Technical Methods For Enhancing Moisture Absorption And Sweat Perspiration Of Polyester Fabrics

　　 1. moisture absorption and perspiration Mechanism

The mechanism of moisture absorption and sweat transmission of fabrics: the transmission of sweat to fabrics can be generally divided into four stages: the contact and wetting and absorption of fabrics and sweat, the transmission of sweat, the storage or retention of sweat, and the evaporation of sweat from the fabric surface. Therefore, after sweating, the sweat does not spread on the inner surface of the fabric, but is directly absorbed into the outer layer of the fabric, evaporating on the outer layer of the fabric to keep the inner layer of the fabric relatively dry, reducing the adhesive effect between the human body and the fabric, improving the comfort of human body and the movement function of the human body.

　　 2. the main factors affecting the hydrophilicity of polyester fibers or fabrics

(1) surface and section shape of single fiber

Fiber with slight concave convex or irregular shape has good water absorbency. This is because the change of the smooth and intact surface structure of the fiber not only increases the specific surface area, but also increases the affinity for the water molecules. Moreover, the water retention in the gap between fibers is increased by the principle of microporous capillary water absorption.

(2) species and quantity of hydrophilic groups

The type of hydrophilic group is very important. Polar groups such as base, amino, phthalamide, and moxyl have strong affinity for water molecules. Therefore, the more the polar group in the fiber molecular structure or the fiber surface, the better the hygroscopicity.

(3) supramolecular structure of fibers

The higher the crystallinity of the fiber, the worse the water absorbency. This is because the molecules in the fibrous crystalline region are closely arranged regularly, and the polar groups are cross-linked between molecules. Water molecules are not easy to infiltrate into the crystalline region.

　　 Three hygroscopic and sweat releasing Finishing method

There are many ways to improve the hygroscopicity of polyester fabrics, such as blending, hydrophilicity of macromolecular structure, graft copolymerization with hydrophilic materials and surface treatment of fibers. Using hydrophilic agents to make them evenly and firmly anchored on the surface of fibers to form hydrophilicity is the development direction of moisture absorbent and perspiration finishing of synthetic fabrics in recent years. (1) chemical modification: there are mainly three ways to improve the hydrophilicity of polyester fabrics: hydrophilicity of macromolecular structures, graft modification with hydrophilic monomers, and hydrophilic treatment of fiber surfaces. (2) physical modification: there are three main ways to improve the hydrophilicity of polyester fabrics by physical means: blending with hydrophilic materials or composite spinning, heterogeneous treatment of fiber structure and surface roughening of fibers.

　　 Four Polyester fabric Moisture absorption finishing

Due to the high requirement of the physical modification method to the spinning equipment, the cost of moisture absorption and sweating polyester fabric is increased. In this paper, a new type of finishing agent A, which is provided by the enterprise (because the new product is not convenient to provide the name and ingredient) and the traditional cationic moisture absorption and sweating finishing agent B, makes it evenly and firmly anchored on the surface of the fiber to form a hydrophilic group. There are three processes for sweating completely from sweat to fabric. First of all, sweat absorbs sweat from the skin and fabric, and the sweat diffuses in the fabric. At last, sweat evaporates from the fabric. Any step in the three step will not affect the wearing comfort. Therefore, at least three tests should be selected, and each test is a step in the process of sweating, to comprehensively evaluate the moisture absorption and sweat perspiration performance of the fabric. Therefore, this paper chooses to evaluate the finishing effect of A finishing agent and B finishing agent by testing the comprehensive value of capillary effect, drying rate, durability, moisture conductivity and permeability.