Non-woven Tampon Cover Using Continuous Filaments

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Solution Overview

Problem

Existing nonwoven material coverings for tampons, particularly those made of staple fibers, suffer from exposed fiber ends that increase roughness and lead to increased fiber loss, reducing wearing comfort and mechanical stability.

Innovation Solution

A nonwoven cover using multi-component continuous filaments with thermoplastic heat-sealable materials, where the filaments are pressed together in specific areas and remain unconnected in others, providing low friction and high elasticity without surface smoothing, and utilizing a combination of polymers with different melting points to enhance strength and prevent fiber separation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If staple fibers are used to make nonwoven coverings, then the material can be manufactured with defined cutting length, but exposed fiber ends increase roughness and reduce wearing comfort

Engineering Contradiction:
Improvemanufacturing processVSAvoidwearing comfort
Core Design Contradiction:
Ease of manufactureVSEase of operation

Solution Approach 1:

The patent changes the fundamental parameter from staple fibers to continuous filaments, eliminating the exposed fiber ends problem while maintaining manufacturability. This parameter change transforms the surface morphology from rough with exposed ends to smooth with continuous surfaces, directly resolving the contradiction between ease of manufacture and wearing comfort

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs multi-component filaments with different materials (e.g., hydrophilic and hydrophobic components) to create a composite structure. This allows the outer surface to provide low friction and smoothness while the inner structure maintains strength and absorbency, resolving the contradiction between comfort and manufacturing properties

Inventive Principle:
Principle #40Composite materials

2Ease of operation

If surface smoothing is applied to reduce friction coefficients, then static friction decreases, but pore sizes are reduced due to fiber flattening and fusing

Engineering Contradiction:
Improvefriction coefficientVSAvoidpore size
Core Design Contradiction:
Ease of operationVSQuantity of substance

Solution Approach 1:

The patent changes the surface morphology parameter by using continuous filaments with inherent smooth surfaces rather than smoothing processed staple fibers. This approach reduces friction through the fundamental surface geometry of the filaments themselves while preserving pore structure, as the smooth surface is achieved through filament selection rather than compression

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses the natural smooth surface geometry of continuous filaments as a template, eliminating the need for mechanical smoothing processes. The filaments are arranged and bonded in a way that copies the desirable smooth surface characteristics without the harmful side effects of pore reduction

Inventive Principle:
Principle #26Copying

3Ease of operation

If continuous filaments are used instead of staple fibers, then fiber ends are eliminated improving smoothness, but thermal bonding may cause filament separation and exposed ends

Engineering Contradiction:
Improvesurface smoothnessVSAvoidfiber stability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The patent uses multi-component filaments where different materials are bonded together through thermal bonding. The composite structure allows controlled bonding at specific points while maintaining the integrity of the continuous filaments, preventing separation and exposed ends while preserving surface smoothness

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies thermal bonding locally at specific points rather than uniformly across the entire fabric. This localized bonding approach secures the continuous filaments in place, preventing separation and exposed ends, while leaving other areas unbonded to maintain surface smoothness and porosity

Inventive Principle:
Principle #3Local quality

4Ease of operation

If the entire filament surface is formed by low-friction polymer to reduce friction, then friction coefficient decreases, but fiber strength and wetting behavior deteriorate

Engineering Contradiction:
Improvefriction coefficientVSAvoidfiber strength
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The patent uses multi-component filaments where different materials are distributed along the filament surface. This allows specific segments to provide low friction while other segments provide strength and wetting properties, resolving the contradiction between friction reduction and fiber performance

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent applies different material properties to different locations on the filament surface. Low-friction polymer is applied only where needed for surface contact, while other segments maintain strength and wetting characteristics, creating a functionally optimized filament structure

Inventive Principle:
Principle #3Local quality

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 solution results in a smooth, high-strength, and elastic nonwoven fabric with reduced fiber loss and improved wetting behavior, maintaining low friction and preventing fiber ends, thus enhancing the overall performance and comfort of tampons.

Implementation Method 1

the continuous filaments are pressed together in first areas and fixed by thermal bonding while melting the thermoplastic heat-sealable material

Methodology Applied
Scientific EffectMelting: Melting

Implementation Method 2

the various components of the filaments, or in the case of more than two components, at least two of the components also each form parts of the outer surface of the filaments

Methodology Applied
Scientific EffectPhase change: Phase Change

Data Source

PatentEP1988202B1Non-woven fabric cover with low friction coefficients for feminine hygiene, in particular for tampons or for medical purposes, and articles equipped with same
Publication Date: 2012.12.05 CARL FREUDENBERG KG
  • EP1988202B1 patent drawingFigure 1~2
  • EP1988202B1 patent drawingFigure 3
  • EP1988202B1 patent drawingFigure 4

AI summary

A non-woven covering has (1) at least one layer of endless multicomponent filaments (3) with at least one heat-sealable thermoplastic component, pressed together and fixed by thermal bonding in first regions (5) and not fixed in second regions (7) between the bonded regions.