Molding Sheet with Partial Resin Infiltration

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Solution Overview

Problem

Existing sheets for molding are limited in their versatility and durability for various applications, often experiencing breakage during molding processing and lacking in properties like moisture barrier, water barrier, and electromagnetic wave shielding.

Innovation Solution

A sheet for molding comprising a nonwoven fabric with fibers having a specific birefringence range and a resin layer with a defined molecular weight range, where the resin partially infiltrates and partially does not infiltrate the nonwoven fabric, enhancing durability and allowing for additional properties like electromagnetic wave shielding when filled with appropriate materials.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conventional spunbonded nonwoven fabric is used for thermoforming, then it can provide basic molding functionality, but it experiences breakage during molding processing and lacks durability

Engineering Contradiction:
ImprovedurabilityVSAvoidbreakage resistance
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The invention uses a composite structure consisting of a nonwoven fabric layer and a resin layer. The nonwoven fabric provides the base structure while the resin layer (containing polyester resin, acrylic resin, and/or polyurethane resin) enhances durability and prevents breakage during molding. This composite material approach resolves the contradiction by combining materials with complementary properties.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The resin layer is applied to specific regions of the nonwoven fabric where enhanced strength and durability are needed. The resin infiltrates the nonwoven fabric structure locally, providing targeted reinforcement without altering the entire material structure, thus improving breakage resistance while maintaining the base functionality.

Inventive Principle:
Principle #3Local quality

2Adaptability or versatility

If a conventional sheet for molding is used, then it can be molded into basic shapes, but it lacks versatility for various applications such as moisture barrier, water barrier, and electromagnetic wave shielding

Engineering Contradiction:
Improveapplication rangeVSAvoidstructure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The resin layer serves multiple functions simultaneously: it provides moisture barrier, water barrier, electromagnetic wave shielding, and sound absorption properties. By incorporating functional fillers into the resin layer, a single material structure can achieve multiple performance requirements, enhancing versatility without proportionally increasing complexity.

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

Solution Approach 2:

The properties of the resin layer can be adjusted by changing the resin composition, molecular weight, and filler content. This allows the same basic structure to be adapted for different applications by modifying material parameters rather than redesigning the entire structure, thus improving versatility while controlling complexity.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the resin layer fully infiltrates the nonwoven fabric, then it enhances durability, but it loses the ability to provide surface properties and barrier functions

Engineering Contradiction:
ImprovedurabilityVSAvoidmoisture barrier, water barrier
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The resin layer is positioned and infiltrated to specific degrees in different regions. The surface portion maintains its barrier properties by not being fully infiltrated, while the underlying portions provide durability through resin reinforcement. This local differentiation resolves the contradiction between durability and barrier functionality.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The resin layer is structured with different infiltration depths creating a multi-level structure. The superficial layer remains intact for barrier functions while deeper infiltration provides structural reinforcement. This dimensional approach allows simultaneous achievement of durability and barrier properties.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 provides a sheet for molding that is easily used across various applications, preventing breakage and imparting properties such as moisture barrier, water barrier, and durability, while allowing for the inclusion of electromagnetic wave shielding and sound absorption.

Implementation Method 1

the resin layer includes an infiltrating portion infiltrating into the nonwoven fabric and a non-infiltrating portion not infiltrating into the nonwoven fabric

Methodology Applied
Scientific EffectCapillary action: Capillary Action

Implementation Method 2

the nonwoven fabric includes a fiber having a birefringence Δn of 0.005 or more and 0.050 or less

Methodology Applied
Scientific EffectBirefringence: Birefringence

Data Source

PatentEP3984737B1Sheet for molding and molded article
Publication Date: 2024.05.29 TOYOBO MC CORP
  • EP3984737B1 patent drawingFigure 1

AI summary

The purpose of the present invention is to provide a sheet for molding that is easily used for various applications. The sheet for molding includes a nonwoven fabric and a resin layer laminated on the nonwoven fabric, wherein the nonwoven fabric includes a fiber having a birefringence Δn of 0.005 or more and 0.050 or less; and the resin layer includes a resin having a number average molecular weight of 5,000 or more and 150,000 or less, and has an infiltrating portion infiltrating into the nonwoven fabric and a non-infiltrating portion not infiltrating into the nonwoven fabric.