DE2256545A1 - METHOD OF MANUFACTURING A TEXTURED YARN - Google Patents

Description

The invention relates to improvements in the manufacture ' position of textured! Yarn. The invention particularly relates to the manufacture of a textured yarn through the false twist principle. Ealschzwirnen is one Technique used to create a texturing effect in yarns to achieve. A wrong twist is expedient achieved by first passing a running yarn through an area where it is brought to a temperature

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is heated above the transition temperature of the second order of the material from which the yarn is made, on which then the The yarn is allowed to cool and the cooled yarn is twisted will. The twist given to the cooled yarn runs along of the yarn in a direction opposite to the machine direction and back into the heating zone, so that the twisting ia yarn is fixed when it runs into the cooling zone and the temperature η την ·. * falls below the transition temperature of the second order. ■ ■

After the yarn has passed through the twister it is left untwisted again, with the final twist of the yarn, which has been fixed in the twisted state, a textured or puffed yarn is created.

With many textile fabrics it is necessary that a strong There is a lack of flexibility in the yarn, especially in the case of stretch textiles such as those used for women's stockings. the The bulkiness of the fabric made from the textured yarn depends mainly on the twist density of the yarn in the heating zone. With the expression "twist density" is the number of twists per unit of length meant in the yarn. The twist density depends on the nature and the physical properties of the feed Yarn, i.e. the chemical composition, the titer, the number of threads in the cross-section and the physical properties of the threads, and also according to the processing conditions used, namely yarn speed, twisting speed, Time and temperature of heating and cooling, frictional forces in the twisting device and the nature and amount of the lubricant on the surface of the yarn. It is difficult to make textured yarns that have a Develop bulkiness with constant thickness and which at the same time have low thermal shrinkage. The aim of the present invention is to provide one such yarn and a convenient method of making the same.

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A problem that occurs when texturing in large-scale. * Scale appearance-, lies ^d: ate the working conditions between a position slightly on one machine and another position are different. This easily results in a non-uniform yarn which creates streaks in the fabric made from this yarn, such as the rings that sometimes appear in women's stockings. It is believed that this non-uniformity is at least partly due to one: insufficient contact between the yarn and both the heater and the twist sleeve in the Texturierina-i »zone, which results in changes in the strength of the twist applied and also in the degree of twist fixation. It is an object of the invention to improve this non-uniformity. -. """

Various devices are known for applying a twist to a running yarn. With such a device the running yarn is guided around a part, which is arranged within a hollow spindle and rotates with it. This involves twisting the yarn applied as it passes through the spindle. With this technique is the amount of twist that is on a yarn running at a certain speed is applied can be limited, since it is only possible to have one Apply twist for each rotation of the spindle. Alternative techniques for applying a twist that include these No limitation, use the principle of friction, in which the yarn is twisted by contact with a rotating friction surface. The twisting devices, at which use the principle of friction, generally consist of rotating hollow surfaces with which the ' running yarn is brought into contact. In some such devices, the yarn passes through the cylindrical body through it, whereas with others the yarn attaches the body to the same

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Page enters and leaves and through a thread guide against the friction surface is held.

The present invention is concerned with making a textured yarn by the frictional false twist principle, as by this principle a stronger twist on the running yarn at a given rotation speed the twist sleeve can be applied and thus higher processing speeds can be used. It is also already known, a textured yarn by successive Stretching and texturing, using the same roller for pulling the yarn from both the te ^ - turing as well as from the stretching zone is used. However, this earlier method is the one used Graduated roll with the yarn running around the smaller diameter part after it passes through the texturing zone has passed through, so that the yarn tension is lower compared to the Lehnzoxxe, while the yarn through the texturing his unit runs through. It was found that this process results in a yarn having a non-uniform and relatively low bulk. It is finally also known that a yarn is partially drawn and then textured and fully drawn at the same time. This However, the method suffers from the disadvantage that the yarn speed and the tension of the yarn during texturing according to the desired draw ratio are fixed, and the method thus does not allow control of the yarn speed during texturing ensure that the necessary degree of bulk is achieved will. This method also requires a relatively high elongation in the texturing zone, whereby a Some of the twist is removed during the heating, resulting in a yarn with an undesirably low bulk Consequence. It has now been found that a yarn with a high bulk (which is reflected in the crimp stability

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expresses), can be obtained if you meet certain conditions adheres to.

Thus, according to the invention, there is a method of manufacture proposed a textured yarn in which a thermo- ■ plastic yarn successively stretched and by the Seibungsfalschswirnungsprinzip is textured, the yarn being continuously fed from the stretching zone to the texturing zone and the yarn then the texturing zone with a larger one Leaves speed as it enters the texturing zone.

It should be noted that the present invention only concerned with a process in which the speed increase in the texturing zone is relatively small and not of the same order of magnitude as the increase in speed generally used to stretch the yarn will. The particular increase in speed depends on the particular yarn, but it has not been found that any greater Increase than 10% should be used.

The inventive method can be applied to the 'production of a ■ Yarn made from any thermoplastic synthetic material used that, when twisted at a temperature higher than the second-order transition temperature and cooled in the twisted state, are fixed in "this twisted state will. Examples of particularly useful theimoplastic synthetic materials are nylon-6, nylon-6,6, polyacrylonitrile, and thermoplastic polyesters such as polyethylene terephthalate. -. "" -

In a preferred embodiment of the invention In the process, the unstretched yarn first runs from a feed point to a drawing roller, so that the yarn between the feed point and the draw roller is stretched. The yarn is then straight

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guided by the drawing roller through a heating zone, the preferably consists of a pen heater around which the yarn is wrapped, as this results in rapid heating and a even heat transfer between the: »yarn and the heater is ensured and higher working speeds can be used. It is believed that. the inventions Techniques are particularly suitable for procedures in which pen heaters are used because of the slight increase the gas velocity in the texturing zone Ensures good contact between the yarn and the pen heater, resulting in consistent heating and a, good There is contact between the yarn and the friction sleeve and a more constant swirl is obtained. Another The advantage of using a pin heater is that the extent to which the yarn is heated is easy can be changed by changing the distance the yarn runs around the heater. In addition, it has a pen heater the further advantage that it takes up considerably less space for the same heating than plate heaters that commonly used in procedures of this type. When the increase in speed in the texturing zone is too large, the high tension will pull out some of the bulkiness applied by the sleeve. However, if there is a decrease in yarn speed during texturing then the yarn becomes insufficient firmly against the friction sleeve (to apply an evasive twist) and also not against the heater (um to ensure adequate fixation of the twisted yarn). After the yarn has passed the heater, it is cooled to ensure that it is cold when it reaches the twister. It may be necessary To provide cooling means which direct cold air against the yarn, but in general it is more convenient if the The distance of the yarn between the heater and the twisting device is sufficient for the yarn to cool.

After cooling down, the yarn runs to the twisting device, which any of the known friction devices for applying a twist to a yarn. In particular such twisting sleeves are used, which are described in GB-PS 1 197 703. The use is very special a device is preferred, which is described in DT-OS 22 11 196.2. The twist applied to the yarn runs along the yarn back to the heater, so that the. yarn in the hot State is twisted. The hot, twisted yarn then cools down, as a result of which the yarn is fixed in the twisted state. In the The frictional false twisting technique has the twining device a rotating friction surface with which the yarn is brought into contact so that the rotation of the friction surface imparts a twist to the yarn. The yarn will run out the twisting device withdrawn in such a way that the withdrawal speed is greater than the speed with to which the yarn is fed to the twining device. In a preferred embodiment, the yarn is from the ZwirnungSVCrrichtung peeled off by the roll acting as a pulling roll is used for the expansion zone. In this particular technique, the role is graded so that the part around which the Yarn runs around at the end of the drawing zone; has a smaller diameter than the part around which the yarn after the texturing zone runs around so that the speed of the yarn increases between the two parts of the roll .. - This one Technology is preferred because the dual function of a single roller allows for a more compact device.

The preferred load by which the yarn speed in the The texturing zone should be increased depends on the nature, the denier and the amount of twist to be applied to the yarn away. It has been found, however, that for certain yarns, speed increase limits exist within

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-C-

which obtain the desired high curling resistance ^: is. It has been found that these limit values are generally within the elastic limits of the yarn, which is why in the process according to the invention there is usually no permanent elongation of the yarn as it passes through the texturing zone beyond the elongation caused by the texturing effect. This is evident from a comparison of the average denier of the yarn produced by the process according to the invention with the average denier of a yarn produced by a similar process in which there is no increase in speed in the texturing zone. There is essentially no difference in the two titers of the yarns. In some cases, however, the increase in speed can be such that a slight permanent stretching takes place, but this is generally very small. The preferred increase in yarn speed depends on the type of yarn in question. However, it has been found that a rate increase between 2 and 1C% is preferred. In particular, it has been found that an increase in gas velocity between 2 and 6% is suitable for making a textured polyamide yarn. An increase in speed of this magnitude during texturing essentially does not result in a greater permanent elongation than a similar process in which no such increase in speed occurs.

After the yarn has been withdrawn from the texturing unit it is fed to the winder. It has been found that the method according to the invention allows a To produce yarn with a high crimp stability, which is particularly important for yarns used in textiles are to be used where bulkiness and high elasticity are desired, such as in ladies'

Stockings. In addition, the yarns produced by the process according to the invention have a sufficiently low shrinkage so that a textile fabric made from the yarn practically does not change during the manufacture of the textile fabric. In addition, it has been found that the small increase in speed in the texturing zone results in an improvement in both the uniformity of the yarn obtained on one position of a machine and between the yarns obtained from different positions. It is believed that this is due to greater yarn stability. In some cases it is possible to see that the thread path is more stable during texturing than in similar processes where there is no speed increase during texturing. This improved stability also results in a smoother running process, as evidenced by the fact that thread breaks are less common when using the process of the invention.

The crimp stability of a yarn is a factor in the ability of a textured yarn to develop structural integrity during completion, and also to the ability of the yarn to retain bulk. The higher the crimp stability, the greater the degree of bulk and the more elastic the yarn. For the purposes of the description, crimp stability is determined by "making" a loop of the textured yarn and first attaching a 0.1 g / decitex weight to the yarn and immersing the weighted strand in water for 2 minutes of 20 ⁰ G is immersed * Then the strand length is measured. The weight is then replaced with a 0.002 g / decitex weight, and the length of the strand is then measured under similar conditions. The crimp stability is then expressed as the ratio of the length under a load of 0.002 g / decitex to the length under a load of 0.1 g / decitex

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as a percentage. In particular, by applying the erf ind'diigs genäse η process a yarn with a frizz, Stability of 35 to 50% and a shrinkage of veniger received as 5? o. The Ripple Stability Achieved depends of course on the denier of the yarn ·.

In a preferred embodiment of the method according to the invention, a twisting pretzel element is provided in the yarn path between the drawing roller and the heater. The term "twist un3breir.se le ment" refers to any system which prevents the twist from running back along a yarn. It may consist of a pin with which ^: The yarn is looped, although this is not preferred, because a sharp change in the direction of the yarn can cause 'fraying and damage to the yarn'. It is therefore preferred to use a system in which the direction of yarn travel is changed as slowly as possible than is consistent with achieving the necessary twist break. It has been found that a particularly useful twisting breaker consists of a series of yarn guides, which are primarily hollow or ceramic guides, among other things which the yarn runs, with the yarn path being forced to change by at least 75 °, when the yarn runs around every hell. It has been found that the use of a twisting brake element is useful because it prevents the twist applied by the twisting device from running back to the draw roller. If the yarn is twisted on the draw roller, a bad product can result because tension fluctuations can occur in the drawing zone, which can lead to uneven drawing and a variable product Roll up the roll so that adjacent strands are intertwined, thereby interrupting the process

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If the yarn moves on the surface of a roller which controls the yarn speed _Λ due to the torque generated by the texturing, then the surface of the roller is quickly damaged. The use of a twist brake element has an additional advantage when it is used together with a pin heater vri.rd, since, provided the brake element consists of a movable yarn guide, its position can be easily changed, whereby a simple. Procedure. to change the path of the yarn around the pin heater is created.

The essence of the method according to the invention is therefore ' a continuous stretching and texturing, whereby -the Yarn speed increases during texturing. It should be noted that this principle is based on a. procedure can be used in which the yarn is first stretched and textured at the same time and then textured further will. In this embodiment, the speed of the yarn is increased during the further texturing. In · This can be done in a similar manner by the method according to the invention Textured yarn produced as required. further textured will. Both methods seek to provide even greater uniformity in the finished bulked yarn achieve. ■

The yarn produced by the method according to the invention is a torque yarn, because 'it is only in one direction around its Axis has been twisted. However, if a torque-free Yarn is desired, then the inventive method can also be applied to two separate yarns running in parallel pass through the device and on the same Twist amounts, but applied in the opposite direction *

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whereupon the yarns to produce a torque-free composite yarn are combined.

The present invention also relates to a device for the successive stretching and texturing of a yarn, compare a leaning zone with a feeding device and a Pull-off device as well as a texturing zone with a feed. guide roller, a heater, a Reibuagstexturierujagsvqrrichtung and a pull-off device, wherein ..the feed roller also serves as a pull-off device for the texturing zone acts and is graded in such a way that the part with greater: Diameter acts as a pulling device.

The various modifications and designs of the 'The device according to the invention correspond to those already described Embodiments of the method.

The invention will now be explained in more detail with reference to FIG. 1 of the accompanying drawing. An undrawn yarn 1 becomes to feed roller 2 fed from where. .es to the stretching pin 3 and then to the pulling roller 5 The sealing roller 5 is graduated. The yarn runs from the drawing pin 3 to the part 6, which has a smaller diameter. The yarn then goes to the separator roll 4 and back to part The relative speeds of the feed roller 2 and the The draw roller 5 is set so that the yarn in the desired ..... Extent is stretched! Times the run around part 6 goes; the Yarn, to the heated pin 7 t which to a temperature above the transition temperature of the second order of the material which the yarn is made is heated. The yarn runs then to the yarn guide 8 and into the Seibungszwirnungsbächse 9 · The thread path between the heated pin 7 and the thread guide is sufficiently long that the thread is no longer sticky when

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-lyes runs through the guide S. With the twist bushing type shown the yarn runs through the can and becomes by Heiburig contact between the inner surface of the Twisted can and twine. The one applied to the yarn The twist runs back along the yarn to the heated pin 7i so that the yarn is twisted when it is hot and the twisting is fixed when the yarn cools down. The yarn runs from the twisting sleeve through another yarn guide 10 in part with a larger diameter of the hollow 5 - from part 11 that runs Yarn around the separator roll 4, back to part 11 of the Holle 5, back to the separator roll and through the yarn guide 8 and is then transferred onto the bobbin 12 with the aid of the hover 13 wound up. So this is the speed of the yarn when Passage through the texturing zone increases as it goes to this zone with the peripheral speed of the smaller part of the Roll 5 is fed and out of this zone at the peripheral speed the larger part is sucked off.

The invention is illustrated in more detail by the following examples, wherein the denier of the yarn relates to the denier after texturing.

example 1

22 decitex and 7 filament nylon 66 yarn was treated using the apparatus shown in FIG. The drawing roller 5 was driven so that the smaller diameter part 6 rotated at a peripheral speed of 685 m / min to draw the yarn at a ratio of 2.66. The Zwimungsbüchse 9 was rotated at a speed of about 21 500 U / min in rotation, and the heated pin 7 is to a temperature between 220 and 2J0 ⁰

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held. The roller 5 was graduated so that the peripheral speed of the larger part 11 was 4% larger than that of the smaller diameter part 6.

For comparison purposes, an identical sample of yarn was used in exactly edited the same way except that after the pass due to the texturing zone the yarn does not cover the part of the Roll 5 with a larger diameter (this is part 11) ran, but ran again over part 6, so that the yarn was not subject to any increase in speed during texturing.

The properties of the two yarns obtained are given in the following table:

Crimp stability

Elongation at break

Tear load

tensile strenght

Titer of the yarn

Heat shrinkage

} ". ~" ■ '*
■ with a 4% increase in
j yarn speed
in the texturing
jzone ■ without speed
. nearness • 51% 41% 28.7% 28.0% 96g i '/ 96g 4.42 g / decitex ^: 4.42 g / decitex 21.7 21.8 4.5% 5.5 *

It can therefore be seen that by using the inventive Process a yarn with an improved crimp

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Stability and a lower shrinkage can be obtained can without the yarn properties being impaired .be. The yarn. · "Was then knitted into stockings, which after the! dyeing and finishing an excellent appearance and possessed an excellent equanimity.

The heat shrinkage of the yarn is determined by the fact that 1 m length of the yarn increases, which has been stored for at least 24 hours under normal conditions. Me length of yarn is transferred into a single loop and subjected to a tension of IS g / Decitex, and the length of The loop is measured (1 ,,). The yarn loop is then immersed in boiling water for 15 seconds, dried for 24 hours under thermal conditions, again subjected to a tension of 18 g / decitex, whereupon the length of the loop is measured (Ip) The percentage shrinkage then results "from the following Vp-r> f ■ T- - T-
* ^ert * ^ A ^

χ 100

The crimp stability of the yarn is enhanced by the above described technique measured.

Example 2

The "procedure of Example 1 was repeated, each- ' but a poly amide yarn from -W- Decitex and with 14 threads and a twist sleeve speed of 12,500 rpm was used. Various attempts have been made at which the speed at which the yarn was withdrawn from the texturing zone compared to the speed, with which it was sucked off from the stretching zone, from 6% below the take-off speed of the Yerstreekzone up to 10%: "Above the take-off speed

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was changed from the stretching zone. Lie ripple stability one, each sample was measured by the above method. Figure 2 is a graph of curl stability against the increase in yarn speed in the texturing zone. It can be seen that the curve peaks at approximately a 4% increase in speed.

Example 3

The procedure of Example 1 was repeated, but using a polyamide yarn of 1? Decitex with 3 threads was used. The drawing roller 5 was driven so that the smaller diameter part ran at a peripheral speed of 650 m / min to draw the yarn to a draw ratio of 2.99. The heated pen was maintained at a temperature in the range of 185 to 195 ^C C and the roll 5 was graduated such that the same increase in yarn speed of 4% as in Example 1 was achieved.

There were three attempts at different rotation speeds en the twist sleeve. Each experiment was compared to a similar procedure with no increase the yarn speed in the texturing zone took place. The comparison results are as follows:

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- rifle

- dizzy-
speed

Crimp stability

shrinkage

Yarn tension

RPM

with 4%, without, with 4% without, with ^% without,

Speed- speed- speed- speed- ■ speed-shYjin-

eligibility -. eligibility;

increase increase increase increase increase increase

17th 400 38, 5% 32, 5% 7th ,8th% 7th »4 / ö : ² > δ S. 2 , 3 S. 20th 1C0 40, 5% 34, 3% 7th ,1% 7th , 2% • 3 » 0 G 2 , 5 S. 22nd SOO 42 % 38, 5% 5 .6% 5 ,8th% 3, 2 S. 2 ,8th S.

It can therefore be seen that in all cases the inventive "The method gave a yarn with improved crimp stability. Furthermore, these results show that the ■ Increase in speed a higher yarn tension before the Heater results, which creates an improved run.

Beisüie'1-4

The procedure of Example 1 was repeated using 17 decitex and 3-ply polyamide yarn. That part of the draw roller which draws the yarn from the draw zone was set in rotation at a peripheral speed of 674 m / min. The Holle was graded so that S5 cent increase in speed between the beginning and the end of texturing zone took place * The temperature of the heated pin was about 230 ⁰ G. The yarn was coated so that it ran about once around the pin. The yarn contained 7IOO twists, had a loop stability of 41.5% and a shrinkage of 5.3% · tension measurements on the yarn during processing

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showed that the tension in front of the heater was 204 g, immediately was 6.8 g after the heater and 12.5 g after the twisting sleeve.

As can be seen from Examples 3 and 4, the increase in the speed of the yarn in the texturing zone results in an increase in the yarn tension compared to a process in which there is no increase in speed during the texturing. It is believed that this increase in tension will result in more uniform running and fewer yarn tears because the yarn has a tendency to stick to the processing rolls which may result from fluctuations in the conditions to which the yarn is subjected. This tendency is reduced by the higher voltages according to the invention. The invention thus provides a simple method of overcoming this disadvantage. Voltage measurements were also carried out during the manufacture of a Fölyasidgarns of 14 filaments with 44 decitex, which ran around about a pin heater having 10.2 cm diameter and a temperature of 230 ^c G exhibited. The results were as follows:

Change in speed of the yarn in the texturing zone

Tension of the yarn

before to the G between after this Stoker Heater and Stoker ε Twisting ε rifle Ge reduced by 4% 2 10.5 g 18.5: g speed without change 3.5 13.5 g ■ 24.0 g Ge increased by 4; to
speed 4.8 16.5 S. 29.5 ε

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The yarn produced by this procedure increased under 4% the speed generated gave more uniform Textiles and also ran smoother during texturing than the other yarns. -

The increase in voltage in front of the heater is important, though a pen heater is used as the thread loop and the Pin heater reduces the yarn tension in front of your heater and therefore there is a risk that the tension will become so low that the thread will occasionally stick to the roll, through which it is fed to the texturing zone. The invention thus represents a comparatively simple method of elimination this problem.

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Claims (11)

Claims 1. Process for the production of a textured yarn, in which a synthetic yarn is successively stretched and is textured by the false twist principle and wherein the yarn is continuous from the stretch to the; Texturing zone is led, - characterized by d & 3 das Yarn the texturing zone at a greater speed leaves when it enters the texturing zone. 2. The method according to claim 1, characterized in that the pulling roller of the stretching zone also the feed roller to the Texturi eration zone is. 3 · Method according to claim 1 or 2, characterized in that the heater is a heated pen, with dec the yarn comes into contact. 4. The method according to any one of claims 2 or * _t, characterized in that the yarn is withdrawn from the friction surface by the Solle, which is used as a feed roller to the texturing zone, the role being stepped and the part by which the yarn is in front of Texturing runs around has a smaller diameter than the part around which it runs after texturing. 5. Method according to one of the preceding claims, characterized in that da2 the increase in speed of the When the yarn passes through the texturing zone, that there is no permanent stretching of the yarn. 6. The method according to any one of claims 2 to 5 »as a result marked that the yarn speed '"from the beginning up to the end of the texturing zone ure between 2 and 10% increases. - 7 * Method according to one of the preceding claims, characterized in that the yarn is through a twisting brake element passes through, and., although behind the drawing roller and before it reaches the heater of the texturing zone. , "''. 8 * Device for successive stretching and texturing of a yarn, which has a .Drawing zone with a feed device and a drawing device and a texturing zone with a feed roller, a heater, a friction texturing device and a take-off device. ■ device, \ * ^r above the feed roller also serves as a take-off device, characterized in that the feed,. roller is graded and the part with the smaller diameter acts as a feed roller for the texturing zone. 9 * Method according to claim 8, characterized in that .that the heater in the texturing zone a-us heated a era Consists of a pin with which the yarn koiamt in contact ..; 10. The device according to claim 8 öder'9 * characterized in that that the feed roller of the texturing zone is also the • pulling device for the stretching zone. 11. Device according to one of the .Ansprüche δ to 11, thereby characterized in that a twisting brake element. with which the yarn comes into contact, between the feed for the Texturing zone and the heater is arranged. 309821/1092