Absorbent Article Leak-Proof Wall Welding Pattern Optimization

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Solution Overview

Problem

Conventional absorbent articles with leak-proof walls face issues of texture degradation and poor fit due to excessive strength and overlapping welded parts, particularly when using nonwoven fabrics pre-embossed with welded parts, which can lead to leakage and discomfort.

Innovation Solution

The absorbent article features leak-proof walls with a sheet member overlaid in the thickness direction, where the second welded parts have a smaller area than the first welded parts, reducing the likelihood of overlap and maintaining sufficient welding strength, thus preventing texture degradation and peeling, and ensuring a stable fit by arranging second welded parts with a smaller area ratio in the central region for reduced rigidity at the groin area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If many welded parts are formed all over the sheet member to increase the strength of the leak-proof wall, then the strength is improved, but the texture and fit are degraded

Engineering Contradiction:
Improvestrength of leak-proof wallVSAvoidtexture and fit
Core Design Contradiction:
StrengthVSEase of operation

Solution Approach 1:

The patent applies local quality by differentiating the welding density in different regions of the leak-proof wall. The central region (groin area) has a lower welding area ratio (5-20%) compared to the end regions (30-50%), providing localized optimization where the central region maintains flexibility and texture while end regions provide structural strength.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the sheet member is made of pre-embossed nonwoven fabric, then the texture is improved, but the texture is further degraded when embossed parts overlap with welded parts

Engineering Contradiction:
ImprovetextureVSAvoidtexture degradation at overlap
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The patent implements local quality control by restricting welded parts to specific regions that avoid overlapping with pre-existing embossed patterns on the nonwoven fabric. The welding area ratio is controlled to be 5-20% in the central region and 30-50% in end regions, ensuring welded parts are positioned where they will not degrade the embossed texture.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent applies preliminary action by pre-defining the positioning and area ratios of welded parts before the welding process. The welding pattern is planned in advance to avoid overlap with embossed regions, preventing texture degradation before it occurs.

Inventive Principle:
Principle #10Preliminary action

3Strength

If second welded parts have large area, then welding strength is sufficient, but overlap with first welded parts increases causing texture degradation

Engineering Contradiction:
Improvewelding strengthVSAvoidtexture degradation
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The patent applies local quality by varying the area ratio of second welded parts based on location. In the central region where texture is critical, the welding area ratio is limited to 5-20%. In end regions where structural strength is more important, the welding area ratio can be increased to 30-50%.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses partial action by providing welding only in specific regions rather than uniformly across the entire leak-proof wall. This selective welding approach provides sufficient strength where needed while avoiding texture degradation in critical areas.

Inventive Principle:
Principle #16Partial or excessive 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 design effectively suppresses texture degradation and peeling of the leak-proof walls, maintaining a stable fit and preventing leakage by optimizing the welding strength and distribution of welded parts, ensuring a smoother and more comfortable wear.

Implementation Method 1

an elastic member stretching/contracting in the longitudinal direction

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

the sheet member is welded (embossed) at a plurality of positions

Methodology Applied
Scientific EffectWelding: Welding

Data Source

PatentEP3485860B1Absorbent article
Publication Date: 2020.05.27 UNI CHARM CORP
  • EP3485860B1 patent drawingFigure 1
  • EP3485860B1 patent drawingFigure 2
  • EP3485860B1 patent drawingFigure 3A~3B

AI summary

An absorbent article includes: an absorbent body (11) having a longitudinal direction and a lateral direction orthogonal to each other; and a pair of leak-proof walls (50) provided on both lateral sides of the absorbent body (11). Each of the leak-proof walls is formed of a sheet member (50s) including a plurality of first welded parts (61) on a surface of the sheet member (50s). And, each of the leak-proof walls (50) includes an overlaid part (50L) where the sheet member (50s) is overlaid in a thickness direction such that an elastic member (52) stretching/contracting in the longitudinal direction is sandwiched. In at least a part of a region of the overlaid part (50L), a plurality of second welded parts (62) that join the overlaid sheet member (50s) is disposed. An area of the second welded parts (62) is smaller than an area of the first welded parts (61).