FR2463212A1 - Multilayer fibre spun yarn - formed by adding surface fibres whilst false twisting core yarn - Google Patents

Abstract

Twisted yarn is false twisted between nips and further fibres are applied to the yarn surface during twisting to form a multilayer twisted yarn. The composite multilayer yarn is formed at high speed without the need for a binder to keep the fibres together. Pref. airborne fibres are fed in a helical airstream to be twisted and laid on a roll. The yarn is nipped by rolls during subsequent false twisting. Additional fibres are fed to the yarn being twisted via duct. The partially finished yarn can be wound up on roll, or further fibres are added and/or core yarn is fed to the twisted yarn on roll. The yarn is held on rolls by internal suction ducts.

Description

The present invention, relating to spinning, relates more specifically to a method and an apparatus for manufacturing yarn.

 One of the limiting factors in producing the yarn at high speeds is twisting the fibers to form a coherent yarn structure while retaining enough twist. In the prior art, it has been consistently held that in order to print and maintain a twist in a strand of yarn made up of sections of fibers, one end of the strand should be able to turn freely. terms, if any attempt is made to impart a twist to a continuous strand of fiber sections which is held fixed at both ends, it will appear a twist to the right on the strand, on one side of the device torsion, which will be counterbalanced by a twist to the left in the strand of the opposite side of the device. As a result, the net twist will be zero, the twists to the right and to the left compensating for each other.

 In order to overcome the above difficulty, it has been proposed in the prior art (1) to rotate the winding (or packaging) gathering the yarn transaxially or (2) to rotate the fiber feed strand to which a discontinuous loose portion is continuously applied.

 The idea of spinning the winding gathering the yarn is commonly known by the name of ring spinning and includes spinning with fins, cap and pot. The idea of rotating the supply of fibers in the strand passing through a rotating pot rotor is usually known by the name of open-end rotor spinning. The transaxial rotation of the wire winding in the ring spinning and the rotor pot in the open end spinning inherently constitute technological limitations in the production of the yarn, as far as fibers, pins and speeds.

 Methods have also been proposed for making "composite" yarns which include two or more layers of yarn forming material in the final yarn produced. The development of these composite yarns has enabled the "industrial production" of desired properties in the yarn produced. Composite yarns are formed using a thermoplastic substance such as a binder for the fibers.

 The manufacture of composite yarns comprising a polymeric material which bonds the fibers together overcomes the numerous technological limitations existing in ring and pot spinning processes. Yarns can be made at speeds hitherto unequaled.

however, for many applications, the textile industry prefers to use yarns with a cut fiber content of 1000/0. These wires must then be manufactured by the ring or pot method.

 The present invention provides methods and apparatus for obtaining a new yarn structure at high speeds, without the need for a thermoplastic substrate to bond the fibers together.

 According to one aspect of the invention, a process suitable for manufacturing a wire is obtained, this process comprising as stages the supply of first fibers, the application of a pretension to said first fibers to form a strand, the circulation or passage of said strand between a first pinch point and a second pinch point and, while said strand is between said pinch points, juxtaposing second fibers with said strand to form a wire.

 According to an advanced aspect of the invention, there is provided an apparatus suitable for manufacturing yarn, the apparatus comprising means for supplying first fibers, means for printing a pre-twist on said first fibers to form a strand with them, means for establishing a first pinch point and a second pinch point through which said strand passes to maintain the pre-formed print on said first fibers and means for juxtaposing second fibers with said strand while said strand is between said first and second points .

 According to another aspect of the present invention, a thread is obtained comprising an inner yarn and an outer layer surrounding said inner core, the latter being formed by first fibers twisted in the direction S, said outer layer being formed by second twisted fibers. in the Z direction.

According to a preferred aspect of the method and embodiment of the apparatus according to the present invention, means are established for twisting the first fibers and the second fibers, said means being in intermediate position between said first pinch point and said second point pinch.

 The fibers used for the implementation of the present invention can consist of any suitable known fiber, either manufactured by man, or natural, including for example cotton, wool, jute, linen, polyesters, etc. .

 The present invention makes it possible to obtain different wire structures which will be explained in more detail later.

Having thus described the invention in general, reference will now be made to the appended drawings which represent, without limitation, several embodiments, drawings in which
- Figure 1 is a side elevation of an apparatus, partly in section;
- Figure 2, a side section of a torsion device;
- Figure 3, a side view, partly in section, for another embodiment of a wire forming apparatus;
- Figure 4, a side view partly in section of a wire forming apparatus according to one / further embodiment;
- Figure 5 is still related to another embodiment of wire forming apparatus and in this figure we see a different device for feeding fibers and another means of twisting the wire;
- Figure 6, a partial cross section of another fiber supply device;
- Figure 6A, a cross section of the tubular fiber supply device (detail) of Figure 6;
FIG. 7 is a top view, partly cut away, of an apparatus according to another embodiment, and
- Figure 8, a side view of an assembled device of modular design.

 The apparatus of FIG. 1 includes a converging member 12 for feeding fibers, which comprises a multiplicity of openings 14 through which a fluid material under pressure (not shown), such as air, is sent, this being indicated by the arrows 16. The first fibers 18 are directed into the interior of the member 12 in the direction indicated by the arrows 20, so that the individual fibers take a vortex flow mode which is their printed by pressurized air passing through the openings 14 which are almost tangent to the walls of the member 12.

The fibers 18 are deposited on the roller 22 pivoting on the shaft 24 and rotated in the direction indicated by the arrow 26. The roller 22 is a suction roller and as such it includes a multiplicity of openings 28 which communicate with the inside of the roller, in which a duct 30 is provided connected to a suitable member serving to create a depression.

In the vicinity of the place where the fibers 18 are deposited on the roller 22, there is a pressure roller 32 pivoting on a shaft 34. The pressure roller 32 is connected via the arm 36 to a support device 38; preferably the pressure roller 32 is biased by a spring device or the like towards the surface of the suction roller 22 and can rotate freely. Thus the pressure roller 32 creates a first pinch point for the strand 42 which comprises fibers 18 partially twisted due to the vortex flow of pressurized air arriving through the openings 14 of the member 42 forming a box.

Downstream of the first pinch point, a multiplicity of second fibers 40 is juxtaposed with the strand 42.

The fibers 40 can be supplied pneumatically from a suitable source of fibers. The combined material or wire 45 thus comprises an inner strand 42 with fibers 40 which are twisted around it.

This combined product then passes against a rotating friction disc 46. The drive means of the friction disc 46 comprise a roller 60 mounted on the shaft 62 which is driven in the direction of the arrow 64 and which is in contact with a edge of the friction disc 46. it follows that the friction disc 46 rotates in the direction indicated by the arrow 48o. In a preferred embodiment, the friction disc 46 is driven at a rotational speed greater than that of the roller. suction 22. The resulting wire is then passed through a guide ring 52 and between guide rollers 54 and 56 to the winding roller 58. The guide rollers 54 and 56 are mounted in mutual juxtaposition and when the wire passes between them a second pinch point is created there.

 The wire formed by the method described above and with such an apparatus may have different constitutions depending on the working conditions of the method and the apparatus.

Thus, in one embodiment of the invention, the arrangement of the openings 14 and the direction of the air under pressure are chosen to impart to the fibers 18, which subsequently form the strand 42, a twist in the direction S. Â In this respect, whatever the direction of the twist printed on the strand 42, this twist is obtained by means of the first pinch point 44 created by the pressure roller 32 applied against the suction roller.

If we consider an individual fiber, the fiber head arriving at pinch point 44 is firmly held there. During this time the fiber tail is free to twist all around fibers held similarly due to the vortex configuration of the pressurized air.

 The strand 42 then presents this pretortion directed in S which is maintained there by creation of the first pinch point 44 and the second pinch point 55.

When the second fibers 40 are juxtaposed with the first layer of fibers and another twist is then impressed in the direction S by the friction disc 46, the result of the twists will be greater than the friction twist that the disc could cause alone . When the twist is in the same direction as the pretortion printed on strand 42, part of the twist will be lost before passing to the second nip between the rollers 54 and 56 and the strand will contain the sum of the original pretortion and the retained twist printed by friction disc 46.

 In another possible embodiment, the twist printed on the strand 42 is in the direction S and that resulting from the friction disc 46 is in the direction Z.

 In this embodiment, the friction disc will create a counter torque and it follows that the final strand will contain an inner core or strand, twisted in the direction S, with an outer layer twisted in the direction Z. Thus the strand will contain the amount of twist imprinted by the friction disc 46 with the slip of the fibers minus the pretorsion imprinted to the inner layer 42. This will thus provide a yarn having double or reverse twist simulating an aspect of yarn with multiple strands twisted together. The twisting of this thread can no longer be redone in itself, since any attempt to untwist in one direction will only result in tightening the twist in the other direction.

To obtain the above results, the apparatus may further be modified so that the drive means 60 for rotating the friction disc 46 is a reversible drive means. So we can use the same box member 12 in both embodiments and adapt it to always print a pre-twisted thread in a certain direction, i.e. in the direction
S or Z, the friction disc 46 being capable of having a reversible rotation to produce a wire twisted only in one direction or a wire having an alternating or double twist.

 The embodiment of Figure 1 has been described assuming the use of a friction disc 46 at high speed; specialists will understand that in this embodiment any means of false twist can be used. In addition, as has been explained previously, the means of false twist can be eliminated, which means that a double or reverse twist yarn would also be obtained.

 In the above embodiment as well as in the subsequent embodiments, those skilled in the art will understand that suitable fluids can be used to supply the fibers. A preferred fluid will be a pressurized gaseous material such as air; if desired, certain materials can be added to the pressurized fluid to impart certain desired properties to the fibers. The apparatus can be constructed in modular form, with which, for example, a multiplicity of members 12 can be provided which have different characteristics for various fibers.

 Figure 3 shows a basic device, as described with reference to Figure 1, including many optional features.

 In more detail, the first fibers 702 are brought to a chamber 706 as indicated by the arrows 704; the chamber 706 has a multiplicity of openings tangent to the walls through which a gaseous material under pressure passes through the conduit 710.

 The fibers 702 thus have a pretorsion which is printed on them by forming a strand, after which they are deposited on a grooved suction roller 712 which pivots on the shaft 714 rotating in the direction of the arrow 716. A suction chamber 718 to which a suction duct 730 is functionally connected holds the fibers on the suction roller 712 by means of openings 720.

At the place of deposit of the first fibers 702 on the suction roller 712 a pressure roller 722 rotating in the direction of the arrow 726 exerts a pressure on the fibers as indicated by the arrow 724 to form a strand 728 having a contention maintained there.

During the circulation of the strand 728 on the suction roller 712, second fibers 734 introduced through the chamber 732 are juxtaposed with the strand. The resulting strand 736 can then be brought to pass through a torsion device 738 driven by the belt 740 and leaves it in the form of a twisted strand 742 which then passes between a pair of rollers 744 and 746 to a roll of winding 748. Roll 746 is biased against the roll 744 as indicated by arrow 747.

 According to another possible solution, the strand 736 can follow the path indicated by the reference 750 and pass through a torsion device 752 which will be described in more detail below. The twisted strand 754 will then be wound onto the winding roller 748.

In yet another embodiment, the wires 736 or else 754 are placed on another suction roller 756 pivoting on the shaft 758 and driven in rotation in the direction of the arrow 760. The suction roller 756 has a multiplicity of openings 762 and a suction is created by the conduit 764.

 In the embodiment shown, third fibers 768 are caused to pass through the chamber 766 and placed in juxtaposition with the wire on the suction roller 756. Another pressure roller 770 is mounted in juxtaposition with the wire, the roller 770 rotating in the direction of arrow 774 and pivoting against the wire as indicated by arrow 772. The resulting consolidated wire 776 can be wound in a winding or bundle 780 driven in rotation as indicated by arrow 778. Naturally it will be understood that another twist can be made on the three-fiber strand.

 According to other possible embodiments, a continuous filament or carrier 782 passes through one guide ring 784 and is applied to the suction roller 712 before depositing the first fibers 702.

Furthermore, a carrier material 786 can be supplied by a guide 792 to the suction roller 756. As shown in FIG. 3, the carrier 786 can comprise a twisted wire 788 or else a multiplicity of filaments 790 or a multiplicity of bands.

As seen from the above, more than two sources of fiber can be used to make the yarn of the present invention. If desired, after the deposition of each new fiber, the yarn can be twisted, preferably in alternating directions. Also any number of fiber sources can be used with or without an intermediate twist operation.

 Referring now to FIG. 4, there is seen there an apparatus suitable for the manufacture of a composite wire incorporating the principles set out with reference to FIG. 1.

In more detail, the apparatus includes an outer plate or cover 110 which is hingedly connected to the chassis F of the apparatus by means of hinges 112.

The means for blocking the cover plate 110 on the chassis comprise a multiplicity of rotating blocking bars 114.

 An arm 116 fixed to the frame is biased by a spring 118 which contains an opening 120 inside. Fibrous material (not shown) is brought as indicated by the arrow 122 to a feed roller 124 driven to turn in the direction indicated by arrow 126.

 Juxtaposed with the feed roller 124, is mounted an aperture roller or food roller 128 pivoting on the shaft 130 and driven in rotation in the direction of the arrow 132. The circumferential surface of the feed roller 128 includes a plurality of openings 134 communicating with the interior of the roller; the aperture roller 128 also includes a multiplicity of needles or teeth 136 mounted on the circumferential surface. Inside the roller 128, a conduit 138 has been mounted which is adapted to supply a gaseous material under pressure to evacuate the fibers from the surface of the roller as will be exposed. In this regard, the aperture roller 128, in combination with the supply roller 124, is suitable for drawing, combing and making the fibers of the fibrous material practically parallel. It will be understood that any conventional type of roller can be used. openings known to the specialist.

 Inside the frame F there is provided a fiber discharge duct 140; when the fibers pass over the portion into which the gaseous material under pressure coming from the conduit 138 is sent, they are directed by the fiber evacuation conduit 140 as indicated by the arrow 142. The conduit 140 communicates with another internal conduit 144 which acts to print a pretension to fibers as will be described in more detail.

 A fluid supply duct 146 is functionally mounted, being connected to a source of gaseous pressurized material which is then evacuated via duct 144. The gaseous pressurized material is sent into a convergent member 152, frustoconical in the 'assembly, which has a multiplicity of slots or openings 150 formed in a disc 148. These openings or slots 150 are inclined or spiraled so as to impart the desired configuration, in a spiral or in a vortex, to the gaseous material under pressure, as indicated schematically by the arrow. As will be understood, the fibers discharged from the aperture roller 128 through the duct 140 will thus have a spiral or vortex configuration which is imparted to them by the vortex flow of the fluid.

 In the embodiment shown in FIG. 4, the apparatus comprises another conduit 158 connected to a source of gaseous material under pressure (which may be the same as that supplied to conduit 146) and which is sent to another disc 160 having a multiplicity of openings 162 to reinforce the vortex or spiral conformation taken by the fibers. As will be understood by specialists, one or more sources of gaseous material under pressure can be used depending on the length of the path of the fibers and their type.

The apparatus also comprises a suction roller 164 pivoting on the shaft 168 which rotates in the direction indicated by the arrow 170. As can be seen in FIG. 4, the suction roller 164 comprises an interior portion or cavity 172, limited by the surface of the suction roller and the plate 176, which is subjected to a vacuum or to a pressure difference through the conduit 178.

This pressure difference acts effectively to retain the fibers inside the groove of the suction roller when air is sucked in through the openings 174.

 A pressure roller 184 is mounted to interact with the groove on the suction roller 164 and, as can be seen in Figure 4, the pressure roller is mounted by the shaft 186 on an arm 180 which in turn pivots on the shaft 182. The pressure roller 184 rotates freely and applies pressure to the fibers in the groove and for this purpose it can be biased against them by a spring. In addition, the arrangement shown makes it possible to lift the roller 184 or to move it aside when desired.

Thus, as can be seen from the above description, the fibrous material 122 passes through the feed roller 124 into the aperture roller 128 which pulls and combs the fibrous material to form a multiplicity of fibers. These fibers are then evacuated through the conduit 140, and have a vortex or spiral conformation which is communicated to them in the conduit 144 by the vortex flow of the gaseous material under pressure. These fibers are then deposited in the groove of the suction roller 164 and progress there beyond the pressure roller 184.

These -1bre will have the pretortion communicated to them. Thus for example, when the fibers arrive at the point of juxtaposition of the pressure roller 184 with the groove of the suction roller 164, the wtete "or initial part of the fiber is kept in a fixed position, while the" tail "or other end of the fiber will still be subjected to the forces of gaseous material under pressure. As can be seen, the tail end of the fiber will then twist around other fibers, causing it to twist in the strand formed by the fibers.

 As has been explained with reference to FIG. 1, second fibers are then placed in juxtaposition with the strand formed by the first source of fibers. Conveniently, the second source of fibers can be drawn from a source of fibrous material such as that shown in FIG. 4.

 To this end, the apparatus can include a fibration assembly including the arm 200 spring-loaded 202, on the chassis F. The fibrous material 188 passes through the opening 208 towards the feed roller 204 rotating in the direction of the arrow 206.

 The fibrous material 188 arrives at the aperture roller 210 which pivots on the shaft 212 and which is rotated in the direction of the arrow 214 The aperture roller 210, similarly to the aperture roller 128, includes a multiplicity of needles or of teeth 216 mounted on its circumferential surface and further includes openings 218 communicating the surface and the interior of the roller 210.

 Inside the opening roller 210 is mounted a conduit 222 communicating with an internal chamber 224 defined by the walls 220. The conduit 222 is connected to a source of pressurized gaseous material which will evacuate the fibers of the opening roller 210 up to to the strand previously formed by fibers on the suction roller 164. Thus forming a wire comprising an inner strand formed of pre-twisted fibers with an outer layer of fibers.

 In the embodiment of the apparatus which is shown, a friction disc 228 is driven to rotate in the direction of the arrow 230. It is convenient that the friction disc 228 can be further driven by a drive roller 232 as indicated by arrow 234. The resulting wire will then pass through an opening 226 in the housing surrounding the suction roller 164, which serves to "guide" the wire and to hold it against the friction disc 228. Preferably the friction disc 228 rotates at a high peripheral speed (even higher than that of the suction roller 164) and will thus give a twist to the composite wire by the effect of the friction between the wire and the disc.

 Optionally, as shown in Figure 4, the wire can then undergo another operation to provide the desired properties to the final wire. Thus, there is shown a device generally designated by / reference 236, having a central bore 238 all along. Towards the end of the bore 238 is a conduit 240 connected to a source of pressurized gaseous material. The central or intermediate part of the bore 238 is shaped so as to impart a vortex movement to the gaseous material which will then exit through the opening or the conduit 242. The part of the bore 238 having a spiral conformation so as to give the desired configuration of the gaseous material can produce this result by a number of suitable means. Thus the device 236 can have the bore initially formed with the spiral conformation or it can comprise a cylindrical opening comprising a wire or an analogous part, wound in a helix, inserted inside.

 The wire then passes between a pair of rotating rollers 244 and 252 pivoting on respective shafts 246 and 254 and rotating in the direction of the arrows 250 and 256. The wire passes to the location of the clamping of the rollers 244 and 252 thereby forming a second pinch point, the first being that existing between the pressure roller 184 and the groove of the suction roller 164.

The wire can then be wound on a suitable winding or receiving package, indicated by the reference 258.

In the process of the present invention, with reference to the embodiment of FIG. 4, the fibrous material 122 is formed in a multiplicity of discrete fibers by the roller with openings 128. These fibers are then evacuated through the conduit 140 and have a spiral or vortex conformation which is given to them by sending a gaseous material of the same shape. These fibers are then deposited on a suction roller and the creation of a pinch point at the same time as the vortex conformation will form a strand of fibers having a certain artificial twist.

The second source of fibers is formed from a fibrous material 188 by the roller with openings 210 and is placed in juxtaposition with the first strand of pre-twisted fibers. The resulting combined material is then subjected to a friction twist which may exist in the same direction as the pretortion imparted to the inner layer or primary source of fibers or else in the opposite direction. By passing through the device 236, all the ends of liche fibers starting from the outer layer or second fibers will be wrapped in a helix around the strand. The second nip, which allows the above mentioned operation to be carried out, can be conveniently formed by a pair of rollers in the nip of which the wire passes.

 Referring to Figure 2, there is another embodiment of a torsion device which can be used for the implementation of the present invention. This torsion device is generally designated by the rotor 300 and, as can be seen, it is a friction pin through which the composite wire will pass. Passing through the wire is kept under a certain tension by suitable guiding means or the like, so that the wire will be in continuous contact with a friction surface 302. In order to pocket a jam and to create an effect smooth twisting of the wire, the friction surface has a concave portion 304 which is inserted in the center of the friction sleeve 306. The friction pin can also be driven in rotation by a drive belt 309, as indicated by the arrow 308 .

Referring to Figure 5, there is shown another embodiment of a wire forming apparatus. In this illustrated embodiment, the fibrous material is brought by the feed roller 310 to an aperture roller 312 which can be constructed as shown with reference to FIG. 4. The combed and drawn fibers are then removed (from preferably by pneumatic means) as indicated by the arrow 316 in an internal chamber 330 in the casings F. Also inside the frame P there is a first cavity 318 having a conduit 320 which brings it gaseous material under pressure . This pressurized gaseous material exits through openings or orifices 322 in a spiral form. Similarly, a second cavity 324 has a conduit 326 connected to a source of pressurized gaseous material which in turn pours through openings 328 under the desired spiral conformation.

As will be noted, the chamber 33 is convergent in the direction of circulation of the fibers.

 your fibers, having the vortex conformation, are evacuated on a grooved suction roller 314 in the vicinity of a juxtaposition point with a pressure roller 322. The first fibers thus deposited will have the desired pretortion which will be a fairly loose twist.

 Then, the fibrous material supplied by the feed roller 336 to the aperture roller 338 will be juxtaposed with the pre-twisted strand of the first fibers. Then the composite material can undergo a twisting operation as illustrated.

 In one embodiment, a friction pin sleeve 340 can be used. Such a device is well known in the art and need not be explained in detail here.

 According to another solution, a modified magnetic pin torsion device can be used, generally designated by the reference 342. In this embodiment, the torsion device includes an annular disc 344 operatively connected to a source of aspiration or means therefor. The torsion device includes an inner tube or conduit 346 through which the composite material passes; inside the tube 346 there are a multiplicity of slots 348 through which a suction force is applied to exert suction on the composite material thereby winding the outer fibers around the inner layer or core. This will happen until the amount of twist in the wire passing through the twist is amplified. The wire can then pass through the nip of a pair of rotating rollers 350 and 352 which form the second nip. process and device.

 Figure 6 shows yet another embodiment of the apparatus which will now be discussed.

 The apparatus includes a feed roller 400 by means of which a source of fibrous material feeds the opening roller 402 having a multiplicity of teeth 412 and containing openings 410. An internal cavity 404 is formed between the circumferential surface and the limiting plate 406 and in this cavity there is a conduit 408 which brings it gaseous material under pressure.

 The fibers, which are combed and drawn by the roller with openings 402, are removed therefrom after having been combed and drawn by the gaseous material coming from the conduit 408. The fibers are removed in a converging chamber 414 incorporated in the feed F. the fibers Then enter a vortex tube 416 at point 426. The vortex tube 416, as shown in FIG. 6A, has a mouth portion 418 which converges to an internal passage 420 axially passing through the tube. The interior surface around the passage 420 is helically formed by the use of grooves 422.

The vortex tube 416 also includes a converging discharge part, generally designated by the reference 424.

Inside the chassis is mounted a pressurized gas supply conduit 428 which supplies pressurized gaseous material to the vortex tube 416 through openings 430 therein. As seen in the figure, the discharge part 424 is placed in close proximity to a fiber receiving roller 440 which has the shape of a suction roller having openings 442 communicating with a cavity 432, which fact that a pressure difference is created by conduit 444.

Also a pressure roller 434 is mounted in close proximity to the fiber discharge point by pivoting on the shaft 438 and being spring loaded against the grooved suction roller and supported by the arm 436. A first is thus obtained pinch point 452, which means that the fibers are pre-twisted in the manner described with reference to FIGS. 1 and 3.

 The apparatus shown also includes another feed roller 448 and an aperture roller 450 for producing a source of second fibers which are then placed in juxtaposition of the strand formed by the first fibers. The composite material then passes through a torsion device 454 similar to that shown in FIG. 3.

 The vortex tube 416 forming a whole can be an interchangeable element. As has been explained, the inner surface of the vortex tube 416 resembles a threaded conformation comprising a multiplicity of grooves 422, the openings or orifices 430 of which the gaseous material is sent are located at the bottom of each "thread". As will be understood, the high compression forces of the gaseous material under pressure, as well as the helical arrangement of the grooves 422, compact the fibers and confer a soft-structure on the pre-twisted strand supplied. It is desirable that the outlet or flow portion 424 of the tube 416 be shaped to fit the surface of the suction roller which will absorb the flow of air from the tube.

 Thanks to the tube 416, the device of FIG. 6 described above forces the fibers entering the grooved cavities in the form of a screw to take a rotating helical shape which gives a twist under the continuous and high pressure forces of the gaseous material. compressed. This gas or air, as has been explained on the occasion of the previous embodiments, can have a jet configuration to obtain a texturing effect on the fibers and thus act on the yarn during formation.

Furthermore, the pressurized gaseous material can be suitably moistened or otherwise modified, so as to have a desired effect on the fibers.

 The helix angle inside the tube 416 can be modified depending on the fibers used and the yarn produced. Thus it can be more or less stiff and the conformation of the groove notches can be with stiff or obtuse walls depending on the operating parameters of the process.

 The arrangement shown in Figure 6 has several new features and the apparatus shown is capable of forming a range of "types" of wires. Thus, for example, the roller with openings 402 has teeth 412 and an internal duct 460 is provided which provides suction to the surface of the roller by openings 410. Thus the materials supplied by the feed roller 400 are "drawn" by making closer engagement in the teeth. The suction provided can also aid in the cooling and removal of impurities from the material at this suction point. The arrangement is designed to receive not only cut fiber material, but also to produce conversion, into forming material wire, all kinds of plastic tapes or films, metal sheets, paper materials, textile fabrics, etc. All these materials, among others, can be ratcheted in the form of fibers and used as material for the wire formation. Thus a conventional fibrous material such as that schematically indicated by the reference 462 as well as the other materials mentioned above, designated by the reference 465, can feed the roller with openings 402.

 As seen in Figure 6 below, the roller with openings 402 can take different forms.

Thus, as shown, the roller with openings 402 consists of a set of very thin and force-cut metal discs 464 which have teeth 412. The discs 464 have the teeth 412 at their periphery and are stacked with pieces of spacing 466 between the discs, which means that the relative axial positions of the projections of the teeth can be aligned or present any desired design, or else discarded at random. The teeth 412 on the discs 464 can be cut to any desired shape or conformation including symmetrical angles, acute or obtuse angles, tilting towards the front or the rear, etc. In addition, in the axial plane each of the teeth 412 can be bent in any desired direction such as that known in the conventional arrangement of a "saw" where they are slightly offset from each other. The thickness of the discs can be chosen according to the materials used. If desired, the thickness of the disks 464 can be varied in a roller with any openings, that is to say that it can include several thicknesses at various positions along the axis with respect to the others, for example those that can be obtained by having a dis that on two or on three different thickness compared to neighboring disks. In addition disks 464 can be shaped so as to create slots having any shape or dimension desired in cross section, slots through which pressurized air can pass from inside the roller or from duct 408.

Depending on the density of the teeth 412 and their arrangement, the standard length produced by the roller with openings 402 can be adjusted so that the fibers used in the apparatus can be placed with offset relative to each other. This can be further aided by an oscillating mechanism by which the roller 402 oscillates in a direction parallel to its axis of rotation. Thus, as indicated by the reference 468, a combination of spindle and cam can produce the desired movement. it is obvious that any other mechanical arrangement known to the specialist can be used to play a similar role.

Also as shown in FIG. 6, the supply roller 448 can supply wicks of conventional cut fibers 470 to the roll of openings 450, which is a roll having openings 472. The fibers can be removed using a gaseous material under pressure provided by conduit 474 if desired. According to another possibility, the fibers can be released using a sufficiently high peripheral speed of the roller with apertures 450.

Another device 476 can be used in the present invention to obtain various constitutions of the wire. Aingi device 476 can include a dis
positive antrusion positive analog or molten polymer supply tubing. In the case of the device of the extruder type, pellets of a polymeric material can be supplied to a hopper 478 and a matrix nozzle 480 concentrates its nip in the zone of formation of the wire at the outlet of the tube 416 which is located just before the first pinch point created by the pressure roller 434. The extruder 476 can operate in several possible ways. Basically the device 476 can operate in such a way as to finely subdivide the polymeric material having, for example, the shape of fibroid elements and introducing these into the zone of formation of the wire. By doing this one can add any desired polymeric material to the wire and greatly increase the strength.

 The apparatus can also incorporate a source of filamentary material 482 which is conveyed in the form of a filament 484 through the center of the vortex tube 416. The filament 484 can be of any desired material.

 As indicated above, the wire once formed can pass through a suitable twisting device 454. Many other possible pins can be used instead of the one specifically shown including for example rolls with multiple coating cups or pinch rollers, multiple V-grooved rollers, etc. After the twisting operation, the second pinch point is created by passing the composite wire between a pair of rollers 486 and 4US, after which a bundle or winding of wire 490.

 It has been found that by using the apparatus described above, a "tight" pre-twist can be imparted to the first fibers. In this respect it would be particularly suitable for forming a wire without using the optional torsion device 454.

 FIG. 7 shows yet another embodiment of an apparatus forming a composite wire and reference will now be made to this last figure.

 The apparatus shown includes a feed roller 500 and a first aperture roller 502. In the vicinity of the aperture roller 502 is mounted a grooved suction roller 504 which has, as can be seen in Figure 7, a groove 506 offset from the central axis of the aperture roller 502. Thanks to the offset position of the groove 506, the fibers which are extracted from the aperture roller 502 and deposited on the roller 5o4 are forced to move one side to assemble in the groove 506. In addition, the wire formed in the groove 506 will be in close proximity to a rotating friction disc as will be explained in more detail later. Another advantage of the offset arrangement of the groove is that this latter allows the installation of baffles or sealing plates to create a closed chamber and a controlled air flow thereby preventing the formation of down and containing and reducing any possibility of detar fibers moving outside the system.

 A second feed roller 510 supplies fibrous material to a second aperture roller 508 which is shown in cross section. The aperture roller 508, as has been discussed for the previous aperture rollers, has apertures and a multiplicity of needles or teeth 512 at its circumferential surface. As can be seen, a first conduit 514 applies a suction force to a part of the roller with openings 508, while another conduit 516 is connected to a source of gaseous material under pressure to evacuate the fibers of the roller with openings.

Below the suction roller 504 a friction disc 518 similar to that described with reference to FIG. 2 is mounted. The friction disc 518 can be ests tolJsl; mate: solid fiatl or coated with any preferred surface material desirable to obtain good contact of the wire by using abrasion resistant surfaces, having a suitable friction factor. As can be seen, the friction disc 518 has a curved shape of revolution in order to obtain better contact between the wire and the surface and to create twist differences between the approach side and the contact of the wire on the output side with the torsion element.

If desired, the friction disc can be heated or cooled by internal means depending on the quality of wire that is to be formed.

 Figure 7 also illustrates how the various parts of the apparatus can be constructed so that they can be easily disassembled and removed. Thus the suction roller 504 can be mounted on a bearing pin arrangement 520, designed so as to form a removable cartridge assembly. In other words the suction roller 504 can be removed by undoing a suitable screwed fastener 522, then the cartridge 520 can be removed from the rear by undoing the bolts -524. The aperture rollers 502 and 508 can be constructed in a similar manner.

 Figure 8 is a side view of the apparatus having four spinning positions. In this embodiment there is a central module 610 which can include, the central drive and the auxiliary equipment, including the power supply and drive controls under vacuum and under pressure of the various elements of the machine.

As has been said, four spinning positions 620, 630, 640 and 650 have been provided. For each spinning position there is a suitable twisting device, that is to say 632, 642, and means winding 634, 644.

 The feeding of the wick material is designated by the references 600 and 602 and, as can be seen, the wick material can pass through respective wick guide mechanisms 606 and 604. The control indicators and the actuation panels can be conveniently mounted on the top of the device as indicated by. reference 660.

 It will be understood that modifications can be made to the embodiments described above.

Thus, for example in FIG. 4, the disc 148 may comprise an internal tubular part 154 passing through it, which receives a carrier material. In this embodiment, the fibers coming from the roller with openings 128 are then pre-twisted around an internal vehicle, with the second source of fibers also twisted all around in the same direction as the first or in opposite directions.

 According to yet another solution, the internal vehicle can be a thermoplastic polymer material which passes through a heating zone to make it sticky and improve the retention of torsion when the first figures are deposited thereon.

 Also the internal carrier can pass through an extruder so that a thermoplastic polymeric material is deposited thereon.

 Thus, according to these various embodiments, there may be different possibilities, for example a composite yarn formed from an inner layer of fibers twisted in the direction S with an outer layer of fibers also twisted in the direction S. In a second embodiment the inner layer of fibers can have a direction twist S and the outer fibers, a direction twist Z. Using a carrier carrier can have an inner thickness with a first layer of fife having a direction twist S same as a second; alternatively the first layer may have a direction twist S and the second, a direction twist Z.

In yet another embodiment, the application of a sticky thermoplastic polymer material will form a wire having an internal carrier and a "sheath" of polymer material, the first fibers of which are inserted therein have a twist in the direction S and a second layer of fibers which do not adhere to the thermoplastic material, but have a real twist, either in the same direction as the first layer, or in the opposite direction. The fibrous material of the fibers is not in particles; the first and second fibers can be made of the same material, or of different materials. Preferably the first fibers are relatively long cut fibers and the second fibers, relatively short cut fibers.

Claims (26)

RiVETDICATIûN8  1. A method suitable for the manufacture of yarn, comprising as stages: the feeding of first fibers, the communication of a pretortion to said first fibers to form a strand, the running of said strand between a first pinch point and a second point of nipping, and while said strand is between said first and second nipping point, juxtaposing second fibers with said strand to form wire.  2. Method according to claim 1, including the stage of twisting said wire when it is between said first and second pinch points.  3. Method according to claim 2, in which the stage of communication of a pretortion to said first fibers comprises that of the aerodynamic constraint of said fibers to make them take a vortex conformation. 4. The method as claimed in claim 3, in which the stage of flow of a source of first fibers comprises the stage of feeding a non-particulate fibrous material, drawing and combing said fibrous material to form fibers and the present a tion of said fibers in a flow of gaseous material under pressure having a vortex conformation.  5. The method of claim 4, wherein the step of juxtaposing said second fibers to said strand comprises the step of cutting a non-particulate fibrous material, drawing and combing said fibrous material to form fibers and sending said fibers in juxtaposition with said strand.  6. The method of claim 1, wherein the stage of the attachment of a pretortion to said first fibers includes that of the flow of a gaseous material under pressure, having a vortex conformation, sending said fibers into said material flow. gaseous under pressure, the evacuation of said fibers on a movable collecting surface to form a layer thereof and the creation of a first pinch point in the vicinity of the place where said first fibers are evacuated on said movable surface.  7. The method of claim 1, wherein said second fibers are sent pneumatically in juxtaposition with said strand of the first free in a direction co-1cotuaìe le loìg Ce the direction of movement of said layer of the first fibers.  8. The method of claim 1, wherein said second fibers are sent pneumatically in juxtaposition with said strand formed by the first fibers in a direction substantially against the current relative to the direction of movement of the strand of the first fibers.  9. The method of claim 1, wherein said second fibers are sent pneumatically in juxtaposition with said strand formed by first fibers in a direction substantially perpendicular to the direction of movement of said strand.  10. The method of claim 2, wherein the stage of twisting said wire comprises the stage of false twisting of said wire. 11. The method of claim 10, wherein the twisting stage of said yarn comprises that of twisting the yarn in the same direction as the pretorsion printed on said first fibers. 12. The method of claim 10, wherein the twisting stage of said yarn comprises that of twisting the yarn in a direction opposite to the direction of pretorsion printed on the first fibers. 13. The method of claim 1, further comprising the step of providing a continuous filament of a yarn material around which first fibers are pre-twisted.  14. The method of claim 1, including the step of subjecting said wire to a final twist stage after leaving the second pinch point. 15. Apparatus suitable for manufacturing yarn, the apparatus comprising means for pre-twisting first fibers to form a strand therewith, means forming a first nip and a second nip through which passes said strand to maintain the pretortion assigned to said first fibers and means for juxtaposing second fibers with said strand while the latter is located between said first and second pinch points to form the wire.  16. Apparatus according to claim 15, including means - for imparting another twist to said wire while it is between said first and second nip points.  17. Apparatus according to claim 15, in which said means for assigning a pre-twist to said first fibers comprises a fiber flow device, through which said first fibers pass, comprising means for directing a source of gaseous pressure material according to a conformation of Vortex,  18. The apparatus of claim 15, including means for providing a continuous filament of a wire-forming material around which said first fibers are twisted.  19. Apparatus according to claim 15, including a rotating suction roller on which said first. fibers are deposited and a pressure roller in juxtaposition with said suction roller to create said first pinch point.  20. The apparatus of claim 15, wherein said means for juxtaposing said second fibers includes means for pneumatically sending said second fibers in a concurrent direction along the direction of flow of said strand.  21. Apparatus according to claim 15, including means for sending a source of gaseous material under pressure counter-current to the direction of movement of the wire, said means being located between said nip points. 22. Yarn, comprising an inner core and an outer layer around said inner core, said inner core being formed of first fibers twisted in the S direction, said outer layer being formed of second fibers twisted in the direction Z. 23. The wire of claim 22, wherein said inner amAe comprises a filament whose said first fibers are twisted all around.  24. The wire of claim 22, wherein said first and second fibers are made of different materials.  25. The yarn according to claim 22, wherein said first and second fibers are made of the same material.  26. The thread of claim 22, wherein said first fibers are relatively long cut fibers and said second fibers, relatively short cut fibers.