Nanofiber Layer Composite for Wind Resistance and Breathability
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Solution Overview
Problem
Existing protective garments for wet conditions struggle to balance air permeability and moisture vapor transmission, with breathable materials often wetting through from rain and failing to maintain comfort through natural evaporative cooling.
Innovation Solution
A composite fabric construction featuring a nanofiber layer adjacent to and bonded with fabric layers, providing controlled air permeability and high moisture vapor transmission rates through the use of polymeric nanofibers produced by electrospinning or meltblowing, with optional calendering and post-processing to achieve desired properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If breathable materials are used to allow perspiration evaporation, then moisture vapor transmission is improved, but air permeability becomes uncontrolled and rain penetration occurs
Solution Approach 1:
The garment is divided into multiple functional layers: an outer shell layer for wind and rain protection, a mid-layer nanofiber membrane for moisture vapor transmission, and an inner comfort layer. This segmentation allows each layer to specialize in one function, resolving the contradiction between breathability and weather protection.
Solution Approach 2:
The patent uses composite material construction combining different fabric types and a nanofiber membrane with specific porosity characteristics. The outer shell uses tightly woven fabric for wind/rain blocking, while the nanofiber mid-layer provides controlled vapor transmission, creating a composite structure that simultaneously achieves both protection and breathability.
2Ease of operation
If microporous films are used to control air permeability, then air flow management is improved, but moisture vapor transmission is limited
Solution Approach 1:
The patent employs a nanofiber membrane with specifically engineered porosity and pore size distribution. The porous structure allows selective passage: small water vapor molecules can diffuse through the pores while larger air currents and liquid water droplets are blocked. This resolves the contradiction by using material pore characteristics rather than mechanical closure mechanisms.
Solution Approach 2:
The nanofiber membrane parameters (porosity, pore size, fiber diameter, density) are optimized to create a selective barrier. By changing these physical parameters, the material allows vapor transmission while restricting air flow, achieving both air flow management and moisture vapor transmission simultaneously.
3Object-affected harmful factors
If waterproof materials like polyurethane coatings are used, then rain protection is improved, but perspiration evaporation is blocked
Solution Approach 1:
Instead of using rigid waterproof coatings that block all vapor transmission, the patent employs a flexible nanofiber membrane that acts as a selective barrier. The thin film structure with controlled porosity allows water vapor molecules to pass through via diffusion while blocking liquid water from rain, maintaining both rain protection and evaporation capability.
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 effectively manages airflow and moisture vapor transmission, maintaining wearer comfort and dryness while reducing air permeability, as demonstrated by significant improvements in Frazier air permeability and MVTR measurements across various fabric constructions.
Implementation Method 1
the inner layer and the outer layer each comprise at least a portion that is permeable to water vapor
Implementation Method 2
allowing perspiration to evaporate from the wearer to the atmosphere
Implementation Method 3
GB 2 416 781 A discloses a typical layered material that is permeable to water vapor, but impermeable to liquid water
Implementation Method 4
the amount of perspiration transmitted from inside to outside so that the undergarments do not become wet and so natural evaporative cooling effects can be achieved
Data Source
AI summary
An article of apparel having the ability to maintain a high MVTR while protecting the wearer from wind. The garment has a nanofiber layer bonded to, and in a face-to-face relationship with a fabric outer layer. Optionally a second fabric layer is bonded adjacent to and in a face-to- face relationship with the nanofiber layer and on the opposite side of the nanofiber layer from the first fabric layer. The fabric has a Frazier air permeability of no greater than about 7.6 m3/m2/min, and an MVTR of greater than about 500 g/m2/day.