Analysis of heat transfer and factors affecting the thermal propertieson rib 1x1 knitwear

Abstract

Clothing comfort is very important feature which is considered as a result of different process of heat exchange between human body, clothing and environment. The purpose of this paper is to analyse the impact of clothing insulation on the heat transfer. The measurements were carried out on commercially 1x1 RIB knitted fabrics used for the production of next-to-skin shirts. The one group of samples are made from 100% cotton yarn and another with 96% cotton and 4%lycra. It is noticed that knitted material composition affected the change in heat resistance. Also, this paper presents and verifies the correlation between the measured values of thermal resistance (Rct) and the knitwear thickness (dpl), the covering factor (K), the porosity of the twists (e) and the surface coefficient (dp). Based on these results, a mathematical model for calculating thermal resistance is proposed. Comparing the results obtained with the proposed equation and the measured results, we can see that the deviations are minimal. The highest deviation for sample C4 is 0.05%,while the largest deviation for sample CL4 is 4.6%.

Studying the influence of common wet processes on the quality of 1 × 1 rib cotton/elastane knitted fabrics

“…This paper 18 demonstrated that once the fabric has been knitted, the loop length and width along with the shape that it takes in the fabric after each relaxation state will be the main factors responsible for fabric dimensional variations. Besides the dimensional stability of 1 × 1 rib knitted fabrics, their thermal 19 and mechanical 20,21 properties were also examined. Pešić et al 19 found a significant correlation between the bleached and dyed cotton and cotton/Lycra fabric thermal resistance and different fabric parameters like thickness, covering factor, and the surface coefficient.…”

“…Besides the dimensional stability of 1 × 1 rib knitted fabrics, their thermal 19 and mechanical 20,21 properties were also examined. Pešić et al 19 found a significant correlation between the bleached and dyed cotton and cotton/Lycra fabric thermal resistance and different fabric parameters like thickness, covering factor, and the surface coefficient. 1 × 1 rib knitted fabrics having Lycra in their compositions were more compact and possessed higher heat resistance than 100% cotton fabrics.…”

“…Furthermore, a slight change in the yarn fineness (from 20 to 14 tex) resulted in 13% and 16% lower thermal resistance of cotton and cotton/Lycra fabrics, respectively. 19 Tensile strength and elongation at break of 1 × 1 rib knitted fabrics made from 100% cotton and cotton/Lycra yarns were investigated by Sitotaw and Adamu and Adamu. 20 The authors underlined that fabrics having Lycra are characterized by higher elongation at break and lower breaking force as compared to those made of 100% cotton yarn.…”