Classifications

• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H4/00—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques
  • D01H4/02—Open-end spinning machines or arrangements for imparting twist to independently moving fibres separated from slivers; Piecing arrangements therefor; Covering endless core threads with fibres by open-end spinning techniques imparting twist by a fluid, e.g. air vortex
• • D—TEXTILES; PAPER
  • D01—NATURAL OR MAN-MADE THREADS OR FIBRES; SPINNING
  • D01H—SPINNING OR TWISTING
  • D01H1/00—Spinning or twisting machines in which the product is wound-up continuously
  • D01H1/11—Spinning by false-twisting
  • D01H1/115—Spinning by false-twisting using pneumatic means

Definitions

• the invention relates to a device according to the preamble of the independent claim.
• the device is used to produce a spun yarn from a loose fiber dressing supplied to the device, the fiber dressing being drawn through a swirl chamber in which the fibers are subjected to a vortex flow of a fluid to impart rotation and are thereby spun into a yarn.
• Spinning devices of the type mentioned above are known, for example, from the publications US-5528895 or US-5647197 (both Murata). Such devices have a fiber feed channel and a yarn take-off channel, the output region of the fiber feed channel being directed essentially against the input area of the yarn take-off channel and the output opening of the fiber feed channel being arranged at a distance from the input opening of the yarn take-off channel. The vortex flow is generated in the area of this distance.
• a swirl stop means e.g., eccentric edge over which the fibers are drawn or a substantially concentric pin around which the fibers are guided
• the entrance area of the yarn take-off channel usually has the shape of a slim spindle, which rotates, if necessary, and which, like the vortex flow, can have a rotation-imparting function.
• a drain channel with an essentially annular cross-section runs around the spindle.
• the drain channel leads from the cavity between the fiber feed channel and the yarn take-off channel and is essentially parallel to the yarn take-off channel.
• the swirl chamber has a diameter that is essentially the same as the entrance area of the drain channel and is equipped with nozzles directed tangentially into the chamber for blowing in a fluid (e.g. air ) equipped.
• the fluid blown into the swirl chamber is discharged through the discharge channel, the swirl flow generated in the swirl chamber continuing around the yarn take-off channel (spindle) into the drain channel.
• the vortex chamber and an entrance area of the Drain channel therefore essentially represent a functional unit that serves to impart rotation.
• the cross sections of the fiber feed channel, yarn take-off channel and drain channel are small compared to an average fiber length.
• the length of the fiber feed channel is designed in such a way that at least some of the fibers, the leading end of which has already reached the area of the yarn take-off channel, are still held in the entrance area of the fiber feed channel (e.g. between delivery rollers of a drafting system connected upstream of the fiber feed channel).
• Fibers which are fed to a device as briefly described above, are held in the fiber structure on the one hand and are thus guided from the exit opening of the fiber feed channel into the yarn take-off channel essentially without giving rotation.
• the fibers in the area between the fiber feed channel and the yarn take-off channel are exposed to the centrifugal effect of the vortex flow, by means of which they or at least their end regions are driven radially away from the inlet opening of the yarn take-off channel.
• the yarns produced with the described method also show a core of fibers or fiber areas running essentially in the longitudinal direction of the yarn without substantial rotation and an outer area in which the fibers or fiber areas are rotated around the core.
• this yarn structure comes about because leading ends of fibers, in particular fibers, the trailing areas of which are still held upstream from the fiber feed channel, essentially reach the yarn withdrawal channel directly, but trailing fiber areas, especially if they are in the entrance area of the Fiber feed channel can no longer be held, pulled out of the fiber structure by the vortex effect and then rotated around the resulting yarn. It can also happen that leading ends of fibers are spread out of the fiber structure by the vortex effect, while the trailing end in the central one The area of the fiber structure remains, which leads to the loops observed in the corresponding yarns.
• fibers are incorporated at the same time in the yarn being formed, as a result of which they are drawn into the yarn take-off channel, and also exposed to the vortex flow, which accelerates them centrifugally, i.e. away from the inlet opening of the yarn take-off channel, and pulls them into the drain channel.
• the fiber areas drawn out of the fiber structure by the vortex flow form a fiber vortex opening into the inlet opening of the yarn take-off channel, the longer portions of which spiral outward around the spindle-shaped input area of the yarn take-off channel and are drawn in this spiral against the force of the flow in the outlet channel against the input opening of the yarn take-off channel , Fibers, the leading or trailing end of which are not drawn into the resulting yarn, are sucked through the drainage channel with a probability that becomes longer with a smaller fiber length and thereby represent undesirable fiber exit.
• the known spinning process described is distinguished by the fact that it allows very high spinning speeds (up to ten times higher spinning speeds than for ring spinning processes). On the other hand, it proves difficult to avoid high fiber loss with the method and to obtain sufficient fiber twist in the twisted outer region of the yarn for high yarn quality.
• the object of the invention is therefore to create a device for spinning by means of vortex flow, with which device it should be possible to achieve higher yarn qualities than is possible with the known devices which serve the same purpose.
• the fiber exit should be as small as possible, which means in any case not larger than is possible with known devices. This object is achieved by the device as defined in the claims.
• the invention is based on the idea of creating more twist by increasing the swirl efficiency in the yarn, the swirl efficiency being increased by reducing the friction between swirling fiber areas and stationary device parts.
• the desired friction reductions are achieved by not guiding a substantial part of the fiber swirl in a frictional manner, as is known, at the radial boundaries of the swirl chamber and around a spindle-shaped entry area of the yarn take-off channel, but on a guide surface that extends around the inlet opening of the yarn take-off channel and around the yarn take-off channel whose axis in the yarn take-off direction forms an angle of more than 30 ° (preferably between 45 ° and 90 °).
• the guide surface thus extends in a collar-like manner around the inlet opening of the yarn take-off channel, its outermost regions being at a distance from the input opening of the yarn take-off channel which corresponds to at least one tenth of the effective stack length of the fibers to be processed and is preferably greater than one sixth of the effective stack length.
• the above-mentioned effective stack length is calculated using the formula published in Japanese Utility Model No. 2.513.582. It is somewhat larger than an average stack length determined with an Almeter.
• the guide surface of the device according to the invention represents a preferably blunt cone, at the tip of which the inlet opening of the yarn take-off channel is arranged. It has no rotation-imparting function, that is to say it does not rotate and is therefore designed for the smallest possible fiber adhesion or fiber friction.
• the improvements in the spinning process with regard to yarn quality and fiber discharge which can be achieved with the device according to the invention in comparison with devices according to the prior art, are based on the following effects:
• the rotating fiber ends, which according to the prior art are around the outside Spindle-shaped yarn take-off channel arranged and tightened screw-like around this spindle by pulling off the yarn are arranged flatter in the device according to the invention, thereby preventing the tightening and associated fiber friction.
• At least a part of the surfaces that radially delimit the fiber vortex, against which the fibers are pressed by the centrifugal force of the vortex flow are further away from the center of the fiber vortex and therefore only generate friction with a smaller proportion of the vortex fibers than is the case in known devices is.
• the friction-reducing effect of the guide surface of the device according to the invention can be increased further if it is given a suitable surface structure (e.g. orange peel) which further reduces fiber friction.
• a suitable surface structure e.g. orange peel
• FIGS. 2 and 3 show the swirl chamber region, likewise shown in section, of two exemplary embodiments of the device according to the invention.
• FIG. 1 shows the swirl chamber area of a device according to the prior art, with which a loose fiber structure 2 fed through a fiber feed channel 1 is given a rotation in a swirl chamber 3, so that a spun yarn 4 is produced, which is drawn off through a yarn withdrawal channel 5 ,
• the vortex flow is stopped in the vortex chamber 3 by blowing in a fluid, e.g. Air generated by nozzles 6 opening tangentially into the chamber.
• a fluid e.g. Air generated by nozzles 6 opening tangentially into the chamber.
• the fluid is discharged through a drain channel 7, the drain channel 7 having an annular cross section arranged around the yarn take-off channel 5 and its entrance area having essentially the same diameter as the swirl chamber 3, so that the swirl flow generated in the swirl chamber continues into the drain channel and Fiber areas 8 detached from the fiber area by the centrifugal effect of the vortex flow lie in the discharge channel in a spiral shape around the stationary or rotating, spindle-shaped entry area of the yarn take-off channel 5.
• the vortex chamber 3 and the inlet area of the drain channel 7 represent a functional unit.
• an edge 10 is arranged at the exit opening 9 of the fiber feed channel 1 as a twist stop means, which edge is arranged eccentrically to the yarn take-off channel 5. It is also known to use a needle (pin) which is arranged essentially concentrically to the yarn take-off channel as the twist-stop means and which needle represents a temporary yarn core.
• the diameter of the swirl chamber 3 and of the inlet area of the discharge channel 7 corresponds to approximately 15 to 20% of the effective stack length of the fibers to be processed. This means that a large part of the fiber regions moving in the fiber vortex 8 rub against the outer walls of the vortex chamber 3 and the discharge channel 5, which are oriented perpendicular to the centrifugal force.
• the swirling fiber areas are increasingly spiraled to the inner wall of the drain channel 7 (outer wall of the Garnabzugkanals 5) created and even tightened like a screw, which in turn creates friction.
• Figure 2 shows a first exemplary embodiment of the device according to the invention.
• the area of the swirl chamber 3 is shown, i.e. the exit area of the fiber feed channel 1 with exit opening 9 and twist stopper 10 and the entry area of the yarn take-off channel 5 with entry opening 11, as well as swirl chamber 3 and discharge channel 7, which, as in FIG has an essentially annular cross section.
• the swirl chamber 3 of the embodiment shown in FIG. 2 has a guide surface 20 which delimits the swirl chamber 3 downstream and which forms an angle ⁇ of at least 30 °, advantageously between 45 to 90 °, with the axis of the yarn take-off channel 5.
• the guide surface 20 extends like a collar around the inlet opening 11 of the yarn outlet channel 5 and forms a preferably blunt cone at the tip of which the inlet opening 11 of the yarn outlet channel 5 is arranged.
• the radial extent of the guide surface 20 is at least as large as a tenth, preferably greater than a sixth, of the effective stack length of the fibers to be processed.
• the drain channel 7 is connected to the outside of the guide surface 20 and, at least in this area, has an annular cross section which is significantly larger than in the prior art.
• the boundary of the swirl chamber 3 upstream preferably runs at least partially approximately parallel to the guide surface 20.
• the guide surface 20 has no rotation-imparting function. This means that it is stationary, as is the yarn take-off channel. The rotation is only given by the vortex flow.
• the nozzles 6, through which a fluid is pressed into the swirl chamber 3 in a tangential direction in order to generate the swirl flow, are advantageously arranged somewhat upstream from the inlet opening 11 of the yarn take-off channel 5 and are regularly distributed around them.
• Your radial position is preferably relatively close to the axis of the yarn take-off channel 5, preferably closer than the radial position of the outermost guide surface areas, as shown in FIG. 2.
• the fiber friction on walls perpendicular to the centrifugal force of the swirl flow is reduced.
• the swirling fiber areas can also no longer be tightened by pulling in the yarn, so that less fiber friction arises on the guide surface than is the case on the slim spindle of the yarn take-off channel of the known devices.
• Fiber friction on the guide surface can be further reduced by providing it with a corresponding surface structure in a manner known per se. As a result of the friction reductions effected in this way, the swirling fiber regions are rotated with greater efficiency than is the case in devices according to the prior art.
• FIG. 3 shows a further exemplary embodiment of the device according to the invention, the type of representation being the same as in FIGS. 1 and 2. The same parts are also designated with the same reference numbers.
• FIG. 3 differs from that of FIG. 2 essentially only by the angle ⁇ , which in this case is 90 °, so that the guide surface 20 is oriented essentially perpendicular to the yarn take-off channel 5.
• the swirl chamber 3 is essentially in the form of a circular disk.
• the radial extent of the guide surface 20 and the angle ⁇ of the guide surface 20 to the axis of the yarn take-off channel 5 and their matching to the vortex flow to be generated can be determined experimentally for different spinning processes, in particular for the spinning of different fiber materials.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Textile Engineering (AREA)
• Spinning Or Twisting Of Yarns (AREA)
• Yarns And Mechanical Finishing Of Yarns Or Ropes (AREA)

Applications Claiming Priority (3)

Publications (2)

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• 2002
  • 2002-08-05 AT AT02748531T patent/ATE347630T1/de not_active IP Right Cessation
  • 2002-08-05 US US10/486,038 patent/US7043893B2/en not_active Expired - Fee Related
  • 2002-08-05 DE DE50208906T patent/DE50208906D1/de not_active Expired - Fee Related
  • 2002-08-05 EP EP02748531A patent/EP1415027B1/fr not_active Expired - Lifetime
  • 2002-08-05 WO PCT/CH2002/000430 patent/WO2003014443A1/fr active IP Right Grant
  • 2002-08-05 CN CNA028198301A patent/CN1564886A/zh active Pending
  • 2002-08-05 JP JP2003519565A patent/JP2004537659A/ja active Pending

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