Effect of Workwear Fit on Thermal Insulation: Assessment Using 3D Scanning Technology.

Thermal insulation is a basic property for describing a set of clothing and consists of the thermal resistance of the individual layers of clothing (which depends on the material used and its structure) and also takes into account the air gaps between the layers. Here, the total thermal insulation was measured in a climatic chamber with a thermal manikin. The air gaps were measured using a 3D scanning technique and calculated using the Blender 3D graphics program. Our study shows the effect of size (fit) on the size of the air gaps, as well as the influence of the air gap size on the thermal insulation value (both for static and dynamic conditions with 45 double steps and 45 double arm movements per minute) for workwear. The relationship of the total thermal insulation value on the volume and size of the air gap was described as a second-order polynomial (R2 > 0.8). It was observed that for workwear, thermal insulation did not increase when the air gaps exceeded approximately 30 mm or when the air gap volume reached 50-55 dm. The highest total thermal insulation (~0.23 m°C/W) was achieved when the garment closely fitted the wearer's body (or in this case, the thermal manikin) without excessive tightness.