Dyeable Nanofiber Layer Welded to Fabric for Breathable Waterproof Garments
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Solution Overview
Problem
Current waterproof and breathable garments face issues with water leakage, limited moisture vapor transmission, visible white edges due to undyable microporous materials, and weakened seam areas from stitching, which affect aesthetics and functionality.
Innovation Solution
A composite fabric with a dyeable nanofiber layer of polymeric nanofibers, allowing for high vapor transmittance and liquid water resistance, integrated with a fabric layer and welded to eliminate stitching and post-processing needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If e-PTFE microporous material is used for waterproof and breathable garments, then waterproof and windproof functionality is improved, but the material cannot be dyed resulting in visible white edges that are aesthetically unacceptable
Solution Approach 1:
The patent changes the chemical composition parameter of the microporous material from e-PTFE to a dyeable polymer such as polyurethane, polyester, or polyacrylonitrile. This parameter change enables the material to accept dyes while maintaining the required microporous structure for breathability and waterproofness, thereby eliminating visible white edges and improving aesthetic appearance.
Solution Approach 2:
The patent creates a composite fabric structure combining multiple layers including the dyeable microporous layer, with bonded edges that integrate the microporous material with colored fabric layers. This composite structure allows the microporous layer to be seamlessly integrated into the garment design, hiding any potential white edges through bonding with colored materials.
2Ease of manufacture
If stitching is used to assemble fabric structures containing e-PTFE, then garment construction is achieved, but the stitching weakens the waterproof and windproof functionality at seam areas
Solution Approach 1:
The patent replaces the mechanical stitching system with a thermal bonding system. The dyeable microporous material is thermally bonded to fabric layers at the molecular level through heat and pressure, creating a seamless bond that maintains the integrity of the microporous structure and preserves waterproof and windproof functionality without the holes and weak points created by mechanical stitching.
Solution Approach 2:
The patent utilizes phase transitions (melting and bonding) of the thermoplastic microporous material to join fabric layers. By heating the material above its melting point and then cooling it, the material transitions from solid to molten state and back, creating a strong bond between layers that maintains the microporous structure and waterproof functionality without requiring stitching.
3Reliability
If e-PTFE is used with high melting point, then waterproof breathable functionality is achieved, but thermal seam welding becomes difficult requiring complex feld-seaming techniques
Solution Approach 1:
The patent changes the thermal parameter of the microporous material by selecting polymers with lower melting points (such as polyurethane, polyester, or polyacrylonitrile) compared to e-PTFE. This parameter change enables standard thermal seam welding processes to be used effectively, eliminating the need for complex feld-seaming techniques and reducing device complexity while maintaining waterproof breathable functionality.
4Ease of operation
If breathable materials are used to allow perspiration evaporation, then comfort is improved, but water leakage through the material occurs under rain pressure
Solution Approach 1:
The patent utilizes a microporous material structure with controlled pore sizes that are small enough to block liquid water droplets from penetrating through under rain pressure, yet large enough to allow water vapor molecules to pass through for breathability. This porous structure with selective permeability simultaneously achieves both breathability for comfort and waterproof performance for reliability.
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 seamless, aesthetically pleasing, and functionally robust waterproof and breathable fabric that maintains moisture vapor transmission while eliminating the need for post-processing and stitching, enhancing comfort and durability.
Implementation Method 1
allowing perspiration to evaporate from the wearer to the atmosphere
Implementation Method 2
moisture vapor transmission
Implementation Method 3
liquid water resistance
Implementation Method 4
welded to eliminate stitching
Implementation Method 5
thermal or ultrasonic welding techniques
Data Source
AI summary
A composite wind barrier fabric having the ability to maintain a high MVTR while controlling air permeability. The fabric has a nanofiber layer optionally welded to, and in a face-to-face relationship with, a fabric layer. Optionally a second fabric layer is welded adjacent to and in a face-to-face relationship with the nanofiber layer and on the opposite side of the nanofiber layer to the first fabric layer. The fabric has a Frazier air permeability of no greater than about 25 cfm/ft2, and an MVTR per ASTM E-96B method of greater than about 500 g/m2/day. The nanofiber layer is welded to the fabric layer over a portion of its surface.