Study On Influence On Thermal Comfort Of Knitted Fabrics In Winter Use

Thermal comfort is one of the fundamental property in clothing, involving psychological comfort, physical comfort and the other aspects. It contains both the thermal comfort of the steady-state and the transient-state. And the later also plays an important rule in evaluating its thermal comfort level.How to improve the performance of clothing comfort has always been the focused point and the front subject in the research of modern clothing. It represents the trend that our society is developing constantly and the standards of our lives has greatly been improved.The thermal comfort of a garment will become especially important when it comes to winter clothing. With the rapid development of knitted garments, people show more and more interest in it because of its excellent thermal comfort, elegant appearance and the flexibility in design. Therefore, the improvement of the thermal comfort of knitted garments in winter is of practical significance.This paper mainly discussed the transient warm-cool feeling, thermal conductivity of the common clothing made of wool fiber and influence of wind on the warm retention of winter clothing. In order to analysis the influence of fabric structure, yarn count and fabric density on the thermal comfort, thirty-five peaces of samples were made and divided into five groups. Qmax, which is maximum heat flux in the transient heat transfer is used to describe how warm or cool the fabrics feel in the transient state. Meanwhile, thermal conductivity and warm retention were used to reflect the thermal comfort in steady-state.Taking practical function into consideration, this article mainly summarizes how these factors influence the thermal comfort of the knitted fabrics. Then based on the results found in this article, better design plans for winter knitted products are given. Three main conclusion were drawn as below:(1) The pumping needle proportion, proportion of floating line, tuck proportion, weight per unit area and yarn count all have significant influences on the thermal comfort in both steady-state and the transient state. To make it more specific, both the transient state and steady-state thermal comfort level of the knitted fabrics decreases with the increase of yarn count. But that will increase when the tuck proportion of the fabrics increases. The transient state thermal comfort level and steady-state thermal comfort level will both decrease as the proportion of floating line increases. Moreover, the thermal comfort of the knitted fabrics of both state reaches a high level when pumping needle proportion is about 15% and turns to the opposite when weight per unit area of the fabric is round 240g/m2.(2) The Qmax results of the right side and the reverse side of the fabrics vary differently when it comes to the factor of proportion of floating line, tuck proportion, weight per unit area and yarn count because of the different surface of both sides of the fabrics. Meanwhile, the results of the thermal conductivity stay nearly the same.(3) The significance levels of the five groups vary differently when it comes to the Qmax of the fabrics. But all the results are of extremely significance and show no difference to thermal conductivity.(4) The thermal performance becomes better and better with the increase of the wind speed. Put it another way, it means that the relative better heat preservation will be achieved when people are wearing clothing in windy environment.