Organic Peroxy Acid Brightness Enhancement in Pulp

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Solution Overview

Problem

Current methods for enhancing the brightness and optical properties of paper products using optical brightening agents (OBAs) are not effective when introduced during the size press operation, leading to inefficiencies in component utilization and reaction time.

Innovation Solution

A method involving the use of organic peroxy acid in combination with ammonium salt at pH 4-9, along with optional chelants and oxidizing agents, is applied to bleached pulp material during the papermaking process, particularly in the size press stage, to enhance the response of OBAs and improve brightness without significant bleaching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If optical brightening agents (OBAs) are introduced during the size press operation, then the brightness enhancement should be achieved, but the effectiveness is insufficient due to poor component utilization and inadequate reaction time

Engineering Contradiction:
ImprovebrightnessVSAvoideffectiveness of brightness enhancement
Core Design Contradiction:
Illumination intensityVSProductivity

Solution Approach 1:

The patent applies preliminary action by introducing oxidizing agents and OBAs in a specific sequence during the size press operation. The oxidizing agents are applied first to prepare the pulp surface, followed by OBAs, ensuring that the pulp is in the optimal state for OBA activation. This sequential preliminary preparation maximizes the effectiveness of subsequent brightness enhancement treatments.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent utilizes parameter changes by controlling pH levels (maintaining pH 4-9) and oxidation states during the size press operation. By adjusting these parameters, the patent optimizes the chemical environment for OBA activation and brightness enhancement, transforming the pulp surface properties to improve component utilization and reaction efficiency.

Inventive Principle:
Principle #35Parameter changes

2Illumination intensity

If high doses of OBAs are used to achieve desired brightness, then brightness enhancement is improved, but cost-effectiveness and chemical utilization efficiency deteriorate

Engineering Contradiction:
ImprovebrightnessVSAvoiddose of OBAs
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent changes the chemical environment parameters (pH 4-9, oxidation state) to optimize OBA performance at lower concentrations. By controlling these parameters, the patent enables efficient OBA activation with reduced doses, improving both cost-effectiveness and chemical utilization efficiency while maintaining desired brightness levels.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent introduces oxidizing agents as intermediaries that prepare the pulp surface and enhance OBA activation. These intermediaries facilitate more efficient OBA performance at lower doses by modifying the pulp surface properties and creating optimal conditions for brightening agent effectiveness.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Illumination intensity

If conventional bleaching methods are used to maintain brightness, then brightness is improved, but thermal brightness loss occurs during subsequent papermaking processes

Engineering Contradiction:
ImprovebrightnessVSAvoidbrightness stability
Core Design Contradiction:
Illumination intensityVSStability of the object's composition

Solution Approach 1:

The patent applies preliminary anti-action by using oxidizing agents and OBAs during the size press operation to pre-protect the pulp against subsequent thermal brightness loss. This preliminary treatment creates a stable brightened state that resists degradation during later papermaking processes, counteracting potential brightness deterioration before it occurs.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The patent ensures continuity of useful action by maintaining brightness enhancement effects through the size press operation and into subsequent papermaking processes. The chemical treatments applied during sizing continue to provide brightness protection throughout the manufacturing process, ensuring sustained brightness stability without requiring additional intensive bleaching stages.

Inventive Principle:
Principle #20Continuity of useful 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 increased brightness and whiteness of paper products with reduced doses of OBAs, offering improved efficiency and cost-effectiveness by ensuring all chemicals react efficiently with the pulp, and protecting against thermal brightness loss.

Implementation Method 1

contacting the paper sheet with an effective amount of an organic peroxy acid in a mixture with ammonium salt at pH 4-9

Methodology Applied
Scientific EffectOxidation: Oxidation

Implementation Method 2

enhancing brightness and optical properties of a paper product in presence of optical brightening agents (OBA)

Methodology Applied
Scientific EffectFluorescence: Fluorescence

Data Source

PatentUS9068293B2Method for improving brightness in bleached pulp
Publication Date: 2015.06.30 NALCO CO

AI summary

The invention is directed towards methods and compositions for processes based on the combination of organic peroxyacids and ammonium salts that preserve and enhance the response to optical brighteners (fluorescent whitening dyes), brightness and improve color of pulp or paper when applied during different stages of the papermaking process are identified. The composition and method improve response to optical brighteners (fluorescent whitening dyes), maintain and/or enhance brightness and enhance the performance of paper products. Used in combination with optical brighteners the described agents produce a synergistic effect not previously identified in the paper process.