US3721070A

US3721070A - Self-sealing dust bag

Info

Publication number: US3721070A
Application number: US00027509A
Authority: US
Inventors: K Minami; T Masaaki; M Hirota; T Nakaue; K Susami
Original assignee: Toray Industries Inc
Current assignee: Toray Industries Inc
Priority date: 1969-04-14
Filing date: 1970-04-13
Publication date: 1973-03-20
Anticipated expiration: 1990-03-20
Also published as: FR2039168B1; DE2017889A1; GB1311731A; DE2017889B2; CH510139A; FR2039168A1

Abstract

A self-sealing dust bag for a vacuum cleaner provided with an inlet tube. The bag includes a body of relatively porous pliable dust-impermeable material and a relatively stiff plate portion provided with an aperture for the reception of the inlet tube. A patch of resilient elastic, dust-impermeable material is secured to the inner side of the stiff plate portion. The patch is provided with an aperture smaller than and in registry with the plate portion aperture. A bridge is integral with the stiff plate portion and extends over the aperture therein. The bridge includes a bulbous central section and two oppositely located connecting sections. The bulbous section is larger than the patch aperture and smaller than the stiff plate portion aperture. The bulbous section is frangible at the junction line between the bulbous section and one of the connecting sections to allow for the reception of the inlet tube in the stiff plate portion aperture.

Description

United States-Patent 1 Minami et al.

METHOD AND APPARATUS FOR PRODUCINGYARNS BY THE OPEN- END SPINNING SYSTEM In r Keilchi Minami, Tokuji Nakaue, Kozo Susami, Tabata Masaaki, Otsu; Masakazu Hirota, Shiga, all

i 11 3,721,070 151..Man20l273 [5 6] References Cited UNITED STATES PATENTS 3,455,097 7/ 1969 Rajnoha et al ..57/58.95 3,443,372 5/1969 Eddleston ..57/58.89 3,601,969 8/1971 s usami et al ..57/58.95 X 3,604,194 9/1971 Edagawa et al. 3 ,501,907 3/1970 Tabata start; 3 ,535 ,868 10/ l 970 Schiltknecht ..57/58.95 3,494,118 2/1970 Bobkowicz et al ..57/58.95 X 3,538,698 11/1970 Ripka et al ..57/58.95

frimgry Examiner: Donald E. Watkins A ttorney Maleson, Kimmelman and Ratner [57] ABSTRACT Open-end spinning method and apparatus utilizing a spinning rotor, wherein, fibers of the textile staple material are separated from a fiber bundle due to a mechanical pulling-out action created by a pair of rotating rollers which operate at a very high peripheral speed and simultaneously, the separated fibers are feddirectly or through a guide member to a collecting surface of the spinning rotor mainly by the inertia of each individual fiber.

6 Claims, 9 Drawing Figures PATENTEDMARZO 1915 3, 721. 070

' SHEET 10F 5 INVENTOR ATTORNEYS PATENTEDMARZOIBYS 3.721.070

' SHEET 20F 5 INVENTOR I 'PATENTEDMAREO I973 sum 30F 5 INVENTOR BY A II lu'kfumulAzrw R'JEY s SHEET t 0F 5 INVENTOR ATTO R N EYS sum 5 u; s

PATENTEDMAR20 I973 INVENTOR ATTORNEYS METHOD AND APPARATUS FOR PRODUCING YARNS BY THE OPEN-END SPINNING SYSTEM BRIEF SUMMARY OF THE INVENTION material are liberated from a fiber bundle continuously fed from a supply source and simultaneously, e51 liberated fiber is ejected individually onto a collecting surface of the spinning rotor and collected thereupon,

then, a continuous fresh bundle of fibers is taken off from the collecting surface while imparting twists thereto.

In the conventional open-end spinning apparatus, fibers of the textile staple material are separated from a continuous fiber bundle and thereafter, the separated fibers are fed into a spinning rotor or fiber-collecting means such as a chamber wherein an eddy air current is applied so as to form a continuous fresh bundle of fibers and the fresh bundle of fibers is taken off from the spinning rotor or fiber collecting means while imparting twists thereto so that a twisted yarn can be continuously produced. In the above-mentioned open-end spinning, it is an essential condition for producing a good quality yarn that the individual fibers are completely separated from the continuous bundle of fibers fed from a supply source before feeding the individual fibers to the fiber-collecting means. Since the separation of individual fibers from the continuous bundle of fibers means liberation of individual fibers from mutual interference between then in the technical meaning, the finer the thickness of the individual fibers, or the longer the length of these individual fibers, the more difficult the separation of these fibers from the continuous bundle of fibers. Therefore, the application of the open-end spinning method is actually limited in producing yarns of short fibers such as cotton fiber, at present.

It is said that individual fibers having a long staple length more than 2 inches can be liberated from a continuous bundle of fibers by applying a separation roller such as the well-known carding roller, if the diameter of the separation roller is settled in an appropriate condition to the length of the individual fibers. However, even though the separation of the long fibers is carried out satisfactorily by applying the above-mentioned means, it is very difficult to carry the separated fibers to the collecting means in a mutually parallel condition along the lengthwise direction. thereof. Even though the separated individual fibers are delivered at a high speed from the separation roller, the carrying speed of the fibers becomes slow after being delivered from the separation roller and the separated individual fibers are frequently bent or entangled with each other while being carried to the fiber collecting means so that the parallelism between the separated individual fibers is broken.

Therefore, in the conventional open-end spinning apparatus, the finer the thickness of the individual fibers, or the longer the length of the individual be produced, the variation of yarn thickness is large and the strength thereof is very low.

The principal object of the present invention is to provide an improvement in the open-end spinning method and apparatus, wherein individual fibers are liberated from a continuous bundle of fibers supplied from a supply source and simultaneously the liberated fibers are ejected to a rotating spinning rotor while maintaining mutual relation of the lengthwise pafallelism thereof, and a fresh bundle of fibers is taken off from a collecting surface of the spinning rotor while imparting twist to the fresh bundle of fibers, so that the above-mentioned drawbacks of the conventional open-end spinning can be eliminated, in other words, yarns having excellent qualities can be produced.

In the open-end spinning apparatus provided with a device for supplying a continuous bundle of fibers and a spinning rotor, the improved apparatus according to the present invention principally comprises a liberation device such as a pair of pulling-out rollers disposed between the supplydevice and the spinning rotor so that the individual fibers are liberated from the continuous bundle of fibers by pulling action of the pulling-out rollers and simultaneously each liberated fiber is ejected individually to the spinning rotor predominantly by the inertia thereof. lt is required that the rotation speed (peripheral) of the pulling-out rollers should be high enough to attain the above-mentioned function thereof, for example, it is preferable that a draft ratio depending upon the action of the pulling-out rollers is larger than :1. Therefore, the above-mentioned method of ejecting the liberated fibers to the spinning rotor by utilizing the inertia thereof can be considered as one of the characteristic functions of the present invention. It is also one of the characteristic functions of the open-end spinning method of the invention that the individual fibers are liberated from the continuous bundle of fibers by simultaneously applying the pulling action created by the high speed rotation of the pulling-out rollers.

In the above-mentioned spinning apparatus provided with a device for supplying a continuous bundle of fibers and a spinning rotor, any device for supplying a sliver or a roving to the separation device of the invention can be used. Since the liberated fibers are not conveyed to the spinning rotor by a suction air stream, the spinning rotor of an open type is preferably used for the present invention. However, a spinning rotor having a function of receiving a blowing air stream is also available if it is desired to supply an air stream in addition to the above-mentionedutilization of inertia of individual fibers. The latter function is particularly useful for spinning yarns of coarse count or yarns composed of long fibers. As a result of our experiment, it was found that an eddy air current is created in a space between the pulling-out rollers and the spinning rotor by the high speed rotation of the pulling-out rollers and the high speed rotation of the spinning rotor. This eddy air current is also created when the liberated fibers are wrapped about the pulling-out rollers. Consequently, there is a tendency to dishevel the arrangement of individual fibers. And in case of thicker thickness of the bundle of fibers, the arrangement of individual fibers in the bundle of fibers is also easily dishevelled at positions before and after the nip point of the pulling-out rollers. To eliminate the above-mentioned trouble, in the principal method according to the present invention, a guide pipe for-leading the liberated fibers to the spinning rotor is disposed between the pulling-out rollers and the spinning rotor, wherein a compressed air stream' is flowing along an inside surface thereof, so that the liberated fibers are effectively ejected to a collecting surface of the spinning rotor without dishevelling the parallel lengthwise arrangement of fibers by forming an air stream. The above-mentioned characteristic function of the air stream is distinctly helpful for producing the coarse count yarn or yarn composed of fibers having fairly long staple length. It is preferable that the distance between the nip point of the pulling-out rollers and the collecting surface of the spinning rotor is defined so that the above-mentioned distance is longer than the average length of individual fibers in the bundle of fibers while the length DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING FIG. 1 is a schematiceleyationpartly in section, of a basic spinning apparatus according to the present invention.

FIG. 2 is a schematic elevation, partly in section, of a modified embodiment of the apparatus shown in FIG. 1,

FIG. 3 is a schematic elevation partly in section, of another modified apparatus according to the present invention,

FIG. 4 is a sectional side view of another guide pipe which is available for the apparatus shown in FIG. 3,

FIG. 5 is a schematic elevation partly in section, of another modified apparatus according to the present invention,

FIG. 6A is a schematic elevation partly in section, of another modified apparatus according to the present invention,

FIG. 6B is a side view, of the apparatus partly, in section, looking from a side VI B-VI Bin FIG. 6A,

FIG. 7 is a sectional view of the collector, taken along a line VII-VII in FIG. 6A,

FIG. 8 is an elevational view of a pair of pullingout rollers shown in FIG. 6A.

DETAILED DESCRIPTION OF THE INVENTION A basic improvement of the open-end spinning apparatus according to the present invention is hereinafter illustrated in detail with reference to FIG. 1. In FIG. 1, a continuous bundle of fibers l is supplied at a constant speed from a pair of

feed rollers

2, 2. A pair of pulling-out rollers 4, 4' are disposed between the feed rollers 2, 2' and a spinning rotor 5.

and the pulling-out

rollers

4, 4 rotate at remarkably higher peripheral speed than that of the feed rollers 2, 2'. A generally funnel-shaped collector 3 guides the fibers from the

feed rollers

2, 2 between the pulling-out

rollers

4, 4. The distance between the nip point of the

feed rollers

2, 2 and that of the pullingout rollers 4, 4' is selected so that the above-mentioned distance is longer than the average length of the individual fibers. Therefore, individual fibers of the continuous bundle of fibers delivered from the feed rollers 2, 2' are liberated from the bundle 1 by the drafting action created by the high speed rotation of the pulling-out

rollers

4, 4, because the abovementioned drafting action is carried out at a very high draft ratio. Since the pulling-out rollers 4, 4' are rotated at a very high speed, the liberated individual fibers are ejected in the common tangential direction of the pulling-out

rollers

4, 4 separately by inertia thereof created by the high speed rotation of the rollers 4, 4'. The spinning rotor 5 is located at an adjacent under positionof the pulling-out rollers 4, 4' so that the ejected individual fibers are collected upon a collecting surface of the spinning rotor 5 and a fresh bundle of fibers is continuously taken off from the collecting surface by a pair of take-up rollers 11, 11', while twisting the bundle. Therefore, the construction of the apparatus is very simple and the yarn having good quality can be continuously produced without any troubles such as damage of fibers or creating hooks at the ends of fibers.

In the above-mentioned illustration, the term very high draft ratio means a draft ratio which is sufficiently high to liberate the individual fibers from the continuous fiber bundle. To attain the abovementioned draft action, it is required to impart very positive draft of more than times to the continuous bundle of fibers 1 at a drafting field between the

feed rollers

2, 2 and the pulling-out

rollers

4, 4. If the draft ratio is in the range 30-4011, which is considered as a maximum draft ratio of the ring spinning frame, is applied to liberate the fibers from the continuous bundle of fibers 1. it is difficult to liberate the individual fibers satisfactorily, the individual fibers rather interfere with each other.

Since the liberated individual fibers are ejected separately to the spinning rotor 5 by utilizing the inertia thereof, the rotating sp ed of the pulling-out rollers 4, 4' is required to be sufficiently high to create the inertia of the individual fibers. thereby the the liberated fibers are ejected and the common tangential direction of the pulling-out rollers 4. 4 The mass of the individual fiber is represented by m, the angular velocity of the pulling-out rollers is w, the cross-sectional diameter of the pulling-out rollers r, the kinetic energy E imparted to the individual fibers is represented by the following expression:

Therefore, it can be understood that the larger the mass m of the individual fiber. or the larger the thick ness of the individual fiber, the larger the kinetic energy E. so that the ejection of the individual fibers to the spinning rotor can be carried out easier ()n the other hand, if the angular velocity w of the pulfih g-out rollers is small, there is a tendency of wrapping the liberated individual fibers about the pulling-out rollers. By our experimental test, in case of using a spinning material which is polyacrylonitrile fiber of 15 denier, 152 mm long, it is required that the peripheral speed V(=rw) is more than 190 meter/min.

Therefore, if the textile fiber material of 1.5 denier is used for producing a yarn by the present apparatus, it is required that the peripheral speed of the pullingout rollers V= V1 X 190 meter/min for creating the kinetic energy similar kinetic'energy to that of the textile fiber material of 15 denier. However, since the above-mentioned calculation is based upon an assumption that the liberation of the individual fibers from the continuous bundle of fiber is carried out without any resistance, it is actually required to further speed up the rotation speed of the pulling-out rollers for ejecting fine and long staple fibers toward the spinning rotor satisfactorily.

By our experiment, pertinent peripheral speeds of the pulling-out rollers for ejecting individual fibers of various fiber lengthes to the spinning rotor are shown in the following Table l.

' TABLE 1 Pertinent peripheral speed Fineness x Fiber length of the pulling-out rollers Class (denier) x (mm) without wrapping fibers thereupon (meter/min) I 15 152 190 2 10 I52 200 3 7 I02 350 4 5 I02 400 5 3 89 600 Since the above-mentioned pertinent W peripheral speed of the pulling-out rollers can be considered as a critical speed of the pulling-out rollers so that the wrapping of individual fibers about the rollers can be prevented, it is understood that the fibers having shorter length than the above-mentioned fiber length of a certain class can be ejected satisfactorily at the pertinent peripheral speed corresponding to the class. Table 2 shows the relations between fineness and As it is shown in the above-mentioned test results, in case the product of mass of individual fibers m and square of the peripheral speed v of the pullingout rollers" mv is larger than 25.0, the wrapping of fibers about the pulling-out rollers is eliminated and each liberated individual fiber is ejected directly to a common tangential direction of the pulling-out rollers. The larger the product of m and v*, the larger the flight distance of individual fibers from the pulling-out rollers. On the other hand, in case the product of m and v is small, particularly in case of spinning very fine fibers, wrapping of the individual fibers about the pulling-out rollers frequently happens.

It is also confirmed by our experiment that, in case of applying a thick continuous bundle of fibers, the frequency of wrapping fibers about the pulling-out rollers is decreased in accordance with approaching mv to 25.

Referring to FIG. 2, which shows a modification of the apparatus shown in FIG. 1, a bundle of fibers 1 is fed to means for liberating individual fibers by a pair of feed rollers 2, 2' provided with respective aprons 13, 13', after passing through a collector 3. The individual fibers are liberated from the bundle l by a pair of pulling rollers 4, 4' which creates an intensive draft action at a draft ratio at least times, and the liberated individual fibers are ejected to a collecting surface of a spinning rotor 5 by inertia thereof created by the high speed rotation of the pulling-out

rollers

4, 4. Then, a fresh bundle of fibers is taken off from the collecting surface of the spinning rotor 5 by a pair of take-up rollers 11, ll while twisting it so that a yarn 10 is formed, and the yarn 10 is taken up by a winding roller 12 through a delivery pipe 9 of the spinning rotor 5. It is preferable that a stationary guide 7 is inserted into the spinning rotor 5 and further, a plurality of air discharging aperatures 8 are formed at an adjacent surface below the fiber collecting surface of the spinning rotor 5 so as to prevent contacting the ejected fibers with the fresh bundle of fibers taken off from the above-mentioned collecting surface. By applying the above-mentioned attachment and construction of the spinning rotor 5, the liberated individual fibers are smoothly ejected to the fiber collecting surface of the spinning rotor 5. It is further desirable that a pair of casings 6, 6 are used for coven'ng the feeding side of the pulling-out rollers 4, 4' and both sides of the pulling-

outv rollers

4, 4 are also covered. The

aprons

13, 13 or both the

aprons

13, 13 and the stational'casings 6, 6 may be omitted. The pulling-out

rollers

4, 4 having larger diameter than that of the

feed rollers

2, 2 are preferably employed for obtaining high peripheral speed thereof so that wrapping of the liberated individual fibers about the pulling-out rollers 4, 4' can be prevented. Various types of pulling-out rollers 4, 4' are available for example, rubber rollers, fluted metallic rollers, metallic rollers provided with toothed shaped surfaces etc.

By employing the above-mentioned pulling-out rollers, various kinds of textile fibers,'particularly fibers of coarse fineness can be satisfactorily spun.

Example I A yarn is spun by an open-end spinning apparatus shown in FIG. 2, under the following conditions of Table 3.

Feeding speed of the continuous bundle of fibers 2.l mlmin Diameter of the pulling-out rollers 60 mm Rotation speed of the pulling-out rollers 4,000 r.p.m. Draft ratio between the feed rollers and the pulling-out rollers 358 Peripheral speed ofthe pulling-out rollers 7S4 mlmin (I257 cm/sec) Initial ejecting speed of the individual fibers 754 mlmin from the pulling-out rollers (I257 cm/ sec) Maximum inside diameter of the spinning rotor I20 mm Rotation speed of the spinning rotor I2,000 r.p.m. Yarn count (metric system) l/S Spinning speed 50 mlmin Distance between the nip point of the pullingout rollers and a particular position on the collecting surface of the spinning rotor. (Note:

The particular position is defined by an intersecting point of an elongated line along the surface of the stationary guide 7 with the collecting surface of the spinning rotor in FIG.

By applying the above-mentioned apparatus, each liberated individual fiber is ejected along a common tangential direction of the pulling-out rollers and fed to the collecting surface of the spinning rotor 5 after touching the stationary guide 7, without creating any hooks of the fiber ends. On the other hand, many hooks of the fiber ends are observed in fibers collected upon the collecting surface of the spinning rotor 5 in case of utilizing a fiber-liberating roller covered with a metallic wire or wires.

Qualities of yarn (A) produced by the apparatus shown in FIG. 2 under the above-mentioned condition is compared with that of yarn (B) produced by the open-end spinning apparatus utilizing the abovementioned carding roller instead of the pulling-out rollers, as shown in Table 4.

Therefore, high tensile strength is one of the features of the yarn produced by the apparatus of the present invention.

As mentioned above, the individual fibers liberated from the continuous bundle of fibers are ejected from the pulling-out rollers to the spinning rotor. However, since the flying speed of the individual fibers ejected from the pulling-out rollers is lowered rapidly, in case of spinning yarn from textile fibers having coarse fineness or long staple length, it is desirable to guide positively the liberated fibers flying to the collecting surface of the spinning rotor so as to prevent entangling fibers or dishevelling of the parallel mutual condition of the fibers.

A modified apparatus utilizing the above-mentioned positive guide member is shown in FIG. 3. In the illustration of this apparatus, the identical elements of the apparatus shown in FIGS. 1 and 2 are represented by the same numerals as in FIGS. 1 and 2. In this embodiment, the continuous bundle of fibers 1 is supplied to the feed rollers 2, 2' at a constant speed. The bundle of fibers 1 is subjected to a draft action which is created by the pulling-out

rollers

4, 4 rotating at a higher peripheral speed at least 100 times the peripheral speed of the

feed rollers

2, 2 so that the individual fibers are liberated from the bundle of fibers 1, and the liberated individual fibers ejected from the pulling rollers 4, 4' are simultaneously directed into a guide pipe 14 without changing relative positions of the liberated fibers. The distance between the nip points of the feed rollers 2, 2' and the pulling-out rollers 4, 4' is selected so that this distance is a little longer than the average fiber length of the individual fibers. Therefore, the individual fibers can be completely liberated by the super high drafting action created by the pulling-out rollers 4 and 4'. The guide pipe 14, adjacently disposed to the delivery side of the pulling-out

rollers

4, 4, is provided with a branch pipe 15 so as to supply compressed air therein and compressed air is ejected into the spinning rotor 5. Consequently, an aspirating action is created at an entrance portion 16 of the guide pipe 14 so that the liberated individual fibers delivered from the pulling-out

rollers

4, 4 are urged into the pipe 14 and carried to a fiber receiving surface 5a of the spinning rotor 5 one by one, and then the individual fibers received upon the receiving surface 5a are gradually removed to a collecting surface 5b by their centrifugal forces based upon the high speed rotation of the spinning rotor 5. Next, a fresh bundle of fibers is taken off from the collecting surface 5b while imparting twist thereto and taken up through the delivery pipe 9 of the spinning rotor 5 by a pair of take up rollers 11, 11 so as to form a package by means of the winding roller 12.

It is important that, the liberated individual fibers are let into the entrance portion 16 of the guide pipe 14 from their leading end one by one while being gripped by the pulling-out rollers 4, 4' and exposing them to an aspirating air stream flowing towards the spinning rotor 5. The individual fibers directed into the guide pipe 14 are carried to the receiving surface 5a of the spinning rotor 5 just after their rear ends leave the nip point 4a of the pulling-out

rollers

4, 4. Therefore, the distance L. between the nip point 4a of the pulling-out

rollers

4, 4 and a particular position defined by an intersecting point 56 of an extended line along a longitudinal axis of the guide pipe 14 with the receiving surface 5a of the spinning rotor 5. is selected in such a way that L is a little longer than the average length I of the individual fibers, and it be required that the length L2 of the guide pipe 14 is a little shorter than I. If, L2 is longer than 1, since the individual fibers having left their rear end portions from the nip point 4a of the pulling-out

rollers

4, 4, are carried freely, these fibers entangle with each other while being carried in the air stream. In case of using textile fibers having a short length such as cotton fiber, the frequency of entanglement of liberated fibers is actually low. On the other hand, if the length of fiber is long, for example longer than 2 inches, it is required to prevent the above-mentioned entanglement of fibers for carrying out the practical spinning operation.

In the above-mentioned embodiment, since the length L of the guide pipe 14 is shorter than the average length I of the individual fibers, the offset position of the branch pipe 15 can be settled at a pertinent position of the guide pipe 14.

By applying the guide pipe 14 to the spinning apparatus of the present invention, the liberation of individual fibers'from the bundle thereof can be carried out satisfactorily while the liberated individual fibers are ejected to the spinning rotor without dishevelling the parallelism of their mutual arrangement, so that practical yarns having good quality of evenness can be continuously produced.

Example 2 An acrylic yarn is produced from a sliver of polyacrylic fibers (7 denier x 102 mm, sliver weight 2 g/meter) by an open-end spinning apparatus of FIG. 3, wherein a guide pipe utilizing an air ejector shown in FIG. 4 is disposed between the pulling-out rollers 4, 4' and the collecting surface of the spinning rotor 5 with an inclined angle 30 to the collecting syx ass-m- The dimension of the guide pipe and the spinning conditions are shown in the following tables (Tables 5 and 6).

TABLE 5 Entire length L2 of the guide pipe 90 mm Inside diameter of the entrance portion of the guide pipe 8 mm Inside diameter of the delivery portion of the guide pipe 12 mm Pressure of the compressed air source 0.5 kg/cm Actual flow rate of the used compressed air 20 l/min Gauge between the feed rollers and the pulling-out rollers 105 mm Diameter of the pulling-out rollers 50 mm Rotation speed of the pulling-out rollers 5,000 r.p.m. Peripheral speed of the pulling-out rollers 785 mlmin (1,310 cm/sec) Peripheral speed of the feed rollers 3.1 mlmin Draft ratio 253 Distance L, 1 10 mm Maximum inside diameter of the spinning rotor l 10 mm Rotation speed of the spinning rotor 20,000 r.p.m. Count of yarn (metric system) 1/10 Spinning speed 60 m/min Average length I of the individual fibers I02 mm By applying the above-mentioned condition; the open-end spinning is carried out for a long time without any yarn breakage. The quality of the produced yarn is shown in Table 6, as follows.

An apparatus shown in FIG. 5 is a modification of the above-mentioned apparatus shown in FIG. 3. In FIG. 5, since the functions of the

feed rollers

2, 2, the pulling-out

rollers

4, 4, the collector 3, the spinning rotor S, the take-up rollers 11, 11' and the winding roller 12 are identical to the corresponding elements of the apparatus shown in FIG. 1, any illustrations of these elements are omitted. Therefore, the functional feature of the guide pipe is hereinafter illustrated. In this embodiment, the guide pipe 14 comprises a pair of air supply pipes 17, a pair of air chambers 18, a pair of slits l9 and a pair of inside walls 20. The compressed air is supplied to the guide pipe 14 in such a way that the compressed air is continuously ejected into a passage defined by the inside walls 20 from the slits 19 through the air chambers 18. Therefore an aspirating action is created at an entrance portion of the guide pipe 14 and the liberated individual fibers are smoothly led into the entrance portion of the guide pipe 14 by the inertia thereof together with the aspirating air stream. Since an-air film, which is created by an ejection of compressed air from the slits 19 which ejected air streams at an angle below 10 with respect to the longitudinal axis of the guide pipe 14, envelopes liberated individual fibers flying in the guide pipe 14, the parallelism of these fibers is maintained while passing through the guide pipe 14. Since the parallelism of the component fibers in the yarn produced by the above-mentioned apparatus is very high, the mechanical properties of the yarn is high enough for practical use, moreover, the wrapping of the liberated fibers about the pullingout rollers is so seldom caused that fly of fibers in the adjacent space to the spinning rotor is prevented and there is no possibility of creating yarn defects such as slubs, and the device can be always maintained in a clean condition.

As already illustrated by other embodiments of the present invention, for example, the embodiment shown in FIG. 3, since the textile fibers are liberated from the continuous bundle of fibers by the drafting action of the pulling-out rollers, it is not required to liberate the individual fibers from the bundle in the guide pipe. It is sufficient to guide the liberated individual fibers flying towards the spinning rotor 5 by enveloping the fibers with the above-mentioned air film so that the parallelism of the individual fibers can be maintained during the above-mentioned carrying of fibers to the collecting surface of the spinning rotor 5. Therefore, as already illustrated, in this embodiment, it is desirable that the length of the guide pipe is shorter than the average fiber length of the individual fibers, and the distance between the nip point of the pulling-out rollers and the collecting surface of the spinning rotor 5 is slightly longer than the average fiber length of the individual fibers of the fiber bundle.

In the above-mentioned embodiment, the compressed air is ejected from both sides of the inside walls 20. However, if a cylindrical slit and a cylindrical inside wall can be used instead of the elements of the above-mentioned embodiment. the group of liberated individual fibers can be fully enveloped by a cylindrical air film and the guide pipe 14 can be operated effectively. Instead of applying the cylindrical slit 19, a plurality of slits that is. at least more than two, can be satisfactorily utilized for the same purpose.

Example 3 An acrylic yarn is spun by the open-end spinning apparatus shown in FIG. 5 under the following condition of Table 7.

TABLE 7 Spinning material Polyiicrylic fiber in denierx I02 mm Mass of individual fiber 10.9 x l0 g Thickness of sliver 5 g/m Cross sectional size of the guide pipe:

Entrance 20 x 20 mm Outlet 15 x 15 mm Pressure of compressed air 0.3 kg/cm Flow rate of the compressed air 15 !/min Spinning speed 70 mlmin Yarn count (metric system) 1/5 To clarify the quality of yarn A produced by the above-mentioned condition, a yarn B for comparison Ts also produced by applying the same conditions except for the stopping of the compressed air supply. The following Table 8 shows this comparison.

As it is clearly shown in the above-mentioned comparison, it is clarified that the guide pipe applied for the aspiration effect by supplying the compressed air, is useful for improving the quality of yarn produced by the open-end spinning apparatus utilizing the pulling-out rollers.

Referring to FIGS. 6A, 68 showing a modification of the apparatus illustrated in FIG. 3, explanations with respect to the pulling-out

rollers

4,4, the spinning rotor 5, the taking-up rollers 11, 11' are omitted, since they have the identical functions as those of the apparatus shown in FIG. 3. In this embodiment, the bundle of fibers l is fed into the drafting zone between the

feed rollers

2, 2 and the pulling-out

rollers

4, 4. The collector 3 is positioned at the drafting zone so as to prevent the dishevelling of the individual fibers passing through the draft zone. The collector 3 is provided with a pair of slits connected to a pressurized air supply source, and the compressed air is ejected from the slits so that a pair of compressed air streams flow into a guide pipe 22 after passing through spaces formed between grooves of the pullingout rollers 4, 4'. Therefore, the liberated individual fibers are led perfectly into the guide pipe 22 without protruding beyond the pulling-out

rollers

4, 4 and the guide pipe 22. The constructions and functions of the collector 3 together with the pulling-out

rollers

4, 4 and the guide pipe 22 are hereinafter illustrated in detail. Referring to FIGS. 6A, 6B, 7 and 8, the individual fibers of the bundle of fibers 1 are liberated by the drafting action of the pulling-out rollers 4, 4', which are provided with a pair of grooves formed at both end portions thereof, respectively, as shown in FIG. 8, while passing through a guide passage 32, which is shown in FIG. 7. The compressed air is fed into a pair of air chambers 33 through conduits 31, respectively, and the compressed air is ejected from slits 34 formed at the outlet portions of the respective air chambers 33 to the above-mentioned grooves 41 of the pulling-out rollers 4, 4'. The pulling-out

rollers

4, 4 are urged together with high pressure so that the desired draft action can be created. Since a pair of spaces are formed by the grooves 41, the ejected air streams are led into the guide pipe 22 in such a way that a group of liberated individual fibers are enveloped in the air stream. Consequently, the liberated individual fibers are fed to the spinning rotor 5.

It is a characteristic feature of the apparatus that the liberated individual fibers, are controlled in their movement by the air stream so that the fibers are led along the above-mentioned passage without any protrusions beyond the pulling-out rollers 4, 4'. There- 'fore, the parallelism between the liberated individual fibers can be always maintained. Since the individual fibers are controlled in their movement by the air stream instead of applying a solid guide, any creation of hooked fibers or flying fibers can be satisfactorily prevented.

By our experiment, the above-mentioned modified apparatus is preferably available for producing yarns from a coarse bundle of fibers or textile material having coarse fineness or long staple length.

Example 4 An acrylic yarn is spun by the open-end spinning apparatus shown in FIGS. 6A, 68 under the following conditions of Table 9.

TABLE 9 Spinning material Polyacrylic fiber 10 denierx 102 mm Mass of the individual fibers 10.9 x 10- g Yarn count (metric system) l/S Weight of sliver 5 glmeter Supplying speed of sliver 2.1 m/min Diameter ofthe pulling-out roller 60 mm Rotation speed of the pulling-out roller 4,000 rpm. Peripheral speed of the pulling-out roller 754 ml min Draft ratio 3 58 Entire width of the pulling-out roller 40 mm Effective width of the pulling-out roller (width within both grooves) 30 mm Width and depth of the groove 2 x 10 mm Pressure of the compressed air 0.3 ltg/cm Flow rate of the compressed air 15 !/min Maximum inside diameter of the spinning rotor mm Rotation speed of the spinning rotor 12,000 rpm. Spinning speed 50 mlmin Cross-sectional size of the guide pipe:

Entrance 20 x 20 mm Outlet 15 x15 mm To clarify the quality of Yarn A produced by the above-mentioned conditions, a Yarn B for comparison is also produced by applying the same conditions except for the stopping of the compressed air supply. The following Table 10 shows this comparison.

TABLE 10 Y am A Yarn B Yarn count (metric system) 1/503 115.03 Number oftwist in T/meter 215 215 Tensile strength in kg 2.02 1.98 Breaking elongation in percent 18.1 Evenness of yarn thickness (U%) 12.8 13.5

- fibers and a spinning rotor, an improvement comprising means for positively extracting individual fibers from said continuous bundle of fibers, said extracting means comprising a pair of pulling-out rollers disposed between said supply means and said spinning rotor, means for running said pulling-out rollers at a sufficiently high speed for pulling-out said individual fibers from said continuous bundle of fibers whereby the inertia of each of said pulled-out fibers impels it at high speed toward an inside portion of said spinning rotor, without disturbing the mutually parallel arrangement of said pulled-out fibers.

2. An improved open-end spinning apparatus according to claim 1, wherein the distance between the nip point of said pulling-out rollers and said inside portion of said spinning rotor is selected to be longer than an average length of said individual fibers.

3. An improved open-end spinning apparatus according to claim 1, further comprising a guide pipe for directing said pulled-out individual fibers to said spinning rotor, said guide pipe disposed between said pulling-out rollers and said spinning rotor, means for supplying air under pressure into said guide pipe so that said liberated individual fibers are carried to said spinning rotor together with an air stream guide pipe is shorter than said average length l of said individual fibers.

4. An improved open-end spinning apparatus according to claim 3, wherein said guide pipe is provided with at least one slit so that said air under pressure is directed along inside surfaces of said guide pipe.

5. An improved open-end spinning apparatus according to claim 1, further comprising means for creating a pair of air streams and applying them on both sides of the nip line of said pulling-out rollers.

6. An improved open-end spinning apparatus according to claim 1, further comprising a guide pipe for leading said pulled-out individual fibers to said spinning rotor, said guide pipe being disposed between said pulling-out rollers and said spinning rotor, said guide pipe provided with an entrance having sufficient size to receive said pair of air streams from said air stream creating means.

Claims

1. A container comprising a body of relatively porous pliable and dust-impermeabLe material defining a chamber, a relatively stiff dust-impermeable end plate member disposed at one end of said body, said end plate member being provided with an inlet aperture for communicating with said chamber, a thin sheet of stretchable elastic dust-impermeable material secured to said end plate member and extending over said inlet aperture, said sheet being provided with an aperture in registry with said inlet aperture, said sheet aperture being smaller than said inlet aperture, said end plate member also being provided with a bridge integral with said end plate member and extending across said inlet aperture, said bridge including means for engagement in said sheet aperture to hold a portion of said bridge against said sheet aperture and to prevent said bridge portion from passing back through said sheet aperture once said bridge portion is originally forced through said sheet aperture, said means for engagement including a bulbous middle section defining said bridge portion, said bulbous middle section being disposed between first and second connecting sections of said bridge which space said bulbous section from said end plate member, said bridge being frangible at a junction line disposed between said bulbous section and said first connecting section, said bulbous section including a width portion larger than adjacent portions of said connecting sections, said bulbous section being larger than said sheet aperture to cover and overlap said sheet aperture with said bulbous section providing a substantially uniform area around said sheet aperture, and said sheet aperture being hooked around said bulbous section once said bulbous section is originally forced through said sheet aperture to seal said sheet aperture and therefore seal said chamber of said container.

2. A container according to claim 1, wherein said sheet aperture is circular.

3. A container according to claim 1, wherein said bulbous section is provided with a circular outline.

4. A container according to claim 1, wherein said first connecting section is provided with a gradually increasing width towards said end plate member to provide a wide fold line between said first connecting section and said end plate member, said first connecting section being narrower at said junction line.

5. A container according to claim 4, wherein said first connecting section defines abuttment means to fix an inlet tube disposed in said inlet aperture in a stationary position relative to said end plate member.

6. A container according to claim 1, wherein a fold line is disposed between said second connecting section and said end plate member, said fold line being spaced from said inlet aperture, a pair of transverse cuts connecting said fold line to said inlet aperture.

7. A container according to claim 6, wherein said fold line is scored straight across the width of said second connecting section.

8. A container according to claim 1, wherein said second connecting section is tapered to provide a narrower portion adjacent to said bulbous section.

9. A container according to claim 8, wherein said tapered second connecting section is gently curved.

10. A container according to claim 8, wherein said narrower portion of said second connecting section is smaller in width than said sheet aperture.