Acrylic Latex Sealant Sigma Mixer

An Acrylic Latex Sealant Sigma Mixer (also known as a Sigma Blade Kneader) is a specialized industrial mixing machine designed for processing high-viscosity, sticky, or dough-like materials. It features two counter-rotating Z-shaped (sigma) blades within a trough-like chamber, which provide thorough kneading, shearing, and folding action to achieve uniform blending. This equipment is commonly used in chemical, pharmaceutical, food, and adhesive manufacturing industries for its ability to handle tough-to-mix formulations without introducing excessive heat or air.

Acrylic Latex Sealant Sigma Mixer Video

Key Features and Specifications

• Design: Double sigma blades rotate at differential speeds for optimal shear and dispersion. The mixer often includes a jacketed vessel for heating/cooling, vacuum ports for de-aeration, and discharge options like hydraulic tilting or screw extruders.

• Capacity: Ranges from lab-scale  to production-scale, depending on the model.

• Materials: Constructed from stainless steel for corrosion resistance, suitable for food-grade or chemical applications.

• Power and Speed: Motor power varies; blade speeds around 30-50 RPM.

• Safety: Includes interlocking lids, overload protection, and variable frequency drives for speed control.

Applications in Acrylic Latex Sealant Production

Sigma Mixers are particularly effective for manufacturing acrylic latex sealants, which are water-based, paintable caulks used for sealing gaps in construction, windows, doors, and joints. These sealants offer flexibility, UV resistance, and adhesion to substrates like wood, metal, and masonry. The mixer’s kneading action excels at incorporating fillers (e.g., calcium carbonate), thickeners, pigments, and silicone modifiers into the viscous latex base, ensuring homogeneity and preventing clumping.

• Process Overview:

  1. Charge the vessel with acrylic latex emulsion, surfactants, and dispersants.

  2. Add fillers and pigments in stages while mixing at controlled temperatures (e.g., <40°C to avoid coagulation).

  3. Knead under vacuum to remove air bubbles, achieving a smooth, thixotropic paste.

  4. Discharge the batch for packaging (e.g., into 10 oz cartridges).

This method improves properties like wet adhesion, elongation (up to 300%), and durability in wet conditions, as seen in formulations with polysiloxane additives.

Advantages for Acrylic Latex Sealant Mixing

• Efficiency: Handles viscosities up to 5 million cps, reducing mixing time by 30-50% compared to planetary mixers.

• Versatility: Also used for similar products like silicone rubber, butyl sealants, inks, and cosmetics.

• Quality: Minimizes degradation of sensitive latex polymers, resulting in sealants that cure to a flexible, water-tight seal with primerless adhesion.

Design of Sigma Mixer

Sigma Mixers design offered as per different application requirements. We offer wide range of design features meeting various user requirements. Some of the features are listed below:

• Blade Material: Material option of AISI 1030, AISI CF8 & AISI CF8M

• U Trough: Construction gauge offered from 3mm thick up to 30mm thick in mild steel and stainless steel 304 & 316 options.

• Motor horsepower: Motor horsepower ranging from 1.5 H.P. up to 250 H.P power.

• Power Voltage: Can be design as per various geographical power voltage requirements.

• Rotation speed: Fix and variable speed RPM offered with option of variable frequency drive.

• Feeding: Manual type feeding as well as vacuum/screw type automatic feeding can be offered.

• Discharge: Manual, chain type and hydraulic type automatic tilting as well as screw type side discharge system.

• Heating: Heating jacket offered for steam heating, hot water circulation and electrical heaters with suitable grade insulation.

• Cooling: Jacket offered for cool water circulation.

• Sealing: Silicon & PTFE sealing for food grade and asbestos sealing for industrial grade equipment offered.

• Finish: 180 grits to 240 grit finish on stainless steel parts and epoxy paint on mild steel parts.

• Discharge Clearance: Discharge clearance can be offered as per user requirements.

Salient Features of Sigma Mixer Machine

• Available in Stainless Steel 316, Stainless Steel 304 and Mild Steel materials.

• Stainless Steel polish to matt & mirror finish as per customer’s requirements.

• Mild Steel finish with one coat of red oxide and two coats of epoxy paint.

• Discharge option of hand wheel operated (manual) or hydraulic operated (automatic) offered.

• Jacket for heating or cooling application can be offered.

• Mineral wool insulation with cladding on jacket.

• Tangential designed ‘Z’ blades offered for uniform mixing.

• PTFE made shaft sealing provided for food grade compatibility.

• Minimum gap between trough inner shell & blades removes possibility of sticking product.

• On demand Spray system, vacuum system

Optional Features/Accessories of Sigma Mixer

• Liquid Spray System

• Vacuum System

• Blades Cooling Arrangement

• Screw System

• Automatic Valve Discharge System

Process Operation of Sigma Mixer Machine

In Sigma mixer tangential action of mixing and kneading obtained by ‘Z’ type (SIGMA) shaped kneading blades, which rotates very accurately at different speed towards each other causing product to be transferred from one end to another end. Discharge of the finished product is achieved by tilting the container or through the valves at the bottom or by means of an extrusion screw beside the container.

The mixing action is a combination of bulk movement, stretching, folding, dividing, and recombining of the material. The shearing & tearing action of the material against blades and the side walls causes size reduction of the solids. After the time period required for sterilizing the batch has elapsed, the heating circuit shuts of the pneumatics damper (exhaust) opens and cooling operation commences.

In the tangential design, the blades rotate in the trough meeting tangentially. The front blade generally rotates faster than the rear blade usually in the ratio of 3:2. Tangential blades are generally used for material of higher viscosities such as adhesives, rubber compounds, flush colors, dyes, and pigments.

In the overlapping design, the blades overlap above the saddle of the container. Due to the overlapping action, it is necessary that the relative position of the two blades is unchanged, and as a result, both the blades rotate at the same speed. Materials that flow freely or creep down into the blades are mixed using the overlapping blade action. This design offers a faster interchange of material from one blade compartment of the mixer to the other. Overlapping blade action is used for materials of lighter viscosities such as carbon pastes, clay coating, creams, and ointments. The overlapping blade produces a lower kneading and shearing compared to the tangential blade action.

Technical Specification of Sigma Mixer 

* Power voltage can be adjusted as per customer’s domestic power voltage requirements.
* Rights of technical improvements & modification reserved.
* Illustrations & dimensions are shown for information purpose only.