Elastic Diaper Component Integrative Pre-Stretching

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Solution Overview

Problem

Conventional elastic diaper components require high fitting forces during application and may over-extend when accommodating waist expansion, potentially causing discomfort and material damage due to aggressive activation methods.

Innovation Solution

Integrative pre-stretching of elastic laminates reduces the fitting force required for diaper application and accommodates waist expansion, while maintaining retraction forces, by stretching the laminate across its width in an amalgamated manner, thereby reducing material stress and extending the range of suitable elastic materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If conventional elastic diaper components are used without pre-stretching, then the component provides sufficient retraction force to maintain snug fit, but the fitting force required during application is excessively high

Engineering Contradiction:

Improvefitting forceVSAvoidease of application

Core Design Contradiction:

ForceVSEase of operation

Solution Approach 1:

The elastic laminate is pre-stretched during manufacturing to a predetermined percentage (e.g., 50-200%) before final assembly. This preliminary action reduces the fitting force required during diaper application by pre-activating the elastic layers, making the component easier to apply while maintaining adequate retraction force.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The pre-stretching process changes the physical state and mechanical properties of the elastic laminate. By controlling the pre-stretch percentage and subsequent relaxation, the elastic characteristics are modified to provide lower fitting force while preserving sufficient retraction force for maintaining snug fit.

Inventive Principle:

Principle #35Parameter changes

2Strength

If aggressive activation methods are used to enhance elastic properties, then the elastic component provides strong retraction force, but the material is prone to damage and tearing

Engineering Contradiction:

Improveretraction forceVSAvoidmaterial integrity

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The elastic laminate undergoes controlled pre-stretching at predetermined percentages during manufacturing, which gradually activates the elastic layers without subjecting them to excessive stress. This preliminary activation provides sufficient retraction force while avoiding material damage and tearing that would occur with aggressive post-activation methods.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The manufacturing process incorporates pre-stretching steps that cushion the activation process, distributing stress evenly throughout the laminate structure. This beforehand cushioning prevents concentration of forces that could lead to material failure, ensuring both strong retraction force and maintained material integrity.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If the elastic laminate is stretched beyond intermediate lengths during fitting, then the component accommodates larger waist expansions, but the sudden increase in resistance causes over-extension and potential material damage

Engineering Contradiction:

Improvewaist accommodation rangeVSAvoidover-extension damage

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The elastic laminate is pre-stretched during manufacturing to establish a baseline elastic state. This preliminary action creates a more gradual resistance curve during subsequent stretching, allowing the component to accommodate waist expansions without sudden resistance spikes that would cause over-extension or material damage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

Pre-stretching modifies the mechanical parameters of the elastic laminate, changing the extension force profile from linear to non-linear with a more gradual increase. This parameter change allows greater adaptability for waist accommodation while reducing the risk of harmful over-extension effects.

Inventive Principle:

Principle #35Parameter changes

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 pre-stretching technique lowers the initial fitting force, prevents over-extension, and allows for a wider range of elastic laminates to be used, enhancing comfort and reducing the risk of material damage during activation.

Implementation Method 1

an elastic laminate which initially has a recoverable extension of at least 20% when stretched at an extension force E1. This elastic laminate is subjected to integrative pre-stretching to thereby allow the elastic laminate to be stretched to the same recoverable extension at a reduced extension force E2

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS8080198B2Elastic diaper component

Publication Date: 2011.12.20 AVERY DENNISON CORP

AI summary

A method of making an elastic component for incorporation into a diaper. The elastic diaper component begins as an elastic laminate (e.g., an elastic layer and a fabric layer) having a recoverable extension of at least 20% when an extension force E1 is applied. The method comprises the step of integratively pre-stretching the elastic laminate so that the elastic laminate will stretch to the same recoverable extension when a reduced extension force E2 is applied. In this manner, when the elastic laminate is used in the elastic diaper component, a lesser fitting force Ffit is required to extend the elastic component to a desired length during an initial fitting of a diaper on a wearer.