Slack mercerization followed by gradual restretching to the ratio of 1.25 by a series of closely set rollers in Part I of this study was proven to be effective to stretch the individual fibers shrunken during mercerization. The effect of stretch mercerization in roving form using this technique on the mechanical properties of fibers, yams and fabrics was investigated. Stretch mercerized roving was converted into fabric and its properties were compared with the properties of three similar samples: fabric from mercerized yams, mercerized fabric, and unmercerized fabric. Fabrics woven from stretch mercerized roving possessed greater strength than the commercially yarn mercerized fabrics. The fabric produced from yarns made from stretch-mercerized roving had the lowest values of percent reductions in grab strength and tearing strength after resm treatments with DMDHEU.Mercerization of cotton fibers with strong caustic soda solution has been widely used to improve luster or dye uptake, ever since the process was introduced at the end of the last century [ 1 ]. The nature and further developments of this process are still being investigated, and new aspects were revealed [2-6]. It is a well known fact that cotton fibers can be considerably modified in terms of crystallinity, orientation of crystallites, and tensile and mechanical properties by subjecting them to swelling and stretching treatment with selected reagents [7]. The orientation of crystallites in cotton fiber is slightly improved upon slack swelling; however, substantial improvements occur in the degree , of crystallite orientation, static Young's modulus, and average single fiber tenacity, when stretch is applied . to cotton fibers after slack mercerization and the swollen-stretched fibers are subsequently washed in water and air dried. These improvements do not entirely result from changes in crystallinity and orientation. Mercerization, both slack and with tension, increases the strength uniformity along the fiber length. These may be attributed to the reduction of structural imperfections or weak links in cotton during the combind swelling and stretching process [I]. Mercerization in yarn or fabric form causes some difficulties in terms of evenness of treatments [8]. Particularly, uniformity of fiber strain within those structures cannot be achieved when the process is performed under tension. This non-uniformity is attributed to the fiber arrangements in those structures. Stretch mercerization in roving form, which was proven to be effective in Part I of this study, was adopted to improve the uniformity of fiber strain [8]. The primary advantage of stretch mercerization in roving form is to achieve the uniform stretching of individual fibers compared with yarn or fabric mercerization. We expect that if fibers are mercerized and stretched in roving form then they will undergo a more uniform stretching compared to those in a twisted configuration. Fiber arrangement in rovings is almost parallel even though there exists a small amount of twist. The stretch...

In this investigation three techniques were developed by which cotton fibers in roving form were mercerized and stretched to their original length and then neutralized in the stretched configuration. The effectiveness of the three stretching systems was evaluated by testing the processed fibers and yams. The mechanical properties of the yarns made from stretch mercerized rovings were compared with those of yarns made of untreated fibers and slack mercerized fibers. Their properties were also compared '