Waterproof Vs. Water Repellent Vs. Water Resistant
This looks above three terms are alike but there is a difference between waterproof, water repellent and water resistant. We must at the very beginning distinguish between “waterproof” and “water-repellent” textile surfaces. When you start to add breathability into the mix, things can start to get a little complicated. So, you should have clarified what do they all mean and why should you take note of the differences?
Waterproof fabrics are fabrics that are inherently or have been treated to become, resistant to penetration by water and wetting. The term “waterproof” refers to conformance to a governing specification and specific conditions of a laboratory test method.
Even when you put pressure on a waterproof garment, it will still be impervious to water. The amount of pressure you can put on the garment before you start to get wet varies, and you can find out what that amount is by checking the garment’s water column.
Water-repellent treatment is a standard finishing process for modern textiles in order to create breathable textiles. Water-repellent agents exploit the high-water repellency of silicones without impairing the textiles’ ability to breathe. Additionally, they confer a soft hand on textiles.
Water repellency is, therefore, a step up from water resistance. This means that water can’t easily penetrate the material (the technical term is that it’s hydrophobic).
- Not easily penetrated by water, especially as a result of being treated for such a purpose with a surface coating. It beads on the outside instead. The fabric is a densely woven and it offers some water resistance.
- Adjective (of fabrics, garments, etc) having a finish that resists the absorption of water
- Adjective having a finish that resists but is not impervious to water.
- Water-repellent clothing or material does not absorb water when it is raining lightly
- Able to keep rain from being absorbed.
This offers the lowest level of water protection. If a garment resists water, it’s usually because the fabric itself is acting as a barrier between you and a light shower. Tightly woven fabrics will offer a degree of water resistance, as it takes some time for the water to seep through the material.
- Able to resist the penetration of water to some degree but not entirely
- Resisting though not entirely prevent the penetration of water.
The Definition of Breathability
In a nutshell, breathability refers to the ability of a fabric to absorb moisture and release it through the material itself, allowing it to ‘breathe’. Breathable means that a fabric permits perspiration vapors to escape from the body through the fabric. During strenuous activity, the body releases moisture vapors, and the skin breathes this moisture as it naturally tries to cool itself down.
Breathable Fabrics transmit body moisture away from the body, thus maximizing comfort and dryness during outdoor activities. This continuous cycle of motion is at the heart of the mechanism of breathability: the more you sweat inside a breathable clothing item, the higher its perspiring capacity should be, and this circular action never stops.
Breathability does not, as the term might imply, relate to an exchange of air. Instead, it is the ability of a fabric to allow moisture vapor to pass through it. A fabric may carry this out in numerous different ways, and exchange of air is only one possible avenue. Moisture vapor permeability (MVP) and moisture vapor transmission (MVT) are perhaps better, and certainly more technical, terms to use than breathability. Neither ASTM nor the Textile Institute defines breathability, but MVP and MVT are both defined in test standards.
Air permeability is intrinsically linked to breathability. Air permeability is “the velocity of an air flow passing perpendicularly through a test specimen under specified conditions of the test area, pressure drop, and time” (according to BS EN ISO 9237: 1995). All air permeable fabrics are breathable to some extent, though not all breathable fabrics are air permeable.
Application of durable water-repellent finishes by coating methods
Measuring the surface tension of the liquid, one may calculate the work of adhesion between the liquid and the surface of the solid. It is clear that the smaller the work of adhesion, the smaller will be the wettability and the greater will be the repellency.