US3928958A

US3928958A - Method for producing spun yarn-like bulked yarns

Info

Publication number: US3928958A
Application number: US518969A
Authority: US
Inventors: Takeo Kurata; Tamotsu Hayazaki; Kyoko Murakami
Original assignee: Asahi Chemical Industry Co Ltd
Current assignee: Asahi Kasei Corp; Asahi Chemical Industry Co Ltd
Priority date: 1973-10-29
Filing date: 1974-10-29
Publication date: 1975-12-30
Anticipated expiration: 1992-12-30
Also published as: IT1021958B; GB1471590A; HK2578A; FR2249195A1; FR2249195B1

Abstract

Bulked yarns which have many uniform loops and snarls, and are excellent in spun yarn hand can be obtained by twisting plural yarns having difference in length of 3 to 40% in an optional direction at a twist coefficient of 10 to 140, rubbing thus twisted yarns to form loops and snarls in the longer filament yarn, and subsequently additionally twisting the yarns in the direction of the first twisting so that the twist coefficient becomes at least 5 to set the loops and snarls formed by the rubbing action.

Description

United States Patent Kurata et al.

[ Dec. 30, 1975 METHOD FOR PRODUCING SPUN 3,526,084 9/[970 London er al 51/157 TS x YARN-LIKE BULKED YARNS 3.645.080 2/1972 3,683,6l2 8/1972 Buzano [75] Inventors: Taken Kurata; Tamotsu Hayazaki; 3,691,750 9/1972 Waters Kyoko Murakami, all of Takatsuki, 3.756.005 9/1973 Sequin..... Japan 3,777,465 l2/l973 Buzano.... 333L360 8/!974 Horvath 57/34 HS X [73] Asslgnee: Asahl Kasel Kogyo Kabushlki h k Kms 053 Japan Primary Examiner-D0na|d E. Watkins Filed? Attorney, Agent, or Firm-Armstrong, Nikaido & 21 Appl. No 518,969 wegm" [30] Foreign Application Priority Data [57] ABSTRACT Oct. 29, I973 Ja an 48-I207l5 Bulked yarns which have many uniform loops and Mar. I9, 1974 Japan 49-30625 snarls, and are excellent in spun yarn hand can be obtained by twisting plural yarns having difference in [52] U.S. Cl. 57/157 TS; 57/[60 length of 3 to 40% in an optional direction at a twist Int 002G U D026 U D026 /3 coefficient of 10 to I40, rubbing thus twisted yarns to Field of Search 57/157 157 I57 form loops and snarls in the longer filament yarn, and

57/l40 BY, 160, 77.4, 34 R, 34 HS, 3, 6, l2, subsequently additionally twisting the yarns in the di- 144; 28/67 rection of the first twisting so that the twist coefficient becomes at least 5 to set the loops and snarls formed [56] References Cited by the rubbing action.

UNITED STATES PATENTS 12 Claims, 6 Drawing Figures 3,357,l7l l2/l967 Marshall 57/l60 TWIST ING RUBBING TWIST ING REMAINING TWISTS ADDITIOJAL TWISTING UNTWISTING WRUBBING ADDITIONAL TWlSTING UNTWISTING 'VRUBBING ADDITIONAL TWISTING U.S. Patent Dec. 30, 1975 Sheet 1 of3 3,928,958

FIG.

U.S. Patent Dec. 30, 1975 Sheet 2 0f3 3,928,958

FIG. 2

N A U T l'ol'z 41's [820 DIFFERENCE IN LENGTH (95) FIG. 3

GRADE mwhm 2'o4b osb lol'zol lololo TWIST COEFFICIENT U.S. Patent Dec. 30, 1975 Sheet 3 0f 3 3,928,958

FIG.4

TWIST ING RUBBING ADDITIGIAL TWISTING TWISTING UNTWISTING .1 VRUBBING REMAINING ADDITIONAL TWIST "\G TWISTS RUBBING ADDITIONAL TWISTING IREMAINING TWISTS FIG. 6

METHOD FOR PRODUCING SPUN YARN-LIKE BULKED YARNS The present invention relates to a method for producing spun yarn-like bulked yarns having a number of loops and snarls. More particularly, it relates to a method for producing spun yarn-like bulked yarns by subjecting filament yarns to suitable twisting and rubbing actions to form a number of loops and snarls without using turbulent air-stream device.

Conventionally, bulked yarns have been produced by air-jet method which comprises jetting high pressure air or steam to filament yarns to form a number of loops and snarls on the surface of the filament yarns. Thus obtained bulked yarns have been well known under the tradename of Taslan".

However, according to the method for producing bulked yarns by air-jet, slight variations in shape and size of jetting nozzle, jetting pressure and yarn path have great influence on formation of loops and snarls. Therefore, control of manufacturing process and uniformity of yarn quality is difficult. And also, only a part of energy of jetted fluid contributes to formation of loops and snarls of filament yarns and powder transmission efficiency is low and cost for production becomes higher.

Such being the case, it has been strongly demanded to establish a method for economically producing bulked yarns having uniform loops and snarls without using the air-jet method.

Conventionally, for imparting spun yarn-like hand to filament yarns, besides said Taslan finishing there has been proposed a method which comprises forming torsional loops in filament yarns by employing complicated two-stage false twisting method with utilization of the torsion of filaments generated by false twisting. However, according to such method, control of yarn bulkiness is very difficult and stable operation cannot be attained Recently, a method for producing bulked yarns having loops which uses balloon generated by overfeeding the yarns at false twisting is proposed. However, this method causes great variation in yarn tension and it is also difficult to effect stable operation.

The inventors have made intensive research in an attempt to overcome the defects in the conventional techniques to accomplish a novel method for producing bulked yarns having suitable loops and snarls in a stable operation without using turbulent air-stream device as required for Taslan finishing.

That is, the object of the present invention is to pro vide a method for producing spun yarn-like bulked yarns which comprises subjecting filament yarns having difference in length to suitable twisting and rubbing action to form a number of loops and snarls and which can be stably operated in a high efficiency and in low cost.

That is, the present invention relates to a method for producing spun yarn-like bulked yarns which comprises either twisting in an optional direction plural yarns having difference in length of 3 to 40% at a twist coefficient of 10 to 140, or twisting the yarns to a suitable extent in an optional direction and then untwisting the twisted yarns so that the number of the untwisting is below said first twist number and a remaining-twist coefficient (this is defined hereinafter) is in a range of 10 to 140, and subjecting the twisted yarns to rubbing 2 to form loops and snarls in longer yarn, and subsequently subjecting the twisted yarns to additional twisting in the direction of the first twist in a twist coefficient of at least 5 to set said loops and snarls generated by the rubbing.

According to the present method, plural yarns having difference in length of 3 to 40% are twisted at a given twist coefficient range, then are rubbed to form loops and snarls in longer yarn and simultaneously to form core yarn of shorter yarn, thereafter additional twist is given to the yarns to set the position of loops and snarls formed by rubbing.

Size and amount of the loops and snarls on the bulked yarn obtained in the present invention can be optionally controlled by suitably adjusting the difference in length of the initial yarns, number of twist given on the yarns and amount of rubbing.

The above and other features of the method of the present invention will be further understood from the following description when read in connection with the accompanying drawing: wherein,

FIG. 1(a), (b), (c), (d) and (e) are photographs (:25) of side view of spun yarn-like bulked yarns ob tained by the method of the present invention and are graded into five grades depending upon degree of the loops and snarls, namely, (a) is the lst grade, (blis the 2nd grade, it) is the 3rd grade, (d) is the 4th grade and (e) is the 5th grade;

FIG. 2 is a characteristic diagram which shows rela tion between the difference in length of the yarns and formation of loops and snarls;

FIG. 3 is a characteristic diagram which shows relation between the twist coefficient and formation of loops and snarls;

FIG. 4 shows an embodiment of the steps of twisting rubbing additional twisting in the present in vention; and

FIGS. 5 and 6 are schematic views of examples of apparatus for the production of the bulked yarns in accordance with the present invention.

As is clear from FIG. 1. yarns of the lst grade have relatively small amount of loops and snarls and with the order of the 2nd grade, the 3rd grade and the 4th grade, degree of formation of loops and snarls gradually increases. Yarns of the 5th grade have considerably greater amount of loops and snarls and are the highest in bulkiness.

The yarns of said lst to 5th grades have spun yarnlike hand and excellent bulkiness, but those of the 2nd to 5th grades are especially preferred.

The yarns of below the lst grade have extremely low degree of loops and snarls and are inferior in spun yarn-like hand.

In the case of the yarns of higher than the 5th grade. the so-called neps are apt to partially occur to result in ununiform yarns.

The method of the present invention will be more detailedly explained below.

First of all, it is necessary to use combination of groups of plural yarns different in length by 3 to 40%, preferably 3 to 20%. The longer yarn is for producing loops and snarls in the bulked yarns. In this case, it is desirable requirement for obtaining bulked yarns having many uniform loops and snarls and excellent spun yarn-like hand to employ yarn consisting of many non or soft twisted filaments.

On the other hand, the shorter yarns constitute cores of bulked yarns and any kinds of yarns such as spun 3 yarns or filament yarns of natural, regenerated or synthetic fibers and furthermore, monofilament yarns, hard twist yarns, bulked and crimped yarns may be used. Kind of the yarns may be optionally determined depending upon end use of the bulked yarns to be produced.

The method for imparting the difference of 3 to 40% in length of yarns and the method for twisting the yarns in an optional direction are as follows:

The method for imparting difference in length.

l. Using a doubling machine, a doubling twister, a ring twister, a fancy twister or a covering twister capable of respectively adjusting feeding amount of yarns, a difference is positively given in length of two yarns and the two yarns are then twisted with or without doubling.

2. Yarns consisting of filaments different in heat shrinkage or yarns different in heat shrinkage are doubled and heat treated before or after twisting step to shrink to cause difference of 3 to 40% in length.

3. Difference in length of two yarns is given by the difference of feeding amount of two yarns and by the combination of two different yarns different in heat shrinkage. Due to these two factors, a difference of 3 to 40% is obtained in length of the yarns.

When difference in length is to be obtained by adjusting the feeding amount of the yarns as mentioned in (I), any combination of yarns may be employed if the longer yarn meets the necessary requirements. On the other hand, when difference in heat shrinkage is utilized, combination of yarns capable of resulting in difference of substantially 3 to 40% in length after heat treatment must be chosen. Examples of the combination of yarns in this case are those of highly shrinkable fibers capable of easily shrinking with heat such as polyamide, polyester, polyolefin, polyacryl fibers and their bicomponent fibers, and low shrinkable fibers of regenerated fibers such as viscose rayon, cupra fibers, etc. In the case of the same kind of synthetic fiber yarns, these-are rendered different in heat shrinkage by difference in drawing ratio, difference in viscosity and addition of a third component in production of yarns and thus obtained yarns are suitably combined. Furthermore, the combination of groups of plural yarns having different length may not necessarily comprises combination of two or more of same or different kind of yarns as mentioned above, but the bulked yarns may also be produced from two kinds of filaments different in heat shrinkage and simultaneously spun as a single yarn, or mixed yarns obtained by opening two kinds of yarns and mixing them. Therefore, groups of plural yarns" in the present invention also includes the latter two cases.

Next, an explanation will be given with reference to the requirement that a difference of 3 to 40% in length of yarns must be imparted to the yarns. As described before, difference in length of yarns is very important for formation of loops and snarls. The difference in length can be considered to be a latent requirement which determines size and amount of loops and snarls and the rubbing action in the post treatment is considered to be an acutallized requirement for forming loops and snarls. According to the inventors experiment, if the yarns have a difference in length of at least 3%, loops and snarls of about the 1st to 2nd grades can be formed by increasing the amount of rubbing at the post treatment, but when the difference in length is less than 3%, loops and snarls are only slightly formed and spun yarn-like bulked yarns intended by the present invention cannot be obtained.

When the yarns are doubled and twisted under the conditions that the difference in length exceeds 40%, neps are apt to be formed by rubbing and the loops and snarls of yarns become very ununiform. Therefore, in order to produce spun yarn-like bulked yarns having stable quality, it is necessary that difference in length of the starting yarns is 3 to 40%, preferably 3 to 20%.

The yarns to which the difference in length is positively and previously imparted under the conditions as mentioned above must be then twisted in a given amount to obtain cohesion property. However, when difference in length is imparted utilizing difference in heat shrinkage of yarns, the yarns may be previously twisted and then subjected to shrinking treatment to impart substantial difference in length. The number of twist may be determined depending upon the desired degree of loops and snarls, but generally it may be obtained in accordance with the following formula:

:1 r/ m wherein;

T The number of twist per meter at Twist coefficient Nm Metric count It has become clear by experiments that in the present invention, range of the twist coefficient a in said formula is 10 to 140, preferably 20 to 110. That is, when the twist coefficient is less than 10 in the present invention, cohesion property of yarns having difference in length is not in a preferred state and uniform loops and snarls are not formed in the longer yarn by the subsequent rubbing treatment and the loops and snarls are concentrated at a part of the yarns to cause formationn of neps. When the twist coefficient is more than 140, cohesion property becomes complete and filaments which constitute the longer yarn are not disassembled by rubbing to make it impossible to form spun yarn-like uniform loops and snarls.

It is essential that the yarns to which the differences in length has been imparted are twisted in a range of twist coefficient of 10 to 140. It is sufficient that the twist coefficient suffices said range immediately before the subsequent rubbing step. Therefore, the yarns to which the difference in length has been imparted and which has been twisted in a twist coefficient of 10 to may be subjected to rubbing at the subsequent step to develop loops and snarls. Alternatively, yarns to which the difference in length has been imparted and which have been twisted at an optional twist number and in an optional direction may be untwisted in a direction opposite to the direction of said twisting in such a manner that the untwist number is below the number of said twist to keep the remaining-twist coefficient of thus untwisted yarns at 10 to 140 and then the yarns may be subjected to rubbing to develop loops and snarls. Especially, in the latter case, rubbing is carried out simultaneously with untwisting. Therefore, rubbing action is extremely good and substantially no breakage of yarns occurs. Moreover, particularly uniform loops and snarls can be formed.

In the present invention, the yarns to which differ-' ence in length has been given and which are twisted as explained above are then rubbed to develop loops and snarls. This rubbing can be carried out with any materials which have a high abrasion resistance and do not damage the yarns (such material is called rubbing device" hereinafter). The rubbing causes separation of Tension after rubbing device (g) Amoum of rubbing Tension before rubbing device (g) In the present invention, amount of rubbing is suitably l.] to 20.0. Increase in the amount of rubbing more than required may damage the yarns. Furthermore, yarn tension before rubbing device is at least 3g, generally 3 to 40g and preferably 5 to lSg.

In the present invention, thus rubbed yarns must be additionally twisted in the same direction as the first twisting to set the loops and snarls formed by said rubbing. The number of the additional twist is preferably at least 5 in terms of twist coefficient. When this twist coefficient is smaller, the loops and snarls are moved due to a slight rubbing to cause formation of neps or ununiform loops and snarls.

As detailedly explained above, according to the present invention, spun yarn-like bulked yarns having loops and snarls of five grades as shown in photographs of FIG. I can be optionally produced depending upon the degree of difference in length imparted to the initial yarns, the number of twist and amount of rubbing.

It has been clarified by experiments that correlations between degree of loops and snarls generated and each of said three factors are as shown in FIGS. 2 and 3.

FIG. 2 shows the contribution of difference in length to generation of loops and snarls. Thatis, highly shrinkable polyester filament yarns (90 /48f) having a dry heat shrinkage of 36% at 180C and polyester textured yarns (75)24j) were used and degree of figuration of loops and snarls was observed when the difference in length and amount of rubbing were changed with number of twist kept at constant (70 in terms of twist coefficient). Numerals in the graph of FIG. 2 represent amount of rubbing. As is clear from this FIG. 2, degree of figuration of loops and snarls considerably varies depending upon difference in length of yarns and amount of rubbing. With increase in difference in length, amount of rubbing can be relatively decreased.

FIG. 3 shows the contribution of twist coefficient (which also corresponds to remaining-twist coefficient) to generation of loops and snarls. That is, the same yarns as used in FIG. 2 were used and degree of figuration of loops and snarls was observed when twist coefficient and amount of rubbing were changed with difference in length (R I8.7l%) kept constant. Numerals in the graph of FIG. 3 represent amount of rubbing as in FIG. 2. As is clear from the FIG. 3, degree of generation of loops and snarls considerably varies depending upon twist coefficient and amount of rubbing and especially, there is optimum range in twist coefficient depending upon the yarns used.

For better understanding of the present invention, a model diagram of twistingrubbing+additional twisting steps in the present invention is illustrated in FIG. 4. In FIG. 4, (a) shows the steps of twisting yarns having difference in length in an optional direction at a twist coefficient of ID to I40, then rubbing said yarns and additionally twisting in the same direction as the first twisting direction. In FIG. 4, (b) shows another embodiment of the steps of twisting the yarns having difference in length in an optional direction to a suitable extent, untwisting the twisted yarns in such a manner that remaining-twist coefficient is within the range of It) to I40, then rubbing the yarns and thereafter additionally twising the yarns in the same direction as the first twisting. In this case, amount of untwisting varies depending upon amount of the first twisting, but in the present invention it is sufficient that said yarns are twisted in such a degree as 10 to I40 in terms of twist coefficient immediately before the rubbing and thus the amount of untwisting has no special limitation. Therefore, such steps as shown in (c) in FIG. 4 may be employed.

In other words, the embodiment of (a) in FIG. 4 corresponds to the embodiments (b) and (0) wherein amount of untwisting is zero.

In the present invention, the twist indicated by dotted line in (b) and (c) in FIG. 4 is considered to be remaining twist and twist coefficient in this case is defined as remaining-twist coefficient.

Next, one example of the apparatus for carrying out the method of the present invention will be explained with reference to the drawings. In FIG. 5, yarns l to which a difference in length of 3 to 40% has been given and which have been twisted are set in a ring twister and a rubbing device 3 is provided between feed roller 2 of said ring twister and twisting part 4. By said rubbing device 3, the yarns are rubbed to form loops and snarls and subsequently the yarns are additionally twisted in the twisting part 4. In the case of using yarns which utilize difference in heat shrinkage, a heater is provided before or after the feed roller 2 to obtain a difference in length of 3 to 40%.

Another method for practicing the present invention is illustrated in FIG. 6. In FIG. 6, yarns 5 which comprise combination of two kinds of yarns different in heat shrinkage and which have been twisted in an optional direction are allowed to pass through heater 6 to shrink one kind of the yarns to impart a difference in length of substantially 3 to 40% and subsequently the yarns are allowed to pass through and contact with a cylindrical rotator which is rubbing device 7, whereby false twist and rubbing are imparted to the yarns. That is, a difference in length is imparted to substantially twisted yarns and then the yarns are continuously subjected to untwisting-*rubbingtwisting. When the method as shown in FIG. 6 is employed, rotating direction of the rubbing device must be determined so that the yarns are rotated in the direction of untwisting immediately before the first twisted yarns contact with the rubbing device. The number of twist when contacting with the rubbing device must be ID to I40 in terms of the remaining-twist coefficient. Furthermore, the yarns are relaxed between a pair of

rollers

8 and 9 before and after heater 6 and shrinking percentage of the yarns is determined by the velocity difference in

rollers

8 and 9, and moreover move of twists must be prevented by roller 9 between heater 6 and rubbing device 7. This is because if roller 9 is not provided, untwisting torque extends to the heater part to heat-set the twists to result in yarns having torque as in the usual false twisting.

In the case of using yarns which do not utilize heat shrinkage, there is no need to provide heater 6. This is the reason why the present invention is different from 7 the usual false twisting in the object and technical construction.

According to the method of the present invention as explained above, spun yarn-like bulked yarns having uniform loops and snarls and excellent in bulkiness can be economically and stably produced with use of extremely simple apparatus. Furthermore, soft and voluminous knitted fabrics having good warmth retainability is obtained by knitting the bulked yarns obtained by the pesent invention.

The present invention will be illustrated in the following Examples.

EXAMPLE l Highly shrinkable polyester filament yarns (75d/24f) having a dry heat shrinkage of 36% at 180C and polyester false twisted yarns (75d/24f) were twisted at S. 400T/M (twist coefficient a 50) in equal feeding amount by a ring twister. Then, with use of the apparatus as shown in FIG. 6 thus obtained twisted yarn was allowed to pass through a heater at 180C for 1 second with overfeeding of 20% to shrink the highly shrinkable polyester yarns to result in difference of 18.5% in length from the polyester false twisted yarns. At this time, the twisted yarn had a twist number of 480T/M due to the shrinking. Furthermore, said twisted yarn was allowed to pass through a rubbing device in the form of a hollow cylinder, inside of which was made of urethane rubber and which had an inside diameter of 25 mm, at a speeed of 400 m/min and was taken up by a take-up apparatus. Said rubbing device was rotated at 4,000 rpm and the yarn was allowed to contact with the rubbing device at a rubbing amount of 4.0 and a tension before rubbing device of 10 g. The number of twist at that time was about 8.400 T/M and the number of twist of the final bulked yarn was 8.483 T/M. Thus obtained bulked yarn was spun yarn-like soft yarn having loops and snarls which was graded as the th grade of (e) in FIG. 1. Furthermore, said bulked yarn was knitted into a fabric of Pont-de-Rome by a tubular knitting machine of 18 gauges to obtain ajersey having wool-like soft hand. Said bulked yarns were additionally twisted at S. l ,300 T/M and were arranged as warp and weft at a warp density of 39 yarns/cm and a weft density of 26 yarns/cm to weave a georgette crepe. This fabric had extremely irregular surface and bulkiness, but had markedly light hand and high elasticity.

EXAMPLE 2 Highly shrinkable polyester filament yarns (90 d/48f) having a dry heat shrinkage of 36% at 180C and cupra filament yarns (75d/45f) were twisted at 2.400 T/M (a 54) by a ring twister in an equal feeding amount. Then, using the apparatus as shown in FIG. 6, thus obtained twisted yarn was heat treated at 225C for about 0.l5 second with overfeeding by 20% into the heater to shrink the highly shrinkable polyester filament yarns, whereby a difference of substantially 20% in length of the highly shrinkable polyester filament yarns and the cupra filament yarns was obtained and the number of twist was 2.470 T/M. Subsequently, using the same rubbing device as used in Example 1, said twisted yarn was allowed to contact with said rubbing device rotated at 4,000 rpm at a yarn speed of 400 m/min, rubbing amount of 3.7 and tension before the rubbing device of g. At that time, the number of twist was about 2.420 T/M. The final number of twist of thus obtained bulked yarn was 2.470 T/M and filaments of cupra filament yarns were disintegrated (opened) with the polyester filament yarns as core to form loops and snarls which were of about the 4th grade of (d) in FIG. 1. A knitted fabric made of thus obtained bulked yarns was excellent in hygroscopicity, had smooth touch and was suitable as underwears and baby wears.

EXAMPLE 3 Wool yarns of 64 metric counts and polyester false twisted yarns of 100 d/36f were twisted at 2.350 T/M (a 56) by a ring twister with the feeding amount of said polyester false twisted yarns being greater by 10% than that of said wool. Thereafter, thus obtained twisted yarn was allowed to pass through the same apparatus as shown in FIG. 6 without the heater, contacting with the same rubbing device as in Example I rotating at 4,000 rpm at a yarn velocity of 400 m/min, a rubbing amount of 7.0 and a tension before rubbing device of 8g. At that time, the number of twist was 2.300 T/M. The final number of twist of thus obtained bulked yarn was 2.350 T/M and the polyester false twisted yarns were entangled with the wool as core. Thus obtained bulked yarn had high elasticity and were classified as the 4th grade of (d) in FIG. 1.

EXAMPLE 4 Polyester filament yarns of 75d/36f and Nylon 66 filament yarns of 70d/34fwere twisted at 8.300 T/M (a z 48) by a ring twister with the feeding amount of the nylon 66 filament yarns being larger by 6% than that of the polyester filament yarns. Then, thus obtained twisted yarn was allowed to pass contacting with the rubbing device provided in the ring twister as shown in FIG. 5 at a rubbing amount of 5.0 and a tension before rubbing device of 7g. Subsequently, the yarn was additionally twisted at 8.80 T/M to obtain a bulked yarn. Said bulked yarn had loops and snarls of about the 3rd grade of (c) in FIG. 1. Furthermore, said bulked yarn was knitted to obtain a graceful, tough and soft knitted fabric which resembled wool.

EXAMPLE 5 Polyester filament yarn of d/36fwas twined around a core yarn of the same kind of polyester filament yarn by a covering twister to impart difference in length between the two filament yarns. Thus obtained cove red yarn had a twist number of 2.500 T/M (a z 65) and a difference in length of 5% between the two filament yarns. Thus obtained covered yarn was allowed to pass contacting with the rubbing device provided in the ring twister as shown in FIG. 5 at a rubbing amount of 8.8 and a tension of 4g before rubbing device to rub the yarn. The yarn was then additionally twisted at 300 T/M in the direction of Z to obtain a bulked yarn of about the 2nd grade of (b) in FIG. 1.

What is claimed is:

l. A method for producing spun yarn-like bulked yarns which comprises twisting plural yarns having difference in length of 3 to 40% in an optional direction at a twist coefficient of I0 to I40, rubbing thus twisted yarns to form loops and snarls in longer filament yarns and subsequently additionally twisting the yarns in the direction of the first twisting so that the twist coefficient becomes at least 5 to set the loops and snarls formed by the rubbing action.

2. A method for producing spun yarn-like bulked yarn which comprises twisting plural yarns having differcnce of 3 to 40% in length to a suitable extent in an optional direction, then untwisting the twisted yarns in such a manner that the number of the untwisting is below the number of the first twisting and remainingtwist coefficient is within the range of 10 to I40, rubbing the yarns to form loops and snarls in longer filament yarns and subsequently additionally twisting the yarns in the direction of the first twisting so that the twist coefficient becomes at least 5 to set the loops and snarls formed by the rubbing action.

3. A method according to claim 2, wherein untwisting, rubbing and additional twisting are continuously carried out.

4. A method according to claim 1, wherein the difference in length of yarns is 3 to 5. A method according to claim 1, wherein the difference in length is imparted to the yarns by difference in feeding amount of the yarns.

6. A method according to claim 1, wherein the difference in length is imparted to the yarns by difference in heat shrinkage of the yarns.

7. A method according to claim 1, wherein the difference in length is imparted to the yarns by combination of difference in feeding amount and difference in heat shrinkage.

8. A method according to claim 1, wherein the twist coefficient of the first twisting is 20 to 110.

9. A method according to claim 1, wherein amount of rubbing defined in the specification is l.l to 20.0.

10. A method according to claim 1, wherein yarn tension before rubbing device is at least 3g.

11. A method according to claim I, wherein the plural yarns are combination of polyester filament yarns different in heat shrinking characteristics.

12. A method according to claim 1, wherein the plural yarns are combination of highly shrinkable syn thetic fibers and low shrinkable regenerated fibers.

Claims

1. A method for producing spun yarn-like bulked yarns which comprises twisting plural yarns having difference in length of 3 to 40% in an optional direction at a twist coefficient of 10 to 140, rubbing thus twisted yarns to form loops and snarls in longer filament yarns and subsequently additionally twisting the yarns in the direction of the first twisting so that the twist coefficient becomes at least 5 to set the loops and snarls formed by the rubbing action.

2. A method for producing spun yarn-like bulked yarn which comprises twisting plural yarns having difference of 3 to 40% in length to a suitable extent in an optional direction, then untwisting the twisted yarns in such a manner that the number of the untwisting is below the number of the first twisting and remaining-twist coefficient is within the range of 10 to 140, rubbing the yarns to form loops and snarls in longer filament yarns and subsequently additionally twisting the yarns in the direction of the first twisting so that the twist coefficient becomes at least 5 to set the loops and snarls formed by the rubbing action.

4. A method according to claim 1, wherein the difference in length of yarns is 3 to 20%.

5. A method according to claim 1, wherein the difference in length is imparted to the yarns by difference in feeding amount of the yarns.

9. A method according to claim 1, wherein amount of rubbing defined in the specification is 1.1 to 20.0.

11. A method according to claim 1, wherein the plural yarns are combination of polyester filament yarns different in heat shrinking characteristics.

12. A method according to claim 1, wherein the plural yarns are combination of highly shrinkable synthetic fibers and low shrinkable regenerated fibers.