Double Arm Mixer Glossary
A Guide to Double Arm Mixers, Sigma Mixers, Kneaders and High-Viscosity Mixing Terms
Industrial mixing terminology can get confusing quickly.
One manufacturer may call a machine a Double Arm Mixer. Another buyer may search for a sigma mixer, Z-blade mixer, kneader, high-viscosity mixer, or mixer-extruder.
Sometimes those terms overlap. Sometimes they describe a particular blade style, process, or equipment configuration.
This glossary is designed to help engineers, plant managers, maintenance teams, and equipment buyers understand the terminology used when evaluating Double Arm Mixers and other equipment for demanding high-viscosity applications.
The most important principle is simple:
Start with the material and process requirements first. Then determine the appropriate mixing technology and equipment configuration.
A Double Arm Mixer is not automatically the best mixer for every application. It becomes the right choice when the material and process requirements call for the mixing behavior and equipment characteristics it can provide.
Double Arm Mixer Terms & Definitions
Application-Specific Configuration
The way a mixer is designed or configured around the requirements of a particular material and production process.
A Double Arm Mixer may require different blades, torque, power, temperature control, discharge systems, seals, drives, materials of construction, controls, or other features depending on the application.
Why it matters: Choosing the mixer type is only part of the equipment decision. The machine still needs to be configured around what the material and process demand.
Auger Discharge
A discharge method that uses a rotating screw or auger to move material out of the mixing chamber.
Auger discharge can be particularly relevant when the mixed material does not flow easily on its own.
Why it matters: Discharge is part of the process. A material that mixes successfully but cannot be efficiently removed from the mixer can still create a production bottleneck.
Batch Double Arm Mixer
A Double Arm Mixer designed to process a defined quantity of material as an individual batch.
Material is loaded, mixed according to the required process, discharged, and the cycle is repeated.
Why it matters: Batch processing may be appropriate when production requires defined recipes, controlled batch sizes, formulation flexibility, or separation between production runs.
Batch Mixer-Extruder
A Double Arm Mixer configuration that combines batch mixing with an extrusion or auger-assisted discharge system.
The material is mixed as a batch and then mechanically discharged through the extrusion system.
Why it matters: This configuration can be useful for dense, sticky, or high-viscosity materials that are difficult to discharge through gravity or tilting alone.
Batch Processing
A manufacturing process in which material is produced in separate, defined quantities rather than in a continuous flow.
Why it matters: Whether a process should be batch or continuous can influence mixer design, throughput, material handling, discharge, automation, and the overall production system.
Blade Configuration
The geometry, arrangement, and operating relationship of the mixing blades inside a Double Arm Mixer.
Different blade configurations can change how material moves through the mixer and how shear, turnover, kneading, and energy are applied.
Why it matters: Blade selection should follow the material and process requirements rather than being treated as a standard feature choice.
Bottom Dump Discharge
A discharge configuration that releases material through an opening in the bottom of the mixing trough.
Why it matters: The best discharge method depends on material behavior, downstream processing requirements, production layout, and how easily the material flows after mixing.
Continuous Mixer-Extruder
A Double Arm Mixer configuration designed to receive, mix, process, and discharge material continuously rather than as separate batches.
Why it matters: Continuous processing may become relevant when production requirements emphasize sustained output, scale-up, consistent material flow, and efficient downstream processing.
Continuous Processing
A manufacturing method in which material moves through the processing equipment continuously rather than being produced as individual batches.
Why it matters: Moving from batch to continuous processing is more than an equipment change. Throughput requirements, residence time, material feeding, discharge, controls, heat management, and downstream equipment may all influence the decision.
Deaeration
The removal or reduction of trapped air or gas from material during processing.
Sticky or high-viscosity materials can sometimes retain air during mixing.
Why it matters: Trapped air may affect product consistency or downstream processing in certain applications. The need for deaeration should be evaluated as part of the overall process requirements.
Discharge Method
The system used to remove processed material from the mixer.
Common Double Arm Mixer discharge approaches can include tilting, bottom dump, and auger-assisted discharge.
Why it matters: Discharge should be considered during equipment selection, not after the mixer has already been specified. Material viscosity, tackiness, production flow, downstream equipment, and cycle time can all influence the appropriate method.
Double Arm Kneader
Another industry term commonly associated with Double Arm Mixers used for kneading dense or high-viscosity materials.
Buyers may use Double Arm Kneader or Kneader Mixer when they are thinking primarily about the action required to process the material rather than the formal equipment category.
Why it matters: Different industries often use different terminology for similar equipment.
Double Arm Mixer
A horizontal industrial mixer using two mixing arms or blades to process materials inside a mixing trough.
Double Arm Mixers are commonly considered for demanding materials where the process requires combinations of kneading, folding, turnover, shear, and significant torque.
They are often associated with dense, sticky, heavily filled, and high-viscosity materials.
Why it matters: “Double Arm Mixer” describes the equipment family. The appropriate DAM type and configuration still depend on the material and process.
Energy Applied
The mechanical energy transferred from the mixing system into the material during processing.
The amount and manner in which energy is applied can influence how effectively the material is mixed, dispersed, kneaded, or otherwise processed.
Why it matters: Industrial mixing should not be reduced to a simple question of whether a mixer creates “shear” or “flow.” Flow pattern, shear, turnover, and energy applied all contribute to how material behaves inside the mixer.
Flow Pattern
The way material moves and circulates through a mixer during operation.
Why it matters: Effective mixing depends partly on whether material is moving through the mixing zone in a way that produces the required turnover, contact, and processing action.
Two mixers may both create material movement while producing very different flow patterns.
Heat Management
The control of material and equipment temperature during processing.
Double Arm Mixer systems may incorporate different temperature-management approaches depending on the equipment type and application, including jacketed troughs and other integrated heating or cooling systems.
Why it matters: Mixing difficult materials can introduce or require heat. Material properties, product quality, cycle time, viscosity, and downstream processing may all be affected by temperature.
Heavy-Duty Mixing
Mixing applications involving demanding material loads and production conditions that place substantial requirements on the equipment.
For Double Arm Mixers, “heavy-duty” can refer to the engineering demands created by the material, such as:
- High torque requirements
- Higher power requirements
- Robust blades and shafts
- Heavy-duty drives
- Structural strength
- Sustained production duty
Why it matters: Heavy-duty should describe the demands of the application and resulting equipment design, not simply the physical size of the machine.
High-Viscosity Mixer
A broad search and industry term for equipment designed to process materials that strongly resist flow.
A Double Arm Mixer may be one high-viscosity mixing technology, but the correct mixer should be determined by the complete material and process requirements.
Why it matters: Viscosity is an important starting point, but it should not be the only factor used to select a mixer.
Jacketed Trough
A mixing trough designed with a surrounding jacket through which a heating or cooling medium can be circulated.
Why it matters: A jacket can provide a way to manage process temperature when the material requires heating, cooling, or tighter thermal control.
The appropriate temperature-control approach depends on the application.
Kneader Extruder
Another term buyers may use for a mixer-extruder configuration that combines kneading or high-viscosity mixing with mechanically assisted discharge.
Why it matters: Search terminology varies widely between industries. “Kneader extruder,” “mixer-extruder,” and related terms may describe similar equipment requirements from different buyer perspectives.
Kneader Mixer
An industrial term commonly used for mixers intended to knead dense, cohesive, sticky, or high-viscosity materials.
Depending on the application and industry, buyers may use kneader mixer, Double Arm Kneader, or Double Arm Mixer when discussing related equipment.
Why it matters: Orbis evaluates the required mixing process rather than relying solely on the equipment terminology used in the initial inquiry.
Kneading / Folding
Mixing actions in which material is repeatedly worked, compressed, stretched, folded, and moved through the mixing zone.
These actions can be particularly relevant for cohesive, dense, sticky, or highly filled materials.
Why it matters: Some applications require more than simple circulation. Understanding the physical action required inside the material helps determine whether a Double Arm Mixer is an appropriate technology.
Material Behavior
How a material physically responds during processing.
Relevant characteristics can include viscosity, tackiness, density, filler loading, temperature sensitivity, flow behavior, and how easily the material turns over or discharges.
Why it matters: Material behavior should be understood before selecting the mixer.
Two materials with similar stated viscosities may still behave differently during processing.
Mixer-Extruder
A Double Arm Mixer configuration that incorporates an extrusion or auger system to mechanically discharge material after mixing.
Why it matters: Mixer-extruders can address an important challenge in high-viscosity processing: successfully moving sticky or difficult-to-flow material out of the mixer and into the next production step.
Mixing Technology
The type of equipment and mixing mechanism selected to produce the required physical change in a material.
A Double Arm Mixer is one mixing technology among multiple industrial mixing options.
Why it matters: The correct sequence is:
Understand the material → define the process requirements → select the appropriate mixing technology → configure the equipment for the application.
Power
The rate at which mechanical work can be delivered by the mixer drive system.
Power and torque are related but are not interchangeable terms.
Why it matters: A demanding material may require an equipment design capable of delivering sufficient power and torque throughout the required operating conditions.
Process Requirements
The conditions and results the manufacturing process must achieve.
These may include requirements for:
- Mixing behavior
- Product consistency
- Batch or continuous operation
- Temperature control
- Throughput
- Discharge
- Material handling
- Shear
- Turnover
- Energy input
Why it matters: Process requirements should determine the equipment specification rather than selecting a mixer first and attempting to force the process to fit it.
Shear
A mechanical action created when adjacent portions of material move relative to one another.
Most mixers produce some combination of shear and material flow.
Why it matters: Describing one mixer as a “shear mixer” and another as simply a “flow mixer” can oversimplify what is actually happening.
The more useful questions are how much shear is produced, where it occurs, what flow pattern develops, how material turns over, and how energy is applied.
Sigma Mixer
A common industry term associated with a Double Arm Mixer using sigma-style blade geometry.
Sigma mixers are often discussed in connection with kneading dense, sticky, and high-viscosity materials.
Also called: Sigma Blade Mixer.
Why it matters: Many buyers search for “sigma mixer” even when they are ultimately evaluating the broader Double Arm Mixer equipment family.
Sigma Blade
A blade geometry commonly associated with Double Arm Mixers and industrial kneading applications.
Why it matters: Blade geometry influences material movement and mixing action, but blade selection should be based on the material and process rather than assuming one blade style is appropriate for every high-viscosity application.
Sustained Production Duty
The requirement for equipment to operate reliably under the loads and operating schedule of an industrial production environment.
Why it matters: A mixer that can move a material temporarily is not necessarily designed for the repeated loads of full production.
Heavy-duty industrial equipment must be engineered around both the material and the expected operating duty.
Tilting Discharge
A discharge method in which the mixing trough is tilted to help remove the processed material.
Why it matters: Tilting can simplify discharge for some materials, but the best discharge approach depends on the material’s flow behavior and the downstream process.
Torque
The rotational force delivered through the mixer drive, shafts, and blades.
Dense and high-viscosity materials can place substantial torque demands on mixing equipment.
Why it matters: Torque requirements influence the design of motors, gearboxes, drives, shafts, blades, and supporting structures.
High-viscosity mixing is therefore not simply about adding a larger motor. The mechanical system must be designed around the load.
Turnover
The repeated movement of material through different regions of the mixing chamber and back through the active mixing zone.
Why it matters: Effective turnover helps prevent portions of the batch from remaining relatively stagnant while other areas receive disproportionate mixing action.
When evaluating difficult materials, turnover can be just as important to understand as shear.
Viscosity
A measure of a material’s resistance to flow.
High-viscosity materials resist movement more strongly than low-viscosity fluids and may place greater mechanical demands on mixing and discharge equipment.
Why it matters: Viscosity is an important equipment-selection variable, but it does not tell the entire story.
Tackiness, filler loading, temperature, material behavior, required mixing action, discharge requirements, and other process conditions should also be evaluated.
Z-Blade Mixer
A related industry term associated with blade geometry used for kneading and processing demanding materials.
Buyers may use Z-blade mixer, sigma mixer, kneader, and Double Arm Mixer when researching related high-viscosity mixing technologies.
Why it matters: Search terminology does not always match equipment-manufacturer terminology. The application should determine the equipment rather than the label alone.
What Makes a Double Arm Mixer the Right Fit?
A Double Arm Mixer should not be selected simply because a material has high viscosity.
It may become an appropriate solution when the application involves characteristics such as:
- High viscosity
- Sticky or cohesive material behavior
- Heavy filler loading
- Difficult material turnover
- Kneading or folding requirements
- Controlled shear requirements
- Significant torque demand
- Difficult discharge
- Demanding production duty
The next question is then not simply “Do I need a Double Arm Mixer?”
It becomes:
What type of Double Arm Mixer does the process require, and how should that mixer be configured around the application?
The Double Arm Mixer Selection Process
A useful way to think through an industrial mixing application is:
1. Understand the Material
What are you processing?
Consider viscosity, tackiness, filler loading, temperature sensitivity, density, flow behavior, and other relevant characteristics.
2. Define What Must Happen to the Material
Does the process require turnover, kneading, folding, shear, dispersion, heating, cooling, deaeration, extrusion, or another physical change?
3. Select the Appropriate Mixing Technology
Determine which mixing technology best provides the required behavior.
A Double Arm Mixer may or may not be the appropriate answer.
4. Select the Double Arm Mixer Type
If Double Arm Mixing is appropriate, determine whether the process is better suited for:
Batch Double Arm Mixer
Batch Mixer-Extruder
or
Continuous Mixer-Extruder
5. Engineer the Configuration
Then evaluate application-specific requirements such as blade design, torque, power, drives, shafts, temperature management, discharge, seals, controls, materials of construction, and other process requirements.
Not Sure Which Mixer Term Describes Your Process?
You do not need to know the exact equipment name before talking with Orbis.
Start with the material.
Tell us what you are processing, what needs to happen to it, where your current process is struggling, and what you need production to accomplish.
From there, we can help evaluate the appropriate mixing technology, Double Arm Mixer type, and application-specific configuration.