The design of many mixers limits water-retention areas and allows for high-pressure cleaning. Source: VMI

Avoiding bad breaks
When a mixer stops functioning, it’s never a good situation. That’s especially true in small- to mid-sized operations where if the main mixer goes down, the whole operation grinds to a halt.

Certainly, bad things eventually happen in any bakery, but in many cases, good manufacturing practices can minimize how often they occur, said Mr. Spaugy, who provided a helpful checklist of what to monitor when it comes to horizontal mixers.

“If batch size is too large or agitator RPM too high, a mixer’s variable-frequency drive (VFD) can be at high risk of shutdown,” he said. “It’s important to ensure that motor fans are clear of debris. The motor bearings should be greased properly, and the motor and reducers should be aligned properly. Reducer gear oil should be changed per preventive maintenance schedules.”

He recommended setting the drive belt and chain tensions accurately, lubricating all chains regularly and examining sprockets for signs of wear. The agitator bearings should be greased routinely. Additionally, check agitator bolts for proper torque on the hubs and spiders.

On all mixers, maintain and protect all electrical components.

“It is critical that all electrical covers, doors and panels are kept closed properly to prevent flour dust and water from damaging the components and creating safety issues,” Mr. Spaugy said. “Loose or faulty wiring can also be a culprit of downtime issues as well.”

With horizontal mixers, examine roller-bar bushings to ensure they are not wearing or breaking apart. Likewise, maintain correct bowl tilt.

“The hydraulic power units need to be serviced properly and with attention to hydraulic hoses and tilting components,” he added. “The bowl trunnions must be lubricated per the proper preventive maintenance schedule as well.”

One significant challenge involves the type of spare parts — and how many of them — to keep on hand. Bakers and snack producers should keep a full supply of normal, scheduled wear parts, said Mr. Warren. Catastrophic parts probably will never break, but if they do, the mixer won’t run until they’re replaced. A third type of part involves those components that can be purchased at nearby stores.

To minimize inventory, he suggested standardizing components used throughout the bakery.

“The justification is that you can buy one type of motor, and it’s a spare for 30 motors in your plant,” he explained.