Laminated Absorbent Structure With High Absorbency at Low Basis Weight

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Solution Overview

Problem

Conventional absorbent structures, such as disposable paper towels and wipes, face challenges in achieving high absorbency while maintaining low basis weight, which is essential for cost-effectiveness and environmental sustainability.

Innovation Solution

The development of a laminate structure comprising at least two plies with specific surface features, including a Valley Volume greater than 11 microns and a Pit Density of greater than 25 pockets per square centimeter, achieved through a wet-laid structured tissue process using cellulosic-based and synthetic fibers, with embossing and a water-soluble adhesive for enhanced absorbency and strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional water-laid or air-laid technologies are used to produce absorbent structures, then manufacturing ease and production speed are improved, but absorbency is reduced due to web compaction during pressing

Engineering Contradiction:

Improvemanufacturing easeVSAvoidabsorbency

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent employs a porous forming fabric with controlled pore structure to create void spaces within the web during the forming process. This porous structure allows the web to maintain high void volume and absorbency without requiring intensive pressing, thus resolving the contradiction between ease of manufacture and absorbency retention.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent changes the physical parameters of the forming process by controlling the solids content, pressing intensity, and forming fabric characteristics to achieve optimal web structure. By adjusting these parameters, the web maintains sufficient porosity for high absorbency while still allowing efficient water removal during manufacturing.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If more material is used to increase absorbency, then absorbency is improved, but basis weight increases leading to higher cost and reduced environmental sustainability

Engineering Contradiction:

ImproveabsorbencyVSAvoidbasis weight

Core Design Contradiction:

ReliabilityVSQuantity of substance

Solution Approach 1:

The use of porous forming fabric creates a web with enhanced void volume that increases absorbency without requiring additional material. The porous structure provides more space for liquid absorption, allowing high absorbency performance at lower basis weight.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent introduces a third dimension by creating vertical void spaces and surface topography variations through the porous forming fabric. This dimensional approach increases the effective absorption capacity without increasing the planar area or material quantity, thus achieving high absorbency at low basis weight.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Use of energy by moving object

If web pressing is intensified to remove more water during manufacturing, then energy consumption is reduced, but web thickness and absorbency are compromised

Engineering Contradiction:

Improveenergy consumptionVSAvoidabsorbency

Core Design Contradiction:

Use of energy by moving objectVSReliability

Solution Approach 1:

The porous forming fabric enables efficient water removal through its pore structure during the forming process, reducing the need for intensive mechanical pressing. This allows moderate pressing intensity that preserves web thickness and absorbency while still achieving effective dewatering.

Inventive Principle:

Principle #31Porous materials

Solution Approach 2:

The patent utilizes the hydraulic properties of the porous forming fabric to facilitate water drainage through capillary action and pressure gradients during the forming process. This hydraulic approach enables efficient water removal without requiring high mechanical pressing forces, thus preserving web structure and absorbency.

Inventive Principle:

Principle #29Pneumatics and hydraulics

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 allows for high absorbency exceeding 16 grams of water per gram of fiber at a basis weight of less than 43 grams per square meter, reducing the need for costly materials and conserving natural resources, while maintaining strength and performance.

Implementation Method 1

forming a nascent web in a forming structure

Methodology Applied

Scientific EffectFiltration: Filter (physical)

Implementation Method 2

transferred to a dewatering felt where it is pressed to remove moisture

Methodology Applied

Scientific EffectCapillary action: Capillary Action

Implementation Method 3

transferred to a dewatering felt where it is pressed to remove moisture

Methodology Applied

Scientific EffectAbsorption: Absorption (physical)

Implementation Method 4

a water-soluble adhesive for enhanced absorbency and strength

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS12037748B2Method of making absorbent structures with high absorbency and low basis weight

Publication Date: 2024.07.16 FIRST QUALITY TISSUE LLC

AI summary

Absorbent product including a laminate of at least two plies, wherein the absorbent product has a measured Valley Volume parameter greater than 11 microns and a Pit Density of greater than 25 pockets per sq·cm.