Patent Application
20230287606
The invention relates to an interlacing nozzle for the production of knotted yarns, interlaced yarn, of DTY or plain yarns with knots, and a method for interlacing yarn with the features of the generic term of the independent patent claims.
Various jet devices are known from the prior art. Nozzle devices are commonly used for directing, accelerating and precisely applying fluids. By fluids are meant both gases and liquids. Nozzle devices are used, among other things, in textile machines to join, structure or treat yarns. The shape of the chamber in which the yarn treatment is carried out is decisive for achieving the desired result and the amount of fluid required for this.
In known so-called interlacing nozzles, the treatment chamber usually comprises an air twist chamber into which the fluid flow is introduced and swirled. To achieve sufficient swirling, high velocities are required. This is achieved by blowing air into the chamber at high pressure.
Interlacing nozzles are used to treat all kinds of threads, yarns, cables or similar materials. These can be made of artificial fibers (plastics such as PE, PP, etc.). They can also be made of natural fibers (cotton, wool, raffia, etc.) or mixed fibers. Herein, the term “yarn” is used to refer to all of these types of materials.
Interlacing nozzles are essentially used to interlace yarns made of man-made fibers. Interlacing has several advantages. For example, package build, payoff characteristics, process running properties or running characteristics in downstream processing are improved. Filament breaks are prevented. Pushed-up filaments or fluff can be bound in. In addition, the sizing application can be reduced or weaving without sizing can be made possible. Twisting/up-twisting can be replaced. Interlacing also makes it possible to combine different yarns with different properties or to produce fancy yarns.
From U.S. Pat. No. 5,809,761 a nozzle device is known, which comprises a splicing chamber with two lateral chamber regions. In this nozzle, the yarns do not move. It is not suitable for interlacing.
It is an object of the invention to remedy these and other disadvantages of the prior art. In particular, a nozzle device is to be provided which has a high efficiency and ensures reliable yarn treatment. In particular, the invention is intended to allow a desired knot thickness and/or knot count of a yarn to be achieved, with the lowest possible air pressure and air quantity and correspondingly low energy requirements.
These tasks are solved by an interlacing nozzle for the production of knotted yarns, interlaced yarn of DTY or plain yarns with knots and a method for interlacing yarn according to the characterizing part of the independent claims.
The interlacing nozzle according to the invention comprises a yarn channel with an air twist chamber. The air twist chamber has an injection opening for introducing air into the air twist chamber. A channel axis extends in a yarn guiding direction. The yarn channel has a channel width transverse to the channel axis.
The air twist chamber has a chamber length in a yarn guiding direction and a chamber extent transverse to said length. The chamber length is at least 180% of the chamber extension, preferably at least 200%.
Surprisingly, it has been found that by selectively choosing the shape and dimension of the chamber, the knot count and/or quality can be controlled.
Typically, as described below, the chamber length, the shape or proportions of the cross-section of an injection opening, the chamber expansion, or the angle of chamber walls relative to the wall of the yarn channel can be selectively adjusted individually or in combination to set a desired knot count and/or quality.
For example, a chamber length (relative to the chamber extension) of between 210% and 230%, in particular about 220%, leads to the formation of fewer but more stable knots. A length of between 320% and 340%, in particular about 330% leads to many but less stable nodes . . . . The chamber length is preferably at least 1.5 mm longer than the chamber extension. A further aspect of the invention therefore relates to a method for adjusting the number and/or quality of knots, in which the shape and dimension of the chamber is specifically selected for defining the number and/or quality of knots, In particular, a chamber length is selected relative to the chamber extent, wherein a shorter length is selected for forming a few but more stable knots and a greater length is selected for forming more but therefore less stable knots. In any case, the lengths are more than 180% of the chamber extension and are preferably selected as described above.
The air flow vectors (flow direction and strength of the air flow) within the air twist chamber, in conjunction with the overhang, are decisive for the number and strength of the nodes. The overfeed indicates how much more yarn length is introduced into the nozzle than comes out of the nozzle. This excess is used for knot formation. Different components of the air flow vectors lead to different effects when treating yarn in interlacing nozzles: Components of the air flow vectors, which are directed in yarn guiding direction or the opposite direction to it, influence yarn feed and yarn tension. Components of the air flow vectors which lead transversely to these directions interlace the yarn and are thus essential for knot formation. The inventors have come to the conclusion that, in order to achieve optimum treatment, the air flow in the air twist chamber should be directed in such a way that the air flow has more transverse components than components in the yarn guiding direction or in the opposite direction to the yarn guiding direction. Outside the air twist chamber, on the other hand, the air flow vectors should have more components in yarn guiding direction to ensure sufficient yarn delivery. The air flow vectors can be influenced by the geometry of the air twist chamber, the yarn channel and the injection opening.
In order to achieve both a sufficient number and strength of knots and sufficient yarn tension and guidance, high air pressures and quantities were necessary with conventional interlacing nozzles. By steering the air flow through the geometry in accordance with the invention, the proportions of the air flow vectors in the yarn guiding direction and in the transverse direction are optimized in such a way that the air quantity and air pressure can be reduced without compromising quality and thus energy can be saved.
It has been shown that a ratio of a chamber length of the air twist chamber to a chamber extension transverse to the chamber length of at least 1.8 directs the air flow within the air twist chamber over a longer area transverse to the yarn guiding direction, so that lower air pressures and air quantities are necessary to ensure sufficient interlacing of the yarn. Such an interlacing nozzle guides the air flow introduced through the injection opening in such a way that the amount of fluid introduced can be reduced by up to 20% and yet the yarn still has the required knot count and knot strength after treatment.
In particular, the chamber length can be 180%, 200%, 218%, 228%, 330% of the chamber extension, preferably at a chamber extension of 1.5 mm, 2 mm, 3 mm or 3.5 mm. Specific values may be, for example, 1.75 mm, 2.67 mm, 2.94 mm or 3.08 mm. Preferably, the chamber length is at least 35% of the total nozzle length. The total nozzle length consists of the yarn channel length and the chamber length.
The chamber extension is understood here as the maximum extension of the air twist chamber in a transverse direction transverse to the yarn guiding direction and to an air twist chamber depth.
The air twist chamber may comprise two chamber regions in direct succession, the chamber length being composed of the lengths of the chamber regions.
The air twist chamber may comprise only one chamber region, the chamber walls of which are rounded. The radius of the rounding of the chamber walls may increase in yarn guiding direction to the center of the air twist chamber and then decrease again.
However, the air twist chamber may also comprise two air twist chamber regions, the walls of which are rounded in yarn guiding direction and the rounding of the first region in yarn guiding direction has a larger radius than that of the second region. In this case, the walls of the regions preferably merge into one another without a kink.
The air twist chamber regions may have a cross-section in a plane along the channel axis of the yarn channel and in the transverse direction which is substantially teardrop-shaped, such that the chamber regions have round sections and straight sections. The straight sections are arranged to converge in the yarn guiding direction and the opposite direction, respectively.
Preferably, the injection opening is arranged in the interlacing nozzle such that the air flow enters the air twist chamber at an angle greater than or less than 90° to the channel axis. Preferably, the injection opening is arranged so that the air flow enters the air twist chamber in a region of smaller extent than the chamber extent.
Preferably, the chamber extent is 15-45% of the channel width, preferably 15% and 35%, and preferably the chamber extent is at most 5 mm, preferably at most 3 mm wider than the channel width. When the chamber length is 330% of the chamber extent to form many nodes, the chamber extent is less. Typically, it is adjacent to 15% relative to the channel width. To create fewer but more stable nodes, a larger chamber extent is selected, e.g., 35% relative to the channel width.
This improves the air flow from the chamber into the yarn channel. The chamber expansion can preferably be between 1.75 mm and 17 mm.
Preferably, the chamber length is at most 350% of the channel width and is in particular at most 30 mm, preferably at most 20 mm, greater than the channel width.
Preferably, the air twist chamber has chamber walls which have at least one wall segment rounded in yarn guiding direction, in particular with a radius between 0.3 mm and 6 mm, preferably between 0.5 mm and 2 mm.
Preferably, the chamber is convexly rounded. Preferably, the chamber walls additionally comprise straight wall segments.
This allows the air to be easily guided in a specific direction.
Preferably, the chamber wall widens as viewed in yarn guiding direction starting from a channel wall. In particular, the chamber wall may widen at an angle of no more than 5° with respect to the yarn guiding direction and the channel wall.
Preferably, a first chamber region is arranged first in yarn guiding direction and a second chamber region immediately follows the first chamber region in yarn guiding direction. At the transition from the first chamber region to the second chamber region, the chamber has a constriction so that the chamber expansion in the first and second chamber regions is greater than the chamber expansion at the transition.
This allows the air flow to be separated. Due to the certain separation of the air mass, the amount of air per chamber region can be controlled in addition to the injection angle.
The air twist chamber may also include more than two chamber regions, each separated by constrictions. The air twist chamber may include other structures to direct the air flow, such as surface structures, ribs, edges, constrictions, or widenings. The air twist chamber may include coatings for swirling air.
The first chamber region may have a first chamber depth transverse to the chamber length and the chamber extent, and the second chamber region may have a second chamber depth transverse to the chamber length and the chamber extent, wherein the chamber depths may be different.
According to another aspect of the invention, the interlacing nozzle comprises a yarn channel having an air twist chamber. The air twist chamber has an injection opening for introducing air into the air twist chamber. A channel axis extends in a yarn guiding direction. According to the invention, the injection opening has a cross-section with at least one round section and at least one air guiding section, wherein the air guiding section is straight or has a radius of curvature that is at least 10 times larger than the radius of curvature of the round section.
The cross-sectional geometry of the injection opening has a direct influence on the quality of the turbulence and on the vectors of the flow direction.
Preferably, the air duct section(s) is not parallel to the channel axis. In an interlacing nozzle, the air flows in the transverse direction are decisive for the interlacing of the yarn. If the air is directed more in the transverse direction, the yarn will be more interlaced and more and stronger knots will be formed.
Preferably, the injection opening comprises, in cross-section, exactly four straight air conduit sections arranged in a substantially diamond shape and preferably interconnected by round corners forming the round sections. Preferably, a first line of symmetry of the diamond shape is arranged parallel to and preferably coinciding with the channel axis, so that a first corner of the diamond shape points in the yarn guiding direction and a second corner points in the opposite direction to the yarn guiding direction, and a third and a fourth corner point away in a common plane perpendicular to the first line of symmetry.
Thus, the air flow is easily directed already at the blowing-in stage The cross-sectional shape may alternatively be triangular or polygonal, with the corners being rounded in each case. Preferably, the shape comprises an even number of rounded corners, the cross-sectional shape being arranged in the air twist chamber such that the corners lead in both the yarn guiding direction and the opposite direction thereto.
The cross-sectional shape may also be trapezoidal or kite-shaped.
It has been shown that the number of knots and the stability of the knots can be influenced by the choice of the cross-sectional shape. A diamond shape injection opening results in fewer but more stable knots. A kite-shaped injection opening leads to more but less stable knots.
Preferably, the corners of the diamond shape are rounded. Preferably, the injection opening comprises a cross-section with an opening length in the yarn guiding direction and an opening width transverse to the opening length. The opening length and the opening width are different, and in particular a ratio between the opening length and the opening width is between 1.0 and 1.5. A smaller ratio, typically 1.0, is used to generate many nodes.
Thus, the rhombus comprises angles between the sides which are greater than or less than 90°. Preferably, the curves of the obtuse corners comprise a different radius than the curves of the acute angle corners.
Alternatively, the injection opening can be at least approximately oval in cross-section.
The specific selection of opening width and length allows the air volume to be steered in a particular direction: if the opening length is greater than the opening width, the angle at which the air flows into the chamber at the greatest velocity changes. The air flow can thus be directed.
Preferably, the opening length is smaller than the opening width, and preferably the first and second corners of the diamond shape are rounded with a larger radius than the third and fourth corners.
Alternatively, the opening width may be less than the opening length, with preferably the third and fourth corners of the diamond shape being rounded to a greater radius than the first and second corners.
This specific choice of opening allows precise alignment of air flow and air volume, and thus air velocity, depending on the yarns to be treated.
Another aspect of the invention relates to an interlacing nozzle having a yarn channel with an air twist chamber, which includes an injection opening for introducing air into the air twist chamber. In particular, the interlacing nozzle is an interlacing nozzle as previously described. A channel axis extends in a yarn guiding direction. The yarn channel has a channel width transverse to the channel axis. The air twist chamber has a chamber length in the yarn guiding direction and a chamber extension transverse to this length. The air twist chamber and/or the injection opening are so formed and arranged in the yarn channel that air introduced through the injection opening is guided in a vector which has more transverse components transverse to the channel axis inside the air twist chamber than axial components along the channel axis and more axial components than transverse components outside the air twist chamber.
In an interlacing nozzle, the air flow leading in the transverse direction to the channel axis results in greater interlacing of the yarn and is thus decisive for knot formation in the yarn.
The air flow in axial direction conveys the yarn in yarn guiding direction and thus leads to stronger yarn tension. As the air flow in the air twist chamber is more transverse than axial, more knots are created in the yarn. If the air is also guided more in the axial direction outside the air twist chamber, sufficient yarn tension is maintained to ensure a stable process. If the yarn tension is too low, the yarn flutters so much in front of the nozzle that it can break. Here, transverse components always include both radial and tangential components, since the radial components are decisive for the number of knots and the tangential components for the yarn tension.
The air twist chamber can be designed in such a way that the air is swirled over a range of at least 40% of the total nozzle length. The total jet length includes the length of the yarn channel and the chamber length of the air twist chamber.
Preferably, the transverse components include more radial components than tangential components.
The air is thus twisted more, which also twists the yarn more, creating stronger and more knots.
Alternatively, the transverse components have more tangential components than radial components.
This causes the yarn to be guided out of the die more, creating more yarn tension.
Further, the tasks are solved by a method for interlacing yarn. The yarn is guided along a yarn channel axis of a yarn channel of an interlacing nozzle. Air is introduced into an air twist chamber and guided in a vector within the air twist chamber. The vector inside the air twist chamber comprises more transverse components transverse to the channel axis than axial components along the channel axis, and outside the air twist chamber more axial components than transverse components.
This provides a simple way to ensure that the yarn achieves a high number of strong knots at low air volumes or pressures.
The patent or application file contains at least one drawing executed in color. Copies of this patent or patent application publication with color drawings will be provided by the Office upon request and payment of the necessary fee.
The invention is described in more detail in the figures. The figures show:
Along the yarn guiding direction F, the first channel section 1a is arranged first, followed by the first chamber region 2a, the second chamber region 2b and then the second channel section 1b.
An inlet section 3a is arranged at the inlet of the first channel section 1a and an outlet section 3b is arranged at the outlet of the second channel section 1b. The channel section 1a is shorter than the channel section 1b. Both channel sections have an extension 21 in the direction of the drawing plane of 1.7 mm. The nozzle plate 10 has a substantially mirror symmetrical configuration with respect to a plane through the center axes Ma and Mb and perpendicular to a plate surface.
The nozzle plate 10 includes a base surface 13, the base surface 13 having an outline comprising substantially two straight sides 15a and 15b arranged opposite each other and two rounded sides 16a and 16b also arranged opposite each other. The straight sides each have a substantially trapezoidal indentation 14a and 14b, the axes of symmetry of which lie on the central axes Ma and Mb. On each of the rounded sides, a protrusion 12a and 12b is arranged for mounting the nozzle on the holder. The protrusions 12a and 12b have substantially the same radius as the rounded sides 16a and 16b. However, the protrusions 12a and 12b are shorter than these sides.
The nozzle plate 10 further includes two circular openings 11a and 11b extending through the nozzle plate 10.
The air twist chamber 2 has a chamber length 29 of 4.69 mm in the yarn guiding direction F and a chamber extension 28 of 2.32 mm. The chamber extension 28 is to be understood as the largest extension of the air twist chamber 2 transverse to the chamber length 29 in the plate plane. This chamber expansion 28 and this chamber length 29 result in a length to expansion ratio of 2.02.
The nozzle plate 10 is connected to a cover plate so that the channel sections 1a and 1b and the air twist chamber 2 are closed. One or more yarns are introduced into and passed through the air twist chamber 2 while compressed air is applied to the yarn or yarns through the injection opening 4. As a result, knots are created in the yarn or yarns
Since the air twist chamber 2 is longer relative to the expansion, on the one hand the air is guided more in a transverse direction than in shorter chambers, and in addition the air is guided over a longer area in this transverse direction.
Air flow vector components transverse to the yarn guiding direction are responsible for the interlacing and thus for the knot number and strength. If the yarn is now interlaced more and over a longer area, more and tighter knots are formed.
This constriction 5 causes the air flow to be separated, creating two areas in which the air and thus the yarn are swirled differently.
The first chamber region 2a has a first region length 24 parallel to the central axes Ma and Mb, which is equal to or greater than the second region length 25 of the second chamber region 2b parallel to the central axes Ma and Mb. The chamber length 29 of the air twist chamber 2 consists of the first region length 24 and the second region length 25 and is 5.1 mm.
The chamber walls of the chamber regions 2a and 2b each lead away from the walls of the yarn channel at an angle. The chamber walls of the first chamber region 2a have an angle P of about 18° to 20° (specifically 19°) with respect to the walls of the yarn channel, and the chamber walls of the second chamber region 2b have an angle S of also 18° to 20°. A smaller angle (see also
However, other dimensions and geometries are also conceivable. The geometries described above can also be used for nozzle lengths of up to 45 mm with channel widths of up to 12 mm. The radii, e.g. in the yarn channel base, can then be adapted accordingly.
The injection opening 4 has a cross-sectional shape which is essentially a parallelogram with rounded corners 41-44. The rounded corners 41-44 are rounding sections. The sides of the parallelogram shape are air guiding sections 45, which serve to guide air in a particular direction. The first corner 41 points in yarn guiding direction F, and the second corner 42 points in the opposite direction to the yarn guiding device, so that the symmetry line 40 of the parallelogram shape is arranged along the center axes Ma and Mb. The first corner 41 and the second corner 42 are both rounded with a radius of 0.2 mm-2.5 mm. The third corner 43 and the fourth corner 44 are both in a plane perpendicular to the central axes Ma and Mb and are both rounded with a radius of 0.3 mm-3 mm. The angle between the straight sections is about 50° for the acute angle and about 130° for the obtuse angle. The injection opening has a width of typically 1 mm-10 mm, preferably about 1.32 mm, and a length of 0.8 mm-7 mm, preferably about 0.99 mm, and thus a width to length ratio of about 1.33:1.
If the injection opening has a parallelogram or diamond shape, as shown, the air is guided increasingly in a transverse direction to the yarn guiding direction, the transverse direction having components in both tangential and radial directions. The corners 41 and 42, which lie on the line of symmetry in the yarn guiding direction, are obtuse and the other corners 43 and 44 are acute. The angle of the corners has an influence on the orientation of the air flow, so that depending on whether the flow is to comprise more tangential or radial components, the angle can be adjusted.
The air twist chamber 102 of this embodiment has two chamber regions, wherein the chamber walls 127a of the first chamber region arranged in the yarn guiding direction F has a rounding in the yarn guiding direction with a radius which is larger than the radius of the rounding in the yarn guiding direction F of the wall portions 127b of the second chamber region. The radius of the rounding of the first wall portion 127a may vary. Typically, it is about 25 mm. The radius of the roundness of the second wall section 127b may also vary and be about 15 mm.
In the embodiment example shown here, the chamber length 129 of the air twist chamber 102 is 6.85 mm, and the chamber extension 128 is 3 mm. The extension 121 of the yarn channel 101 is 2.4 mm.
The injection opening 104 comprises substantially the same cross-sectional shape of a parallelogram as shown in
The injection opening 104 is arranged so that the air flow enters the air twist chamber 102 at an angle of less than 90°.
Such an injection opening, known per se, can also be arranged in an air twist chamber 2 of an interlacing nozzle according to the invention as shown in
Illustration 80 shows the air flow of a nozzle without an air twist chamber, as in
The illustration 82 shows the air flow of a nozzle according to the invention with an air twist chamber with a chamber length which is 1.6 times as large as the chamber extension.
The channel sections 1a, 1b have an extension 21 in the direction of the drawing plane of 1.7 mm.
The air twist chamber 2 has a chamber length 29 of 6.74 mm in the yarn guiding direction F and a chamber extension 28 of 2.0 mm. This chamber expansion 28 and this chamber length 29 result in a length to expansion ratio of approximately 3.37.
The chamber walls of chamber regions 2a and 2b each lead away from the walls of the yarn channel at an angle of about 6°. This serves to create many knots
The injection opening 4 has a kite-shaped cross-sectional form with rounded corners and with a rounded boundary in the chamber region 2a.
The injection opening 4 has a width B of about 1.13 mm and a length L of about 1.1 mm, and thus a width to length ratio of about 1:1.
The kite shape has an asymmetrical structure: Its length in chamber region 2a is 0.5 mm and in chamber region 2b 0.6 mm.
With nozzles according to the invention as shown in
| Number | Date | Country | Kind |
|---|---|---|---|
| 20190350.7 | Aug 2020 | EP | regional |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2021/072228 | 8/10/2021 | WO |
