EP4053320A1 - Nozzle strip for generating fluid jets for hydrodynamic consolidation of a sheet of material and system for consolidating such a sheet - Google Patents

Abstract

The invention relates to a nozzle strip for generating fluid jets for hydrodynamic bonding of a material web, with a large number of nozzle openings arranged in at least two rows spaced apart from one another for applying the fluid jets onto the material web, the nozzle openings being introduced as oblique bores in the nozzle strip, so that the fluid jets emerge from the nozzle strip along the longitudinal axes of the respective nozzle openings, with the nozzle strip being designed in such a way that the longitudinal axes of nozzle openings directly adjacent to one another in one and the same row and the longitudinal axes of nozzle openings directly opposite one another in directly adjacent rows are skewed to one another Plant for solidifying a web of material, comprising at least one nozzle bar and a nozzle strip which can be connected thereto in a fluid-conducting manner for generating fluid jets for the hydrodynamic solidification of the Material web, wherein the jet strip is designed according to the invention.

Description

The invention relates to a jet strip for generating fluid jets for hydrodynamic bonding of a web of material and a system for bonding such a web of material, comprising a jet bar and a jet strip according to the invention.

Devices of this type are used for hydroentanglement, for example, of material webs formed from fibers. By means of the invention, for example, webs of low to very high web weights made of natural fibers, synthetic fibers and spunbonded webs can be consolidated. In addition to this, structuring and/or perforations of the material web are possible with such a jet strip.

EP 1 309 743 B1 and EP 1 621 655 A1 disclose exemplary devices of this type. Thus, in each case a nozzle strip is provided which has a multiplicity of obliquely running nozzle openings. The nozzle openings are arranged, for example, in two rows running parallel to one another. Within the same row, the longitudinal axes of all nozzle openings also run parallel to one another, like the teeth of a comb.

A disadvantage of such a parallel alignment of the nozzle openings is that there are limits to the solidification of the material web.

It is therefore the object of the invention to provide a jet strip and a system for consolidating a web of material, by means of which the consolidation of such a web can be improved even further without increasing the structural complexity of the device.

The object on which the invention is based is achieved by a jet strip and a corresponding system for solidifying a web of material. Preferred embodiments of the invention are specified in the dependent claims, which can optionally be combined with one another.

According to the invention, the solidification of the web of material is significantly increased by skillful orientation of the oblique bores. For this purpose, the longitudinal axes become direct to each other adjacent nozzle openings in one and the same row and the longitudinal axes of nozzle openings directly opposite one another in directly adjacent rows are each oriented in such a way that the exiting fluid jets are skewed to one another. In other words, all nozzle openings in one and the same row and directly adjacent nozzle openings in directly adjacent rows never run parallel to one another. Due to the differently aligned fluid jets, i.e. the many changes in direction among each other, more turbulence of fibers occurs when the fluid jets hit the material web. As a result of the increased turbulence, the fibers intertwine even more, resulting in an increased strength of the material web compared to the prior art.

If, according to the invention, material web is mentioned, then what is meant is a fibrous web made of fibers. This can be in the form of woven fabrics, knitted fabric webs or nonwoven fabrics and preferably include the fibers mentioned at the outset.

The term "skew" means that the longitudinal axes of the nozzle openings neither intersect nor are parallel to one another. This means that part of the longitudinal axes that extends in the discharge direction of the fluid along the nozzle opening of the nozzle strip and beyond.

If we are talking about the longitudinal axes of the nozzle openings, then this means, for example, the symmetry axes of the same. Since the longitudinal axes essentially correspond to the discharge direction of the fluid jets, what was said about the longitudinal axes also applies in principle to the fluid jets themselves.

If, according to the invention, it is said that the nozzle openings are spaced apart from one another, then the distances are always meant in a plan view of the nozzle strip (XY plane), ie seen on the fluid inlet side. The distances from the respective point of intersection of the longitudinal axis of the corresponding nozzle opening with the XY plane are measured.

Oblique bores mean that the fluid jets or the longitudinal axes of the nozzle openings are inclined at an angle to a perpendicular to the XY plane of the nozzle strip or the material web. They can be aligned in such a way that these longitudinal axes lie in planes which are in turn perpendicular to the XY plane.

When, according to the invention, orientation is mentioned, this means the position of a longitudinal axis in space, in a Cartesian coordinate system. The location of a Longitudinal axis, which can be assumed to be a straight line, can be defined by a unit vector in space.

The nozzle strip is prismatic and has a length (X), width (Y) and height (Z) extension. The designations X, Y, Z correspond to the axis designations of the same name in a Cartesian coordinate system. The respective longitudinal axes of the corresponding nozzle openings are at an angle of inclination of 1° to 20°, preferably 1° to 10°, particularly preferably 1 ° up to 5° inclined. This angle has proven to be particularly advantageous in order to create a particularly favorable turbulence of the fibers of the web of material. The size of the angle of inclination depends, among other things, on the distance between the nozzle strip and the surface of the web or web of material. In the case of short distances, for example up to 10 mm, the angle of inclination can be selected to be larger. In the case of large distances, for example more than 25 mm, an angle of inclination in the range from 1° to 5° can be advantageous. However, the distances between the holes also play a role here. In principle, it can be provided that all oblique bores and thus all longitudinal axes of the nozzle openings in a row have the same angle of inclination. The at least two rows are preferably arranged at a distance from one another in the width extension (Y) of the nozzle strip. The rows can be arranged parallel but also at an angle to one another. The length X of the nozzle strip corresponds to the width of the material web, i.e. essentially the working width of the system, and conversely, the width Y of the nozzle strip corresponds to the length of the material web under the nozzle bar for a short period of time, in each case when the nozzle strip is installed.

Advantageously, the orientation of the longitudinal axes of directly consecutive nozzle openings in a respective row can be mirrored in relation to a respective plane of symmetry arranged between two adjacent nozzle openings in the respective row or can be point-mirrored to a point of symmetry arranged therein, so that from nozzle opening to nozzle opening within a row, inclined bores are alternately mirrored of the jet strip. For example, a symmetrical arrangement of individual nozzle openings directly adjacent to one another can be created. The advantages of the symmetry of the arrangement will be discussed later.

According to a further embodiment, the longitudinal axes of two directly adjacent nozzle openings of directly adjacent rows can lie in planes which run at an angle or orthogonally to one another and are preferably both perpendicular to the XY plane. This also promotes the symmetry of the arrangement of adjacent nozzle openings with one another.

The same applies to the arrangement of the nozzle openings: These can be arranged spaced apart from one another by a distance X1 within a row—seen in the longitudinal direction of the row and thus in the longitudinal extension (X) of the nozzle strip.

According to a first alternative A of the invention, directly adjacent rows of nozzle openings in the longitudinal direction of the row, i.e. seen in length (X), are offset from one another by half the distance X1, with the distance X1 corresponding to a multiple of the diameter of the nozzle openings, so that the nozzle openings directly adjacent rows are not directly opposite to each other as viewed in the direction of the width extension (Y) of the jet strip. This achieves a high degree of symmetry and a high packing density of the nozzle openings in the nozzle strip.

Such a symmetrical arrangement of the nozzle openings according to the invention, as has been described up to this point, describes the longitudinal axes of nozzle openings that are directly adjacent to one another—including those that extend across directly adjacent rows—as lines of a single-sheet hyperboloid. Individual or all of the longitudinal axes of the nozzle openings arranged in this way in nozzle openings directly adjacent to one another, also across directly adjacent rows, are thus arranged in such a way that they form parts of the lines of a hyperboloid. This arrangement causes these nozzle openings to produce jets of fluid that create a swirl about a virtual center of the nozzle openings. This twist leads to better turbulence of the fibers and thus to increased strengthening of the material web. The swirl is generated without the nozzles themselves having to rotate. This avoids a complex construction.

According to a second alternative B of the invention, when three rows of nozzle openings are provided, the nozzle openings of the first and third rows, which are arranged on both sides of the middle second row - seen in the longitudinal direction of the row and thus in the longitudinal extension (X) of the nozzle strip - towards the middle offset row. The two outer rows are slightly offset from the inclination of the fluid jet in the distance between the nozzle openings. Offset refers to the distance from the center of the nozzle opening on the top of the nozzle strip to the center of the nozzle opening on the bottom of the nozzle strip. The first row is offset from the middle row by a distance of 0.5*X1+X2 and the second row by a distance of 0.5*X1-X2, with the distance X2 being calculated using the following formula: 0 .5 times the height of the nozzle strip times the tangent of the angle of inclination of the respective longitudinal axis of the nozzle opening. As a result, there is a slight deviation from such a symmetry of directly adjacent nozzle openings compared to the arrangements from alternative A. The reason for this is that the image of the fluid jets when they impinge on the material web as a result of the orientation of the longitudinal axes according to the invention compared to the arrangement as it is in a plan view of the nozzle strip in the discharge direction of the fluid (perpendicular to the XY plane). This corrects this so that the points of impact are more evenly distributed on the material web, which in turn results in improved turbulence.

According to a third alternative C of the invention, when three rows of nozzle openings are provided, the nozzle openings within the middle row - as seen in the longitudinal direction of the row and thus in the longitudinal extension (X) of the nozzle strip - are each arranged at a distance X3 from one another, with the nozzle openings of remaining two rows within the row in question are spaced alternately from one another by a distance of 2*X3 and 4*X3, so that the nozzle openings of directly adjacent rows are not directly opposite one another as seen in the direction of the width extension (Y) of the nozzle strip, and that individual nozzle openings are more directly adjacent to one another Rows always have the same distance X3 seen in the longitudinal extension (X) of the jet strip to one another. This always results in equidistant distances from nozzle opening to nozzle opening, as a result of which the impingement of the fluid jets on the material web is standardized and the turbulence along the entire web width of the material web is thus improved.

According to a fourth alternative D of the invention, individual or all nozzle openings in the middle row are shifted alternately along the width extension (Y) of the nozzle strip towards one of the two rows. As a result, a better, namely square, distribution of the impact points over the full width of the web of material to be consolidated is again achieved.

The nozzles of the nozzle strip can preferably be arranged in such a way that in at least two rows of nozzles the nozzles form a square, rectangle or rhombus, with the longitudinal axes of the nozzles being aligned with points of a virtual circle on the plane of the material web which is within the square or Rectangle is arranged. The arrangement of the nozzles does not have to be on the corner points of the square or rectangle, but can be arranged on one of the outer edges. By aligning the nozzles on a virtual circle or a virtual ellipse in the plane of the material web, a twist is generated, which improves the turbulence of the fibers among themselves and thus the isotropy of the material web, at least on the surface. The swirl generated preferably alternates from nozzle arrangement to nozzle arrangement in a clockwise and anti-clockwise direction.

Finally, the present invention also relates to a system for solidifying a web of material, comprising at least one nozzle bar and one fluid-conducting therewith connectable nozzle strips for generating fluid jets for hydrodynamic solidification of the material web, the nozzle strip being designed according to the invention.

Further measures improving the invention are presented in more detail below together with the description of a preferred exemplary embodiment of the invention with reference to the figures.

Fig.1:

eine Ausführungsform der Anlage gemäß der Erfindung;

Fig. 2a bis 2d:

die Alternativen A bis D des erfindungsgemäßen Düsenstreifens in einem Schnitt A-A gemäß Fig. 1;

Fig. 3:

die erfindungsgemäße Orientierung der Längsachsen L der Düsenöffnungen als Linien eines einschaligen Hyperboloids;

Fig. 4:

eine Schnittdarstellung gemäß Schnittlinie A1-A1 in den Fig. 2a bis 2d;

Fig. 5:

eine Draufsicht auf einen Düsenstreifen einer weiteren Ausführungsform;

Fig. 6:

eine vergrößerte Draufsicht auf den Düsenstreifen der Figur 5;

Fig. 7:

eine Schnittdarstellung durch den Düsenstreifen der Figur 5 mit dem auftreffenden Fluidstrahl auf die Materialbahn.

Show it:

Fig.1:

an embodiment of the plant according to the invention;

Figures 2a to 2d:

the alternatives A to D of the jet strip according to the invention in a section AA according to 1 ;

Figure 3:

the orientation according to the invention of the longitudinal axes L of the nozzle openings as lines of a single-sheet hyperboloid;

Figure 4:

a sectional view along section line A1-A1 in the Figures 2a to 2d ;

Figure 5:

a plan view of a jet strip of a further embodiment;

Figure 6:

an enlarged plan view of the jet strip of FIG figure 5 ;

Figure 7:

a sectional view through the jet strip of figure 5 with the impinging fluid jet on the material web.

1 shows a highly schematic, partially sectioned side view of a system 1 according to the invention for solidifying a material web 2, comprising a nozzle bar 3 and a nozzle strip 4 according to the invention. A material web 2 is transported on a circulating belt 7 and solidified by means of fluid jets 6. In this exemplary embodiment, the nozzle bar 3 has a nozzle strip 4 with two rows of nozzle openings 5 . According to the invention, there can also be three rows of nozzle openings 5 . The nozzle bar 3 is fluidly connected to a reservoir of fluid, such as water, for example with the interposition of pumps, not shown. In the area of the water outlet from the nozzle bar 3, a nozzle strip 4 is arranged in an exchangeable manner. When the system 1 is operated as intended, the pressurized fluid thus reaches the nozzle strip 4 via the nozzle bar 3. From there it emerges from a large number of nozzle openings 5 arranged in the nozzle strip 4 and designed as oblique bores. At the exit of the nozzle openings 5 from the nozzle strip 4, the fluid forms a multiplicity of fluid jets 6. These act on the material web 2 passing underneath to solidify it hydrodynamically. A suction device 8 for removing the fluid penetrating the material web 2 is arranged below the belt 7 .

The representations of Figures 2a to 2d each show a sectional view of the nozzle strip according to section AA 1 the four different alternatives A to D of the invention mentioned at the outset. This sectional view of the prismatic jet strip 4 in the figures mentioned also corresponds to the XY plane, with X indicating the length of the jet strip 4 and Y indicating the width of the same, as soon as the jet strip 4 is shown in a Cartesian coordinate system, as shown here. The nozzle openings 5 are indicated as circles in the figures. In Figure 2a the nozzle strip has three parallel rows of nozzles 5, namely the first row R1, the second or middle row R2 and the third row R3. A large number of nozzles 5 are assigned to each row of nozzles, with only a maximum of 5 nozzles in a row being shown here and in the following figures. The nozzles are named according to the rows, ie for row R1 the nozzles 5.11, 5.12 and 5.13. As can be seen, the nozzle openings 5 are each divided into two ( Fig. 2d ) or three ( Figures 2a to 2c ) - here in mutually parallel rows - arranged. The arrows following the circles are intended to represent the longitudinal axes L of the respective nozzle openings 5: Since the nozzle openings 5 are designed as oblique bores, you have to imagine their course corresponding to the longitudinal axis L. The arrows can be understood here as vectors. These vectors correspond to projections of the unit vectors, which describe the respective longitudinal axis L as a straight line in space, onto the XY plane. For clarification is in 4 the course of the oblique bore is indicated in a section A1-A1, and the angle of inclination of the longitudinal axis relative to the perpendicular (lower part) is also indicated.

In the representations of Figures 2a to 2c one recognizes three rows R1, R2, R3 of nozzle openings 5. The nozzle openings 5.21-5.24 of the middle row R2 are in the Figures 2a and 2b always spaced apart by a distance X1. In Figure 2a the first and third rows R1, R3, which are arranged on both sides of the second and middle row R2, are shifted in the longitudinal extension X of the nozzle strip 4 by half the distance X1 against the middle row R2. Thus, in the direction of the width extension Y of the nozzle strip 4, the nozzle openings 5 are not directly opposite one another from row to row.

With view on Figures 2a to 2d it is noticeable that the orientations of the nozzle openings 5 in one and the same row alternate from nozzle opening 5 to nozzle opening 5. This can be seen, for example, in the first row R1 of nozzle openings 5 from the longitudinal axes L of two directly adjacent nozzle openings 5.11 and 5.12 or 5.12 and 5.13, which run in opposite directions to one another (see, for example, Figure 2a ). If one considers the nozzle openings 5 directly adjacent to one another in directly adjacent rows, it is noticeable that their orientations in space are also different. For example, the longitudinal axes L of the nozzle openings that are directly adjacent (also across the rows) are always skewed to one another. This is reflected in the orientations of the arrows, which can be considered vectors:
These are arranged "rotating" in a clockwise direction. According to the illustration in Figure 2a this is achieved by defining the jet strip according to the features of claim 6. The longitudinal axes L of the nozzle openings 5.11, 5.22, 5.31 and 5.21 are partially shown as lines of a single-sheet hyperboloid (see bold solid lines in 3 ) to understand. The latter can be achieved by rotating the longitudinal axis L of the nozzle opening 5 about a center 5.5—for example, which lies between the nozzle openings 5.11, 5.22, 5.31 and 5.21 and which can be an axis of symmetry. Thus, the remaining longitudinal axes L of the nozzle openings 5.22, 5.31 and 5.21 are the result of 90° rotations of the longitudinal axis L of the nozzle opening 5.11 around this center 5.5. Due to this special symmetrical arrangement, the fluid jets emerging from the nozzle openings are given a twist that runs to the right around the center 5.5 (see also the lower part of the longitudinal axes L of the figure 3 , although many longitudinal axes are shown here in an exaggerated manner). If you look in the Figure 2a Further to the right, it is noticeable that the adjacent group of nozzle openings 5.12, 5.23, 5.32 and 5.22 is a mirror image of the nozzle openings 5.11, 5.22, 5.31 and 5.21 just described. The twist runs to the left. This special arrangement and orientation of the longitudinal axes L of the nozzle openings 5, as also protected by claims 3 to 5, can achieve a particularly advantageous swirling of the fibers of the material web 2 by entraining them as a result of the fluid jets 6 set in a twist. As a result, the strength of the hydrodynamically consolidated web of material 2 is significantly increased.

In the representations of Figure 2b and 2c it is the alternatives B and C of the nozzle strip 4 described above. The first and second rows are offset according to the features of claims 7 and 8 with respect to the middle row in the direction of length X. This is done in order to achieve a more homogeneous impingement pattern ("image") of the fluid jets 6 as a result of the nozzle openings 5 now being arranged equidistantly from one another on the material web 2 and thus a more uniform and improved turbulence over the entire length of the nozzle strip 4 and thus over the width of the material web to score 2. In Figure 2b are provided with three rows R1, R2, R3 of nozzle openings 5, the nozzle openings of the first and third row R1, R3, which are arranged on both sides of the middle second row R2 - in the longitudinal direction of the rows R1, R3 and thus in the length (X) of the Nozzle strip seen - offset from the middle row R2.

The two outer rows R1, R3 are minimally offset from the inclination of the fluid jet 6 at a distance X1 of the nozzle openings 5. Offset refers to the distance from the center of the nozzle opening on the top of the nozzle strip to the center of the nozzle opening on the bottom of the nozzle strip. The first row R1 is offset by a distance of 0.5*X1+X2 and the third row R3 by a distance of 0.5*X1-X2 relative to the second and middle row R2, with the distance X2 increasing by using the following formula: 0.5 times the height of the jet strip 4 times the tangent of the angle of inclination of the respective longitudinal axis of the nozzle opening 5. This slightly deviates from such a symmetry of directly adjacent nozzle openings compared to the arrangements from alternative A. The reason for this is that the image of the fluid jets 6 when they hit the material web 2 as a result of the orientation of the longitudinal axes according to the invention compared to the arrangement as it is in a top view of the nozzle strip 4 in the discharge direction of the fluid (perpendicular to the XY plane), is advanced. This is corrected in this way, so that the impact points are distributed more evenly on the material web 2, which in turn results in improved turbulence.

In Figure 2c the third alternative C of the invention with the provision of three rows of nozzle openings 5 is described. The nozzle openings 5.21, 5.22, 5.23, 5.24 within the second and middle row R2—seen in the longitudinal direction of the row R2 and thus in the length (X) of the nozzle strip—each have a distance of 3×X3 from one another. The center 5.5 of a turbulence unit is now formed by nozzles 5.11, 5.22, 5.31, 5.21 arranged offset to one another, which are arranged in the longitudinal direction X of the nozzle strip 4 by the distance X3 in each case. The nozzle opening 5.21 is arranged at a distance X3 from the nozzle opening 5.11, this at a distance X3 from the nozzle opening 5.31 and this at a distance X3 from the nozzle opening 5.22.

The nozzle openings of the remaining two rows within the relevant row R1, R3 are alternately arranged at a distance of 1x X3 and 3x X3 from one another, so that the nozzle openings of directly adjacent rows R1, R2; R2, R3 viewed in the direction of the width extension (Y) of the nozzle strip are not directly opposite one another, and that individual nozzle openings in directly adjacent rows always have the same distance X3 from one another as viewed in the longitudinal extension (X) of the nozzle strip. This always results in equidistant distances from nozzle opening to nozzle opening, as a result of which the impingement of the fluid jets on the material web is standardized and the turbulence along the entire web width of the material web is thus improved.

Finally, the representation of Fig. 2d the initially described alternative D of the jet strip 4 according to the invention Figure 2c . Thus, the nozzle openings 5 of the middle row R2 have been successively and alternately shifted to the first row R1 or third row R3, which lie on either side of the middle row R2. There are therefore only two rows R1, R3 of nozzle openings 5. This measure also serves to improve the symmetry of the impingement of the fluid jets on the material web 2.

figure 3 shows the effect of the impinging through the arrangement of the nozzle openings 5 fluid jets 6 on a material web 2. The inventive arrangement of Nozzle openings 5, a twist is generated around a virtual center 5.5 of the nozzle openings. This twist leads to better turbulence of the fibers and thus to increased strengthening of the material web 2. The twist is generated without the nozzles themselves having to rotate. This avoids a complex construction. Such a symmetrical arrangement of the nozzle openings according to the invention, as has been described up to this point, describes the longitudinal axes L of nozzle openings that are directly adjacent to one another—including those that extend across directly adjacent rows—as lines of a single-sheet hyperboloid. Individual or all of the longitudinal axes of the nozzle openings arranged in this way in nozzle openings directly adjacent to one another, also across directly adjacent rows, are thus arranged in such a way that they form parts of the lines of a hyperboloid. This arrangement generates a swirl of fluid jets 6 without a component having to rotate.

figure 4 shows a section through a nozzle opening 5 along the section plane A1-A1 from FIGS Figures 2a - 2d . The nozzle strip 4 is prismatic and has a length (X), width (Y) and height (Z) extent. The designations X, Y, Z correspond to the axis designations of the same name in a Cartesian coordinate system. The respective longitudinal axes L of the corresponding nozzle openings are at an angle of inclination α of 1° to 20°, preferably 1° to 10°, particularly preferably 1 ° up to 5° inclined. This angle has proven to be particularly advantageous in order to create a particularly favorable turbulence of the fibers of the web of material 2 . In principle, it can be provided that all oblique bores and thus all longitudinal axes of the nozzle openings 5 have the same angle of inclination. The at least two rows R1, R2 are preferably arranged at a distance from one another in the width extension (Y) of the nozzle strip. The rows can be arranged parallel but also at an angle to one another. The length X of the nozzle strip essentially corresponds to the width of the material web 2.

In another embodiment of the Figures 5 to 7 an arrangement of two rows R1, R2 of nozzles of a nozzle strip 4 is shown, the nozzle openings 5 of which are directed towards a virtual circle or ellipse. The virtual circle or ellipse lies in the plane of the material web, i.e. by the distance X4 below the nozzle openings 5. Four fluid jets 6 each from four nozzle openings 5 are aligned in such a way that the fluid jets 6 hit points of a virtual circle or an ellipse of the material web 2 hit. The nozzles of the first row 5.11, 5.12 and the second row 5.21, 5.22 are spaced apart from X1 in the X direction. The distance between the rows of nozzles is X3. The distances X1 and X3 can be the same size with the same orientation of the nozzle openings 5, so that the exiting fluid jets 6 impinge on the material web 2 at points of a virtual circle. or In other words, the fluid jets 6 impinge tangentially on a virtual path of a circle or an ellipse that lies in the plane of the material web 2 . If the distances X1 and X3 are different, the exiting fluid jets 6 can impinge on points of a virtual ellipse on the material web with the same orientation of the nozzle openings 5 . The fluid jets 6 generate a twist in the plane of the material web 2 in a clockwise or counter-clockwise direction, with which the fibers are intertwined with one another in addition to the known turbulence. The effect is contrary to the previous orientation of the fibers, which are arranged one-sidedly in the production direction (MD direction) in accordance with the production direction of the material web 2 in the MD/CD ratio. The arrangement or impingement of the fluid jets 6 on the virtual circular path makes the alignment of the fibers in the MD/CD ratio in the material web 2 more uniform, and at the same time the strength of the material web 2 is increased by the twisted turbulence of the fibers among one another. In the embodiment of figure 5 the groups of nozzles alternately produce a clockwise or anti-clockwise twist on the material web 2. The section plane AA is shown in figure 7 shown. The twist direction changes in the direction of the working width (X-direction). The size of the virtual circle is determined by the distance X4 between the nozzle bar 4 and the surface of the material web 2, by the angle of inclination α of the nozzle opening in the nozzle bar 4 and by one of the angles β or γ, and by the angle δ. In the Figures 5 and 6 a symmetrical arrangement of the virtual circle between the nozzles 5.11, 5.12, 5.21, 5.22 is shown. However, the virtual circle can also be arranged asymmetrically within the rectangle X1, X3 by varying the angles β or γ and δ. The angle δ represents the alignment of the fluid jet 6 or the inclination of the nozzle opening 5 to the center of the virtual circle or ellipse. The angle β represents the alignment of the fluid jet 6 or the inclination of the nozzle opening 5 to the longitudinal axis of the nozzle bar 3, i.e. to the X-direction. The angle γ represents the orientation of the fluid jet 6 or the inclination of the nozzle opening 5 to the production direction, ie to the Z-direction. The angles β and γ together result in a right angle.

The alignment of the nozzle openings 5 after the Figures 2a to 3 always takes place in the direction of the longitudinal axis of the nozzle bar 3 (X direction) and in the production direction of the material web 2 (Y direction). The fluid jets created in this way are parts of the lines of a hyperboloid.

The alignment of the nozzle openings 5 after the Figures 5 to 7 occurs within a rectangle or square of nozzles 5.11, 5.12, 5.21, 5.22 and are all directed inwards towards a virtual circle, the jets hitting the virtual circle tangentially. Seen in the Z-direction, four nozzles 5.11, 5.12, 5.21, 5.22 are inclined in this way towards the common center of a virtual circle. The circle lies in the plane of the material web 2 to be processed at a distance X4 mm below the nozzle strip 4. In this exemplary embodiment, four fluid jets produce a twist in the plane of the material web 2 clockwise, which swirls the fibers together. The four other nozzles 5.13, 5.14, 5.23, 5.24 arranged next to it produce a suitable inclination as in FIG figure 5 a counterclockwise twist. The 4 neighboring beams in the middle of Figure 5 are inclined in such a way that an anti-clockwise twist occurs. The other four nozzles 5.15, 5.16, 5.25, 5.26 in figure 5 in turn generate a twist in the clockwise direction. The direction of twist is thus seen alternately in the direction of the working width or longitudinal axis of the nozzle bar 3 (X direction).

Transferred to the embodiment of Figures 2a to 2c the nozzles 5.11, 5.22, 5.31 and 5.21 from three rows of nozzles R1, R2, R3 can lie on the edges or lines of a square or rectangle and their longitudinal axes L can also be aligned on a virtual circle with the center 5.5. The invention does not require that the nozzles have to be arranged on the corner points of a square. They can also be arranged on the corner points of an arbitrarily arranged rhombus or on the outer edges of a square, rectangle or rhombus, the points impinging on the fluid jets lying on the virtual circle or ellipse in the plane of the material web within this geometric shape, around the desired to create a swirl effect.

Preferably, four nozzles from two nozzle rows R1, R2 form a square, so that X1=X3. The angle α is the same for all nozzle openings.

The distance X3 can also be smaller or larger than the distance X1. However, the angles β or γ and δ can be adjusted in such a way that the points of impingement of the four fluid jets 6 lie on a virtual circle or an ellipse.

For example, the nozzle opening 5 of all nozzles can be 0.12 mm and the distances X1, X2, X3 can each be 1.5 mm. The diameter of the virtual circle is according to the embodiments Figures 5 to 7 smaller than dimension X1, at least 0.5 mm. If the diameter of the virtual circle becomes smaller, there is no longer any appreciable swirl with these dimensions, since the fluid jets almost all hit one point.

The angle of inclination α is in the range from 1° to 20°, preferably from 1° to 10°, particularly preferably from 1° to 5°. This angle has proven to be particularly advantageous in order to create a particularly favorable turbulence of the fibers of the web of material. The size of the angle of inclination depends, among other things, on the distance between the nozzle strip and the surface of the web or web of material. In the case of short distances, for example X4 to 10 mm, the angle of inclination can be selected to be larger. In the case of large distances, for example X4>25 mm, an angle of inclination in the range from 1° to 5° can be advantageous. Of course, the distances between the nozzle openings also play a role here.

According to the invention, additional turbulence and thus knotting of the fibers or filaments is achieved, so that the integration of fibers or filaments on the nonwoven surface is improved. The web of material becomes more isotropic, at least on the surface, and thus the strength or the MD/CD ratio is evened out.

Reference sign

1

attachment

2

web of material

3

nozzle bar

4

jet strip

5

nozzle opening

5.11-5.15

Nozzles of the first row of nozzles

5.21-5.24

Nozzles of the second row of nozzles

5.31-5.35

Nozzles of the third row of nozzles

5.5

center

6

fluid jet

7

tape

8th

suction device

L

Longitudinal axis of the nozzle

X,Y,Z

Length, width, height extension of the jet strip

X1

Spacing of nozzles in a row

X2

Offset from nozzle inlet to nozzle outlet

X3

Spacing of nozzles of different rows

X4

Distance of the material web from the jet strip

X5

Spacing of nozzles in a row

A-A

cutting plane

R1-R3

row of nozzles

a

tilt angle

β

tilt angle

g

tilt angle

δ

tilt angle

Claims (14)

Nozzle strips (4) for generating fluid jets (6) for the hydrodynamic consolidation of a material web (2), with a large number of nozzle openings (5) arranged spaced apart from one another in at least two rows (R1, R2, R3) for discharging the fluid jets (6). the material web (2), wherein the nozzle openings (5) are made as oblique bores in the nozzle strip (4), so that the fluid jets (6) emerge from the nozzle strip (4) along the longitudinal axes (L) of the respective nozzle openings (5), wherein the nozzle strip (4) is designed in such a way that the longitudinal axes (L) of nozzle openings (5) directly adjacent to one another in one and the same row and the longitudinal axes (L) of nozzle openings (5) directly opposite one another in directly adjacent rows each run skewed to one another. Nozzle strip (4) according to claim 1, characterized in that the nozzle strip (4) has a length (X), width (Y) and height extension (Z) and the respective longitudinal axes (L) of the corresponding nozzle openings (5) opposite a perpendicular to an XY plane, which is spanned by the width and length of the nozzle strip (4), by an angle of inclination (α) of 1° to 20°, preferably 1 to 10°, particularly preferably 1 to 5° are inclined, the at least two rows preferably being spaced apart from one another in the width extension (Y) of the nozzle strip (4). Nozzle strip (4) according to Claim 1 or 2, characterized in that the longitudinal axes (L) of nozzle openings (5) directly following one another in a respective row are mirrored in their orientation with respect to a respective plane of symmetry arranged between two adjacent nozzle openings (5) in the respective row or are point-mirrored at a point of symmetry arranged therein, so that from nozzle opening (5) to nozzle opening (5) within a row, oblique bores of the nozzle strip (4) are alternately mirrored and oriented. Nozzle strip (4) according to Claim 2 or 3, characterized in that the longitudinal axes (L) of two directly adjacent nozzle openings (5) of directly adjacent rows lie in planes which run at an angle or orthogonally to one another and are preferably both perpendicular to the XY plane . Nozzle strip (4) according to any one of claims 1 to 4, characterized in that the nozzle openings (5) within a row - seen in the longitudinal direction of the row and thus in the longitudinal extent (X) of the nozzle strip (4) - are each arranged spaced apart from one another by a distance (X1). Nozzle strip (4) according to one of Claims 2 to 5, characterized in that directly adjacent rows of nozzle openings (5) are arranged offset from one another by half the distance (X1) in the longitudinal direction of the row, i.e. viewed in length (X), wherein the distance (X1) corresponds to a multiple of the diameter of the nozzle openings (5), so that the nozzle openings (5) of directly adjacent rows, viewed in the direction of the width extension (Y) of the nozzle strip (4), are not directly opposite one another. Nozzle strip (4) according to Claim 6, characterized in that when three rows of nozzle openings (5) are provided, the nozzle openings (5) of the first and third rows (R1, R3), which are arranged on either side of the middle row (R2) - in Seen in the longitudinal direction of the row and thus in the longitudinal extent (X) of the nozzle strip (4) - are offset from the middle row (R2), the first row (R1) by a distance of 0.5*X1+X2 and the third row ( R3) is offset from the second middle row (R2) by a distance of 0.5*X1-X2, with the distance X2 resulting from the following formula: 0.5 times the height of the jet strip (4) times the tangent of the Angle of inclination of the respective longitudinal axis (L) of the nozzle opening (5). Nozzle strip (4) according to one of Claims 2 to 4, characterized in that when three rows of nozzle openings (5) are provided, the nozzle openings (5) within the middle row (R2) - in the longitudinal direction of the row and thus in the length (X) of the nozzle strip (4) - are each arranged spaced apart from one another by a distance n*X3, the nozzle openings (5) of the remaining two rows (R1, R3) within the row in question alternating with one another by the distance (n-1)*X3 and (n+1)*X3 are spaced apart, so that the nozzle openings (5) of directly adjacent rows are not directly opposite one another when viewed in the direction of the width extension (Y) of the nozzle strip (4), and that individual nozzle openings (5) of directly adjacent rows are always have the same distance X3 from one another as seen in the longitudinal extent (X) of the nozzle strip (4), n preferably being three. Nozzle strip (4) according to Claim 8, characterized in that individual or all nozzle openings (5) in the middle row are shifted alternately along the width extension (Y) of the nozzle strip (4) towards one of the two rows. Nozzle strip (4) according to Claim 1 or 2, characterized in that in at least two rows (R1, R2, R3) of nozzles, the nozzles form a square or rectangle, the longitudinal axes (L) of the nozzles pointing to points of a virtual circle on the Level of the material web (2) are aligned, which is arranged within the square or rectangle. Nozzle strip (4) according to Claim 10, characterized in that at least four nozzles (5.11, 5.12, 5.21, 5.22) from two rows (R1, R2) are aligned tangentially to a virtual circle which is within the arrangement of the at least four Nozzles (5.11, 5.12, 5.21, 5.22) lie in the plane of the material web (2). Nozzle strip (4) according to one of Claims 10 to 11, characterized in that each nozzle is arranged at an angle (δ) which is between a line connecting the nozzle to the center (5.5) of the virtual circle and a tangent from the nozzle to the virtual circle in the plane of the material web (2) results. Nozzle strip (4) according to one of Claims 10 to 11, characterized in that the inclination of each nozzle is arranged at an angle (β) and (γ), the angle (β) resulting from the inclination of the nozzle opening (5) to the longitudinal axis of the Nozzle bar (3), i.e. to the X-direction, and the angle (γ) from the inclination of the nozzle opening (5) to the production direction, i.e. to the Z-direction. Plant (1) for solidifying a material web (2), comprising at least one nozzle bar (3) and a nozzle strip (4) which can be connected to it in a fluid-conducting manner for generating fluid jets (6) for hydrodynamic solidification of the material web (2), the nozzle strip (4) according to one of the preceding claims.

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