Extensible Disposal Tape for Pull-On Diaper Roll Retention

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Solution Overview

Problem

Existing pull-on disposable diapers face challenges with disposal tape length, as it may not extend sufficiently to maintain the rolled shape of the diaper without exceeding the maximum breaking elongation, leading to potential breakage during disposal.

Innovation Solution

A pull-on disposable diaper design featuring a disposal tape with a fixing part, an extensible part, and an attachment part, arranged in a Z-fold configuration, where the extensible part can extend by a small tensile force to increase length without breaking, and the attachment part can be positioned anywhere on the diaper to maintain the rolled shape.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the disposal tape is simply folded in three without extensibility, then the structure is simple, but the length is insufficient to maintain the rolled shape of the diaper

Engineering Contradiction:
Improvedisposal tape lengthVSAvoiddisposal tape structure
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The disposal tape incorporates an extensible part that changes its physical parameter (length) through elastic deformation. When the diaper is rolled for disposal, the extensible part stretches to provide sufficient length to reach from the rear portion to the front portion, maintaining the rolled shape. This resolves the contradiction by dynamically changing the tape length parameter rather than using a fixed long tape that would increase structural complexity.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The disposal tape transitions from a static folded structure to a dynamic extensible structure. The extensible part allows the tape to adapt its length based on the disposal needs, stretching when required and remaining compact when not in use. This dynamic characteristic resolves the contradiction between needing long tape for disposal and maintaining simple structure during normal wear.

Inventive Principle:
Principle #15Dynamics

2Reliability

If the disposal tape is made excessively extensible to maintain rolled shape, then the disposal function is improved, but the tape may exceed maximum breaking elongation and break

Engineering Contradiction:
Improvedisposal tape reliabilityVSAvoiddisposal tape breaking strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The disposal tape is divided into three distinct parts: a fixing part, an extensible part, and an attachment part. The extensible part is specifically designed with controlled elastic properties to stretch within safe limits, while the fixing and attachment parts maintain higher strength to prevent breakage. This segmentation allows different portions to have optimized properties, resolving the contradiction between needing extensibility and maintaining strength.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The extensible part is designed with specific elastic parameters that allow controlled stretching within the maximum breaking elongation limit. The material and structural parameters are optimized to provide sufficient extensibility for maintaining the rolled shape while staying below the breaking point, thus resolving the contradiction between reliability through extensibility and strength against breakage.

Inventive Principle:
Principle #35Parameter changes

3Adaptability or versatility

If the disposal tape is fixed at a specific position, then the structure is simple, but the length may be insufficient depending on the fixing position

Engineering Contradiction:
Improvedisposal tape positioning flexibilityVSAvoiddisposal tape configuration
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The disposal tape with its extensible part can adapt to different fixing positions dynamically. Whether fixed at the upper rear portion or lower rear portion of the diaper, the extensible part stretches to provide the necessary length to reach the front portion and maintain the rolled shape. This adaptability resolves the contradiction without requiring multiple pre-configured tape options.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The disposal tape is designed to function universally at various fixing positions on the diaper. The extensible part ensures that regardless of where the tape is fixed on the rear portion, it can always extend sufficiently to maintain the rolled shape, making the disposal mechanism versatile and position-independent without increasing structural complexity.

Inventive Principle:
Principle #6Universality (Multi-functionality)

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 design enhances the disposal process by allowing the disposal tape to extend significantly while preventing breakage, ensuring easy and effective maintenance of the diaper's rolled shape during disposal, improving operational ease and reliability.

Implementation Method 1

an extensible part (15), and an attachment part (18)... the extensible part can extend by a small tensile force to increase length without breaking

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3666239B1Underpants-type disposable diaper
Publication Date: 2023.04.26 KAO CORP
  • EP3666239B1 patent drawingFigure 1~2
  • EP3666239B1 patent drawingFigure 3~4

AI summary

A diaper (1) includes, on an outer surface, a disposal tape (10). The disposal tape (10) includes a fixing part (12), an extensible part (15), and an attachment part (18) in sequence in the longitudinal direction (X1) of the disposal tape (10) and is folded in three stacked in the sequence. The attachment part (18) and the extensible part (15) are releasably joined, and the extensible part (15) and the fixing part (12) are also releasably joined. The attachment part (18) starts to extend at a tensile strength higher than the tensile strength at which the extensible part (15) starts to extend. The tensile strength at which the extensible part (15) starts to extend is 6.5 N or less. The peel strength between the attachment part (18) and the extensible part (15) is 4.0 N or less.