The Role Of Ribbon Mixers In The Food Industry

Jun 02, 2023

Mixers and blenders play a critical role to transform raw ingredients for human consumption. Whether it's blending multiple ingredients in high volume or small-scale mixing by hand, proper mixing is essential to create consistency. Even with the right amounts of flavors and ingredients, a great recipe won't transform into good food unless its components are well-incorporated.

Appearance, color, taste, and texture are critical parameters influenced by the mixing process. Consumers expect their food items to be the same as their last experience. So, within the food industry, the right blender for the job can provide a high level of consistency. This could be present through each batch and also from one facility to another.

One of the most universal types of blenders in the food industry is the ribbon mixer. This article talks about the basics of a ribbon mixer and its role in the food industry. It also includes choosing the right machine, whether finding used ribbon mixers or investing in new ones.

What Is A Ribbon Mixer?

A ribbon mixer consists of a U-shaped horizontal trough with a double or single helical ribbon agitator rotating within it. The outer and inner helical ribbons are pitched to axially move the material in opposite directions, as well as radially.

The ribbon tip speeds can rotate up to 300 feet per minute. This ensures blending and mixing to the highest degree of efficiency and accuracy regardless of the available quantities of ingredients.

The Role of Ribbon Blenders In The Food Industry

A ribbon mixer is popularly used in a variety of industries, but mostly in the beverage and food industries.

The design of a ribbon blender makes it cost-effective and highly efficient for mixing dry applications. It is used in mixing dry food products such as muffin and cake mixes, cereals, bread improvers, spices and herbs, snack bars, trail mixes, infant food, and dietary supplements.

In terms of beverages, ribbon blenders can mix coffee, including ground or whole beans. Tea, such as tea powders or leaves, chocolate drinks, whey protein, energy drinks, and powdered juices are some products that could use a ribbon mixer.

Although dry blending is its more popular function, a ribbon mixer can also be used in the preparation of flowing pastes or slurries. This could be used in food extrusion operations. Food extrusion is a processing technology to produce a wide variety of food products from ready-to-eat cereals and pasta to pet food and snack chips.

The role of a ribbon mixer in the extrusion process is to homogeneously mix two or more flour, grains, emulsifiers, sugar, extrusion aids, oil, and other powders. Once the constituents are blended, water is typically added to the batch to raise the existing moisture content to a proper level of extrusion.

Liquid ingredients are often added through a charge port on the cover. For critical applications, a liquid ingredient is added via spray nozzles installed in a spray bar located just above the ribbon agitator. Oftentimes, liquid flowrate and blender speed are fined-tune during mixing to avoid the formation of wet clumps of powder or flooding the mixture's consistency.

Unlike other machines, a ribbon mixer features a double ribbon agitator, making it a highly versatile machine not only for mixing but also for other purposes such as:

How To Choose The Right Ribbon Blender

If you’re into the food processing business, then you need to get a ribbon mixer. Here are some tips on choosing the right one for your business.

The size and volume of the ribbon mixer are the most important factors to consider when choosing a ribbon blender. This depends on the number of food materials you’re mixing and the required speed to blend them all.

As a general rule, a ribbon blender should be filled to its swept volume, which is the area occupied by the agitator, to get an efficient mix. So, if you’re processing materials that overfill its swept volume, you need to get a larger one.

To get the best mix in the shortest period, the mixer size is also essential. The mixer length should not exceed two and a half times the diameter of the agitator. Also, consider the width, length, volume, and height of the machine, as well as the agitator size, to ensure the perfect size for your food processing needs.

Ribbon blenders are usually made from mild steel or stainless steel. However, the materials of construction and its finish will depend on the ingredients being mixed and how these ingredients are going to be used.

For instance, in the case of food-grade ingredients, blenders should be stainless steel with special weld finishes. This is so that the machine can be easily sanitized and cleaned. Meanwhile, the exterior or non-contact areas of the ribbon blender can be made from mild steel and painted. This is in contrast with its interiors where paint can contaminate the ingredients being mixed.

The machine can also be layered with a material such as ceramic or Ultra-High Molecular Weight (UHMW) plastic. This might be used to enhance its longevity and performance. Also, this is usually seen when a material is abrasive and can prematurely wear out the interior parts.

To choose a mixer that's both efficient and effective, you need to use a motor with enough horsepower. Choosing a motor that's too powerful can mean extra expenses. However, underestimating the motor power can result in the mixer not being able to process your general ingredient load.

Most ribbon blenders operate at 20 revolutions per minute. Mixers with wider ribbons or dual agitators will require more power. A general rule of thumb for medium density material in single-agitator ribbon mixers is 10 horsepower per ton of the ingredient being mixed.

How the ingredients exit the blender is also an essential factor to consider. Some processes will need immediate discharge. In this case, a full-length drop bottom discharge gate is essential. It releases the ingredients immediately after mixing.

Some processes may require a pneumatic slide gate that releases gradual discharge, allowing a set amount of material to escape. This is useful for batching, measuring, and bagging ingredients after mixing. If you need a faster discharge rate and a tight seal, you can use multiple gates to speed up the process.

Conclusion

There's no doubt that mixing and blending is the heart of the food processing and manufacturing industry. Thanks to its high-speed and efficient blending abilities, ribbon blenders have always been a necessity for getting the right consistency in your food products.