Textile Research Journal

Fluorocarbon (FC) coatings are applied to poly(ethylene terephthalate) (PET) fabrics by ion beam sputtering of polytetrafluoroethylene (PTFE) under different conditions. The range of the adhesion work of the coated fabrics is 5-75 10^-3N.M^-1 . After a washing and wearing test, most of the original coating grains remain on the fabrics, exhibiting good hydrophobicity. From XPS and ATR-FTIR analysis and property experiments, the adhesion work decreases with increasing energy due to increased fluorine content in the coatings, while it basically increases with increasing pore diameter and porosity of the specimens, probably due to the decrease in the real water-coating contact areas and roughness. For most of the just-coated specimens, no yellowing is observed due to high fluorine content. The coated fabric generally exhibits the original moisture permeability of the uncoated fabric because the PC coating covers only the fiber surfaces and most of the original pores in the fabrics remain.

A central idea involved in the design of a dynamic system is the modeling and manipulation of that system. By applying physical laws to a specific system, it is possible to develop a mathematical model that describes the system dynamics. Because a model must be a simplification of reality, there is a great deal of creative art in constructing models. This paper presents a good approach to simplifying a whole roller carding system. It proposes a novel technique to obtain a corresponding single degree of freedom model estimated from a high-order system. This model provides a computationally efficient and conceptually simple algorithm, which for system design purposes yields an appropriate estimation of a high-order linear system.

The response of a fabric to applied forces normal to its plane is known as fabric compres sional behavior. It is one of the important properties that determine fabric performance in many applications. A system used to measure fabric compressional characteristics, online is pro posed in this paper. A controllable nip formed by a pair of rollers is employed to apply compressional deformation to a moving fabric while the compression force and displacement are continuously recorded. The influence of various system parameters on the sensitivity of the system is analyzed. An incremental differential algorithm is used to calculate the pressure- displacement relationship from the measured force-displacement data from the online system. A number of woven and nonwoven fabrics are evaluated using the online measurement system as well as other commercially available fabric compression testers, and compressional char acteristics obtained from the online measurement system compare well with the same param eters measured by the other compressional testers.

To improve the dimensional properties of wool fabric, two kinds of silicone polymers are applied to plasma pretreated wool. With this treatment, hygral expansion increases slightly but still remains smaller than that of silicone treated wool without the plasma pretreatment. The wrinkle recovery angles of wool increase with the treatment, and the values of fabric treated with plasma and silicone polymers are higher than those with no plasma pretreatment. In addition, the harsher handle imparted by plasma modification is improved with silicone treatment. The results show that the plasma pretreatment modifies the cuticle surface of the wool fibers and increases the reactivity of the wool fabric toward silicone polymers. Therefore, the combination of plasma and silicone treatments can improve the dimensional stability, wrinkle resistance, and performance properties of the wool. Surface smoothness of the treated fabrics as measured with a new evaluation system shows good correspondence with results from a KES-FB4 surface tester.

In this work, we describe chitosan-poly(acrylic acid) (PAA) fibers formed at the interface of aqueous solutions by means of polyion complex (PIC) formation between chitosan and PAA. We examine the spinning conditions, tensile strengths, and load-extensibility curves of the chitosan-PAA PIC fibers. Chitosan-PAA fibers are spinnable by gravity and by wet spinning in ethanol. The resulting chitosan-PAA composite fibers are water-insoluble, and the highest tensile strength is 20 kgf/mm ² using 1.0% chitosan and 1.0% PAA. From the load-extensibility curves, chitosan-PAA fibers exhibit higher softness and toughness than chitosan-gellan fibers, as we previously reported. Thus, the chitosan-PAA PIC fiber is a new composite fiber composed of a polysaccharide and a vinyl polymer.

Wool fabrics with a deodorant function are prepared by acid mordant dyeing with copper(II) nitrate. The effects of pre- and after-mordanting are examined for C.I. Mordant Yellow 3 and C.I. Mordant Red 17. Carboxylate groups in the wool fibers and the dyes work to fix copper ion with the deodorant ability against mercaptan. The elimination of mercaptan from the air by the mordant dyed fabrics is measured in a Teddler bag. Fabrics untreated or dyed without mordanting show no deodorant ability, but those pre-mordanted or pre- and after-mordanted show considerable deodorant ability. By controlling the pH of the dyebath to about 4, dye and copper ion uptake of the fabric is optimized and the deodorant ability is also optimum.

Dimethylimidazolidinone/lithium chloride (DMI/LiCL) is shown to be an effective solvent system for a variety of celluloses, including the high molecular weight cellulose of cotton, when a swelling pretreatment in sodium hydroxide is incorporated. DMI/0.5% LiCl is suitable for use as a mobile phase in gel permeation chromatography to determine the molecular weight of cellulose. The results of using the DMI/LiCl solvent system to determine molecular weight parameters (number-average, weight-average, and peak mo lecular weight) of a variety of celluloses (cotton, rayon, tencel, linen, ramie, flax, kenaf) are reported.

This paper presents a new spinning system, a kind of twist draft spinning in which the withdrawal tension in a yam being spun out is used to control its count. This system produces the yam directly from a large mass of fibers in a pot, can spin even low quality fibers that are difficult to spin with modem spinning systems, and is able to keep up with small-scale production of functional yams made from special materials. The spinning process is analyzed and the relation between the yam properties and the fiber properties is revealed. This relation is a valuable tool for designing properties of yarns spun with twist draft spinning. Several functional yarns of a special material are also spun with this system.

The surface structures of activated carbon fabrics and their precursors are examined by scanning force microscopy and scanning tunneling microscopy. Results indicate clear dissim ilarities in the characteristic surface structures of both activated carbon fabrics prepared from different precursors of regenerated cellulosic fibers. The surface structure of these fabrics is resolved over a larger area (2 X 2 μm), showing that the distance between peaks and valleys is larger for one activated carbon fabric (V900) prepared from regular viscose rayon fiber precursors than for another (P900816) made from polynosic fiber precursors. In other words, the BET specific surface area and total pore volume are larger for the former than for the latter. Resolution over (8X8 nm) areas confirms that the surface of the activated carbon fabric develops a microporous structure. The BET specific surface area tester confirms data for the high specific surface area and total pore volume of activated carbon fabrics.

This work continues our study of woven fabric buckling and provides generally analytical results on the buckling of a woven fabric sheet subjected to simple shear along the direction making an angle, θ(0° ≤ θ < 90°) say, to the warp. The buckling direction is related to the angle 0 and the critical amount of shear. As an illustration, the curve of the buckling direction angle versus the amount of shear for θ = 30° is plotted. Out-of- plane fabric buckling is possible, and only a flexural buckling mode can occur. The buckling condition for the flexural mode is also obtained and, as an illustration, a curve for 0 = 30° is plotted. This work also provides foundations for numerical methods to simulate KES shear buckling for fabric.

In situ generation of copolyesters of PET, followed by test tube screening with a textile dyestuff under mild conditions, produces a rank ordering of dye uptakes mimicking that obtained with independently produced copolymers and with (in some cases) textile dyeing of polyester fibers. From these results, we find that PEG is a generally superior diol polyester modifier, that adipate is superior to the lower molecular weight succinate and the higher molecular weight dodecanedioate, and that adipate-PEG combinations are highly effective at improving PET dyeability. The strategy of incorporating diacid modifiers into the polyester during melt polymerization, then incorporating diol modifiers by means of alcoholysis, appears to be an effective means of generating a large library of modified polymers in a relatively short period of time.

This research is a comparative study of the structural and physical properties of ring, rotor, and friction spun yams and an attempt to explain the differences in their physical properties on the basis of yam structure. Results show that the ring spun yam exhibits the highest fiber migration, followed by rotor spun yam, and friction spun yam with the least. A higher migration factor corresponds with a higher yam breaking tenacity. An analysis of packing density shows that the fibers for the rotor yam are located most densely near the yam center, while the friction yam has the highest density of fibers near the yam surface. The ring spun yam has a moderately uniform distribution of fiber packing density. The experimental results on fiber arrangement near the yam axis show that the friction spun yam has the highest rupture elongation due to the skewed arrangement of fibers around the yam axis. Yam hairiness strongly depends on mean fiber position, with an inward shifting of the packing density leading to low yam hairiness.

This paper focuses on the dimensional, pilling, and abrasion properties of a series of plain jersey, lacoste, and two-thread fleece fabrics made from cotton ring and open-end spun yams as well as from blend yams (50/50 cotton/polyester, dyed). The results show that both structural differences and fiber type play a large part in determining the dimensions of these fabrics. It is apparent that the knits from blend yams have a lower dimensional stability when compared to fabrics from 100% cotton ring and open-end spun yams. Findings for the two-thread fleece fabrics suggest that the inlay yam mainly governs their dimensional behavior in the widthwise direction. The pilling tendency of the test samples and their resistance to abrasion are evaluated with the ICI pilling box (at three different test revolutions) and the Martindale abrasion tester, respectively. In addition, an extensive SEM examination is used to study the effect of fiber type and repeated launder ings on both pilling development and the degree of fiber damage within fuzz assemblies. The results show that unlike plain jersey fabrics, lacoste fabrics perform very well, and that in general fabrics knitted from open-end spun yams have a lower propensity to pilling. In the case of the two-thread fleece structure, the samples from 100% cotton (i.e., both face and fleece yam) open-end yams have higher pilling rates compared to FBOE (face yam is cotton, fleece yam is 50/50 PET/cotton) and FBB (both face and fleece yam are 50/50 PET/cotton) fabrics. The SEM study reveals that for the same number of test revolutions, the degree of damage to fibers within the fuzz entanglements tends to increase with an increased number of launderings, and that the kind of damage varies from small cracks and fractures to slight flaking, depending on the fabric and yam type. Note, however, that any damage occurring as a result of repeated launderings and pilling tests is not as severe as that reported in the literature. The lacoste fabrics have the least resistance to abrasion.

A new feature of flat textiles—impact permeability—is presented. It refers to differ ences in the behavior of textiles in stable and variable conditions of through airflows. A determination procedure is described in detail, and an example of an impact permeability assessment of a cotton fabric is presented.

The melezitose and trehalulose contents of a cotton sample heavily contaminated by whitefly honeydew are analyzed by high performance anion exchange chromatography (HPAEC) as a function of heating time at 200°C. Results indicate that the concentrations of melezitose and trehalulose on the surface of the cotton decrease exponentially as a result of thermochemical reactions. The mechanism and rate of each reaction is elucidated by similar heat treatment of pure melezitose and trehalulose with subsequent analysis of reaction products. The rate of thermochemical degradation in the case of trehalulose is of sufficient magnitude that its concentration on the cotton surface may be substantially decreased under controlled conditions of heat and time. The degradation rate of melezitose is nearly an order of magnitude smaller, and its concentration on the cotton surface is not substantially affected under similar conditions.

This work assesses actual increases in the cross-sectional areas of Classimat yarn faults with different spinning systems. The nature of diameter deviations of yarn faults with varying blends and yarn counts is investigated. The actual decrease in the cross-sectional area at the place of thin faults lies very close to the prescribed range of Classimat, but the actual increase in cross-sectional area of the thick faults is much higher than the Classimat range limit. Of the different materials, 100% viscose yarn thick faults show the highest percent deviation from the range limit compared to polyester-viscose, acrylic-viscose, and 100% acrylic yams for different counts and spinning systems. Thin faults, however, show no such trend with varying blends and different spinning systems.

A hollow spindle wrapped yarn is a new yarn consisting of a core yarn and a wrapping yarn. In order to improve the wrapped yarn' strength and evenness, it is twisted after the wrapping course in this research, thus forming a differential-twist wrapped yarn. The yarn has a particular differential-twist structure, caused by the different twists and twist directions between the wrapping yarn and the core yarn. The general equation of a twist's change in the twisting course is t' = t ± cos² β. This paper discusses two differential-twist wrapped yarns; one is the SWF (strand-wrapping filament) yarn, and the other is the Fws (filament-wrapping strand) yarn. With increased wrapping twists and twisting twists, the yam's tenacity increases, elongation rises, irregularity decreases, and abrasion resistance strengthens. The two yarns have different properties and structures, leading to different fabric styles.