end of its life, it is going to fail,” said Bobby Martin, executive product manager, AMF Bakery Systems. “Wear parts will fail when machines are running, therefore impacting maintenance and production with unscheduled downtime.”

Although mixers may be as tough as a pickup truck, they need a peek under the hood to keep them running smoothly.

“If people would take care of their mixers the way they take care of their cars — regular maintenance and inspecting them three times a year — they would have no problems,” said Jim Warren, vice-president, Exact Mixing, Reading Bakery Systems (RBS). “This goes for batch and continuous mixers — or any other piece of equipment in the plant. If you take care of it and do regular maintenance, you’ll have a long and successful history. If you don’t do those things, like changing the oil in your car, it will break down, and you’ll have to fix it.”

Specifically, the type of lubrication and its timely application become critical to maintaining a mixer’s performance.

“Many bakeries are switching to food-grade H1 greases, and they must consider that not all these lubricants are appropriate for mixer use,” explained Joe Spaugy, technical sales manager, Shaffer, a Bundy Baking Solution. “There are food-grade lubricants that are properly formulated for mixers, and bakeries need to verify an H1 grease is approved by the manufacturer.”

Even if mixers are properly maintained, operator errors and improper mixing procedures, especially involving firm doughs, can damage even the most durable system over time.

“If you’re making a very dry or stiff dough, you need to start out mixing at low speed until the ingredients get incorporated and then run it at a higher speed,” Mr. Warren said. “Abusing it often occurs by not prehydrating the ingredients or running the batch first in low before switching to high speed.”