Moisture-Permeable Laminate for Low-Temperature Heat Exchange

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Solution Overview

Problem

Hydrophilic polymer compounds used in heat exchange sheets have insufficient moisture permeability, particularly in low temperature and low humidity environments.

Innovation Solution

A laminate comprising a porous substrate with a moisture-permeable membrane on one or both sides, where the membrane is formed from a copolymer containing hydrophilic and hydrophobic groups, providing a balance that enhances moisture permeability while maintaining low air permeability and water resistance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If conventional layering techniques are used to create multi-layered laminates, then manufacturing complexity is reduced, but manufacturing precision deteriorates due to inability to control resin flow and void formation

Engineering Contradiction:
Improvecontrol of resin flow and void formationVSAvoidmanufacturing process complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The laminate structure is segmented into distinct layers with alternating fiber orientations (e.g., 0°, 90°, ±45° plies). This segmentation allows each layer to be optimized for specific structural requirements and enables controlled resin flow patterns during manufacturing, preventing void formation while maintaining manufacturing feasibility through standardized layering sequences.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent utilizes changes in fiber orientation angles (0°, 90°, ±45°) and material properties (thermoplastic vs. thermoset resins, fiber types) to control resin flow behavior. By adjusting these parameters during the forming process, the invention achieves precise control over resin distribution and void prevention without requiring overly complex manufacturing equipment or procedures.

Inventive Principle:
Principle #35Parameter changes

2Strength

If fiber reinforcement is added to plastics to improve mechanical properties, then strength increases, but homogeneity deteriorates due to difficulty in distributing fibers uniformly

Engineering Contradiction:
Improvemechanical propertiesVSAvoidhomogeneity of fiber distribution
Core Design Contradiction:
StrengthVSStability of the object's composition

Solution Approach 1:

The patent employs continuous fiber reinforcement rather than discrete fiber additions. Continuous fibers are embedded throughout the laminate structure in a consistent pattern across all layers, ensuring uniform distribution and consistent mechanical properties. This continuous reinforcement approach maintains homogeneity while maximizing strength, as the fibers are integrated into the resin matrix during the lamination process rather than added separately.

Inventive Principle:
Principle #20Continuity of useful action

3Adaptability or versatility

If multiple materials are combined in laminates to achieve desired properties, then adaptability improves, but manufacturing precision deteriorates due to difficulty in bonding different materials

Engineering Contradiction:
Improverange of desired propertiesVSAvoidbonding of different materials
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent creates composite laminate structures by combining different fiber-reinforced plastic layers (e.g., carbon fiber, glass fiber, aramid fiber) with compatible resin matrices. The composite structure allows each material to contribute its specific properties (strength, stiffness, toughness) while the lamination process ensures strong inter-layer bonding. The use of thermoplastic or thermoset resins as bonding agents facilitates adhesion between different fiber types, achieving both material versatility and manufacturing precision.

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 excellent moisture permeability in low temperature and low humidity environments, making it suitable for use in total heat exchange devices and other applications requiring efficient moisture and heat transfer.

Implementation Method 1

a moisture-permeable membrane that is disposed on one side of the porous substrate

Methodology Applied
Scientific EffectPermeation: Permeation

Implementation Method 2

the resin has a hydrophobic group from the viewpoint of excellent water resistance

Methodology Applied
Scientific EffectHydrophobic effect: Hydrophobe

Implementation Method 3

the resin preferably has a hydrophilic group from the viewpoint of excellent moisture permeability

Methodology Applied
Scientific EffectHydrophilic effect: Hydrophile

Implementation Method 4

exchanging heat between supply air and exhaust air

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 5

Heat exchange ventilation devices that exchange heat between supply air and exhaust air during ventilation

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4129643A1laminate
Publication Date: 2023.02.08 DAICEL CORP
  • EP4129643A1 patent drawingFigure 1
  • EP4129643A1 patent drawingFigure 2
  • EP4129643A1 patent drawing

AI summary

Provided is a laminate having low air permeability and excellent moisture permeability in a low temperature and low humidity environment. The laminate is provided with a porous substrate and a moisture-permeable membrane disposed on one side of the porous substrate, the laminate having an air resistance of 3000 seconds/100 cc or greater based on the Gurley method according to JIS P8117-2009 and a first moisture permeability of 300 g/(m2·24h) or greater based on a moisture permeability testing method (the cup method) according to JIS Z0208-1976 under the conditions of a temperature of 5°C, a relative humidity of 45%, and a wind speed of 0.2 m/s or less.