Why Choose a Sigma Mixer for UK & EU Production?

A sigma mixer—also known as a double-arm kneader—is the preferred solution for processing high-viscosity, cohesive, and non-free-flowing materials that conventional mixers simply cannot handle. In UK and EU manufacturing environments, sigma mixers are widely used where shear, compression, and controlled heat transfer are essential to product quality.

Sigma mixers excel at processing materials such as doughs, pastes, putties, gums, polymers, adhesives, sealants, battery slurries, pharmaceutical masses, and specialty chemicals. Their distinctive Z- or sigma-shaped blades rotate at differential speeds, continuously folding, stretching, and compressing the product to achieve uniformity—even at extremely high viscosities.

For regulated UK and EU industries, sigma mixers offer critical advantages:

They provide exceptional torque and mechanical strength, allowing consistent mixing of materials that would stall or overload other mixer types. Their enclosed trough design enables precise temperature control through heating and cooling jackets, supporting processes such as melting, plasticising, solvent reduction, or thermal activation.

Sigma mixers are also well suited to vacuum operation, enabling deaeration, moisture removal, and solvent control in a single vessel. This is especially valuable in pharmaceutical, chemical, and battery manufacturing, where oxidation control and product consistency are tightly regulated.

From a compliance standpoint, modern sigma mixers can be engineered with hygienic or industrial-grade construction, smooth internal finishes, sealed bearings, and robust safety interlocks. Systems supplied for the UK and EU can be built with UKCA and CE marking and configured to ATEX standards, supporting safe operation under DSEAR requirements.

In short, a sigma mixer is chosen when the process demands power, control, repeatability, and reliability—not just mixing, but true material transformation. For manufacturers facing difficult formulations, rising quality expectations, or stricter regulatory oversight, sigma mixers remain one of the most proven and versatile solutions in modern production.

Twin Shaft Kneading

Two counter-rotating sigma blades knead, fold, and shear the material.
Provides intensive mixing for high-viscosity pastes and slurries.

Sealing & Containment

All seals are isolated from the product zone.
Options: mechanical seals, stuffing boxes with purge, or gas-sealed designs for ATEX zones.

Thermal Control & Vacuum Options

Jacketed troughs allow heating/cooling via steam, water, or thermal oil.
Vacuum options enable deaeration or drying during mixing.

Feeding & Discharge

Feed via top ports, hoppers, or vacuum loading.
Discharge via tilting troughs, bottom valves, or screw/ram extruders for viscous materials.

Loading — viscous material charged into chamber
Kneading Action — sigma blades fold, shear, and compress material repeatedly
Thermal Regulation — jacketed surfaces maintain target temperature
Vacuum/Inerting — volatile removal or inert atmosphere if required
Discharge — through valves, tilt, or screw/ram discharge systems

Side Screw Kneader-Extruder

Provides positive discharge of highly viscous, non-flowing products
Single or twin screw, with zoned heating/cooling
Torque & head-pressure monitoring for precise control
Vacuum venting and inert gas purging possible
Die plate options for strand, sheet, or pellet forms

Hydraulic Discharge Press (Ram)

Batch discharge option for extremely stiff doughs or pastes
Hydraulic ram forces product out through sanitary valves or dies
Ideal for adhesives, gum bases, or high-solids pharmaceutical pastes

When to Choose

Extruder: continuous discharge, downstream forming, mass-flow control
Hydraulic press: intermittent batches, very stiff compounds

Heavy-duty frame & shafts for extreme torque
Custom sigma blade geometries (serrated, scraper, kneading profiles)
Heating/cooling jackets with multi-zone control
Vacuum/inert systems for moisture & oxygen control
Advanced instrumentation (torque, temp, vacuum sensors)
PLC/HMI with recipe management
ATEX/DSEAR compliant builds for hazardous areas
Material options: 304/316L stainless, Hastelloy, Titanium, Duplex
Easy cleaning: CIP, removable covers, inspection ports

Adhesives & Sealants: resins, mastics, fillers
Food: doughs, confectionery pastes, thick sauces
Pharmaceuticals: APIs, wet granulations, viscous pastes
Cosmetics: creams, gels, pastes
Specialty Chemicals: composites, catalysts, ceramic pastes

Example: A UK sealant producer uses a sigma kneader-extruder with vacuum venting to blend filled polymer pastes and extrude them directly into cartridges under ATEX compliance.

Handles materials standard mixers cannot process
Vacuum + thermal control in one vessel
Optional extrusion for continuous, sealed discharge
Lower contamination risk: seals kept out of product zone
Local UK engineering support, validation, and servicing
Regulatory confidence: UKCA, CE, GMP, ATEX/DSEAR

To define the right build, consider:

Batch size & throughput goals
Material rheology and viscosity range
Heating/cooling requirements
Moisture or solvent removal needs
Material compatibility (abrasive/corrosive)
Cleaning & GMP validation demands
Discharge type: tilt, valve, screw, or hydraulic press

When your process demands high-torque kneading of viscous pastes, doughs, or slurries, the PerMix Sigma Mixer UK is the proven solution.

Contact PerMix UK with your process details — viscosity, solids content, batch goals, temperature needs — and we’ll configure the right mixer, with optional kneader-extruder or discharge press, to meet your UK/EU standards.

PerMix Sigma Mixer