US3656214A

US3656214A - Crimping apparatus for manufacturing a bulky yarn

Info

Publication number: US3656214A
Application number: US4827A
Authority: US
Inventors: Goro Ozaw; Kenzo Kosaka; Kiyoshi Adachi; Tsutomu Okaya; Takeo Ariki
Original assignee: Mitsubishi Rayon Co Ltd
Current assignee: Mitsubishi Rayon Co Ltd
Priority date: 1969-08-26
Filing date: 1970-01-22
Publication date: 1972-04-18
Anticipated expiration: 1989-04-18
Also published as: JPS499430B1; FR2043408A5; DE2065062B2; DE2020764A1; GB1270606A; DE2065062A1; DE2065062C3; DE2065061A1; CH512601A; CS186705B2

Abstract

An air-jet type crimping apparatus equipped with a fiber ejection nozzle of an increased thermal effect, a rotational crimping member having a surface on which are peripherally arranged needle or honey-combed protuberances defining a multiplicity of spaces receptive of the fibers ejected by the nozzle composing the yarn and cone-type means for taking up the yarn from the surface at speeds automatically adjusted according to variations in the thermal shrinkability of the processed fibers. Fiber cooling means may advantageously be added for enhanced stability of the crimps imparted to the fibers.

Description

United States Patent Ozaw et al. [451 Apr. 18, 1972 [54] CRIMPING APPARATUS FOR 3,143,784 8/1964 Scott ..28/1.4 x MANUFACTURI A BULKY A 3,217,386 11/1965 Clendening.... ..28/ 1.4 X 3,251,181 5/1966 Breen et al..... .....28/72.l2 X [72] inventors: Goro 0zaw; Kenz Kosaka; Kiyoshl 3,255,508 6/1966 Weiss et al ..28/1.4

Adachi; Tsutomu Okaya; Takeo Ariki, all of Nagoya-shi, Japan Primary Examiner-Louis K. Rimrodt [73] Assign: Mitsubishi Rayon Company Limited, AttorneyRobert E. Burns and Emmanuel]. Lobato Japan 57 ABSTRACT [22] med: 1970 An airjet type crimping apparatus equipped with a fiber ejec- [2]] Appl. No.: 4,827 tion nozzle of an increased thermal effect, a rotational crimping member having a surface on which are peripherally arranged needle or honey-combed protuberances defining a [30] Fomgn Apphcauon Pnomy Data multiplicity of spaces receptive of the fibers ejected by the Aug. 26, 1969 Japan ..44/67084 n zzl mp ing he y n an cone-type means for taking up the yarn from the surface at speeds automatically adjusted ac- [52] us. C1 ..28/1.4 r i g o v ri ion in the thermal shrinkability of the [51] Int. Cl ,|)02 1/16 processed fibers. Fiber cooling means may advantageously be [58] Field of Search ..28/1.4, 72.12, 75 added for enhanced stability of the crrimps imparted to the fibers. [56] References Cited UNITED STATES PATENTS 8 Claims, 6 Drawing Figures 2,067,251 l/ 193 7 Taylor .2 8/ 72 ,12 X

PATENTEDAFR 18 I972 SHEET 1 OF 3 ATTORNEY PATENTEDAPR 18 N37? SHEET 2 [IF 3 The present invention relates to an improved crimping apparatus for manufacturing a bulky yarn, and more particularly relates to an improved apparatus for imparting crimps to thermoplastic filamentary fibers by ejecting, together with a heating medium, the heated filamentary fibers onto a rotationaltype crimping member.

Conventionally, manufacturing of bulky yarns is generally performed utilizing a false-twisting system, a stuffing-box system or an ainjet-ejection system. However, most of the conventional systems have shortcomings in the actual use thereof in manufacturing processes because of their mechanical design complexity, operational technique difficulties, because they dont provide sufficient freedom in the selection of the crimp shape to be imparted to the processed filamentary fibers.

In order to improve the above-described disadvantages, a novel crimping apparatus of a jet-ejection type has already been proposed regarding the manufacturing of desirable quality bulky yarns. In the case of this proposed technique, a yarn composed of thermoplastic filamentary fibers is ejected against a crimping member together with a heating medium flow for mutual fiber entanglement and heat setting. The

. crimping member is designed in the form of a rotational cylinder peripherally provided with a brush, needle or porcupine-type surface.

Since the original invention of the above-described type crimping apparatus, several improvements have been added thereto and even large fineness yarn crimp impartation for use in carpets became possible due to accumulation of such improvements. This was quite difficult in the case of another crimping technique. Especially, in case the processed yarn was composed of polypropylene fibers, it was difficult to provide the yarn with crimps of a desirable and stable nature, because the polypropylene fiber has a relatively large polymer crystallinity and the terminal groups thereof are not provided with a chemically or thermally reactive nature. Although employment of the above-described improvements enabled desirable crimp impartation even to such polypropylene fibers of the jet-ejection type crimping system, still no satisfactory operational function can be assured by the mechanical features of the conventional jet-ejection type crimping apparatus.

ln the case of the conventional crimping apparatus, a continuous yarn is introduced into an ejection nozzle together with a suitable heating medium such as heated air or steam, heated through contact with the heated medium while passing through the ejection nozzle and ejected against a barrier, which is located facing an outlet of the ejection nozzle in a spaced relationship, for crimp impartation. Generally, the e 'ection nozzle is composed of a yarn guide tube and a yarn e ection tube consolidated with the yarn guide tube in a mutually superposed relationship. A yarn ejection tube outlet is located downstream of a yarn guide tube outlet in an adequately spaced relationship and the processed yarn is heated within the space between the two outlets by the heating medium introduced therein. 80, provided that the heating medium temperature and type are once settled, the heating medium thermal effect on the processed fibers is apparently dependent upon the distance between the two outlets.

In case the referred distance is short, the effective fiber heating time becomes considerably short when the yarn is processed at a high speed, that is, the thermal effect on the processed fibers is lowered. Therefore, it becomes necessary to desirably and effectively impart crimps to such yarns of less heat reactive fibers such as a polypropylene yarn of relatively large fineness.

When the distance is elongated, there may be a lowering in the sucking effect on the processed yarn by ejection of the heated medium. So, in the initial introduction of the yarn through the ejection nozzle, it becomes necessary to cease the heated medium supply into the space for a smooth yarn passing or to use an adequate yarn guide hook or the like.

Further, the processed yarn tends to vibrate while advancing through the lengthened space and such yarn vibration forms a bar in the high speed crimping operation.

Still another disadvantage of the conventional crimping apparatus exists in the unstable removal of the fibers from the rotational cylinder type crimping member. After being ejected onto the crimping members peripheral surface, the processed fibers are allowed to stay within the spaces formed on the surface due to the presence of needles or like members. The length of this stay time varies as the shrinkability of the processed fibers varies, that is, the location of fiber removal from the surface also tends to vary. Perhaps this variation in the fibers removal point can be compensated for by adjusting the crimped fibers take-up speed, accordingly. However, this kind of speed adjustment is quite difficult to carry out in the actual production process.

When the actual fibers removal point deviates from the optimumly designed removal point, resistance against smooth fiber removal from the crimping members surface increases. This resistance increase leads to undesirable formation of fluffs or loops on the resultant yarn, breakage of the needles or like members due to excessive yarn tension or yarn breakages caused by irregular fiber removal. Such drawbacks will be further increased in the case of a high speed crimping operation. Therefore, an effective variation control in the abovedescribed fiber removal point is a key factor in achieving the high speed crimping operation, that is, enhancement of the systems productivity.

A principal object of the present invention is to provide an improved crimping apparatus capable of assuring a considerable production increase.-r""

Another object of the present invention is to provide an improved crimping apparatus capable of eliminating operational drawbacks encountered in the prior arts.

Still another object of the present invention is to provide an improved crimping apparatus producible of bulky yarns having crimps of desirable properties.

A further object of the present invention is to provide an improved crimping apparatus capable of imparting stable crimps to the processed fibers.

A further object of the present invention is to provide an improved crimping apparatus of simple mechanical design.

In order to attain the above-described objects, the apparatus of the present invention is provided with a pair of feed rollers, an ejection nozzle located downstream of the feed rollers, a rotational crimping member disposed relative to the ejection nozzle and provided with numerous superficial spaces formed by needles or protuberances and a particularly designed yarn take-up means for removing the yarn from the crimping members surface. The ejection nozzle is provided with a supplementary heating medium path encircling a main heating tube for sufficient heating of the processed fibers. The rotational crimping members peripheral surface is receptive of the fibers ejected from the ejection nozzle outlet. The yarn take-up means is generally in the form of a pair of cooperating substantially conical rollers. A contact line of the rollers is directed perpendicularly to the crimping member's rotational axis and the rollers large-diametral ends are directed toward the crimping members rotational direction. The yarn take-up speed can be automatically adjusted in response to the variation in the processed fibers shrinkability.

For better stability of the crimps imparted to the fibers, the apparatus of the present invention may advantageously be provided with fiber-cooling means and is located in the vicinity of the fibers removal point from the rotational crimping member.

Using the apparatus of the present invention, a considerably high speed crimping operation can be assured. For example, even a polypropylene yarn of 1850 denier thickness can be processed at a speedup to 250 m/min and a nylon yarn of 1,260 denier thickness, which has an excellent conformity to heat setting, can be processed at a speed up to 350 m/min. In case of a polyester yarn, it can be processed at a speed slower than the case of nylon yarn but faster than polypropylene.

Other features and advantages of the present invention will be more fully introduced in the following descriptions, reference being made to the accompanying drawings, in which;

FIG. 1 is an explanatory side view of an embodiment of a crimping apparatus according to the present invention,

FIG. 2 is a lengthwise cross-sectional view of an embodiment of the ejection nozzle used in the crimping apparatus of the present invention,

FIG. 3 is a side view partly in section a of the ejection nozzle shown in FIG. 2 for illustrating a switching operation.

FIG. 4 is a cross-sectional view of conduits for supplying the heating medium to individual ejection nozzles,

FIG. 5 is an explanatory side view of yarn take-up means used in the apparatus of the present invention,

FIG. 6 is a perspective view of an embodiment of the crimping apparatus of the present invention equipped with fibercooling means.

In a fundamental embodiment of the apparatus of the present invention shown in FIG. 1, a pair of

feed rollers

2a and 2b are located downstream of a given supply source (not shown) of a multifilament yarn 1. Located downstream of the

feed rollers

20 and 2b, is a cylindrical-type rotational crimping member 5 which rotates in a direction shown by an arrow in the drawing. A peripheral surface of the crimping member 5 is is provided with numerous spaces 5b formed by numerous needle-like protuberances 5a planted thereon. At a position downstream of the

feed rollers

2a and 2b, a fiber ejection nozzle 3 is disposed with its ejection outlet closely directing the peripheral surface of the crimping member 5. The ejection nozzle 3 is supplied with a compressed heating medium flow 4 from a given supply source (not shown). Located in the vicinity of the fibers planed removal point, is a pair of cooperative substantially

conical delivery rollers

6a and 6b, whose mechanical design will be hereinafter explained in detail.

In the above-described mechanical design of the apparatus of the present invention, the multifilament yarn 1, from the given supply source, is fed into the ejection nozzle 3 at a constant speed by the pair of

feed rollers

2a and 2b. Passing through the ejection nozzle 3, the multifilament yarn 1 is accompanied with the heating medium 4, under pressure, for example steam, also introduced thereinto and ejected through the ejection outlet of the ejection nozzle 3 and together with the heating medium, onto the peripheral surface of the crimping member 5. Due to the ejection under pressure, fibers in the multifilament yarn l are pushed into the spaces 5b on the surface and crimped therein and carried toward the removal point as the crimping member 5 rotates. Arriving at the removal point, the fibers in the multifilament yarn 1 are removed or take off from the surface by the conical delivery rollers 60 and 6b and taken-up by a suitable winder (not shown).

As is already briefly mentioned, the apparatus of the present invention is firstly characterized in the mechanical design of the fiber ejection nozzle 3. The fundamental requirements for the functional feature of the fiber ejection nozzle 3 are (a) suf' ficient thermal effect on the processed fibers even at a high speed, (b) less damage to the fibers and (c) fewer troubles in the operation and handling thereof.

Reiterating the former description, none of the conventional ejection nozzles can fulfill the above-described requirement without discrepancy.

Referring to FIG. 2, a typical embodiment of the fiber ejection nozzle favourably used in the apparatus of the present invention is shown. The ejection nozzle 3 comprises a yarn guide tube8 having a central longitudinal bore receptive of the yarn l to be processed and an ejection tube 7 adjustably threaded into the yarn guide tube 8 at its upstream end. As is shown in the drawing, the yarn guide path 8a of the yarn guide tube 8 elongates into a central longitudinal bore of the ejection tube 7. Through the central longitudinal bore of the ejection tube 7, a centrally bored main heating tube 9 extends in an annularly spaced relationship to the ejection tube 7. This annular space forms a supplementary space 11 for a heating medium path. A downstream end of the main heating tube 9 is connected to the downstream end of the ejection tube 7 and forms an ejection outlet of the fiber ejection nozzle 3. An upstream end of the main heating tube 9 meets the elongated yarn guide path 8a of the yarn guide tube 8 in an annularly spaced relationship. The central bore of the main heating tube 9 is connected with the supplementary heating medium in the annular space 11 by a connecting space 12 and a connecting path 13. The supplementary heating medium space 11 is connected to a given source (not shown) of the heating medium 4 by a supply conduit 10. The positional relationship between the ejection tube 7 and the yarn guide tube 8 can be changed as desired by adjusting the thread 14 connection.

The multifilament yarn 1 to be processed, is introduced into the yarn guide tube 8 as shown by an arrow. At this introduction, the yarn l is effected by a suction force presented by a heating medium 4, under pressure introduced into the fiber ejection nozzle 3 through the supply conduit 10. Coming into the central bore of the main heating tube 9, the yarn l is accompanied with the compressed heating medium 4 also introduced thereinto through the paths l2 and 13 and is heated. Together with this direct heating effect, the processed yarn l is additionally and indirectly heated by the heating medium 4 introduced into the supplementary heating medium space 11. Thus, the effective length of the heating zone can be elongated and the presence of the centrally bored main heating tube 9 assures effective prevention of the fibers disturbance during processing through the ejection tube 3. Although the major fibers disturbing effect is prevented, the direct contact of the compressed heating medium 4 with the processed yarn -1 within the main heating tube 9 brings about a moderate and desirable entangling action on the fibers composing the yarn 1 and, due to this fiber entangling effect, the fibers in the yarn are brought into an increased bundled condition.

Being ejected through the ejection outlet of the ejection tube 7, the fibers in the multifilament yarn l are deposited onto the peripheral surface of the crimping member 5 and are, due to the ejection force, pushed into the numerous spaces 5b formed on the surface for a physical deformation in a heated condition, that is, for crimping.

The shape of the crimps acquired on the fibers in the abovedescribed technique is quite distinctive in that the individual fibers are favourably entangled with each other and that the formed crimps are randomly distributed over the fibers composing the yam. This is fundamentally different from the crimp shapes obtained by the application of the conventional crimping techniques such as the false-twisting system of conventional stuffing box system. Namely, individual fibers are provided with smooth three-dimensional curves. Because of the above-described distictively shaped crimps, the resultant multifilament yarn can be provided with an enriched bulkiness and a soft hand feeling. When multifilament yarns of this type are used for manufacturing a tufted carpet, the desired product can be obtained by using a lesser yarn quantity when compared with yarns manufactured by another method.

The

feed rollers

2a and 2b may be constructed in the form of ordinary rollers or in the form of conical rollers as shown in FIG. 6, the latter assuring effective yarn supply speed control. In this case, the nip point selection of the yarn l by the pair of

conical rollers

20 and 2b can be carried out as desired by using an adequate yarn guide (not shown) and, when the nip point is selected on the larger diametral portion of the

rollers

2a and 2b, the yarn 1 will be supplied to the ejection nozzle 3 at a higher supply speed. Thus, the supply speed of the yarn l to the ejection nozzle 3 can be changed as desired by displacing the yarn guide along the contact line of the pair of

feed rollers

2a and 2b, accordingly.

During the manufacturing operation of the crimped yarn, there are some cases when the ejection of the heating medium needs to be stopped. This usually happens at the time of initial yarn introduction through the ejection nozzle 3. For example, provided that a yarn of polypropylene fibers is processed through the crimping operation, thermal treatment is performed at a temperature almost equal to a fiber melting point. So, if the yarn is initially introduced through the ejection nozzle 3 without turning off the heating medium supply of such a high temperature, the fibers in the yarn tend to become molten and the initial introduction of the yarn through the ejection nozzle will end in failure. For carrying out the initial introduction of the yarn successfully, it is necessary to momentarily turn off the heating medium supply to the ejection nozzle.

Referring to FIG. 3, an embodiment of the mechanism for enabling this heating medium supply switching is shown. In this mechanism, the supply conduit of the ejection nozzle 3 is switchably connected to a main supply conduit through an aperture 16 of the latter. In a condition shown with full lines in the drawing, that is, the outlet of the ejection tube 7 is positioned adjacent to the peripheral surface of the rotational crimping member 5 in its operating condition, the heating medium 4 is passable through the connection by the aperture 16 and is introduced into the ejection nozzle 3. In a condition shown with dotted lines in the drawing, that is, the outlet of the ejection tube 7 is positioned remotely away from the peripheral surface of the crimping member 3 in its standby condition, the connection between the supply conduit 10 and the main supply conduit 15 is closed and the supply of the heating medium 4 into the ejection noule 3 is turned off.

Be employing the above-described mechanical designs switching mechanism in the crimping apparatus of the present invention, the following possibilities will be assured.

I. In case two or more ejection nozzles are used together in an aligned disposition, the respective yarn supply switching can be easily performed by only pivoting the corresponding ejection nozzle assembly around the main supply conduit in a manner independent from each other.

2. If the pivotal contact between the ejection nozzle assembly and the main supply conduit is adequately sealed with a heat resistant substance such as Teflon, a smooth assembly pivotation due to a sealing substance lubricational effect can be assured in addition to an effective pressure sealing.

The ejection nozzle or nozzles 3 can be either laterally stationary with respect to the rotational axis of the crimping member 5 or movable in that direction. In this regard, the crimping member 5 may be slidable in its axial direction, also. Consequently, by designing both as mutually movable in the above-described sense, the following possibilities can result.

1. Because the ejection point by the ejection nozzle 3 is laterally displaced on the peripheral surface of the crimping member 5, the mechanical attack on the surface by the ejection can be distributed over a long distance and local damage of the needle-like members or honeycombed protuberances planted on the surface can be effectively obviated. Consequently, the needle-like members or honey-combed protuberances are durable for long periods of use.

2. Because the deposited yarn is maintained on the surface in a zig-zag form because of the pins, the effective stay of the yarn on the surface can be elongated resulting in high speed impartation of stable crimps on the fibers.

The above-described lateral movement of the ejection nozzle or nozzles can be carried out by utilizing a suitable cam driving mechanism positioned sideways of the crimping member 5. In this case, no trouble will occur in the removal action of the yarn or yarns from the surface if the lateral sliding width is in a range from 10 to 15 mm.

Referring to FIG. 4, an embodiment of the arrangement for performing the distribution of the heating medium to a plurality of aligned ejection nozzles is shown. In the arrangement, a plurality of

ejection nozzles

30, 3b, 3c, .3n are connected respectively to the main supply conduit 15 in an adequately spaced and aligned disposition. The main supply conduit 15 is internally provided with one or more auxiliary heaters extending therein through for obtaining a uniform temperature distribution over all

ejection nozzles

30, 3b, 3c,

. 3n. The heating medium 4, supplied from a given supply source (not shown) through the main supply conduit 15, is additionally heated by the auxiliary heater or heaters 20 and distributed to each ejection nozzle 3.

By adopting the auxiliary heater 211) of an electric type, the temperature can be easily changed as desired by adjusting the magnitude of the electric voltage used, only.

In case the above-described heating medium distributing arrangement is used, the following advantages will thereby result.

I. The heating medium can be distributed uniformly to each ejection nozzle and the possible temperature lowering of the medium during the distribution can be effectively compensated for by the presence of the auxiliary heater or heaters disposed in the main supply conduit. Uniformity in both temperature and distribution can be assured.

2. Because the ejection nozzles are pivotally disposed to the main supply conduit, thermal radiation through the conduits wall can be effectively minimized and enhanced.

thermal efiiciency can be assured.

3. In this arrangement, the main supply conduit itself forms "1 l a support of the ejection nozzles, so a simple mechanical arrangement will result.

The angular relationship of the ejecting direction with I respect to the peripheral surface of the crimping member also plays an important role in determining the crimping effect on the apparatus of the present invention. In this regard, it is favourably recommended that the ejecting direction of the ejection nozzle 3 is perpendicular to a virtual tangent plane contacting the circle formed by the peripheral surface of the crimping member 5 at the ejection point. When the angular relationship is selected in this manner, the ejection force provided by the heating medium under pressure can be mostly utilized in pushing the yarn 1 sufficiently into the spaces 5b and, consequently, crimp impartation can be performed with satisfactory results even in the case of relatively large thickness yarn.

The distance between the outlet of the ejection noule 3 and the peripheral surface of the crimping member 5 should advantageously be selected as short as possible. By thusly selecting the intervening distance, the difference between the fibers ejection pressure and the fibers push-in pressure can be almost minimized and a sufficient crimp impartation will be ascertained. This distance should favourably be 10 mm or shorter and when the heated medium is ejected from such a close position to the surface of the crimping member, the ejected medium tends to reflect from the surface and escalate the temperature of the atmosphere surrounding the crimping member 5 for enhanced thermal effect on the fibers composing the yarn 1.

Referring to FIG. 5, a mechanism for adjusting the crimped yarns removal speed from the crimping member's peripheral surface is shown. In the vicinity of the planed removal point of the crimped yarns 21a, 21b and 21c from the surface of the crimping member 5, the pair of cooperating conical delivery rollers 60 and 6b are positioned. A contact line of the

rollers

6a and 6b is directed almost perpendicularly to a radial line extending from the rotational axis of the crimping member 5 and the large-diametral ends of the

rollers

6a and 6b are directed toward the rotational direction member 5.

After the fibers inthe supplied multifilament yarn 1 is provided with crimps during their stay in the spaces 5b on the crimping members surface, they must be removed therefrom.

Provided that the crimped yarn 21 is removed from the surface into a direction parallel to the extending direction of the needle-like protuberences 5a at a location A on the surface, the removal speed of the crimped yarn 21 is determined in accordance with a nominal fiber thermal :shrinkability composing the yarn 1. When the actual fiber thermal shrinkability is smaller than the nominal value, the actual removal point of the yarn 21 deviates towards a downstream location B. Due to these positional deviations, the nip point of the yarn 21, by the of the crimping

rollers

6a and 6b, moves towards the large-diametral ends of the

rollers

6a and 6b, the yarn 21 is now taken up at an increased take-up speed and the actual removal point gradually returns to its initial location A. On the contrary, in case the actual thermal shrinkability is larger than the nominal value, the actual removal point of the yarn 21 deviates towards an upstream location C, the nip point of the yarn 21, by the rollers 60 and 6b, moves towards the small-diametral ends of the

rollers

6a and 6b, the yarn 21 is now taken up at a decreased take-up speed and the actual removal point gradually also returns to its initial location A.

In the manner above-described, the crimped yarn 21 can be removed from the surface of the crimping member at an optimum removal point whereon the resistance against removal is smallest in accordance with the lengthwise variation in the thermal shrinkability of a single yarn or variation in the thermal shrinkabilities of a plurality of yarns.

The percent degree of the surface taper of the

rollers

6a and 6b is so selected as to be slightly larger than the percent variation or deviation of the yarns thermal shrinkability. For example, when the percent fluctuation of the yarns thermal shrinkability is i 7, the percent increase in the rollers diameter at its largest-diametral end should favourably by about 10% with respect to the rollers diameter at its middle length portion and the percent decrease in the rollers diameter at its smallestdiametral end should favorably be about l0% in the same sense. One of the pairs of

rollers

6a and 6b is constructed in the form of a driven roller and the other in the form of a pressure roller, the latter being preferably urged towards the former utilizing a suitable urging mechanism such as a spring. By employing the taking up means of the above-described type, it is possible to process two or more yarns simultaneously to the crimping member and to bundle them together at the time of yarn take-up without enlarging the occupying space by the taking-up means. The taking-up means of the present invention is provided with a relatively simple mechanical design and is accompanied with ease in the handling operation. Further, even in case two or more yarns are to be nipped by the

delivery rollers

6a and 6b, the removal point automatically displaces sideways, as above-explained, for an effective prevention of the locational damage to the rollers surface and the fibers contained in the yarns can be somewhat opened due to a rubbing effect by a sliding contact of the yarns with the rollers surface during the lateral displacement.

As is already explained in the foregoing description, fibers composing the multifilament yarn l and ejected from the ejection nozzle 3 are pushed into the spaces 5b formed on the crimping members surface by the numerous protuberances 5a and are deformed into crimped configuration during their stay in the spaces 5b. A superior crimping effect results from a superior thermal effect. In this regard, however, sufficient cooling of the crimped fibers can hardly be attained during their period of stay within the space 5b, that is, during the period from ejection to removal. lnsufiicient cooling of the crimped yarn often tends to lead to a variable crimping effect and disappearance of the imparted crimps. Although increase in the crimping members diameter may somewhat obviate this drawback, it tends to result in enlargement of the whole arrangement of the apparatus, trouble in driving the apparatus of such an enlarged arrangement and less adaptability for an effective mass-production.

A mechanism for achieving the above-described effective cooling of the crimped yarn is illustrated in FIG. 6, wherein the mechanism comprises yarn cooling means 17 disposed facing the crimping member 5 in the vicinity of the yarn removal point. The yarn cooling means 17 comprises a pair of slidably superposed perforated plates 18a and 18b and the cooling air flow rate passable therethrough can be changed as desired by adjusting the superposed relationship between the two plates 18a and 18b. The yarn cooling means 17 can also be in the form of a perforated plate slidably superposed with a shutter plate and the cooling air flow rate passable therethrough can be changed as desired by adjusting the surface area of the perforations through sliding of the shutter plate.

By providing the crimping apparatus of the present invention with cooling means of the above-described type, it becomes possible to shorten the time the crimped yarn stays within the spaces 5b on the crimping members surface while insuring a sufficient cooling effect on the yarn within a short period. This results in desirable compactness of the apparatuss construction, that is, the diameter of the crimping member can be minimized without lowering the stability of the imparted crimps. The intervening distance between the opening of the cooling means and the peripheral surface of the crimping member should preferably be 20 mm or shorter.

It is also recommendable to provide the crimping member of the present invention with a plain peripheral surface. When the heated multifilament yarn 1 is transferred on the peripheral surface of this design, the yarn portion contacting the surface portion having needle-like protuberances will be provided with crimps and the yarn portion contacting the plain surface portion will not be provided with crimps. Thus, the resultant yarn can be provided with a novel configuration, wherein the crimped portions and the non-crimped portions alternatively extend lengthwise.

The crimping member of the present invention can be made not only in the form of a cylinder but also in the form of an endless belt. Further, the protuberances are not limited only to needle-like members or honey-combed protuberances. Various types of protuberances can be used to define spaces in conformity to the requirement of the end products.

As is well understood from the foregoing discussion, the yarn processed through the crimping apparatus of the present invention can possess excellent entanglement of the component fibers and a random disposition of the component fibers in the yarn configuration. The shape of the crimps thus obtained is essentially different from those obtained by the conventional technique and the individual filamentary fiber is provided with three-dimensional smooth curves in its shape.

Therefore, the crimped yarns manufactured on the crimping apparatus of the present invention are provided with enriched bulkiness and soft and comfortable hand feeling. They are further advantageous in that, when the yarns are used for textile products such as carpets, a lesser quantity of yarn is necessary than in the case where the crimped yarns are manufactured on the conventional-type crimping apparatuses.

Further, employment of the ejection nozzle of the type shown in FIG. 2 achieves the following advantageous results.

1. Because the heating medium passes through the path encircling the main heating tube, the heating tube can be supplementally heated and the yarn passing through the main heating tube can be indirectly heated resulting in a remarkably enhanced thermal efficiency.

2. The processed yarn can be subjected to direct contact with the heating medium for a long distance, that is, the main heating tube is elongated and, accordingly, the fibers in the yarn can be sufficiently heated at a desired temperature.

3. By making the distance between the yarn guide tube and the heating tube adjustable, the ejection force of the yarn can be adjusted as desired. Further, when a plurality of ejection nozzles are used in an aligned arrangement, the crimp impartibility of the number of ejection nozzles can be equalized.

Owing to the above-described advantages, the apparatus of the present invention can produce crimped yarns of various types.

Further, due to the installation of the take-up speed adjusting mechanism, the yarn can be taken off from the peripheral surface of the crimping member at a position of the minimum removal resistance regardless of the variation in the thermal shrinkability of the componentary fibers of the yarn. In addition to this, local damage of the protuberances can be effectively prevented resulting in considerable longevity of the apparatus.

Further, such operational troubles as yarn breakages or fluff formation can be advantageously obviated ascertaining production of bulky yarns of enhanced quality. Simple mechanical construction of the taking-up means remarkably contributes to enhancement in the productivity.

It should again be well understood that by using the crimping apparatus of the present invention, yarns of large thickness can be processed through the crimping operation at high speed without incidences of yarn breakage accidents. Relatively simple mechanical construction and occupying space of the apparatus can present a great advantage in the practical production of the crimped yarn.

The following examples are illustrative of the art of the same.

EXAMPLE 1 A polypropylene multifilament yarn of 1,850 denier thickness containing 120 filaments was supplied to a crimping apparatus of the present invention, a conventional ejection nozzle of a short heating distance type and an ejection nozzle of the present invention shown in FIG. 2 being simultaneously used in an aligned arrangement on a same crimping apparatus. The crimping operation was carried out under the following processing conditions.

Processing speed Heating medium Heating temperature (Temperature of the mediumat the outlet of the ejection nozzle) Pressure of the steam within the ejection nozzle Supply speed of the yarn Surface speed of the rotational crimping member 90 mlmin super-heated steam 1.6 kg/cm The resultant crimp-property of the yarns was as is shown in the following Table 1.

TABLE 1 Type of Percent crimp Percent Percent crimp nozzles used elongation crimp recovery Conventional 33.7 20.5 84.0 Present Invention 43.2 26.8 83.2

EXAMPLE 2 Nylon 6 multifilament yarn of 1,260 denier thickness containing 60 filaments was processed through the apparatus, the same as that used in the foregoing example, and using two types of nozzles. The processing conditions were as follows.

Process speed 140 m/min Heating medium super-heated steam Heating temperature 190 C Pressure of the steam 1.8 kg/cm within the nozzle Supply speed of the yarn S urface speed of the rota- I10 tional crimping member The resultant yarns were provided with crimp properties as shown in Table 2.

TABLBZ Type of Percent crimp Percent Percent crimp nozzles used elongation crimp recovery Conventional 49.8 27.5 85.3 Present invention 63.3 34.7 84.]

Even in the case of nylon fibers, the superiority of the ap-' EXAMPLE 3 In this experimentation, two types of ejection nozzles the same with those used in Example 1 were used for processing a polyester multifilament yarn of 1,560 denier thickness containing 60 filaments at a processing speed of MPM. Super heated steam was used as the heating medium and the heating temperature was of 205 C. Pressure of the used steam within the ejection nozzles was of 1.9 kg/cm and the ratio of the supply speed of the yarn with respect to the surface speed of the rotational crimping member was of 11.5. The resultant crimpproperty of the yarns was as is shown in the following Table 3.

TABLE 3 Type of Percent crimp Percent Percent crimp nozzles used elongation crimp recovery Conventional 45.1 25.3 84.5 Present invention 58.4 30.5 85.0

As is apparent from the above-shown results, an appreciable effect can be expected for use of the ejection nozzle of the present invention as to polyester fibers. By enhancing the heat-settability of the polyester fibers to be processed, it is feasible to employ a higher processing speed of the yarn.

EXAMPLE 4 TABLE 4 Type of Percent crimp Percent Percent crimp nozzles used elongation crimp recovery Conventional 43.5 18.5 74.1 Present invention 55.7 23.4 77.5

The above data clearly show the advantage of the ejection nozzle of the present invention over the conventional one and, in the case of polyacrylic fibers, the processing speed of the yarn can be elevated far more through elevation of the heating temperature.

What is claimed is:

1. A yarn crimping apparatus for manufacturing a bulky yarn comprising, rotationally driven crimping means including a surface having protuberances thereon defining a multiplicity of fiber-receptive spaces for crimping yarn fibers delivered into said spaces, an ejection nozzle spaced from said surface for ejecting plastified yarn fibers therefrom and delivering the yarn fibers in a plastified state into said spaces as said crimping means is driven for crimping said yarn, means for taking-off the crimped yarn from said crimping means after setting the crimped yarn and for taking it off at speeds automatically adjusted according to variations in the thermal shrinkability of the yarn fibers, and means to supply the yarn to said nozzle at a substantially constant supply speed.

2. A yarn crimping apparatus according to claim 1, including coacting means to set the yarn disposed intermediate said nozzle and said means for taking-off the crimped yarn.

3. A yarn crimping apparatus according to claim 1, in which said means for taking off said yarn comprises two rotationally driven conical rollers coacting to take-off said yarn.

4. A yarn crimping apparatus according to claim I, in which said protuberances extend outwardly from said surface substantially perpendicularly thereto.

5. A yarn crimping apparatus according to claim 1, in which the distance between an outlet of said nozzle and said surface is no greater than 10 mm.

6. A yarn crimping apparatus according to claim 1, in which the distance between an outlet of said nozzle and said surface is less than 10 mm.

7. A yarn crimping apparatus according to claim 1, in which said protuberances are substantially perpendicular to said surface, and in which said means for taking-off said crimped yam comprises means disposed to take 011' the yarn from said crimping means substantially perpendicularly to said surface.

8. A yarn crimping apparatus according to claim 1, in which said means for taking-off said crimped yarn comprises coacting driven conical rollers having their greatest diameter disposed in a direction toward which said crimping means rotates.

Claims

4. A yarn crimping apparatus according to claim 1, in which said protuberances extend outwardly from said surface substantially perpendicularly thereto.

7. A yarn crimping apparatus according to claim 1, in which said protuberances are substantially perpendicular to said surface, and in which said means for taking-off said crimped yarn comprises means disposed to take off the yarn from said crimping means substantially perpendicularly to said surface.