Textile Research Journal

Cotton samples were analyzed after water washing or mechanical cleaning to com pare the effects of such processes on chemical content of the bulk cotton. Water extracts of the samples were analyzed for organic carbon content by measuring total organic carbon and for ionizable species by measuring conductance. Total solids content and pH of the extracts were also determined before and after washing or cleaning. The level of noncellulosic organic compounds in the bulk samples was evaluated by extraction of the cotton samples with 2-amiftoethanot. The effect of washing and cleaning on volatiles evolved from the bulk samples was compared by gas chromatography/mass spectrometry measurements. All analyses of water extracts showed only slight changes after mechanical cleaning on a Shirley Analyzer, while large decreases in all values were found after water washing. Analyses of water extracts of cottons washed in the laboratory gave results close to those obtained on a "medical grade" cotton.

The influence of specific items of gin machinery and moisture on the fine dust content of ginned lint, nonlint content, and composite grade was investigated using eight cottons, six machines, and four levels of moisture content. Data from this study indicated that initial cotton conditions, gin machinery, and fiber moisture content each had a significant effect on the amount of fine dust remaining in the ginned lint, nonlint content, composite grade, trash grade, grayness, and yellowness. Generally, this investigation showed that fine dust in ginned lint decreased as composite grade and the level of lint cleaning increased and the fine dust decreased as the moisture content during processing decreased. Also, the fine dust content for a specific bale of cotton cannot be satisfactorily estimated from measurements currently made on lint such as composite grade, nonlint content, and high volume instrument mea surements.

A new, high-speed, automated instrument for measuring foreign matter including microdust and trash in bale or processed fiber is described. The method uses aero- mechanical release and separation and electro-optical sensing for microdust, trash, and lint. Data are provided proving the correlation of an experimental prototype gin monitor's readings with readings of other methods. Example data for both microdust and trash are given for both gin and textile mill cleaning machinery performance.

Tests were conducted at USDA laboratories in Lubbock, Texas, Stoneville, Mis sissippi, and Clemson, South Carolina, and at Cotton Incorporated, Raleigh, North Carolina, to evaluate lint retrieval at ginning. Lint retrievers are designed to recover spinnable fibers from lint cleaner waste and blend them into the lint stream. This research evaluated the fiber properties and spinning performance of cottons from two growing regions ginned with and without lint retrieval. Test size was eighty half-bale lots.

Cotton from the same field was harvested and ginned in two replications three weeks apart. The ginning treatments consisted of using a conventional machinery sequence without fiber retrieval and recycling, and using the same machinery se quence with continuous fiber retrieval recycling. Ten half-bale batches from each harvesting were processed using each ginning treatment. Samples from each batch were tested for differences in raw cotton properties, yarn manufacturing performance, and chemical finishing. Bale weights were improved 2.2% by the retrieving and re . cycling process. More of the bales from the with retrieval and recycling process were reduced in grade because of grass in the sample than from the control bales. There were no significant differences in the quality and performance factors of the raw cotton and yarn which could be attributed to differences in the ginning treatments. Some of the factors evaluated did show statistically significant differences due to the interval between harvest dates.

Experiments were conducted to evaluate the effects of a fiber retrieving process at the cotton gin on fiber and yam quality and spinning performance of machine- stripped cotton. The retrieving process recovered about 75% of the fiber normally wasted by the gin-type lint cleaners, and returned this fiber to the bale concurrently with ginning. The process had no effect on lint classification, but increased bale weights by 4.1 to 5.4 kg and bale loan values by $3 to $4. Retrieved fiber was significantly lower in quality than conventionally cleaned fiber, but the return of this small amount of fiber to the bale had only minor effects on overall fiber quality. Yarn tenacity and spinning potential were reduced slightly by the retrieving process in one experiment, but unaffected in another experiment. The retrieving process had no significant effect on other spinning performance and yarn property measurements, percentage of comber noils, combed sliver properties, or dye-uptake characteristics of knitted fabric.

Progress has continued on the SRRC no-twist yam system since the work was originally announced at the 1979 Natural Fibers Textile Conference. Various me chanical modifications that have allowed the production rate to reach 1.5 m/second (100 yards/minute) are discussed. Yam properties of no-twist yarns made from three different staple length cottons at varying production rates are compared to ring spun and open-end yarns from the same cottons. These results show that the no-twist yams compare favorably in uniformity and grade, but are weaker with lower elongation than the ring or open-end yams. Properties for knitted jersey fabrics from selected no-twist yarns compare favorably with ring and open-end fabrics. Work is continuing on the experimental no-twist yarn system.

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.

Outdoor fabrics suitable for tentage, tarpaulin, and similar uses were produced from cotton yarns reinforced with glass fiber. The yarns were made on a conventional ring spinning frame modified to insert continuously a multifilament core, and con tained from 17% to 57% glass fiber. The experimental yarns were evaluated as filling in common warps. Canvas fabrics in a weight range of 200 to 270 g/m² were woven. The fabrics were given a typical commercial finish for 100% cotton which included mineral dyeing and the application of a wax emulsion to impart water repellency.

Fabrics produced from the cotton/glass filiment core yarns were considerably stron ger than comparable 100% cotton fabrics. The experimental fabrics also lost less strength in accelerated weathering tests. Glass fiber reinforced fabrics treated with a flame retardant had better flammability resistance than 100% cotton fabrics. Ap pearance, hand, and finishing characteristics of the core yarn fabrics were similar to those of the all-cotton fabrics. Use of the glass fiber reinforced yarns could result in the production of stronger, lighter weight outdoor fabrics with the many desirable inherent properties of cotton.

Traditional wool printing methods are described, stressing the two main problem areas of fabric preparation by prechlorination and print development in steamers; techniques to overcome or minimize these problems are discussed. Difficulties as sociated with special styles such as discharge and resist printing are also critically examined. Growing interest in blend printing presents special problems, and methods of overcoming these in the case of wool/polyester and wool/cotton blends are given. Recent developments in the field of transfer printing all wool fabrics are also described.