Laminated Sheet With Ultrafine Adhesion Layer for Skin Fit

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Solution Overview

Problem

Conventional skin care sheets, such as facial masks, face irritation and have poor adhesion to the skin, leading to peeling or slipping off, and struggle with balancing liquid retention and release, which affects user comfort and satisfaction.

Innovation Solution

A laminated facial mask sheet with a liquid-retention layer and an adhesion layer, where the adhesion layer is formed on one side of the liquid-retention layer, using fibers with specific diameter distributions and materials like polyester, polyolefin, and poly(vinyl alcohol) fibers, to enhance skin adhesion and comfort.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If a spunlace nonwoven fabric comprising a cellulose-series fiber is used as a nonwoven fabric sheet for impregnation with a cosmetic preparation, then the sheet has high liquid retentivity, but it causes irritation to the skin and has insufficient fitting property to the skin

Engineering Contradiction:
Improveliquid retentivityVSAvoidskin irritation
Core Design Contradiction:
Quantity of substanceVSObject-affected harmful factors

Solution Approach 1:

The sheet is divided into multiple functional layers: a liquid-retention layer (nonwoven fabric) and an ultrafine fiber layer. Each layer performs a specific function - the nonwoven fabric retains liquid while the ultrafine fiber layer contacts the skin to prevent irritation and improve fitting property.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the sheet have different properties: the inner layer uses cellulose-series fibers for high liquid retentivity, while the outer ultrafine fiber layer provides skin-friendly contact and improved fitting property. This local differentiation resolves the contradiction between liquid retention and skin comfort.

Inventive Principle:
Principle #3Local quality

2Quantity of substance

If the sheet is impregnated with cosmetic preparation to achieve efficacy on the skin, then the liquid retentivity is improved, but the adhesion to the skin becomes insufficient causing peeling or slipping off

Engineering Contradiction:
Improveliquid retentivityVSAvoidadhesion to skin
Core Design Contradiction:
Quantity of substanceVSReliability

Solution Approach 1:

The sheet structure separates liquid retention function (nonwoven fabric layer) from adhesion function (ultrafine fiber layer). The ultrafine fibers create strong adhesion to the skin surface, preventing peeling or slipping even when the sheet is impregnated with cosmetic preparation.

Inventive Principle:
Principle #1Segmentation

3Ease of manufacture

If a nonwoven fabric is produced by splitting a splittable conjugate fiber, then the manufacturing cost is reduced, but it is difficult to obtain uniformly and moderately entangled fibers resulting in low adhesion to the skin

Engineering Contradiction:
Improvemanufacturing costVSAvoidadhesion to skin
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention changes the fiber diameter parameter to ultrafine scale (1-10 μm) and controls the coefficient of fluctuation to 50% or less. This parameter optimization achieves both uniform fiber entanglement for high adhesion and cost-effective manufacturing through efficient fiber utilization.

Inventive Principle:
Principle #35Parameter changes

4Duration of action of moving object

If the sheet is used for a long time to allow cosmetic preparation to permeate into the skin, then the efficacy is improved, but the sheet peels off or slips off due to low adhesion

Engineering Contradiction:
Improveduration of applicationVSAvoidadhesion to skin
Core Design Contradiction:
Duration of action of moving objectVSReliability

Solution Approach 1:

The ultrafine fiber layer is specifically designed to provide long-lasting adhesion to the skin, allowing the sheet to remain in place for extended periods during cosmetic treatment while preventing irritation through its fine fiber structure.

Inventive Principle:
Principle #1Segmentation

5Reliability

If the sheet requires higher adhesion for long-lasting application, then the reliability is improved, but the complexity of the sheet structure increases

Engineering Contradiction:
Improveadhesion to skinVSAvoidsheet structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The sheet uses a simple two-layer segmented structure: a liquid-retention layer and an ultrafine fiber layer. This minimal segmentation achieves high adhesion and skin comfort without excessive structural complexity.

Inventive Principle:
Principle #1Segmentation

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 laminated sheet achieves balanced liquid retentivity and releasability, improved skin adhesion, and reduced irritation, ensuring a comfortable and long-lasting application without peeling or slipping, enhancing user satisfaction and commercial value.

Implementation Method 1

a liquid-retention layer having an ability to absorb a liquid component

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

a liquid-retention layer having an ability to absorb a liquid component (a liquid compound or composition)

Methodology Applied
Scientific EffectAdsorption: Adsorption

Implementation Method 3

an adhesion layer contactable with a skin, wherein the adhesion layer is formed on one side of the liquid-retention layer and is permeable to the liquid component

Methodology Applied
Scientific EffectPermeation: Permeation

Data Source

PatentEP2453047B8Laminated sheet and process for production thereof
Publication Date: 2019.11.20 KURARAY KURAFLEX CO LTD

AI summary

A laminated sheet is produced by forming an adhesion layer permeable to a liquid component and contactable with a skin on at least one side of a liquid-retention layer comprising a nonwoven structural member and having an ability to absorb the liquid component. The adhesion layer comprises a nonwoven structural member comprising a fiber having a number-average fiber diameter of not more than 10 µm, and the thickness ratio of the adhesion layer relative to the liquid-retention layer is 1/4 to 1/100 as a ratio of the adhesion layer/the liquid-retention layer. The fiber of the nonwoven structural member of the adhesion layer may have a standard deviation of fiber diameter of not more than 5. The nonwoven structural member of the liquid-retention layer may comprise a fiber having a fiber diameter larger than that of the fiber of the adhesion layer. The laminated sheet has a liquid retentivity and a liquid releasability in a well-balanced manner, and has an excellent adhesion and an excellent fit to the skin in the state where the sheet is impregnated with a liquid component.