Magnesium Hydroxide Deinking Neutralizes Alkaline Brightness Loss

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The conventional alkaline process for deinking secondary fibers is costly, hazardous, and affects fiber quality by causing brightness loss, yellowing, and reduced tensile strength, while also introducing runnability issues in papermaking due to elevated pH and residual adhesive problems.

Innovation Solution

A composition comprising activated magnesium hydroxide, a suspending agent, water, and optionally an emulsifier, excluding caustic soda and hydrogen peroxide, is used to remove ink from cellulosic substrates, improving deinking efficiency and fiber quality without the drawbacks of alkaline methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If conventional alkaline process using caustic soda is used for deinking, then ink removal effectiveness is improved, but fiber brightness is reduced and fiber yellowing occurs

Engineering Contradiction:

Improveink removal effectivenessVSAvoidfiber brightness

Core Design Contradiction:

ProductivityVSIllumination intensity

Solution Approach 1:

The patent changes the chemical parameter from high pH (caustic soda) to neutral pH (magnesium hydroxide suspension), fundamentally altering the deinking mechanism from alkaline swelling to neutral pH detachment, thereby removing brightness loss and yellowing while maintaining ink removal effectiveness

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent replaces expensive caustic chemicals with inexpensive magnesium hydroxide suspension, reducing chemical costs while eliminating the harmful effects of caustic on fiber brightness and strength

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

2Productivity

If conventional alkaline process using caustic soda is used for deinking, then ink removal effectiveness is improved, but fiber tensile strength is reduced

Engineering Contradiction:

Improveink removal effectivenessVSAvoidfiber tensile strength

Core Design Contradiction:

ProductivityVSStrength

Solution Approach 1:

The patent changes the pH parameter from highly alkaline to neutral, eliminating the damaging effect of caustic on fiber strength while maintaining effective ink removal through alternative mechanisms

Inventive Principle:

Principle #35Parameter changes

3Productivity

If conventional alkaline process using caustic soda is used for deinking, then ink removal effectiveness is improved, but handling safety is worsened due to hazards

Engineering Contradiction:

Improveink removal effectivenessVSAvoidhandling safety

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces hazardous caustic chemicals with safe magnesium hydroxide suspension, eliminating handling hazards while maintaining deinking effectiveness

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The patent converts the harmful caustic environment into a safe neutral environment, turning a hazardous process into a safe one while preserving the essential deinking function

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

4Productivity

If conventional alkaline process using caustic soda is used for deinking, then ink removal effectiveness is improved, but chemical cost is increased

Engineering Contradiction:

Improveink removal effectivenessVSAvoidchemical cost

Core Design Contradiction:

ProductivityVSQuantity of substance

Solution Approach 1:

The patent replaces expensive caustic chemicals with inexpensive magnesium hydroxide suspension, significantly reducing chemical costs while maintaining effective ink removal

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

5Productivity

If conventional alkaline process using caustic soda is used for deinking, then ink removal effectiveness is improved, but fiber quality is worsened due to yellowing and brightness loss

Engineering Contradiction:

Improveink removal effectivenessVSAvoidfiber quality

Core Design Contradiction:

ProductivityVSStability of the object's composition

Solution Approach 1:

The patent changes the pH parameter from highly alkaline to neutral, preventing the chemical reactions that cause fiber yellowing and brightness loss while maintaining effective ink removal

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent converts the harmful alkaline environment into a beneficial neutral environment, eliminating fiber degradation while preserving deinking effectiveness

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

6Productivity

If conventional alkaline process using caustic soda is used for deinking, then ink removal effectiveness is improved, but papermaking runnability is worsened due to residual stickies

Engineering Contradiction:

Improveink removal effectivenessVSAvoidpapermaking runnability

Core Design Contradiction:

ProductivityVSEase of operation

Solution Approach 1:

The patent changes the pH from highly alkaline to neutral, preventing saponification of adhesives and eliminating residual stickies that cause papermaking runnability problems

Inventive Principle:

Principle #35Parameter changes

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

The solution effectively reduces residual ink, enhances ISO brightness, maintains fiber whiteness, and improves deinking efficiency while avoiding the hazards and costs associated with alkaline processes, resulting in better optical properties and reduced stickies in the papermaking process.

Implementation Method 1

a suspending agent for said activated magnesium hydroxide

Methodology Applied

Scientific EffectSuspension: Suspension

Implementation Method 2

optionally an emulsifier

Methodology Applied

Scientific EffectEmulsion: Emulsion

Data Source

PatentUS8466204B2Deinking a cellulosic substrate using magnesium hydroxide

Publication Date: 2013.06.18 ECOLAB USA INC

AI summary

The present disclosure is directed to a composition comprising activated magnesium hydroxide, a thickening agent for said magnesium hydroxide, water, an emulsifier, and an oil comprising tall oil fatty acid. In certain embodiments, the composition contains no caustic soda or hydrogen peroxide. The composition comprises from about 5% to about 70% by weight magnesium hydroxide, based upon the weight of the composition. The composition is useful in pulp deinking. In certain embodiments, the thickening agent may be xanthan gum, and the emulsifier may be sodium lauryl sulfate.