Knitted Cotton Research Articles

Colour Difference Of Illuminant Metamerism

Fifty-five metameric sample pairs were prepared using computer-predicted recipes from six different colour centres using cotton knit fabric. The colour difference of each sample pairs was measured using a datacolour Elrepho 2000 under the reference illuminant D6s, and test illuminant A and TL84. The colour difference of a sample pair under a specific illuminant is formed from three different components i.e. lightness, chroma and a* b* difference. Metameric colour difference should be attributed to the CIELAB a* b* difference and to a less extend of chroma difference but not to the lightness L* difference under the test illuminants.

Effect of Pre-Existing Dyes and Fabric Type on Cellulase Treatment of Cotton Fabrics

Fabric weight loss through cellulase treatment of six different cottons depends on mercerization, yarn size, and fabric structure. Weight loss decreases in the order of Ne = 60 mercerized > Ne = 60 nonmercerized ≈ Ne = 40 mercerized > Ne = 40 nonmercerized knit fabrics > Ne = 20 ≈ Ne = 10 nonmercerized woven fabrics, indicating increased enzymatic hydrolysis on mercerized cotton knits with smaller yarn size. The effect of pre-existing dyes on cellulase activity is examined by measuring the difference in weight reduction for mercerized and nonmercerized cotton knits previously dyed with direct, reactive, and vat dyes. All six dyes in this study inhibit the cellulase reaction, and the degree of inhibition depends on the dye class. The concentration of dyes on fabric as estimated by K/S proves to be the most critical factor governing resulting weight losses. The planar structure of vat dyes with larger molecular sizes than indigo dye seems to play an important role in their inhibitory effect. Compared with monoreactive, direct, and vat dyes, the largest inhibitory effect is with bifunctional dyes, implying that the crosslinking property of bifunctional dyes is related to cellulase hydrolysis. This suggestion is further supported by the small reduction in weight after cellulase treatment of DMDHEU-treated cotton fabric. A model is proposed to explain the slower progress of enzymatic cleavage on crosslinked cellulose fibers.

Selected Properties of Predominantly Cotton Staple-Core Knitted Fabrics

This study of single-jersey knit fabrics is the first to examine the basic properties of staple-core knits. Prior studies revealed certain functional and aesthetic advantages of woven staple-core fabrics when compared to 100% cotton or intimate-blend fabrics of the same construction. In this study, nominal 20s count staple-core yams have been spun on a ring spinning frame that incorporates patented modifications. The staple-core yams contain a high tenacity polyester core and a cotton sheath comprising two-thirds of the yam. The fabrics are knitted on a single-feed jersey knitter with a 88.9 mm (3.5-inch) diameter, 20-gauge cylinder. Fabric properties are examined after five home-laundering cycles, in the greige state, after scouring, and after scouring and heat setting. The staple-core knits are stronger, less permeable, and significantly more abrasion resistant than the cotton controls. They also show less differential shrinkage and look consistently better than the controls after laundering. Greater spirality is evident in the greige staple-core knits than in the cotton knits, but the skewness of all fabrics decreases with additional processing. Skewness is substantially eliminated by substituting S- for Z-twist staple-core yam. Relaxed S-twist staple-core fabrics are also denser and greatly more abrasion resistant than comparable Z-twist knits. This suggests that a reduction of yam torque might further improve the superior properties and performance of staple-core knits. Additional study is required to optimize heat setting procedures and provide meaningful discussion of the dimensional stability of staple- core knit fabrics.

Lateral Migration Control During Drying Using Methyl Cellulose

A method developed previously was used to quantitatively assess lateral migration during controlled drying. Methyl cellulose in aqueous solution, which has a unique property of forming a gel when heated, was used to control lateral agent migration during drying of knitted cotton fabrics impregnated with crosslinking reagents. During drying, the reagent solution formed a gel and significantly restricted movement of water and reagents in the capillaries of the fabric. Effects of methyl cellulose concen tration on the rate and extent of migration were evaluated.

The Engineering of Cotton Knits and their Potential in the Next Decade

The Engineering of Cotton Knits and their Potential in the Next Decade

Dimensional Stability of Ramie, Cotton and Rayon Knit Fabrics

Dimensional stability of ramie jersey knit fabric was compared to that of cotton and rayon jersey fabric. Three experimental laundering procedures were employed: hand washing with flat drying, machine washing with flat drying, and machine washing with tumble drying. Experimental fabrics knit from ramie, cotton, viscose rayon, and high wet modulus rayon and from 50/50 mixtures for each fiber were laundered five times using each of the three laundering procedures. Major findings were that ramie and ramie-cellulosic knits have better dimensional stability than knits containing only cotton and rayon. Ramie knits also exhibit little progressive shrinkage and growth. Both cotton and rayon knits exhibited progressive shrinkage in the wale direction and progressive growth in the course direction. In general, method of drying was found to be a greater factor in maintaining dimensional stability than was method of washing. Tumble drying after washing was found to result in less course-wise growth than flat drying.

The Engineering of Cotton Knits and their Potential in the Next Decade

The Engineering of Cotton Knits and their Potential in the Next Decade

Prediction of Finished Relaxed Dimensions of Cotton Knits— The Starfish Project

Shrinkage of 20 different cotton knit fabrics was followed over ten cycles of relaxation using two methods of relaxation. The first method used a standard washing and tumble drying procedure, while the second used washing for only the first cycle; for the second and subsequent cycles, fabrics were merely wet out by rinsing before tumble drying. The two methods returned essentially the same shrinkage results within experimental error. Evidence was found for at least two separate underlying relaxation processes. In the length direction, the two processes are complementary, resulting in gradual progressive shrinkage. In the width direction, the two processes apparently worked in opposite senses, leading to greater uncertainty in the results and no marked trend in shrinkage over a number of cycles. The simplified rinse and tumble procedure has been adopted as the standard relaxation method for the Starfish project. At least five cycles seem to be necessary to approximate the fully relaxed state.

Crimp and Resilience of Yarns in Knit Cotton

Crimp and Resilience of Yarns in Knit Cotton

Prediction of Finished Weight and Shrinkage of Cotton Knits— The Starfish Project

The "Starfish" project is a long term program of applied research that attempts to provide a sufficiently rigorous working method and a sufficiently comprehensive data base so that a rational system may gradually be developed for reliably predicting the shrinkage and dimensional properties of finished, knitted cotton fabrics. This intro ductory report presents the general outline and philosophy of the project, and sum marizes some of the main areas of progress after the first five years, so that subsequent publications of detailed results may be seen in context.

Mind in Matter: An Introduction to Material Culture Theory and Method

Mind in Matter: An Introduction to Material Culture Theory and Method

A STUDY ON THE CRITICAL WATER CONTENT OBTAINED BY SENSARY TEST OF MOIST FABRICS

There is a close relation between damp or oppressive sense and water content of fabrics. The differences in the critical water content of damp sense of fabrics among fibers have been suggested as one of major factor when we discuss comfortable use of fabrics. The relation between the subjective rating of critical water content of damp sense and the experimental results of fabrics was mainly discussed in this paper.That is to say, results of sensary test of four kinds of knit fabrics, polyester, acrylics, wool and cotton, on damp and oppressive sense were compared with those measured by both the sliding resistance of water sorbed fabrics to a metal, from which the clingy forces were assessed, and the changes of the temperature and the heat flow in drying. The relationship were mainly investigated between the critical water content of damp sense, the effects of water content to the clingy forces and the temperature or the heat flow. It was found that the critical water content of damp sense was characterized by the critical water content where the clingy force showed the remarkable increase, and the so called the second critical water content in the falling-rate period of drying.

Sonic Pulse Velocity in Fabrics: Is it Related to Abrasion Resistance?1

Sonic velocity C was determined in some woven and knit cotton and cotton/polyester fabrics by the pulse-propagation technique, and C2 was compared with rate of weight loss produced by the Accelerotor method of measuring abrasion resistance. Changes in C 2 within a set of fabrics accompanied changes in abrasion resistance produced by durable- press finishes. Between sets of fabrics given different treatments, it was not possible to make direct comparisons be tween C2 and abrasion resistance; other factors such as stiffness must be considered. There was an indication that sonic velocity measurements might be related to fabric hand.

Selection of Optimum Fiber Properties for Cotton Knits

The effects of fiber fineness, strength, and length on the properties of cotton and cotton/polyester blend knitting yarns and knitted fabrics were determined. Five cottons ranging from 3.9 to 5.2 in Micronaire reading, 38.1 g/tex to 48.1 g/tex in strength, and 31/32-in. to 1 1/8-in. staple length were evaluated. Yarns spun from a fine, medium-staple-length cotton were the most uniform, had the fewest imperfections, and compared favorably strengthwise with those spun from the strongest cotton. Differences in fiber properties had no significant effect on fabric abrasion or shrinkage resistance. However, fabrics produced from the high-strength cotton were the strongest both in the grey state and after resin finishing. Blending of 20% to 40% regular-tenacity polyester fiber with cotton reduced yarn strength, whereas similar blends using high-tenacity polyester resulted in increased yarn strength. Fabrics produced from the cotton/polyester blends generally had better abrasion resistance, less shrinkage, and smaller strength losses after resin treatment than the all-cotton fabrics.

Analysis of Agent Migration during Durable-Press Treatments of Knitted Cotton Fabric

A method was developed to quantitatively assess lateral agent migration during controlled drying of knitted cotton fabrics impregnated with cellulose crosslinking agents. The influence of inorganic salts and a nonionic surfactant on migration was investigated. Reasons for this influence are indicated. Relative migration rates were established and results were applied to phenomena occurring during conventional drying conditions. Results are correlated with qualitative evidence of migration from resistance of crosslinked fabrics to direct dyes.

Comparison of Preshrinkage Treatments for Crosslinked Knitted Cotton and Cotton Blends

Laundry shrinkage in knitted fabrics of cotton or cotton-polyester was reduced by a combination of chemical cross-linking and preshrinkage treatments. Preshrinkage during finishing was induced by compression either before or after crosslinking, and by either wet or dry relaxation after crosslinking. The effects on fabric loss in processing, strength, fabric structure, and recovery from deformation were compared for each combination.

Rapid Determination of Bromine-Containing Flame Retardants on Fabrics

Bromine-containing flame retardants on woven and knit polyester, polyester/cotton, and cotton fabrics can be deter mined in less than ten minutes by nondispersive x-ray fluorescence. The sample is prepared by cutting a disc from the fabric with a die. The disc is weighed and then counted with commercial x-ray instrumentation employing an Am-241 irradiation source, a prolortional counter, and a single channel analyzer. After the average count is corrected for the background count obtained with untreated fabric of the same type, the milligrams of bromine are read from a calibration curve and the percent bromine is calculated. A modificaticm of the procedure alluwed nondestructive analyses of fabrics which were then used for burning rate studies. Phosphorus and chlorine do not interfere.

The Role of Glass-Transition Temperature of Polymeric Additives in Durable-Press Finishing of Knitted Cotton

Polyacrylate and polyurethane additives to crosslinking treatments of circular knitted cotton fabrics are discussed. The effect on textile properties of varying glass-transition temperature in these polymers from -32 to +40°C is examined. Dimensional stability and strength of the finished fabrics are independent of polymer glass transitions. Fabric stiffness and resistance to flat abrasion increase and recovery from tensile strain decreases, with increasing glass-transition temper ature of the polymer additives.

A General Relationship between "Easy Stretch" and Break Extension for Woven and Knitted Cotton Fabrics, Including Effects of Resin Setting

A most significant correlation between "easy stretch" (∈∞) and break extension (∈ b) has been observed for cotton woven fabrics, also consistent with measurements on knitted fabrics. Assuming that the reason for this correlation is an over-all similarity of the stress-strain curves, a master curve equation is derived, whose "individual" parameter is settled by force and extension at break.

Recovery from Tensile Strain in Knitted Cotton Fabric after Cross-Linking

Extension under tensile load and recovery from extension was studied on a jersey knit cotton fabric after cross-linking treatments. The cross-linking reduces breaking strength and elongation-at-break, with only small changes in the load- elongation curve up to the break point. Set resulting from a high load is reduced by an amount approximating the reduction in extension; actual recovery is increased only slightly. Length increase from reheated loading can be reduced by cross-linking, but the extent of reduction is also influenced by noncross-linking additives.