Online Analysis of Textile Card Web Density

One area of research at Georgia Tech recently has focused on the measurement of Card-web density. This research is part of a study to spin yarns directly from a card web thus eliminating several processes. A Card-Spinning system has been designed which can quantify the cross-machine and machine direction web non-uniformity using a non-contact web density measurement technique. The web monitoring system for Card-Spinning uses a line scan camera to capture the image continuously and is equipped with an image analysis program, to characterize the web quantitatively, predicting the product quality. A multifunctional graphical interface has been designed for the image analysis program, which can be used to calculate the statistics for the non-uniformity of the card web both online and offline. This would help in characterizing the nature of non-uniformity and to understand the system better before employing methods to improve it. This paper discusses the development and results from the work.

Processing Considerations for Salicylic Acid-Based Polymers

This paper describes some of the processing issues for extruding salicylic acid-based polymer prodrugs into fibers for medical devices. Polymeric prodrugs, in which a drug is polymerized in a degradable polymer that delivers controlled quantity of the drug to a targeted site in the body as the device degrades, are a new approach to controlled release. Hollow fibers were produced by solution spinning. Solid fibers were formed by melt processing. The salicylic acid polymers exhibited shear-thinning behavior. The viscosity exhibited pronounced temperature dependence.

Investigation Into the Utilization of Peanut Fibers in Nonwovens

Peanuts are one of the leading food crops produced in the United States today. One of the problems of peanut production is disposal of the shells, or hulls, of the peanut, which are generally landfilled. The current research focused on obtaining fibers from the shells, characterizing them, and creating nonwoven fabrics containing these fibers, which were also characterized. The fibers obtained ranged in length from 0.6 cm to 6.3 cm, and were generally stiff. Wet laid nonwovens were produced and a variety of bonding methods such as needlepunching and latex bonding were performed. Latex bonding gave the best results, and the resulting fabrics were characterized in terms of strength, moisture, and light penetration, and thermal insulation capability. The fabrics had similar light and moisture penetration properties as some commercially available erosion control fabrics and thus may be suitable for this purpose. The fabrics also retained some heat, and may be suitable for insulation purpose.

Advances in Fabric and Structural Analyses of Pressure Inflated Structures

Novel methods for analyzing the response of air inflated fabric structures are presented. The first method determines the global structural response of air inflated beam and arch structures. It employs a previously developed specialized finite element. The element was derived by minimizing the strain energy potential for a cylindrical membrane deforming about its pressurized state. Through the use of displacement approximations defining the motion of the beam’s cross section, analogous to classical beam theory, the energy principle is reduced to one dimension. However, the effect of the pressure is included in the formulation. Numerical results compare favorably to experimental data for air beams constructed from Vectran®. The second method is based on the micromechanics of plain-woven fabrics. It employs nonlinear kinematics to predict the load-displacement response of a biaxially loaded fabric. Based on the fabric strip model, this method includes the effects of crimp in nonlinear kinematic material behavior and estimates values of effective material properties in tension and shear.

A Stochastic Approach on the Tear Behavior of Coated Fabrics With Interphase

A stochastic approach, the Ising model combined with Monte Carlo simulation, is employed to study the process of a tongue tear process of coated fabrics. The complicated mechanisms involved can be realistically simulated with a relatively simple algorithm. The important factors, especially the interphase between the coating and the fabric, influencing the tear behavior, formation and failure of the del-zone can be represented by the corresponding coefficients in an energy expression of the system. The results of parametric studies are in good qualitative agreement with the behavior of real systems, indicating the usefulness of this approach in the studies of similar interfacial phenomena.

Finite Deformation Micromechanical Analysis of Textile-Reinforced Plastics

Nonlinear elastic stiffness behaviors of plain-weave textile-reinforced composites are considered in this work by modeling finite deformation effects at two scales: (1) at the fiber diameter scale within yarns (~10 microns); (2) at the yarn diameter scale within woven textiles (~1000 microns). To capture the effect of heterogeneous microscale stress and strain fields, symmetric, conjugate, stress and strain measures are first established. A transversely isotropic hyperelasticity model is then presented for modeling finite deformation behaviors of yarns. After the free parameters of this model are estimated using unit cell analysis at the fiber-diameter scale, it is then incorporated into plain-weave textile unit cell model. The textile mode is then subjected to finite strain deformation controlled loading to quantify nonlinearity in stiffness behaviors.

Weaving Loom Integration in Textile Enterprise

Weaving technique represents the development of textile industry. After 25 years of open gate and reform of industry construction, textile manufacturing in China has been developed to a higher level. China had imported many modern weaving machines from Italy, Switzerland, Belgium, Japan, and other countries. The domestic textile machine manufacturers and research institutes developed and manufactured many kinds of shuttleless looms. According to the statistical calculation, the total number of shuttleless looms is more than shuttle looms in use in China currently [1]. The wide use of the shuttleless loom demonstrates a strong technical support to the modernization of textile industry in China. These kind of shuttleless looms are equipped with advanced mechanisms like electronic let-off motion, electronic shedding motion, computer based monitoring, electronic dobby and jacquard machine. They are modern textile machines. Due to the labor denseness of the textile industry and unbalanced development of information technology (IT) in China, the manufacturing organization mode of textile is still old fashioned. Modern machines did not get the most economic and technical benefits. This situation was called “Automation Island”. In this paper, the author will describe his research in the integration of weaving machines through a local net. In the author’s project, which is being supported by the Natural Science Foundation of Zhejiang in China, a research team tries to reform the original computer-based loom controller. The required hardware modification and software programming was added. All looms of the workshop were linked to a central control computer through PROFIBUS to make a local net. Now weaving information of every single loom can be monitored through this central computer. Weaving machine integration is very important textile enterprises. There are a lot of applications using this technology. Web-based (mass customization, MC) customized produce is the future of advanced manufacture. An integrated workshop is a good platform for the enterprisers to expose their business to worldwide market. In this article, the author will discuss effort in this area, including experiments and results.

Enhancing the Acoustic Absorption Properties of Needlepunch Nonwovens

This study encompasses the initial development of new acoustic absorbing materials for use in aircraft interiors. Current needlepunch nonwoven materials used as acoustic absorbers were characterized using three methods, the measurement of acoustic absorption coefficient, poroelastic parameters, and process factors. In order to show true improvement in the sound quality of an aircraft, two factors are considered: weight loss and noise reduction. An ideal material solution would include reducing the weight while also reducing the noise level. Although the attempt is to do both, a realistic goal for a new material is to reduce weight while maintaining current acoustic absorption values. This research is the initial characterization and development work for the formation of a new acoustic sound package for use in aircraft interiors.

The Tensile Properties of Three Dimensional Air Textured Aramid Reinforced Composites

Air-textured aramid yarns (ATAY) and regular aramid yarns (RAY) were used in this study to fabricate 3D orthogonal woven composites. The composites were tested in warp, weft, and 45° directions to determine the engineering constants of the composites. The ATAY composite had a much lower fiber volume fraction than the RAY composite due to the bulkiness of the textured yarns. With the same fiber volume fraction, the ATAY composite had a slightly lower tensile strength and modulus, but a 120% higher in-plane shear modulus, than the RAY composite. Unlike the RAY composite that demonstrated a brittle failure, the ATAY composite failed in a ductile manner with multiple diverting cracks propagating during failure. The ATAY composite had a much higher yield point in the 45° direction tensile test and a much higher softening point in the warp direction tensile test than the RAY composite. The loop entanglements of ATAY are responsible for all the improvements observed in this study.

Compact Spinning: A Critical Review

Compact spinning is a novel concept generated through re-engineering of established ring spinning process by attaching a pneumatic zone to existing ring spinning machine. Compact spinning achieves a remarkable improvement in yarn quality and yarn structure through better utilization of fibre properties. The advantageous yarn characteristics provide better opportunities for cost savings in subsequent processing stages. Another interesting aspect is the possibility of developing new textile products using compact spinning. There are three major manufacturers in the field of compact spinning machines namely, Sussen (Elite spinning), Rieter (Comfor spin), and Zinser (Air-Com- Tex 700). First launch of Elite spinning machine in India faced a setback due to few practical problems like inadequate lubricating film on ring (does not allow the maximum spindle speed to be achieved), higher maintenance cost, higher labour cost and apron clogging due to accumulation of fly. However, with further developments compact spinning will certainly be the future of ring spinning, on account of its higher productivity and yarn quality.