What is the difference between waterproof fabric and water repellent fabric? Many people don't know that the two are completely different fabrics. In fact, most of the waterproof clothes on the market are not made of waterproof fabrics but water-repellent fabrics.
What is waterproof fabric?
The principle of waterproof fabric is to coat a layer of grease, paraffin, rubber or various thermoplastic resins on the surface of the fabric to fill the pores on the surface of the fabric and achieve the purpose of waterproofing. But at the same time the breathability of the fabric is gone. The current waterproof treatment often uses a waterproof membrane to prevent water molecules from penetrating deep, but the membrane itself is too fragile, so it depends on the cooperation of the outer fabric, membrane and inner lining to achieve the waterproof function.
The waterproof ability is expressed by the water pressure resistance value, that is, the waterproof cloth with a fixed area is used to block the continuously rising water pressure. When the third drop of water seeps out of the surface, it is the water pressure resistance value of the fabric. Usually, it can reach the maximum when it exceeds 1000mm. Basic water resistance.
Such fabrics include: industrial fabrics such as awnings, tents, water filling dams, oil retaining dikes, etc., which are widely used.
What is water repellent fabric?
The abbreviation of water repellent fabric is W/R fabric. The principle of water-repellent fabrics is that hydrophobic compounds are deposited on the surface of the fibers, leaving pores on the surface of the fabric, through which air and moisture can pass through, and generally form water droplets on the surface of the fabric (like lotus leaves). But it is not really waterproof, but to reduce the absorption of water by the fabric, so that the water can be "pushed away" on the surface of the fabric. If the water stays for a long time, it will still seep into it. Water-repellent processing uses various chemical materials to attach a layer of ultra-fine "needle beds" on the surface of the fabric, so that the tension on the surface of the fabric is less than the cohesive force of water, so that after the water drops, it will form water droplets and roll away instead of spreading and soaking. If this layer of needle bed structure is flattened or covered with oil, the water repellency of the fabric will be greatly reduced, and it will even start to absorb water. The water-repellent effect of the fabric will gradually weaken with washing and long-term use, or even become invalid.
For example: wearing water-repellent clothes, when the sky is raining, you can walk in the rain for
a few minutes, and then you can quickly shake off the water droplets on the surface of the clothes, then the clothes inside you may not be wet, but may It will also be wet. The degree of wetness is related to the amount of water droplets and residence time. If you see a piece of clothing that says "water repellent" on its product introduction page, don't think you can really go for a walk in the rain in it, because the rain will really drench you.
Waterproof fabric VS Water repellent fabric
1. Waterproof fabrics are more durable and waterproof than water-repellent fabrics, and their physical and chemical properties are more stable;
2. Waterproof fabrics usually will not fail due to washing and long-term use.
3. Waterproof fabrics have a higher water pressure resistance index than water-repellent fabrics, usually at least 3000MM or more.
4. Applied to the specific function of clothing, the main function of water-repellent fabric is to reduce the absorption of water by the fabric, so that water can be "pushed away" on the surface of the fabric; waterproof fabric is a completely impermeable barrier, no matter whether the fabric is Absorbs water, it keeps water out.
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