Nanocellulose Gel Dosing via High Shear Fluidization

Solution Overview

Problem

The challenge in industrial applications is to achieve even distribution and efficient usage of microfibrillated cellulose (MFC) in papermaking and related processes, as conventional methods require extensive dilution, leading to uneven suspension quality and high water usage, which is economically and technically challenging, especially when dealing with high solid content gels that form strong self-assemblies and flocculation.

Innovation Solution

A method involving the nanocellulose suspension in gel phase is subjected to a high shear rate of more than 500 1/s, fluidizing the gel before being added to a second suspension, ensuring even mixing and distribution, particularly in papermaking, coating compositions, and surface sizing, thereby improving the strength and retention of fibers and chemicals.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If MFC is diluted to achieve even distribution, then distribution uniformity is improved, but water consumption increases and solid content decreases

Engineering Contradiction:

Improvedistribution uniformityVSAvoidwater consumption

Core Design Contradiction:

Manufacturing precisionVSQuantity of substance

Solution Approach 1:

The patent applies preliminary action by subjecting the MFC suspension to high shear rate treatment (more than 500 1/s) before dosing it into the second suspension. This pre-shearing breaks up agglomerates and ensures uniform distribution is achieved without requiring excessive dilution with water, thus resolving the contradiction between distribution uniformity and water consumption.

Inventive Principle:

Principle #10Preliminary action

2Productivity

If MFC is dosed at high solid content, then productivity is improved, but suspension quality becomes uneven and gel particles form

Engineering Contradiction:

Improvedosage efficiencyVSAvoidsuspension quality

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent applies preliminary action by subjecting the MFC suspension to high shear rate treatment (more than 500 1/s) before dosing it into the second suspension. This pre-shearing breaks up agglomerates and ensures uniform distribution is achieved without requiring excessive dilution with water, thus resolving the contradiction between distribution uniformity and water consumption.

Inventive Principle:

Principle #10Preliminary action

3Strength

If MFC forms strong gels, then bonding strength is improved, but accessibility to chemicals is reduced

Engineering Contradiction:

Improvebonding strengthVSAvoidchemical accessibility

Core Design Contradiction:

StrengthVSObject-generated harmful factors

Solution Approach 1:

The patent applies preliminary action by subjecting the MFC suspension to high shear rate treatment (more than 500 1/s) before dosing it into the second suspension. This pre-shearing breaks up agglomerates and ensures uniform distribution is achieved without requiring excessive dilution with water, thus resolving the contradiction between distribution uniformity and water consumption.

Inventive Principle:

Principle #10Preliminary action

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

This approach results in improved strength and even distribution of nanocellulose in products like paper and paperboard, enhanced retention of fibers and chemicals, and reduced re-flocculation, allowing for efficient dosing at high solid contents without the need for excessive water, thus overcoming the limitations of conventional methods.

Implementation Method 1

the nanocellulose suspension in gel phase is subjected to a shear rate of more than 500 1/s, immediately prior to the step of bringing said nanocellulose suspension in gel phase and said second suspension in contact with each other

Methodology Applied

Scientific EffectShear rate: Shear Stress

Data Source

PatentEP3649286B1Dosing of nanocellulose suspension in gel phase

Publication Date: 2024.04.24 STORA ENSO OYJ

AI summary

A method of dosing a nanocellulose suspension in gel phase into a second suspension, wherein the method comprises the steps of: providing said nanocellulose suspension in gel phase; providing said second suspension; bringing said nanocellulose suspension in gel phase in contact with said second suspension;wherein the method comprises a step of subjecting said nanocellulose suspension in gel phase to a shear rate of more than 500 1/s, simultaneously with and/or immediately prior to the step of bringing said nanocellulose suspension in gel phase and said second suspension in contact with each other.