Fiber Configuration in Card Slivers with Different Types of Feed

Abstract

167 first integral desorption result in the formation of certain number of points of contact between polymer chains where adsorption of water vapor cannot take place. When the same samples are rehumidified and desorption is made effective through small steps of interval desorption, there is little possibility of the formation of the same number of points of contact as were formed during the previous desorption. That the changes in the accessibility of the polymers is not due to any breaking up of the crystalline regions is indicated by the fact that no changes in density were observed after integral or interval sorption and desorption. , Dear Stir :After the initial work of Morton and Summers [2] on the formation of hooks in fibers at carding, some studies were undertaken in this laboratory to investigate the mechanism of hook formation at the card.These have been reported in a separate communication [3]. Another aspect of the same problem is the relationship between the fiber configuration in the material fed at the card and that in the outcoming sliver. Such a study is of particular interest to workers who are engaged in investigating methods to prevent the formation of hooks totally or partially at the card. In the study now being reported, the laps fed to the card were specially prepared so as to have different degrees and types of fiber disorder, and the characteristics of the delivered sliver were examined.On a 37-in.-width SACM card, equipped with flexible wire fillet, a blow room lap (410 g/m) of an Indian cotton Digvijay (Baer Sorter mean length: 22.3 mm; fineness : 1.44 pg/cm ) was carded at 3.6 kg/hr. A part of the outcoming card sliver (A) was converted directly into sliver laps, and four such sliver laps were fed to the card again. These laps were of two types: (B) in which the trailing hooks of the parent card sliver were fed as trailing to the card and (C) in which the card sliver trailing hooks were fed as leading. The r maining parent card sliver was combed, extracting 1 c;{ noil. The combed sliver (G) was converted into s iver laps and fed to the card in three different ways: fi st ( D) the fibers were aligned to the direction of feed, secondly (E) they were perpendicular to the direction of feed, and finally (F) they were in a disordered state of orientation with reference to the direction of feed. The sliver laps were cut into several 36in.-long pieces and then fed transversely for the feed of type 1 E ) . The conditions for feed (F) were obtained by breaking up the sliver laps into small tufts, from which laps of one square yard were prepared by hand. In all cases the rate of feed was maintained at 3.6 kg,,'hr.The fluorescent-tracer-fiber technique 13] was used for counting hooks in the card sliver. The fiber extent of each tracer was also determined. This is a measure of the effective length of the fiber as it lies in the web and takes into account the shortening in length due to crimp, hooks, etc. The trailing and leading ends of fibers were designated with reference to the direction of ...

Studies on Hook Formation and Cylinder Loading on the Cotton Card

“…It has been shown earlier that the action of flats and the fiber configuration in the feed do not alter the incidence of hooking [ 19,20]. It was found in this laboratory that flat and lickerin speeds also have no effect on cylinder loading and fiber transfer characteristics.…”

Simulation on the fiber arrangement and distribution in the drafting zone

“…Before the drafting process, based on the sliver parameters, a sliver with the hook and straight fiber arrangement is generated using the model of Yang et al 32 and the nip line of the back roller is defined as the coordinate origin (0), as depicted in Figure 1. The fibers in the sliver were classified into five groups: [32][33][34][35][36] straight fiber, leading hooked fiber, trailing hooked fiber, hooked fiber at both ends and other hooked fiber. The heads of the fiber body sections are randomly distributed in a sliver with a given length based on uniform distribution.…”