GB2098244A - Fluid nozzle for the manufacture of textured yarns - Google Patents

Abstract

A fluid nozzle (7) for manufacturing textured yarns from filament bundles comprises a nozzle body (14), a needle (15) inserted into and secured in the body, and a yarn zone of disturbance (Z) formed within the nozzle body. A yarn passing hole (23, 36) is formed through the centre of the needle (15) and a yarn passing hole (18) communicating with the yarn passing hole of the needle is formed in the nozzle body. A fluid supply hole (21) feeds into an annular groove (31) formed between the periphery of the needle and the inner face of the nozzle body, and one or more O-rings (34) are fitted between the needle (15) and the nozzle body (14) to prevent leakage of the fluid to the outside. <IMAGE>

Description

SPECIFICATION Fluid nozzle for the manufacture of textured yarns The present invention relates to apparatus for the manufacture of textured yarns and, more specifically, relates to a fluid nozzle suitable for generating a fluid jet, e.g. an air jet, to be used for manufacturing textured yarns.

Spun filamentary yarns are ordinarily smooth and unattractive in terms of touch and feel. For example, since spun nylon filaments have a circular cross-section and are very slippery, they cannot be put into practical use without using a finishing process, except for special uses.

Accordingly, various methods have been adopted in which permanent loops, swirls or entanglements are imparted to filamentary yarns to give them flexibility or bulkiness not possessed by as-spun filamentary yarns.

For example, irregular entanglements or loops are given to filaments by utilising the turbulent effect of an air jet to render them bulky.

More specifically, a filament bundle is exposed to the turbulent flow of an air jet stream to separate monofilaments from one another and move them violently in a zone of disturbance, the filaments are taken out from the zone in such a manner that no tension is imposed on the filaments, and at the moment when the filaments are taken out from the zone, loops, swirls, coils or entanglements are irregularly given to the filaments as the result of a slackening of the filaments, whereby a bulky textured yarn is produced.

In this method, using an air jet, a large quantity of air has to be used, and the method is economically disadvantageous, especially when fine-denier yarns are processed.

It is an object of the present invention to provide an economical fluid nozzle in which leakage of the fluid towards the yarn introduction side of the nozzle can be prevented.

In accordance with the invention there is provided a fluid nozzle for the manufacture of textured yarns, which comprises a nozzle body having a yarn passing hole and a fluid supply hole, and a needle having a yarn passing hole formed axially centrally therethrough, said needle being slidably inserted sealingly into a generally cylindrical recess in the nozzle body so that a zone of disturbance for the yarn is formed between an inner face of the nozzle body and an outer face of the needle.

Preferably, an O-ring seal is provided in the periphery of the needle to effect a fluid seal between the needle and the nozzle body.

Leakage of the fluid to the yarn introduction side of the nozzle is thus prevented and all the fluid supplied to the nozzle is fed to the zone of disturbance. Accordingly, the utilisation efficiency of the pressurised fluid is increased, resulting in a saving of electrical power. If fluid supply tubes for a plurality of spindles are connected to a main fluid pipe extending to each of the spindles, then the same quantity of fluid acting on the yarn is supplied to the nozzle of each spindle and there is no variation in the quantity of the fluid supplied to the respective spindles. Therefore, the quality is uniform in the textured yarns produced from the respective spindles and there is no variation in the yarn quantity from spindle to spindle.

The present invention will now be described in detail with reference to the embodiments illustrated in the accompanying drawings, in which: Fig. 1 is a schematic diagram illustrating the structure of one embodiment of apparatus for the manufacture of textured yarns; Fig. 2 is a sectional side view showing one embodiment of nozzle in accordance with the present invention; and, Fig. 3 is a sectional side view showing another embodiment of nozzle in accordance with the present invention.

Referring first to Fig. 1, this shows an apparatus for the manufacture of textured yarns in which a filament bundle Y1 taken out from a yarn supply source 2 supported on a creel stand 1 is moved upwards and is positively advanced by feed rollers 3 and 4, after which the filament bundle Y1 is then moved downwards and introduced into a fluid nozzle 7 arranged in a nozzle box 5. If desired, the filament bundle Y1 may be passed through a water-applying device 6 for wetting the filament bundle before the filament bundle is introduced into the nozzle 7.

The yarn coming from the nozzle 7 is withdrawn under no tension by a feed roller device 10, fed to a setting heater 1 1, thermally set, guided to a winding device 12 and wound on a package 13.

The number of filament bundles introduced into the nozzle 7 is not particularly critical, and one filament bundle or two or more filament bundles may be supplied as desired to the nozzle of the present invention.

One embodiment of fluid nozzle in accordance with the present invention is illustrated in Fig. 2.

The nozzle 7 comprises a nozzle body 14 and a needle 1 5 inserted into and secured in the body 14. The nozzle body 1 4 has a cylindrical hole 1 6 for insertion of the needle 15, a frusto-conical hole 17 at the top, i.e. inner, end of the hole 1 6 in which the cross-sectional area gradually decreases in the direction of advance of the yarn, and a yarn passing hole 1 8 communicating with the frusto-conical hole 1 7 and issuing to the outside. This yarn passing hole 1 8 comprises a cylindrical portion 19 and an expanding portion 20 having a cross-sectional area which increases in the direction of advance of the yarn.

Around a region of the internal circumferential face of the nozzle body 14 there is formed an annular groove 22. A pressurised fluid supply hole 21 is formed radially through the nozzle body so that the hole 21 issues into the groove 22 outwardly of the peripheral face of the needle.

The needle 1 5 has a cylindrical section and a yarn passing hole 23 is formed axially through the centre of the needle 1 5 to pierce through the needle.

The needle 1 5 comprises a small-diameter portion 24, a large-diameter portion 25 and a flange portion 26, which are formed integrally. A tapered face 27 is formed at the top, i.e. inner, end of the needle 15 around its margin. The angle of inclination of the tapered face 27 is the same as the angle of inclination of an opposing tapering face 28 of the nozzle body 1 4 which defines the frusto-conical hole 17, so that a parallel-sided channel S is formed between the sloping body face 28 and the tapered face 27 of the needle.

This channel S communicates with an annular chamber 29 formed between the small-diameter portion 24 of the needle and the internal circumferential face of the nozzle body.

An annular groove 30 is formed around the needle within the large-diameter portion 25, and a fluid chamber 31 is thereby defined by the needle groove 30 and the overlying groove 22 in the nozzle body. A pressurised fluid is introduced into the chamber 31 by way of the fluid supply hole 21.

The fluid chamber 31 is in communication with the annular chamber 29 through a communicating hole 32 formed through a radial flange portion of the needle. The communicating hole 32 may be formed at just one position or at two or more positions around the circumference. When the hole 32 is formed at just one position, the pressurised fluid introduced into the annular chamber 29 forms a spiral stream flowing forwards while swirling around the small-diameter portion of the needle and acts to rotate the yarn.

The needle 1 5 is slidable along the inner circumferential face 1 4a of the nozzle body 14, and the length of the zone of disturbance Z defined between the forward end of the needle and the nozzle body is adjustable. An annular groove 33 is formed at one region in the outer surface of the large-diameter portion 25 of the needle 1 5 and an O-ring 34 of an elastic material, such as a nitrile rubber, is fitted in the groove 33 so that the fluid is prevented from leaking back to the outside through the narrow clearance between the peripheral face of the needle 1 5 and the inner circumferential face of the nozzle body 14.

Fig. 3 illustrates another embodiment of fluid nozzle of the present invention, and in Fig. 3 the same elements as those in Fig. 2 are indicated by the same reference numerals respectively. In this embodiment, annular grooves 42 and 43 in which O-rings 40 and 41 are fitted are provided at two positions along the length of a needle 39 inserted in a body 38 of a nozzle 37, so that the needle 39 is sealed tightly relative to the inner circumference of the body 38 by the O-rings 40 and 41.

The configurations and characteristics of yarns manufactured by using the foregoing nozzles 7 and 37 depend upon the quality, quantity and speed of the fluid, which parameters are inherent to the apparatus, and upon the yarn speed and the kind of fibres of the yarn to be processed. In order to obtain an optimum bulkiness, it is necessary that the dimensions of the various elements of the apparatus should be taken into account. More specifically, the size of the inlet 35 of the nozzle and the size of the outlet 20 of the nozzle have a relation to the kind and fineness of the yarn to be processed. The inlet 35 should be of a size large enough to pass the yarn therethrough with minimum obstruction due to friction, and it is preferred that a guide composed of a hard material such as a ceramic material should be arranged at the inlet portion only.

In order to prevent backward flowing of the fluid from the zone of disturbance Z, the diameter of the forward end portion 36 of the yarn passing hole of the needle 1 5 or 39 is made smaller than that of the hole 23.

In order to produce an abrupt speed differential in the yarn effectively, a structure providing a high diffusion speed of the fluid is required, and for this purpose a striking or impingement plate opposed to the flow of the jetted fluid may be arranged in front of the outlet of the nozzle.

In the above-mentioned nozzle 7 or 37, the fluid supplied to the annular chamber 31 from the pressurised fluid supply hole 21 in the nozzle body is introduced into the chamber 29 through the communicating hole 32 in the needle 1 5 or 39 and is jetted into the sloping channel S formed between the needle 1 5 or 39 and the nozzle body 14 or 38 to exert a disturbing, swirling and separating action on the filament bundle. The filament bundle is discharged into the open air through the expanding portion 20 of the outlet together with the jet stream of the fluid, and an abrupt speed differential is produced among the filaments, causing irregular loops, swirls, coils and entanglements to be formed in the filaments, whereby high-bulk textured yarn is formed.

Claims (7)

1. A fluid nozzle for the manufacture of textured yarns, which comprises a nozzle body having a yarn passing hole and a fluid supply hole, and a needle having a yarn passing hole formed axially centrally therethrough, said needle being slidable inserted sealingly into a generally cylindrical recess in the nozzle body so that a zone of disturbance for the yarn is formed between an inner face of the nozzle body and an outer face of the needle.

2. A fluid nozzle as claimed in claim 1, in which an O-ring seal is provided in the periphery of the needle to effect a fluid seal between the needle and the nozzle body.

3. A fluid nozzle as claimed in claim 2, wherein a plurality of O-ring seals are fitted in the periphery of the needle.

4. A fluid nozzle as claimed in any preceding claim, wherein a frusto-conical hole having a cross-sectional area which decreases in the direction of advance of the yarn is formed in the nozzle body at the forward end of the generally cylindrical recess in the nozzle body and communicates with the yarn passing holes at least partially to define the zone of disturbance, and wherein pressurised fluid is supplied to said zone through an annular passage defined by the surface of the frusto-conical hole and a tapered surface formed at the forward end of the periphery of the needle.

5. A fluid nozzle as claimed in claim 4, wherein the angle of inclination of the tapered surface of the needle is the same as the angle of inclination of the surface of the frusto-conical hole.

6. A fluid nozzle as claimed in claim 4 or 5, which includes a first fluid chamber communicating with the fluid supply hole and defined by a circumferential groove in the nozzle body and a circumferential groove in the needle.

and a second chamber within the nozzle body communicating with the first fluid chamber through one or more communicating holes, said second chamber being in communication with said annular passage.

7. A fluid nozzle for the manufacture of textured yarns substantially as hereinbefore described with reference to Fig. 2 or Fig. 3 of the accompanying drawings.