Infographic: 8 tips for powder mixing

In a powder mixing/processing system, blending is one of the most significant functions. An increasing challenge in the powder handling industry is how to accommodate a wide portfolio of recipes and vast array of different ingredients, several of which pose an allergen risk. Choosing a blender from the extensive options available can be confusing and overwhelming.

Check now

Whether a beginner or seasoned professional, these tips from Dan Ruble&#;s &#;8 blender selection considerations for powder mixing plants&#; will help guide you to the best choice for your application.

Munson Machinery Co., Inc.

When it comes to mixing nutraceutical ingredients, not all blenders are created equal. Because there&#;s a wide range of particles in each &#;mix&#;&#;of different sizes and bulk densities&#;getting the right result requires choosing the right blending action to achieve the desired outcome.

Selecting the best equipment for the application is necessary to maintain rigid end-product quality standards and support nutritional claims on the label. Further, blends requiring trace amounts of critical ingredients and/or liquid additions must be dispersed with near 100% uniformity throughout the batch, and maintain that uniformity from the first to the last ounce discharged from the blender.

An effective blending operation is therefore critical to the quality of nutraceutical products, as well as to the plant&#;s productivity measured in blending cycle times, cleaning/ sanitizing downtime, capital costs, energy consumption, and maintenance costs.

The blenders most commonly specified for nutraceutical processing are:

• Tumble-type mixers
• Ribbon/paddle/plow blenders
• Vee cone blenders

All should be offered in a range of sizes for full-scale production down to low-capacity units for small-scale production and laboratory testing.

Rotary Batch Mixers

Rotary Batch Mixers impart a gentle four-way mixing action that folds, tumbles, cuts and turns the material, causing particles to recombine 288 times per minute, typically achieving uniform blends in one to three minutes. This blending action imparts minimal energy and intensity to nutraceutical ingredients while preventing segregation regardless of particle sizes, shapes or bulk densities. With optional internal nozzles, the tumbling action provides a wide fluid bed on which to spray liquid additions or coatings for rapid dispersion throughout the batch.

Full-scale models are available in capacities from 10 to 600 cu ft (0.3 to 17 m3 ). Also available are lab scale/pilot Rotary Batch Mini Mixers in capacities from 0.25 to 15 cu ft (7 to 425 liters). Unlike other types of mixers/blenders, results achieved in lab size models are scalable to full production capacities.

Pros:

• Greatest Blend uniformity
• 1 to 3 minute cycle times
• No internal shaft, bearings or seals
• Equally efficient from 100% to as low as 15% of rated capacity
• Complete discharge with no segregation
• Fast sanitizing
• Complete internal access
• Most gentle
• Stationary inline configuration
• Lowest maintenance
• Lowest energy per amount blended
• Uniform liquid additions
• Lowest operational cost
• Capacities from 0.25 to 600 cu ft (7 L to 17 m3 )

Cons:

• Not suited for pastes, slurries or sticky materials
• The higher initial cost for smaller units

Ribbon/Paddle/ Plow Blenders

Ribbon blenders feature a stationary U-shaped vessel and a single, horizontal shaft with radial arms supporting agitator elements. Unlike tumble-type mixers, these sanitary blenders force agitators through stationary material, creating shear, which accelerates the dispersion of individual particles into liquids. As a result, they can blend solids with solids, as well as solids with low or high percentages of liquids to produce smooth pastes or slurries.

Mixing capacity is approximately 70 to 80% of total vessel volume, which provides ample space for complete agitator contact with batch materials and proper distancing of an optional spray manifold for introducing liquid additions, resulting in uniform solids/liquids distribution.

These horizontal blenders come equipped with double helical ribbon, plow or paddle agitators and are easily customized to suit any nutraceutical application with optional internal spray lines, heating and cooling jackets, high-speed choppers and intensifier bars, and an extensive selection of drives, covers and discharge gate designs.

dahe Product Page

Pros:

• Fair to good blend uniformity
• 5 to 10 minute cycle times typical
• Lower initial cost on smaller units
• Ability to handle powder to pastes
• Ability to handle sticky/tacky materials
• Stationary inline configuration
• Optional internal spray lines
• Capacities from 1 to 1,150 cu ft (28 L to 33 m3 )

Cons:

• Agitator blades shear/degrade fragile materials
• A residual &#;heel&#; of materials remains after discharge
• Longer cleaning times
• Two internal shaft seals that contact material
• Higher operational cost
• Highest energy used per amount blended

Vee Cone Blenders

Vee cone blenders are best suited for free-flowing dry powders or granules. Two inclined cylinders cause bulk material to gently fall and converge, then divide with each rotation, achieving uniform blends typically in as little as 15 minutes with equal efficiency at fill volumes from 100% to 25% of rated capacity, depending on material.

If the gentle blending action is insufficient to break down soft agglomerates, an optional intensifier bar can be used to impart shear.

Smooth interior surfaces allow complete discharge and rapid, thorough sanitizing. Vee cone blenders are available in laboratory to full-scale models from 1 cup (1.5 L) to over 200 cu ft (5.6 m3 ). Large models require more floor space and headroom than other mixers of equivalent capacity.

Pros:

• Fair to good blend uniformity
• Complete discharge
• Fast sanitizing
• No bearings or seals in contact with the material
• Optional spray lines
• Blending action more gentle than agitated machines
• Low operational cost

Cons:

• Not suited for pastes, slurries or sticky materials
• Blend times as little as 15 minutes
• Longer blend times can degrade material or overmix and segregate
• Large area required for vessel swing
• Mixer must be indexed to load/unload
• Ineffective at less than 50% capacity
• Spray lines on the centerline can cause lumps, removable with an intensifier that may impart shear/degradation

Document performance using your actual material

It is critical to document the performance of any blender before making the purchase. First, speak with experts from reputable manufacturers of all three types of blenders to obtain objective advice. Then avail yourself of the manufacturer&#;s test laboratory to quantify the performance of each blender using your actual material, thereby assuring a successful result following installation. Equipment manufacturers usually test customer materials at no charge, but charge for shipping of materials.

Munson offers 17 high-performance equipment lines, each with numerous models to meet specialized requirements in the chemical, pharmaceutical, nutritional, food, coffee/tea, refractories, powder metal, and other industries.

Case Study: How One Manufacturer Solved Mixing and Blending problems

Phoenix Custom Manufacturing produces and packages nationally recognized brands and private-label protein powders, amino acids, functional foods and encapsulated dietary supplements. Some products have just two ingredients and others as many as 50.

The company recently replaced a vee cone blender with a 90 cu ft Rotary Batch Mixer, which handles protein and amino acid powder applications, while the company&#;s conical and smaller tumble blenders mix lesser-volume products.

According to Eric Manfull, general manager, it takes one hour on each end to load and unload the conical blender of a 1,323 lb (600 kg) batch, whereas the Rotary Batch Mixer can be charged with twice as many ingredients in 15 to 20 minutes and discharged in 10 minutes.

The mixer is installed in a dedicated room that houses a bag dump station and vibratory sifter. To load the mixer, an operator empties 25 kg (55 lb) bags of ingredients into the bag dump station which feeds the material to the sifter. On-size material passing through the sifter flows past rare earth magnets and into a chute connected to the mixer&#;s inlet, which remains stationary as the vessel rotates.

The company says that with the new Rotary Batch Mixer volume is up fivefold, labor is down by half, airborne dust is down 90 percent, blends are more homogenous, and a 9-month production backlog has been cleared.

Stay up to date with the latest news, articles, and events. Plus, get special offers from Tablets & Capsules &#; all delivered right to your inbox! Sign up now!

The company is the world’s best powder blender supplier. We are your one-stop shop for all needs. Our staff are highly-specialized and will help you find the product you need.