Wrinkle Smoothing Device for Continuous Sheet Absorbent Articles

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Solution Overview

Problem

Wrinkles form around embossing grooves in continuous sheets during the manufacturing of absorbent articles, leading to appearance issues and potential leakage of body fluids.

Innovation Solution

A wrinkle smoothing device comprising three belts that move along inclined paths to pull the continuous sheet outward, smoothing wrinkles while preventing excessive tensile strength that could damage the sheet.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the embossing protrusion presses against the central portion of the continuous sheet to form a groove-like depression, then the absorbent body is integrated with the continuous sheet, but wrinkles are formed around the groove-like depression

Engineering Contradiction:
Improveintegration of absorbent body with continuous sheetVSAvoidwrinkles around groove-like depression
Core Design Contradiction:
Stability of the object's compositionVSShape

Solution Approach 1:

The pressing operation is divided into two stages: first forming the groove-like depression to integrate the absorbent body, then subsequently smoothing the wrinkles around the depression. This segmentation of the pressing process resolves the contradiction by separating the integration function from the surface quality function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The groove-like depression is formed preliminarily to ensure proper integration of the absorbent body with the continuous sheet before the smoothing operation is applied. This preliminary action ensures that the integration is established first, then the wrinkles are removed without compromising the integration.

Inventive Principle:
Principle #10Preliminary action

2Shape

If the continuous sheet is pulled outward in the width direction to smooth wrinkles, then the appearance is improved, but excessive tensile strength may damage the sheet

Engineering Contradiction:
Improvesmoothing of wrinklesVSAvoidtensile strength applied to continuous sheet
Core Design Contradiction:
ShapeVSStrength

Solution Approach 1:

The smoothing operation applies pulling force partially and progressively rather than excessively. The continuous sheet is pulled outward in the width direction to the extent needed to smooth wrinkles, but the force is controlled to prevent damage. This partial action resolves the contradiction by achieving sufficient smoothing without exceeding the sheet's strength limits.

Inventive Principle:
Principle #16Partial or excessive action

Solution Approach 2:

The pulling force parameters are optimized to achieve wrinkle smoothing while remaining below the damage threshold. By carefully controlling the magnitude and duration of the tensile force applied in the width direction, the sheet is smoothed without being damaged.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If wrinkles remain in the end product, then the manufacturing process is simple, but body fluids may leak along the wrinkles

Engineering Contradiction:
Improvesimplicity of manufacturing processVSAvoidleakage prevention of body fluids
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The manufacturing process is segmented into two distinct operations: integration pressing to form the groove-like depression, and subsequent smoothing to remove wrinkles. This segmentation adds a step to ensure reliability by eliminating leakage paths, while the smoothing operation is efficiently integrated into the existing production line.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The wrinkling that occurs as a side effect of the integration pressing operation is converted into a beneficial smoothing operation. By applying controlled pulling force in the width direction, the wrinkles are transformed from a harmful leakage path into an opportunity to demonstrate process control and improve product reliability.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

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

Effectively smooths wrinkles along the travel direction of the continuous sheet, preventing fluid leakage and maintaining the sheet's integrity.

Implementation Method 1

a first belt that moves along a first travel path while retaining the central portion of the continuous sheet; a second belt that is provided adjacent the first belt on one side in the width direction thereof, and that moves along a second travel path while retaining a portion at the one side from the central portion of the continuous sheet; and a third belt that is provided adjacent the first belt on an other side in the width direction thereof, and that moves along a third travel path while retaining a portion at the other side from the central portion of the continuous sheet

Methodology Applied
Scientific EffectMechanical Force: Mechanical Force

Data Source

PatentEP2623076B1Wrinkle-smoothing method, and wrinkle-smoothing device for continuous-sheet-complex for absorbent article
Publication Date: 2016.09.14 UNI CHARM CORP
  • EP2623076B1 patent drawingFigure 1A~1B
  • EP2623076B1 patent drawingFigure 2
  • EP2623076B1 patent drawingFigure 3

AI summary

A device that smoothes out wrinkles of a composite body of a continuous sheet, in a state a polymeric material is overlapped to a central portion in a width direction of the continuous sheet that travels, to which a depression is shaped at the central portion by a protruding member being pressed against the central portion from the continuous sheet side. The wrinkle smoothing device for a composite body of a continuous sheet related to an absorbent article includes a first belt that moves along a first travel path while retaining the central portion of the continuous sheet; a second belt that is provided adjacent the first belt on one side in the width direction thereof, and moves along a second travel path while retaining a portion at the one side from the central portion of the continuous sheet; and a third belt that is provided adjacent the first belt on an other side in the width direction thereof, and moves along a third travel path while retaining a portion at the other side from the central portion of the continuous sheet, wherein the second travel path is inclined from the first travel path such that a downstream side is more spaced apart from the first travel path to the one side in the width direction than the upstream side, the third travel path is inclined from the first travel path such that a downstream side is spaced more apart from the first travel path to the other side in the width direction than the upstream side, the second belt retains a portion on the one side of the continuous sheet while relatively sliding in the width direction of the continuous sheet, and the third belt retains a portion on the other side of the continuous sheet while relatively sliding in the width direction of the continuous sheet.