Jai Prakash

Circularity of Cotton Fibers and the Effects of Alkali Concentration and Tension on the Changes Brought About in it During Mercerization

This paper deals with changes in the circularity of cotton fibers when slick- mercerized and under different tensions in various concentrations of caustic soda. The percent increase in circularity depends on the circularity of the raw cotton. The Adder ley method for determining the circularity can give fairly reliable results for purposes of comparison.

High Pressure Squeezing in Sizing : Performance of Cotton Yarn

Cotton yarn (40 Ne) was sized at squeeze pressures of 22 and 33.8 daN/cm2 (cor responding to 5 and 25 daN/cm) on a laboratory sizing machine. The weaving per formance of yam sized at the high pressure was better than the yarn sized at the low pressure. This improvement is attributed to increased size penetration, greater packing density, and more uniform cross sections of the sized yam.

MH Scale for Micronaire Instrument and its Limitation

It is now generally recognized ,that the values of fiber weight per unit length obtained with the help of the Micronaire instrument agree closely with gravimetric fineness only in case of American Upland cottons, for which the scale of the instrument was originally calibrated and designed. As a consistent divergency was found to exist between the flow estimates and direct estimates of fiber fineness for American Egyptian cot-

Work Done in Pulling Fibers from the Cotton Seed under Impact Conditions in Relation to Fiber Properties and Ginning Behavior

The strength of attachment of the fiber to the seed has been pointed out to be an important parameter that may considerably affect the ginning behavior of a cotton variety. In order to simulate ginning conditions more appropriately, this property was determined by pulling out fibers from different regions of the seed with an impact tester. Fifteen Indian grown cottons belonging to different species were tested by examining fifty seeds from each species ; the percentage of seeds throwing out seed coat fragments was also counted. The relationships found to exist between mean work of pulling per fiber, on the one hand, and the energy consumed in ginning these varieties in a double- roller gin, the percentage of seeds throwing out seed coat fragments, and other fiber characters, on the other hand, are presented in this paper.

Evaluation of Length Parameters Obtained with the Digital Fibrograph with Special Reference to Fiber Length Nonuniformity

The Digital Fibrograph is the latest in its family, designed to measure a more fundamental concept of length, called the span length. Its read-out features and automatic operation have done away with the operator errors in drawing tangents to fibrograms and have also quickened the determination considerably. In this investigation, a detailed comparison has been made of various length parameters obtained with this instrument with simllar characters obtained with the Balls Sorter, special emphasis having been laid on different measures of fiber length nonuniformity. In addition to this, the errors attached to various parameters measured both with the Digital Fibrograph and the Balls Sorter have been worked out. Further, a preliminary examination has also been made to see which of these two instruments give measures of fiber characteristies in better conformity with spinning performance. IT IS we)! hllmv 11 that for ~00<1 spinning performance of cotton, one of the most important properties is the length, Information ahout it is important to the textile industry for two reasons. I’irst, in disentangling orienting and straightening the fibers, starting from the .raw state, it is important to know the shortest distance to which the machines can he . adjusted in order to keep the breakage of iibers to a minimum. Secondly, the ~tren~;tl~ of the product is determined by the ease with which the fibers cross the fracture zone. For these reasons, scientists have been continuously striving to devise quicker and more accurate means of fiber length evaluation. The curve-drawing Fibrograph tir~t designed by Hertel

Suitability of the Micronaire Instrument for the Determination of the Fineness of Indian Cottons

Two methods of thickness measurements are described. The first makes use of a modified beam balance and can be used conveniently at pressures as low as 0.01 g/in.* (1.55 mg/cm2). It requires a cut sample about 10 cni square. The other is an attachment for the Instron Tester which alloivs measurements on larger samples without cutting and can be used as described for pressures as low as 0.1 g / k 2 (15.5 nig/cm2) and probably lower. I t can also be used conveniently to study thickness variation with pressure. A marked hysteresis is shown in the pressure-thickness graph ; also n permanent compression strain results from any pressure applied. This can be large in magnitude for such materials as blankets, and must be considered in relation to the end use of the fabric before any thickness measurement is niade. This permanent strain is, lion-ever, easily removed from n blanket by shaking.

Effect of Relative Humidity on the Bundle Strength at Zero and 1/8 Inch Gauge Lengths

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Studies on Luster in Textiles Part III: Contribution of Structural Elements Towards the Luster Behavior of Cotton Fibers

By using a specially designed sample holder for gripping the aligned and parallelized cotton fibers in conjunction with locally fabricated lustermeter, it has been possible to measure accurately the changes in the luster behavior of cotton fibers on slack merceri zation followed by stretching to different degrees. The differential response of cotton fibers of ten varieties to the enhancement of luster as a result of slack mercerization followed by stretching to different extents has been related to the corresponding changes in the gross morphological structure and the molecular orientation. The degree of shape improvement between unmercerized and mercerized-unstretched state of a cotton has been found to be much greater than the shape improvement from mercerized-unstretched to mercerized-stretched state, and yet the development of luster has been found to be far more pronounced in the latter case than in the former. Attempts have been made to explain this behavior in terms of the changes in the molecular orientation, surface characteristics, and convolution geometry of the cotton fibers.