EP0010229A1 - Method and apparatus for texturising multifilament yarns - Google Patents

Abstract

A process for texturizing bundles of filaments of synthetic high molecular weight materials at high speed, wherein the filament bundle is passed through a feed nozzle and is then brought into contact with a hot gaseous medium which is undergoing a vortical motion and has acquired a vortex angle of from 10 DEG to 70 DEG as a result of passage through a vortex chamber, is then heated by the fluid medium in a downstream tubular chamber and is subsequently fed to an expansion stage to produce the crimp, and apparatus for carrying out this process.

Description

The present invention relates to a method for texturing bundles of threads and a device suitable therefor.

Basically, it is known that bundles of synthetic high molecular weight fibers can be curled and swirled by passing the bundles of threads through an inlet nozzle, then allowing them to meet with a hot flowing medium, heating them up to the plasticizing temperature through a tubular chamber and then into one Expansion zone for curling and possibly swirling conducts. A suitable device is described in DE-AS 20 06 022, for example, the expansion zone being in the form of a tube with longitudinal slots. It is also known that the hot flowing medium is fed through a centering body for the tubular chamber in the nozzle (cf. DE-AS 20 00 622). It is also known that the hot flowing medium is given a swirl (DE-OS 26 32 384).

A process has now been found for texturing bundles of threads from synthetic high-molecular substances at high texturing speeds, in which the bundles of threads are passed through an inlet nozzle together with a hot gaseous medium which is in a swirling motion ment, are heated in a subsequent tubular chamber by this medium and then guided to the crimp in an expansion stage, in which the hot, swirling medium is guided by a swirl angle of 10 ° 70 °, preferably 20 to 50 °, by a guide in the swirl device ° there.

The twist angle is defined as the angle between the tangent to a helix that results when twisting a previously straight surface line of a cylinder (or cone) and a parallel to the axis that intersects the tangent.

It is surprising that not only is a crimped and intermingled yarn obtained as expected, but that it also has a better crimp value than a textured yarn which has been produced analogously but without a twist with the specific twist angle. Another advantage arises from the fact that the process can be carried out at a somewhat lower temperature than can be used in a process without the specific swirl movement. Surprisingly, the yarn feed tension in front of the game inlet nozzle increases by a factor of 2 and even higher under the effect of the directed twist. Therefore, a roving with a small proportion of loops can be processed without any problems, which leads to malfunctions in a process without the specific swirl movement of the hot flowing medium.

The invention also relates to a device for texturing bundles of threads made of synthetic high-molecular substances consisting of an inlet nozzle for the bundle of threads, one or more feeds for a hot flowing medium to the bundle of threads, the feeds being designed in such a way that they twist the flowing medium - ben, a subsequent tubular cone, in which the bundle of threads is heated by the hot gaseous medium, and an expansion stage, in which in the feed for the hot flowing medium or the swirlers are designed so that the hot flowing medium has a twist angle of 10 up to 70 °, especially in a twist angle of 20 to 50 °.

A device as it is considered suitable is shown schematically in FIG. 1, FIGS. 2 to 3 show details.

The device consists of an inlet nozzle 1 (sometimes also called a thread insertion tube), a feed for the hot flowing medium 2 with a swirl sensor 3, a tubular chamber 4 (sometimes also called a thread guide channel) and an expansion stage 5, in FIG. 1 as a slot nozzle shown. An embodiment of the swirl sensor 3 is shown in FIG. The hot medium flowing through the channels is 6 - here formed as grooves - those directed at an angle of 10 to 70 °, in particular from 20 to 50 °, in this case represented by 45 ^{is 0,} are disposed to the movement direction of the yarn bundle. The channels 6 in the swirl sensor 3 can have, for example, square or rectangular cross sections; these embodiments can be produced particularly easily if they are milled as grooves in the swirl body which also serves as a centering body, the grooves then forming channels with the outer jacket 7 of the nozzle. The swirling at the desired angle can, however, also take place through channels 11 with a round or oval cross section, as are shown schematically in FIG. 3, for example. But you can also attach simple baffles, straight or curved. According to the invention, the swirl sensors are to be designed in such a way that the hot flowing medium has a swirl angle of 10 to 70 °, receives in particular from 20 to 50 °, practically flows at such an angle with respect to the imaginary axis of the inlet nozzle or the tubular chamber, since these are normally arranged coaxially and the flowing medium flows around this chamber.

The cross sections of the channels in the swirl sensor are variable within wide limits. However, it is advantageous if they are arranged symmetrically around the tubular chamber 4 and the free area is 1/4 to 3/4 of the annular area between the outer tube of the nozzle 7 and the tubular chamber 4. This circular ring area represents the free cross-sectional area around the yarn guide tube. The number of channels in the twister is expediently 4 to 12 pieces, preferably 6 to 10 pieces. Even if the number is not essential to the invention, there is an advantage with a number of 6 to 10 channels. With fewer channels, their effect wears off; with significantly more channels of correspondingly smaller dimensions, production becomes more expensive.

All common metals or alloys of sufficient temperature and corrosion resistance can be used as the manufacturing material for the nozzle and the air guide element. Stainless steels have proven particularly useful. Of course, other metals can also be used insofar as they meet the thermal-corrosive requirements.

The channels determining the swirl direction form an angle with respect to the longitudinal axis, the channels being able to lie on the jacket of a cylinder intended for the longitudinal axis of the tubular chamber or on a cone jacket, so that the channels incline towards this longitudinal axis or also from it lean away. In other words, the hot flowing media can meet on a smaller or a larger circle than that which corresponds to the average radius of the annulus between the outer jacket and the radius of the tubular chamber 4. The swirl sensor can be arranged in the immediate vicinity, for example at a distance which corresponds to the inner diameter of the tubular casing, from the point of union of the flowing medium and the running bundle of yarn, but it can also, if less effectively, be at a greater distance, for example the 3- up to 4 times the inner diameter of the jacket tube, be arranged from this union. The dimension of the texturing nozzles used are not changed by the device according to the invention. For example, devices known from DE-AS 20 06 022 or from DE-AS 23 31 045 with the dimensions specified there are very suitable. The ratio of the clear width of the inlet nozzle (the thread insertion tube) to the clear width of the tubular chamber (the thread guide tube) is expediently 1: 1.0 to 1: 4, advantageously 1: 1.4 to 1: 2.2. The diameter ratio and the dimensions themselves depend on the thickness of the thread bundles to be crimped. In general, it is expedient not to select the clear widths larger than necessary for the yarn transport in order to keep the consumption of the flowing medium low. Have proven themselves for the inlet nozzle, for example, with a diameter of 1,100 to 1,3 mm. Inlet nozzle and tubular chamber are primarily arranged coaxially at a distance of 0.1 to 3.0 times, preferably 0.8 to 1.4 times the outer diameter of the thread guide tube 4, in the specific case approximately at a distance of 0 , 3 to 1 mm, preferably from 0.4 to 0.5 mm. The tubular chamber is followed by an expansion zone which, when configured as a slot nozzle, has the same inside width as the tubular chamber. However, it can also suddenly or gradually change to a larger diameter. In the slot nozzle 4 to 18 slots have proven themselves with a slot width of 0.3 to 1.0 mm, in particular 0.4 to 0.5 mm. However, other devices can also be used which have the elenent inlet nozzle, annular gap, tubular chamber and expansion zone. The process conditions known for the respective nozzles also apply with regard to the relationship between the temperature of the heating medium and the type of thread bundle. However, it has been shown that, according to the invention, temperatures of the hot flowing medium which are generally 10 to 20 ° lower than those used without the specific swirling can be used. The process can generally be described with reference to FIG. 1 as follows: the bundle of threads 8 is fed into the texturing nozzle via the inlet nozzle 1, the flowing medium 9 is fed into the gap 10 between the inlet nozzle 1 and the tubular chamber via the feed 2 and the swirl device 3 4 led. The swirl sensor causes the flowing medium to swirl, which due to the shape of the swirl sensor leads to a swirl angle between 10 and 70 ° on the thread guide tube or on the thread bundle. In the drawn device, it is approximately 45 °. The range from 20 to 50 ° has proven to be particularly advantageous because the properties of the crimped yarn in terms of crimp value, tensile strength and elongation at break are in a particularly favorable range.

The further run of the thread bundle through the tubular chamber 4 and the expansion zone runs as usual.

In the present context, bundles of threads are understood to mean endless structures made of individual threads, the individual threads also being ribbons, flat threads or splicing fibers made of foils or foil strips, and furthermore the individual threads being round or profiled, for example trilopal cross sections can have. The titer of the individual threads can be, for example, 1 to 30 dtx, they are preferably 10 to 25 dtex. The number of individual threads in the thread bundles or yarns can be between 2 and a few thousand. The threads in the thread bundles can be partially stretched or totally stretched. It is also possible to use bundles of thread which have a certain pre-twist, for example up to 30 turns / m, in particular up to 25 turns / m, as a result of which they have better cohesion.

The thread bundles of linear or practically linear organic high molecular weight for the production of the thread are particularly customary linear synthetic high molecular weight polyamides with carbonamide groups recurring in the main chain, linear synthetic high molecular weight polyesters with recurring ester groups in the main chain, thread-forming olefin polymers, and cellulose derivatives such as cellulose derivatives. Suitable high-molecular compounds are in particular nylon-6, nylon-6.6, polyethylene terephthalate, linear polyethylene or isotactic polypropylene.

The gases used for this purpose are used as the flowing gaseous medium, for example nitrogen, carbon dioxide, water vapor and, in particular for economic reasons, air. The required temperatures of the flowing medium can be within wide ranges. A temperature range of 80 to 550 ° C has generally been found to be expedient, the most favorable conditions for the respective material from the melting or plasticizing temperatures of these materials, the speed of sound of the flowing medium at the respective temperature and the pressure used, the time during which the flowing medium acts on the thread bundle, the temperature at which the thread bundle is fed, and also of the Thickness of the individual threads, ie depend on the titer. Naturally one cannot use temperatures which lead to melting of the threads under the selected conditions, although the temperatures themselves can be above the melting or decomposition points of the thread-forming materials used, provided that the threads run at a correspondingly high speed (short dwell times ) are led through the treatment zone. The higher the throughput speed, the higher the temperature of the medium can be above the plasticization range or the melting or decomposition point of the thread-forming material used.

The plasticization ranges are, for example, for linear polyethylene at 80 to 90 ° C, for polypropylene at 80 to 120 ° C, for nylon-6 at 165 to 190 ° C, for nylon-6.6 at 120 to 240 ° C and for polyethylene terephthalate at 190 to 230 ° C.

The temperatures for the flowing medium are generally higher than the plasticizing temperatures, for nylon-6 e.g. When using air as the flowing medium, a temperature range of 175 to 380 ° C has been proven. For the other polymers, the lower limit of the preferred range is approximately 10 ° above the lower limit of the plasticization range and, depending on the residence time and titer, extends up to approximately 200 ° above the lower limit of the respective plasticization range.

The flowing medium is generally applied at a pressure of 2 to 15 bar, preferably 5 to 9 bar.

The texturing speed is 1200 to 3000 m / min. Speeds of 1800 to 2500 m / min are preferably used. High speeds have smaller dwell times times, these allow higher temperatures of the flowing medium.

The swirl sensor, which surrounds the tubular chamber (the thread guide rotor), represents the narrowest point of the free cross section of the medium feed. It is advisable to dimension this free cross section at the narrowest point in such a way that throughputs of 0.35 to 2.0 m ³ (normal conditions) per hour and mm ² . Under these conditions, there are particularly high withdrawal tensions at the supply organs, for example the stretch godets. The amount of hot flowing medium to be used also depends on the yarn titer, the desired crimp intensity and the chemical nature of the thread bundle.

example

An undrawn polyamide 6 roving with the titer 4200 f 67 dtex is drawn off from a bobbin and fed to the drawing device of a drawing texturing machine, with a drawing ratio of 1: 3.45 being set. The temperature of the inlet godet into the stretching field is 100 ° C and the temperature of the outlet godet of the stretching field is 150 ° C. The preheated and drawn thread is fed to a crimping device shown in FIG. 1 at a speed of 2000 m / min. Air of temperature 300 ° C. is supplied through the pipe socket 2 at a pressure of 5.3 bar. The air volume of 6.5 Nm ³ / h is now guided through the 8 air channels arranged in a circle, which are inclined counter-clockwise by 40 ° with respect to the axis of the texturing device. The free cross section of the annular space is 43 mm ² , the free area of the 8 air channels _{1 is} 4.4 mm ² .

The yarn inlet nozzle 1 has a clear width of 1.1 mm. The thread guide channel 4 has a clear width of 2.4 mm and an outer diameter of 3.0 and a total length of 127 mm. This results in a ratio of the inside width of inlet nozzle 1 to the inside width of thread guide channel 4 of 1: 2.2. Between the inlet nozzle 1 and the thread guide channel 4 there is an annular gap 10 of 0.4 mm due to the set air duralone set. At the end of the thread guide channel 4, the cylindrical slot nozzle, as described in DE-AS 20 06 022, is pushed on. The distance between the end of the thread guide channel 4 and the beginning of the slots in the slot nozzle 5 is 0.83 times the outer diameter of the thread guide channel. The expansion zone consists of a slot nozzle 5 with 12 slots and a slot width of 0.5 mm. The tension of the thread to be textured is 65 cN before the thread insertion channel. The yarn has a crimp of 12.6% (KWH).

Example 2

An undrawn folyamide 6 roving with the titer 4200 f 67 dtex is drawn off from a bobbin and fed to the drawing device of a drawing texturing machine, with a drawing ratio of 1: 3.45 being set. The temperature of the inlet godet into the stretching field is 100 ° C and the temperature of the outlet godet of the stretching field is 150 ° C. The preheated and drawn thread is fed to a crimping device shown in FIG. 1 at a speed of 2000 m / min. Air with a temperature of 350 ° C. and a pressure of 5.3 bar is fed through the pipe socket 2. The air volume of 6.5 Nm ³ / h is now passed through the 8 air channels arranged in a circle, which are inclined counterclockwise by 15 ° with respect to the axis of the texturing device and leave 1/3 of the free cross-sectional area around the tubular chamber 4. The yarn inlet nozzle 1 has a clear width of 1.1 mm. The thread guide channel 4 has a clear width of 2.4 mm and an outer diameter of 3.0 and a total length ven 127 gives you a ratio of the inside width of the inlet nozzle 1 to the inside width of the thread guide channel - before 1: 2.2. Between inlet nozzle 1 and thread guide channel - there is an annular gap 1C of 0.4 mm due to the set air flow. At the end of the thread guide channel 4, the cylindrical slot nozzle, as described in DE-AS 20 06 022, is pushed on. The distance between the end of the thread guide channel 4 and the beginning of the slots in the slot nozzle 5 is 0.83 times the outer diameter of the thread guide channel. The expansion zone consists of a slot nozzle 5 with 12 slots and a slot width of 0.5 mm. The tension of the thread to be textured is 45 cN in front of the thread insertion channel. The yarn has a crimp of 11.4% (KWH).

Example 3

In comparison to Example 1, an undrawn polyamide 6 roving with the titer 4200 f 67 dtex is drawn off a winding body and fed to the stretching device of a stretch texturing machine, with a stretch ratio of 1: 3.45 being set. The temperature of the inlet godet in the stretching field is 100 ° C and the temperature of the outlet godet in the stretching field is 150 ° C. The preheated and drawn thread is fed at a speed of 2000 m / min to a crimping device which corresponds to that used in Examples 1 and 2, but does not contain a twister 3. Air at a temperature of 390 ° C. is supplied through the pipe socket at a pressure of 5.3 bar. The air volume of 4.7 Nm ³ / h is led directly through the air gap between the yarn inlet nozzle 1 and the thread guide channel 4. The air flow before entering the air gap runs parallel to the thread guide channel, ie without any specific twist.

The Garmeinlaufdüse 1 has a clear width of 1.1 mm. The thread guide channel 4 has a clear width of 2.4 mm and an outer diameter of 3.0 and a total length of 127 mm. This results in a ratio of the inside width of inlet nozzle 1 to the inside width of fader guide channel 4 of 1: 2.2. Between the inlet nozzle 1 and the thread guide channel 4 there is an annular gap 10 of 0.3 mm due to the set air flow. At the end of the thread guide channel 4, the cylindrical slot nozzle, as described in DE-AS 20 06 022, is pushed on. The distance between the end of the thread guide channel 4 and the beginning of the slots in the slot nozzle 5 is 0.83 times the outer diameter of the thread guide channel. The expansion zone consists of a slot nozzle 5 with 12 slots and a slot width of 0.5 mm. The tension of the thread to be textured is 30 cH before the thread insertion channel. The thread is before the 30 yarn has a crimp of 10.5% (KWH).

If the air is fed to the pipe socket 2 at a temperature of only 300 ° C., the yarn has a crimp of 8.2% (KWH).

Sign.

Claims (4)

1. A method for texturing bundles of threads made of synthetic high-molecular substances with high texturing speed, in which the bundle of threads is passed through an inlet nozzle, meets a hot gaseous medium which is in a swirling motion, is heated in a subsequent tubular chamber by the flowing medium and is then heated to Ripple is supplied to an expansion stage, characterized in that the hot flowing medium in swirling motion is given a swirl angle of 10 to 70 °, preferably 20 to 50 °, by a guide in the swirl generator. 2. Device for texturing bundles of threads made of synthetic high-molecular substances - an inlet nozzle for the thread bundle, one or more feeds for a hot flowing medium to the thread bundle, these feeds being designed in such a way that they give the flowing hot medium a twist, - A subsequent tubular chamber in which the bundle of threads is heated by the hot flowing medium, and - an expansion stage,
characterized in that in the or the feeds for the hot flowing medium the swirl generator (s) are designed so that the hot flowing medium has a swirl angle of 10 to 70 °, in particular a swirl angle of 20 to 50 °. 3. The method according to claim 1, characterized in that the swirl is generated in the immediate vicinity of the union of hot flowing medium and bundle of threads. 4. The method according to claims 1 or 3, characterized in that the flowing medium at the free cross section of the narrowest point of the twister around the yarn guide tube in a pressure range of 2 to 15 bar at a texturing speed of 1500 to 3000 m / min, preferably from 1800 to 2500 m / min, a throughput of 0.35 to 2.0 m ³ (normal conditions) / h and mm ² , preferably from 0.4 to 1.0 m ³ (normal conditions) / h and mm ² .

Images