Author: Nsasithorn

Air Permeability Property Study of Quick Dry Inner Wear

Wenyi Wang1, Hin-heng1, Lois Yim1, Chi-wai Kan1*, Wipada Krajangpo2, Somchai Udon3
and Rattanaphol Mongkholrattanasit2*
1Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hung Hom, Hong Kong, China
2Faculty of Industrial Textiles and Fashion Design, Rajamangala University of Technology Phra Nakhon, Thailand
3 Faculty of Textile Industry, Rajamangala University of Technology Krungthep, Bangkok, Thailand
*corresponding author: tccwk@polyu.edu.hk; rattanaphol.m@rmutp.ac.th

Abstract
Air permeability is an importance factor determining the quick dry property of inner wears. This study aims to evaluate the air permeability of women’s quick dry inner wears in the market (Three brands were selected due to their different market position: Brand A: online brand; Brand B: youth market and Brand C: general market) by using the automatic air permeability tester. It was found that Brand B product was the optimal choice in terms of air permeability.

Introduction
Air permeability is a critical parameter in determining the quick dry property of inner wear. Nowadays, there are quite a lot of quick dry inner wears available in the market. The present study aims to investigate the quick dry performance of such products in Hong Kong market by comparing their air permeability properties of three common commercial inner wears (Brand A: online brand; Brand B: youth market and Brand C: general market).

Experiment
1. Fabric samples
Three women’s quick dry inner wears Brand A: online brand; Brand B: youth market and Brand C: general market) were obtained in Hong Kong market. They were all made of 100% cotton with the quick dry technology, which could provide the good sensation while wearing in summer. The appearance and weave parameters for three brands were shown Figure1 and Table 1. All samples were conditioned in the standard condition at least 24 hours prior to wicking test with the temperature at 20 ± 2°C and the relative humidity at 65 ± 2%.

Table 2 Air permeability of three different samples

Brand	Average air permeability (KPa.s/m)	Standard deviation
Online brand	0.09	0.013
Youth market	0.05	0.008
General market	0.12	0.022

Effects of fabric characteristics on air permeability
Figure 2(A) shows the negative correlation between fabric density and air permeability. This means that the lower the density is, the better the air permeability fabric gets. The positive correlation between air permeability and weight is shown in Figure 2(B). The heavier fabric means higher air permeability value, resulting in poorer air permeability properties.

Online brand (A)	Youth market (B)	General market (C)

Figure 1 Fabric appearance and construction of three brands

Table 1 Fabric parameters

Parameters	Brand
	Online brand	Youth market	General market
Wale/cm	11.9	14.2	13
Course/cm	20.5	18.8	17
Fabric density/cm2	243.90	266.96	221.00
Fabric weight (g/m2)	80.50	101.25	73.75
Fabric thickness/cm	0.074	0.072	0.072

2. Air permeability measurement
Air permeability is an important factor which can affect the moisture and heat transfer [1]. It can be measured according to the standard of KES-F8-AP1.

Results and Discussion
- Air permeability results
The smaller value means better air permeability of fabric. Air permeability results are shown in Table 2. It can be clearly seen that the air permeability of Brand B is 0.05 KPa.s/m, which is lower than that of Brand A and Brand C. This indicates that Brand B has the best air permeability compared to Brand A and Brand C, which could be explained by the fabric characteristics of Brand B.

Figure 2 Effects of fabric characteristics: (A) density; (B) weight; and (C) thickness
on air permeability.

Air permeability affects the heat and moisture transfer of inner wear. In other words, it controls the heat and moisture comfort of inner wear. Therefore, it is an important factor controlling the effectiveness and comfortability of quick dry inner wear.
From the discussion, better air permeability properties can be found in the samples with low density, lighter yarn and thicker fabric. Brand B has the least density and lightest weight. Also, it is thicker than Brand C which shows the highest density, heaviest weight and thinnest fabric. Therefore, Brand B has the best air permeability among all while Brand C has the worst.

Conclusion
This study investigated the air permeability properties of three brands of inner wears for woman in Hong Kong market. It was found that Brand B showed the best quick dry property because of the excellent air permeability property.
References
[1] Vimal, T. J., Murugan, R. and Subramaniam, V. Effect of Weave Parameters on the Air Resistance of
Woven Fabrics. FIBRES & TEXTILES in Eastern Europe, 24(2016) 1, 67-72.
[2] Mccann, J. and Bryson, D. Textile-led Design for the Active Ageing Population. Oxford: Woodhead
Publishing Limited (2014).