Stretchable Laminate Rigid Lane Holding Ability

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Solution Overview

Problem

Existing stretchable laminates used in sanitary articles, such as diapers, lack sufficient holding ability when stretched and bonded to another material, leading to deformation or peeling, and do not provide an optimal touch sensation for users.

Innovation Solution

A stretchable laminate with an elastomer layer and a non-woven fabric layer, featuring an elastic lane portion and a rigid lane portion, where the rigid lane portion has a specific strength range for 5% deformation and is bonded with a hot-melt pressure-sensitive adhesive containing an olefin-based polymer, enhancing holding ability and touch sensation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the stretchable laminate uses a conventional adhesive bonding structure, then the manufacturing process is simple, but the holding ability is insufficient when stretched

Engineering Contradiction:
Improveholding abilityVSAvoidlaminate structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The laminate is divided into distinct elastic lane portions and rigid lane portions with different structural characteristics. The rigid lane portion has a specific strength range (1-7 N/20 mm for 5% deformation) to provide holding ability, while the elastic lane portion provides stretchability. This segmentation allows each region to be optimized for its specific function.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different regions of the laminate are given different mechanical properties. The rigid lane portion contains olefin-based polymer adhesive with specific strength characteristics for holding, while the elastic lane portion has different adhesive properties for flexibility. This local differentiation resolves the contradiction by providing both holding ability and stretchability in appropriate locations.

Inventive Principle:
Principle #3Local quality

2Reliability

If the rigid lane portion has high strength for holding ability, then the holding ability improves, but the feeling of touch deteriorates

Engineering Contradiction:
Improveholding abilityVSAvoidfeeling of touch
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The laminate structure provides rigid lane portions with high strength (1-7 N/20 mm) for holding ability at specific locations, while other regions maintain softer characteristics for comfortable touch sensation. This localized differentiation allows the rigid portions to provide holding power without making the entire laminate uncomfortable against the skin.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

By segmenting the laminate into rigid and elastic regions, the patent concentrates the high-strength characteristics only where needed for holding (at the rigid lane portions), while allowing other areas to remain soft and comfortable for user contact, thus resolving the contradiction between holding ability and touch sensation.

Inventive Principle:
Principle #1Segmentation

3Strength

If the elastomer layer and non-woven fabric layer are bonded with adhesive, then the bonding is achieved, but deformation or peeling occurs when stretched

Engineering Contradiction:
Improvebonding strengthVSAvoidstructural stability when stretched
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The laminate is segmented into rigid lane portions with strong bonding characteristics (olefin-based polymer adhesive with specific strength) and elastic lane portions with flexibility. This segmentation allows the bonding to be strong where needed while maintaining overall structural stability during stretching through the compliant elastic regions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses a composite structure combining elastomer layers, non-woven fabric layers, and olefin-based polymer adhesive in specific configurations. The rigid lane portions use olefin-based polymer for strong bonding, while the overall composite structure accommodates stretching through the elastic components, preventing peeling while maintaining bonding strength.

Inventive Principle:
Principle #40Composite materials

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 laminate achieves improved holding ability when stretched and bonded, while providing a comfortable touch sensation, making it suitable for use in sanitary articles like diapers.

Implementation Method 1

the elastomer layer and the non-woven fabric layer are generally bonded onto each other with an adhesive or a pressure-sensitive adhesive

Methodology Applied
Scientific EffectAdhesion: Adhesive

Implementation Method 2

the rigid lane portion requiring a strength of from 1 N/20 mm to 7 N/20 mm for obtaining a 5% deformation amount

Methodology Applied
Scientific EffectRigidity:

Implementation Method 3

a stretchable laminate including an elastomer layer and a non-woven fabric layer arranged on at least one side of the elastomer layer

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3078489B1Elastic laminate and article containing same
Publication Date: 2022.02.23 NITTO DENKO CORP
  • EP3078489B1 patent drawingFigure 1
  • EP3078489B1 patent drawingFigure 2
  • EP3078489B1 patent drawingFigure 3

AI summary

Provided is a stretchable laminate which has a sufficient holding ability in the case of being stretched to be bonded onto another material and is excellent in feeling of touch. Also provided is an article including such stretchable laminate. The stretchable laminate of the present invention is a'stretchable laminate, including: an elastomer layer; and a non-woven fabric layer arranged on at least one side of the elastomer layer, the stretchable laminate including an elastic lane portion and a rigid lane portion, the rigid lane portion requiring a strength of from 1 N/20 mm to 7 N/20 mm for obtaining a 5% deformation amount.