Determination of the Air Gap Thickness underneath the Garment for Lower Body Using 3D Body Scanning Emel MERT 1,2 , Sonja BÖHNISCH 1,3 , Agnes PSIKUTA* 1 , Marie-Ange BUENO 2 , Rene M. ROSSI 1 1 Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Protection and Physiology, St. Gallen, Switzerland; 2 Univ. de Haute Alsace, Laboratoire de Physique et Mécanique Textiles, Ecole Nationale Supérieure d’Ingénieurs Sud Alsace, Mulhouse, France; 3 Hochschule Albstadt-Sigmaringen, Germany DOI: 10.15221/15.114 http://dx.doi.org/10.15221/15.114 Abstract The heat and mass transfer between the human body and its surroundings is affected not only by the properties of the fabrics, but also by the shape and the thickness of the air layer between the garment and the human body due to the low conductivity of the stagnant air. Therefore, it is important to accurately determine the thickness of air layers between the body and the garment. The aim of this study was to accurately evaluate the change in the air gap thickness at the lower body for different garment fit (tight, regular and loose) and style (3/1 twill woven trousers and single jersey sweatpants). A standing stationary manikin, the highly accurate 3D body scanning and post-processing method developed in previous studies were used to determine the thickness of the air layers between the body and the garment. The results showed that the regional body sections had the strongest effect on the air layers beneath the garment. The garment fit had stronger effects on the air layers at the legs than the pelvis area due to body geometry and the garment style. This finding is useful for clothing modelling and design, and it implies that the modelling of air layers at the pelvis and the legs is possible, since the observed trends were unambiguous. The results of this study can contribute to an improved design of protective clothing and active sport garments. Furthermore, it will help to improve the simulations of the heat and mass transfer for lower body garments in various fit and design. Keywords: air gap, 3D body scanning, lower body, heat and mass transfer in clothing 1. Introduction The clothing is an important interface between the body and its surroundings for protection against external hazards and harsh environmental conditions. It provides a microclimate, in which the human body attempts to keep its wellbeing. The heat and mass transfer between the human body and its surroundings is affected not only by the properties of the fabrics, but also by the shape and the thickness of the air layer between the garment and the human body due to the low conductivity of the stagnant air [1, 2]. The garment properties have an effect on the distribution of air gap thickness over the body. In previous studies, the distribution of the air gap thickness and the effect of the garment properties (fit and style) on the air layers have been investigated for upper body [3, 4]. However, none of the studies focused on the distribution of the air layers for the lower body garments and the interaction between the lower body geometry and the garment properties. To understand the similarities or to distinguish the differences between the distribution of the air layers for upper and lower body garments, it is necessary to have a systematic study for lower body garments in different fit and style. In the presented study, the distribution of the air gap thickness at different garment fits, such as tight, regular and loose fit, and styles, such as trousers and sweatpants, were determined on the motionless male manikin using advanced 3D scanning and post-processing method developed in previous study. The results of this study can contribute to an improved design of protective clothing and active sport garments. Furthermore, it will help to improve the simulations of the heat and mass transfer for lower body garments in various fit and design. 2. Method 2.1. Fabrics and garments In the presented study, plain jersey knitted fabric, which contained 95% of cotton (CO) and 5% of spandex fibre (SP), was used to sew the sweatpants. Additionally, 3/1 twill woven fabric, which consists of 100% cotton, was used to confection the trousers (Table 1). The Fabrics were washed with gentle washing program at 40°C and dried to remove any foreign material, such as dust, soil, dye waste and the tensions of the manufacturing process from the fabric [5]. * agnes.psikuta@empa.ch, phone: +41 58 765 76 73, Fax: +41 58 765 77 62 6th International Conference on 3D Body Scanning Technologies, Lugano, Switzerland, 27-28 October 2015 114