Session: Herman & Myrtle Goldstein Student Paper Competition
Wednesday, April 2, 2014
9:45 AM – Noon
Moderator: Renzo Shamey, North Carolina State University
This competition is conducted under the auspices of AATCC's Textile Education Committee. Papers are judged on originality, scientific value, and presentation. First, second, third, and fourth place awards are presented.
2:00 – 4:00 PM
Moderator: Keith R. Beck, North Carolina State University
One Way Sustainability Program
Bryan Dill, Archroma US Inc.
With an estimated six million tons of textile chemicals used annually, the environmental impact of textile processing has become a global concern. Brand owners and retailers are putting more emphasis on the environmental impact of textile wet processes. In response, various industry measures of dye and chemical product and process impact have been developed. The ONE WAY by Archroma methodology takes a systematic approach to the ecological selection of chemicals and production processes. All dyes and chemicals used are screened by product stewardship specialists against more than 15 textile eco-standards to score their toxicological and ecological profiles. It offers process categorization based on environmental focus. The ONE WAY Calculator can be used to assess cost, performance, and environmental profile of ONE WAY products.
A Study of Direct Esterification of Cotton Cellulose with an Aromatic Acid: An Exploration for New Non-Formaldehyde Treatment Process
Gang Sun, University of California, Davis
Polycarboxylic acids will form corresponding anhydrides and then react with cellulose. The anhydride structures are considered as key intermediates in the crosslinking of cotton. However, direct esterification reactions of cotton with an aromatic polycarboxylic acid were revealed and confirmed recently. Such a reaction is important in developments of new cotton wrinkle free finishing agents or potentially new catalysts to replace sodium hypophosphite. In an effort to further understand the direct esterification reactions and its potential applications, we conducted a series of lab and pilot-scale tests to verify reaction conditions and their effects on the treated cotton fabrics. Crosslinked cellulose structures of the finished fabrics were quantitatively evaluated by using FTIR. Fabric properties were improved. This presentation will discuss the findings and applications for cotton fabrics.
Alternative Reduction Method for the Application of Vat and Sulfur Dyes to Cotton Fabrics
Leonard Farias, Cotton Incorporated
Two chemical reduction systems were compared for the application of vat dyes and sulfur dyes. Caustic/hydro systems have been used for a long time as a reduction system in the application of vat dyes to cotton. Although some sulfur dye suppliers provide pre-reduced sulfur dyes, many plants continue to use a caustic/hydro method. Reducing sugars can be substituted for hydro systems with sulfur dyes. The use of liquid hydrosulfite (Reductone) in vat dyeing systems requires refrigeration and storage at 45-50 °F under an inert atmosphere (nitrogen) to insure reducing agent stability. The use of flammable powdered hydrosulfite introduces safety and handling issues. Sodium borohydride is a suitable substitution choice for reduction conditions with vat and sulfur dyes, offering a method for applying pre-reduced sulfur dyes.
Session: Advances in Application Technology
Thursday, April 3
9:00 – 11:45 AM
Moderator: Kanti A. Jasani, Performance & Technical Textile Consulting
Imaging-Based Mote Counting Method
Ming Li, North Carolina State University
The quality of processed cotton is due, in part, to the uniformity of appearance and whiteness of the fibers and resultant fabrics. A key factor in wet processing is removal of colored impurities inherent in the fiber, as well as visible particulate matter. Motes are the most common visible particle-based impurity that are usually present on the surface or physically entrapped among the yarn or fabric interstices. Determination of the number of motes in a given area is time consuming and potentially inaccurate if done manually. A new method of counting number of motes in greige/bleached cotton fabrics using a simple image processing approach is described. Compared to traditional counting, this image processing method has the potential for higher repeatability, accuracy, and speed.
Advancing the Forensic Analysis of Dyed Fibers via Time-of-Flight Mass Spectrometry
Chuanzhen Zhou, Keith Beck and David Hinks, North Carolina State University
Dyed fibers are commonly obtained as trace evidence at crime scenes. Time-of-flight mass spectrometry (TOF MS) has the potential to substantially advance forensic dyed fiber analysis by providing “exact mass” data of dyes and other chemicals present in dyed fibers. Reported are data from two approaches using TOF MS for accurately identifying the molecular formula of dyes. One involves extraction of dye from 100 µg or less of fiber, followed by High Performance Liquid Chromatography – TOF MS analysis. The other is Time-of-Flight Secondary Ion Mass Spectrometric analysis of the surface and cross-sections of dyed fibers without extraction. Both approaches can clearly identify commercially important dyes applied to polyester fibers. This project is part of NC State University’s Forensic Sciences Institute, which will be reviewed briefly.
Incorporated and Performance of Molecular Polyoxometalates in Fibrous Substrates
N. Elizabeth Allen, Cornell University
Combining unique fiber morphologies with self-decontamination technologies can enhance toxin degradation on textile substrates. Co-continuous electrospinning was used to fabricate nanofibrous cellulose acetate membranes with unique, grooved fiber morphology due to the selective dissolution of polyethylene oxide. The BET surface area of these grooved fibers was compared to that of like non-grooved fibers. A self-decontaminating polyoxometalate (POM) (H5PV2Mo10O40) was synthesized, characterized, and used to functionalize both the grooved and non-grooved fibers. The POM-treated substrates were exposed to methyl parathion, a simulant of the chemical warfare agent (CWA) VX, for 24 hours. Methyl parathion degradation was measured and related to substrate properties and morphology. This work contributes to the use of novel fiber morphologies in breathable chemical protective apparel to achieve better CWA decontamination and comfort.
Ultrasound-Enhanced Bioscouring of Greige Cotton: Regression Analysis of Process Parameters
Michael W. Easson, USDA-ARS
Ultrasound-enhanced bioscouring process parameters are examined for greige cotton fabric using design of experiments (DOE). An equation is presented which predicts bioscouring performance based upon a statistical analysis of percent reflectance values obtained from UV-Vis measurements of ruthenium red stained fabrics. Experimental design reveals factor significance using a modified quadratic model. Optimal bioscouring conditions are determined based upon enzyme concentration, process time, ultrasonic power, and frequency.
Caging Antimicrobial Silver Nanoparticles inside Cotton
Sunghyun Nam, USDA-ARS-SRRC
Antimicrobial silver nanoparticles (Ag NPs) applied on textile surfaces are washable, showing lack of durability and ultimately posing a potential environmental risk. In this study, a method to produce a stable, non-leaching Ag-cotton nanocomposite has been developed. Ag NPs were in situ synthesized in the alkali-swollen internal structure of cotton. The electrostatic self-assembly of Ag ion precursors on the deprotonated cellulose and the microfluidic system generated by the microfibrillar channels allowed controlled reduction reaction and particle growth. Consequently, mono-dispersed Ag NPs (12-14 nm in diameter) were produced in the entire of cross-section of the fiber at room temperature within ten minutes. The crystalline structure and tensile properties of the Ag-nanocomposite were investigated using X-ray diffraction and a Favimat tester, respectively.
2:15 – 3:45 PM
Moderator: Nelson E. Houser, M. Dohmen USA
Molecular Engineering of Sustainable Synthetic Colorants
Harold S. Freeman, North Carolina State University
The sustainability of dyes for textile and related applications came to the forefront when it was discovered that exposures to certain azo dye intermediates (aromatic amines) produced bladder cancer in humans. Sustainability determinations included testing of azo dyes and their intermediates for mutagenicity and/or carcinogenicity. While those studies were aimed mainly at risk assessment, the utility of the results in the design of alternatives to genotoxic compounds was also exploited. This presentation provides an overview of studies that pertain to the environmental chemistry of azo dyes. Emphasis is placed on designing replacements for dyes and dye intermediates that raised genotoxicity concerns. As a necessary first step, correlations between chemical structures and environmental toxicity were sought and the resultant information was used in molecular design studies.
Reuse of Hydrolyzed Reactive Dye Bath
Pravir Jha, Advanced Academy for Development of Textile Technologies (AADTT)
In this work, an attempt is made to use hydrolyzed reactive dye bath for coloration of fresh cotton and wool material. Three types of reactive colors, namely Hot brand, HE type, and FN series, were used for the study. Two dyes from each of the three brands were applied on bleached cotton fabric at different shade percentages. The percentage exhaustion in each case was determined by finding the optical densities of the dyed solution before and after application. The exhausted baths were then used for dyeing cotton fabric and wool fiber, at neutral and acidic pH, respectively. The results were analyzed in terms of K/S, color difference, and washfastness. The dyeing effects obtained were quite encouraging with good color depth and tolerable fastness.
Dyeing Cellulosic Knitwear, Woven Fabrics and Apparel by Exhaustion with Novel Reactive Indigo Particle Dye
Jaime I.N.R. Gomes, Ecofoot, SA
Dyeing of cellulosic fibers with indigo dye is based on reduction of the insoluble blue dye to a soluble dye in a leuco form, which is a yellowish color. Oxidation, which can be done by exposure to air, returns the dye to its insoluble form and characteristic color. The problem is that on exhaustion dyeing, mainly for knitwear and garment dyeing, it is not possible to dye uniform colors, due to premature oxidation of the dye. One way to overcome this problem is to dye with the dye in its oxidized form. In our process, a novel dye was developed based on the insoluble indigo color incorporated into particles with reactive groups that give it affinity and fastness. The results for uniformity and washfastness are presented.