How Can Closed-Cell Y-Warm Be Moisture-Permeable and Quick-Drying?

Y-Warm combines two properties that may initially appear contradictory: an engineered closed-cell structure for thermal insulation and moisture permeability with quick-drying performance.

The key to understanding this combination is that thermal insulation and moisture management are governed by different aspects of the material.

Y-Warm’s closed cells restrict internal gas movement and help reduce heat transfer, while its hydrophilic polymer chemistry and high internal specific surface area interact with moisture and support its transfer and evaporation.

Therefore, Y-Warm does not need an interconnected open-pore structure to provide moisture-management functionality.

Closed Cells and Moisture Permeability Are Not the Same Property

A closed-cell structure means that the individual cells within Y-Warm are separated rather than forming a continuously interconnected pore network.

This architecture restricts internal gas movement and contributes to the material’s low thermal conductivity.

However, closed cells do not by themselves determine how the polymer interacts with water or water vapor.

Y-Warm incorporates hydrophilic functional groups within its polymer system. These groups allow the material to interact with moisture, while its high specific surface area supports moisture distribution and evaporation.

This distinction is important:

Closed-cell structure primarily contributes to thermal insulation.

Hydrophilic material chemistry primarily contributes to moisture management.

How Does Moisture Move Through Y-Warm?

Y-Warm does not rely on bulk airflow through its closed cells to manage moisture.

Instead, moisture management involves interaction between water molecules and the hydrophilic polymer structure.

When the side facing the body is exposed to a warmer and more humid environment, moisture can be absorbed by the material and distributed through the hydrophilic structure. Under suitable temperature and humidity conditions, moisture can then migrate toward the lower-humidity side and evaporate.

The process can be summarized as:

Moisture absorption → moisture transfer → evaporation

This allows Y-Warm to combine thermal insulation, moisture permeability, and quick drying within a single ultra-thin material.

Moisture Absorption and Drying Performance

Testing has shown that Y-Warm exhibits strong moisture absorption and drying characteristics.

Under the specified test conditions:

• its measured water absorption was approximately 280% of that of the reference sample; and

• its measured drying rate was approximately 2.5 times that of the reference sample.

These results indicate that Y-Warm can interact with moisture efficiently and release absorbed moisture relatively quickly under the specified conditions.

The results should be interpreted according to the corresponding test methods and test conditions.

What Does the Moisture-Permeability Test Measure?

Third-party testing has reported a water-vapor transmission value of approximately:

3,800 g/(m²·24 h)

for Y-Warm under the specified test conditions.

This value describes performance under a particular laboratory test method. It should not be interpreted as a complete measure of wear comfort, moisture-management performance, or drying behavior.

Water-vapor transmission is influenced by factors including:

• test method;

• temperature and relative humidity;

• vapor-pressure gradient;

• material thickness;

• moisture absorption;

• test duration; and

• material structure.

For a hydrophilic material such as Y-Warm, moisture can be temporarily absorbed within the material during testing before subsequently being transferred and released.

Therefore, water-vapor transmission, moisture absorption, drying rate, and perceived comfort describe related but different aspects of moisture management.

Why Can't Y-Warm's 3,800 g/(m²·24 h) Be Directly Compared with 20,000 g/(m²·24 h)?

Water-vapor transmission values should only be compared directly when they are obtained using comparable test methods and conditions.

A fabric reported at 20,000 g/(m²·24 h) is not automatically more comfortable than another material reported at 3,800 g/(m²·24 h).

The numerical value alone does not describe:

• how much moisture the material can absorb;

• how quickly absorbed moisture is distributed;

• how quickly it dries;

• how moisture behaves during changing activity levels; or

• how the complete garment manages heat and moisture.

This is particularly important when comparing hydrophilic moisture-managing materials with conventional vapor-permeable fabrics or membranes, because their moisture-transfer mechanisms may differ.

Therefore, the 3,800 g/(m²·24 h) result should be interpreted as one measured parameter, rather than as a complete representation of Y-Warm’s moisture-management performance.

Why Can a Hydrophilic Material Affect a Short-Duration Vapor Test?

Y-Warm’s hydrophilic structure can absorb moisture during the early stages of exposure.

In a short-duration test, part of the moisture entering the material may therefore remain temporarily within the material rather than immediately reaching the opposite side.

This means that moisture storage and moisture transmission can occur simultaneously.

The extent to which this behavior affects a specific measured water-vapor transmission value depends on the test method and moisture-transfer kinetics.

Without time-resolved measurements, it should not be assumed that a short-duration test necessarily captures the material’s complete moisture-management behavior.

What Should Be Evaluated for Moisture Management?

For Y-Warm, moisture performance is better understood by considering several parameters together rather than relying on a single water-vapor transmission value:

A single moisture-permeability value cannot fully describe the moisture-management behavior of a hydrophilic thermal insulation material.

Third-Party Verification Report:

Y-Warm,Beijing Matrix Technologies Co.,Ltd.