Hugh M. Brown

Effect of Colloidal Silica Treatments on Cotton Processing Characteristics and Yarn Quality

to develop maximum strength in treated yarns is less than that required for untreated yarns. It has also been reported [4] that colloidal silica has been successfully used on a commercial scale in the manufacture of combed yarns. Studies on wool [2, 11], where colloidal silica compounds were applied, indicated that the increased interfiber friction permitted the spinning of high-strength woolen and worsted yarns, together with a reduction in waste, ends down, and mending costs. Though the findings to date on the eff ects of

Measurement of Triboelectric Response of Raw Cottons

By use of a novel commutator method, triboelectric potentials produced by rubbing cotton with various materials have been measured by comparison with known D.C. potentials. Results are given here for fiberboard (phenolic resin laminate, fabric base), cork roller material, syn thetic rubber roller material, Lucite, polystyrene, glass, and cellulose acetate sheet, used as rubbing materials on three varieties of cotton and trash extracted from baled cotton. The purpose of this study was to learn if the sufficiently great differences in triboelectricity produced by cot tons and trash could be used practically in the electrostatic cleaning of cotton.

Measurement of Dielectric Constant and Dissipation Factor of Raw Cottons

By use of a suitable capacitance bridge and special condenser, the dielectric constant and dissipation factor at a frequency of 200 kc./sec. were measured for several varieties of cotton and for several types of trash removed during processing. Measurements were made at 70°F and 45%, 55%, and 65% R.H. The results are in fair agreement with those obtained by other workers.

Measurement of Fineness of Cotton by Air-Flow Methods

Using 7 varieties of cotton harvested at different times to give an extremely wide range in fiber development, a study was made of the air-flow method of measuring fineness and maturity of the lint. The data show that when porosity meters are calibrated in units of weight per unit length of fiber (i.e., fineness) the curves for different varieties of cotton are quite different. This is due to the fact that resistance to air-flow through a fiber plug correlates more closely with the surface area of the fibers composing the plug than with their fineness. This surface area varies with variety and maturity, independently of the fineness of the cotton. Using a plug of constant weight and volume made of fibers having a constant density enables the use of a simple theory which predicts essentially the actual variation of air-flow with both variety and maturity of the cottons tested. Two quite different types of air-flow apparatus are shown to give similar results that are more consistent with the specific surface † of the several cottons than with the fineness of the fibers. For several cottons, the air-flow data published by the U. S. Department of Agriculture for the 1948 crop are compared with the previous 10-year averages for fineness which had been measured by counting and weighing the fibers.

A Method of Reducing Card Waste

It should be pointed out that cotton costs approximately 350 per pound as against 60 per pound for fly and 181/2¢ per pound for strips. A saving of approximately

Sliver Evener for Roving Frames

35,000 per year is the expected result of converting 100 cards. At Swift Manufacturing Co., plans are being made to go still further in other card rooms, now that this phase of the work has been completed. New tests will be made on different types of work which are at present running in these rooms.

A Continuous Method of Measuring Yarn Modulus

Evcnness of yarn is one of ’the greatest (’()lU’crns in the entire textile manufacturing process. Much (are has to lw exerciSt’d to term picker laps that are unifornt from machine to machine and alonK the tap from each machine. ()ut-c>f-siie Lys ire customarily s<*parated and handled ditTerl’ntly from those within certain tolerances. Though the variation in slivrr caused by the remaining variatiott in taps is somewhat minimized by doubting and drafting :tt the drawing frame, there still remains considerable variation in the sliver fed to khe roving frame, where this variation occurs aKain :trncm~; clit~~·rrnt slivers and alonK any Kivt.’n sliver. In view of this situation, it seems that much

Effect of Colloidal Silica Treatments on Sizing and Finishing Characteristics of Cotton Yarns1

Though continuous testing may have several advantages over break tests, some of the machines for doing it have been somewhat complex mechanically, and some have had impractical features. In case the yarn is fed in and out of a constant tension loop by means of gripping rolls, the rolls become worn and polished and allow slippage of the yarn in spite of high pressure applied to the rolls. If slippage is recorded as elongation, the result may be subject to large errors. It is believed that in the machine to be outlined in

Improvements in Card Operation

Cotton in lap form was treated with a colloidal silica compound, and together with an untreated lap was processed into 15/1, 36/1, and 50/1 yarns. Samples of these yarns were used for control, for mercerizing, for bleaching, and for dyeing. Analyses of ash content were made on these four sets of samples. In addition, other samples of the yarns were used to assess the reaction to slashing, desizing, and abrasion. In general, the presence of colloidal silica, on medium and fine carded yarns, did not affect the operations of mercerizing, bleaching, and dyeing. Yarn strength differences between treated and untreated samples were of the same order after as before each of these chemical processes. Quantitative tests (ash-content analyses) to determine the effect of these processes on the permanence of the colloidal silica on the fiber were inconclusive.

Clemson Pretwister for Roving Frames

disadvantages outweigh the advantages of the method, but, in the absence of any definite information, a study of the problem is now being undertaken at Clemson. This is a very preliminary progress report on the work begun last summer. It seems fairly obvious that the loading of the flats while in contact with the cylinder would be quite different when run opposite to the usual direction. Also, the type of material brought out on the flats should be different for the two directions. When