bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Mechanical Model for Wool
Authors: Menefee Emory 
Published: March 2007

A model is presented which seems to account more fully for wool properties. This model contains two axially parallel parts: a microfibril made up largely of low-stability alpha-keratin and a matrix consisting of a series arrangement of high-stability alpha- keratin chains and amorphous protein partly extended in the axial direction. The matrix, which contains most of the cross links of the cortex, has a modulus considerably higher than that of the microfibrils. On extension, beta-keratin may originate from both the alpha chains and the amorphous chains. In solvents, the fiber is considered to have little tendency to swell longitudinally, because of restraints imposed by both amor phous and crystalline phases. Heretofore, it has been thought that the amorphous phase strives to swell isotropically but is restricted by the crystalline phase to swelling in the radial direction. Because of the high modulus now attributed to the matrix, the fiber structure appears to correspond mechanically to a honeycomb, at least with respect to tensile properties. I n compression, the microfibrils exhibit a high modulus, so that the composite structure also has some of the features of prestressed concrete. An example of the use of the model is given for the modulus of wool swollen in water and in water/formic acid mixtures.
Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA) Studies of Flame-Retardant Rayon Fibers
Authors: Godfrey Leonard E. A. 
Published: March 2007

The thermal behavior of flame-retardant fibers in which the flame-retardant chemical trapped inside the regenerated cellulose has now been studied, by differential thermal analysis (DTA) and thermogravimetric analysis (TGA). The thermograms obtained in a dynamic air atmosphere resemble those previously reported elsewhere for cellulosic materials treated with flame retardants in the conventional manner. In all cases, it has been found that the thermal degradation of the flame-retardant fibers begins at a lower temperature than for the control. A smaller quantity of flammable volatile matter is evolved and a much larger residue remains when the pyrolysis is complete. The total area of the exothermic peaks is, therefore, much smaller for the flame-retardant fibers than for the control. When the same flame-retardant fibers are heated in a nitrogen atmosphere, it can be easily seen that the onset of decomposition occurs quite suddenly at a definite temperature and clearly involves a reaction between the flame retardant and the cellulose. Examination of the flame-retardant chemicals themselves shows that these materials undergo a chemical change at approximately the same temperature, and it is this change that precipitates the interaction with the cellulose. Heating the flame-retardant rayon fibers in a conventional Fisher-Johns melting point apparatus shows that, although scorching occurs at lower temperatures than for untreated rayon, the difference is not large enough to have any effect on the processing or care of fabrics made from these fibers.
A Thermochemical Investigation of Cotton Flame Retardance
Authors: Smith James K. , Rawls H. Ralph , Felder M. Susan , Klein Elias 
Published: March 2007

Differential scanning calorimetry and thermogravimetric analysis curves were obtained for cotton cellulose in the presence of both flame-retarding and nonflame-retarding compounds and evaluated quantitatively for ΔH, activation energy, total weight loss, and char remaining after pyrolysis. Twenty-three compounds were tested and were found to fall roughly into three groups: (I) those which do not undergo decomposition in the temperature interval in which cellulose decomposes (200-400°C); (II) those which decompose appreciably during or preceding this temperature range; and (III) those which do not interact in any way with cellulose. It was found that, with increasing molar add-on, heat liberated from cellulose decreased for group I, increased for group II, and was not a function of molar add-on for III. A study of the kinetics of decomposition for these systems indicates that, while the majority of reactions proceeded as a pseudo first-order process, there are several exceptions to the trend. As would be expected for a first-order process, activation energy was found to decrease with increasing flame retardancy. Further, it has been observed that the addition to cellulose of any of the compounds from the first two groups lowers the onset temperature of decomposition and the temperature at which the first major weight loss begins. This temperature decrease approaches some type of limiting value for all the compounds, and varies from compound to compound. In addition, a large increase in remaining char results from a very small add-on, and this, too, tends to approach a limiting value as add-on increases.
Salt-Bath Process for the Chemical Finishing of Cotton
Authors: Tanquary A.C. , Liggett R.W. 
Published: March 2007

Wet fixation of durable-press resins in cotton fabrics has been accomplished by immersing the cloth, padded with re actants and catalyst, in a hot, concentrated solution of sodium sulfate or other suitable salt for a time (30 sec or less). sufficient to effect fixation .The treated fabric is then washed free of the salt and the unreacted agent and dried or processed further as desired. Presumably, the salt solution provides a heat-transfer medium that maintains the fibers in a swollen condition during reaction, with minimal leaching of the reactants from the fibers. Properties of the cured fabrics are es sentially equivalent to those of fabrics wet-fixed by the Mylar-bag and steam techniques. A limited mill trial, in which a Williams unit was employed for the salt bath, presented no unusual problems and es, sentially confirmed the laboratory results on wet fixation.
Studies of Nonwovens
Authors: Hubbell D.O. , Whitwell J.C. 
Published: March 2007

The nature of bonds in staple nonwovens bonded with thermoplastic fibers is examined with optical and scanning elec tron microscopes. The adhesive joints in rayon-vinyon and polyester-polyester systems are of the improper type, i.e., failure occurs at the bond interface. A quantitative method of characterizing the level of bonding in lightly bonded nonwovens is presented, based on dis tributions of effective fiber length and orientation. The first two moments of the effective length distribution are linearly related to binder concentration and bonding temperature in lightly bonded webs. An empirical relationship between breaking strength and bonding variables is also presented.
A Double-Label Radioactive Tracer Analysis of the Retention of Selected Fats on Cotton and its Relation to Yellowing
Authors: Sontag M.Suzanne , Purchase Mary E. , Smith B.F. 
Published: March 2007

A double-label radioactive tracer analysis was developed to determine the comparative retention of representative sebum components on cotton fabric after repeated soiling and laundering and to determine whether the presence or absence of clay significantly affected the retention of the fats. Retention was related to chain length, polarity, unsatura tion, and presence of clay. The yellowness of cotton soiled with pairs of fats was measured in the presence and absence of clay. Clay contributed significantly to the yellow color. When fat alone was present, there was no significant increase in yellowing until after the fifth wash for oleic acid and triolein. An interaction between the fats and clay caused additional yellowing which was possibly due to greater uptake of clay by entrapment in a fatty matrix and/or to catalysis of oxidation reactions of unsaturated fats by metal ions present in kaolinite clay. '
The Dimensional Properties of Knitted Wool Fabrics
Authors: Knapton J.J.F. , Richards S. , Fong W. 
Published: March 2007

The first paper of this series proposed and defined a means of attaining the fully-relaxed state of plain-knit fabric. This paper establishes the validity of this definition, which is shown to essentially discriminate relaxation shrinkage, due only to loop relaxation, from felting fiber migration to a more compact state without loop distortion. This discrimination is achieved by analyzing dimensions of the fabrics through 10 wash and tumble-dry cycles. We find that area shrinkage from any stage in processing to the fully-relaxed state depends on loop length and yarn count and, to a lesser extent, on fiber quality and yarn twist. Analysis of the dimensional changes from the fully-relaxed state through multiple washing and tumble-drying cycles shows: (1) for yarns spun from WURLAN shrink resist-treated top, area shrinkage increases linearly with the number of wash and tumble-dry cycles, but nonlinearly for untreated yarns; (2) for untreated yarns, shrinkages in length, width, and area depend on fiber quality, yarn twist, and loop length, with complex interactions among these variables; (3) at a low treatment level, linear and area shrinkages depend to a smaller extent on all these variables; (4) at a high treatment level, the WURLAN treatment adequately restricts felting to within an acceptable 8% area shrinkage limit; in this case, changes in length, width, and area from the fully-relaxed state are independent of all fiber, yarn, and fabric variables studied. We also find that change in length and width from the dry-relaxed to the fully relaxed state depends greatly on loop length, to a minor extent on fiber quality and yarn twist, and not at all on treatment level. These changes were always isotropic, that is, dimensions always decreased during relaxation.
The Thermodynamics of Sorption of Three Direct-Dye Mixtures on Cellulose
Authors: Porter John J. , Perkins Warren S. , Limb Yum 
Published: March 2007

The equilibrium absorption of binary mixtures of Direct Red 2, Direct Blue 8, and Direct Yellow 12 by cellulose film has been studied, and a correlation between single and mixture dyeing is presented. In each case, the competition of the dyes for available surface area suppressed the sorption. In some cases, evidence was obtained of interaction of the dyes in solution. When this occurred, it was difficult to define quantitatively the com petition of the dyes for available surface area. All of the results correlated with the degree of interaction in solution, as measured by transmission studies made at 90°C. The data are interpreted in terms of a Langmuir equation which has been modified to take into consideration the compe tition of two dyes for available surface area.
An Improved Method for the Rapid Determination of the Residual Grease on Scoured Wool
Authors: Samson A. 
Published: March 2007

In an investigation of the W.I.R.A. rapid grease-extraction apparatus, it was found that up to 20% of the methylene chloride extract of scoured wool could evaporate away at the heater mantle. This loss and others contributed to the low, and erratic results usually obtained when using the W.I.R.A. apparatus with scoured wool. An improved instrument (R5) has been devised with features which reduce or eliminate the main faults of the W.I.R.A. apparatus. The experimental investigations consisted of the extraction (with methylene chloride) of residual wool grease from scoured wool. Using four types of wool having residual wool-grease contents in the range 0.3-7%, the percent extrac tion from the Soxhlet, R5, and W.I.R.A. instruments have been compared. Highly significant linear relationships were found between the extract amounts from the R5 and Soxhlet apparatuses. The R5 instrument is sufficiently sensitive to distinguish between small discrepancies in residual wool grease found on different sections of a tuft of scoured wool.
Influence of Fiber Geometry on the Mechanical Properties of Assemblies During Processing
Authors: Scardino Francis L. , Goswami Bhuvenesh C. , Lyons W. James 
Published: March 2007

Sixteen samples of polyester-rayon blends, as well as a 100% rayon, and eight 100% polyester samples have been processed on the worsted system from raw stock through the 3rd pin-drafting stage. The blends in which 3-in. (nominal) staple was used were 65% polyester and 35% viscose rayon. The polyester samples provided all combinations of the following fiber variables, each represented by two contrasting levels: (a) surface roughness, (b) cross-sectional shape, (c) linear density, and (d) crimp. A single rayon sample of 3-den, bright, crimped staple was used in the blends. The total of 25 sliver samples from the card and first and third pin-drafting stages were evaluated for static-cohesion properties, as represented by maximum cohesive tenacity, textile modulus, and extension to maximum force. It was found that, generally, in blended slivers from all three stages of processing, fiber crimp in the polyester component had a statistically very significant effect on the three parameters measured. The rayon in the blends seemed to have little or no effect on the values of the parameters, as judged by comparison of these with corresponding values for the 100% polyester slivers. Measurements on the slivers showed slightly better evenness in the blended slivers containing the crimped polyester fibers than in those containing the samples without crimp. Blending of the rayon with the polyester samples was found to produce no significant differences in evenness.
Variation of Woven Fabric Length and Thickness with Regain
Authors: Stuart I.M. 
Published: March 2007

A theory of the hygral expansion of simple woven fabrics is proposed, based on Olofsson's theory of woven fabric struc ture. Hygral expansion is seen as the result of the competing effects of yarn swelling, yarn compression, and yarn curvi linear length extension with regain. Early attempts by the author to reconcile theoretical predictions with experimental data showed that it was necessary to suppose a yarn curvilinear-length expansion with regain in excess of that expected from the straightforward contribution from the fiber longitudinal expansion with regain. Taking into account measured yarn curvilinear expansion, which was found to be of the order of 3-4% dry-to-wet, a fair qualitative agreement of theory and experiment is obtained for unset fabrics. There is disagreement in the case of set fabrics below normal regain, which could be attributed to separation of the cross yarns. The fabrics are set wet and, as the yarns dry out and are affected by hygral "contraction," they could separate.
The Tensile Behavior of Woven Fabrics at Low and High Strain Rates
Authors: Skelton J. , Freeston W.D. 
Published: March 2007

Measurements of the breaking load of woven nylon and Dacron tapes at low and high strain rates showed that the tape strength is reduced at high pick densities and at a particular low pick density; the former was shown to be related to the high level of frictional restraints in the closely woven fabrics, while the latter is associated with the unique geometrical con figuration of the yarn filaments in the particular structure. The effect of various finishing treatments on the strength and the efficiency of translation of yarn strength to fabric strength was studied. The strength of the tapes is greater at high strain rates than at low strain rates for both materials. It was shown that the tapes are very efficient structures (>90%) under all test conditions. For medium pick densities. the efficiency approaches 100% and, under these circumstances, the effect of finishing treatments is minimized. In general, however, the loomstate tapes are strongest, with scouring causing a slight loss in strength, which is almost com pletely restored on treatment with silicone finish. Particular care is needed to carry out tensile tests on tapes at high strain rates, and a method was evolved for testing deliberately weakened specimens in order to avoid jaw breaks. In addition, a new variable radius-of-curvature capstan jaw was developed, which permits the attachment of tapes to other members such that the full potential strength of the tape is realized. It is suggested that a practical routine fastening system could be developed on the basis of the jaw design.
Oily Soil Retention by Abraded Durable Press Fabrics
Authors: Huisman Mary Ann , Morris Mary Ann 
Published: March 2007

A study was made of the effect of abrasion on the retention of oily soil by cotton and polyester/cotton durable press fabrics. One set of samples was abraded in the Accelerotor, and the other set was abraded by laundering. The abraded fabrics were then soiled with a radioactive labeled oily soil and laundered for a total of ten treatments. Samples abraded in the Accelerotor to a weight loss of approximately 20% had soil retention properties significantly different from the controls or samples that had received milder abrasive treatments. The severely abraded cotton samples showed a decrease, while the blend samples showed an increase in the amount of the 3H fraction of the soil retained.
Some. Structural and Physical Properties of Yarn Made on the Integrated Composite Spinning System
Authors: Nichols L.D. , Mohamed M.H. , Rochow T.G. 
Published: March 2007

One of the recent systems of yarn production is the Bobtex Integrated Composite Spinning (ICS). The process which produces a composite yarn that utilizes a polymer substrate with a fibrous surface. The production of this system ranges between 165 and 330 yd/min. The yarn used in this investigation was a two-component yarn, one of the early structures developed, which was found to have some favorable characteristics as well as some drawbacks. Work is going on to extend the study to the newer developments which have led to the production of three-component yarns. This paper presents a microscopical study of the yarn cross section which reveals the mechanism of binding the outer fibers to the polymer matrix. A small sample of woven fabric was microscopically analyzed and a cross section of the fabric is shown. Also, some of the physical properties were determined and the results are discussed.
Laundering Conditions for Improved Wash-and-Wear Appearance
Authors: Hjalmarsson Helge A. , Åsnes Harald 
Published: March 2007

A method for creasing and measurement of crease recovery angles in water has been developed. Creasing and crease recovery of fabrics of polyester, cotton, blends of polyester/cotton, acrylic, and nylon have been studied under conditions similar to those present in the washing process. The following parameters which influence wash wrinkling have been investigated: degree of swelling at the time of creasing, temperatures and times during creasing and crease recovery. The effects of these factors vary widely with the type of fiber material. The degree of swelling at the time of creasing affects the crease recovery angles of cotton. The temperature level and the duration of creasing and crease recovery are of great importance for polyester and acrylic materials.
The Absorption of Liquids by Compressed Fiber Systems
Authors: Steiger Fred H. , Kapur Chandra 
Published: March 2007

For maximum liquid-holding capacity, an uncompressed fibrous assembly requires wettable fibers of high wet modulus. Tests with rayons of various denier, state of finishing, and modulus indicate that, for compressed absorbents, it also is desirable to minimize the required compaction forces by reducing the dry modulus and resilience of the fibers. The use of wet crosslinked rayon, which has the requisite combination of wet and dry properties, leads to significant improve ments in absorbency. The effect of increasing bulk density on the liquid capacity per unit weight and capacity per unit volume of absorbents is discussed, and a mechanistic description of the latter is presented.
Effects of Blends of Medium-Staple Low and High Micronaire Reading Cottons, Sliver Weight, and Carding Rate on Card Loading, Sliver Quality, and Processing Performance
Authors: Simpson Jack , Fiori Louis A. , Castillon Audrey V. , Little Herschel W. 
Published: March 2007

This study determines the effect of such carding parameters as sliver weight, doffer speed, and carding rate on cylinder loading, card sliver quality, and waste removal on the processing performance of three blends composed of various per centages of low, average, and high micronaire reading cottons, blended to obtain a constant average micronaire reading of the mix. Blend composition, sliver weight, and carding rate had no significant effect on yarn skein strength, uniformity, and elongation. High carding rates decreased long-term card-sliver variability and increased card sliver short-term varia bility; increased yarn imperfections appreciably and decreased yarn grade slightly. At high carding rates, a blend con taining 30% of low and 70% of high micronaire reading cottons resulted in a greater cylinder load and lower fiber transfer than the other two blends containing various percentages of average micronaire reading cotton. This blend also had higher fiber breakage at high carding rates and slightly higher end breakages in spinning. Compared with light-weight card sliver, heavy card sliver increased cylinder load, majority hooks, yarn irregularity, and imperfections and decreased the cleaning efficiency of the card. More fibers and less actual waste were removed than when producing a light-weight card sliver.
The Pyrolysis of Cellulose at Rates Approaching Those in Burning
Authors: McCarter R.J. 
Published: March 2007

The thermal decomposition of cellulose was studied by a new thermal method suited to the measurement of faster reaction rates and to the problem of detecting concurrent reactions. The pyrolysis data for four types of relatively pure cellulose indicated successive supramolecular and molecular decom position steps, either of which may control the decomposition rate contingent upon the temperature history. The molecular decomposition step is interpreted as a first-order depolymerlzation reaction with an activation energy of 401/2 kcal/gmol. The data for cellulose treated with retardant (1.5 wt% KHCO2) indicated two principal decomposition reactions. An initial lower-temperature reaction evolved principally H2O and CO2 from well-dried samples. The following main decomposition reaction exhibited the same kinetic parameters as the counterpart depotymerization step of the untreated cellulose, but evolved different vapor products. Tests and analyses of these celluloses at transitional stages of decomposition are summarized. The implications of the data concerning the mechanism by which the retardant functions are discussed.