EP4053320B1 - Nozzle strip for generating fluid jets for hydrodynamic consolidation of a sheet of material and system for consolidating such a sheet - Google Patents

Description

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

Such devices are used for hydroentanglement, for example, of material webs formed from fibers. By means of the invention, for example, nonwovens from low to very high nonwoven weights made from natural fibers, synthetic fibers and spunbonds can be consolidated. In addition, structuring and/or perforations of the material web are possible with such a nozzle strip.

JP H06 184895 A , EP 1 309 743 B1 and EP 1 621 655 A1 disclose examples of such devices. A nozzle strip is provided in each case, which has a large number of oblique 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 each other, like the teeth of a comb. The 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 nozzle strip and a system for solidifying a material web, by means of which the solidification of such a web can be further improved without increasing the design effort of the device.

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

According to the invention, the solidification of the material web is significantly increased by cleverly orienting the oblique bores. To do this, the longitudinal axes become direct to each other adjacent nozzle openings of one and the same row and the longitudinal axes of directly opposite nozzle openings of directly adjacent rows are each oriented so that the emerging fluid jets are skewed to one another. In other words, all nozzle openings in one and the same row as well as 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 of 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 strongly, which results in an increased strength of the material web compared to the prior art.

When the term material web is mentioned according to the invention, what is meant is a fibrous web made from fibers. This can be in the form of woven fabrics, knitted fabric webs or nonwovens and preferably include the fibers mentioned at the beginning.

The term “skewed” means that the longitudinal axes of the nozzle openings neither intersect nor are parallel to one another. This refers to the part of the longitudinal axes that extends along the nozzle opening of the nozzle strip and beyond in the direction of delivery of the fluid.

If we are talking about the longitudinal axes of the nozzle openings, this means, for example, the axes of symmetry of the nozzle openings. Since the longitudinal axes essentially correspond to the direction of application of the fluid jets, what has been said about the longitudinal axes basically also applies 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 top view of the nozzle strip (XY plane), i.e. seen on the fluid inlet side. The distances from the respective 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 of inclination relative 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 that are in turn perpendicular to the XY plane.

When we talk about orientation according to the invention, this means the position of a longitudinal axis in space, in a Cartesian coordinate system. The location of one 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) extent. 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, relative to a perpendicular to an XY plane, which is spanned by the width and length extension of the nozzle strip ° inclined to 5°. This angle has proven to be particularly advantageous in order to produce particularly favorable swirling of the fibers of the material web. The size of the angle of inclination depends, among other things, on the distance of the nozzle strip from the surface of the web or material web. For short distances, for example up to 10 mm, the angle of inclination can be chosen larger. For large distances, for example over 25 mm, an angle of inclination in the range of 1° to 5° can be advantageous. The distances between the holes from one another 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 spaced apart from one another in the width extension (Y) of the nozzle strip. The rows can be arranged parallel or at an angle to one another. The length extension

Advantageously, the longitudinal axes of directly successive nozzle openings of a respective row can be mirrored in their orientation relative to a respective plane of symmetry arranged between two adjacent nozzle openings of the respective row or point-mirrored to a point of symmetry arranged therein, so that oblique bores are alternately mirrored from nozzle opening to nozzle opening within a row of the nozzle strip. For example, a symmetrical arrangement of individual nozzle openings that are 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 that are angled or orthogonal 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 within a row - viewed in the longitudinal direction of the row and thus in the length extension (X) of the nozzle strip - each spaced apart from one another by a distance X1.

According to a first alternative A of the invention, directly adjacent rows of nozzle openings are arranged offset from one another by half the distance X1 in the longitudinal direction of the row, i.e. viewed in the length extension (X), the distance directly adjacent rows are not directly opposite each other when viewed in the direction of the width extension (Y) of the nozzle strip. This achieves a high level 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 described up to this point, describes the longitudinal axes of immediately adjacent nozzle openings - including those across directly adjacent rows - as lines of a single-shell hyperboloid. Individual or all longitudinal axes of the nozzle openings arranged in this way of directly adjacent nozzle openings, even 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 fluid jets that create a swirl around a virtual center of the nozzle openings. This twist leads to better turbulence of the fibers and thus to increased solidification 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 - viewed in the longitudinal direction of the row and thus in the length extension (X) of the nozzle strip - are opposite the middle one row offset. The outer two rows are minimally offset from the inclination of the fluid jet at a distance from the nozzle openings. The offset refers to the distance between the center of the nozzle opening on the top of the nozzle strip and 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 is offset from the middle row by a distance of 0.5*X1-X2, whereby the distance X2 results from the following formula: 0 .5 times the height of the nozzle strip times the tangent of the inclination angle of the respective longitudinal axis of the nozzle opening. 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 when hitting the material web is due to the orientation of the longitudinal axes according to the invention is advanced compared to the arrangement as it is in a top view of the nozzle strip in the direction of application of the fluid (perpendicular to the XY plane). This corrects this so that the impact points on the material web are distributed more evenly, 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 - seen in the longitudinal direction of the row and thus in the length extension (X) of the nozzle strip - are each arranged spaced apart from one another by a distance X3, the nozzle openings being The remaining two rows within the row in question are alternately spaced apart by the distance 2*X3 and 4*X3, so that the nozzle openings of directly adjacent rows are not directly opposite one another when viewed in the direction of the width extension (Y) of the nozzle strip, and that individual nozzle openings are directly adjacent to one another Rows always have the same distance X3 from one another in the length extension (X) of the nozzle strip. This always results in equidistant distances from nozzle opening to nozzle opening, whereby the impact of the fluid jets on the material web is standardized and thus the turbulence along the entire web width of the material web is improved.

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

Preferably, the nozzles of the nozzle strip can be arranged so that in at least two rows of nozzles the nozzles form a square, rectangle or diamond, 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 to 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. Preferably, the swirl generated changes from nozzle arrangement to nozzle arrangement in a clockwise and counterclockwise direction.

Finally, the present invention also relates to a system for solidifying a material web, comprising at least one nozzle bar and one that conducts fluid 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 shown 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 system according to the invention;

Fig. 2a to 2d:

the alternatives A to D of the nozzle strip according to the invention in a section AA according to Fig. 1 ;

Fig. 3:

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

Fig. 4:

a sectional view according to section line A1-A1 in the Fig. 2a to 2d ;

Fig. 5:

a top view of a nozzle strip of a further embodiment;

Fig. 6:

an enlarged top view of the jet strip of the Figure 5 ;

Fig. 7:

a sectional view through the nozzle strip of the Figure 5 with the incident fluid jet on the material web.

Fig. 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 rotating 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 interchangeably. When the system 1 is operating as intended, the fluid under pressure 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, which are designed as oblique bores. The fluid forms a large number of fluid jets 6 at the outlet of the nozzle openings 5 from the nozzle strip 4. These act on the material web 2 passing underneath to hydrodynamically solidify it. Below the belt 7 there is a suction device 8 for removing the fluid penetrating the material web 2.

The representations of the Fig. 2a to 2d each show a sectional view of the nozzle strip according to section AA Fig. 1 the four different alternatives A to D of the invention mentioned at the beginning. This sectional view in the figures mentioned of the prismatic nozzle strip 4 also corresponds to the XY plane, where 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, i.e. for row R1 the nozzles 5.11, 5.12 and 5.13. As can be seen, the nozzle openings 5 are each in two ( Fig. 2d ) or three ( Fig. 2a to 2c ) - here arranged in parallel rows. The arrows following the circles should represent the longitudinal axes L of the respective nozzle openings 5: Since the nozzle openings 5 are designed as oblique bores, one must 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, in Fig. 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 vertical (lower part) is also indicated.

In the representations of the Fig. 2a to 2c You can see three rows R1, R2, R3 of nozzle openings 5. The nozzle openings 5.21 - 5.24 of the middle row R2 are in the Figs. 2a and 2b always spaced apart by a distance X1. In Fig. 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 length X of the nozzle strip 4 by half the distance X1 from the middle row R2. 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 Fig. 2a to 2d It is noticeable that the orientations of the nozzle openings 5 alternate in one and the same row from nozzle opening 5 to nozzle opening 5. This can be seen, for example, in the first row R1 of nozzle openings 5 on the opposite longitudinal axes L of two directly adjacent nozzle openings 5.11 and 5.12 or 5.12 and 5.13 (see e.g Fig. 2a ). If you look at the directly adjacent nozzle openings 5 of directly adjacent rows, it is noticeable that their orientations in space are also different. For example, the longitudinal axes L of the directly adjacent nozzle openings (even across the rows) are always skewed to one another. This can be seen in the orientations of the arrows, which can be considered vectors:

These are arranged "rotating" in a clockwise direction. According to the illustration in Fig. 2a This is achieved by defining the nozzle 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 partly shown as lines of a single-shell hyperboloid (see bold solid lines in Fig. 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 created from 90 ° rotations of the longitudinal axis L of the nozzle opening 5.11 about this center 5.5. This special symmetrical arrangement gives the fluid jets emerging from the nozzle openings 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 , with an excessive number of longitudinal axes shown here). If you look in the Fig. 2a further to the right, then you will notice that the neighboring 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. Through this special arrangement and orientation of the longitudinal axes L of the nozzle openings 5, as is also protected by claims 3 to 5, a particularly advantageous swirling of the fibers of the material web 2 can be achieved by entraining them as a result of the swirling fluid jets 6. This significantly increases the strength of the hydrodynamically consolidated material web 2.

In the representations of the Fig. 2b and 2c These are the above-described alternatives B and C of the nozzle strip 4. The first and second rows are offset from the middle row in the longitudinal direction X in accordance with the features of claims 7 and 8. This is done in order to achieve a more homogeneous impact pattern ("image") of the fluid jets 6 as a result of the nozzle openings 5 now being arranged equidistant from one another on the material web 2 and thus a more uniform and improved swirling over the entire length of the nozzle strip 4 and thus over the width of the material web 2 to achieve. In Figure 2b When three rows R1, R2, R3 are provided at nozzle openings 5, the nozzle openings of the first and third rows 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 extension (X) of the Jet strip seen - offset from the middle row R2.

The outer two rows R1, R3 are minimally offset from the inclination of the fluid jet 6 at a distance X1 from the nozzle openings 5. The offset refers to the distance between the center of the nozzle opening on the top of the nozzle strip and the center of the nozzle opening on the bottom of the nozzle strip. The first row R1 is offset from the second and middle row R2 by a distance of 0.5*X1+X2 and the third row R3 by a distance of 0.5*X1-X2, with the distance X2 increasing The following formula results in: 0.5 times the height of the nozzle strip 4 times the tangent of the inclination angle of the respective longitudinal axis 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 striking the material web 2 due to 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 direction of application of the fluid (perpendicular to the XY plane), is advanced. This corrects this so that the impact points on the material web 2 are more evenly distributed, which in turn results in improved turbulence.

In Figure 2c the third alternative C of the invention is described when providing three rows of nozzle openings 5. 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 extension (X) of the nozzle strip - are each at a distance of 3x X3 from one another. The center 5.5 of a swirling unit is now formed by nozzles 5.11, 5.22, 5.31, 5.21 arranged offset from one another, which are arranged in the longitudinal direction X of the nozzle strip 4 by the distance X3. 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 arranged alternately at a distance of 1x X3 and 3x X3, so that the nozzle openings of directly adjacent rows R1, R2; R2, R3 are not directly opposite each other when viewed in the direction of the width extension (Y) of the nozzle strip, and that individual nozzle openings in directly adjacent rows always have the same distance X3 from one another when viewed in the length extension (X) of the nozzle strip. This always results in equidistant distances from nozzle opening to nozzle opening, whereby the impact of the fluid jets on the material web is standardized and thus the turbulence along the entire web width of the material web is improved.

Finally, the representation shows the Fig. 2d the alternative D of the nozzle strip 4 according to the invention described at the beginning. It is a further development of alternative C Fig. 2c . The nozzle openings 5 of the middle row R2 have been moved one after the other and alternately into the first row R1 or third row R3, which lie on both sides 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 impact of the fluid jets on the material web 2.

Figure 3 shows the effect of the fluid jets 6 striking a material web 2 through the arrangement of the nozzle openings 5. Due to the arrangement according to the invention Nozzle openings 5 create a swirl around a virtual center 5.5 of the nozzle openings. This twist leads to better turbulence of the fibers and thus to increased solidification 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 described up to this point, describes the longitudinal axes L of immediately adjacent nozzle openings - including those across directly adjacent rows - as lines of a single-shell hyperboloid. Individual or all longitudinal axes of the nozzle openings arranged in this way of directly adjacent nozzle openings, even across directly adjacent rows, are thus arranged in such a way that they form parts of the lines of a hyperboloid. This arrangement creates a swirl of fluid jets 6 without any component having to rotate.

Figure 4 shows a section through a nozzle opening 5 along the section plane A1-A1 from the 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, relative to a perpendicular to an XY plane, which is spanned by the width and length extension of the nozzle strip ° inclined to 5°. This angle has proven to be particularly advantageous in order to generate particularly favorable swirling of the fibers of the material web 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 spaced apart from one another in the width extension (Y) of the nozzle strip. The rows can be arranged parallel or at an angle to one another. The length X of the nozzle strip essentially corresponds to the width of the material web 2.

In a further exemplary embodiment 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 hit. The nozzles of the first 5.11, 5.12 and second row 5.21, 5.22 have a distance in the X direction of X1. The distance between the rows of nozzles is X3. The distances X1 and Or In other words, the fluid jets 6 strike tangentially on a virtual path of a circle or an ellipse, which lies in the plane of the material web 2. If the distances X1 and The fluid jets 6 create a clockwise or counterclockwise twist in the plane of the material web 2, with which the fibers intertwine with one another in addition to the known swirling. The effect is contrary to the previous orientation of the fibers, which are arranged on one side in the production direction (MD direction) in accordance with the production direction of the material web 2 in the MD/CD ratio. By arranging or impinging the fluid jets 6 on the virtual circular path, the alignment of the fibers in the MD/CD ratio in the material web 2 is evened out, and at the same time the strength of the material web 2 is increased due to the swirling swirling of the fibers among themselves. In the exemplary embodiment Figure 5 The groups of nozzles alternately produce a clockwise or counterclockwise twist on the material web 2. The cutting plane AA is 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 strip 4 and the surface of the material web 2, by the inclination angle α of the nozzle opening in the nozzle strip 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. The virtual circle can also be arranged asymmetrically within the rectangle X1, X3, in which the angles β or γ and δ are varied. The angle δ represents the orientation of the fluid jet 6 or the inclination of the nozzle opening 5 to the center of the virtual circle or the ellipse. The angle β represents the orientation 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 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, i.e. to the Z direction. The angles β and γ together form a right angle.

The alignment of the nozzle openings 5 according to 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 according to the Figures 5 to 7 takes place within a rectangle or square of nozzles 5.11, 5.12, 5.21, 5.22, and are all directed inwards towards a virtual circle, with the rays hitting the virtual circle tangentially. Seen in the Z direction, four nozzles 5.11, 5.12, 5.21, 5.22 are inclined to 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 swirl 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 the Figure 5 a counterclockwise twist. The 4 neighboring rays in the middle of Figure 5 are inclined in such a way that a counterclockwise twist is created. The other four nozzles 5.15, 5.16, 5.25, 5.26 in Figure 5 in turn create a clockwise twist. The twist direction is therefore seen alternately in the direction of the working width or longitudinal axis of the nozzle bar 3 (X direction).

Transferred to the exemplary 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 with 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, whereby the points struck by the fluid jets on the virtual circle or ellipse in the plane of the material web lie within this geometric shape in order to achieve the desired To create a swirl effect.

Preferably, four nozzles from two rows of nozzles 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 so that the impact points 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 exemplary embodiments Figures 5 to 7 smaller than dimension X1, at least 0.5 mm. If the diameter of the virtual circle becomes smaller, no significant swirl is generated at these dimensions because 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 produce particularly favorable swirling of the fibers of the material web. The size of the angle of inclination depends, among other things, on the distance of the nozzle strip from the surface of the web or material web. For short distances, for example X4 to 10 mm, the angle of inclination can be chosen larger. For large distances, for example X4 > 25 mm, an angle of inclination in the range of 1° to 5° can be advantageous. Of course, the distances between the nozzle openings and one another also play a role here. According to the invention, additional swirling and thus knotting of the fibers or filaments is achieved, so that the integration of fibers or filaments on the fleece surface is improved. The material web becomes more isotropic, at least on the surface, and thus the strength or the MD/CD ratio is evened out.

Reference symbols

1

Attachment

2

material web

3

nozzle bar

4

jet strips

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 nozzle

X, Y, Z

Longitudinal, width and height extent of the jet strip

X1

Distance between nozzles in a row

X2

Offset from nozzle inlet to nozzle outlet

X3

Distance between nozzles in different rows

X4

Distance of the material web from the nozzle strip

X5

Distance between nozzles in a row

A-A

cutting plane

R1-R3

row of nozzles

α

Angle of inclination

β

Angle of inclination

γ

Angle of inclination

δ

Angle of inclination

Claims (14)

1. Nozzle strip (4) for generating fluid jets (6) for the hydrodynamic entanglement of a sheet of material (2), having a plurality of nozzle openings (5) which are arranged spaced apart from one another in at least two rows (R1, R2, R3) and are to deliver the fluid jets (6) to the sheet of material (2), wherein the nozzle openings (5) have been introduced into the nozzle strip (4) in the form of angled holes, so that the fluid jets (6) emerge from the nozzle strip (4) along the longitudinal axes (L) of the nozzle openings (5), wherein the nozzle strip (4) is configured in such a manner that the longitudinal axes (L) of directly adjacent nozzle openings (5) of the same row and the longitudinal axes (L) of directly opposite nozzle openings (5) of directly adjacent rows in each case run skew to one another.
2. Nozzle strip (4) according to claim 1, characterised in that the nozzle strip (4) has a length extent (X), a width extent (Y) and a height extent (Z), and the longitudinal axes (L) of the corresponding nozzle openings (5) are inclined relative to a perpendicular to an XY plane which is spanned by the width and length extent of the nozzle strip (4) by an angle of inclination (α) of from 1° to 20°, preferably by from 1 to 10°, particularly preferably by from 1 to 5°, wherein preferably the at least two rows are arranged spaced apart from one another in the width extent (Y) of the nozzle strip (4).
3. Nozzle strip (4) according to claim 1 or 2, characterised in that the longitudinal axes (L) of nozzle openings (5) of a row that follow one another directly are mirrored in their orientation relative to a respective plane of symmetry arranged between two adjacent nozzle openings (5) of the row in question or are mirrored pointwise about a point of symmetry arranged in said plane, so that there are obtained angled holes of the nozzle strip (4) which are oriented in an alternately mirrored manner from nozzle opening (5) to nozzle opening (5) within a row.
4. Nozzle strip (4) according to claim 2 or 3, characterised 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 preferably are both perpendicular to the XY plane.
5. Nozzle strip (4) according to any one of claims 1 to 4, characterised in that the nozzle openings (5) within a row - when seen in the longitudinal direction of the row and thus in the length extent (X) of the nozzle strip (4) - are in each case arranged spaced apart from one another by a distance (X1).
6. Nozzle strip (4) according to any one of claims 2 to 5, characterised in that directly adjacent rows of nozzle openings (5), when seen in the longitudinal direction of the row, that is to say in the length extent (X), are arranged offset relative to one another by half the distance (X1), 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, when seen in the direction of the width extent (Y) of the nozzle strip (4), are not located directly opposite one another.
7. Nozzle strip (4) according to claim 6, characterised in that, where 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) - when seen in the longitudinal direction of the row and thus in the length extent (X) of the nozzle strip (4) - are offset relative to the middle row (R2), wherein the first row (R1) is arranged offset by a distance of 0.5*X1+X2 and the third row (R3) is arranged offset by a distance of 0.5*X1-X2 relative to the second middle row (R2), wherein the distance X2 is given by the following formula: 0.5 times the height of the nozzle strip (4) times the tangent of the angle of inclination of the longitudinal axis (L) of the nozzle opening (5).
8. Nozzle strip (4) according to any one of claims 2 to 4, characterised in that, where three rows of nozzle openings (5) are provided, the nozzle openings (5) within the middle row (R2) - when seen in the longitudinal direction of the row and thus in the length extent (X) of the nozzle strip (4) - are arranged spaced apart from one another in each case by a distance n*X3, wherein the nozzle openings (5) of the other two rows (R1, R3) are spaced apart from one another within the row in question alternately by the distance (n-1)*X3 and (n+1)*X3, so that the nozzle openings (5) of directly adjacent rows, when seen in the direction of the width extent (Y) of the nozzle strip (4), are not located directly opposite one another, and in that individual nozzle openings (5) of directly adjacent rows are always at the same distance X3 from one another when seen in the length extent (X) of the nozzle strip (4), wherein n is preferably three.
9. Nozzle strip (4) according to claim 8, characterised in that individual or all the nozzle openings (5) of the middle row are alternately displaced along the width extent (Y) of the nozzle strip (4) towards one of the two rows.
10. Nozzle strip (4) according to claim 1 or 2, characterised in that, in at least two rows (R1, R2, R3) of nozzles, the nozzles form a square or rectangle, wherein the longitudinal axes (L) of the nozzles are oriented at points of a virtual circle, on the plane of the sheet of material (2), that is arranged within the square or rectangle.
11. Nozzle strip (4) according to claim 10, characterised in that at least four nozzles (5.11, 5.12, 5.21, 5.22) from two rows (R1, R2) are oriented tangentially to a virtual circle which lies inside the arrangement of the at least four nozzles (5.11, 5.12, 5.21, 5.22) in the plane of the sheet of material (2).
12. Nozzle strip (4) according to either claim 10 or claim 11, characterised in that each nozzle is arranged at an angle (δ) which is formed between a line connecting the nozzle to the centre (5.5) of the virtual circle and a tangent from the nozzle to the virtual circle in the plane of the sheet of material (2).
13. Nozzle strip (4) according to either claim 10 or claim 11, characterised in that the inclination of each nozzle is arranged at an angle (β) and (γ), wherein the angle (β) is given by the inclination of the nozzle opening (5) relative to the longitudinal axis of the nozzle beam (3), that is to say relative to the X-direction, and the angle (γ) is given by the inclination of the nozzle opening (5) relative to the production direction, that is to say relative to the Z-direction.
14. Installation (1) for the entanglement of a sheet of material (2), comprising at least one nozzle beam (3) and a nozzle strip (4) which can be connected thereto in a fluid-conducting manner for generating fluid jets (6) for the hydrodynamic entanglement of the sheet of material (2), wherein the nozzle strip (4) is configured according to any one of the preceding claims.

Images