Scoured and slack-mercerized fabrics were treated with dimethylol ethylene urea, methylated methylol melamine, and formaldehyde. Fabries with differences in resin add-on and differences in stretch during the cure were examined. Changes in tensile modulus caused by addition of resin were smaller than those caused by stretching during treatment. The elongation at break was greater for the slack-mercerized than for the scoured fabries. Also, the recovery from strain during the testing was greater for the slack- mercerized than the scoured fabric. Recovery increased with add-on for both the basket and the plain-weave fabrics. Stretch during treatment had-only minor effects on strain recovery during the testing. The correlation coefficients of fiber strain recovery to fabric strain recovery are lower than those of fabric strain recovery to wrinkle recovery. The correlation coefficient of the latter is increased if recovery is a function of both strain and stress rather than of either used separately.

The variation in the twist multiplier for maximum yarn strength in terms of the fiber properties of length. weight fineness, and uniformity of tenacity along bundle length is inferred from data based upon 15 1, 30, 1, and 40/1 yarns of a series of cottons having widely different fiber properties. The optimum twist multipliers that were calculated (1) from the above three fiber parameters (i.e., the tenacity-length uniformity hypothe sis); (ii) from the length and fineness, and (III) from the fiber length alone are com pared to the optimum twist multipliers detemined from the yarn tenacity vs twist curves. The tenacity-length uniformity hypothesis and the Sullivan theory are com pared by utilizing single cotton fiber properties. Considering all comparisons, the cor relation coefficients for theoretical to nommal values of optimum twist range from 0.64 to 0.96. Utilization in yarn twist of the ratio denoting uniformity of tenacity along bundle length in the tenacity-length uniformity hypothesis and of the ratio of single-fiber tenacity transfer in the Sullivan theory is illustrated.

The fiber properties and processing behavior of gin-dried cottons were determined on Deltapine 15 cotton from the Mississippi Delta area. Several comparisons were made of hand-harvested and machine-havested cottons. Growth conditions had an important influence on the short-fiber content and spinning properties. High short-fiber contents in ginned lint persisted after processing into card sliver. Examination of fibers from length arrays indicated a preferential breakage of fine and immature fibers during ginning and cleaning. At spindle speeds that cause a large number of ends to break, the number of breaks during each hour was related to the running hour of the doff. The spread in number of breaks per doff decreased as number of end breaks decreased. End breakage in spinning increased with gin drying for hand-harvested cotton, but had a minimum at an intermediate drying level for machine-harvested cotton. Yarn grade and strength for both types of harvesting decreased with gin drying. Overdried lint from center segments of bales when processed without preconditioning had higher end breakages than lint from the outer segments.

Fabrics made from lint cotton subjected to twelve combinations of ginning practices —seed cotton cleaning, lint cleaning, and drying levels—were tested as gray, bleached, and resin treated fabrics. The seed cottons dried to the lowest moisture level before ginning produced the weakest gray fabrics. Bleaching caused no accentuation of their differences in breaking and tearing strengths which could be associated with the ginning practice since strengths of all twelve fabrics were reduced about the same amounts. Resin treatment and laundering decreased the differences in strengths among fabrics. Density of cellulose was slightly higher for the three lots dried to the lowest moisture level. Moisture regains of the bleached fabrics were essentially equal. Alkali centri fuge swelling values were more closely associated with fiber fineness than with the ginning practices. Among the fabrics, differential dyeing detected differences asso ciated with fiber fineness but not with ginning practices. Degree of polymerization was reduced by bleaching but showed no consistent relation to seed cotton treatment. Inconsistencies among samples within groups do not permit conclusions to be reached as to effects of seed cotton cleaning or lint cleaning.