US3495393A - Non- or low-stretch composite yarn of super high bulk - Google Patents

Description

Feb.17, 1970 I 1 v gsm) W METAL 3,495,393 7 non-on LOW-.STRETCB cpuPosI'rE YARN 0F sum: HIGH BULK Filed llarch 4., 1968 s Sheets-Sheet 2 OSA 'u on vpsmvmwfismp MASMKI mm BY I i s I ATTORNEYS Feb. 17,1970 QS w D ETAL 3,495,393 u NON-0R LOW-STRETCH couf'osnn YARN 0F SUPER HIGH BULK Filed March 4, 1968 Y 3 Sheets-Sheet IIIII ,OSM. WAINVENTQRQ; J M M fi'sms 84m 1mm Haul.

A'n'olwm United States Patent Int. Cl. D02 3/36 US. Cl. 57-144 11 Claims ABSTRACT OF THE DISCLOSURE Composite yarn, characterized by the fact that the core consists of non-stretch or low-stretch yarn around which a plurality of crimped polymer filaments are wrapped with each filament in a series of helical turns and in unusually bulged state so that a resulting composite yarn has both higher bulkiness and liveliness.

BACKGROUND OF THE INVENTION This invention relates to a. nonor low-stretch composite yarn of super high bulkiness, and a process of producing said composite yarn. As used herein the term inelastic yarn refers to any monoor multifilament yarn crimped or not of fibre except polyurethane and rubber, and spun yarn of the same fibre. For example such fibres include polyester fibre, polyamide fibre, polyacrylonitrile fibre, polyvinyl chloride fibre, polypropylene fibre, glass fibre, steel fibre. The term crimped yarn refers to any synthetic filament yarn crimped by the presently known process such as twisting and setting techniques, false twisting, stutfer box, or any other producer texturing.

The well known crimped yarn has a feature of soft feeling by which it has been advantageously and beneficially applied in some commercial field. But the inherent insufficiency of liveliness when fabricated in apparel form is now a problem precluding it from a wider application in commercial field for which a solution is continuously demanded. Any suitable liveliness of crimped yarn may be attained as desired by increasing its denier in successive steps to increasing degree of fineness, but contrary to this, as the liveliness increases, the soft feeling inherently possessed by the crimped yarn disadvantageously decreases. Furthermore, the crimped yarn has a defect such that the crimp cannot remain in bulky state due to excess tension throughout many steps of manufacturing process for fabricating.

The present invention is directed to a composite yarn in which a. majority of the liveliness is borne by the core and the soft feeling by the covering yarn mainly, so that a resulting yarn may have both liveliness and soft feeling.

SUMMARY OF THE INVENTION The present invention is characterized by the fact that the cover is tensioned and relaxed consecutively and immediately; both core and cover are gathered and finally twisted so that the cover is wrapped around the core with each, filament in a series of helical turns to form a nonstretch 0r low-stretch composite yarn of super high bulk; and that the cover is overfed relative to the core during the operation so that significant bulkiness can be obtained.

It is the most important object of the present invention to provide a non-stretch or low-stretch composite yarn having both super high bulkiness and suitable liveliness.

Another object of the invention is to provide a process of producing said composite yarn.

Patented Feb. 17, 1970 ICC Yet further objects and advantages of the invention will be apparent from the following description, the accompanying drawing and the appended claims.

FIGS. 1(a) and (b) are two schematic views taken on the opposite side of each other, greatly enlarged of yarn embodying the invention.

FIGS. 2 to 7 are schematic views illustrating various modified apparatuses for practicing the process of the invention.

Throughout the figures, similar numerals refer to similar parts of the apparatuses.

Referring now in detail to the drawing, a composite yarn is shown in FIG. 1, which yarn includes a core 1 around which a covering yarn is wrapped with each filament in a series of helical turns and in bulged state so that an unusual bulkiness in achieved. Any textile fibre available in staple or filament form may be used as a core yarn regardless of whether crimped or not. Such fibres include natural fibres such as cotton and wool, and synthetic fibres such as polyester fibre, nylon fibre, polyvinyl chloride fibre, and such mineral fibre as glass fibre and steel fibre. As for the covering yarn, any filament available in crimped form may be included and any operation by which the crimp is originally formed may be applied such as the texturing, stutfer box, gear crimping, torque crimping, edge crimping, or any other crimping process. The use of each filament of the core in a denier not less than twice that of the cover filament has been found beneficial in achieving the yarn. The election of fineness of the core filament has been found beneficial in limiting it in denier from 4 to 20.

Any synthetic yarn available in crimped form may be used as the cover filament, and election of fineness of the filament is found suitable in limiting it in a denier less than 5.

The foregoing limitations of fineness for the core and cover filament are most critical to make a resulting yarn gain the intended liveliness mainly by the core and a majority of the soft feeling by the cover. When the critical factors of fineness of both core and cover are controlled within the limits, the composite yarn resulting from the practice of this invention has both higher bulkiness and liveliness, provided that the final twist and the rate of the cover overfeed are suitably and reasonably regulated as the case requires. For example, it is found that when each filament of the core yarn is in a denier less than 4 or more than 20, the intended liveliness can not be expected. It is also found that when the filament of the cover is in a denier more than 5, the intended soft feeling cannot be expected. The cover filaments are longer by about 10 to 200% preferably from 10 to 50% than that of the core in the unit length of the resulting composite yarn so that the cover is facilitated to cover the core. IIf the excess of cover length falls below 10% relative to the core length in the unit length of the resulting yarn, covering throughout the full length of the core is found insufficient, or if it falls above 200% the sheath formed by the covering yarn is also found loosened and appearance injured to such a degree as not commercially applicable. Limitation of that excess is beneficially controlled in the range of from 10 to 50% relative to the core. Crimped yarns made by twisting and setting techniques may be advantageously used as a core to preclude the cover from sliding thereon and bulkiness can be additionally obtained by the core. The use of 2 to 3 filaments with each filament in a denier from 10 to 20, has been found best in bringing about liveliness, and the use of core in total denier from 50 to and cover in total denier 75 to is best for bulkiness.

It is to be noted that the length of the core and cover is measured under reasonable tension Within the tolerance recognized in the trade.

Referring now to FIG. 2, there is shown an apparatus for producing a composite yarn in accordance with this invention by twisting method. A core yarn 1 advances through a pair of nip rolls 3 from any package not illustrated and the covering yarn 2 advances from also any package not illustrated, through the back pair of drafting rolls 4, and thence through intermedaite pair of rolls 5 to the front pair of rolls 6. The linear speed of the intermediate pair of rolls 5 is greater than that of the back pair of rolls 4 so that covering yarn is tensioned when passing the zone defined by the back pair and intermediate pair. The tension load falls within the range of from 0.5 to 2.5 gram per denier wherein the elongation falls generally within the range of from 1.5 to 12% relative to the original length. The covering yarn 2 advances in at an angle to the core axis at a faster speed than that of the core yarn to facilitate wrapping the cover therearound. The core and cover pass together through a snail wire 7, a ring traveller 9 and then are wrapped around the bobbin 10 to form a package 11 thereon. The core and cover are finally twisted together and cover 2 is twisted therearound by rotating the bobbin through a driven pully mounted on the spindle not illustrated. The ring traveller 9 is slidably mounted for rotation on a vertically movable ring rail so that the ring traveller can move up and down with relation to the bobbin 10 to build up a package 11 thereon. Twist in turns per meter from 50 to 1500 is applied to the composite yarn. It has been found that if the number of turns falls below 50 per meter, the cover slides and above 1500 the soft feeling decreases. The rotational speed of the front pair of rolls 6 is less than that of the intermediate pair of rolls 5 so that the cover passed from the intermediate pair is immediately relaxed in overfed state. This makes the cover yarn outwardly bulged with each filament in dispersed state so that the achieved bulkiness is significantly higher than that expectable from an inherent one. It should be noted that this phenomenon is ingeniously applied to the present invention to obtain unusually higher bulkiness.

The linear speed of the front pair of rollers 6 is reasonably less than that of the intermediate pair of rolls 5, so that each of the covering filaments may be permitted to be bulged outwardly to present a significantly higher bulkiness. By slackening immediately after the tensioning, each filament of the covering yarn disperses to achieve a higher bulged state than that expectable from an inherent one.

It is understood that the unusually higher bulkiness of the cover yarn is achieved by development of the inherent bulkiness and additional strain by a stress experienced when the tensioning is performed. While pairs of rollers have been illustrated and described as a device for producing high bulkiness, it will be found that any tension device may be used in place of roller devices, and the distance between the front pair of rolls 6 and the covering point may be changed as the condition may require. For example, the front pair of rolls 6 may be arranged extremely adjacent to the covering point. It is found that omission of the front pair of rolls may be beneficially permitted for the purpose of simplifying the apparatus only.

In FIG. 3, is shown another type of apparatus for practicing this invention, in which the front pair of rolls 6 additionally operates as a core feeding pair of rolls, and accurate doubling or gathering of two yarns can be achieved. It is further found that the location of the core can be defined accurately near the axis of the cover at the nip of the front pair during the process. This prevents the core yarn from being displaced from the center of the resulting yarn to the outside of the yarn.

It should be noted that the process does not necessarily require twisting immediately after the performance of the relaxing and gathering procedures.

The apparatus in FIG. 4 shows the foregoing apparatus in which the twisting is separately performed late after the core and cover have been doubled. The process practiced in such manner has been found beneficial in preventing the crimped cover yarn from being tensioned when the cover is unwound from package for final twisting, since a majority of the unwinding load is borne by the core yarn 1. Also it is found that when the yarn 1 and 111 are unwound from the package on bobbin 110, it is beneficial to brake the yarn at the let-off position for preventing the core and cover from being separated from each other during the unwinding. The apparatus B in FIG. 4 differs from apparatus A in the manner in which the front pair of feed rollers is used for feeding not only the cover but the core in order to achieve accurate maintenance of the core in center axis of the cover during the process.

Now referring to FIG. 5, there is shown modified apparatus to produce the yarn of this invention. In this apparatus two core yarns are separately fed and the covering yarn enters the doubling and twisting point so that the rate of over feed of the cover may be advantageously increased, even though a smooth monofilament yarn is used as core. For example, when the two monofilament yarns of polyethylene terephthalate are used as said two core yarns and crimped filaments of the same material are used as cover, the rate of the over feed of 10% can be easily obtained, while the 10% rate is found to be the difficult upper limit when the two monofilaments are previously doubled and twisted prior to this operation.

Further for this purpose, the covering yarn may not be gathered only at the doubling point of the core yarns, but at any point on one of the core yarns from the gathering point to feed roll 3. In the latter case the covering yarn is preferably wrapped around the core yarn by the action of torque of the core yarn transmitted from the doubling point.

Referring now to FIG. 6, there is shown another modified apparatus to practice the process of this invention. In the apparatus the bottom roller 3' of the feed rolls dips its lower portion into any adhesive agent in a tank 3", so that the core may be wetted with the agent when it passes through the nip of the feed rolls. Such manner of operation has been found beneficial in lessening the number of twist turns in unit length of the resulting yarn and in preventing the cover from sliding on the core. Further it is found that any material having a low melting temperature, may be advantageously used together with the core yarn so that adhesion may be effected between the core and cover by heating prior to the gathering.

Referring now to FIG. 7, there is shown a further modified apparatus for practicing the process of this invention. In the apparatus, a pair of fluted rolls are used as a pair of feed rolls so that the core is crimped and slippage of the cover can be prevented during the twisting operation.

One of the most preferred embodiments of this invention is a process for preparing a low stretch high-bulk yarn, characterized in that there are used a crimped bulky multi-filament yarn as the cover in which the individual filaments are dispersed and which is obtained by twisting in the S direction (or Z direction) heat-setting and untwisting and a crimped multi-filament yarn as the core having a mono-filament denier twice or more as large as that of the first-mentioned yarn and obtained by twisting in the opposite direction, namely, Z (or S) direction, heat-setting and untwisting, the length of the former yarn being 10-200% larger than the latter; the former yarn is positioned on the surrounding portion and the latter yarn, at the center; and that they are imparted a twist of 501500 turns per meter in the same direction as that of twisting of the latter yarn, namely, Z (or 5) direction. A composite yarn obtained according to this process is bulky and exhibits liveliness because a torque crimped yarn having thick monofilaments is used as a core. It also possesses a soft feel because of the use of a torque crimped yarn having thin monofilaments as a covering yarn. When the core is wrapped by covering yarn and twisted, the covering yarn is twisted in the direction opposite to that employed when originally preparing the covering yarn, and consequently the resulting yarn is more bulky. The core yarn having substantially a larger torque than the covering yarn, when twisted together with the covering yarn, is twisted in the direction of twisting the core yarn, namely in the direction of less torque. Thus, a yarn having low torque is obtained.

Another of the most preferred embodiments of this invention is a process for preparing a low stretch highbulk yarn, characterized in that there are used a crimped bulky multi-filament yarn as the cover in which the individual filaments are dispersed and which is obtained by twisting, in the S direction (or Z direction) heat-setting and untwisting and a crimped multi-filament yarn as the core having a monofilament denier twist or more as large as that of the first-mentioned yarn and having the number of monofilaments less than A1 of those of the firstmentioned yarn, which is obtained by twisting in the opposite direction, namely, Z (or S) direction, heat-setting and untwisting, the length of the former yarn being -200% larger than the latter; the former yarn is positioned on the surrounding portion and the latter, at the center; and that they are imparted a twist of 50-1500 turns per meter in the opposite direction to that of twisting of the latter yarn, namely, S (or Z) direction. When the core yarn is wrapped by covering yarn and twisted according to this process, the twist is imparted in the direction opposite to that of twisting the core yarn with a purpose of overtwisting the core yarn. Then the core yarn becomes very bulky, and it is possible to obtain a bulky composite yarn.

EXAMPLE 1 A 45-denier/3-filament false twisted polyester yarn (Z torque) was used as core yarn, and covered with a 100- denier/48-filament false-twisted polyester yarn (Z torque). With an apparatus in FIG. 3, prior to covering the covering yarn had been widened to a width of about 7 mm. in a direction at right angle to the yarn axis by elongating it by 5% and relaxing it to put it under no tension. The covering yarn was over-fed by 3% relative to the core yarn, and the core yarn was fed into the center portion of the covering yarn. Alow stretch super highbulk yarn was obtained by imparting them a final twist of 600 turns per meter in the Z direction. Two of such low stretch super high bulky yarns were doubled, and imparted a final twist of 480 turns per meter in the S direction to make a material for woven fabric.

A woven fabric of a matt weave was prepared from the said yarn, and subjected to an ordinary finishing process such as scouring, relaxing, heat-setting, dyeing and again heat-setting. It exhited the properties as shown in the following table. For the sake of comparison, a woven fabric was prepared from ordinary false-twisted yarns by using the same technique both in weaving and in finishing. The said ordinary false-twisted yarn was prepared by imparting a twist of 200 turns per meter in the Z direction to a 150-denier/48-filanient (Z torque) polyester yarn, and imparting a final twist of 160 turns per meter in the S direction to two of such polyester yarns doubled.

RESULT OF TESTING OF WOVEN FABRICS Woven fabric prepared from The bending stiffness and bending recovery were measured in accordance with the description of Journal of Textile Institute, 1964, vol. 55, T516.

As can be seen from the above results, the woven fabric from the yarns of the present invention is very rich in bulkiness, and excellent in liveliness. It is impossible to give a definite measured value to the liveliness since the liveliness is of a sensuous amount. It is generally said however that the liveliness is excellent when the bending stifiness is appropriate and the bending recovery is good. Incidentally, the woven fabric according to the present invention was far more soft and excellent hand than the woven fabric prepared from the ordinary false-twisted yarns.

EXAMPLE 2 A Z torque -denier/8-filament false-twisted polyester yarn was used as a core. Using the apparatus in FIG. 2, an S torque -denier/48-filament false-twisted polyester yarn was over-fed by 20% relative to the core yarn in the same manner as Example 1, and a twist of 300 turns per meter was given in the Z direction. Thus, a low stretch high bulk yarn was obtained which had a very low torque, balance being maintained by the sum of Z torque of the core yarn, S torque of the covering yarn and S torque generated at the time of twisting.

EXAMPLE 3 A 40-denier/2-filament polyester yarn was used as a core yarn. Using the apparatus in FIG. 5, a 75-denier/36- filament false-twisted polyamide yarn having a triangular cross section as a covering yarn was over-fed by 30% relative to the core yarn, and a twist of 200 turns per meter was given. Thus, a non-stretch high bulk yarn was obtained. Prior to covering, the covering yarn had been elongated by 10%, and relaxed to put it under no tension. The covering yarn was fed into a point where two core yarns intersect each other. They were twisted together while part of the covering yarn is being held between two core yarns, and were associated tightly into a covered yarn. The obtained yarn was rich in bulkiness, and has a soft feeling and unique luster. It was suitable as a material for woven fabrics.

EXAMPLE 4 Using the apparatus in FIG. 4, a low stretch high bulk yarn was prepared in the same manner as in Example 1 using a 75-denier/15-filament false-twisted yarn as a core and a 100-denier/36-filament side-by-side type conjugate filament yarn composed of a polyethylene terephthalate resin and a polyethylene naphthalate resin as a cover.

EXAMPLE 5 A spun yarn of 64S (metric count) from cut staples of polyethylene terephthalate (4d, 76 mm.) was used as a core, and a false-twisted -denier/48-filament polyethylene terephthalate was used as a covering yarn. Using the apparatus in FIG. 6, powder of polyethylene terephthalate with which 35 mole percent of isophthalic acid had been copolymerized was added to the surface of the core yarn, and was fed to the covering yarn which had been over-fed by 70% relative to the core. A non-stretch high bulk yarn was obtained by covering in the same manner Woven fabric prepared from the yarns of the ordinary the present false-twisted Direction Unit invention yarns arpends/ineh 74 74 Weft Picks/inch. 72 72 Thickness. Mm. 0. 51 0. 46

Bulkiness Cmfi/g 2.6 1.9 Bending stifiness- Warp. G.-em. /cm 29.0)(10- 21.8X10- Bending recovery Weft Percent 90.0 83 2 as in Example 1. The twist imparted at this time was 300 turns per meter. The obtained yarn was dry heat-treated at 200 C, and coalesced points were developed partiy on the core and covering yarns.

While several embodiments of this invention have been illustrated and described herein, it will be apparent that modification thereof may be made without departing from the scope of the invention.

What is claimed:

1. A composite yarn which is non-stretch or low stretch and having super high bulkiness, said yarn comprising at least a core yarn and at least a covering yarn; said core yarn including at least an inelastic filament, said covering yarn consisting of a plurality of crimped filaments surrounding the core with each filament in a series of helical turns and in a dispersed state, the denier of singie filament of the core yarn being at least twice that of a single filament of the covering yarn.

2. The composite yarn of claim 1 wherein one filament of the core has a denier from 4 to 20 and one filament of the cover has a denier less than 5.

3. The composite yarn of claim 1 wherein the length of the cover filament is larger by from 10 to 200% than that of the core filament in the unit length of the resulting yarn so that the core is well covered by the covering yarn.

4. The composite yarn of claim 1 wherein the final twist in turns is in the range of from 50 to 1500 per meter.

5. The composite yarn of claim 1 wherein the core consists of crimped filaments made by twisting and heatsetting techniques.

6. The composite yarn of claim 1 wherein the core consists of a plurality of filaments with each filament having a denier from 4 to 20 and the cover consists of a plurality of crimped filaments with each filament having a denier less than 5, and the length of the cover is from 10 to 50% larger than that of the core in the unit length of the resulting yarn.

The composite yarn of claim 6 wherein the core consists of from two to three crimped filaments with each filament having denier from 4 to 20, and the cover consists of a plurality of crimped filaments with each filament having a denier less than 5; and the length of the cover is from to 50% larger than that of the core so that the cover may be wrapped around the core.

8. The composite yarn of high bulk of claim 6 wherein the core has a total denier from 50 to 100 and the cover has a total denier from 75 to 150, the total denier of the cover being larger than the total denier of the core.

9. The composite yarn of claim 6 wherein the core yarn and cover yarn consist of a plurality of crimped filaments originally produced by twisting and setting techniques, the original twists of said filaments being in opposite directions to each other, the length of the cover relative to the core being greater by an amount of from 10 to 200%, the core filament being larger than that of the cover filament, and the final twist being in the same direction as that of the original twist of the core and in the range of -1500 turns per meter.

10. The composite yarn of claim 6 wherein both core yarn and cover yarii consist of a plurality of crimped filaments originally produced by twisting and setting techniques; the directions of the original twisting {being in opposite directions to each other, the length of the cover relative to the core being greater by an amount of from 10 to 200%; the core filament being more than twice as iarge as the cover filament, and the final twist being in the same direction as that of the original twist of the cover and in the range of 5 0-15 00 turns per meter.

11. A fabric containing non-stretch composite yarns of super high bulk, said composite yarns comprising at least a core yarn and at least a covering yarn, said core yarn including at least an inelastic filament, said covering yarn consisting of a plurality of crimped filaments surrounding the core with each filament in a series of helical turns and in a dispersed state, the denier of a single filament of the core yarn being at least twice that of a single filament of the covering yarn.

References Cited UNITED STATES PATENTS 1,840,156 1/1932 Carroil H 57-144 2,468,304 4/ 1949 Musselman 57-144 XR 3,387,450 6/1968 Brown 57-144 XR 3,401,516 9/1968 Chidgey et al 57l44 XR 3,410,078 11/1968 Freedman et al. r- 57-144 DONALD E. WATKINS, Primary Examiner US. Cl. X.R.

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