Fibrous Superabsorbent Composite Using Carboxyalkyl Cellulose

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Solution Overview

Problem

Current personal care absorbent products, such as diapers and incontinent pads, face inefficiencies due to the non-biodegradability and high cost of acrylic acid-based superabsorbent polymers, as well as the tendency of cellulose-based fibrous matrices to release liquid under pressure, leading to skin wetness and leakage.

Innovation Solution

A fibrous superabsorbent composite is created by blending carboxyalkyl cellulose with galactomannan or glucomannan polymers, crosslinking, and combining with cellulose fibers, followed by treatment with crosslinking agents and a water-miscible solvent, resulting in a water-insoluble yet highly absorptive material.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If acrylic acid-based superabsorbent polymers are used, then absorbency is improved, but cost increases and biodegradability is lost

Engineering Contradiction:

ImproveabsorbencyVSAvoidcost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent changes the chemical composition parameters by using carboxymethyl cellulose (a cellulose derivative) instead of acrylic acid-based polymers. This substitution maintains the superabsorbent functionality while using a biodegradable, renewable resource that is less expensive and environmentally friendly.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite material system combining carboxymethyl cellulose with crosslinking agents (such as borax, aluminum salts, or zinc salts) to achieve the desired absorbency properties. This composite approach allows the material to exhibit superabsorbent behavior comparable to synthetic polymers while maintaining biodegradability.

Inventive Principle:

Principle #40Composite materials

2Stability of the object's composition

If cellulose-based fibrous matrices are used, then biodegradability is improved, but liquid retention is worsened due to liquid release under pressure

Engineering Contradiction:

ImprovebiodegradabilityVSAvoidliquid retention

Core Design Contradiction:

Stability of the object's compositionVSReliability

Solution Approach 1:

The patent modifies the physical and chemical parameters of cellulose by derivatizing it to carboxymethyl cellulose and crosslinking it with metal salts or borax. These parameter changes transform the material from a simple fibrous matrix that releases liquid into a gel-forming superabsorbent material that retains liquid even under pressure.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent utilizes phase transition by forming a gel structure from the carboxymethyl cellulose-crosslinking agent system. This gel phase allows the material to absorb and retain large amounts of liquid while maintaining structural integrity, preventing the liquid release problem associated with conventional cellulose fibers.

Inventive Principle:

Principle #36Phase transitions

3Reliability

If high gel strength is designed, then absorbency under load is improved, but void volume increases leading to interstitial liquid and poor wet feeling

Engineering Contradiction:

Improveabsorbency under loadVSAvoidvoid volume

Core Design Contradiction:

ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent optimizes the crosslinking degree and gel structure parameters to achieve high absorbency under load without excessive void volume. By controlling the crosslinking agent concentration and type, the material achieves a balanced gel structure that provides both mechanical strength and efficient liquid distribution.

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 fibrous composite achieves improved absorbency, reduced leakage, and enhanced skin comfort by maintaining liquid retention while being biodegradable and cost-effective, suitable for various personal care and industrial applications.

Implementation Method 1

blending a carboxyalkyl cellulose and either a galactomannan polymer or glucomannan polymer in water to provide an aqueous solution

Methodology Applied

Scientific EffectHydrophilic interaction: Hydrophile

Implementation Method 2

treating the aqueous solution with a first crosslinking agent to provide a gel

Methodology Applied

Scientific EffectCrosslinking: Chemical Bonding

Implementation Method 3

The fibrous composite achieves improved absorbency, reduced leakage, and enhanced skin comfort by maintaining liquid retention while being biodegradable

Methodology Applied

Scientific EffectGel swelling: Gel

Data Source

PatentUS7625463B2Methods for the preparation of fibrous superabsorbent composite containing cellulose

Publication Date: 2009.12.01 GCF US HOLDINGS LLC

AI summary

A method for making a fibrous composite, comprising blending a carboxyalkyl cellulose and a galactomannan polymer or a glucomannan polymer in water to provide an aqueous solution; treating the aqueous solution with a first crosslinking agent to provide a gel; drying the gel to provide a solid; comminuting the solid to provide a plurality of particles; combining at least a portion of the plurality of particles with an aqueous suspension comprising cellulose treated with a galactomannan polymer or a glucomannan polymer, and optionally a second crosslinking agent, to provide a mixture; and mixing the mixture with a water-miscible solvent to provide a fibrous composite.