Effect of garment properties on air gap thickness and the contact area distribution

Abstract

The heat and mass transfer in clothing is affected by the distribution of the air gap thickness and the contact area and this, in turn, results from the interaction between the geometrically complex shape of the human body, garment design, and fabric mechanical properties. In this study, the distribution of the air gap thickness and the contact area in typical shirts and undershirts were investigated using the three-dimensional scanning technique in relation to the garment style and fit, fabric properties, and body regions. This study showed that at the upper trunk the air gap thickness was unaffected by both the garment style and the fit, whereas the shape of the contact area was changed only by the fit. At the lower body the air gap thickness and the contact area changed proportionally with the increase of the ease allowances in the garments. As expected, larger air gaps were formed in shirts but larger contact areas were observed in undershirts. Consequently, results indicated the possibility of modeling the size of air layers in clothing by proper selection of the fabric type and ease allowances in clothing for a given body shape.Keywords air gap thickness, contact area, three-dimensional body scanning, heat and mass transfer in clothingThe thermal, evaporative, and wicking processes in a clothing system are related to the human thermoregulatory response under the given conditions and depend on the factors associated with the fabric properties and construction of the garment. The intensity of the heat and moisture transfer within the clothing ensemble results mainly from the temperature gradient and liquid concentration in the clothing system, which are influenced by the temporal and spatial change in the thickness of the air layers adjacent to the outer surface of the garment or enclosed in between clothing layers and between skin and clothing layers. In the steady-state conditions a layer of still air acts as a thermal insulator, better than textiles, owing to its lower thermal conductivity (e.g. thermal conductivity of air of 0.026 W/mÁK compared to leather and cotton of 0.060 and 0.159 W/mÁK, respectively 1 ). In the case that the air gap thickness exceeds about 8-13 mm, natural convection can take place that additionally intensifies heat and vapor exchange within the clothing system. 2 Furthermore, the direct exchange of moisture can occur provided that the surfaces of the skin and the clothing adjoin. Owing to the wicking effect, moisture can be distributed laterally over the larger area 3,4 and, hence, can effectively add to the heat loss from the skin by increased thermal conductivity of the fabric 5-7 and the evaporation of moisture from the clothing surface. Therefore, it is important to jointly consider the air gap thickness and the contact area for a realistic simulation of dry heat transfer, evaporation, condensation, sorption, and vapor and liquid moisture

A new method to evaluate the dynamic air gap thickness and garment sliding of virtual clothes during walking

“…The proposed/implemented framework could be applied within the garment design industry to assist designers to design close-fitting clothing as well as encouraging further research on dynamic garmentbody interaction. Quantitatively understanding the interaction between the garment and the human body will also be a step forward in the investigation of the correlation between air gap thickness and the thermal properties of functional fabrics 17,36 from traditional static research to dynamic research.…”

A quantification of the preferred ease allowance for the men’s formal jacket patterns

“…The most basic method used to quantify the ease allowance is to measure the difference in the entire circumference between the garment and human body (Ashdown and DeLong 1995;Park and Lee 2013;Frackiewicz-Kaczmarek et al 2015;Mert et al 2016), which is similar to the classical definition of ease allowance. Occasionally, the entire circumference is divided into several segments, and the difference between the garment size and human body size is measured separately for each segment (Wang et al 2006;Kim 2008).…”

Termal Koruyucu Giysilerin Koruma Performansı Üzerinde Hava Boşluklarının Etkisi

“…[12] Frackiewicz-Kaczmarek ve diğerleri (2015) çalışmalarında göm-lek ve atletlerde giysi tipi ve giysinin vücuda uyumunun hava boşluklarının kalınlığına ve temas alanına etkisini incelemiş-lerdir. Çalışma sonucunda gövdenin üst kısmında oluşan hava boşluklarının kalınlığına giysi özelliklerinin herhangi bir etkisinin olmadığı, alt gövdede ise giysi bolluk payının artması nedeniyle hava boşluğu boyutlarının değiştiği belirlenmiştir [22]. Aynı araştırmacılar yaptıkları diğer bir çalışmada ise, farklı oranlarda neme sahip olan iç giysiler için hava boşlukları ve temas alanlarını belirlemişlerdir.…”