Wrapping cotton yarn with a filament yarn may preclude the necessity for sizing prior to weaving and eliminate desizing and associated size-recovery systems. A study was made to define the proper ties of cotton/nylon and cotton/polyester spin-wrapped yarn of various filament sizes, weaving effi ciencies, and fabric applications. Core-wrapping is described, and the properties of the yarn produced are shown. Weaving efficiency results in terms of warp stops and lint shedding are presented.

A carding cleaner, developed at the Southern Regional Research Center for opening and cleaning cotton fiber, was adapted to clean and shorten the length of scoured wool fibers. Investigations were conducted with two types of wire clothing on both cylinders, a fine wire clothing having a high tooth density and a coarse wire clothing having a low tooth density, and two velocity differentials between cylinders. The effects of these conditions on removing trash and shortening the length of the fibers were examined using eight grades of scoured wool. The study showed the cylinders clothed with these wires significantly reduced the length of the wool fibers. It further indicated a low velocity differential between cylinders clothed with coarse wire cleaned the scoured wool as well as the fine wire cylinders and with an improved fiber length distribution.

Some observations were made of a card during developmental research. A reduction in air pressure above the lap feed to below zero, by means of an outside suction, affects detrimentally lickerin performance. Fiber separation in the card feed system is poorly accomplished and improvements will probably require a departure from the conventional design. A 3.6-in-diameter lickerin his about the same cleaning performance as a standard 9-in. lickerin. A 9-in.-diameter doffer cylinder with metallic closing per forms equally as well as a standard doffer, but the setting is more critical. An electro static force improves the alignment of unrestrained fibers, but practical application is difficult. Operation of a card at reduced speed shows normal performance and permits observation of the loading of the main cylinder.

Intensive investigations with a large-scale laboratory model of the SRRC carding cleaner (CC) and two grades of wool showed that the CC sufficiently shortened and cleaned the wool so it could be processed into yarn on the cotton system. A CC with a coarse wire and a low tooth density caused less fiber breakage and produced a better grade yarn compared to a fine wire with a high tooth density. For cotton/wool blends, open-end spun yarn has better quality than ring spun yarn. The study showed that to obtain uniform drawing sliver, roving, and yarn. more emphasis should be given to short than long fibers of the fiber length distribution in determining roll settings.

A carding cleaner that simultaneously cleans and shortens scoured wool fibers was investigated with various combinations of fine, medium and coarse metallic wires on the cylinders, four cylinder velocity differentials, and six spacings between cylinders. The optimum velocity differential and cylinder spacing for each wire was determined by measuring average fiber length, fiber length distribution, and percent of removed trash. Using the optimum factors for each wire, scoured wool was cleaned and short ened, blended with cotton, and processed into ring and open-end spun yarns using the conventional cotton processing system. Control lots of identical cotton/wool yarns were spun with wool produced using conventional wool processing methods. The results show it is possible to clean and shorten scoured wool with metallic wire cylinders, blend the wool with cotton fibers, and produce quality blended yams. Processing with the coarse wire produced the best fiber length distribution. The strength and uniformity of ring open-end cotton/wool yarns produced from carding cleaner prepared wool compared favorably with control yarns, but contained more neps and imperfections. The carding cleaner needs an improved doffing system to minimize nep formation.