Sensors and actuators featuring biomimetic properties, with linear and angular resolution, good compliance and long term biostability are in growing demand for applications such as synthetic muscles, sensor equipped limps and other bio-engineering designs. Recent research papers have demonstrated that insulator materials coated with polypyrrole or polyaniline and combined with various dopants can achieve piezoresistive and dielectric properties, enabling the detection and displacement of local strains in polymer sheets, textile fibers and fabrics. It is known that composite films made from layers of carbon black (CB) filled polyvinylindene fluoride (PVDF) and high density polyethylene (HDPE) films provide stable piezoelectric behavior in the temperature range from 20 to 140 oC and low tensile loss on exposure to moisture and hydrolytic conditions. However, to date the literature contains no references to the use of this particular polymer system in fiber or textile form. Moreover, since the resistivity of such composites can be quantitatively specified by selectively localizing CB in one polymer phase or at the interface of an immiscible polymer blend, it was hypothesized that bicomponent fiber spinning might lead to similar piezoelectric properties within individual fibers. This research study was therefore aimed first at determining whether a blend of PVDF and HDPE polymers filled with CB could be melt spun and drawn into a series of composite or bicomponent fibers using a laboratory extruder and drawing machine. This was accomplished successfully with loadings of CB varying from zero to 27.7% by weight. The second goal was to determine the weight fraction of CB that should be added to PVDF / HDPE composite fibers in order to optimize their electrical functionality and piezoelectric performance. Analysis of the deformation of the as-spun and drawn fibers in their longitudinal direction during charging and discharging was conducted in a novel piezoresponse force microscope (PFM). It demonstrated that increasing the CB content also increased the ferroelectric hysteresis and piezoelectric constant of the composite fiber up to the percolation threshold of 20.7% of CB by weight. The CB was selectively located in the HDPE phase, resulting in a significant loss of crystallinity in the HDPE phase. At the same time, the PVDF phase was transformed from a non-polar to a polar form. The optimum spun and drawn composite piezoelectric fiber measuring 120 microns in diameter contained 56/32/12 PVDF/HDPE/CB by weight. Under the electric stimulation of a few volts it was predicted to be capable of producing a tensile force of about 2 x 10^-2 N for a 350 mm long fiber with 1 mm 2 cross-sectional area. It is anticipated that a bundle of such piezoelectric fibers measuring 26 mm² in cross-section could generate the force of 0.5 N required to complete flexion of a human distal interphalangeal (finger) joint. The incorporation of CB filled HDPE produces a conductive matrix phase within these bicomponent fibers, which acts as an electrode around the PVDF regions, facilitating a more uniform distribution of the piezoelectric charge within the PVDF phase. These encouraging results bode well for future piezoelectric fibers, which have both rapid electromechanical response and good biostability. Additional larger scale tests are recommended to evaluate the efficiency of these novel biomaterials for use in biomedical and electrotextile end-uses.

This research involves the application of hydroentangling technology as a means of significantly improving knitted fabric properties. In the past, various efforts have been made, directed at improving the dimensional stability and physical properties of woven and knitted fabrics through the finishing technique of hydroentanglement. In such applications, warp and filling fibers in fabrics are hydroentangled at crossover points to effect enhancement in fabric cover. The process parameters of hydroentangling are investigated and optimized to achieve desired results. Potential benefits include enhanced fabric durability, stability, and appearance.

The purpose of the research has been to investigate how merger and outsourcing activities impact the way productivity is measured on five categories of company resources: human, physical, knowledge, capital, and infrastructure resources. This research involves: an assessment of productivity measures with the goal of determining which resource category are key areas to monitor after merger activity, an evaluation of profitable textile mergers with the goal of delineating the execution of the merger strategies, an analysis of the effect of increased outsourcing on productivity growth with respect to the textile industry, and an evaluation of the adequacy of productivity measures in representing the economic competitiveness of the US Textile Industry. For the sample of textile companies, merger activity impacts the productivity of capital and knowledge resources the most. The most common strategies employed during successful textile mergers targeted the improvement of: corporate structure, product differentiation and speed to market. The influence of outsourcing on productivity growth in the textile industry was found to be negligible when comparing productivity measures that include and exclude outsourcing. In order to get a better understanding of competitiveness, companies are not looking solely at productivity, but are pairing productivity with other measures mainly profitability measures. Of all the resource categories, the productivity of knowledge resources is the leading contributor to competitiveness. However, one difficulty is that knowledge resources are also the category for which there were not concrete measures productivity that denote how well this resource was being used.

Over-end unwinding has been proved to be the most optimal process to transfer yarn from one package to another in order to improve the quality and the characteristics of subsequent processes like warping and weaving. It is the highly non-linear behavior of this unwinding process that the variation in the quality of the final product is found and if this behavior is not controlled, the variation becomes more pronounced. This non-linear behavior should be well understood to select the optimum process parameters for a given operation and subsequent processing. This research study is done to analyze the effects of various process parameters on the tension distribution and balloon profile and to experimentally validate the mathematical model set forth for predicting the behavior of over-end unwinding. The materials used for the experiments are Polyester multifilament yarns of different linear densities (70, 270 and 500 denier). The variables used for the study purpose are Unwinding Speed, Mass Linear Densities, Package Diameters, and Guide-eye Distances. Balloon images are captured using a high-speed camera and the images are synchronized with the tension readings. Since three levels of each variable are used, 81 numbers of tests are conducted. Accordingly, the influence of changes in variables as well as the direction of unwinding (front-to-back or back-to-front) is seen for the tension distribution and balloon profile. The results of the experiments are compared with the theoretical predictions. In agreement with the theory, increase in the balloon height causes increase in tension. Also, the reduction in balloon count is accompanied by the increase in tension. Highest possible tension is seen with single balloon formations. With the same balloon count, an increase in unwinding speed gives rise to increased tension.

ZAVERI, MITUL DILIP. " Absorbency Characteristics of Kenaf Core Particles " (Under the direction of Dr. Behnam Pourdeyhimi). Chopped Kenaf Core (2 " to 4" in length), obtained from Greene Natural Fibers ? a company located in Snow Hill, North Carolina, was ground into very fine particles (below 1 mm) and categorized into various size ranges. The ground particles were tested for water absorbency and the optimum particle size, giving maximum absorbency, was determined. Experiments revealed that Kenaf Core of size range 106 ? 425 microns gave the highest water absorbency at saturation, up to 12 times its weight. The 425 ? 840 micron range was the next highest and it absorbed water up to 10 times its weight. Factors leading to this optimum particle size range were determined, the absorption mechanisms taking place were studied and experimental analysis was done to prove the results obtained. Scanning Electron Microscopy (SEM) images were also taken to understand the shape and profile of the granular particles in fine detail. Various chemical treatment and refining experiments were carried out on the highly absorbent particle sizes (106 ? 840 microns) to enhance their bonding properties and to make handsheets from them. The highly absorbent Core particles were treated with NaOH in water bath at 90 º C, Cooked with NaOH and Na2S at 170 º C in a bomb reactor and treated with water in a water bath at 90 º C, all for 3 hours. Handsheets were made from the chemically treated particles to determine if there was sufficient bonding between them. To enhance the bonding further, the particles were refined in a blender for one hour. The effect of chemical treatment and refining on the absorbency properties of the Core was determined. SEM analysis of the particles was done to visualize the fibrillation caused due to refining. Handsheets were made with a blend of hardwood and highly absorbent (untreated and water treated 106 ? 840 micron) refined Core particles with 50 ? 70% of Kenaf Core in them. The absorption properties of these handsheets were determined and compared with the absorption of a handsheet made from fluff pulp (same basis weight). As the final step, the handsheets made from a blend of kenaf core and hardwood pulp were sandwiched between a pair of 17gsm lightly calendared polypropylene spun bond fabrics.

The purpose of this research has been to explore the role of agent certification in the process of global sourcing. While some research has been done in the area of exporter-intermediary relationship, little has been done to study the importance of buyer-agent relationship and how the process of agent certification could strengthen that relationship. Global sourcing has played a vital role in the existence of textile and apparel industries across the world. With the increased advancement of developing countries and the numerous advantages that these countries possess, developed countries, such as the United States and countries in the European sub-continent, rely heavily on global sourcing to remain competitive in the global marketplace. Due to numerous barriers to global sourcing such as language barriers and inability to check sources, companies have found it useful to source through agents. These agents act as the facilitators between the sources and the buyers. With the advent of Internet and e-commerce, online sourcing has come into picture. Although the transparency in terms of sources and buyers on the web and their processes has increased and organizations are thinking of certifying sources, the role of agents' sill exists. A total of 30 agents and apparel-manufacturing buyers were interviewed to assess the feasibility and role of agent certification in the global sourcing process. While the specific items to be certified were not confirmed, both types of subjects agreed that agent certification would assist in the transactions in the buyer-agent relationship. It was found that small and medium-sized buyers would find agent certification more useful than large-sized buyers because of small-size buyers' limited resources and potential to find trusted agents.

In order to better understand the changes and trends in the increasingly competitive dynamics of global textile complex, this research focuses on analyzing the rate of change in country of production origin for fiber, yarn, fabric and end-use products in the past decade. By using the model of textile product complex as framework, the data presented in this research paper were firstly collected from various data sources, such as the Fiber Economics Bureau, ITMF, ICAC, Textiles Intelligence, CIRFS, and WTO as well. The data were then validated to ensure its integrity, which represented a significant stage in the process. Finally, the data were analyzed and conclusions were drawn based on the obvious trends in the data. This research offers a practical interpretation of the direction and magnitude of changes in worldwide textile and apparel production. Meanwhile, it provides an outline of the relationships between textile trade and production, as well as the relationships between production and employment. In addition, the findings from this study will show the direction for global sourcing of textile and apparel products.

Master of Science / Department of Apparel, Textiles, and Interior Design / Melody L. A. LeHew / The Textile and Apparel (TA) industry has become increasingly criticized for its massive environmental pollution through unsustainable production and distribution. In addition, key stakeholders are equally recognizing the need for cleaning up the industry. However, TA manufacturers, brands, and retailers need to be more aware of the necessity of sustainable production and distribution. At the same time, TA consumers need to be more aware of the necessity of sustainable consumption, care, and disposal of clothing. The purpose of this study was to investigate whether social networking sites (SNS) have any potential to increase consumer awareness of TA-related environmental sustainability issues. The specific research objectives were to investigate 1) whether engagement with TA-related environmental information in a SNS platform (i.e., Facebook) enhanced participants’ knowledge of TA environmental sustainability issues; 2) which format of TA-related environmental information sharing stimulated a higher level of SNS engagement and greater knowledge change; and 3) which content of TA-related environmental information sharing stimulated a higher level of SNS engagement and greater knowledge change. One group pretest-posttest experimental design was used, and mixed method approach was employed. Participants responded to a study-specific textile and apparel environmental sustainability knowledge (TAESK) scale before and after a Facebook experiment. The experiment included engaging with TA environmental information for a two-week period in a Facebook page. The researcher was the creator and administrator of the page. Quantitative data analysis included descriptive statistics, the Wilcoxon Signed-Ranks test, and multiple regression analysis. Qualitative analysis included conventional content analysis techniques. Findings from Wilcoxon Signed-Ranks test indicated that the experiment increased participants’ knowledge of TA environmental sustainability significantly (Z= -5.274, p< 0.001). Descriptive statistics revealed that video and infographic-type posts stimulated greater participants engagement than weblink (i.e., text based) posts. Likewise, participants were engaged with water and waste-related content of TA environmental sustainability more so than chemical and energy related content. However, the multiple regression analysis which was employed to identify the weighted influence of different formats and content of TA environmental sustainability information towards knowledge gain, provided limited information. This exploratory study provided some support for the usefulness of incorporating SNSs as part of an educational strategy by TA brands and policymakers advocating for sustainable TA production and distribution. Such a strategy may be one way to increase consumer awareness. Also, the findings of this study may motivate TA educators to weigh the potential of SNSs in teaching and learning activities related to TA sustainability issues.

Given the severe global competition and the manufacturing challenges, retaining competitiveness in the textile and apparel (T&A) industries has become crucial for manufacturers. To achieve this, although historically manufacturers have been regarded as mainly production orientated, a number of them have occupied a primary intermediary position by applying the mechanisms of industrial upgrading and instituting new product development (NPD) in their businesses together with the synergy of alliances and networks. This has enabled the manufacturers to provide various products and services to international buyers. The Taiwanese T&A manufacturers can serve as a good example. They have managed to retain their competitiveness in the global industry for the last half century by continuously evolving their businesses and acquiring extensive capabilities. To achieve competitiveness in the T&A sectors, strategic planning that can lead to competitive advantages is required. NPD has emerged as a source of business competitiveness and its success determinants can lead to competitive advantages. Supply management, particularly partnering relationships, is crucial to manufacturers’ competitive advantage, since no single firm can possess all the necessary resources and capabilities. Against this background, this study has constructed a research framework, in line with the resource-based view (RBV) and transaction cost theory (TCT), in order to explore how competitive advantages can be achieved, which can lead to manufacturers’ competitiveness. An in-depth case study of a representative Taiwanese manufacturer has been employed and examined. The selected Taiwanese T&A manufacturer has acquired resources, various (dynamic) capabilities and knowledge through its NPD process, resulting in core competences and sources for competitive advantages. It has become a lead firm in its supply chain/network, deploying a variety of partnering relationships in order to conduct NPD activities strategically, and has vertically integrated T&A NPD. This has allowed it to provide an increasing variety of new products and services, in order to serve a wider range of customers, thus continuously acquiring business opportunities in dynamic markets. This study has found that the manufacturers in the T&A industries can adopt more proactive strategic modes in NPD activities, to enhance NPD outcomes and their relationships with buyers. It is important for manufacturers to acquire crucial and complementary resources/capabilities through strategic networks, developing alliances to strategically plan and implement NPD. Operational relationships need not only to be viewed in relation to their immediate cost reduction benefits, but also to be extended to longer-term collaborations, in order to achieve competitive advantage deriving from evolving products and cost benefits based on a holistic and strategic view of the business.

The purpose of this study is to examine the effects on U.S. textile and apparel imports of the quantitative restrictions imposed under the Agreement on Textiles and Clothing (ATC) (1995-2005), the post-ATC U.S. safeguard quotas on 21 categories of Chinese textile and apparel products (2006-2008), and no quantitative restrictions on U.S. textile and apparel imports (2009-2010). Data were sourced from the Office of Textiles and Apparel (OTEXA) in the U.S. Department of Commerce, the GeoDist dataset from the Centre d'Etudes Prospectives et d'Informations Internationales (CEPII), and the United Nations Commodity Trade (U.N. Comtrade) database. In this research, three gravity equations were developed and estimated based on the existing gravity model. The first gravity equation was estimated to assess the effects of the independent variables commonly included in gravity models on the total value of U.S. textile and apparel imports from 187 exporting countries with a scaled dependent variable and from 177 without it. The result of the first gravity equation indicated that distance and the per capita GDPs of the exporting countries, exchange rates, and the total GDPs of the exporting countries are statistically significant and have the expected signs in the model with the scaled dependent variable. The second gravity equation was estimated to access the overall effect of the presence or absence of quotas and VERs on U.S. textile and apparel import quantity from the 187 exporting countries. The results from the second gravity model showed that the presence or absence of quotas or VERs is significant and has an unexpected positive sign because the United States tended to impose quotas and VERs on textile and apparel products that it imported in large amounts. The third gravity equation was estimated to assess trade creation and trade diversion effect of the quota and VER levels of U.S. textile and apparel imports with separate equations by product types considering the endogeneity by applying instrumental variables. The result from the third gravity equation showed that the quota and VER level is significant for fabric, apparel, and made-up products with expected signs but the variable is not significant for yarn products. These findings suggest that U.S. textile and apparel imports from the exporting countries limited by quotas and VERs on U.S. textile and apparel imports increased more than rest of world (ROW) imports from those countries as the quota and VER levels on U.S textile and apparel imports increased. Therefore, trade creation occurred between the United States and the exporting countries as the total SME quota or VER levels on those imports increased during the ATC and safeguard period. However, these findings show the demand of yarn as intermediates does not increase much in the United States; therefore, the increase of the total yarn quota or VER level has less of an effect on the yarn imports than other product types. / Ph. D.