Cellulose Fiber Mixer Compression Treatment

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Solution Overview

Problem

Existing paper manufacturing processes face issues such as clogging of fabrics, altered drainability, increased energy consumption, reduced production speed, and generation of non-recoverable waste due to the presence of fine cellulosic elements and shear-induced fiber cutting during refining.

Innovation Solution

A method involving mechanical compression and chemical modification of cellulose fibers in an aqueous suspension using a mixer with specific mixing elements and controlled shear, minimizing shear forces while enhancing fiber flexibility and bonding potential.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If traditional refiner-type machine with high speed differential is used, then fiber bonding surface is increased, but fine elements and cut fibers are generated causing clogging and reduced productivity

Engineering Contradiction:
Improvefiber bonding surfaceVSAvoidproduction speed
Core Design Contradiction:
StrengthVSProductivity

Solution Approach 1:

The patent replaces the traditional high-speed differential refiner mechanical system with a low-speed differential system combining mechanical compression and chemical modification. The mixer uses compression forces rather than shear forces to achieve fiber bonding, substituting the conventional refiner mechanism with a chemically-assisted mechanical system that avoids fine element generation while maintaining bonding effectiveness.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent fundamentally changes the operating parameters by reducing the speed differential from 20-25 m/s to less than 15 m/s, and primarily using compression forces instead of shear forces. This parameter change transforms the fiber treatment mechanism from shear-based refinement to compression-based modification, eliminating the generation of fine elements and cut fibers while achieving the desired fiber bonding.

Inventive Principle:
Principle #35Parameter changes

2Strength

If intense refining is applied, then paper mechanical properties are improved, but energy consumption increases significantly

Engineering Contradiction:
Improvemechanical properties of paperVSAvoidenergy consumption
Core Design Contradiction:
StrengthVSUse of energy by moving object

Solution Approach 1:

The patent introduces chemical reagents as intermediaries to assist the mechanical compression process. The chemical modification works synergistically with the mechanical compression to achieve fiber bonding and improve paper mechanical properties, reducing the need for intense mechanical refining and thereby lowering energy consumption while maintaining or enhancing paper strength.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Strength

If chemical modification is performed in conventional reactor, then fiber properties are improved, but process time and energy consumption increase

Engineering Contradiction:
Improvefiber propertiesVSAvoidprocess time
Core Design Contradiction:
StrengthVSLoss of time

Solution Approach 1:

The patent merges the mechanical compression process and chemical modification process into a single integrated mixer operation. Both processes occur simultaneously in the same equipment and time frame, eliminating the need for separate processing stages. This combination achieves fiber property improvement while significantly reducing total process time and associated energy consumption compared to conventional sequential reactor-based chemical modification.

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Reduces the generation of fine elements and cut fibers, improves fiber binding and mechanical properties, enhances paper quality, and promotes environmental sustainability by minimizing waste and energy consumption.

Implementation Method 1

mechanical compression and chemical modification of the cellulose fibers (2), in aqueous suspension... the compression surfaces of the mixing elements face the compression surface of the mixing enclosure, so as to define between said respective compression surfaces compression zones of the suspension of fibers circulating between the body and the mixing axis

Methodology Applied
Scientific EffectMechanical compression: Compression

Implementation Method 2

in the presence of a chemical reagent to produce an aqueous composition of cellulose fibers having chemically modified functional groups

Methodology Applied
Scientific EffectChemical modification: Chemical Vapour Deposition

Implementation Method 3

The invention aims to provide such a method which does not generate shear, or at least so little that it becomes negligible... the method having a speed differential between the at least one mixing axis and the mixing enclosure of less than or equal to 15 m/s

Methodology Applied
Scientific EffectShear force reduction: Shear Stress

Data Source

PatentEP4575078A1Method for the mechanical and chemical treatment of cellulose fibres in a mixer
Publication Date: 2025.06.25 CENT TECH DU PAPIER
  • EP4575078A1 patent drawingFigure 1
  • EP4575078A1 patent drawingFigure 2~3
  • EP4575078A1 patent drawingFigure 4~6

AI summary

The present invention relates to a method for the mechanical and chemical treatment of cellulose fibers in aqueous suspension in a mixer (1) comprising a body (10) defining a mixing chamber (11) whose wall forms a fixed compression surface (12), and at least one mixing axis (20) positioned in the mixing chamber (11) and comprising a rotatable shaft (21), and a plurality of mixing elements (22) fixed on the shaft (21), projecting radially from the shaft, and each provided with a rotatable compression surface (23). In said method, the compression surfaces (23) of the mixing elements (22) face the compression surface (12) of the mixing chamber (11), so as to define between them compression zones (ZC) of the fiber suspension (2) circulating between the body (10) and the mixing axis (20).The compression surfaces (23) of the mixing elements (22) have a compression profile whose radius relative to the shaft (21) varies according to the angular position of said shaft, so as to compress the suspension of fibers (2) in said compression zones (ZC) during the rotation of said mixing axis (20).