What is Hydrophilic & water-repellent naterial?
Hydrophilic and water-repellent materials are two categories of substances classified by their surface affinity for water. Their different interactions with water determine their suitability for diverse scenarios, especially in non-woven fabrics, microfiber products, and pet care supplie
1. Hydrophilic Material
Core Definition
Hydrophilic material refers to a substance that has a strong affinity for water. Water droplets spread quickly on its surface instead of beading up, and the material can absorb water actively through capillary action.
Key judgment index: The contact angle between water droplets and the material surface is less than 90° (the smaller the angle, the stronger the hydrophilicity).
Core Characteristics & Mechanism
Strong water absorption: The material surface has polar groups (e.g., hydroxyl, carboxyl), which form hydrogen bonds with water molecules, driving water to penetrate and spread.
Breathable & moisture-wicking: After absorbing water, it can quickly transfer moisture to the surface for evaporation, avoiding stuffiness.
No water beading: Water spreads into a thin film on the surface, without forming discrete droplets.
Hydrophilic Modification Methods for Non-woven Fabrics
Add hydrophilic surfactants during fiber spinning to introduce polar groups on the fiber surface.
Use plasma treatment or UV irradiation to etch the fiber surface and increase water contact points.
2. Water-repellent Material
Core Definition
Water-repellent material refers to a substance that has weak affinity for water and can resist water penetration. Water droplets form spherical beads on its surface and roll off easily, without wetting the material.
· Key judgment index: The contact angle between water droplets and the material surface is greater than 90°; when the angle exceeds 150°, it is called superhydrophobic material.
Core Characteristics & Mechanism
· Water resistance & stain resistance: The material surface has non-polar groups (e.g., alkyl, fluorine-containing groups) that repel polar water molecules, forming a "water-repellent barrier".
· Moisture permeability (for functional fabrics): Unlike completely waterproof materials (e.g., plastic films), high-quality water-repellent non-woven fabrics can allow water vapor to pass through, keeping the surface dry without stuffiness.
· Easy to clean: Water droplets carry away surface dirt when rolling off (the "lotus leaf effect").
Water-repellent Modification Methods for Non-woven Fabrics
Coating treatment: Apply water-repellent agents (e.g., silicone, fluoropolymer) on the fabric surface.
Fiber blending: Mix water-repellent fibers (e.g., PP fibers) with other fibers during non-woven fabric production.