bluuebunny/crossref_metadata_2025 huggingface dataset:
Solubility as a Criterion of Cross-Linking in Wool
Authors: Caldwell J.B. , Leach S.J. , Milligan Brian
Published: March 2007

Three commonly used solubility tests have been applied to wools treated with various mono- and bifunctional active esters. Treatment with the bifunctional esters invariably leads to large reductions in solubility. Those monofunctional esters which introduce bulky groups into wool also decrease its solubility. However, bifunctional reagents reduce the solubility to a greater extent than monofunctional reagents of similar size, particularly with the performic acid-ammonia and urea-thioglycollate tests. The urea- bisulfite test, on the other hand, is so sensitive in detecting chemical modification that it differentiates poorly between the introduction of bulky groups and cross links. Whereas none of these tests can be used to prove the presence of cross links unequivocally, the former two can be used, in conjunction with other tests, as a qualitative criterion of cross-linking.
Wet-Fixation Process for Improved Durable-Press Cotton1
Authors: Hollies Norman R. S. , Getchell Nelson F.
Published: March 2007

This paper is concerned with a new research development for imparting durable press to cotton in which finishing resins are deposited inside the wet, swollen cotton fiber. This is accomplished by padding an N-methylol resin-mineral acid solution on the fabric, heating the fabric in a closed or semi-closed container for 15 min at 180° F, neutralizing in sodium carbonate solution, washing, and drying. The heating results in deposition of the resin in the fiber in such a manner that it is not removed by washing and so sustains the fibers in a somewhat swollen condition. Subsequent application of cross-linking catalyst followed by a high-temperature dry cure results in only modest loss of fabric strength compared with conventional pad-dry-cure processing. The key to arriving at good strength properties of the finished fabric and high levels of fabric performance, both in resistance to wrinkling and good crease retention, lies in the use of two resin components. One of these, called a polymer builder, acts to swell the fibers and keep them in a swollen state (melamines are particularly effective in this regard) ; the second component is primarily a cross-linking agent for cotton, contributing only moderately to the swelling of the fiber but enhancing wet wrinkle recovery and, once catalyzed and dried, imparting high dry wrinkle recovery to the fabric (dihydroxy dimethylolethylene urea and methylol carbamates are good examples of this class). A total dry resin add-on of 8% to 15% is required to achieve the enhancement of fabric properties. Resin combinations for use on colored goods and white fabrics have been developed.

A twill fabric treated by this process in the laboratory gave breaking strength retention values of 60% (filling), dry wrinkle recovery values of 300 degrees, and wash- wear ratings of 5. This fabric, converted to simulated trouser cuffs, showed less wear in laundering than cuffs conventionally finished by pad-dry-cure at comparable perform ance levels. In 20 laundering and tumble-drying cycles, most of the wet-fixed samples were not worn, whereas the pad-dry-cure controls all failed, on the average, at the sixth cycle. Similar results have been obtained in other abrasion tests.
Carbamate-Catalyst Systems for Low-Temperature, Rapid Curing of Alkyl and Alkoxyalkyl Carbamate Finishing Agents1
Authors: Goodman H.G. , Lourigan G.H. , Dupraz C.A.
Published: March 2007

The greater lubricity of the alkyl ethers of alkylene glycols, in comparison to that of their corresponding alkanol analogs, suggested that the lubricating properties of the glycol ethers might be transmitted to their respective carbamic acid esters and, in turn, through suitable methylol derivatives, to fabric treated therewith. Increased inter- , molecular lubricity within the finished fabric might lead to improved tear strength, abrasion resistance, and fabric hand. To this end, a new class of carbamates, the alkoxyalkyl carbamates, based on polyalkylene glycols and certain of their alkyl ethers, have been investigated as finishing agents for cellulose. The relation of the chemical structure of the carbamate to the properties of fabric finished with the methylolated carbamate is discussed. Data are presented to illustrate the suitability of methylolated methoxyethyl carbamate as a cellulose reactant.

In addition, the techniques employed in preparing carbamate finishes have been studied and the influence of methylolation conditions, such as formaldehyde/carbamate molar ratio; initial methylolation pH, and reaction temperature on both finish composition and performance properties is examined.

An attempt to reduce or eliminate certain difficulties encountered in large-scale carbamate finishing led to the development of a new carbamate-catalyst system. This unusually efficient carbamate-catalyst system is discussed in detail and its low-tempera ture, rapid-cure characteristics are demonstrated.
Dye Structure Relationships for Dyeing Metal- Containing Polypropylene
Authors: Turbak A.F.
Published: March 2007

Dyes containing the imino-azo structure C—N=N— are valuable for dyeing poly olefins which contain transition-metal additives. The transition metal forms strong complexes with the imino nitrogen and with the azo nitrogen atoms. In those cases where the dyed fibers are not fast to drycleaning, these complexes are strong enough to cause removal of the transition metal into the drycleaning medium. Thiazole-azo structures prepared from fused ring or polar substituted thiazoles exhibit good dry cleaning fastness.
Sonic and Ultrasonic Irradiation of Cotton Fibers
Authors: Boucher R.M.G. , Staples M.L.
Published: March 2007

An investigation was made of the effect to exposure of high-intensity airborne acoustic waves on the physical and chemical properties of Deltapine and Acala 4-42 cotton. From the results of our experiments it appears that, with the exception of small changes in tensile strength, the fibers of both varieties of cotton do not seem significantly modified until one reaches the threshold of cellulose combustion. It has also been clearly estab lished that the most important factors which control sound to heat degradation in cotton fibers mass are the apparent density of the fibers bundle and the amount of acoustic energy radiated per gram of sample. It has also been shown that at equal intensity levels the sound degradation mechanisms seem to be frequency dependent and exhibit a maximum in the 22 kcps region. The peak sound intensity at any point of an irradiated fibers bundle determines the flash point of cellulose combustion.

Regarding sound degradation rate and combustion threshold, no significant difference was noted between the Deltapine cotton grown under conditions of natural rainfall and the Acala 4-42 grown under irrigated conditions. It has also been confirmed that due to rapid sound degradation and damping phenomena high intensity airborne acoustic waves are of very little help to separate trash from cotton fiber masses.
The Tumble-Drying Process and Acrylic Knitted Fabrics1
Authors: Hurley R.B.
Published: March 2007

The tumble-drying process is discussed relative to its effect on the dimensional stability of acrylic knitted fabrics. Area shrinkage of these fabrics increases with increase in tumble-dryer temperature. Cycling of the temperature during drying is shown to contribute significantly to variability in fabric shrinkage.

Fabric compaction or compression during tumble drying is shown to promote longi tudinal or along-wale loop slippage, if the stitch length is sufficiently large so as to allow free distance between loop apices in adjacent rows of needle and sinker loops. Loop slippage is shown to occur without appreciable relaxation shrinkage under certain conditions during tumble drying after dry cleaning. The mechanism of compressional shrinkage is proposed as an explanation of some anomalies involving tumble drying reported in the literature.
Weaving Processes-Effects of Non-Preemptive Priority and Operator Interference on Output
Authors: Hines William W. , Nass Alan W. , Flege Raymond K.
Published: March 2007

Warp yarns are depleted in the weaving process and must be replaced. Principles of queueing theory are applied to warp beam replacement.

Looms may be serviced with new warp beams on a first-come-first-served or on a priority basis. Comparative studies have been made to determine the queueing dis cipline that would maximize loom output or loom operating efficiency for the same number of repairmen.

Monte Carlo methods have been used for examining the queueing process. The actual universe of looms was replaced by a mathematical model that was demonstrated to be theoretically equivalent to the actual universe.

For the particular system investigated, the priority queue discipline proved to be marginally more economical than the first-come-first-served discipline.

The effectiveness of simulation as a tool for this type of study has been demonstrated.
Grafting of Preformed Polystyrene onto Cotton Cellulose
Authors: Avny Yair , Schwenker Robert F.
Published: March 2007

Grafting of preformed polystyrene onto cotton cellulose has been investigated. Low molecular-weight, carboxyl-terminated polystyrene was synthesized by anionic poly merization techniques and polymers with DPn ranging between 9 and 120 were obtained. Grafting was achieved by reaction of the acyl chloride derivatives of the carboxyl- terminated polystyrene with cotton yarns and fabrics. Graft copolymers with low molecular-weight side chains and relatively high degrees of suiostitution were obtained. The grafting degree of substitution was mainly dependent on the molecular size of the reacting preformed polymer, whereby high molecular-weight preformed polymers lead to low degrees of substitution. Wrinkle recovery and water of imbibition of the modified fabrics and yarns were determined.
Lightfastness of Dyes on Wash-Wear Cotton
Authors: Frick J.G. , Kullman Russell M. H. , Reinhardt Robert M. , Reid J. David
Published: March 2007

A study of the accelerated lightfading of dyes caused by wash-wear agents on cotton fabric showed that substituent groups on the agent could change the effect unpredictably. Hydroxyl substituents, however, always gave a slower rate of fading. A previous mechanistic theory for the phenomenon is incomplete, since at least two separate actions occur. One requires the presence of residues from the agent at the time of exposure to light so that they may participate in the photochemical reaction. The other is a sensitization of the dye by the agent during treatment and does not require the presence of agent at the time of exposure.
Basic Mechanics of Fiber Reinforced Composite Materials
Authors: Whitney J.M.
Published: March 2007

This paper is an introduction to the basic mechanics of fiber reinforced composite materials. Emphasis is placed on describing the general approach to composite prob lems and how principles of mechanics can be utilized in predicting composite mechanical behavior. Some description of composite materials and their fabrication is also in cluded. Because of the anisotropic and non-homogeneous character of these materials, basic principles of anisotropic mechanics and application of these principles to composite materials are discussed.
Kinetic Examination of the Pyrolysis of Tritylated Celluloses
Authors: Conrad Carl M. , Harbrink Pieter
Published: March 2007

The Chatterjee method for reaction kinetics by thermogravimetry was applied to two control cellulose samples and to five of their triphenylmethyl ether derivatives, varying in degree of substitution from 0.31 to 0.79 per anhydroglucose unit. The same samples were also examined by the Anderson and Freeman method and by an empirical trial of certain probable orders of reaction in conjunction with the generalized kinetic- reaction formula and the Arrhenius equation. The three methods of treating the data from the thermograms were mutually advantageous from the computational standpoint, requiring relatively small additional mathematical effort in proceeding from one to the other. All methods indicated zero- or low-order reaction at the beginning of pyrolysis (ca. 240°C), followed by first or higher order beginning at about 270°C. The tar phase of the reaction was completed at about 350°C. Usually, only one extended region of first-order decomposition was detected in the control celluloses, but two or more, with di erent Arrhenius parameters, were detected in the ether drivatives. One of the first-order regions, usually the intermediate on with very low activation energy, was associated with scission of the trityl group (285-310°C). In certain cases, the char region (350-500°C) was examined by the same techniques but without discovery of a recognizable kinetic law. 'The results are in substantial agreement with the chain mechanism of cellulose pyrolysis proposed by Chatterjee and Conrad.
Thermoanalytical Studies on the Durable-Press Curing of Cellulose
Authors: Miller Bernard
Published: March 2007

In the course of a series of thermoanalytical investigations on durable-press curing processes for cotton, attention has been focused on the acid salt catalysts. Studies on the sequence and nature of the chemical events occurring during heating through the tem perature range of a typical durable-press cure have been carried out by using differential thermal analysis ( DTA ) and thermogravimetric analysis (TGA). Different methods of combining cotton and salt were compared. In one sequence, cotton was soaked with aqueous salt solutions; in another, the two solids were separated from each' other by a porous barrier. In a few instances, an aminoplast cross-linking resin was included in the reaction system.

Among the detectable processes, when nitrate salts were used, was a strongly exo thermic reaction accompanied by a rapid weight loss, not characteristic of any one of the substances in the mixtures. This decomposition could be modulated with respect to temperature, rate, and extent, depending on the concentration, environment, and geo metric arrangement of the system. In an attempt to explain these effects additional studies on zinc nitrate were carried out showing that its thermal behavior was not what might be implied from values stated in the cited literature. On the basis of the accumu lated data, it is suggested that the exothermic decomposition is the consequence of the oxidative attack of NO2 on cellulose, the former being produced by the thermal breakdown of the nitrate salt.
Improved Durable-Press Cottons Produced by Conventional Pad-Dry-Cure Procedures Using Pairs of Monofunctional and Difunctional Swelling Reactants 1
Authors: Gagliardi D.D. , Wehner A. , Cicione R.J.
Published: March 2007

Results are reported of attempts to develop a single-bath treating mixture containing a pair of monofunctional and a difunctional cellulose swelling reactants. A variety of monofunctional cellulose swelling reactants were prepared and tested with several cellu lose cross-linking agents. Some of the monofunctional reagents showed only minor improvements in fabric strength properties. Others, with selected cross-linking agents, showed substantial improvement. With selected monoheterocyclic ureas, N-methylol acetamide produced durable-press 100% cotton with higher tensile, toughness, and abrasion resistance than the control treatments. These results have been confirmed by cuff laundering tests. An analysis is presented of the interactions of the different pairs of reactants and the mechanism of improved properties produced thereby.

The degree of overall strength improvement found with selected pairs varies with the concentration of each reagent. , Highest improvements are produced at high total solids concentrations where cotton swelling by the reagents, is very high. These high concentrations, however, may be economically impractical. At total solids level of 15-25%, a major improvement in all cotton fabric properties, is produced. At the present time, it is not known whether each reagent reacts independently with cellulose or whether some interaction between the two swelling reactants takes place during curing. Current emphasis is directed to the synthesis of optimum pairs of reagents, although useful candidates have already been developed for practical use in precure or delayed-cure systems. The advantage of the present process is that it can be done under conventional finishing-plant treating conditions.
Studies on Hook Formation and Cylinder Loading on the Cotton Card
Authors: Ghosh G.C. , Bhaduri S.N.
Published: March 2007

The effect of various carding parameters on hooking and loading characteristics and on yarn quality has been investigated for a California 15/32 -in. cotton.

Lickerin speeds and method of doffing the card web were shown to have no effect on the pattern of hook formation which is influenced mainly by cylinder and doffer speeds and the hank of the delivered sliver. These same factors also influence the loading on the cylinder and the coefhcient of transfer of fibers to the doffer. No clear-cut relationship between loading and hooking has, however, emerged. Increased doffer and cylinder speeds, at a constant carding rate, were seen to decrease yarn imperfections.
A Probability Model for Random Fiber Breakages
Authors: Lee Sung Won
Published: March 2007

Applications of the probability model for random fiber breakage which was derived in Part I are demonstrated. The parameters of the model for an arbitrary initial fiber- length distribution are estimated by the nonlinear least-squares iterative method. Some practical uses of the estimates of parameters are shown. Different modes of fiber break age for two different lots of cotton due to opening-carding process are assessed in terms of average number of break points and probability of fiber breakage, thus, providing complete clarification to the fundamental questions raised at the beginning of the study and a realistic interpretation to the random fiber breakage phenomena.

Results of the application show that the probability of fiber breakage on fiber length is moderately nonlinear and sizable three segments fiber breakage was seen to be present, especially for long fiber groups, although in an over-all sense it was fairly small. Fiber breakages into more than four segments were negligible. These will, of course, depend on the particular breakage process under study. It is demonstrated that the model can be used to assess analytically whatever the mode of ordinary random fiber breakages, allowing more flexible relation between breakage probability and fiber length and taking multi-segments fiber breakage into account.
Mathematical Models and Measurement of Fiber Hooks
Authors: Pittman Robert A. , Tallant John D.
Published: March 2007

A general equation is offered for the variation of number and weight length distribu tions of the lengths of fibers as measured in projection along some fiber structure. Two models are examined and one model, "the ideal random hook," is used to derive ex pressions for the "equivalent random hooks per fiber." Experimental techniques for determining the parameters necessary to measure hooks by the method are discussed. Expressions for the excess number of hooks on one end of the fibers over the other end are derived and the experimental technique for their evaluation is analyzed. The basic technique suggested in an earlier paper for the measurement of weight mean lengths is shown to be valid for variations in weight fineness.
Sewing Needle Temperature
Authors: Howard G. Michael , Parsons David
Published: March 2007

The general problem of sewing-needle temperature rise due to frictional heat genera tion is discussed. Several possible mathematical models which could be used to predict needle temperatures are considered. The solution of even the simplest model which seems capable of giving accurate results would require extensive use of a high-speed digital computer. Because the parameters which govern the frictional heat generation and convective heat-loss mechanisms cannot be predicted with any accuracy, the probable computer results do not seem worth the effort required to obtain them. A very simple calculation of heat losses indicates that the thermal conductivity of the needle is the most important property governing needle heat dissipation.

An experimental method of determining the needle temperature by infrared flux measurements is described. The many variables, such as emissivity, geometrical view factors, and signal shape and frequency which relate the flux to the needle tempera ture, are discussed. A calibration procedure is described which eliminates these factors as variables and permits determination of the peak needle temperature with an accuracy of ±2°C.
Oxidative Degradation of Nylon 66 Filaments
Authors: Vachon Raymond N. , Rebenfeld Ludwig , Taylor Hugh S.
Published: March 2007

Drawn and undrawn nylon 66 filaments were exposed to oxygenated aqueous systems, and the extent of chemical degradation was studied as a function of time. Degradation was estimated by measuring the changes in both chemical and physical properties. At the same time, oxygen absorption measurements were made and these were correlated with the observed structural changes. A significant pH effect on the rate and extent of the degradation was found. Viscosity measurements in m-cresol and other physical and chemical properties show that there is little degradation at pH 3 and that the rate of degradation increases with pH until a maximum is reached at pH 8.3, after which the rate again decreases. A tentative mechanism for the autoxidation of nylon, including pH dependence, is postulated.
Studies in Wool Yellowing
Authors: Lennox F.G. , King M.G.
Published: March 2007

Changes in the yellowness of wool during exposure to sunlight or to an artificial source resembling sunlight (the Xenotest) depend not only on the relative proportions of blue light and uv radiation, which cause partial bleaching and yellowing, respectively, but also on the exposure period and on the initial natural yellowness of the sample. The bleaching reaction is rapid and short-lived and is most pronounced with deeply yellow wools, whereas uv yellowing is more apparent with paler specimens and is sustained throughout irradiation. Even with the deeply yellow samples, the uv yellow ing reaction eventually supervenes and proceeds at a similar rate for all wools, although the level of yellowness at any particular stage of irradiation varies from one wool to another. A linear relationship exists between the initial natural yellowness of scoured wool and the change in yellowness during Xenotest irradiation for any particular period.

Action spectra for changes in shade of naturally yellow wool and of wool after yellow ing in the laboratory by either uv radiation, dry heat, or hot alkaline buffer are similar. yellowness increasing to a maximum with decrease in wavelength down to 300-320 mμ (the lowest waveband examined) and decreasing to a minimum at 440-460 mμ in the blue region. However, the absorption spectra determined by the o-dichlorobenzene immersion method differ and so, in general, do the changes in yellowness during irradiation in the Xenotest.

Natural yellowness is more likely to be attributable to the deposition of a thin pigment layer at the surface of the wool fiber than to the effects of uv radiation, heat, or alkaline conditions while on the sheep. This important difference in the distribution of pigment between natural and artificially yellowed wools may suggest new methods of improving the color of wool.
Swelling Degree of Cellulose Materials and Hydrolysis Rate with Cellulase
Authors: Ogiwara Yoshitaka , Arai Kenichiro
Published: March 2007

We investigated some relationships between the hydrolysis rate with cellulase and the swelling degree of the cellulose fibers of different samples. The water retention value (WRV) determined by the centrifugal method was used as a measure of the swelling degree. A linear relationship was observed between the hydrolysis rate and the WRV of the untreated pulps of different chemical composition and crystallinity. A similar linearity was observed also for pulps treated mechanically or chemically, but the slope of the regression line differed with the treating methods, and it decreased in proportion with the degree of degradation of the fiber structure.
Observations Concerning the Carbonization of Viscose Rayon Yarn
Authors: Ross Stanley E.
Published: March 2007

The course of carbonization of continuous filament viscose rayon yarn was followed, using various experimental techniques. The disappearance of the cellulose hydroxyl function in the early stages of carbonization was determined by chemical means, and the factors of weight loss, shrinkage, carbon level, and resistivity were also determined. In addition, observations of selected samples using DTA and scanning electron micros copy techniques were also carried out.

The experimental data indicate that the reaction which occurs at 230-260°C involving a major loss in weight of the viscose is preceded by a cross-linking reaction involving the cellulosic hydroxyl groups. As the treatment temperature is increased, the yarn undergoes various other changes in properties, including a sharp reduction in resistivity beginning at a temperature of approximately 500°C. After exposure at approximately 1400°C, the carbon content of the yarn increases to a level of approximately 95%. Examination of the surface of carbon fibers with the scanning electron microscope shows a relatively unmarked surface bearing similar striations to the viscose precursor.
The Dynamics of Weft-Knitting Further Theoretical and Mechanical Analyses 1
Authors: Knapton James J. F.
Published: March 2007

A computerized analytical technique for studying a mechanistic model of weft-knitted loop formation is described. This technique overcomes a previous deficiency of the model by allowing for the individual knitting tensions to be evaluated for any given set of knitting conditions. Consequently, each yarn and machine variable may now be studied independently, to investigate their individual effect on yarn knitting perform ance, machine efficiency, and quality of finished fabric.

The results of studies on 18- and 36-gage linear cam systems show that the major vari ables are yarn friction and cam angle. Changes in input tension have only a second- order effect on yarn knitting performance. Great knitting advantages are hypothesized by the use of 60° linear cam systems over the conventional 45° designs for 18-gage equip ment, but little advantage is noted on 36-gage equipment for the same cam angle change. However, this work does suggest that present designs of 36-gage machines are inade quate, and new needle design features are sugested which are likely to radically improve the mechanical performance of this type of machinery.
The Behavior of Fabrics in Shear
Authors: Spivak S.M. , Treloar L.R.G.
Published: March 2007

An analysis has been made of the geometrically similar tests of bias extension and sim ple shear for plain-woven fabrics. This analysis makes possible calculation of the values of the equivalent shear strain and equivalent shear stress, corresponding to measured values of tensile strain and tensile stress in bias extension. Comparison of values thus derived with direct measurements in simple shear shows deviations of varying amounts, depending on the type of fabric examined. It is concluded that it is not possible simply and directly to predict the complete stress-strain properties of a fabric in simple shear from measurements of bias extension.
Studies on Cellulolytic Micro-Organisms
Authors: Betrabet S.M. , Dasani Usha P. , Bhatt Indira G.
Published: March 2007

Microbial degradation of cotton indigenous to the Bombay region of India was investi gated, with particular emphasis on cellulolytic nonfungal micro-organisms.

About 76 bacteria, 49 actinomycetes, and 38 fungi were isolated by the enrichment culture technique from a arge number of cotton and fabric samples suspected of micro biological damage. Well known cellulolytic fungi belonging to genera Myrothecium, Chaetomium, Trichoderma, Memnoniella, etc and myxobacteria were conspicuously absent, whereas Streptomyces sp., which were encountered in fairly large numbers, seem to have an important role in the degradation of cotton along with Aspergilli.

Bacteria, though incriminated in a large number, were mostly feeble in cellulolytic activity with the exception of isolates like Cellvibrio and Nocardia. Of particular interest was the large number of highly cellulolytie Streptomyces. This group has been isolated in a large number for the first time from cotton and fabric, though they have been known as cellulose digesters for a long time. Fungi, too, as expected, were highly cellulolytic. Aspergilli were most dominant. Penicillia and certain other fungi, even though not highly cellulolytic, were found in large numbers and were responsible for bad appearance, musty odor, and stains on cotton and fabric.

The ecological pattern emerging from this study shows that cellulolysis in nature is a synergetic process, where fungi and streptomyces play a major role in bringing about degradation of cellulose, while bacteria, with few exceptions, seem to help mainly in the further decomposition of degraded cellulose. Bacteria, perhaps, may be devastating under very high humidity, bordering on wet conditions.

Nutritional requirements of 15 cellulolytic isolates, mostly streptomyces, were also studied.
Principles of Reactivity of Nitrogenous Agents with Cotton
Authors: Vail Sidney L. , Kullman Russell M.H. , Reeves Wilson A. , Barker Robert H.
Published: March 2007

A new approach to circumvent the direct relationship between the reactivity of N-methylol agents and hydrolysis rates of the cellulose derivatives under acidic conditions has been studied. To achieve a more durable product from a reactive agent with cellulose, an irreversible system was sought through incorporation of a suitable leaving group, such as acetoxy, to activate the agent. Reactivities of acetoxymethyl, hydroxymethyl, and methoxymethyl derivatives of N-methyl-2- imidazolidinone (MI), methyl carbamate (MC), and benzamide (B) have been compared under selected, acidic conditions. Reactivity contributed by carbonium-immonium ion stability is in the expected order (parent amide given) MI>>MC>B. Reactivity is significantly altered by the leaving group and is in the order acetoxy >> hydroxy >> methoxy. Substrates for reactivity studies included isopropanol, water, and cotton. Acetic acid released by reaction with these substrates and an acetoxy derivative had only a minor catalytic effect upon the reaction rate except in the fabric treatments carried out in the presence of magnesium chloride. Acetoxy-derivatives of similar polyfunctional agents are similarly activated as long as the acetoxy groups are isolated from one another; however, vicinal diacetoxy glyoxal resins appear to be of the same general order of reactivity as the corresponding dihydroxy derivatives. Use of these active agents in nonaqueous solvent systems is suggested and limitations for use in aqueous systems are discussed.
The Effects of Tumble-Drying on Some Sensory and Physical Properties of Acrylic Knitwear
Authors: Brown Peter
Published: March 2007

Tumble-drying techniques similar to those which might be encountered in home laundering are investigated. The effects of fabric dimensions and aesthetic softness and limpness are studied, and a tentative explanation of the aesthetic changes in terms of observed physical differences is offered.
A Theoretical Analysis of the Plain-Knitted Structure
Authors: Shanahan W.J. , Postle R.
Published: March 2007

A theoretical analysis was made of the relaxed plain-knitted structure. The analysis differs from previous ones in that no arbitrary geometrical loop shape is assumed and no empirical methods are used. The loop configuration is de rived from consideration of the reaction forces and couples acting within the structure, their magnitude being determined by the yarn displacement necessary for loop interlocking. A minimum-energy structure is shown to exist; this structure is fairly independent of fabric tightness and yarn properties. The actual energy minimum is fairly shallow, so that in practice some difficulty could be expected in obtaining a perfectly relaxed fabric; this would lead to a corresponding spread in experimental values of plain-knitted fabric shape and dimensions. The numerical values of fabric dimensions obtained from the analysis show good agreement with the experimental data reported by other workers.
Fibers from Polyhexamethylene Terephthalamide
Authors: Quynn Richard G.
Published: March 2007

Polyhexamethylene terephthalamide (nylon 6-T), wet-spun from concentrated sulfuric acid, yields poorly or moderately oriented filaments, depending on the amount of stretch during spinning. Such fibers cannot properly be called amorphous, since they characteristically show a "line-lattice" or one-dimensional order along the chain direction. There appear to be several alternate ways in which the chains pack together laterally in the spun fibers, and hot-drawn fibers with full three- dimensional crystallinity exhibit polymorphism. The birefringence and certain features of the x-ray pattern correlate with tenacity in both spun and drawn fibers.
Use of Methods of Heterogeneous Chemical Kinetics and Nonequilibrium Thermodynamics for the Quantitative Evaluation of the Rate of Fixation of Reactive Dyes by Fibrous Materials 1
Authors: Krichevsk G.E. , Movshovich I.M.
Published: March 2007

Dyeing and printing of fibrous materials with reactive dyes are examined as a problem of heterogeneous chemical kinetics. The rate of this fixation process is affected by the rate of supply of dye molecules to the active centers of the fiber, by the sorption capacity of the fiber, and by the rate of the two competing reactions of the adsorbed dye with the fiber and of the dye in the solution with water (hydrolysis).

Each of the above enumerated stages of the fixation process is examined independently from a quantitative point of view, and the specificity of the mechanisms of these stages for reactive dyes is shown.

Methods of heterogeneous chemical kinetics are proposed and applied for the quantitative evaluation of the rate of fixation of reactive dyes by the fibers and materials. These have made it possible to derive and solve, for definite boundary conditions, the kinetic equations that describe the rate of fixation of active dyes by the cellulosic fiber.

It is shown that it is expedient to utilize simplified solutions of the kinetic equations for the fixation process in the kinetic and the diffusion regions.
Fatigue in Textile Fibers1
Authors: Lyons W. James
Published: March 2007

The practical advantages of a knowledge of the appropriate lifetime distribution in fatigue research are pointed out. The logarithmic lifetimes of two sets of polyester specimens, one fatigued over a 47-day period at a constant force amplitude (CFA) of 11.5 g, the other over a shorter period at a CFA of 13.4 g, were judged to conform better to the Weilbull third-asymptotic distribution than to the normal distribution, on the basis of visual inspection. A decline of about a decade and a half in the average logarithmic lifetime resulted from the higher level of loading.

Measurements of the deviations from visually fitted straight lines of observed logarithmic lifetimes of the polyester and a polyamide sample, plotted on Weibull and on normal probability coordinates, shows that the observed results conform better to the former distribution. This finding is confirmed when the analysis is applied to the deviations from a line located by the squares method.

A series of tests, employing the same polyester, was undertaken to assess the feasibility of attempting to load specimens with force-amplitudes of improved uniformity on a gram-per-denier basis. The technique adopted was to match care fully the slightly scattered linear densities of fiber specimens with the constants of the individual springs on the machine. While, in the final test, the spread in the loading (g/den) had been reduced to 5%, no clearly detectable improvement was found in the uniformity of logarithmic lifetimes—the ultimate objective. The conclusion is that structural dif ferences among specimens so far over-ride small nonuniformity in loading as to make it unprofitable to give time-con suming attention to the latter.

For fibers of the polyester sample fatigued at four successively increasing force-amplitudes, the lifetime data showed moderately good conformance to the cumultive-damage principle. Values of 0.79 and 0.75 for the sums of damage ratios were found, where simple theory calls, for unity; though a newer hypothesis predicts deviations.

A plot of the results of several tests on the polyester sample shows a general, substantial decline in logarithmic life times with increases in the force-amplitude.

The lifetimes of specimens of the aromatic polyamide sample were found to conform to a Weibull distribution and to have an average value and range comparing favorably with those of the polyester sample under relatively the same conditions.
Reactive Dyes for Wool
Authors: Seshadri S. , Mani K.V.S.
Published: March 2007

Several α-bromoanthraquinone derivatives and quinizarin-2-sulfonic acid have been found to react with the thiol (cysteine) parts of wool. The dyeing properties (extent of exhaustion and fixation) and the light fastness of the dyeings have been studied.
Effect of Ambient Atmospheric Conditions During Spinning on Yarn Properties and Spinning Efficiency
Authors: Pillay K.P.R.
Published: March 2007

Further studies on the effect of ambient atmospheric conditions during spinning on yarn properties are described in this paper. The results obtained indicate that maximum lea strength in the spinning room is obtained when yarns are spun at the highest level of relative humidity (76%) and lowest level of temperature (70°F); maximum strength under standard laboratory conditions is shown by yarns spun at the highest levels of relative humidity (76%) and temperature (91°F). Maximum yarn elongation under standard laboratory conditions is obtained with yarns spun at the lowest level of tem perature (70°F) and humidity (34%). Yarn properties are significantly influenced by spinning factors and absolute humidity of the spinning room, the extent of change being different for different types of cotton.
All-Cotton Durable-Press Fabrics of High Strength from Slack-Mercerized, Partially Restretched Yarn
Authors: Murphy A.L. , Margavio M.F. , Welch C.M.
Published: March 2007

The virtual elimination of break and tear strength losses in cotton sheeting during conventional pad-dry-cure treat ments with DMEU, formaldehyde, APO, and bis(2-hydroxyethyl) sulfone has been observed. At wrinkle recovery angles of 270-300° (W + F), the tearing and breaking strength retention, or the average of these, in yarn-mercerized fabric were often equal to the values for untreated unmercerized fabric. Yet the cross-linking of unmercerized fabric produced 33- 55% losses in breaking strength and 45-68% losses in tearing strength. Moreover the scoured fabrics, yarn-mercerized and unmercerized, were nearly identical in strength prior to cross-linking. The experimental fabrics, woven of yarn only partially restretched after slack-mercerization, possessed higher elongation when cross-linked than did unpretreated cross linked fabric.

Since strength losses during cross-linking can be varied or nearly eliminated without changing the wrinkle resistance ob tained, strength losses and wrinkle recovery are evidently produced by separate and, in some cases, independent cross-link mechanisms. Work of others indicates strength and elongation losses in conventional cross-linking processes are due to the spiral structure of fibrillar windings in the secondary wall of the cotton fiber. The fibrils cannot unwind fully and equally under stress after being cross-linked. Present findings suggest conditioned wrinkle recovery, as imparted here, arises in more elementary structural units, such as cross-linked microfibrils, where tensioning has little effect.

The possibility that a strength maximum can occur in cotton at optimal levels of cross-linking is re-examined, in view of evidence that swelling and tensioning pretreatments, as well as polymer inclusion during cross-linking, can alter the amount and type of cross-linking already present in cotton because of hydrogen-bonding and crystallinity.
Effect of Fiber Initial Modulus on its Migratory Behavior in Yarns
Authors: El-Behery Hassan M. , Batavia Dharmendra H.
Published: March 2007

The influence of fiber initial (tensile) modulus on the migratory behavior and physical properties, especially abrasion resistance, of polyester-cotton blends was studied. Nine selected polyesters were blended with combed cotton on the cotton system. For each type of polyester, the polyester/cotton ratio was nominally 50/50, 65/35, and 80/20 by weight. Portions of yarn samples were sectioned and photomicrographs were made. The radial distribution of the blend compo nents have been characterized by a "migration index." It has been found that the initial moduli of component fibers influence the migration of fibers and also the abrasion resistance of fabrics woven from these yarns.
Contribution to the Study of the Porous Structure of Polyacrylonitrile (PAN) Fibers The Effects of Heat Treatments
Authors: Sotton M. , Vialard A.M.
Published: March 2007

The porous fraction of PAN fibers, as shown by the formation in situ of silver sulfide, consists of radial paths which may or may not be associated with different distributions of micropores. The radial paths generally originate from microlobes or surface faults. The size of these porous zones, their number, and their mode of distribution in the structure itself are generally affected by technological operations involving tension and heat treatment. During the dry heat treatments, the fibers have a tendency to collapse, with a simultaneously decrease of the void sizes and appearance of new gaps of the same sort that characterized the original sample. The wet-phase treatments are usually accompanied by swelling of the fibers, limited when fibers are maintained at constant length. The introduction of water molecules into the struc ture produces distortions in the ordered zones and the structural rearrangement that results eliminates the initial porosity but leaves many fine micropores which are localized in the periphery of the fibers. This latter effect can be compared to a fiber-skin rupture.
Making Cotton Magnetic
Authors: Thibodeaux Devron P. , Baril Albert
Published: March 2007

Research has been conducted to develop techniques for imparting ferromagnetic properties to cotton fibers. This work was done so that greater magnetic force to fiber weight ratios ( Fm/W) could be obtained than were possible with fibers treated paramagnetically. The more promising of the techniques developed included spraying cotton fibers with suspensions of either finely divided iron or nickel particles in polyethylene oxide-benzene polymer solutions or with micron size carbonyl iron powder dispersed in an oleic surfactant solution. Evaluations of treatment effectiveness and uniformity were made using Faraday magnetic susceptibility measurements and scanning electron microscopy. It has been shown that add-ons of ferromagnetic material of about two percent give Fm/W values of approximately seven.
The Mechanism of Swollen State Formaldehyde Crosslinking of Cellulose
Authors: Smith F.R.
Published: March 2007

The formation of crosslinks depends on resonance stabilization of carbonium ion centered on the methylene carbon. The rate of formaldehyde add-on is increased by increasing hydrogen ion activity and by including an alcohol in the formaldehyde-acid solution, thus making hemiformal appear to be the most active formaldehyde source.
Dynamic Mechanical Properties of Rhinoscerous Horn Keraton in the Frequency Range 2-20 KHz
Authors: Dunlop J.I.
Published: March 2007

A method is described for measuring the elastic modulus and loss tangent of rhinoscerous horn keratin in the frequency range 2 20 kHz. The technique is based on the forced resonance of a composite made of a specimen of rhinoscerous horn keratin cemented between two matched aluminum bars. Modulus is determined from the resonant frequency and loss tangent from the band width.

Elastic modulus was found to be 5.7 8.0 × 1010 dynes/cm2 along the fiber direction, and 3-4 × 1010 dynes cm2 at right angles to the fiber direction, for samples at 9% regain and room temperatures. Loss tangents were found to be 2-4 × 10-2 along the fiber direction and 3-6 × 10 2 at right angles to the fiber direction.
Length of Methylene Bridges in Cellulose Formals Made by Reacting Soda Cellulose With Dihalomethanes and With Bis(halomethyl) Ethers
Authors: Guthrie John D. , Heinzelman Dorothy C.
Published: March 2007

Methylene bridges having an average length n ranging from 1.04 to 1.21 were introduced into cellulose by reaction with dibromomethane or with dichloromethane under strongly alkaline conditions. Similarly, bis(bromomethyl)ether or bis(chloromethyl)ether gave n values ranging from 2.25 to 2.72. Repeated treatments with dibromomethane gave formaldehyde contents leveling off at 17 to 18%, or a D.S. of about 2.
Sodium Cellulosate and Diethylaminoethylcellulose as Substrates for Modification of Cotton with Epoxides
Authors: Berni R.J. , Benerito Ruth R. , Soignet D.M.
Published: March 2007

Sodium cellulosates containing up to 1.8 milliequivalents Na+ per g fabric were prepared by reacting methanolic solutions of sodium methoxide with solvent exchanged cottons which had been preswollen in water, dimethlformamide or in 23% aqueous NaOH. These sodium cellulosates were reacted with five difunctional epoxides in t-butyl alcohol or in perchloro ethylene. Fabric properties were compared with those obtained when the five epoxides were reacted with diethylamino ethyl celluloses (DEAE-cottons). DEAE-cottons were prepared in nonaqueous media by reacting the sodium cellulosates with β-chloroethyidiethylamine in t-butyl alcohol solutions. The free amine form as well as the hydrosalt form of DEAE- cottons was used as substrate for epoxide reactions. Fabric properties were also compared with those obtained with the hydrosalt form of DEAE-cottons prepared in aqueous media and with those resulting from the reaction of epoxide with cotton pretreated with aqueous XaOH.
Finishing of Textile Fabrics by the Thermotex Process
Authors: Rusznák I.
Published: March 2007

Continuous textile dyeing and finishing processes are strongly influenced by the temperature differences between liquor and fabric during the padding operation. The temperature of the padding solution is usually higher than that of the fabric, the difference being as much as 60°C. The temperature of the fabric does not reach the temperature of the solution throughout the entire padding process. Important changes in wetting, penetration, and reactivity occur as a consequence of preheating of the fabric. Chemical and physical changes in cellulosic fibers can be shown to occur after short thermal treatments. New methods for the dyeing and finishing of cotton fabrics have been made possible by the Thermotex Process.
Studies on Dye Fixation Using Hexahydro-1,3,5-Triacryloyl-s-Triazine
Authors: Amin Sanaa A. , Hashem M.S. , Kamel M.
Published: March 2007

The effect of the basic skeleton of the molecule as well as the type and number of nucleophilic groups on fixation of dyestuffs on cellulosic fibers using hexahydro-1,3,5-tri-acryloyl- s-triazine is studied. It is shown that the different groups react in the order amino group > imino group > hydroxyl group. Presence of three or at least two nucleophilic groups is generally essential for higher degree of fixation.