Multi-Layer Cooling Fabric with Phase Change Beads
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Solution Overview
Problem
Existing wet-activated cooling fabrics quickly dry out and warm up, negating their cooling effect, as they lack advanced yarns and construction techniques to provide sustained cooling for an extended duration.
Innovation Solution
A multi-layer knitted fabric construction using a combination of stretchable synthetic yarn, evaporative yarn embedded with minerals, and highly absorbent bi-component polyester and nylon yarns, along with a yarn designed for moisture transport, facilitates evaporative cooling by creating hydrophobic and hydrophilic channels for perspiration and evaporation, maintaining a cooling effect even when dry.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If traditional woven and double knit constructions with absorbent yarns are used, then the fabric can provide initial cooling effect, but the cooling effect is short-lived as the fabric quickly dries out and warms up to skin temperature
Solution Approach 1:
The fabric is divided into multiple functional layers with distinct roles: a first layer with absorbent yarns for moisture management, a second layer with phase change material microencapsulated beads for sustained cooling, and a third layer with evaporative yarns for continuous cooling. This segmentation allows each layer to perform its specific function optimally, preventing the cooling effect from dissipating quickly as in traditional single-layer fabrics.
Solution Approach 2:
The invention combines multiple material types with different thermal properties: absorbent polymers for moisture wicking, phase change material microencapsulated beads for latent heat storage and release, and evaporative yarns for continuous cooling. This composite structure enables the fabric to maintain cooling effect over extended periods by utilizing different cooling mechanisms simultaneously.
2Quantity of substance
If more absorbent yarns are used to enhance moisture absorption, then the fabric can maintain wetness longer, but the fabric complexity and construction difficulty increase
Solution Approach 1:
Instead of uniformly increasing absorbent material throughout the fabric, the invention segments moisture management functions across different layers: the first layer handles initial moisture absorption, the second layer provides phase change cooling, and the third layer enables evaporative cooling. This segmentation achieves enhanced moisture retention without proportionally increasing overall fabric complexity.
Solution Approach 2:
The fabric layers are designed to perform multiple functions: the absorbent yarns not only absorb moisture but also facilitate evaporation; the phase change material layer provides both thermal insulation and active cooling; the evaporative yarns contribute to both moisture transport and cooling. This multi-functionality reduces the need for additional specialized components, thereby limiting complexity increase.
3Temperature
If traditional cooling fabrics are used, then the fabric structure is simple, but the cooling power and temperature reduction capability are insufficient
Solution Approach 1:
The invention incorporates phase change material microencapsulated beads within the fabric structure, combining them with traditional textile fibers. This composite approach enables significant temperature reduction capability (up to 30°F below body temperature) by utilizing the latent heat of fusion of the phase change material, which melts at skin temperature and absorbs heat from the body during the phase transition.
Solution Approach 2:
The fabric utilizes phase change material that transitions from solid to liquid at skin temperature (approximately 98.6°F). This phase transition absorbs large amounts of heat from the body without significant temperature increase, providing sustained cooling. The microencapsulated beads are distributed throughout the fabric to maximize the phase change surface area and cooling efficiency.
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 fabric achieves a temperature decrease of up to 30°F below body temperature, provides up to 30% increased conductive cooling power, and maintains cooling for up to two hours after wetting, with additional benefits of UV protection and a cool touch feel.
Implementation Method 1
evaporative yarn embedded with minerals... facilitates evaporative cooling by creating hydrophobic and hydrophilic channels for perspiration and evaporation
Implementation Method 2
creating hydrophobic and hydrophilic channels for perspiration and evaporation
Implementation Method 3
phase change material microencapsulated beads... provides up to 30% increased conductive cooling power
Implementation Method 4
highly absorbent bi-component polyester and nylon yarns... provides a sustained cooling effect
Data Source
AI summary
Disclosed herein is a knitted multi-layer fabric construction that provides the ability to cool skin to below a current temperature whether wetted or dry. The knit uses four separate yarns which collectively work together to produce enhanced cooling. Knits can include warp knit, seamless, hosiery, flat bed, spacer, and double knits. Various finishing methods may also be employed to enhance the cooling power of the fabric.