Stacked Air-Permeable Member Plates for Absorbent Article Manufacturing

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Solution Overview

Problem

The existing air-permeable members used in absorbent article manufacturing face issues with durability due to fatigue failure and clogging when increasing the efficiency of pulp fiber deposition, primarily because of the limitations in hole shape and arrangement, which affect the aperture ratio and strength.

Innovation Solution

The solution involves stacking plates with uniformly shaped air holes that communicate across the thickness direction, joined by diffusion welding, to enhance rigidity and prevent clogging, while maintaining a high aperture ratio through etching for dense air hole arrangements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If the aperture ratio of the air-permeable member is increased by decreasing the distances between air holes, then the deposition efficiency of pulp fibers is improved, but the strength of portions between air holes decreases and fatigue failure occurs

Engineering Contradiction:
Improvedeposition efficiencyVSAvoidstrength between air holes
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The air-permeable member is divided into multiple plates stacked in the thickness direction. Each plate contains air holes, and the stacking creates a multi-layer structure where portions between air holes in different plates overlap and are joined together, distributing the stress and preventing fatigue failure while maintaining high aperture ratio

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The solution transitions from a single-plane air hole arrangement to a three-dimensional stacked plate structure. By adding the thickness direction as an additional dimension, the design achieves high aperture ratio through dense in-plane arrangement while gaining structural strength through inter-plate joining of the portions between air holes

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If the hole diameter of air holes is increased to improve air flow rate, then the deposition efficiency is improved, but the restriction on pulp fiber passage is reduced

Engineering Contradiction:
Improveair flow rateVSAvoidpulp fiber passage control
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The air flow path is segmented into multiple plates stacked in series. Each plate maintains small hole diameters (0.1-1 mm) that restrict pulp fiber passage, while the cumulative effect of multiple plates provides sufficient total air flow rate for efficient deposition

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If tapered holes are formed by etching method, then the manufacturing process is simplified, but the holes are likely to be clogged during deposition

Engineering Contradiction:
Improvemanufacturing processVSAvoidclogging
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The air-permeable member is segmented into multiple plates with small thickness (0.05-0.5 mm each). This segmentation allows the use of etching method to create substantially straight-sided holes without significant tapering, as the etching depth is limited by the small plate thickness, thereby preventing clogging while maintaining manufacturing simplicity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The plate thickness parameter is reduced to 0.05-0.5 mm, which changes the etching process outcome from highly tapered to substantially straight-sided holes. This parameter change eliminates clogging while preserving the ease of manufacture through etching

Inventive Principle:
Principle #35Parameter changes

4Strength

If the thickness of the air-permeable member is increased to improve strength, then the fatigue resistance is improved, but the etching method produces highly tapered holes that are difficult to manufacture

Engineering Contradiction:
Improvefatigue resistanceVSAvoidhole shape control
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

Instead of increasing the thickness of a single plate, the structure is segmented into multiple thin plates (0.05-0.5 mm each) stacked together. This provides the necessary strength and fatigue resistance through the multi-plate construction while keeping individual plate thickness small enough to allow etching of substantially straight-sided holes

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

This approach improves the durability and prevents clogging by ensuring straight-sided air holes and increased joining strength between plates, enhancing the air-permeable member's rigidity and deposition efficiency.

Implementation Method 1

an air-permeable member 50 having as its main body an appropriate plate material, and a plurality of air holes 50h are formed through the plate material in a thickness direction, thereby giving air permeability to the air-permeable member 50

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

an etching method is preferable as the method that can closely form the foregoing minute holes having a diameter of 0.1 to 1 mm

Methodology Applied
Scientific EffectEtching:

Implementation Method 3

each of which includes a joining portion for joining to an adjacent plate in the thickness direction in a portion of the plate in which the air holes are not formed

Methodology Applied
Scientific EffectDiffusion welding: Diffusion Welding

Data Source

PatentEP2612634B1Device for manufacturing absorber and method for manufacturing air permeable member
Publication Date: 2017.08.09 UNI CHARM CORP
  • EP2612634B1 patent drawingFigure 1
  • EP2612634B1 patent drawingFigure 2A~2B
  • EP2612634B1 patent drawingFigure 3A~3B

AI summary

An apparatus for manufacturing an absorbent body of an absorbent article by depositing a liquid absorbent material on an air-permeable member by passing an air that contains the liquid absorbent material in a thickness direction of the air-permeable member, the apparatus including: a plurality of plates that are stacked in the thickness direction, that constitutes the air-permeable member, each of which includes a plurality of air holes that penetrate the plate in the thickness direction and that allow the air to pass, and each of which includes a joining portion for joining to an adjacent plate in the thickness direction in a portion of the plate in which the air holes are not formed, the plurality of air holes of each of the plates being arranged so as to communicate with corresponding air holes of an adjacent plate in the thickness direction, corresponding air holes of all the plates stacked in the thickness direction having a same shape.