Rayon Yarns Research Articles

A Theory of Commercial Yarn Testing

A method has been devised for the application of the theory of the three-element shear model of Eyring and coworkers to textiles which does not necessitate the location of the "basic spring line" and thus is readily applicable to both yarn and fiber tests and to the commercial inclined-plane and pendulum-type testers. It is also applicable as a first approximation to those textiles which do not possess a "basic spring line" as such. The method employs the conven tional spring constants or elastic moduli but determination of the viscous constants involves the magnitude of the relaxation in constant-rate-of-elangation experiments (or the magnitude of the creep in constant-rate-of-loading experiments) from the upper envelope per interval of time. The relationship has been employed to establish the correlation between the viscoelastic prop erties of "slashed" and "unslashed" viscose tire-cord rayon yarns and also to show the identity of single-filament stress-strain relationships with those of yarns of normal twist of the same textile. The simplicity of technique which enables this method to be used as a routine labora tory test for the determination of the viscoelastic properties of textiles is an advantage over previous methods, which were often unsatisfactory from both a theoretical and an experimental viewpoint.

A Theory of Commercial Yarn Testing

A method has been devised for the application of the theory of the three-element shear model of Eyring and co-workers to textiles which does not necessitate the location of the ``basic spring line'' and thus is readily applicable to both yarn and fiber tests and to the commercial inclined-plane and pendulum-type testers. It is also applicable as a first approximation to those textiles which do not possess a ``basic spring line'' as such. The method employs the conventional spring constants or elastic moduli, but determination of the viscous constant involves the magnitude of the relaxation in constant rate of elongation experiments (or the magnitude of the creep in constant rate of loading experiments) from the upper envelope per interval of time. The relationship has been employed to establish the correlation between the viscoelastic properties of ``slashed'' and ``unslashed'' viscose tire cord rayon yarns and also to show the identity of single filament stress-strain relationships with those of yarns of normal twist of the same textile. The simplicity of technique which enables this method to be used as a routine laboratory test for the determination of the viscoelastic properties of textiles affords it an advantage over previous methods, which were often unsatisfactory from both a theoretical and an experimental viewpoint.

Mechanics of Elastic Performance of Textile Materials

The factors which affect the textile quality usually known as resilience are discussed, and a normalized co efficient is derived which quantitatively expresses the degree of resilience of textile fibers. Use of the term "elastic performance," rather than "resilience," is sug gested. The dependence of elastic performance upon the fundamental load-deformation properties of textile ma terials is considered and it is demonstrated that the elastic performance coefficient reflects the effect of immediate-elastic, primary-creep, and secondary-creep deflections. The coefficient is indicated to be applicable to all types of loading: tension, compression, bending, torsion, etc. All that is required for its calculation is a load-deforma tion diagram under uniform, controlled cyclical loading and unloading. Data are presented upon the tensional elastic per formance of two different materials—continuous filament acetate rayon and fully drawn nylon—under various magnitudes of tension loading. Variations in elastic performance with yarn geometry—that is, twist—are given for the acetate rayon yarn. The evaluation of elastic performance under com pression and other types of loading will be presented in a future paper.

Progress in Industrialization of Latin America

was all but ignored by United States scholars and businessmen. During the intervening ten years it has become a favorite theme for poptilar writers and speakers as well as academic investigators. This period has also witnessed significant developments in the industrialization of the countries to the south. Perhaps the time has arrived for a new appraisal of the subject. For years there have been some substantial manufacturing industries in Latin America. Brazil had nearly three million cotton spindles before the Second World War, and that country, as well as several others, supplied the major portion of their requirements of such articles as cotton and woolen textiles, rayon yarn and manufactures, shoes, hats, beverages, glassware, tires, furniture, and other types of consumer goods, as well as of cement, construction materials, and other capital goods. Some important assembly operations had grown up, and secondary metalworking operations were expanding constantly. Most important of all were the industries producing manufactured foodstuffs and semimanufactures, such as sugar, meats, and copper bars.

Some Experiments on the Dyeing of Nylon Yarn

SummaryDirect dyes which remain in solution in an acidified dyebath, as most do, can be dyed on nylon yarn at rates comparable with those of the same dyes when dyed on viscose rayon yarn from a neutral bath. In the absence of acid, nylon yarn absorbs direct dyes much more slowly than does viscose rayon. The rate and equilibrium absorption of direct dyes by nylon yarn is dependent upon the pH of the dyebath.Increase of dyeing temperature increases the rate of absorption of both direct dyes and acid dyes and decreases the equilibrium absorption.With direct dyes, neutral salts raise the rate and degree of dyebath exhaustion from a neutral bath and decrease both in an acid bath; the latter behaviour is also shown by acid dyes on wool or nylon.Nylon, like wool, has an acid‐binding capacity which increases with the mol. wt. of the acid for a series of organic sulphonic acids, and is lower than that of wool.Nylon yarn dyed with direct dyes exhibits dichroism when examined in polarised light. Some acid dyes produce dichroism on nylon and some do not.All the above facts are accommodated if a dual behaviour is attributed to nylon, viz. that its union with dye may result from (a) the formation of a salt link as with wool and/or (b) the exertion of residual valency forces as with cellulose.SummaryThe fastness to washing and light of nylon yarn dyed with acid dyes, direct dyes, cellulose acetate rayon dyes and chrome dyes has been compared directly with that of viscose rayon, cellulose acetate rayon and wool. Recommendations as to the potential usefulness of different classes of dyes are made.Direct dyes do not cause appreciable degradation of nylon when the dyeings are exposed. Vat dyes cause extensive degradation, which takes place more rapidly than is the case with cellulosic fibres and is accompanied by similarly rapid fading of dye.Whereas fading of dyes occurs in the presence or absence of oxygen, an atmosphere containing oxygen is essential for photodegradation of the fibre.

Chemical Characterization of Rayon Yarns and Cellulosic Raw Materials.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemical Characterization of Rayon Yarns and Cellulosic Raw Materials.C. C. Conrad and A. G. ScroggieCite this: Ind. Eng. Chem. 1945, 37, 6, 592–598Publication Date (Print):June 1, 1945Publication History Published online1 May 2002Published inissue 1 June 1945https://doi.org/10.1021/ie50426a025RIGHTS & PERMISSIONSArticle Views87Altmetric-Citations40LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (863 KB) Get e-Alerts

Viscose Rayon: Stress-Strain Properties

Measurements were made of the strength and stretch of viscose rayon yarns at values of relative humidity ranging from 43 to 74%. It was found that the strength decreases and the stretch in creases as the relative humidity is increased. Both effects are ap proximately linear in the region observed. The change in strength is 2.58 grams, in stretch .047%, for each 1% change in relative hu midity. Stretch-load diagrams are shown, and it appears there that the "yield" region decreases and the "work hardening" region in creases with increased relative humidity. Correlation is found to exist between strength and stretch of individual specimens. The best estimate of the coefficient of cor relation is + 0.185.

A Study of Warp Size Distribution on Continuous Filament Bright Viscose Rayon

Evidence obtained by means of a study of cross-sections of sized rayon yarn is presented to show the marked difference in distribution on the yarn between the gelatin-glue class of size and the converted starch class. The effect of relative viscosity of the size mix is illustrated. The different behavior of yarns from different manufactures is noted, and the effect of can-drying on the yarn cross-section is discussed.

A Suggested Standardization of Breaking Strength Tests for Rayon Yarns

A Suggested Standardization of Breaking Strength Tests for Rayon Yarns

Relation between the twist and certain properties of rayon yarns

Relation between the twist and certain properties of rayon yarns