Table of Content - JFBI 6.4

Lignin, the second most abundant biopolymer on earth, has the potential as a low cost and renewable precursor for carbon fibers. By creating lignin carbon nanofibers for lightweight structural composites for automobiles and functional applications as electromagnetic shields, the value of lignin will be enhanced. Under the Lignoworks Biomaterials and Chemicals Network program, we demonstrated the feasibility of producing carbon nanofibers from softwood Kraft lignin by electrospinning and heat treatment. The morphological, mechanical, and electromagnetic properties of the lignin carbon nanofiber were characterized. Results showed 10 times increase in strength for the lignin random nanofiber mats after carbonization. Alignment of fibers further improved the mechanical strength. By doping the lignin polymer with carbon nanotubes and functional nanoparticles such as magnetite, we demonstrated the feasibility of translating the strength and electromagnetic function respectively to the lignin nanofiber assemblies. The encouraging results demonstrated the potential of lignin as an engineering material thus establishing a pathway for adding values to the abundantly available lignin.

Material with negative Poisson's ratio is a kind of new structural material with special physical properties and geometric structure, which undergoes a transverse expansion when stretched in longitudinal direction and a transverse contraction when compressed. Compared with common textile materials, auxetic textile materials are significantly different in terms of thier structures and properties. Thereof, reviews on auxetic materials of foam, polymer and textile materials were investigated, and the mechanism of the dilation property was analyzed and obtained in this paper. It is found that these auxetic materials are dependent on the microstructures with reentrant structures or rotating structures. The analysis of the structure of materials with negative Poisson's ratio can contribute to the new textile material technology and new functional textile products, such as magnetic-shielding fabrics and water-repellent/wind-proof fabrics. It is also helpful in infrastructure, aerospace engineering, biomedical engineering and environmental engineering.

"Smart textiles", also known as electronic or e-textiles contain embedded sensors capable of monitoring vital signals such as ECG, EMG, respiratory behaviour and are usually fabricated using rigid semiconductors. In this study, we developed a flexible Physiological Sensing Belt (PSB) by embedding silicone rubber/carbon black/conductive carbon layer coated Polyvinylidene Fluoride (PVDF) film between the elastic textile bands for monitoring respiration and the movement of thigh muscles. With an average peak-to-peak interval of 3 sec, the respiration rate could be evaluated to be 20 min-1. We also developed a novel hybrid sensor using PVDF and Thermoplastic Polyurethane (TPU) electrospun nanofiber webs stacked on each other and capable of measuring both static and dynamic pressure simultaneously within all frequency ranges. Based on the samples used, we were able to measure the walking speed of the subject at 4, 336 steps/h and 0.693 m/step at the speed of 3 km/h and with 6, 656 steps/h and 0.751 m/step at the speed of 5 km/h. Overall, when compared to the existing commercially available pressure sensors, the PVDF and TPU nanofiber web based hybrid sensor developed in our study has advantages of high sensitivity, nanoscale thickness, lower hysteresis curve in pressure-capacitance, and can be easily converged with any fabric or textiles.

Liquid flow through fibrous materials is important in a diverse range of applications. The prediction of flow through fibrous materials is influenced by a variety of factors and has been recognized as a favorite topic of research in recent years. Capillary flow through fibrous materials takes place by two subsequent processes, known as wetting and wicking. Wetting of the material is the initial process, followed by wicking or flow through its capillaries. In high temperature and high humidity conditions, wicking through a textile fabric plays a very important role in maintaining the thermo-physiological comfort of the wearer by transferring the sweat from the skin to the outside surface of clothing. Prediction of the moisture transmission properties of fibrous materials is useful to characterize clothing comfort and it helps in designing textile fabrics with specific requirements. A variety of mathematical models have been proposed in order to understand the liquid flow characteristics of textile fabrics. Flow through capillary tubes and flow through porous structures have been the two main approaches taken by researchers in order to model the capillary flow through fibrous structures. This paper reviews the relevant research in the area of liquid moisture transmission through fibrous materials, followed by experimental verification of some predictions using some of the developed equations. This experimental verification was undertaken by the authors.

The purpose was to focus on the correlation between color combinations of clothing and aesthetic responses. In this study, four levels of contrasting colors were combined in a two-piece suit as stimuli. Behavioral and electrophysiological data were recorded during the course of aesthetic evaluation. Results showed that the higher the contrast of color, the less attractive the clothing is. The early P200 (P2) components were very remarkable in the frontal, central and parietal areas, and the larger amplitudes were evoked for less attractive color combinations. The late P300 component plays a critical role in the decision-making aesthetic a?àrmation. The findings in the current research implied that the P2 and P300 can be viewed as the landmark components for aesthetic response of clothing colors.

In order to improve the accuracy and speed of beat-to-beat heart rate estimation, a Segmented Dynamic Time Warping (SDTW) algorithm based on Ballistocardiogram (BCG) signal was presented. The beat-to-beat heart rate obtained through this algorithm was evaluated using 20 healthy subjects with synchronized lead I ECG as standard. The mean bias between JJ and RR interval was 0.2 ms and the confidence interval of 95% was ?à19 ms. It indicates that the obtained beat-to-beat intervals are in better agreement with that of ECG. The mean relative error and matching time for heart rate estimation with the algorithm were 1.37% and 0.77 s, respectively. The results were superior to that of the traditional template matching algorithms. It establishes the foundation for heart disease monitoring based on BCG signal.

Household CO2 emissions are gaining more attention from researchers in recent years. Domestic washing is an important household routine and one of the main sources of household CO2 emissions. In this paper, Consumer Lifestyle Approach (CLA) was used to quantify CO2 emissions from domestic washing. An investigation of 493 families, from 16 cities out of 8 provinces in China, was held to study the five main household characteristics including the demographic composition, living condition, family income and expenditure, education level and most importantly, laundry habit. The relationship between domestic washing characteristics and CO2 emissions is concluded from multi-variable linear return analysis. The results show that family's washing frequency as well as washing machine's e?àciency and capacity are major factors which affect CO2 emissions. Other factors such as per capita living space, family working population and education level also have an influence to a certain extent.

Excessive breast movement causes breast discomfort, pain and sagging. Previous research has shown that sports bras can support the breasts and reduce breast movement during different activities especially running. However, so far, no published research has studied the design of shoulder straps from a biomechanical modeling perspective, for improving the performance of sports bras. In this study, biomechanical models of shoulder straps with different widths and in different positions on the shoulder have been built, based on the assumptions that the behavior of shoulder straps is similar to that of springs and the front shoulder strap is aligned with the body. The results show that wider shoulder straps are more effective in reducing the breast forces, and the location of the shoulder straps on the shoulder affects their performance in controlling breast movement. This provides a theoretical basis for optimizing the design of shoulder straps to produce more effective sports bras.

Pants fit have always been a problem in China's pant market. To qualitatively improve how well pants fit consumers, we analyzed the lower body shapes of 179 young women from an anthropometric aspect. We first used a 3D measuring method to obtain 85 measurements related to lower body shape. Then, by applying principal component factor analysis method, we used 7 principal components to describe lower body shape. The first 2 factors, heavy-thin factor and abdomen-hip factor, had the highest cumulative contribution rate, 40.475%. Therefore, the hipline of the first principal component and the abdomen-hip di?erential of the second principal component were used as 2 key indexes to classify the lower body into 9 types. After using both the interior extrapolation method based on interval division and the k-means cluster method to further classify the lower body shape, we concluded that the former is more suitable. Therefore, we classified lower body shape into 9 types, the coverage of which reached 80.45% of the total samples. By taking both the degree of stoutness of the lower body and the di?erence of abdomen-hip shape into consideration, this classification can provide a theoretical basis for pants size optimization to improve pants fit in the waist, abdomen, and hip portions.

General studies on individualized pattern making were reviewed. A computerized method of designing high-value-added apparel was developed using three-dimensional data for an individual. In our system, the grainline and cutting line were set taking into account the shear limit angle of the cloth material. Skirts, pants and upper garments with sleeves were made using our system. Individualized clothes were successfully made using our program.