GB586017A - Improvements in or relating to the stretch-breakage of artificial filaments - Google Patents

Abstract

<PICT:0586017/IV/1> <PICT:0586017/IV/2> <PICT:0586017/IV/3> A tow of continuous cold-drawable and/or cold-drawn artificial filaments, e.g. nylon filaments, is converted into a spinnable top without destroying the continuity of the tow or the substantial parallelism of the fibres by subjecting the plurality of filaments to stretching and breaking between pairs of rolls, the stretch being simultaneously applied in varying amounts to the individual filaments. Varying degrees of stretch are given to adjacent filaments, prior to breakage, by positioning one pair of rolls at an angle to the other pair, or by employing as the second pair rolls having frusto-conical surfaces. As shown in Fig. 1, the drawing rolls 10, 12 are set at an angle to the retaining rolls 6, 8. Rolls 6 and 10 are driven, the peripheral speed of 10 being greater than that of 6. The reach between the retaining and drawing rolls varies in length from end to end and varying amounts of stretch are therefore applied to adjacent filaments in the tow passing therebetween, some of which are broken. The top passes from the drawing rolls through a condenser 14 and condensing rolls 16, 18. Either the retaining rolls or drawing rolls may be set at right angles or at any other angle to the tow of filaments. In a modification, Fig. 6, two pairs of drawing rolls 44, 46 are employed to one pair of retaining rolls 40, 42. In Fig. 7, the drawing rolls 54, 56 have frusto-conical surfaces and their axes may be parallel to or set at another angle to the axes of the retaining rolls 50, 52. The non-uniformities in fibre lengths may be further accentuated by varying the relative speeds of the retaining and drawing rolls or by intermittently stopping the retaining rolls. The tow may be made up of undrawn, partially drawn or fully drawn filaments or a combination thereof and may comprise filaments of varying denier. The tow may be subjected to a preweakening treatment such as by partial fusion or partial solution at intermittently spaced points. A top is produced by the process from which yarn can readily be spun and in which the individual fibres have varying affinities for dyestuffs so that variagated shades may be obtained by dyeing in a single bath. The Specification as open to inspection under Sect. 91 comprises also the application of the process to other filaments, whether cold-drawable or not, such as viscose rayon or cellulose acetate rayon. This subject-matter does not appear in the Specification as accepted.