Views: 0 Author: Site Editor Publish Time: 2025-10-24 Origin: Site
The Sigma Mixer, also widely known as a Z Blade Mixer or Double Arm Kneader, is a heavy-duty industrial mixing machine specifically designed for processing highly viscous pastes, doughs, rubbers, and semi-solid materials that resist flow.
The heart of the equipment lies in its two unique "Sigma" (Sigma shaped) or "Z"-shaped mixing blades housed in a horizontal trough. These blades rotate toward each other at different speeds (a typical ratio is 3:2 or 1.5:1). This differential speed and specialized shape generate an intense combination of shearing, kneading, and folding actions, essential for achieving uniform mixing in challenging materials.
The exceptional efficiency of the Sigma Mixer for high-viscosity materials stems from its mechanical design:
Differential Speed Rotation: The two blades rotate at different speeds, maximizing the material interchange and creating areas of high and low shear force.
Kneading and Shearing: As the blades rotate, they continuously pick up, stretch, and divide the material, forcing it down into the "saddle" (the central ridge between the two troughs).
Intense Homogenization: The close tolerance between the blades and the trough walls, coupled with the action between the two blades, generates extremely high shear forces. This action rapidly reduces particle size, breaks down agglomerates, and ensures that all components are thoroughly dispersed and homogenized without creating any "dead spots."
This continuous "fold-shear-stretch-divide" cycle is crucial for handling materials like sticky adhesives or high-density battery pastes.
The versatility and power of the Sigma Mixer make it a staple across several industries where high-viscosity material processing is mandatory:
| Industry | Common Applications | Key Benefit |
| Food & Confectionery | Chewing gum base, bubble gum, stiff bread dough, cookie dough, liquorice, marzipan. | Ensures uniform texture and consistency in high-solids mixtures. |
| Chemical & Adhesives | Hot-melt adhesives, epoxy resins, sealants, heavy printing inks, mastics, pigments, ceramic materials. | Achieves complete dispersion and strong bonding of components. |
| Pharmaceutical | Wet granulation for tablets, highly concentrated medicated ointments, gels, and creams. | Meets stringent cleanliness standards (often using Stainless Steel 316L) and homogeneity requirements. |
| New Materials | Silicone rubber, butyl rubber, lithium-ion battery pastes (anode/cathode slurries), carbon products. | Handles high solid content and high-density materials effectively. |
Choosing the right machine for your process is critical. Here are the main factors to consider before investing:
Viscosity and Application Type: This determines the required Motor Power and the optimal blade design (e.g., Tangential or Overlapping blades). Tangential blades are better for higher shear and kneading (like rubber), while Overlapping blades are better for lighter pastes.
Capacity (Total vs. Working): Always specify the batch size. Working capacity is typically $40\%$ to $65\%$ of the total volume.
Temperature Control: If your material requires heating or cooling (e.g., for polymerization or temperature-sensitive mixing), ensure the machine is equipped with a Jacket (for steam, thermal oil, or cooling water).
Vacuum Function: For processes involving volatile solvents or materials that must be mixed under inert gas/vacuum to prevent oxidation or contamination, a Vacuum Kneader is necessary.
Discharge Method:
Tilting Discharge: The most common method, where the bowl is hydraulically tilted for product removal.
Screw Extrusion: Ideal for extremely stiff materials that cannot be poured, where an internal screw forces the product out through a die.
The Sigma Mixer remains the gold standard for mixing materials with high resistance to flow. Its robust design and powerful kneading action guarantee process reliability, superior quality, and highly consistent end-products across the food, chemical, and new energy sectors.
Ready to optimize your high-viscosity mixing process? Contact our experts today to discuss the perfect Sigma Mixer solution tailored to your specific production needs!
frank@karvil.com