Nozzle and method for manufacturing knotted yarn

Abstract

Nozzle (1) for manufacturing knotted yarn (11), having a yarn duct (2) in which knots are producible with the aid of air entanglement. The nozzle includes at least one air bore (3) having a longitudinal axis (A), which merges with the yarn duct (2) in a merging opening (4). Air is introducible into the yarn duct (2) through the air bore. The longitudinal axis (A) of the air bore (3) is disposed at an angle of less than 90, preferably 65-85, particularly preferably 78 in relation to a conveying direction (B) of the knotted yarn (11). A baffle face (5) is configured on the opposite side of the merging opening (4) of the air bore (3) in the yarn duct (2), so as to be substantially perpendicular in relation to the longitudinal axis (A) of the air bore (3).

Claims

1. A nozzle for manufacturing knotted yarn comprising: a yarn duct, defining a conveying direction for yarn to be knotted, while the yarn is flowing through the nozzle, in which knots are producible with aid of air entanglement to produce the knotted yarn, and the yarn duct having an inlet opening and an outlet opening and at least one air bore having a longitudinal axis (A) located between the inlet opening and outlet opening, wherein said at least one air bore merges with the yarn duct in a merging opening and air is introducible into the yarn duct through the at least one air bore, the longitudinal axis (A) of the at least one air bore being disposed at an angle of less than 90 in relation to the yarn duct to assist with producing knots in the yarn to be knotted as the yarn to be knotted flows in the conveying direction (B) through the yarn duct, a baffle face being configured on an opposite side of the merging opening of the at least one air bore into the yarn duct, and said baffle face is substantially perpendicular in relation to the longitudinal axis (A) of the at least one air bore, and said baffle face being inclined with respect to the conveying direction (B) of the yarn to be knotted as the yarn to be knotted flows in the conveying direction (B) through the yarn duct.

2. The nozzle according to claim 1, wherein at least one of: a region of the inlet opening of the yarn duct is constricted in relation to a cross section of the yarn duct in a region of the merging opening of the at least one air bore, or the outlet opening of the yarn duct is widened in relation to a cross section of the yarn duct in the region of the merging opening of the at least one air bore, such that a larger net amount of air dissipates via the outlet opening than via the inlet opening.

3. The nozzle according to claim 1, wherein the yarn duct is configured so as to be in two parts that comprise a nozzle plate and a cover plate which are releasably connectable to one another.

4. The nozzle according to claim 1, wherein the baffle face has, in the conveying direction (B), a length of 2-4 times a diameter of at least one the air bore.

5. The nozzle according to claim 1, wherein a region of the inlet opening of the yarn duct is constricted in relation to a cross section of the yarn duct in a region of the merging opening of the at least one air bore, and the constriction in the region of the inlet opening is formed by a surface profile of a cover plate of the yarn duct.

6. The nozzle according claim 1, wherein a region of the inlet opening of the yarn duct is constricted in relation to a cross section of the yarn duct in a region of the merging opening of the at least one air bore and the constriction in the region of the inlet opening is formed by a surface profile of a cover plate and of a nozzle plate.

7. The nozzle according to one of claim 1, wherein the yarn duct displays an asymmetrical cross section.

8. The nozzle according to claim 1, wherein the angle is between 65 and 85.

9. The nozzle according to claim 1, wherein the outlet opening of the yarn duct is widened in relation to a cross section of the yarn duct in a region of the merging opening of the at least one air bore and the widening in the region of the outlet opening is formed by a surface profile of a cover plate of the yarn duct.

10. A method for manufacturing knotted yarn within a yarn duct defining a conveying direction for yarn to flow through the yarn duct and be knotted with aid of air entanglement, wherein air is introduced, through at least one air bore having a longitudinal axis (A), in a direction of the longitudinal axis (A) at an angle of less than 90 in relation to the yarn duct to assist with producing knots in the yarn as the yarn to be knotted flows in the conveying direction (B) through the yarn duct, said at least one air bore merges with the yarn duct at a merging opening located between an inlet opening and an outlet opening of the yarn duct, air is directed onto a baffle face, said baffle face is configured on an opposite side of the merging opening of the at least one air bore into the yarn duct and said baffle face is perpendicular in relation to the longitudinal axis (A) of the at least one air bore, and said baffle face is inclined with respect to the conveying direction (B) of the knotted yarn.

11. The method according to claim 10, wherein, on account of at least one of: a constriction in a region of the inlet opening of the yarn duct in relation to a cross section of the yarn duct in a region of the merging opening of the at least one air bore and on account, or a widening of the outlet opening of the yarn duct in relation to the cross section of the yarn duct in the region of the merging opening of the at least one air bore, a larger net amount of air dissipates via the outlet opening than via the inlet opening.

12. The method according to claim 10, wherein the angle is between 65 and 85.

13. The method according to claim 12, wherein the angle is 78.

14. The nozzle according to claim 10, wherein the outlet opening of the yarn duct is widened in relation to a cross section of the yarn duct in a region of the merging opening of the at least one air bore and the widening in the region of the outlet opening is formed by a surface profile of a cover plate and of a nozzle plate.

Description

(1) Further advantageous aspects of the invention are explained in the following by means of exemplary embodiments and the FIGS. In the drawings, in a schematic manner:

(2) FIG. 1 shows a first embodiment of a nozzle according to the invention in the cross section;

(3) FIG. 2 shows a further embodiment of a nozzle according to the invention in the cross section;

(4) FIG. 3 shows another illustration of the nozzle from FIG. 2;

(5) FIG. 4 shows an alternative embodiment of a nozzle according to the invention in the cross section;

(6) FIG. 5 shows a front view of the nozzle from FIG. 4;

(7) FIG. 6 shows an air stream onto a baffle face, in the cross section of the air bore;

(8) FIG. 7 shows a collection of various nozzles according to the invention in the cross section;

(9) FIGS. 8-11 show comparative measurements of nozzles according to the invention with nozzles from the prior art;

(10) FIG. 12 shows properties of knotted yarn from nozzles of FIG. 7 in comparison with a nozzle from the prior art.

(11) FIG. 1 shows a nozzle 1 according to the invention, having a yarn duct 2 and an air bore 3, in the cross section. The yarn duct 2 is formed by mutually interconnected plates 8, 9. The air bore 3 has a longitudinal axis A and merges with the yarn duct 2 in a merging opening 4. In the yarn duct 2, filaments 10 (not shown, see FIG. 3, for example) are conveyed in a conveying direction B. The merging opening 4, in the conveying direction B, is located in about the centre of the nozzle 1 and is disposed at an angle of about 85 in relation to the conveying direction B. Entanglement air 13 (not shown, see FIG. 5) is introduced into the yarn duct 2 in the direction of the longitudinal axis A through the air bore 3 via the merging opening 4. The entanglement air impacts a baffle face 5 in a perpendicular manner. On account of the impact of the entanglement air 13 on the baffle face 5, two partial flow turbulences 13, 13 are formed (not shown, see FIG. 5). The perpendicular impact of the entanglement air 13 makes for the configuration of two partial flow turbulences 13, 13, which are uniform and run in opposite directions. On account of this uniformity, part of the filaments are moved in the counter-clockwise direction and the remaining filaments are moved in the clockwise direction. On account of the movement of the filaments through the partial flow turbulences 13, 13, knots are formed in the region of the merging opening, ahead of and behind the incoming entanglement air 13. On account thereof, knotted yarn 11 consisting of entangled filaments (not shown, see FIG. 3, for example) is created from the filaments 10 (non-entangled yarn). What are referred to as continuous yarns are in particular suited as filaments.

(12) The yarn duct 2 is constricted in the region of the entry opening 6. An exit opening 7 of the yarn duct 2 is widened. The constriction and the widening are established by way of a surface profile of the cover plate 8.

(13) On account of the oblique position of the longitudinal axis A of the air bore 3 in relation to the running direction B of the filaments, a net dissipation via the exit opening 7 of the yarn duct 2 results. This net dissipation supports conveying of the filaments 10 or of the knotted yarn 11, respectively, through the yarn duct 2. The widening of the exit opening 7 moreover leads to the turbulences being guided away from the centre, i.e. away from the yarn. The intensity of the turbulences is also reduced hereby. On account thereof, the yarn 11 is not conveyed away from the centre of the yarn duct 2.

(14) FIG. 2 shows a nozzle 1 according to the invention, having the yarn duct 2 and the air bore 3 having the longitudinal axis A which is at 90 in relation to the conveying direction B. The yarn duct 2 is formed by the cover plate 8 and the nozzle plate 9. The yarn duct 2 is constricted in the region of an entry opening 6, and an exit opening 7 of the yarn duct 2 is widened. The constriction and the widening are formed by a surface profile of the cover plate 8. The constriction here is configured as an oblique step 12. The oblique step here leads away from the region of the entry opening 6, away from the merging opening of the air bore 3 in the conveying direction B, and thus away from the nozzle plate 9. The constriction at the entry opening 6 and the widening at the exit opening 7 lead to more air being dissipated via the exit opening 7 than via the entry opening 6. The widening is also configured as an oblique step which leads away from the nozzle plate 9 in the conveying direction B. Through the air bore 3, the entanglement air 13 is introduced into the yarn duct 2 and impacts the baffle face 5 in a perpendicular manner. The baffle face is 5 mm long, which is three times longer than a diameter of the air bore 3. Filaments 10 are introduced into the yarn duct 2 of the nozzle through the entry opening 6. On account of the entanglement air 13, the filaments 10 are guided largely along the surface of the cover plate 8. At the step 12, the filaments 10 are deflected around an edge 14 at the commencement of the step 12. On account of this deflection, the filaments 10 are flattened, such that the filaments 10 are transformed from a round shape to a tape shape. The tape shape offers the entanglement air 13 or the partial flow turbulences 1313 more contact surface. This leads to the filaments 10 being entangled in a consistently uniform manner and, on account thereof, consistently uniform knots are formed. A higher number of knots per metre, which are configured in a more uniform and stronger manner, results therefrom.

(15) FIG. 3 shows the nozzle 1 as in FIG. 2, having the constriction in the region of the entry opening 6 and the widened exit opening 7. In a schematic manner, small arrows show the distribution of the entanglement air 13 after entering into the yarn duct 2. On account of the constriction and the widening, a net dissipation of the air via the exit opening 7 takes place. Moreover, the constriction in the region of the entry opening 6 has the advantage that a stabilizing effect on the filaments 10 is created. On account thereof, the filaments 10 oscillate less, on account of which they are conveyed through the yarn duct 2 in a pacified, consistently uniform manner. On account of this low-oscillation type of conveying, fewer deviations arise during entanglement, such that the filaments 10 are knotted in a consistently uniform manner and the number of knots per metre is increased.

(16) Through the widening at the exit opening 7, the air turbulences are guided away at the exit opening 7 by the knotted yarn 11. On account thereof, the yarn 11 is not negatively influenced by the turbulences and is not carried out of the centre of the nozzle.

(17) FIG. 4 shows an alternative embodiment of the nozzle 1 having the widened exit opening 7. The widening is formed by both the cover plate 8 and also the nozzle plate 9. The widening in the two plates 8, 9 here is not configured as an oblique step but as surfaces of the plates 8, 9 which are curved in a convex manner in relation to the yarn duct. On account of the curved surface, in the longitudinal section, the nozzle exit looks similar to an end piece of a trumpet, as shown in FIG. 3. On account of the convex curvature, a Coand{hacek over (a)} effect arises, i.e. the air is guided away along the surface and does not interact with the filaments 10 in the centre of the yarn duct 2.

(18) FIG. 5 shows the nozzle 1 as in FIG. 4, in a front view onto the exit opening 7. The yarn duct 2 is formed by the cover plate 8 and the nozzle plate 9. The yarn duct 2 here displays a U-shaped cross section. The nozzle plate 9 here is configured so as to converge in a substantially pointed manner, and the cover plate 8 is configured having a substantially linear surface. On account thereof, an asymmetrical, V-shaped cross section is created. Asymmetrical cross sections, such as U-shaped, V-shaped, or T-shaped cross sections, are also applicable in the case of the further nozzles 1 according to the invention. Texturized yarn is best entangled using a U-shaped cross section as in FIG. 5.

(19) FIG. 6 shows a detail of the yarn duct 2 at the baffle face 5. The entanglement air 13 impacts the baffle face in a perpendicular manner. On account thereof, two uniform partial flow turbulences 13, 13 are created. Here, one partial flow turbulence 13 rotates in the clockwise direction, the second partial flow turbulence 13 rotates in the counter-clockwise direction. The partial flow turbulences convey the filaments 10, on account of which the filaments 10 are also twisted in the respective direction in relation to one another. On account thereof, the filaments 10 are knotted to form knotted yarn 11. On account of the uniform configuration of the partial flow turbulences 13, 13, the filaments 10 are also knotted in a consistently uniform manner.

(20) FIG. 7, in a schematic manner, shows four nozzles 1 according to the invention (V1/V2, V2/V3, V9/V9, V11/V10) in the cross section and in a detailed view, in the longitudinal section, at the entry opening 6. Four regions a), b), c), d) are identified in the nozzles 1. The region a) relates to a region of the air bore 3, b) relates to a region at the entry opening 6, c) relates to a region at the exit opening 7, and d) relates to a detailed view of the region of feature b) in the longitudinal section. The nozzles have in each case one yarn duct 2 having an asymmetrical cross section which is configured in a V-shape.

(21) V1/V2 displays the following features: a) The air bore 3 is perpendicular (90+/3) in relation to the baffle face 5, and perpendicular in relation to the conveying direction of the filaments 10. b) The increase in height at the entry opening 6 in relation to the total height of the yarn duct 2 at the merging opening 4 of the air bore 3 with the baffle face 5, as a basis, is 30%+/25%. The increase in height at the entry opening 6 in relation to the height of the yarn duct 2 of the cover plate 8 at the merging opening 4 of the air bore 3 with the baffle face 5, as a basis, is 60%+/30%. The constriction in height at the entry opening 6 in relation to the total height of the yarn duct 2 at the merging opening 4 of the air bore 3 is 40%+/30%. c) Air is rapidly dissipated on account of two angles in the exit opening 7 of the nozzle 1. The first angle is in the range of 5-10, and the second angle in the range of 20-35. d) On account of applying a centering element on the highest point of feature b), the yarn is retained in the centre of the yarn duct 2. The centering element is configured such that a clearance has been removed in the region of the constriction on the entry opening 6. The clearance is preferably configured so as to be U-shaped, V-shaped or trapezoidal, and on the cover plate. By way of the centering element, the yarn is retained so as to be spaced apart from the cover plate, in the centre of the yarn duct 2. On account of the spacing in relation to the cover plate, the filaments 10, however, are to a lesser extent or not deflected around an edge and thus brought into a tape shape, respectively.

(22) The nozzle V2/V3 has the same features a), b), and c) as the nozzle V1/V2. In contrast to the nozzle V2/V3, the yarn is pressed against the radius in the feature d), since no centering element which is configured as a clearance is present. On account thereof, the filaments are flattened (and become tape shaped).

(23) The nozzle V9/V9 has the same features a), b), d) as the nozzle V2/V3. In contrast to the nozzle V2/V3, the nozzle V9/V9 in the region c) has two tangential radii on the exit opening 7 of the yarn duct 2. On account of the radii, the air is rapidly dissipated. On account of the Coand{hacek over (a)} effect, the air is moreover guided along the surface of the cover plate 8, or nozzle plate 9, respectively. On account thereof, a pacified profile of the yarn 11 in the centre of the yarn duct 2 is ensured.

(24) The nozzle V11/V10 has the same features b), c), d) as the nozzle V2/V3. In contrast to the nozzle V2/V3 (and V1/V1, V9/V9), the nozzle V11/V10 has an air bore 3 which is inclined by approximately 78 in relation to the conveying direction of the filaments 10. The baffle face 5 is disposed so as to be perpendicular in relation to the air bore 3, such that the former points in an oblique manner into the yarn duct 2. On account of this arrangement, the yarn is conveyed by the air 13 of the inclined air bore 3, on the one hand, and on account of the baffle face 5 which is perpendicular to the air bore 3, an optimal entanglement of the filaments 10 is achieved, on the other hand.

(25) FIGS. 8-11 show test results obtained with nozzles 1 according to the invention, compared with Polyjet nozzles of the applicant, known from the prior art (HN 133, RPE). In contrast to the nozzles 1 according to the invention, Polyjet nozzles display at least one duct for introducing entanglement air and at least one duct for introducing conveying air. In the nozzle according to the invention, either both functions are assumed by the same duct, that is to say the air bore 3, and/or conveying is accomplished by a constriction in the region of the entry opening 6 and/or a widening of the exit opening 7. However, in both cases only one air bore is present.

(26) FIG. 8 shows a comparative measurement in which FP/s (fixed points per second/number of knots per second) are measured in relation to dpf (Denier per filament/weight per length). In the following case, filaments from polyester having the same density were used. In the case of same density of the filaments, dpf can be assumed to be equal to a diameter of the filaments. As shown in FIG. 8, more knots per time are achieved with nozzles according to the invention in comparison to the standard nozzle known from the prior art. Here, the nozzle V11/V10 having the obliquely positioned air bore achieved the best results.

(27) In the comparative test which is illustrated in FIGS. 9-11, the number of knots per metre (FP/m) were compared, depending on the pressure of the entanglement air in bar. Here, identical polyester filaments (PES filaments), i.e. having a consistent dpf, were used. In the case of a consistent air-bore diameter within a nozzle, the following applies: the higher the pressure, the more knots (knots/metre) are configured.

(28) In FIG. 9, Dtex68f34 which is composed of 34 filaments and weighs 68 grams per 10,000 m was used. In the test, the nozzles V9/V9 and V11/V10 according to the invention were compared to the standard nozzles HN 133, and RPE. Here, the number of knots per meter (FP/m) were compared, depending on the pressure of the entanglement air in bar. In the diagram, the lower border of the area of the respective nozzle shows the number of firm knots. The upper border shows the total number of knots, i.e. firm and soft knots combined.

(29) The firmness of the knots is measured by stressing the knotted yarn 11 with 0.3 cN/dtex, 0.5 cN/dtex, and 0.7 cN/dtex. After each stress cycle, the loss of knots in comparison with the unstressed knotted yarn 11 is represented in a percentage. Knots which open up at up to 0.3 cN/dtex are considered to be soft. Knots which remain in the yarn after a stress cycle of at least 0.5 cN/dtex are considered to be firm. Moreover, the knots are optically judged. The longer a knot, the more stable, i.e. the harder it is judged to be.

(30) In this manner, the nozzle V9/V9 at 3 bar achieves 18 firm knots and a total of 21 knots per metre, for example. The smaller the distance between the lower and the upper border of the area, the more uniform and firmer the knots. Nozzles according to the invention not only show more knots per metre, but in the case of many pressures also the more uniform and firmer knots. The nozzles according to the invention, in their configuration of uniform firm knots, depend to a lesser extent on a specific pressure than the nozzles of the prior art. On account thereof, the nozzles may be used for various entanglement processes. The pressure and thus the air consumption may be reduced without any significant drop in the number of knots.

(31) FIGS. 10 and 11 show the same measurements as in FIG. 9, wherein another thread (and other nozzles) were used, as compared with FIG. 9.

(32) In FIG. 10, the nozzles V1/V2 and V9/V9 were compared with the two standard nozzles from FIG. 9. A thread from 136 polyester filaments, having a weight of 136 g/10,000 m (FDY PES 136f68) was used. Using the nozzles according to the invention, in the case of most pressures more, and above all firm knots are more regularly achieved than with the nozzles from the prior art.

(33) In FIG. 11, the nozzle V11/V10 was compared with the nozzle HN 133 from the prior art. A thread from 144 polyester filaments, having a weight of 82 g/10,000 m (FDY PES 82f144) was used. Using the nozzle V11/V10 according to the invention, more knots are achieved than with the known nozzle.

(34) The tests illustrated in FIGS. 9-11 demonstrate that the nozzles according to the invention show better results than the nozzles from the prior art in the case of the most varied yarns.

(35) FIG. 12 shows knotted yarn which was manufactured using various nozzles 1 according to the invention (V1/V2, V2/V3, V9/V9, V11/V10) in comparison with knotted yarn manufactured using a standard nozzle (HN133A/CN14) from the prior art.

(36) Knotted yarn manufactured using the standard nozzle shows open spots and weak (short) knots. Moreover, the spacing between knots is non-uniform. In contrast, the nozzles 1 according to the invention show uniform long knots. Here, knotted yarn 11 of the nozzle V11/V10 displays a very high number of knots and the hardest knots. The properties of the yarns are listed in the following table.

(37) TABLE-US-00001 TABLE 1 No. of Knot Knot Nozzle type knots length Stability spacing Standard Average Average Average Non- HN133A/CN14 uniform V1/V2 High Average Average Uniform V2/V3 High Average Average Uniform V9/V9 Very high Short Soft Uniform V11/V10 Very high Long Hard Uniform