How to Tackle Quality Problems Related to Mixing

A 30-second video of a liquid surface or powder batch during mixing can provide information about both properties and processing. Process viscosity or bulk powder behavior can be difficult to sample and measure with instrumentation. Even the desired quality standards may fail to capture the process conditions. For example, quality control may be done at a standard or final temperature, while the actual conditions in the process equipment may be different. Sometimes a photo or short video is all that is needed to communicate important mixing or product behavior. A video of a previous batch may show similarities or differences with current conditions. Careful observation of a video timed with a stopwatch may even provide a way to measure the rotational speed of a mixer without a tachometer.

If the storage and handling conditions for ingredients are subject to question, consumer weather instrumentation may provide temperature and humidity information compatible with a digital computer. Humidity can always affect the handling of powdered ingredients. One of the most commonly overlooked measurements is the initial temperature of the ingredients or process water.

Food ingredients and processes typically are cost sensitive. Cost limitations are justification for greater creativity in the use of technology. For instance, if a photo or video of a mixing operation may be beneficial, an expensive camera is probably not the best option. People take cell phone pictures of their food at restaurants all the time. Why not record what food looks like when it is being made? Videos at each ingredient addition or process change may provide a more complete view of the process steps. Time stamps on photos or videos may provide information about how long the process took. Every photo taken with a cell phone has a date and time in the details about the photo. For a continuous video of the process, a basic security camera with an overhead view and a digital recording device may provide information about the entire process at a minimal cost. Observation and recording can be as extensive as appropriate to monitor success in production. If you are still experiencing inconsistencies, you have not identified important differences in the process.

No Excuses

Mixing is an empirical process, which means that results are obtained by observation. Sophisticated computers and instrumentation may provide more detailed information than is necessary for success. If you experience process problems, learn about your products and operations through observation. Many problems and potential improvements may become obvious. Remember, you can’t keep doing the same thing and expect different results. Something needs to change.

Dickey is a consultant with MixTech, Inc., which specializes in all types of mixing processes and equipment for both liquids and powders. Reach him at [email protected].