Study On Thermo-Wet Comfort Of Leather Wear By Micro-3D Comormation Of Collagenous Fiber

Famous for lightness, warmth, and luxury, nature leather has always on the focus of people. As for clothes made of natural leather, comfort performance has got more attention on the basis of their fashion and quality. This thesis took different parts of sheep leather as samples, which were then embedded and sliced to get sequences images of each part. These images were then employed to construct micro-3D conformation of leather fibers, through which researches on physical and mechanical properties and thermo-heat comfort performance of leather wear were conducted.Comfort performance contains two parts, subjective and objective. Subjective comfort is means touch sensation, pain sensation, temperature sensation and pressure sensation of human skin, and the evaluation of psychological feeling during dressing. Objective comfort includes the factors of garment material, temperature, humidity, weather and wear environmental, which performance is mainly on the factor of performance of materials themselves. As for leather, diameter, cycle band, cluster state, crimping extent and density etc. of fibers have direct impacts on comfort performance, so researches on fiber properties could well present comfort performance persuasively.Although achievements on textile clothes comfort performance have almost been mature across the world, researches on thermo-heat comfort performance is still progressing, which focus on impacts triggered by pressure, structure, sense and environment. And for leather, its analysis remains on 2D stage. Passing through visualization of 3D reconstruction technology has a more direct illustration of material features. Computer image processing technology grows more mature now, and achievements of 3D conformation are increasingly getting skilled, bringing a fresh view to observe comfort performance of leather wear, which is also a compromising direction for researches.Medical means were employed to fix collagen fibers of sheep leather. After slicing, sequenced scan was used to acquire 2D images to analysis differences among diameter, cycle band, cluster state, crimping extent and density of each part. Base on these 2D images, 3D conformations were established accordingly to have a direct observation of fiber shapes with multi-angle. In combination with different parts’ physical properties and other comfort performance, these images helped to identify correlation between comfort performance and 2D & 3D conformation.Conclusions from this thesis were as follows:(1) Three-sultan Ⅳwas confirmed of this dyeing system. Unsaturated polyester resins were used to embed leather samples. In the condition when temperature was room-temperature, reaction time was 2 hours, mass ratio of resin, curing agent and catalyst was 100:1.6:0.5, an optimal performance was got. Repeated experiments indicated that 20 times and 30~40 laps of grinding and polishing depth helped to acquire better images.(2) Analysis of different parts’ fiber diameter varied with different ranges. In the range of 95.82 Pixels ~ 120.35 Pixels, hip and back got the maximum, four limbs was the minimum. As for cross striation, in the range of 13.96 Pixels ~ 17.93 Pixels, abdomen and flank was the maximum, while head and tail was minimum. Four limbs got best fiber bundle state while hip and back was the worst. Abdomen and flank was better than hip and back in crimp degree. Fiber density of each part was 59%, 62%, 55%, 53%and58%.(3) Results showed the differences of properties for each part. As for air permeability, the sequence was abdomen and flank > arms and legs > neck and shoulder > head and tail > hip and back. As for moisture-penetrability, the sequence was abdomen and flank > arms and legs > neck and shoulder > head and tail > hip and back. For thermal insulation properties, the sequence was hip and back > head and tail > neck and shoulder > arms and legs > abdomen and flank.(4) Comparative analysis of 3D conformation and thermo-wet comfort showed that, air permeability was proportional to fiber porosity, fiber bundle state and crimp degree, while inversely proportional to fiber diameter. Moisture permeability was proportional to fiber porosity, and related to fiber diameter and crimp degree. Thermal insulation was proportional to fiber density and diameter, while inversely proportional to crimp degree and bundle state.