Extruded paper machine clothing and method for the production thereof

Abstract

A clothing for a machine producing and/or processing a fibrous web extending in longitudinal and widthwise directions, includes a basic structure providing dimensional stability in longitudinal and/or widthwise directions. The structure includes a band-shaped, one-piece grid having widthwise-adjacent first material strands and polymer material having lengths in a longitudinal direction, and adjacent second interconnected material strands and/or droplets and polymer material, contacting the first strands at contact points forming the grid. The strands and/or droplets are deposited by extrusion of the polymer materials in liquid or pasty state onto a depositing surface forming a portion or all of the grid in liquid or pasty state, the polymer materials are solidified, converting the portion or the grid from liquid or pasty to solidified, stable, self-supporting state producing bonding at the contact points, and removing the portion or the grid from the surface.

Claims

1. A clothing to be used in a machine for at least one of producing or processing a fibrous web extending in lengthwise and widthwise directions, the clothing comprising: a basic structure substantially providing dimensional stability of the clothing in at least one of the lengthwise or widthwise directions when used as intended, said basic structure having a band-shaped, one-piece grid structure with an upper side being a paper contacting side and an underside being a machine contacting side; said grid structure including a plurality of first material strands disposed next to one another in the widthwise direction of the clothing and a first polymer material, said first material strands having a length extending substantially in the lengthwise direction of the clothing, and a plurality of at least one of second material strands or drops disposed next to one another and a second polymer material; said at least one of second material strands or drops directly contacting said first material strands at contact points and being connected to one another causing said first material strands and said at least one of second material strands or drops to form said grid structure together; and said grid structure having characteristic of having been produced by: a) depositing said first material strands and said at least one of second material strands or drops in a liquid or pasty state by extrusion of said first and second polymer materials in a liquid or pasty state onto a depositing surface to form at least one portion of said grid structure or to form said grid structure, b) solidifying said first and second polymer materials by transforming said at least one portion of said grid structure or said grid structure from a liquid or pasty state into a solidified stable and self-supporting state and establishing a material-bonded connection at said contact points, and c) removing said at least one portion of said solidified grid structure or said grid structure from the depositing surface.

2. The clothing according to claim 1, wherein at least one of: said first material strands or said at least one said second material strands or drops, are formed of at least 60% by weight of said polymer material.

3. The clothing according to claim 1, wherein at least one of: said first material strands or said at least one said second material strands or drops, are formed of at least 80% by weight of said polymer material.

4. The clothing according to claim 1, wherein said lengths of said first material strands extend in a straight line.

5. The clothing according to claim 1, wherein: said grid structure is continuously closed in the lengthwise direction of the clothing; and each of said first material strands runs helically along its length with turns running around in a lengthwise direction of said basic structure and progressing in a widthwise direction of said basic structure.

6. The clothing according to claim 1, wherein: said grid structure is continuously closed in the lengthwise direction of the clothing; each of said first material strands forms a loop in its length running around in a closed manner in the lengthwise direction of the clothing; and said loops are individually disposed next to one another in a widthwise direction of said basic structure.

7. The clothing according to claim 1, wherein: said basic structure is open in the lengthwise direction of the clothing and has two ends, a transverse edge at one of said ends and a transverse edge at the other of said ends; each of said first material strands extends along its length over a length of said basic structure; and said basic structure includes, in addition to said grid structure, a seam connecting device for making said basic structure continuous by bringing together and interconnecting said transverse edges of said grid structure at said seam connecting device.

8. The clothing according to claim 1, wherein at least some of said at least one of second material strands or drops extend between said first material strands without crossing said first material strands, or at least some of said second material strands cross said first material strands.

9. The clothing according to claim 8, wherein said at least some of said second material strands cross said first material strands at right angles.

10. The clothing according to claim 1, wherein said first and second polymer materials are the same polymer material or said first and second polymer materials are different polymer materials.

11. The clothing according to claim 1, wherein at least one of said first material strands or said second material strands contains at least one respective yarn having at least some portions being at least partially enclosed by said first or second polymer material.

12. The clothing according to claim 1, wherein said grid structure has a smaller width than said basic structure or said grid structure has the same width as said basic structure.

13. The clothing according to claim 1, wherein said grid structure has a smaller width than said basic structure and said grid structure runs in a helically wound manner with turns running around in a lengthwise direction of said basic structure and progressing in a widthwise direction of said basic structure.

14. A process for producing a clothing for a machine for at least one of producing or processing a fibrous web, the process comprising the following steps: providing the clothing with a basic structure substantially providing dimensional stability of the clothing in at least one of a lengthwise direction or a widthwise direction when used as intended; providing the basic structure with a band-shaped, one-piece grid structure including an upper side being a paper contacting side, an underside being a machine contacting side, a plurality of first material strands disposed next to one another in the widthwise direction of the clothing, having a first polymer material and having a length extended substantially in the lengthwise direction of the clothing, and a plurality of at least one of second material strands or drops disposed next to one another, having a second polymer material, directly contacting the first material strands at contact points and being connected to one another causing the first material strands and the at least one of second material strands or drops to form the grid structure together; and producing the grid structure by: a) providing a depositing surface having a first direction and a second direction, b) providing the first and second polymer materials in a liquid state, c) extruding the first liquid polymer material by using at least one nozzle to form on the depositing surface a multiplicity of the first material strands disposed next to one another in the second direction, being spaced apart from one another and having a length respectively extending substantially in the first direction, d) extruding the second liquid polymer material by using at least one nozzle to form on the depositing surface a multiplicity of at least one of the second material strands or the drops being disposed next to one another in the first direction, being spaced apart from one another, contacting the first material strands at contact points and being connected to one another causing the first material strands and the at least one of second material strands or drops to form at least one portion of the band-shaped and one-piece grid structure together, e) transforming the at least one portion of the grid structure from a liquid or pasty and unstable state into a solidified and self-supporting state by: 1) solidifying the first polymer material, 2) solidifying the second polymer material, and 3) bringing about a material-bonded connection between the first and second polymer materials at the contact points; and f) removing the at least one portion of the solidified band-shaped and one-piece grid structure from the depositing surface.

15. The process according to claim 14, which further comprises moving the at least one nozzle and the depositing surface relative to one another in at least one of the first or second directions during the extrusion of the first and second polymer materials by using the at least one nozzle.

16. The process according to claim 14, which further comprises performing steps e1) to e3) simultaneously.

17. The process according to claim 14, which further comprises performing steps e1) and e2) or steps e2) and e3) simultaneously.

18. The process according to claim 14, which further comprises additionally providing a form-locking connection between the first material strands and the at least one of second material strands or drops at the contact points in at least one of step e1) or e2).

19. The process according to claim 14, which further comprises performing step c), then step e1), then process step d) and then step e2).

20. The process according to claim 14, which further comprises providing the depositing surface as a depositing band or a depositing roller having a circumferential direction extending in the first direction, the band or roller running around in its circumferential direction during the extrusion.

21. The process according to claim 14, wherein the first direction is substantially a lengthwise direction and the second direction is substantially a widthwise direction of the grid structure.

22. The process according to claim 20, which further comprises, while extruding the first polymer material, moving the at least one nozzle in the second direction and running the depositing band or the depositing roller around a plurality of times, causing the first material strands to form a helical structure together, with turns running in a circumferential direction of the depositing band or the depositing roller and progressing in the second direction.

23. The process according to claim 20, which further comprises depositing the first material strands onto the depositing band or the depositing roller together to form at least one helix having turns running around in a circumferential direction of the depositing band or the depositing roller and progressing in the second direction.

24. The process according to claim 20, which further comprises depositing the first material strands onto the depositing band or the depositing roller causing each first material strand to form a loop running around in a closed manner in a circumferential direction of the depositing band or the depositing roller and placing the loops individually next to one another in the second direction.

25. The process according to claim 14, which further comprises, while extruding the second polymer material, moving the at least one nozzle back and forth in an oscillating manner in the second direction and running the depositing band or the depositing roller around in a circumferential direction.

26. The process according to claim 14, which further comprises extruding the first material strands simultaneously over an intended width of the grid structure or extruding the first material strands simultaneously over only part of the intended width of the grid structure.

27. The process according to claim 20, which further comprises depositing the first and second material strands onto the depositing band or the depositing roller while forming the at least one portion of the grid structure and removing the first and second material strands from the depositing band or the depositing roller again before completion of one circulation of the depositing band or one revolution of the depositing roller.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

(1) The invention is further explained below on the basis of schematic drawings, in which:

(2) FIG. 1 shows a first embodiment of the process according to the invention for producing the clothing according to the invention,

(3) FIG. 2 shows a first embodiment of a partial aspect for the production of a grid structure or part thereof,

(4) FIG. 3 shows a second embodiment of a partial aspect for the production of a grid structure or part thereof,

(5) FIG. 4 shows a third embodiment of a partial aspect for the production of a grid structure or part thereof,

(6) FIG. 5 shows various refinements of the grid structure of the clothing according to the invention in plan view and

(7) FIG. 6 shows various refinements of the cross-sectional form of the grid structure of the clothing according to the invention.

DESCRIPTION OF THE INVENTION

(8) FIG. 1 shows a first embodiment of the process according to the invention for producing the clothing according to the invention.

(9) At a first processing station, shown in FIG. 1a, a grid structure 100 is produced by a process comprising the following steps. The working station shown in FIG. 1a for extruding the grid structure 100 is represented in plan view in FIG. 2.

(10) A depositing surface is provided, formed in the present case by a depositing band 1 and having an extent in a first direction and a second direction, in the present case the circumferential direction of the depositing band 1 extending in some portions in the first direction and the second, substantially in the widthwise direction CD of the grid structure to be produced. The depositing band 1 is led around a roller arrangement formed by two rollers 3, 4 that are spaced apart from one another.

(11) The first direction extends substantially in the lengthwise direction MD of the grid structure 100 to be produced.

(12) A first and a second polymer material are provided in a liquid or pasty state and can be extruded onto the depositing band 1 by means of an extrusion device 2 comprising a multiplicity of nozzles 2a, 2b.

(13) In the present case, the first and second polymer materials are the same polymer material, to be specific polyurethane.

(14) The extrusion device 2 may comprise here a number of first nozzles 2a, arranged next to one another in the second direction, and also a number of second nozzles 2b, arranged next to one another in the second direction.

(15) By means of the first nozzles 2a, the first polymer material is extruded in the liquid state onto the depositing band 1 in such a way that on the depositing surface 1 there are formed a multiplicity of first material strands 101, which are arranged next to one another in the second direction and are spaced apart from one another and in their length respectively extend substantially in the first direction MD.

(16) By means of the second nozzles 2b, the second polymer material is extruded in such a way that on the depositing surface 1 there are formed a multiplicity of second material strands 102, which are spaced apart from one another and contact the first material strands 101 at contact points and are connected to one another in such a way that the first material strands 101 and the second material strands 102 together form the grid structure 100.

(17) In the extrusion process, the two polymer materials are extruded by means of the nozzles 2a, 2b, the first and/or second nozzles 2a, 2b and the depositing surface 1 being moved in relation to one another in the first and/or second direction during the extrusion. This takes place by the depositing band 1 on the one hand running around in its circumferential direction during the extrusion and the first nozzles 2a not moving, whereby the first material strands 101 extending in the first direction MD are formed, and also by the depositing band 1 on the one hand running around in its circumferential direction during the extrusion and the second nozzles 2b moving back and forth in an oscillating manner in the second direction CD, whereby the second material strands 102 are created, extending in zigzag lines between the first material strands 101 but not crossing the first material strands 101.

(18) In the present case, the second material strands 102 extend in zigzag lines between the first material strands 101, the second material strands 102 not crossing the first material strands. In the present case, the first and second material strands 101, 102 are applied on the depositing band 1 at the same time.

(19) Furthermore, the first and second material strands 101, 102 are extruded at the same time over the intended width of the grid structure 100, the width of the grid structure 100 being less than the width of the basic structure 104 to be produced.

(20) The respective first material strand 101 is produced in the present case by at least one yarn being respectively extruded in the solid state together with the first polymer material in the liquid state through one of the nozzles. Formed as a result are first material strands 101, which respectively comprise at least one yarn, the at least one yarn of the respective material strand being at least partially enclosed by the first polymer material at least in some portions, in particular over its entire length. The at least one yarn may contain here at least one stretched monofilament or a multifilament or be provided thereby.

(21) After the extrusion process, the portion of the grid structure 100 that is still in a liquid or pasty, and therefore unstable, state is transformed by means of a solidifying device 5 into a solidified and self-supporting state by solidifying the first and second polymer materials and bringing about a material-bonded connection between the first and second polymer materials at the contact points. The solidifying of the first and second polymer materials may be brought about here by thermal exposure and/or by electromagnetic radiation and/or by chemical activation. The solidifying of the two polymer materials and their material-bonded connection at the contact points can take place here at the same time.

(22) After the portion of the grid structure 100 has solidified, it is removed from the depositing band 1 and fed to a roller 6 and wound up on it. By the process described here, the grid structure is produced as rolled stock.

(23) In the present case, the grid structure 100 has a width that is smaller than the width of the basic structure 104 to be produced. For this reason, in the processing steps that are shown in FIGS. 1b and 1c the grid structure 100 created and in the form of rolled stock is further processed to form the basic structure 104. For this purpose, the grid structure 100 is first made to the required length with a cutting unit 7 (see FIG. 1b) and subsequently the strips obtained from it are arranged next to one another in the widthwise direction of the basic structure 104 to be produced, along their longitudinal edges, and are connected to one another. This produces a flat-formed intermediate product made up of a number of strips of the grid structure 100, with a transverse edge 105 at one end and a transverse edge 106 at the other end. To form the basic structure 104, a seam connecting means 107 comprising the seam connecting elements 107a, 107b is arranged at the two transverse edges. To make the basic structure 104 continuous, the two transverse edges 105, 106 are brought together and connected to one another by means of the seam connecting means 107 107, as is shown in FIG. 1d.

(24) In the extrusion process and subsequent solidifying process shown in FIG. 3, a grid structure 100 is likewise created, the width of which is smaller than the width of the basic structure 104 to be produced. To produce the basic structure 104 with the desired width and length, directly following the creation of the grid structure 100 for this purpose the grid structure 100 is wound helically around two rollers 8, 9 spaced apart from one another, with turns that run around in the circumferential direction MD of the basic structure 104 and progress in the widthwise direction CD of the basic structure 104.

(25) To produce the grid structure 100 of FIG. 3, as in the case of the exemplary embodiment of FIG. 2, a first and a second polymer material are provided in a liquid or pasty state and extruded onto the depositing band 1 by means of an extrusion device 2 comprising a multiplicity of nozzles 2a, 2b.

(26) In the present case, the extrusion device 2 comprises a number of first nozzles 2a, arranged next to one another in the second direction CD, and also a number of second nozzles 2b, arranged next to one another in the first direction MD.

(27) By means of the first nozzles 2a, the first polymer material is extruded in the liquid state onto the depositing band 1 in such a way that on the depositing surface 1 there are formed a multiplicity of first material strands 101, which are arranged next to one another in the second direction and are spaced apart from one another and in their length respectively extend substantially in the first direction MD.

(28) By means of the second nozzles 2b, the second polymer material is extruded in such a way that on the depositing surface 1 there are formed a multiplicity of second material strands 102, which are spaced apart from one another in the first direction and contact and cross over the first material strands 101 at contact points and are connected to one another in such a way that the first material strands 101 and the second material strands 102 together form the grid structure 100.

(29) In the extrusion process, the two polymer materials are extruded by means of the nozzles 2a, 2b, the first and/or second nozzles 2a, 2b and the depositing surface 1 being moved in relation to one another in the first and/or second direction during the extrusion. This takes place by the depositing band 1 on the one hand running around in its circumferential direction during the extrusion and the first nozzles 2a not moving, whereby the first material strands 101 extending in the first direction MD are formed, and also by the depositing band 1 on the one hand running around in its circumferential direction during the extrusion and the second nozzles 2b moving from left to right in the second direction CD over the intended width of the grid structure 100 to be produced, whereby the second material strands 102 are created, running in CD and crossing the first material strands 101.

(30) Furthermore, the first and second material strands 101, 102 are extruded at the same time over the intended width of the grid structure 100, the width of the grid structure 100 being less than the width of the basic structure 104 to be produced.

(31) In the extrusion process and subsequent solidifying process shown in FIG. 4, a grid structure 100 is created, the width of which is equal to the width of the basic structure 104 to be produced.

(32) Furthermore, the first and second material strands 101, 102 are extruded at the same time over only part of the intended width of the grid structure 100.

(33) For this purpose, the grid structure 100 is extruded helically on a depositing surface formed by a depositing band 1 and subsequently solidified, until a grid structure 100 with the width and length of the basic structure 104 is created, before the grid structure 100 is removed from the depositing band 1. While the first polymer material is being extruded, the first nozzles 2a moves in the second direction CD, either only from left to right or only from right to left, i.e. without oscillation, while the depositing band 1 runs around a number of times in the circumferential direction MD, so that the first material strands 101 together form a helical structure, with turns that run in the circumferential direction of the depositing band 1 and progress in the second direction CD.

(34) FIG. 5 shows various embodiments of grid structures 100 according to the invention in plan view.

(35) The grid structure 100 of FIG. 5a is formed by first material strands 101 and second material drops 103, which are connected to and extend between the first material strands 101 but do not cross them.

(36) The grid structure 100 of FIG. 5b is formed by first material strands 101 and second material strands 102, which are connected to and extend in zigzag lines between the first material strands 101 but do not cross them.

(37) The grid structure 100 of FIG. 5c is formed by first material strands 101 and second material strands 102, which are connected to and extend between the first material strands 101, perpendicularly thereto, but do not cross them.

(38) The grid structure 100 of FIG. 5d is formed by first material strands 101 and second material strands 102, which are connected to and extend between the first material strands 101 in a circular manner but do not cross them.

(39) FIG. 6a shows refinements of the cross-sectional form of the first material strands 101 of the grid structure 100 of the clothing according to the invention. The first material strand 101, shown in FIG. 6a, has a circularly round cross-sectional form with a monofilament yarn 105, which is completely embedded in the first polymer material 106. The first material strand 101 shown in FIG. 6b has a rectangular cross-sectional form with a monofilament yarn 105, which is completely embedded in the first polymer material 106.