CN116528985A - Water jet beam for generating a fluid jet for hydraulically stiffening a material web and device for stiffening a material web - Google Patents

Abstract

The invention relates to a water jet beam for generating a fluid jet for hydraulically reinforcing a material web, having a plurality of jet openings for applying the fluid jet to the material web, which jet openings are arranged at a distance from one another along the length extension of the water jet beam, wherein the underside of the water jet beam facing the material web has a parting surface which, viewed in the width extension of the water jet beam, is inclined away from the material web on both sides of the jet openings, such that a wedge-shaped free space is obtained between the underside of the water jet beam and the material web, wherein the wedge-shaped free space tapers, viewed in the width extension of the water jet beam, toward the jet openings, characterized in that the angle of inclination of the parting surface of the underside of the water jet beam is between 5 DEG and 25 deg. The invention further relates to a device for reinforcing a material web, comprising at least one water jet for generating a fluid jet for hydraulically reinforcing the material web, wherein the water jet is configured according to the invention.

Description

Water jet beam for generating fluid jets for hydraulically reinforcing material webs and reinforcement Equipment for solid material webs

technical field

The invention relates to a water jet beam for generating a fluid jet for the hydraulic reinforcement of a material web and a device for consolidating such a material web, said device comprising such a water jet beam.

Background technique

Such devices are used for the hydroentangling of material webs, for example formed from fibres. Thus, with the aid of the invention, it is possible to consolidate nonwovens from natural fibers, synthetic fibers and spunbond nonwovens from low nonwoven weights to relatively high nonwoven weights. In addition, material webs can be structured and/or perforated with such water jet beams.

DE 202008004650U1 and DE 102010004172A1 disclose such devices by way of example. That is, a water jet beam having a large number of spray holes is respectively provided. The nozzle openings are arranged one after the other in a row, for example along the length extension of the jet beam. In this case, the underside of the water jet beam, ie the side facing the material web, is beveled on both sides of the outlet of the spray opening. This ramp can also be covered by boards.

The disadvantage of these devices is that, despite the slope, the air entrained by the material web passing over the water jet beams leads to eddy currents in the region of the underside of the water jet beams. As a result, the fluid jets emerging from the water jet beams are disrupted, affecting the strength of the material web.

Contents of the invention

It is therefore the object of the present invention to provide a water jetting beam and a device for reinforcing a material web, by means of which water jetting beam/device can further improve the strengthening of such a material web. In particular air turbulence on the underside of the water jet beam should be avoided.

The object underlying the invention is solved by a water jet beam and a corresponding device for reinforcing a material web. Preferred embodiments of the invention are given in the dependent claims,

These dependent claims can be optionally combined with each other.

The water jet beam according to the invention for generating a fluid jet for the hydraulic reinforcement of a material web has a plurality of nozzle openings for applying the fluid jet to the material web. The spray holes are spaced apart from each other along the length extension of the water jet beam. In this case, the underside of the jet beam facing the material web has a parting surface which is inclined away from the material web on both sides of the nozzle orifice, as seen in the width extension of the jet beam. This results in a wedge-shaped free space on the underside of the jet beam, ie between the parting surface and the material web. The wedge-shaped free space tapers towards the nozzle opening as seen along the width extension of the jet beam.

The water jet beam can be configured prismatically and, in addition to a length extension (Y) and a width extension (X), also extends in height (Z). The names X,Y,Z correspond to the same axis names in the Cartesian coordinate system. Seen in the installed state of the water jet beam, the length extension Y of the water jet beam corresponds to the width of the material web and the width extension X of the water jet beam instead corresponds to the length of the material web.

In principle, the water beam can be divided into an upper part and a lower part. The features according to the invention associated with the inclined parting surface can be realized in the lower part. This has the advantage that the lower part can be easily replaced without also having to dismantle the upper part.

If the angle of inclination of the parting surface of the underside of the water jet beam is now selected between 5° and 25°, the air turbulence within this wedge-shaped free space is surprisingly significantly reduced. As a result, the influence on the fluid jet emerging from the spray opening is reduced, so that the consolidation of the material web is significantly improved. In addition, the underside of the jet beam can now be brought closer to the material web.

In other words, the angle of inclination of the parting surface - in the view of the line of sight of the length extension of the water jet beam - is defined by the tangent of the parting surface and the parallel line or material web of the width extension of the water jet beam angle. In this case it is always the smallest angle that the two together enclose.

A web of material referred to in the present invention means a web of fibrous material made of fibres. Such a fibrous web can be in the form of a woven, knitted or non-woven fabric and preferably comprises the fibers mentioned at the outset.

The longitudinal axis of the orifices means the axis of symmetry of these orifices. Since these axes essentially correspond to the direction of application of the fluid jet, the statements regarding the longitudinal axis basically also apply to the fluid jet itself.

The advantages according to the invention are achieved particularly well when the angle of inclination is between 7° and 10° and preferably 10°.

A particularly effective reinforcement of the material web is achieved when the longitudinal axes of the individual spray openings are aligned with the material web in such a way that the fluid jets strike the material web perpendicularly.

In principle, the parting surface of the underside of the jet beam can be an inclined plane, a curved surface according to the radius type or a free-form surface type. In this case, the angle of inclination (preferably at each point along the course of the curved surface) is between the tangent to the curved surface and the parallel line to the width extension of the water jet beam in a view of the line of sight to the length extension of the water jet beam time measurement. A free-form surface means a surface established by means of splines (Splines), wherein a spline refers to a polynomial parametric curve whose function is composed of n-order polynomial segments.

According to one embodiment of the invention, the underside of the jet beam in the outlet region of the fluid jet has outlet surfaces on both sides of the nozzle opening, wherein the individual outlet surfaces adjoin the respective outlet surface indirectly or directly by means of a transition surface. parting surface. A face indirectly adjoins another face is understood to mean that this face adjoins the other face with the other faces being connected therebetween. Directly adjoining means that there are no further intermediate surfaces and that the two surfaces therefore share, for example, a common edge. A drip edge can thus be realized as described below.

It is advantageous if the transition surface adjoins the parting surface indirectly via an end surface, wherein the end surface preferably extends parallel to the longitudinal axis of the injection opening. The transition surfaces preferably each run at right angles to the longitudinal axis of the nozzle openings, viewed from the length extension of the jet beam. Preferably, the cover sheet can be placed at least on the parting surface or the entire underside, preferably along the course of the parting surface or the entire underside, and preferably supports the bordering end faces of the cover sheet on the end faces. The cover plate can therefore preferably be supported with pretension on the aforementioned end faces of the water jet beam. This simplifies the assembly of the cover plate and at the same time simplifies the structural outlay on the water jet beam, since the cover plate now requires no other means, such as additional bolts on the water jet beam, to support it in this position.

The end face and the transition face can preferably together delimit a drip edge of a fluid drop of the fluid jet. Thus, a cleaning effect of the cover plate can be achieved, for example, by means of the fluid reflected by the material web.

According to one embodiment of the invention, the underside of the water jet beam facing the material web and preferably, if the covering sheet according to the invention is provided, the surface of the covering sheet facing the material web can have an average roughness of 1 μm to 50 μm, preferably 25 μm Spend. The surface of the cover plate can preferably be sandblasted, eg glass bead blasted. The fluid (for example water) which realizes the fluid jet thus remains attached to the surface of the cover plate as a thin film. As a result, the material web does not dry out the fiber deposits that reach the cover sheet by the water jet during the hydroentanglement. Thus, the fibers can be removed by the film from the outer surface of the cover plate without adhering thereto. Thus, excessive accumulation of fibers that may fall onto the material web can be prevented.

Furthermore, the invention relates to a device for reinforcing a material web, comprising at least one water jet beam for generating a fluid jet for the hydraulic strengthening of the material web, wherein the water jet beam is designed according to the invention.

Description of drawings

Further measures for improving the invention are explained in more detail below together with the description of preferred exemplary embodiments of the invention with reference to the drawings.

In the picture:

Figure 1 shows an embodiment of the device according to the invention;

FIGS. 2 to 4 each show an embodiment of a water jet beam according to the invention in section A-A according to FIG. 1 .

Detailed ways

FIG. 1 shows a rather schematic, partly cut-away side view of a device 1 according to the invention for reinforcing a material web 2 , which comprises a water jet beam 4 according to the invention. The material web 2 is transported on an endless conveyor belt 3 and consolidated by means of fluid jets 6 . In the present case, the fluid jet 6 strikes the material web 2 perpendicularly. As shown, the water jet beam 4 may be prismatic and have a width extension in the X direction, a length extension in the Y direction and a height extension in the Z direction. In this exemplary embodiment, the jet beam 4 has a single row of spray openings 5 , which are now spaced parallel to one another in the length extension (Y direction). According to the invention, multiple rows of spray openings 5 can also be provided. The water jet beam 4 is connected in a flow-conducting manner to a fluid (eg water) container, for example with a pump (not shown) connected in between. Thus, in normal operation of the plant 1 , the fluid under pressure reaches the jetting beam 4 . From there, the fluid is expelled by a plurality of nozzle openings 5 arranged in the jet beam 4 . The fluid forms a plurality of fluid jets 6 from the jet beam 4 at the outlet of the nozzle opening 5 . These fluid jets act on the underlying passing material web 2 in order to hydraulically stiffen said material web. Below the conveyor belt 3 is arranged a withdrawal device 7 for discharging the fluid passing through the material web 2 . The water beam 4 can be assembled from two parts, an upper part and a lower part, which can be separated and assembled along the tangent line A-A. The lower part can be fastened to the upper part by means of screws, for example.

The illustrations in FIGS. 2 to 4 each show the lower part of the water jet beam 4 below the tangent line A-A in FIG. 1 in three different embodiments of the invention in a partial sectional view (in the XZ plane). In this case, the jet beams 4 are each configured symmetrically with respect to the longitudinal axis L of the nozzle opening 5 . The plane of symmetry may be a plane parallel to the YZ plane, which plane passes through the longitudinal axis L.

It can be seen in the illustration that the underside of the jet beam 4 , ie the side facing the material web 2 , has an obliquely shaped parting surface 8 . The parting surface 8 is inclined away from the material web 2 as seen along the width extension X. In the illustration of FIG. 2 , the parting surface 8 extends in a plane that extends at an angle to the XY plane.

The parting surface 8 is defined as the surface that adjoins the outlet surface 11 of the water jet beam 4 via the transition surface 10 . In this case, the outlet surface 11 is the surface in the region in which the fluid jet 6 exits from the nozzle opening 5 . In other words, it is the surface that defines the injection hole 5 . Viewed away from the spray opening 5 , ie seen along the width extension (X-axis), the transition surface 10 adjoins the outlet surface 11 , which can run, for example, parallel to the X-axis or to the material web 2 . Viewed along this line of sight, the parting surface 8 then directly adjoins the transition surface 10 . Further parting surfaces of different inclinations adjoin the parting surface 8 as seen along the line of sight.

As shown in FIGS. 2 to 4 , the parting surface 8 and the material web 2 together delimit a wedge-shaped free space 9 . In this case, the wedge-shaped free space 9 tapers toward the spray opening 5 as seen in the width extension of the jet beam 4 (in the X direction).

In principle, the parting surface 8 can not only be a plane, but also a curved surface according to the radius type or free-form surface type. The inclination angle α representing the inclination of the parting surface 8 can be understood as the angle between the tangent of the parting surface 8 viewed in the XZ plane and the parallel line (such as the X axis or material web) of the width extension of the water beam 4 angle.

If the angle of inclination α is now selected in the embodiment of the invention in FIGS. 2 to 4 such that it lies between 5° and 25°, the air turbulence in the wedge-shaped free space 9 can be reduced. These air turbulences are produced, for example, by entrainment of air by the material web 2 passing below the jet beam 4 . According to the invention, the impact on the fluid jet 6 emerging from the water jet beam 4 is reduced due to the reduced air turbulence. Thus, a higher reinforcement of the material web 2 can be achieved. This effect is particularly noticeable when the inclination angle α is set to 10°.

FIG. 3 shows an extension of the technical solution of FIG. 2 . The transition surface 10 protrudes there, ie the transition surface extends towards the material web 2 . The end face 13 is thus formed on its side, so that the parting surface 8 now no longer directly adjoins the transition face 10 , but adjoins it via the end face 13 . The edge delimiting the transition surface 10 and the end surface 13 can now serve as a drip edge. Fluid reflected by the material web 2 or the conveyor belt 3 can drip off at the dripping edge. The distance between the transition surface (10) and the parting surface (8) can be 0.5 mm to 5 mm, preferably 0.5 mm to 3 mm.

In FIG. 4 the water jet beam 4 of FIG. 3 is shown. On its outer side facing the material web 2 a cover plate 12 is attached. The latter is designed in such a way that it bears with its inner side against the outer side of the jet beam 4 facing the material web 2 and rests against the parting surface 8 of the jet beam. The cover plate 12 can be used to cover the threaded holes of the bolts for fastening the lower part of the jet beam 4 to the upper part. In this case, the front end of the boundary of the cover plate 12 bears against the end face 13 with a pretension. The end face 13 thus holds the boundary, ie the edge of the cover plate 12 , without having to be supported at this end by other means, such as additional bolts on the jet beam 4 . At the transition from the inclined parting surface 8 perpendicular to the Z direction, parallel to the longitudinal axis L, the cover plate 12 has a rounded transition 14 or a larger radius, arc or polygon. Drip edges are therefore avoided at these points, which are undesirable here. The radius of the transition 14 is at least 5 mm.

The outer side of the cover plate 12 facing the material web 2 can be provided with a certain surface roughness. Thus, for example, with an average roughness Rz of between 1 μm and 50 μm, preferably 25 μm, a hydrophilic surface can be provided on which the fluid remains attached as a film and the formation of large droplets is avoided. The fluid film drips in the form of small droplets at the transition between the parting surface 8 and the transition surface 10 . Due to the continuous wetting of the above-mentioned outer surface of the cover plate 12 by the fluid, the fibers splashed from the material web 2 can be better removed from this outer surface, so that impurities are less likely to adhere to the cover plate 12 .

In another embodiment, the end face 13 can be displaced towards the outlet face 11 so that the transition face 10 becomes smaller. The distance between the outlet surface 11 and the end surface 13 can be, for example, 0.5 mm to 2 mm. At the same time, the transition surface 10 can protrude toward the material web 2 by 0.5 mm to 5 mm, preferably by 0.5 mm to 3 mm. Thus, a drip edge is formed in the vicinity of the fluid jet 6 .

List of reference signs

1 device

2 material format

3 conveyor belts

4 water beams

5 nozzles

6 fluid jet

7 Extractor

8 parting surface

9 wedge-shaped free space

10 transition surface

11 Exit side

12 cover plate

13 end faces

14 Transition

L Longitudinal axis of nozzle hole

X,Y,Z width extension, length extension and height extension of water beam

α tilt angle

Claims (14)

1. Water jet beams (4) for generating fluid jets (6) for hydrodynamically reinforcing material webs (2), with a large number of orifices (5) for applying the fluid jets (6) On the material web (2), the nozzle openings are arranged at a distance from one another along the length extension of the water jet beam (4), wherein the underside of the water jet beam (4) facing the material web (2) has a parting Viewed from the width extension of the water jet beam (4), the parting surface is inclined away from the material web (2) on both sides of the nozzle hole (5), so that the underside of the water jet beam (4) is in contact with the material A wedge-shaped free space is obtained between the webs (2), wherein the wedge-shaped free space (9) tapers towards the nozzle opening (5) as viewed along the width extension (X) of the water jet beam (4), its characteristic In that, the inclination angle (α) of the parting surface (8) on the underside of the water jet beam (4) is between 5° and 25°. 2. The water jet beam (4) according to claim 1, characterized in that, the inclination angle (α) is 10°. 3. The water jet beam (4) according to claim 2, characterized in that the longitudinal axes of the individual spray holes (5) are aligned with respect to the material web (2) such that the fluid jets (6) hit the on the material web (2). 4. The water beam (4) according to one of claims 1 to 3, characterized in that the parting surface (8) on the underside of the water beam (4) is an inclined plane, a A curved surface of radius type or freeform surface type and the angle of inclination (α) is measured between the tangent of the curved surface and the parallel line of the width extension (X) of the jet beam (4). 5. The water jet beam (4) according to one of claims 1 to 4, characterized in that the underside of the water jet beam (4) is located between the spray holes (5) in the exit region of the fluid jet (6). The sides each comprise an outlet surface (11), wherein each outlet surface (11) adjoins the corresponding parting surface (8) indirectly or directly via a transition surface (10). 6. The water jet (4) according to claim 5, characterized in that the transition surface (10) indirectly adjoins the parting surface (8) via an end surface (13), wherein the end surface (13) is preferably parallel to the jet The longitudinal axis (L) of the hole (5) extends. 7. Water jet beam (4) according to claim 5 or 6, characterized in that the cover plate (12) is placed on at least the parting surface (8) or the entire underside or the cover plate is a placeable At least on the parting surface (8) or the entire underside, the cover sheet preferably follows the course of the parting surface (8) or the entire underside and preferably supports the boundary of the cover sheet (12) on the end face (13) end side. 8. The water jet beam (4) according to claim 6 or 7, characterized in that the end surface (12) and the transition surface (10) jointly define a dripping edge where the fluid of the fluid jet (6) drops. 9. The water jet beam (4) according to one of claims 1 to 8, characterized in that the underside of the water jet beam (4) facing the material web (2) and preferably at the The cover sheet ( 12 ) described above has an average roughness of 1 μm to 50 μm, preferably 25 μm, on the surface of the cover sheet ( 12 ) facing the material web ( 2 ). 10. The water jet beam (4) according to claim 9, characterized in that the surface of the cover plate (12) is preferably sand blasted, especially glass bead sand blasted. 11. The water jet beam (4) according to one of claims 7 to 10, characterized in that the cover plate (12) is perpendicular to the Z direction from the inclined parting surface (8), parallel to the longitudinal axis ( The transition of L) has a rounded transition ( 14 ), which is configured as a radius, arc or polygon. 12. The water jet beam (4) according to claim 6, characterized in that the distance between the end face (13) and the outlet face (11) is 0.5 mm to 2 mm. 13. The water jet beam (4) according to any one of claims 6 to 12, characterized in that the distance between the transition surface (10) and the parting surface (8) is 0.5 mm to 5 mm, preferably 0.5 mm to 3 mm. 14. A device (1) for reinforcing a material web (2), comprising at least one water jet beam (4) for generating a fluid jet (6) for hydraulically reinforcing the material web (2), wherein the water jet The beam (4) is constructed according to one of the preceding claims.