1. Effect on weight

The change of moisture regain rate will of course cause the weight of the textile material to change, here it needs to be emphasized that in the trade is based on the nominal weight as the basis for payment, otherwise either the buyer suffers a loss (the material is wet) or the seller suffers a loss (the material is dry), losing the fairness of trade, which is also one of the main reasons for trade disputes; In production, weight control per unit length (quantitative control) is carried out, and the weight of the fiber material increases proportionally with the increase in the amount of moisture absorbed.

 2. Effect on length and cross-sectional area

An increase in moisture regain causes the fiber volume to expand, that is, the lateral expansion is much greater than the longitudinal expansion.

Reason: macromolecules are arranged in the axial direction, and the molecular spacing increases after moisture absorption, while the length of macromolecules does not increase.

Changes in fabric structure before and after fabric moisture absorption

3. Effect on density

4. Effect on mechanical properties

The change of moisture regain leads to a change in the mechanical properties of the fiber, which in turn affects the processing of textiles and the quality of products. If the moisture regain rate is too low, the rigidity of the fiber will become larger and brittle, easy to break during processing, and the phenomenon of static electricity is also obvious; If the moisture regain rate is too high, the fiber will not be easy to loosen, the impurities in it are difficult to remove, it is easy to entangle and kink with each other, and it is easy to entangle the parts on the machine, which will cause fluctuations in combing, drafting, weaving and other processes.

5. Effect on thermal properties

With the increase of moisture regain rate, the thermal insulation performance of textile materials gradually decreases, the feeling of coolness increases, the ignition temperature rises, the glass transition temperature decreases, the heat shrinkage rate increases, and the anti-fusing ability is improved. Changes in moisture regain have a great influence on the thermal properties of materials.

6. Effect on electrical properties

Textile materials are insulating materials, but their insulation properties will decrease with the increase of moisture regain rate, dielectric loss will increase, and static electricity phenomenon will decrease.

7. Effect on optical properties

When the moisture regain increases, the light refractive index of the fiber decreases. The absorption of light increases, the color becomes darker, and photodegradation and aging intensify.