How to improve the hydrophilic properties of non-woven fabrics

Improving the hydrophilic properties of non-woven fabrics and fibers can be carried out through physical and chemical methods, which can be summarized as follows.


(1) Modification of original silk. That is, add hydrophilic substances such as polyethylene glycol, sulfonic acid group-containing substances, etc. to the spinning solution to improve the hydrophilicity of the fiber, but this method will affect other properties of the fiber, such as weakening the crystallization of the polymer Ability to reduce its melting point, and affect the physical and mechanical properties of the fiber.


(2) Surface graft modification. High-energy radiation, electron beam radiation or chemical reagents are used to initiate access to hydrophilic groups to increase hydrophilicity.


(3) Change the physical structure of the fiber surface or internal. Such as changing the fiber morphology and structure to make the fiber structure microfibrillated, like natural fibers such as cotton, wool and other natural fibers, have many internal and external micropores, using capillary phenomenon to absorb water; it can also make the fiber cross section profiled or surface rough. This method can only improve the water absorption of the fiber, but cannot improve the moisture absorption of the fiber.


(4) Hydrophilic finishing. The hydrophilic agent is covered on the surface of the fiber to form a hydrophilic film to improve its hydrophilic performance, and the hydrophilic film has a certain degree of conductivity, which can improve the antistatic property of the material. The method is simple and easy to implement, the principle is relatively mature, and the application range is very wide. However, there are few hydrophilic finishing agents with high washing durability at present.


(5) Plasma treatment. Plasma is a fully or partially ionized gas. The gas gains energy under the action of an electric field and is ionized. After the high-energy state of the gas is used to surface the fiber, the surface layer of the fiber forms a cross-linked structure or provides a stable free radical. , The surface of this state will be oxidized in the air, and the free radicals will eventually generate -OH, -COOH and other groups, changing the wetting properties of the fiber, in order to improve the hydrophilic properties of the fiber [2]. At present, a laboratory in the United Kingdom has tested a stable glow discharge plasma reactor, which uses CO2, H2, and O2 to convert the hydrocarbon groups of polypropylene into carbonyl, carboxyl, hydroxyl and other polar groups at room temperature, which significantly improves The hydrophilicity of the material, the entire chemical reaction is irreversible, and the hygroscopicity is relatively durable.


Among the above methods, the hydrophilic finishing has the characteristics of simple method, low cost and significant economic benefits. It can increase the moisture absorption and water absorption of the fiber while basically maintaining the original characteristics of the fiber, so it has become the most widely used one. Kind of method. Of course, hydrophilic finishing has the problem of poor durability. The use of disposable non-woven fabrics does not require high durability. For durable non-woven fabrics, research and development of durable finishing agents is the key. After hydrophilic finishing, the hydrophilicity and comfort of the non-woven fabric are significantly improved, while the antistatic properties, softness and stain resistance are also improved.