Cationic Polyetheramine Dispersant for Papermaking Fiber Dispersion

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing papermaking technologies face challenges in dispersing long cellulosic fibers, particularly hydrophilic fibers like hemp and solvent-regenerated fibers, which tend to entangle and form flocs or nits, leading to suboptimal paper quality and increased viscosity in papermaking stock.

Innovation Solution

A cationic polyetheramine dispersant is developed, comprising a polyether diamine, polyether bisepoxide, and quaternary ammonium salt, which reacts in specific molar ratios to associate with fiber surfaces, reducing steric repulsion and preventing fiber entanglement during stock preparation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If conventional mechanical agitation is used to disperse fibers, then some dispersion is achieved, but fiber entanglement and nit formation persist especially with hydrophilic fibers

Engineering Contradiction:

Improvefiber dispersion stabilityVSAvoidfiber entanglement and nit formation

Core Design Contradiction:

Stability of the object's compositionVSObject-generated harmful factors

Solution Approach 1:

A cationic polyetheramine dispersant is introduced as an intermediary substance between water and cellulosic fibers. The dispersant contains cationic charges that electrostatically interact with negatively charged fiber surfaces, creating a steric and electrostatic barrier that prevents fiber entanglement and nit formation during stock preparation and storage.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The invention changes the chemical parameter of the dispersing medium by introducing a polyetheramine dispersant with specific molecular weight, charge density, and hydrophilic-lipophilic balance. This chemical modification allows effective dispersion of hydrophilic fibers without requiring excessive mechanical energy input.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If high mechanical energy input is applied to disperse fibers, then fiber dispersion improves, but energy consumption and processing cost increase

Engineering Contradiction:

Improvefiber dispersion uniformityVSAvoidmechanical energy for dispersion

Core Design Contradiction:

Stability of the object's compositionVSUse of energy by moving object

Solution Approach 1:

The invention replaces part of the mechanical dispersion system with a chemical dispersion system. Instead of relying solely on high-shear mixers and refiners to separate fibers, a cationic polyetheramine dispersant is used to provide electrostatic repulsion and steric hindrance, reducing the need for intensive mechanical processing.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-generated harmful factors

If dispersing aids are added to improve fiber dispersion, then fiber entanglement reduces, but slurry viscosity increases dramatically

Engineering Contradiction:

Improvefiber flocs and nitsVSAvoidslurry viscosity

Core Design Contradiction:

Object-generated harmful factorsVSForce

Solution Approach 1:

The dispersant is designed with specific molecular parameters including controlled molecular weight (affecting chain length and steric bulk), charge density (affecting electrostatic repulsion strength), and hydrophilic-lipophilic balance (affecting water interaction). By optimizing these parameters, the dispersant provides effective fiber separation without causing excessive viscosity increase.

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 cationic polyetheramine dispersant effectively reduces fiber flocs and nits, improving the uniformity and quality of paper products while maintaining low viscosity in the fiber slurry, as demonstrated by improved handsheet formation and reduced fines generation during refining.

Implementation Method 1

the cationic polyetheramines of the invention are especially useful to disperse relatively long cellulosic papermaking fibers

Methodology Applied

Scientific EffectElectrostatic interaction: Electrostatics

Implementation Method 2

Without intending to being bound by theory, it is believed that the cationic polyetheramine dispersants of the invention function by associating with the fiber surfaces thereby setting up steric repulsion between neighboring fibers during stock preparation

Methodology Applied

Scientific EffectSteric repulsion:

Data Source

PatentUS10662586B2Cationic polyetheramine dispersants for preparing papermaking stock

Publication Date: 2020.05.26 GPCP IP HOLDINGS LLC

AI summary

A cationic polyether amine dispersant for papermaking fibers comprises the polymeric reaction product of a polyether diamine, a polyether bisepoxide and a quaternary ammonium salt. The polyether diamine, the polyether bisepoxide and the quaternary ammonium salt reactants are reacted in the following molar ratios: the molar ratio of amine functionality of the polyether diamine to epoxide functionality of the polyether bisepoxide is from 0.5:1 to 2:1 and the molar ratio of the amine functionality of the polyether diamine to the epoxide functionality of the quaternary ammonium salt is from 10:1 to 40:1. The dispersant is used in stock preparation used in paper products including absorbent products as well as paperboard.