CH644906A5 - METHOD AND DEVICE FOR PRODUCING A LOOP BLADE YARN. - Google Patents

Description

The invention relates to a method for producing a loop blown yarn from at least two continuous filament bundles, which with tradition - possibly with different delivery rates - are guided in a substantially vertical direction from top to bottom through a blowing nozzle operated with compressed air, in which they are formed together with the formation of individual capillary loops are mixed, whereupon the loop blow yarn is fed to a winding device which is arranged laterally offset with respect to the blow nozzle, and a device for carrying out this method.

A generic method is known for example from JA-OS 77 049 367 (AT: 15.10.75; OT: 20.4.77). A false twist textured continuous thread bundle and another multifilament yarn are mixed together in a blowing nozzle operated with compressed air, the capillaries of the false twist textured endless thread bundle being at least partially integrated in the form of small loops or loops. These small loops, which protrude from the surface of the loop blown yarn, generally lead to an improvement in the appearance and feel of the fabrics made from these yarns.

The technology of loop blown yarn production, also known as air texturing, nozzle texturing or air blasting texturing, has been continuously developed in recent years, both for texturing individual continuous filament bundles and for mixing and texturing two or more continuous filament bundles, by varying the feed speeds of the individual ones Interesting fancy yarns can also be produced for the blow nozzle. A good overview of the state of development of this technology is provided by the articles "Development of a nozzle for air texturing" by U. LIEBSCHER / K. STEGERER / G. HEBENSTREIT in Wiss.Z.d.Techn.Hochsch. Karl-Marx-Stadt 11 (1969), H.l, pp. 79-93, “The texturing of chemical threads in the air flow” by J. W. LÜNENSCHLOSS / J. G. HELLI in TEXTIL-PRAXIS 1969, August, pp. 515-520 and «Air-blasting texturing of polyester and other filament yarns» by G. BREHM in chemical fibers / textile industry, June 1978, pp. 552-558 and August 1978, p 706-708.

These articles show that, especially when air-jet texturing several partners with different shrinking or staining behavior, the uniformity of the loop formation (i.e. uniform loop size and loop density) and good mixing of the loops is important. Essential parameters for these peculiarities are on the one hand the blowing pressure, which must be relatively high at around 8-10 bar, on the other hand the thread speed, which must not be too high and generally reaches its maximum limit at 300-400 m / min. Air pressure and thread speeds must not be too high because there is a risk of mechanical damage, especially with fine-capillary yarns and yarns with low tensile strength. The result is fiber fly or fluff formation.

The invention has for its object to provide a method for producing a loop blown yarn from at least two continuous thread bundles, which allows intensive and uniform loop formation and intermixing of the loops with gentle treatment of the thread material, without relying on the common high air pressures or on the common low thread speeds to be limited.

This object is achieved according to the invention in a method of the type described in the introduction in that the continuous thread bundles are in a completely tension-free state as they pass the blow nozzle and in that the loop blow yarn blown out of the blow nozzle in the vertical direction in a freely swinging thread loop from bottom to top for winding reached.

It has been shown that the individual capillaries are only blown uniformly and intensively if they are completely free of tension during their passage through the nozzle and are carried out of the nozzle by the gas or air jet. A uniform and safely reproducible effect is only achieved when a freely looping thread loop is formed. The freely swinging thread loop can only form if the yarn partners to be blown pass the blow nozzle from top to bottom and reach the winding from bottom to top. The removal of the bundle of threads from the blowing nozzle through the blowing medium in the vertical direction from bottom to top or in the horizontal direction, as is known for example from DE-OS 1 410 415 or GB-PS 828 641, leads to a lack of control options with regard to a free Loop formation and, due to the resulting formation of a kink, just as little to form a freely swinging thread loop as pulling off a loop loop blown out of the blow nozzle.

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Blown yarns for winding in the horizontal direction or in the vertical direction from top to bottom, as is known from JA-PS 7 215 547 (AT: 1.7.67; OT: 9.5.72) or JA-OS 77 049 367. Finally, the loop blow yarn between the blowing nozzle and the take-up must not sag so much that the thread run has a more or less pronounced kink point, as is known from JA-OS 77 042 955.

Since it does not matter with which structural measures (nozzle geometry, arrangement of the blowing nozzle in relation to the winding device) the free-swinging thread loop is generated, these factors, which do not influence the running costs, can be matched to a specific yarn so precisely that at high working speeds Minimum air consumption can be set. Conventional textile yarns can be blown intensively and evenly at pressures of 3 bar or less with draws of 800 m / min or more. Mechanical damage to the yarn does not occur with this gentle treatment, and the textile data are not affected.

A further equalization of the texturing effect can be achieved if the continuous thread bundles fed to the blow nozzle are guided separately from one another until they enter the blow nozzle.

In order to achieve the build-up of the thread tension required for winding, conventional thread brakes can be used below the winding device. The loop blown yarn is preferably fed to the winding device via a device for building up the thread tension, which is passed from bottom to top.

The method according to the invention is suitable for the treatment of all common yarns in the fine, medium and coarse titer range (up to, for example, 3000 dtex for the decorative fabrics area), yarns of different materials, e.g. from polyesters, polyamides, polyurethanes, polyolefins, rayon, cellulose acetate or the like can be mixed with one another.

If more than two partners are blown together, it is advisable to supply the second, third etc. partner with the same tradition. It is essential to separate all partner threads up to the verbal point.

The invention also relates to a device for carrying out the method according to the invention.

This device has, in a manner known per se, delivery devices for the various continuous thread bundles,

a blowing nozzle with a substantially vertically running thread guide channel and a winding device arranged laterally offset from this blowing nozzle (JA-OS 77 042 955) and is characterized in that the

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Blowing nozzle has a thread guide channel that has a larger flow cross-section on the thread outlet side than on the thread inlet side, and that a thread deflecting element is arranged below the winding device, the thread guide surface of which lies on the thread outlet side vertically below the winding device.

The special blowing nozzle ensures a conveying effect, i.e. it blows the loop-blown yarn that forms from the thread guide channel vertically downwards. The deflecting member below the winding device also promotes the formation of the freely swinging thread loop.

In a preferred device, a thread separating pin is arranged in front of the blowing nozzle at a distance of approximately 5 to 20 mm. This separating pin means that the threads are only blown in the direction of the thread by the blowing air and leads to particularly even loops. Without a separating pin, pre-blowing occurs, which creates irregularly large loops. The distance of the separating pin from the blow nozzle largely depends on its diameter.

A further preferred embodiment provides that the delivery devices for the various continuous thread bundles are designed as conically stepped attachments of the friction roller of a winding device.

The invention is explained with reference to the drawing, in which a preferred embodiment is shown schematically.

From a bobbin 1, an endless thread bundle 2 is fed via a thread guide 3 to the conical shoulder 4 'of an attachment of a friction roller 5. The continuous thread bundle passes the paragraph 4 'twice via an overflow roller 6 and then runs to the blowing nozzle 7. From a second bobbin 8, a second endless thread bundle 9 runs via a thread guide 10 to the conical paragraph 4 "of the attachment 4 and arrives due to the smaller diameter thereof Paragraph 4 "compared to that of paragraph 4 ', at a lower speed to the blow nozzle 7 than the first continuous thread bundle 2. Both continuous thread bundles are separated by the thread separating pin 11 until immediately before their entry into the thread guide channel 7' of the blow nozzle 7, which via a line« L »with compressed air.

The loop blow yarn 12 () runs vertically upwards in a freely swinging thread loop S via a friction body 13 serving as a deflection element and tension building device, through a thread guide 14 for controlling the opening tension and thus also the size of the thread loop to the bobbin 15.

The position and shape of the freely swinging thread loop does not matter. It can also change during operation, cf. S '().

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1 sheet of drawings

Claims (6)

644906 PATENT CLAIMS 1. A process for producing a loop blown yarn from at least two continuous thread bundles, which are traditionally passed from top to bottom in a substantially vertical direction through a blowing nozzle operated with compressed air, in which they are mixed with one another while forming single capillary loops, whereupon the loop blown yarn a winding device which is arranged laterally offset with respect to the blowing nozzle is fed, characterized in that the continuous thread bundles are in a completely tension-free state as they pass the blowing nozzle and that the loop blow yarn blown out of the blowing nozzle in the vertical direction in a freely swinging thread loop from the bottom up for the winding reached. 2. The method according to claim 1, characterized in that the continuous filament bundles fed to the blow nozzle are guided separately from one another until they enter the blow nozzle. 3. The method according to claim 1 or 2, characterized in that the loop blow yarn is fed to the winding device via a tension building device. 4. Apparatus for carrying out the method according to one of claims 1 to 3, with delivery devices for the continuous thread bundle, a blowing nozzle with a substantially vertically running thread guide channel and one of these blowing nozzle arranged laterally offset winding device, characterized in that the blowing nozzle (7) has a thread guide channel (7 '), which has a larger flow cross-section on the thread exit side than on the thread entry side, and that a thread deflecting element (13) is arranged below the winding device (5; 16), the thread guide surface of which lies on the thread outlet side vertically below the winding device (5; 16) . 5. The device according to claim 4, characterized in that a thread separating pin (11) is arranged in front of the blowing nozzle (7) at a distance of 5 to 20 mm. 6. Device according to one of claims 4 or 5, characterized in that the delivery devices for the continuous thread bundles (2; 9) as conically stepped attachments (4 '; 4 ") of the friction roller (5) of a winding device (5" 16) are.