Kneader

Kneader

1. Product Overview

1.1 General Description

The kneader is key equipment for mixing, reacting and drying high-viscosity materials in the chemical, food and pharmaceutical industries. Two intermeshing Sigma- or Z-shaped blades rotate in opposite directions at different speeds inside a W-shaped trough, exerting strong compression, shear, folding and stretching on the material to achieve uniform mixing in a short time. A kneader handles viscosities up to several million mPa·s and is a purpose-built mixer that conventional agitators cannot replace. Modern kneaders adopt variable-frequency drives and PLC control to support forward/reverse rotation, vacuum operation and heating/cooling cycles. They are widely used for high-viscosity materials such as silicone rubber, sealants, carbon compounds, battery pastes, food fillings and pharmaceutical ointments.

1.2 Key Features

• Twin Sigma/Z-blade design delivers strong shear and high mixing uniformity
• Blade speed ratio 1:1.2–1:1.5 creates intense compression and folding
• Handles extremely high-viscosity materials (100k–5,000k mPa·s)
• W-shaped trough leaves no dead zone and discharges cleanly
• Variable-frequency drive allows stepless speed adjustment for different materials
• Optional vacuum system down to -0.095 MPa
• Jacketed trough for steam/thermal-oil heating or cooling-water cooling
• Hydraulic trough tilting for easy, clean discharge
• Product-contact parts in SS304/316L stainless steel
• PLC + HMI control stores multiple process recipes

1.3 Document Scope

This specification covers the kneader's design principle, performance parameters, system classification, core component selection, application fields, design standards and certifications, optional custom configurations, warranty terms, packaging and delivery, and the information required for inquiry. It serves as a comprehensive reference for procurement selection and engineering communication.

2. Working Principle

2.1 Kneader Process Flow

Complete workflow: feeding → low-speed pre-mix → high-speed kneading → vacuum de-aeration → temperature-controlled reaction → trough tipping/discharge → cleaning. The two blades rotate in opposite directions at different speeds; on meshing, material is compressed, sheared and folded, and on separating it is stretched and dispersed. The Sigma blade suits medium-viscosity materials, the Z-blade suits ultra-high-viscosity materials. Blade-to-wall clearance is 2–5 mm. Vacuum-type kneaders are fitted with a vacuum system that pulls below -0.095 MPa during mixing to remove air bubbles and volatiles.

3. System Classification

4.1 Main Technical Parameters