Thin Absorbent Articles Using Open-Cell Foam for Shape Stability

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing absorbent articles face challenges in being both thin and flexible while maintaining shape and high absorbency, particularly under compressive forces, leading to issues like buckling and reduced fluid absorption rates.

Innovation Solution

The development of an absorbent article with a caliper expansion of at least 150% featuring a heterogeneous mass layer comprising enrobeable elements and discrete open-cell foam pieces, which enhances fluid absorption and maintains shape stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the absorbent article is made thinner to improve flexibility and garment-like fit, then flexibility and comfort are improved, but the fluid storage volume and absorbency are reduced

Engineering Contradiction:
ImproveflexibilityVSAvoidfluid storage volume
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent utilizes open-cell foam pieces with high porosity to achieve high fluid storage capacity within a thin profile. The porous structure allows rapid fluid uptake while maintaining a compressed state that fits within thin article constraints, resolving the contradiction between thinness and fluid storage volume.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent combines multiple materials including open-cell foam pieces, superabsorbent polymers, and fibrous materials in a composite absorbent core structure. This composite approach enables the thin article to achieve high absorbency by leveraging the complementary properties of each material within the constrained thickness.

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If the absorbent article is made thinner to improve flexibility, then flexibility is improved, but shape retention under compressive forces deteriorates

Engineering Contradiction:
ImproveflexibilityVSAvoidshape retention
Core Design Contradiction:
Ease of operationVSShape

Solution Approach 1:

The patent employs a thin, flexible backsheet and topsheet construction that maintains garment-like conformability while incorporating structural elements within the absorbent core that resist buckling. The flexible layers adapt to body movement while the internal foam structure provides shape stability.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The open-cell foam pieces have a three-dimensional cellular structure that provides inherent structural integrity and resistance to compressive forces. The curved, cellular geometry of the foam pieces helps maintain article shape while allowing flexibility at the macro level.

Inventive Principle:
Principle #14Spheroidality (Curvature)

3Quantity of substance

If thicker products are used to increase fluid storage volume, then absorbency is improved, but the product tends to buckle and lose shape stability under bodily compressive forces

Engineering Contradiction:
Improvefluid storage volumeVSAvoidshape stability
Core Design Contradiction:
Quantity of substanceVSShape

Solution Approach 1:

The open-cell foam pieces provide a porous structure that absorbs fluid while maintaining structural integrity. The cellular architecture allows the material to expand with fluid uptake without buckling, maintaining shape stability even as fluid storage volume increases.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The composite absorbent core combining foam pieces with superabsorbent polymers and fibrous materials creates a structurally stable assembly that resists buckling under compression while providing high fluid storage capacity, eliminating the shape instability problem of thicker products.

Inventive Principle:
Principle #40Composite materials

4Speed

If faster superabsorbent polymers are used to increase absorption speed, then absorption rate is improved, but the materials are more dense and require bulky acquisition volumes which increase thickness

Engineering Contradiction:
Improveabsorption speedVSAvoidthickness
Core Design Contradiction:
SpeedVSLength of stationary object

Solution Approach 1:

The open-cell foam pieces provide a highly porous acquisition layer that rapidly takes in fluid through capillary action and surface area exposure. This porous structure achieves fast absorption without the density and bulkiness of conventional superabsorbent polymers, maintaining thin article profile.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The absorbent core is segmented into discrete open-cell foam pieces rather than using a continuous bulk material. This segmentation increases surface area for fluid uptake, accelerating absorption speed while keeping each piece compact and the overall article thin.

Inventive Principle:
Principle #1Segmentation

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 allows for high absorbency and shape retention, even when loaded, ensuring continuous use without noticeable bulges or reduced absorption rates, providing a comfortable and effective absorbent experience.

Implementation Method 1

The upper layer is a heterogeneous mass layer comprising a longitudinal axis, a lateral axis, a vertical axis, one or more enrobeable elements, and discrete open-cell foam pieces

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

high capacity to absorb fluids and are particularly effective in absorbing these fluids in a quick manner

Methodology Applied
Scientific EffectAbsorption: Absorption (physical)

Implementation Method 3

the absorbent article has a caliper expansion, measured at one minute according to the dynamic caliper expansion test described herein, of at least 150%

Methodology Applied
Scientific EffectCaliper expansion: Thermal Expansion

Implementation Method 4

the panty is no longer able to provide sufficient recovery force (via elastics and material stretch during motion) to unbuckle the plastically deformed shape and to return the product to the desired shape

Methodology Applied
Scientific EffectElastic recovery: Elasticity

Data Source

PatentEP3370666B1Thin and flexible absorbent articles
Publication Date: 2022.09.28 PROCTER & GAMBLE CO
  • EP3370666B1 patent drawingFigure 1
  • EP3370666B1 patent drawingFigure 2
  • EP3370666B1 patent drawingFigure 3

AI summary

The present invention relates to an absorbent article, comprising a fluid permeable topsheet, a backsheet and an absorbent element disposed between the topsheet and the backsheet wherein the absorbent article has a caliper expansion, measured at 1 minute of at least 150%. The present invention also relates to an absorbent article, comprising a fluid permeable topsheet, a backsheet and an absorbent element disposed between the topsheet and the backsheet wherein the absorbent article has a ratio of dry caliper to the caliper expansion measured at 1 minute of 3 mm/% or less.