DE1901204A1 - Process for the production of yarn - Google Patents

Description

PATENT LAWYERS

DR.-ING. H. FINCKE a Munich ₅ , 1 9 O 1 2Ό 4

DIPL.-ING. H. BOHR Müllerrfraee 31, (J,. "

DIPL-ING. S. STAEGER "' ^MU

Long-distance call * 26 60 60

Cap 7854/7855 -

Description of the patent application of

Clutßom-Penn International Limited, Highfields, Coalville, Leicestershire

concerning Process for the production of yarn

Priority: 30 _o January 1968 - United Kingdom

The invention relates to the manufacture of thermoplastic elastomeric yarns (this term also includes "threads") » which contain at least 85 # segmented polyurethane " Solo yarns are commonly referred to as spandex yarns and for the sake of simplicity are also called that in the following.

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Covered or braided spandex garae are generally accepted. thermoflate in order to establish their stray properties

In the British patent 916,287 a method for the permanent change in the dimensions of threads, and the like murder "of a synthetic elastic polymer described · said method is carried out by" exposing the filaments to a temperature of at least 10O ⁰ C "while being stretched" and that the threads are ^{cooled to a temperature below 70 °} C. while they are still under tension. In this procedure, the treatment time at the elevated temperature must be long enough "to cause the thread to retain a significant amount of stretch, the minimum treatment time being 5 minutes, but the preferred time being approximately 15-60 minutes *

Another method, which is described in British patent specification 1 103 485, attempts to measure the tensile strength and modulus of elastomeric threads (which have an elongation at break of at least 1503 *, a regression from elongation of 90? 6 or more and a decrease in savings (stress decay) of less than 30 #) in a relatively short period of time. This further procedure consists in bringing a synthetic elastomeric thread to a temperature of at least ⁰

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c 3 -

heated and that it is stretched from 200 ~ 600 # on the same side while it runs between two thread holding devices, whose speeds are adjusted so that the desired degree of scattering over a period of not more than 1 min is obtained, wherein the south leaving the second holding device can relax freely and are wound up in a substantially tension-free form, *

The general aim of the present invention is to provide an improved process for making spandex gaxnen, as a result of which the advantages given below over known processes are obtained »

A particular object of the invention is to provide spandex yarns of old titers or "gravity numbers" which are heretofore commercial were not available «»

Another special goal is the production of Spandez yarns with improved properties compared to standard products _{or the like}

The method according to the invention consists in that one naked Spandex yarn during a tent space not exceeding 30 seconds stretches to less than 20OJi while doing one Temperature in the range of 160-300 ° C thermoformed.

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According to a feature of the traversed invention the Prosentsatz elongation and the height of the temperature to which the spandex yarn is subjected, are so controlled within specific Bareiche that the yarn the desired properties are imparted _o Thus it can be found that under certain conditions which are determined by trial, some properties, such as ZoBo the Retßdehnur>&, are better than with a standard product

Advantageously, the bare spandex yarn can be stretched while running or over an electrically heated plate walks past an electrically heated plate ο Preferably the yarn runs in contact with an electrically heated plate In this regard, a heating plate such as that used in a false twisting process can be used get ο

According to another important feature of the present invention can the already generally defined procedure on a cover * machine running djtu on a machine running on a initially bare spandex yarn spiralsfönnig a cover thread or Applies deodorant threads ο

Although the method according to the invention is particularly suitable for

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performing on a AMeokmasehine, but in this regard there are no restrictions, since the process can also be performed, for example, as part of a Aufspulvorgaags, for example, when bare spandex yarn is withdrawn from a yarn package, such as _o B 'of a cylindrical yarn package or a warp beam =

So that the invention is better understood, an embodiment of a device for carrying out the improved method on a covering machine will now be described, whereby reference is made to the accompanying drawing, which shows the device schematically »

It can be seen from the drawing that a bare spandex yarn T is pulled off a yarn package 1 and wound onto a further yarn package 2. In the illustrated embodiment, the Abdeokmasohine consists of two covering spindles 3 and 4t which carry bobbins 5 and 6 for the covering threads ο Bas bare spandex yarn Y runs freely through spindles 3 and 4 ο The latter and thus also the bobbins 5 and 6, which are carried by the spindles, in the axial direction have a distance from each other and are arranged so that they are a part of the running path of the yarn, indicated by arrows, 1st rotate ₀

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The device comprises both means else sum Stretching, d _o h _e stretching the current naokten yarns T ₉ and a heater 7 'passes through the the stretched yarn before the Abdeckspulen 5 and 6. FIG. The heater is box-shaped and has an electrically heated plate 7 'over which the yarn runs while touching it at the same time.

In the embodiment shown is a first feed wheel 8 and a second feed wheel 9 is shown around which the bare yarn Y passes, the second wheel 9 suitably running faster as the first to stretch the yarn, the heater 7 is between the two wheels mentioned so that the bare yarn is thermofixed before it is covered. In this embodiment, the two wheels 8 and 9 *, which have the heater between them, are after the feed yarn package 1 and immediately . In front of the first rotating Abdeokspindel 3 arranged

Alternatively, the feed wheel 8 can be omitted in which If the stretching of the bare spandex yarn is brought about by driving the draw thread winding 1 more slowly than the single feed wheel 9

In any case, the device can in an advantageous manner Have take-off roller 10 and a reciprocating guide 11, which is parallel to the axis of the winding yarn body 2 back and forth

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brought about so that the stretched, and thermofixed and now also covered thread is evenly wound onto the thread package *

It can be seen that the yarn Y is generally in an upward direction. from feed thread package 1 sram take-up thread package 2 runs, however, it runs horizontally through the heater 7, although there are no restrictions in this regard «,

As ready mentioned, among the preferred strain and temperature conditions, an increase in elongation at break of the resulting yarn are obtained, which is in the coverage process is of particular importance, as in the Bedeckungezone a higher train can be used than currently ₀ Example catfish the following pale with a commercially available spandex yarn of 1120 denier when it passes at 100% elongation over an electrically heated metal plate of 2 cm in length and at a winding speed of 6.09 m / min, such that the bare yarn is only 3 see is stretched and thermoset at the same time »

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ϊ,

'slat temperature
measured by a

Thermopnil tempera-

turaonde)

untreated .. 550

230OC 550

245 ° C 600

250OC 700

255 ° C 750

For example, there is another commercially available spandex yarn out of 840 those treated under the same conditions, the following results:

Temperature elongation at break

untreated 550

215 ° C 600

2250C 700

230 ° 0 750

240 ° ö 800

In these two examples, the temperatures used be above the sticking temperature of 210 ⁰ C the parsers are both yarns which temperature is the one at which the fiber remains straight stick to a heated brass block when it against the surface of the block 5 see long with a weight of 200 g is pressed ο

The preferred conditions for the particular spandex yarn are those who have a high amount of thermal

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fixation applied stretch is retained when the yarn is released, and in which a high proportion during a hot wet EyttflpanmmgigbefriRyitiiiEpg is permanent »

For the two yarns treated in the above manner are as follows Numbers available:

Treatment temperature

1120 den

180 ⁰ C
23O ° E

245 ⁰ O
25,000
255 ° C

840 Dan

180 ° 0
215 ° C
225 ° ö
23000
24000

Percentage of stretch retained on release (percent fixation)

20 69 87 93 95

35 79 87 92 96

Percentage of fixation compared to a hot, wet P g

is permanent

94.5

97.25

98

98.5

93 96 97 97 98

Ixierungate from those indicated in the above tables Thereof * · temperatures TlnD the preferred temperatures 255 ⁰ C for the 1120-to Oara and 23O ° E for daa 840 the yarn.

No titers of a “covered Spandex Qara * can get through here established processes are produced. Beiapielaveiee let ee, if «an tor« laemmotte * 20 ten-Spandexeun (dae

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BATH

The finest spandex yarn available on the market today has 20 denier) _{if p} then it is possible to produce a covered 10 denier spandex yarn «,

With the method according to the invention, covered spandex yarns with considerably heavier titers which are not currently available ". For example, if assuming a bare 1120 denier spandex yarn is possible 650 denier covered spandex yarn.

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Claims (1)

Claims ο A method of making a thermoplastic elastomeric yarn comprising at least 65 # segmented polyurethane, in which method the yarn is simultaneously stretched and heated for a short period of time, characterized in that the Oarn in the naked state for a period of not more than 30 seconds is stretched by an amount of less than 200 # and is heat-set at a temperature in the range of 160-3 (X) ⁰ C o Method according to Claim 1, characterized in that it is carried out on a covering machine (3, 4 » 5 and 6) as part of a process of covering the initially bare one Yarn is executed o Method according to Claim 1, characterized in that it is carried out as part of a winding process will" Method according to claim 1 _f, characterized in that the bare yarn is treated under such stretching and temperature conditions that an increased hot stretching is achieved ο Method according to claim 1, characterized in that the bare yarn is heated by being in contact with an electrically heated plate (7 ¹ ) 909832/1333 The method of claim t _f g characterized in that the bare yarn is stretched by an amount of about 100 $ " ο Thermoplastic elastomeric Q-arn, which is at least $ 85 includes segmented polyurethane, characterized w labeled in characterized "it not for a period of more than 30 seconds in the naked state by an amount of less than 20O ^ and at the same time "has been thermoset at a temperature in the range of 160-3OQ ⁰ C" 909832/1333