Influence of Growth Period on Neps in Cotton

Abstract

The interactions between picking dates, locations, and varieties were studied to evaluate the effect of growth period on neps in ginned lint, yarn, and fabric. Five harvest intervals were selected, and the cotton yield increments between intervals were used to provide five levels of maturity. Neps in raw cotton were measured by the USDA-AMS web nep test and microscopic examination of card web, imperfections in the yarn ascertained by the Uster instrument, and neps in woven fabric counted by dyeing procedures. Results showed that growth period has a significant impact on the number of neps and other imperfections found in lint and manufactured yarns and fabrics. As a general rule, cotton grown early in the season will produce yarns and fabrics with a lower number of imperfections than cotton grown late in the season from the same field.Neps are small knots of tangled fibers created during the harvesting, ginning, and yarn manufacturing phases of production. They occur in varying numbers in most cotton yarns and cause considerable concern to most persons interested in yarn and fabric quality. Neps may be a source of trouble in manufacturing, may detract from the appearance of the woven fabric, and may not dye properly [4,9]. Seedcoat fragments, along with neps, affect not only the quality of the finished product but are also probably responsible for some of the &dquo;ends down&dquo; in spinning [6].There is some evidence that the number of neps in yarn increases with increasing fiber length, decreasing fiber weight per inch, and increasing percentages of thin-walled fibers [5]. Ginned lint from machine-picked defoliated cottons may have more neps than the lint from undefoliated cottons, and fibers from late harvested cotton are more susceptible to nepping than fibers°from early harvested cotton [3]. This has been attributed to the likelihood that the defoliated and late harvested cottons are more immature.Field studies of boll development during [1977][1978][1979][1980] showed that air temperature was the primary environmental variable controlling the relative rate of cotton lint accumulation, with a smaller but signi6cant moisture stress influence for the range of conditions encountered. Fiber micronaire was chiefly dependent on temperature, but plant moisture stress decreased the sensitivity of micronaire to temperature. Fiber strength was strongly influenced by temperature, with a sipificant temperature-genetic interaction [10].In new experiments, we studied the interactions between picking dates, locations, and varieties to evaluate the effect of growth period on neps in ginned lint, yam, and fabric. We sought this information to help control to some degree the number of neps created during harvesting, ginning, and mill processing and to aid breeders in developing varieties with a low potential for neppiness.

Minimizing Immature Fiber and Neps in Upland Cotton

“…More neps (in cotton with no lint cleaning) and immature cotton was associated with earlier harvest aid treatments across all experiments (Table 4). The number of neps was negatively correlated with linear density ( r = −0.83), maturity ratio ( r = −0.63), and micronaire ( r = −0.74) indicating that production of immature or low linear density fiber was most likely the reason for increased neps (Anthony et al, 1988; Dever and Gannaway, 1988; Hebert et al, 1988; Mangialardi et al, 1987). Upland cotton fiber with maturity ratios < 0.85 or a micronaire‐value <3.5 are generally considered immature.…”

“…Immature fiber and neps even in small amounts are undesirable (Ethridge and Simonton, 2004) as they decrease mill processing efficiency and ruin the appearance of finished yarns and fabrics. Immature fibers and neps absorb less dye and reflect light differently, and consequently appear as under‐dyed barred patterns and/or “flecks” on finished fabrics (Bradow et al, 1996; Goynes et al, 1997; Mangialardi et al, 1987). Rarely are there direct penalties for growers when there is high incidence of neps, their presence can however, affect overall the sources reputation when cotton arrives at spinning mills (Gordon et al, 2004).…”

Comparison of Fiber Quality Properties of Different Cotton (G. hirsutum L.) Varieties for Normal and Late Harvest Periods

“…Therefore, the uniformity index and length decrease in immature fibers and the neps ratio increases. Mangialardi et al (1987) reported that less defective yarn and fabric in terms of neps will be produced from cotton obtained at the beginning of the harvest season compared to cotton obtained at the end of the harvest season in the same field. The neps not only affect the appearance of cotton yarns and fabric, but also often lead to lower yarn strength, spinning ends down and low uniform yarn production (Van der Sluij and Hunter 2016).…”

Biodegradation and Biodeterioration of Some Natural Polymers

“…The presence of the sub-microscopic system of capillaries in the cellulose fibers is of paramount significance, because it is the channel of chemical reactions by which water-soluble reagents penetrate deep in the cellulose structure. More active hydroxyl groups interacting with various substances are also disposed here [15][16][17][18].…”

“…Damaging of cotton fibers, fabrics and textile products by microorganisms is primarily accompanied by occurrence of colored yellow, orange, red, violet, etc. spots and then by putrefactive odor, and, finally, the product loses strength and degrades [18][19][20][21][22][23].…”