DE1410640A1 - Elastic yarn and process for its manufacture - Google Patents

Description

The invention relates to a new yarn and a Process for its manufacture.

The invention is based on an elastic yarn that from a highly stretchable elastic thread and from one Is composed of roving that is twisted with the elastic thread that in the stretched state of the elastic This thread forms a plied or layered thread with the roving. According to the invention is one such elastic yarn characterized in that the elastic thread with one of a plurality of in loose arrangement located endless single threads existing roving is twisted less rotation and that the elastic thread and the roving is proportioned in such a way that an x: y ratio of at least 1.7 and not more than 3.0 results.

(Art. 7 i 1 para. 2 no. 1 ^ 3 sentence 3 of the amendment act. 4. 9.1967)

Ö.Ö9Ö 11/1 Ö03 -

where χ is the mean length (in cm) of the roving per unit of length of the elastic yarn, divided by the number of layers of twisted twist per unit of length of the yarn and y corresponds to the value \ (2Ί / Β.) A + - _o , in

A ^

which means;

R is the radius (in cm) of the elastic thread in the relaxed state,

h is the length (in cm) of the length in the unit of length of the yarn contained relaxed elastic thread, divided by the number of twists per unit length of the Yarn, and

A is the ratio of the length (in cm) of the section of the relaxed elastic thread contained in the unit length of the yarn to the length (in cm) of this Section of the elastic thread with the yarn in the drawn state when y is a minimum. The multi-filament thread and the elastic thread are arranged and dimensioned in the composite yarn so that in an extended state of elastic bathing the multifilament thread and the elastic thread preferably assume a ply yarn formation and that with a contracted one State of the elastic thread, but with a generally linear state of the composite yarn thread consisting of continuous single threads is wrapped around the elastic thread in somewhat loose turns. ■ -'ε

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The yarn according to the invention can be used to new textile fabrics or the like by weaving, knitting or other interlacing of such threads alone or in connection with to produce more common yarns for forming fabrics. For example, a fabric can be made exclusively with the yarns be knitted according to the invention; or a fabric can using yarns according to the invention as weft

■ be woven etc. ^*:; .

The preferred embodiments of the invention are elastic yarns in the sense of how the term "elastic" is understood in textile technology to refer to the elasticity possessed by a rubber core or other elastic core, or a single textile cover such as this is described, for example, in US Pat. Nos. 2,024,155 and 2,024,156, or has a double textile cover, as indicated in - US Pat Invention can be used in similar applications for which such elastic yarns are used, but their use in such applications generally results in a new structure> and / or more economical fabrics are obtained by the yarn according to the invention. ^, Dis ;. Yarns according to the invention can also be used for additional applications. shanks. to .use, _: ,, ·, · "■■ -;.:"-'-.- · - ■ - - ■ .- · ■ '. ■ In the contracted state of the elastic ^' adens, every-

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but with a generally linear one. State of the together. . The set yarn is that consisting of continuous single threads. Thread wrapped around the elastic thread in turns of somewhat arbitrary sizes, which are larger than the diameter of the elastic thread within the turns. and the monofilaments of multifilament bathing expand from their normal dense parallel arrangement. The yarn gives the fabric a pleasing texture "The type of texture depends on the combination of the elastic thread and the multi-thread bathing in the composite yarn." elastic bathing within the coils when somewhat contracted, and in some such embodiments the multifilamentary thread may occasionally and arbitrarily pucker or curl around itself to form crunodal loops through which the elastic thread does not pass, as the composite yarn is in his favorite ^A usführungsformen when it is free from all the forces that seek to keep it straight, very capable and knick alive and curls and curls around itself, if it has not been treated, in order to overcome this situation "

Using the preferred embodiments of the invention a technique is used that differs from that usually known in the processing of elastic

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■ - 5 - H.10640

The technique used by the yarns has been slightly modified. The Game according to the invention, during the interlacing process a stretched, e.g. by tightening them; in the finished

Tissues tighten the elastic threads, in general however, in an unbuckled state of the composite yarn. So the fabric manufacturer is supposed to be stretched by a Condition of the new ^ arnes in the creation of its tissues, which is contrary to the practice which has so far been used in conventional elastic yarns.

Fabrics made from the preferred embodiments of the Yarns produced in accordance with the invention have the soft feel that is produced in fabrics through the use of such yarns The effect is similar to the effect obtained through the use of so-called textured or puffed yarns in fabrics such as those yarns made by twisting or twisting a yarn from continuous thermoplastic Thread shape, fixing the twisted yarn by means of heat and untwisting the yarn or by crimping one Yarn made from continuous thermoplastic threads or by heat setting a crimped thermoplastic Yarn are made from continuous threads. The tissues They also have elastic moduli and stretch properties that are comparable to fabrics in which rubber threads are used or coated rubber threads of known type are used have been.

The yarn can be used on conventional twisting devices after a

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Yerfahxen are produced, in which one of several continuous single threads of existing untwisted thread is fed to the twisting point with a preferably untwisted elastic thread at such a speed as it will be seen below that the yarn disclosed herein is produced.

The invention is described below with reference to the drawing "for example explained in more detail:

Fig. 1 is a schematic view of a twisting device, which can be used to manufacture the yarn according to the invention. i'ig. Figure 2 is a somewhat schematic view of a length

of yarn according to one embodiment of the invention in its fully or nearly fully stretched state. Fig. 3 is a somewhat schematic view of the yarn of Fig. 2 in a partially contracted state. '
Fig. 4 is a somewhat schematic view of a length

together of the yarn of Figure 2 in further • -. ^Λ ^ "drawn state as in Fig _o 3. In Figure 1, an apparatus shown which is similar to the parts of a common twisting machine, as used for covering of rubber thread. A relatively non-stretchable multi-thread thread 10 is guided from a winding to the nipping point of revolving balls or rollers 12, 13. Elastic thread 14 is guided by a '

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Supply spool _: 15 * the, iron one., Revolving drum; 16. driven wj ^ d ^ ;, soft against the elastic; ^ aden, auf, the spool, 15, runs, zu.de ^ 3p.emmstelle der ^ roles 12 ,, 13.geb 'led. Between ^ the coil 15..and the _; Rolls _fi 12>; 13-the elastic thread 14 is stretched. . ^ ₁ -: .-. _., _ ■■ s, ..., _-,

From the clamping point of the rollers 12, 13, the pads 14 and 10 go into a guide,; 17, and; of. Aörtdurch a runner 19 * rush on a ring 20 to a coil 21 on a rotating spindle 22. Between ^ DER _Klemmst; der.Rollen 12, 13 and der.Spule 21, the threads 14; and 10 to form the composite yarn. ^ twisted or twisted.

inJig .; 2. is the state of the composite yarn 23; (y completely or almost completely stretched.) _r - how it. on ... the spool _: 2-1 · is wound up, - something. Schematic, yeransohaulicht .. The threads 14 and 10 are twisted together in a layered yarn, that is, no thread is wrapped as a cover around the other as the core, but both generally follow similar paths _: .U3ttieeinander. The gradient of the "ply, screw · ', of, .10 thread or of the thread 14 (since this generally similar ways .f ollow). Is. VeThäJ.tnismpLßig long, the Ajazahl ie _r yon f rehupgen , the management twine depending Längeneinheit.-the threads .10. bekannt.er and elastic Crariie Lunj Einzelumhüp-in your new yarn compared. to the 14th. 'yerhältnis- is measured ig · _(low. *. B's but has a , Hinde instead of paying .from _wrap;..? be present depending Mng ^ eneinhe.it the multifilament yarn * um .. _N ^ to achieve the desired texture JSs..müssen, at least, 5. turns situation twist per inch of the multifilament yarn 10

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H10640

be present in order to obtain that texture, and preferably at least 10 turns of location twist per inch of the multifilament yarn 10 exists, so that the multifilament yarn in general an approximately helical path around the elastomeric yarn 14 is 10 along with contracted state of the yarn 23rd

In Fig. 3 is an embodiment of the composite Yarn 23 somewhat schematically in partially contracted State illustrated in which the yarn 23 is still stretched by a large fraction of its total elongation. Fig. 3 can be viewed as an illustration of an embodiment of the invention, which on about half of the Length at which measurements were made in Table I below. Of the In this state of the yarn 23, when the thread 14 is drawn together, the multi-thread thread 10 is loose around the thread

wrapped with a large number of individual turns or turns, which are substantially / larger in diameter are as the part of the thread 14 within these windings. The size of the individual windings is not uniform / over the entire length of the yarn; for example, in Fig. 3, which is made from a pattern of yarn, there are alternate ones Windings, as indicated at 53, relatively close in proximity of the thread 14, while intervening windings 54 a lot are larger than thread 14. Generally the thread is puffy or flaky, somewhat helical Form wrapped around the thread 14, the individual winding

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lungs or coils on average a much larger one Have a diameter of 14.

This excess of the multi-threaded bathing 10 can be in Values of the ratio of the mean length (X) of the multi-thread thread 10 per turn to the theoretical length (Y) one turn of a screw with a diameter equal to the middle one. Diameter of the elastomeric thread be expressed. Y is calculated using the known formula for the length of a screw turn

I) G = Y I2TC M) ^Z + F ²
where M is the radius of the screw and N is the pitch of the screw. The formula of Y, based on the formula I,

II) Y = "V (2 Jf; R) ² + h ²

This theoretical winding length can be calculated for any given condition of the composite yarn become, if in a state the number of turns, the length of the multi-filament ^ adens and the length of the relaxed elastomeric thread per unit length of the composite Yarn and the mean diameter of the relaxed elastomeric thread are known. The value h is eLae-Ke-z & £ «*« k-e- the length of the relaxed elastomeric thread . (expressed in English inches) per unit of length of yarn, divided by the number of twists of the ply of the " elastomeric thread with the multi-thread thread in this length unit. The value R is the strength (i.e. the nominal

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Hadius) of the relaxed elastomeric thread (expressed in English customs).

To generate a given value according to the invention should the multi-threaded thread 10 and the elastomeric thread are combined in such a way that when Y is as in Equation II relative to the relaxed elastomeric thread 14, the ratio X: Y is at least 1.4 and preferably less than 2.5 (where X is also in English Is expressed in inches).

Obviously, for a given construction, when the composite yarn is stretched or allowed to contract, the value of Y will vary somewhat because the diameter of the elastic thread changes. However, the value of X remains constant for a given structure regardless of its stretched state. If a unit of length L _Q of relaxed elastomeric thread 14 assumes a length L in the stretched state of the yarn and if

Ill) the L ₀ R _{1 of} the elastomeric thread is then is Sadius L _{1 is the} same Γα IV) T? - Τϊ and
V) , at H State Then Y. this

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VI) 'Y ₁ = aV (2 ^ H) ² + Κ

ι ' k ^a

In this way, the fourth of Y changes for a given one .Build up with the ratio A (percentage elongation), and the ratio X: Y changes in a similar manner * If one differentiates the expression within the root in equation VI) and sets it as UuIl, the maximum Ratio of XsY found for a given setup will.

In a yarn according to the invention this is maximum Ratio of XiY at least 1.7. Preferably it is less than 3.0.

When the composite yarn 23 contracts, the individual threads of the multi-filament thread separate in the individual windings and bends along the length of the thread 10 from their usually dense parallel arrangement, i.e. the multi-thread thread IO diverges ("blooms"), as is the case with windings 53 and 54 can be seen.

In FIG. 4, the composite yarn 23 is shown even more relaxed than in FIG. 3. It can be seen that more of the windings has moved farther away from the thread 14 and that in the thread 10 there is a random and has formed an arbitrary crunodal loop, as indicated at 51, through which the thread 14 does not passes through.

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The thread 10 is a thread consisting of several continuous single threads with a low twist. silk and most synthetic fibers, such as fibers made of polyamide (Sylon), Acetate, viscose (rayon), oriented super polyester (Dakron), etc., are available in continuous filament form. The thread 10 is also a multifilament yarn, and this is understood to mean that it has a sufficient number of Single filaments, generally seven or more, have in order to be able to diverge (to blossom) and the composite Yarn on the individual "" indications of the thread 10 to give a texture when the elastic thread 14 is drawn together. The synthetic fibers, like those mentioned above, will be generally made in multi-thread form; for example

the polyamide yarns, which have been used in the known elastic yarns with a rubber core, are available with 7 to 68 individual threads, 0. per thread. The multi-filament yarns, which are useful as envelopes for the known elastic yarns with rubber core that is, those _{suitable with up to 70 individual threads and from 20 to 210 den., Are suitable for use in the invention t *.

The thread 10 is also of low twist, and by low twist it is meant that it does not has such a rotation that it has the desired separation or the divergence (blooming) of the individual threads of the thread, as described above, when the

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Thread 14 would prevent. Of course one would too. multifilament thread »which is completely free from twist will be satisfactory. In general, however, the yarns made of synthetic fibers are nowadays with a so-called manufacturer twist of 0.5 to 2.5 twists per engl. Customs sold. It has been found that this rotation does not interfere with the desired divergence (blooming)} therefore these games are preferably used. Undoubtedly a slightly larger rotation, up to about 5 rotations per engl. Inch, does not unduly interfere with the flaking (blooming) of the strand and would be a low twist strand suitable for use in accordance with the invention. In general, a thread with over 5 twists per English bothers. If there is a desired divergence (blooming), filaments with this high twist are generally unsuitable for the invention. With respect to the rotation of the multi-filament yarn is the D _re] iung, permitted by the twisting of the thread 10 and the thread is given 14 disregarded, because relative to the axis of the thread 10 when in its helical formation around the thread 14, the thread 10 is not twisted, although if the thread 10 were drawn in a straight line by a force exerted on its ends, it would be found to have the number of twists that would be obtained by twisting the threads 10 and 14 together 14 is granted.

The thread 10 with continuous single threads should be free

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be of material, which the desired divergence Prevents (blooming) when the elastic thread 14 is drawn together, for example by the individual threads 24 being tacked together.

The elastic thread 14 is to be stretched a lastomer ^E-thread which is capable to several times its relaxed length and to contract vigorously at lifting of the voltage. A thread made of natural or synthetic rubber is used; Polyurethane elastomer thread is a particularly desirable synthetic rubber thread for various types because of its good abrasion resistance and other properties, as discussed in more detail below. Conventional rubber threads suitable for "use as thread 14 are of course known in the elastic yarn art. The sometimes preferred polyurethane elastomer threads are currently less well known in the elastic yarn art, but suitable polyurethane elastomer threads are known. An example of a suitable polyurethane elastomer thread is given in US Patent Application Serial No. 622,370 »

Elastomer threads are produced which can be stretched by at least five times their original length and up to 600 to 800 #, ie by seven to nine times their original length under tension without breaking. So far they have generally been produced as monofilament threads with an average diameter of 0.40 to 0.13 mm.

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It has been found that when polyurethane elastomer threads for the elastic ^ aden 14 la © are used, the compound G-arn can be heated to its properties to change «If, for example, a composite yarn with a polyurethane thread as the elastic member during a period of up to 10 minutes "is heated at 149 C while the jade is kept in a stretched state, such as it is shown in Fig. 5, it "loses much of its inclination to curl and kink around itself, i.e. a tendency that can be undesirable »Furthermore, follows such a treatment does not affect the composite yarn Eight together for a length less than that Length of the composite yarn at the time of treatment.

Although for some applications the elastic thread 14 could optionally be pre-twisted, namely in one In a manner similar to that in which the rubber core is used in the manufacture of known elastic yarns with single sheaths is pre-twisted, it is preferred that the elastic thread not be pre-twisted; the usage of Untwisted elastic thread provides great economic advantages in the manufacture of the preferred embodiments according to the invention.

Preferably, the multi-thread thread 1Q and the together · drawable thread 14 in a given length of composite yarn 23 so Feemessen that the composite yarn has a so-called "uniform break", i.e. that both

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Threads 10 and 14 have their breaking point almost the same Reach elongation of the yarn 25. For some purposes it may be desirable to use the multi-thread bathing proportions and to change the elastic bathing 14 somewhat; e.g. can it may be desirable to increase the length of the elastic bath 14 somewhat to increase, so that near the break point of the multi-filament thread 10 absorbs a slightly larger part of the breaking load.

The new yarn according to the invention combines in a unique way different properties that are used in textile technology are desired. It provides the texture properties of so-called textured yarns, such as bulk yarns, and it provides the module properties of the single or double covered elastomer threads. It is similar to single-wrapped ones provided known elastomer threads insofar as an elastomer thread with a non-stretchable thread is adjusted. It differs from single-wrapped elastic threads in its texture, the Use of a thread consisting of continuous single threads with a low twist, the imbalance of the previous J

c ferred ^A usführungsformen in the untreated state of the ^f

Yarn and the loose and somewhat irregular union of the multifilament thread with the elastomeric thread, which leads to the contributes new texture of the yarn according to the invention.

The following specific examples of ^ö arn illustrate the invention in more detail. When considering the values in the table below, it should be noted that the values from measurement

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sings. lengths, of about 90 cm or less, or at one A fraction of a kilo of the assembled yarn collected and accordingly there may be some minor error have multiplied in the measurement in the values given in the tables; put the specified values, where it was possible (e.g. at 1 (d), 1 (e), 2 (c), S (a), 3 (d)) mean values of at least three readings, "Nevertheless, the values are within those commercially available from elastic" accepted tolerances, and in the following such averaged values are used to define the invention.

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- • - Examples O A. B. 1410640 «< D. 1. Elastomers? * Thread ! table I. CO
O (ε.) material (single thread) Haturl.
Kfiiitschk. Haturl.
Rubber. C. JSTaturl.
Rubber. 981 (b) thickness (diam., ent
tensioned) (2R) .01 "
(10ö's) .01 "
(100's) .01 »
(100's) (c) Pre-rotation (rotation per
Inch of the appropriate thread) no no Natural
Rubber. no (d) * inch-equivalent thread each
Yard together & macaws 6 »1 6.2 .01 "
(100's) 6.9 (e) * turn, per yard of ge
stretched elastomeric thread 359 707 no 729 6.8 569

(f) inch according to Combine it together by the yard. G am s if! / Υ a maximum

2. Multi-thread thread (a) Material

10.2

An end
the.
iäd.

(b) Rotation (rotations per inch ^Ή ν ^1οη
before twisting with the
slastomeric thread) 0.5Z

(c) * inches of multiple thread each

Xard combined yarns, -38.2
Zua ^ kitchen set yarn

(a) * lards per engl. Pound 20,743

(b) G-ew.fo elastomeric thread 30

(c) Gew * ^ roehrf. Thread 70

11.8

An end
the.
thread
nylon

39.4

10.7

One end 140 den. 68 thread nylon

0.5Z 38.0

12.6

One end 140 den. 68 thread nylon

39.5

20th 712 19800 20th 350 31 30th '. 30th 69 70 70

Table I.

.01 ».01" CiOO's) (100's)

no

10.7

I'm at the end of 140 den. 68 thread Nylon · 0.5Z
38.0

no

6.9

729

12.6

An end to HO den. 68 thread nylon

0.5Z 39.5

Natural Natural Natural Rubber. Rubber. Rubber.

.01 »(100's)

no

7.5

967

15.3

One end 140 den. 68 thread, Nylon.

0.5Z 42.0

19800 20th 330 ^: 19th 302 30th 30th 31 70 70 69

Natural Natural Rubber. Rubber.

.01 »(100's)

no

8.2

1394

20.2

One end 140 den. 68 fäd, lylon

0.5Z 45.0

.0133 "(75 ^f s)

no

7.4

507

12.7

2 ends 140 den. 68 fad. nylon

0.5Z 40.8

16 840 9 566 33 28 67 72

.0067 "
(150 ¹ S) ***

no
7.1

1.168

13.9

An end
40 den.
13 thread
nylon

0.5Z

44.6

53 229

Polyurethane natural rubber rubber.

.01 »(100» s)

none 11.2

-529

19.2 '

I'm at the end of 140 den. 68 thread nylon

0.5Z

47.2

15 120 46 54

-F-CD

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Examples A Β_

Table I (continued)

... Compound yarn

(d) * Rotation of the elastomeric thread with the multiple thread per yard additional total yarn 596

(e) Mean coil length of the Multiple thread in size (X) / 3 (d) divided by

2 (cl7 0.0648 0.0541

(f) length in inches of a turn of a screw with diam. 2R and slope equal to i (d) divided by 3 (d) (Y, based on fully compensated.

elastomeric thread) 0.0330 0.0326

(g) Ratio Χ / Υ (based on completely de-tensioned elastic thread) ß (e) divided by 3 (f) / 1.96 1.66

(h) length in inches of a turn of a screw with the same ■ diameter as the elastomeric thread, if the total yarn is relaxed on condition i (f), and with a pitch equal to t (f) divided by 3 (d) / Ί Minimum) / 0.0297 0.0279

(i) Ratio X / Y maximum

/ 3 (e) divided by 3 (h) 7 2.18 1.94

1.88

2.04

763

0.0626 0.0518

0.0333 0.0327

1.58

0.0306 0.0285

1.82

H106A0

E F

980

1.33

1.59

1423

0.0429 0.0316

0.0324 0.0319

0.991 '

0.0270 0.0245

1.29

* Measurements based on the fully stretched state of the assembled yarn ** calculated
*** nominal

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Table I (continued)

729

1.66

607

763

980

1423

1.88 1.58

1.33 "0.991

9.09811 / inn

0.0541 «0.0626 0.0518 0.0429 '0.0316 0.0721

0.0326 0.0333 0.0327 0.0324 0.0319 0.0438

0.0279 0.0306 0.0285 0.0270 0.0245 0 _s 0388

1.94 2.04 1.82 1.59 .1.29 1.86

Condition of the assembled yarn related

• 1300

1.73

H10640

1133

0.0320 0.0417

0.0218 0.0329 1.47 1.27

0.0165 0.0294

1.42

In the understanding 'labile the examples A, B, C, D, G and H are yarns according to the invention. G-arj. I is an elastic yarn r: it sinfachhülle which is produced according to the prior art, eB according to the "'S patent application Serial ETr, 645 721» but has a somewhat uneven sheath and is included here for comparison purposes, around 4rt of the yarns according to the invention below illustrate, -The yarns S and 3? are Ye rs'ichsgame, not according to the invention, which were produced and listed for comparison purposes in order to illustrate the nature of the invention.

“Each of the elastomex-an threads in the preceding examples can be stretched 600 to 800 degrees. It should be noted that "although the elastomeric fiber in Examples A to" F, G and H is not twisted prior to the manufacture of the elastic arm, "the rod.?. of the elastomeric bathing per liard of the additional setster: Gaines differ from the rotations of the elastomeric loading with deui aehrfädigen laden.; 'e yard of the compound ¹ game. In theory, these rotations should be the same} the difference comes from the. It was found that the measurements were carried out by disassembling and untwisting the elements of the assembled yarn. While the elastomeric load appeared completely untwisted, sr actually retained a small percentage of the 'rotation due to fixation

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or! Consolidation of elastomeric ** bathing back.

Example A is a now preferred embodiment of the invention with holier texture. Example B is the example A in that it is different from the fact that it is it is approximately the same length as elastomer iaden, differing in that it is slightly larger in size of rotation between the elaatoaeren 3? aden and the multi-thread i'aden has «The additional layered thread reduces the texture effect somewhat; in the "table this comes about somewhat in the values 3 (e), 3 (g) and 3 (i) Expression.

Example C differs from Example A in that that although both have approximately the same amount of ply twist, Example G is a slightly longer elastomeric As an example, thread has A. The thread C has a slightly diminished one Texture versus example! in the table this applies to the values 3 (e), 3 (g) and 3 (1) Expression. What is not evident from the table is that the ratio of the length of the multifilament thread (cf. 2 (c)) to the length of the elastomeric thread (cf. i (d)) in example C somewhat greater than in example A. is. To this extent, this leads to something that is sometimes desirable Result than the yarn according to example ^ if it is the compression elongation approaches to absorb a larger part of the breaking load acting on the multi-filament strand than is the case with Example A.

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A comparison of Examples O and D shows that, although they both have approximately the same length of elastomeric thread, Example D has a much larger ply thread than Example C. In Examples E and E ¹ , the ply thread is essential and compared to Example D progressively increased. The examples Cp, E and 3? were all made with approximately the same advance of the components to the plying point, but the thread was progressively enlarged for the various examples. Examples E and I ¹ illustrate the result obtained when departing from the limits of the invention; they do not have the advantages of the products according to the invention.

Example Q- is a stronger Q-arn than that
according to examples AD and Ή. Example H is a
fine, i.e. thin Q-arn, as shown in the value 3 (a)
can be seen. The values 3 (g) and 3 (i) show that,

the example H near the lower limits of the range,

according to the invention. The texture of the G-arnes H is >

not as pronounced as, for example, that of yarn A, but the yarn H is economical to manufacture and, when woven into cloth, results in a cloth of excellent quality.

Examples A, B, O, D, Q and H, though different from each other, all show excellent texture. Examples E and i ¹ show no texture.

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UI0640

A comparison of the values 3 (g) and 2 (i) for the various examples shows that if the ratio XjY, based on the fully relaxed elastomeric thread »falls below about 1.4, the yarn according to the invention is not achieved. When the ratio XiY, "based on the fully relaxed elastomeric load, is above approximately 2.50, the" union of the elastomeric bath and the multifilamentary thread is such that the yarn according to the invention is not obtained. In the production of the yarn according to the method illustrated in FIG. 1, care must be taken to ensure that the multi-filament thread 10 and the elastomeric thread 14 are combined in such a way that, on the completely relaxed elastomeric thread, the ratio X: Y in is in the range from approximately 1.40 to approximately 2.50.

By comparing the values of 3 (i) for the various examples, it can be seen that when the maximum of X: Y is below about 1.7, the textured yarn of the invention is ni maintained. When this ratio is approximately 3.0, the union of the elastomeric thread and the multifilament thread is such that the textured yarn according to the invention is not obtained. Accordingly, when combining the elastomeric thread and the multifilament thread to achieve the invention, care should be taken that

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the maximum of the "'preservation Xi Ϊ not less than about 1 * 7 and does not fall above 3.0.

A comparison of Examples 1, B, C, I, β and H with the case I increases that, according to the invention, an excess of a multi-threaded strand per winding (value 3 (e)) over that forehand * ⁸¹¹ is required to produce a well-covered ela $ table a Sam with a simple uniillug of known type au. The yarn according to the invention are characterized by this excess of multifilament ^ 'aden geksnasaichnet ₅ wherein the multifilament Sadan in contracted state of the elastomeric Padeiis in something happening ^ is a load turns to elastomeric din. An adequate number of such ΐ / indüngen be present _s xm to the multithreaded Paden the elastomeric ". Distribute thread relatively evenly along its length. There must be at least five turns per English. 2q11 length of the m & hT- thread thread provided aein, and in general & ±: iä at least ten turns per English inch of the single thread thread present,;

BATH ORIGINAL 909811/1003

Claims (4)

1. Elastic Sam who aits one? highly extensible and elastic thread is composed of a roving, which is twisted with the elastic yarn such that it forms in the stretched state of the elastic thread with the roving a plied or ply twisting, characterized in that de _t? elastic thread having one of a plurality of. loosely arranged endless single threads - existing roving is twisted with little twist and that the elastic yarn and the roving are proportioned in such a way that a ratio x? y of at least 1.7 and not more than 3 "- results, where χ is the mean linear (io cm) of Vorg £ i? Bs per unit length dew elastic yarn, divided by the number Lagenewirndrehung en depending JLängeneinhe it the yarn and y is the Value Y (zm ² A + fe * ' A ^z corresponds to, in which means " R is the radius (in cm) of the elastic bath in the relaxed state, h is the length (in cm) of the length in the unit of length of the yarn contained relaxed elastic thread, divided by the number of twist turns per unit length of the thread, and A is the ratio ύ. & Ϊ́ length (in cm) of the section of the relaxed part contained in the unit of length of the yarn New documents («!! ^ 09811/700 3 BADOBIGINAL elastic bathing to the length (in / cm) of this section of the elastic thread with the yarn in the drawn state when y is a minimum. 2. Elastic yarn nat II claim 1, characterized in that that in the fully stretched state of the yarn the elastic thread with the roving at least two twist turns each cm forms. 3e blastic yarn according to claim 1, characterized in that that the elastic thread is an elastomer thread which is at least five times its relaxed length is stretchable, and that in the fully stretched state of the yarn, the elastomer thread with the roving at least four twist turns per cm. 4. A method for producing an elastic yarn according to any one of claims 1 to 3, characterized in that a roving consisting of a plurality of loosely arranged endless single threads, which is twisted with less than two turns per cm, and one in the stretched state held elastic thread is presented against a twisting point and twisted there with one another in such proportions that the resulting yarn has an x: y ratio of at least 1.4 and not more than 2.5, where χ is the length of the multifilament thread (in cm), per 'unit of length of the yarn produced, divided by the number of twisted turns formed per unit of length of the yarn and y corresponds to the value ϊ (2 ^ R) + h, in which A = 1. 909811/100 3