Inside the High-Intensity Mixer: The Science Behind Consistent Quality

While “high-intensity mixing” does not have a universal definition, it generally refers to a category of process mixing equipment that expends high amounts of energy and force to blend challenging products. 

As we look past this simple description, the details of high-intensity mixing start to widely differentiate between industries and applications.  

Let’s look at the engineering science of high-intensity mixing in industrial process applications and highlight how this type of mixing process promotes a unique level of product consistency unobtainable with most other mixing technologies. 

We promise to keep it at a Mixing 101 level.    

When and Why High-Intensity Mixing Is Used

To a lot of readers, high-intensity mixing is equivalent to high-shear mixing. While that is one major component of high-intensity mixing, there are multiple other functions that these mixers perform (again, depending on industry and application). Overall, high-intensity mixers provide many paths to consistent product quality, such as:

• High shear: High-intensity mixers often feature a high-shear mixing head, which creates extreme fluid turbulence by forcefully driving materials against each other in a pulverizing fashion. This high-shear effect instantly breaks down and combines ingredients, creating a homogenous mix of otherwise immiscible materials.  
• High speed: Some products only need high-speed mixing without the high-shear effect to achieve consistent blends. In these applications, ingredients are typically very similar in physical properties, so there’s no need for pulverization to normalize particle sizes. High-speed mixing simply ensures that ingredients disperse evenly by “throwing” materials at a high speed off the mixing head. 
• Aspiration: A large swath of chemical applications uses high-intensity mixers for powder blends that must hit a critical moisture content specification, which can be achieved by designing the mix system for active aspiration. In these cases, the high-intensity mixer channels air through the mix to coerce evaporative dehumidification, hitting low moisture consistency as its main goal. 
• Agglomeration: This process improves powder product quality and performance by increasing the powder’s mean particle size, typically achieved via an added binding agent that particles can build around. In other words, high-intensity mix agglomeration converts fine powders into coarser powders, making them easier to handle, hydrate, disperse and store (with less dust, too). 
• Granulation: In simple terms, granulation is a step up from agglomeration, building large, finished products such as tablets and beads from very small initial particles. High-intensity mixers are used for granulation as well, where both mixing of disparate ingredients and agglomeration around a binding agent occur simultaneously under high speed, compound mixing action. 
• Thermal treatment: Most high-intensity mixers involve some level of thermal treatment, whether it’s internally generated heat from extreme friction forces or secondary thermal energy from an external source (such as steam heating or glycol cooling). This thermal treatment always serves a process purpose, such as aiding shear action, catalyzing chemical reactions or removing exothermic heat. 
• Particle reduction: Yet another function of high-intensity mixing is discrete particle size reduction, which can stand separate from high-shear mixing. In these applications, product particles can be reduced and normalized to a consistent dimension through any range of low- to high-force mixing actions, serving the purpose of standardizing materials before more critical unit operations.  
• Quality improvement: High-intensity mixing is often selected to improve a product’s quality specifications, such as in stabilizing suspensions, normalizing dye coverage and drying damp blends. For these functions, high-intensity mixing is selected for its ability to quickly and consistently improve the physical property of concern without over-processing the product (as with excessive handling or long blending).

Achieving Premium Product Quality with High Intensity Mixing

There’s nothing like actual examples to help visualize complex concepts, so let’s run through a handful of applications where high-intensity mixing proved to be the ideal solution for consistent quality production:

• Electric battery compounds: Mass battery manufacturing for vehicle and powered equipment involves multiple high-intensity mixers (such as the Lodige Vacuum Shovel Dryer), namely to standardize dry powder profiles such as graphite and lithium oxide before downstream slurry mixing into anode and cathode fluids.
• Engineered plastics: Many engineered plastics utilize high-intensity mixing all throughout the value chain, from raw feedstocks (like PVC) to extrusion pellets (like nylon), polymeric coatings (like vinyl sealer) to advanced additives (such as polycarbonate flakes), and more. In fact, high-intensity mixers are becoming more common in plastic recycling applications too, as they offer higher material recovery yields.
• Hazardous materials: Another high-value application type for high intensity mixers is in handling corrosive, combustible, flammable, reactive and other hazardous materials such as waste sludge, fly ash, aggressive chemicals and coal ore. These applications tend to best benefit from continuous mixer operation, like with the Lodige Continuous Ploughshare Mixer to hit consistent specs over extended runs. 
• Pigments and dyes: Dry and fluid colorizing ingredients are notoriously sensitive to over-processing and excessive handling, which makes them great fits for high-intensity mixers designed specifically for high speed, active cooling and quality standardization. In addition, high-intensity mixers built for high cleanability greatly improve dye batch turn-around with minimal carry-over.  
• Functional beverages: High-intensity mixers are widely used in hygienic markets from pharma to pet food, with a significant presence in complex food processing such as functional beverages. These beverage recipes often handle difficult, temperature-sensitive powder dispersion, such as blending whey protein powder into a cold dairy base, which high-intensity mixers can easily tackle. 

Mixing 201: Advanced Studies in High-Intensity Mixing

If you’re looking for even more in-depth information on the science and mechanics of high-intensity mixing, we’re eager to answer your questions directly via phone, email or direct message here.