GB1368317A - Bulk yarn and process and device for obtaining this yarn - Google Patents

Abstract

1368317 Bulk yarns; fluid nozzles RHONEPOULENC-TEXTILE 21 Oct 1971 [22 Oct 1970 (2) 9 Dec 1970] 49005/71 Headings D1F and D1W A bulk yarn made of natural, artificial or synthetic textile material has interlaced filaments which are substantially free from loops and other visible convolutions not forming part of loops or convolutions in the yarn as a whole, and has alternating open and compact zones, the spacing between the open zones being 5-50 mm, the specific volume of the open zones being at least twice that of the compact zones and the open zones being substantially spindle-shaped. The filaments being randomly distributed within the open zones. The average length of the compact zones being less than that of the open zones. Some filaments may be broken in the open zones to give protruding filament ends. The yarn may be formed from two starting yarns of the same or different fibre materials, and may be produced as a core yarn. A process for producing such a yarn comprises feeding at least one yarn at at least 200 metres per minute, under substantially no tension and without rubbing, axially through a nozzle 1 comprising three successive coaxial cylindrical portions 4, 5, 7, of which the middle portion 5 is of a greater diameter than either of the other portions 4, 7, and introducing pressurised fluid into the portion 5 in the form of a stream passing through a conduit 6 at an acute angle to the direction of travel of the yarn through the portion 5. Two yarns may be fed to the nozzle, one being overfed relative to the other to produce a core yarn. In a preferred embodiment, the yarn is passed through an interlacing nozzle after leaving the above described nozzle. The yarn produced is taken-up on a ring and traveller spinning machine or a surface driven package winder. When two yarns are employed, one yarn is preferably fed at a controlled speed which may be intermittently varied. A nozzle most suitable for use in the process of the invention comprises three successive coaxial cylindrical portions 4, 5, 7 (see Fig. 4), of which the middle portion. 5 is of greater diameter than either of the other portions, a conduit 6 arranged at an acute angle to the direction of travel of the yarn through the middle portion and connected to the middle portion 5, the first upstream reduced diameter portion 4 including a tube 19 which is adjustable in position relative to the other portions, for example by means of a screw 20.