TWI774665B - Method and device for cooling a synthetic yarn - Google Patents

Abstract

The invention relates to a method and to a cooling device for cooling a synthetic yarn within a texturizing zone of a texturizing machine. To this end, a cooling liquid is introduced into a cooling groove of a cooling body, said cooling liquid being distributed in the groove base of the cooling groove. The heated yarn is guided in a contacting manner through the cooling groove. In order for an excess of cooling liquid to be avoided at the end of cooling, the cooling liquid, depending on a yarn count of the yarn, is supplied through a metering opening in the groove base of the cooling grove at a conveying rate in the range from 0.05 ml/min to 5 ml/min, wherein the conveying rate of cooling liquid is generated by a controllable metering means.

Description

Method and cooling device for cooling synthetic yarn

The present invention relates to a method for cooling synthetic yarns as described in the preamble of claim 1, and to a cooling device for carrying out the method as described in the preamble to claim 6.

For processing spun synthetic yarns, a method for crimping multifilament yarns has been used for decades, also known in the industry as so-called false-twist texturizing. For this purpose, partially oriented yarns that have been previously produced by a melt-spinning process are crimped in the texturizing zone of the weaving machine. In this case, a false twist is produced mechanically on the yarn, the reproduction of which is opposite to the running direction of the yarn. The yarn in this twisted state is heated to a temperature in the range of 200°C. The plastic state of the yarn material obtained here results in twists being pressed into the individual filaments of the yarn. To set this yarn structure, the yarn is then immediately cooled to a temperature of about 80°C. Thus, the crimp is retained in the yarn to achieve the desired processing. Cooling of the yarn here is preferably effected by air-cooled cooling rails guiding the yarn in contact on its surface. However, this type of cooling track basically has the disadvantage that a relatively long cooling section is required in order to achieve proper cooling of the yarn. Therefore, with regard to the cooling of the yarn with cooling liquid, several methods and devices are known from the prior art in order to be able to achieve the shortest possible cooling section.

A generic method and a generic device are known, for example, from European Patent No. EP 0 403 098 A2. With regard to the known methods and known devices for cooling synthetic yarns, the cooling body is provided with a cooling groove, the bottom of which has a plurality of depressed groove pockets. The cooling tank is coupled to the cooling liquid reservoir with capillaries whereby cooling liquid is continuously introduced into the cooling tank. The hot yarn is guided through the cooling slot in a contact manner and cooled with a cooling liquid. The yarn is then guided over a downstream cooling track.

With respect to the known method and known apparatus, the cooling body forms a relatively short cooling section in which the excess cooling liquid at the end of the cooling body is collected and sent back to the water tank. Considering that hundreds of weaving zones operate side-by-side in parallel in conventional weaving machines, the recovery of cooling liquid leads to significant additional complexity.

In order to minimize the excess of cooling liquid during cooling of the yarn, a method for cooling synthetic yarns in the weaving zone is known from World Patent No. WO 0138620 A1, wherein the cooling liquid is supplied to the yarn with a metering pump, wherein, The adjustment of the metering pump depends on the application of the monitored liquid on the yarn. The application of the liquid to the yarn was measured on a portion of the yarn with an electrical resistance after cooling. Although a relatively large excess of cooling liquid can indeed be avoided, the disadvantage is that a state of insufficient cooling of the yarn may occur due to insufficient cooling liquid. These states directly lead to deterioration of crimp uniformity.

At this point, the object of the present invention is to provide a generic method with A generic cooling device for cooling synthetic yarns in the weaving zone of a weaving machine, by means of the method and the device, respectively, a uniform cooling of the yarn can be effected without any substantial excess of cooling liquid.

Another object of the present invention is to improve a generic method and a generic cooling device for cooling synthetic yarns in this way, in particular being able to cool numerous yarns in parallel under the same conditions.

This object is achieved by a method for cooling synthetic yarns, as described in the preamble of claim 1, and a cooling device for carrying out the method, as described in the preamble of claim 6.

Advantageous refinements of the invention are defined by the features and combinations of features of the respective appendices.

The invention is based on the concept that there must be a specific correlation between the quantity of cooling liquid and the quality of the yarn in order to obtain the desired cooling effect on the one hand and to minimize any excess of cooling liquid at the end of cooling on the other hand. Here, it is ensured that the cooling liquid is supplied to the yarn in a reliable manner. The method of the invention thus provides for supplying the cooling liquid to the tank of the cooling tank through a metering opening at a delivery rate between 0.05 ml/min and 5 ml/min depending on the yarn count of the yarn bottom. Depending on the yarn count of the yarn, the desired cooling can thus be achieved without any relatively large excess of cooling liquid after cooling.

Due to the relatively strong evaporation of the cooling liquid after the first contact of the cooling liquid with the hot yarn, the wetting of the yarn to be cooled takes place in the cooling section on the groove bottom of the cooling groove. For this purpose, according to an advantageous development of the invention, the yarn is guided over a section with a length of between 100 mm and 300 mm cooling section in between. A uniform wetting and cooling of the yarn is thus possible.

Here is a variant of the method for distributing the cooling liquid within the cooling tank over a plurality of successive pockets in the bottom of the pocket, wherein the yarn is guided in contact over a plurality of pockets arranged between the pockets web, which has proven to be particularly successful. Thus, even the cooling effect on the yarn can be enhanced so that relatively short cooling sections can be implemented.

In order to maintain a given yarn guide and at the same time evenly contact the yarn of the cooling tank in the weaving zone, with regard to the method variant of guiding the yarn through a plurality of yarn guides arranged upstream and downstream of the cooling tank, It is particularly advantageous that the cooling groove has an arcuate groove bottom between the yarn guides in the yarn running direction. In particular, the angle at which the yarn enters the cooling groove and the angle at which it is guided away from the cooling groove can thus be set in a particularly precise and reproducible manner. Due to the yarn guide, no individual adaptations are required in the machine or in the weaving area.

In order to make the environment as vapor-free as possible, the improvement of the method of the invention with regard to the collection and suction of the vapor generated by the wetting of the yarn in the cooling bath is provided. The collection and discharge of vapour is particularly advantageous in view of the processing of numerous yarns side by side in a weaving machine.

A vacuum connector of the suction device can be assembled in a particularly advantageous manner at the low point of the cooling tank in the outlet region, so that, in addition to the vapour, unconsumed residues of the cooling liquid are also discharged.

In order to carry out the method, the cooling device of the invention has metering means for supplying cooling liquid, wherein the metering means has metering means for producing a cooling liquid delivery rate between 0.05 ml/min and 5 ml/min. This type of dosing means is best realized with a metering pump, which produces a continuous Uniform cooling liquid delivery flow and supply to the cooling tank.

The application of the cooling liquid to the yarns in the cooling tank that pass over the specific cooling section is carried out. For this purpose, the cooling grooves on the cooling body are constructed with a length between 100 mm and 300 mm.

In order to enhance the cooling effect, the cooling grooves provided in the groove bottom have a plurality of recessed groove pockets each used to guide the webs in the groove bottom to separate from each other.

Here, the guide webs between the pockets on the bottom of the cooling tank can be constructed with the same size web width and/or with different size web widths in order to carry out the threading of the yarn in the cooling tank. Yarn guidance and wetting.

In order to guide the yarn in a reproducible manner, a particularly advantageous refinement of the device according to the invention relates to a uniform contact in the bottom of the cooling groove, with at least one yarn guide arranged upstream of the cooling groove and one yarn guide located at the bottom of the cooling groove. Downstream, and with respect to the cooling groove, there is a groove bottom that is arcuate in the direction of yarn travel.

In order to collect and discharge the vapour, a modification of the device according to the invention is provided with regard to the cooling body being equipped with suction means on the cooling tank. The suction means are preferably configured to discharge from the cooling tank, in addition to vapour, fluid residues of the cooling fluid that may form in the outlet region. The environmental stress of the weaving machine can thus be avoided.

The method of the present invention for cooling synthetic yarns in the weaving zone of a weaving machine will be explained in more detail below using several exemplary embodiments of the device of the present invention with reference to the accompanying drawings.

1.1: The first transfer unit

1.2: Second transfer unit

2: feeding packaging

3: Yarn

4: Feeding packaging location

5: Heating device

6: Cooling device

7: False twisting equipment

8: Inlet channel yarn guide

9: Export yarn guide

10: Long cooling body

11: Cooling tank

12: Metering opening/nozzle opening

12.1: Metering catheter

13: Metrology Facilities

14: Metering means/dosing means

15: Motor

16: Controller

17: Arc groove bottom

18: Depressed Slot Bag

19: Guide the web

20: Container

21: Suction facility

22: Vacuum source

23: Suction cannula

24: Yarn inlet channel

25: Yarn outlet channel

26: Supply line

L: segment length

R: radius

In the drawings: FIG. 1 schematically shows a weaving section of a weaving machine with an integrated cooling device according to the invention for cooling the yarn; FIG. 2 schematically shows an exemplary embodiment of the cooling device according to the invention for cooling the yarn in FIG. 1 3 is a schematic diagram showing a cross-sectional view of the exemplary embodiment of FIG. 2; FIG. 4 is a schematic diagram showing a cross-sectional view of another exemplary embodiment of the cooling device of the present invention; A cross-sectional view of an exemplary embodiment.

Figure 1 schematically shows a section of a weaving machine, in particular the weaving zone. For this purpose, the weaving machine has a supply package position 4 in which a supply package 2 of yarn 3 is held. Yarn 3 was previously produced as partially oriented yarn (POY) by melt spinning. The first transfer unit 1 . 1 is assigned to the supply packaging position 4 . In this exemplary embodiment, the transfer unit 1.1 is formed by a godet unit with a plurality of cladding materials. The first transfer unit 1.1 forms a yarn run-in into a so-called weaving zone extending up to the second transfer unit 1.2. The second conveying unit 1.2 is likewise formed by a plurality of guide roller units with covering material. The guide roller units of the transfer units 1.1 and 1.2 are here as examples. In principle, in the case of guiding the yarn with the gap between the driven shaft and the contact roller and/or the contact belt, it is also possible to use a so-called nip transfer unit for guiding the yarn.

The heating device 5, the cooling device 6 and the false twisting device 7 are in the yarn The running direction is set in the weaving zone extending between the transfer units 1.1 and 1.2. The cooling device 6 is formed by the device of the invention and is shown in detail in FIGS. 2 and 3 .

An exemplary embodiment of the cooling device 6 according to the invention shown in FIGS. 2 and 3 is schematically shown in a longitudinal section in FIG. 2 and in a cross-section in FIG. 3 . As long as no explicit reference is made to either of these figures, the following description applies to both figures.

An exemplary embodiment of the cooling device 6 of the present invention has an elongated cooling body 10 . The cooling groove 11 extends on the upper surface of the cooling body 10 . The cooling groove 11 extends as far as the end face of the cooling body 10 , wherein the inlet channel thread guide 8 is arranged in the thread inlet channel 24 and the outlet thread guide 9 of the cooling groove 11 is arranged on the thread outlet 25 . The cooling groove 11 has an arcuate groove bottom 17, the curvature of which is represented by a radius R. The cooling section extending between the yarn inlet channel 24 , the yarn outlet channel 25 on the groove bottom 17 is designated by the section length L in FIG. 2 .

The metering opening 12 in the bottom 17 of the cooling tank 11 opens in the region of the yarn inlet channel 24 . The metering opening 12 is connected to the metering facility 13 by means of a metering conduit 12 . 1 and a supply line 26 . In this exemplary embodiment, the metering facility 13 has a metering member 14 connected to the container 20 . The cooling liquid is kept in the container 20 . The dosing means 14 are preferably constructed as a metering pump and driven by a motor 15 . The motor 15 is controlled by a controller 16 connected to a machine control unit (not shown here).

The groove bottom 17 in the part of the cooling groove 11 extending between the metering opening 12 and the yarn outlet channel 25 has a plurality of recessed grooves separated from each other by a plurality of guide webs 19 in the groove bottom 17 Bag 18.

It can be seen in particular from the illustration in FIG. 3 that the groove pockets 18 of the groove bottom 17 A depression is formed that can form a buildup of cooling liquid. The yarns 3 are guided in contact on the surface of the guiding web 19 .

As can be seen from the representations in FIGS. 2 and 3 , the suction device 21 is arranged above the cooling tank 11 . The suction device 21 has a suction sleeve 23 extending over the entire length and width of the cooling tank 11 on the cooling body 10 . The suction sleeve 23 is connected to the vacuum source 22 whereby the vapour generated by the cooling liquid as the yarn cools can be collected and discharged. A vacuum source 22 , which can be constructed as a blower, can advantageously operate a plurality of adjacent suction sleeves 23 .

At this point it should be made clear that this is an exemplary embodiment of the structure of the cooling device of the present invention. Therefore, suction means 21 can also be provided below the cooling tank in order to be able to additionally collect and discharge especially liquid residues at the yarn outlet.

From the illustration in FIG. 1 it can be seen that, for weaving the yarn with the false twisting device 7 , a twist is mechanically produced in the yarn, whereby the filaments of the yarn 3 are twisted. This twist is rewound against the direction of yarn travel and is generally stopped in the inlet channel of the weaving zone by so-called twist stops. Thus, the twisted yarn 3 in the heating device 5 is heated to a temperature of about 200°C. In order to cool the hot yarn in order to set the crimp, the yarn 3 is fed to the cooling device 6 with an inlet channel yarn guide 8 . In order to cool the twisted yarn, the metering member 13 generates a cooling liquid with a predetermined delivery rate, which is continuously introduced into the cooling tank 11 by means of the nozzle opening 12 . Here the delivery rate is set between 0.05 ml/min and 5 ml/min thereby establishing on the one hand a proper cooling of the yarn, and on the other hand, establishing that the yarn leaves the cooling tank 11 without a substantial amount of excess cooling liquid . By means of the twisted state of the yarn 3, the absorption of the cooling liquid is prevented (take-up), such that, depending on the yarn count, the cooling grooves are formed with specific section lengths between 100 mm and 300 mm.

In tests using polyester yarn with a yarn count of 300den, the yarn was able to cool properly within a cooling zone of 225 mm. Water is used as cooling liquid, to which, depending on the requirements, a small amount of oil, eg 1%, can be added to the water. The amount of cooling liquid is about 4 ml/min.

It has been determined that twisted yarns can be cooled more efficiently with an amount of cooling liquid between 5 and 15% of the weight of the yarn. Thus, liquid residues at the end of the cooling program can be minimized. Therefore, the method of the invention and the device of the invention are particularly outstanding because of the proper cooling of the yarn with a minimum of cooling liquid during the weaving process. No complicated liquid residue collection and preparation is required.

In addition, the yarn guides 8 and 9 used on the yarn inlet channel 24 of the cooling device 6 and on the yarn outlet channel 25 make it possible to pre-set the yarn guiding positions so that reproducible and identical constructions can be constructed in parallel processing positions. Yarn guide. Thanks to them, complicated setting operations in the weaving machine and in the weaving area can be dispensed with.

In the exemplary embodiment illustrated in FIG. 2 , the groove bottom 17 of the cooling groove 11 is configured in the cooling body 10 to have uniform groove pockets 18 such that the guide webs 19 between the groove pockets are each of the same size web width. In principle, however, it is also possible for the web width of the guide web 19 in the groove bottom 17 to be constructed in different lengths. For this purpose, Figure 4 illustrates an exemplary embodiment of the cooling device of the invention constructed with guiding webs 19 of different web widths. The exemplary embodiment of FIG. 4 itself differs in other respects from the exemplary embodiment of FIG. 2 The specific embodiment itself is the same, wherein the suction device 21 and the metering device 13 are not shown here. In the exemplary embodiment of FIG. 4 itself, the guide web 19 in the region of the outlet channel is constructed to be substantially wider than the rest of the area of the cooling tank 11 . The supply of cooling liquid to the yarn can be enhanced by a groove pocket 18 on the groove bottom 17 of the cooling groove 11 , whereby relatively short cooling sections and thus relatively short cooling grooves 11 can be implemented on the cooling body 10 . However, it is also possible to construct the cooling tank 11 without tank pockets.

FIG. 5 illustrates an exemplary embodiment of the cooling device of the present invention without the cooling tank 11 of the tank bottom 17 without the tank pocket 18 . The illustration of the suction device 21 and the metering device 13 is also omitted here. In this case, the yarn 3 is guided on the groove bottom 17 of the cooling groove 11 in an interrupted contact manner. Here, the cooling liquid introduced into the cooling tank 11 by means of the metering opening 12 is evenly distributed on the tank wall of the cooling tank 11, evaporated to the yarn outlet channel 25 or absorbed and carried away by the yarn.

In the exemplary embodiment of the device according to the invention shown in FIG. 5 , the metering duct 12 . 1 opens into the cooling tank 11 at an inclination to the running direction of the yarn. The conveying flow of the cooling liquid is thus already aligned with the yarn running direction, which contributes to the distribution in the cooling groove 11 .

1.1: The first transfer unit

1.2: Second transfer unit

2: feeding packaging

3: Yarn

4: Feeding packaging location

5: Heating device

6: Cooling device

7: False twisting equipment

8: Inlet channel yarn guide

9: Export yarn guide

10: Long cooling body

11: Cooling tank

13: Metrology Facilities

21: Suction facility

Claims (11)

A method for cooling synthetic yarns in a weaving zone of a weaving machine, the method comprising: directing a cooling liquid into a cooling tank of a cooling body, the method comprising: distributing the cooling liquid in the cooling tank groove bottom, and the method comprising: guiding the hot yarn through the cooling groove in a contact manner, characterized in that, depending on the yarn count of the yarn, between 0.05 ml/min and 5 ml/min At a delivery rate, the cooling liquid is supplied through a metering opening into the tank bottom of the cooling tank. The method of claim 1 wherein: the yarn in a cooling section on the bottom of the cooling tank is guided by a section length between 100 mm and 300 mm. 2. The method of claim 1 or 2, wherein: the cooling liquid is distributed within the cooling tank across a plurality of successive pockets in the tank bottom, wherein the yarn is guided in a contact manner over the assembled A plurality of webs between the grooved pockets. The method of claim 1, wherein: the yarn is guided through a plurality of yarn guides disposed upstream and downstream of the cooling slot, wherein the cooling slot has a direction of travel of the yarn between the yarn guides An arc-shaped groove bottom. 2. The method of claim 1 wherein: the yarn is wetted, and vapours generated by the wetted yarn are collected and sucked in the cooling bath. A cooling device for carrying out the method of any one of claims 1 to 5, having a cooling body for guiding an elongated cooling groove of the yarn, wherein the cooling groove is used in the groove A metering opening in the bottom is connected to a metering facility for supplying a cooling liquid, characterized in that the metering facility has a controllable metering member for producing a cooling between 0.05 ml/min and 5 ml/min Fluid delivery rate. The cooling device of claim 6, wherein: the cooling groove on the cooling body has a length between 100 mm and 300 mm. 7. The cooling device of claim 6 or 7, wherein: the cooling tank has in the tank bottom a plurality of recessed pockets each separated from each other by a guide web in the tank bottom. 8. The cooling device of claim 8, wherein: the guide webs between the slot pockets on the slot floor are constructed with the same size web width and/or with different size web widths. A cooling device as claimed in claim 6, Wherein: the at least one yarn guide is arranged upstream of the cooling slot, and one yarn guide is arranged downstream, and wherein the cooling slot has a slot bottom that is arc-shaped in the yarn running direction. The cooling device of claim 6, wherein: the cooling body is provided with a suction device on the cooling tank for collecting and discharging steam.

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