DE102010039364A1 - Wire for machine for manufacturing tissue web from fibrous material suspension, has laser source extending at region in transverse direction to machine direction, where extending regions are welded with one another - Google Patents

Abstract

The wire (1) has a fabric layer (L) with a trajectory-side surface (Lb) and/or a machine-side surface (Lm), and base bond thread in machine direction (R'). A web pattern is provided at remote winsock (RWS) ports, where the web pattern is closed by web seam (WN). Pads (KS) are coated with predetermined radiation absorbing material (M) with dye and a source of radiation. A laser source extends at a region (BV.i) in a transverse direction to a machine direction. The extending regions are welded with one another in parallel to the machine direction. Independent claims are also included for the following: (1) a method for manufacturing a wire (2) a machine comprising a temporary anchorage device (TAD) system.

Description

The invention relates to a sieve, in particular a sieve for a machine for producing a fibrous web, in particular a tissue web, comprising at least one fabric layer with a web-side surface and / or a machine-side surface having base bonds with machine-direction and cross-machine direction base weave threads, which has a weave pattern which repeats itself in repeats, and which are endlessly closed by means of at least one woven seam.

Furthermore, the invention relates to a method for producing the sieve according to the invention, in particular a sieve for a machine for producing a fibrous web, in particular a tissue web, from at least one pulp suspension.

The fibrous web can of course also be a paper, board or packaging paper web.

Such, usually by means of a woven seam endlessly closed screen is known from a variety of documents, such as the publications WO 00/12817 A1 and EP 1 736 595 A1 , It is particularly in the forming or wire section of a machine for producing a fibrous web of at least one pulp suspension used. In the forming process, the at least one pulp suspension is applied to the screen, which serves to dewater them and to form the at least single-layer fibrous web. In the dewatering process as few fibers and fillers as possible should be flushed out of the at least one Fasoffoffsuspension.

In the seam area of such a screen, commonly encountered problems are the lower machine direction tensile strength and the possible "slip-out" of the yarn ends of the machine direction base weaves, resulting in a further reduction in seam strength.

The woven seam usually contains areas in which the machine direction extending Grundbindungsfäden run parallel from both ends of the screen ("interlock"). This increases the machine direction tensile strength. However, this involves a noticeable reduction in permeability in the seam area. Thus, to keep the reduction in permeability in the seam area reasonably low, the seam area is made relatively large, with the areas of overlapping and machine-direction weave threads further apart. However, this is disadvantageous for the productivity in the production of the woven seam.

An improvement in the seam stability has already been achieved by an additional melting of the yarn ends of the machine direction extending Grundbindungsfäden to form a respective mushroom head ("Secure Seam"). Other types of weave can also be closed without interlock. In this case, the thread ends of the base binding threads extending in the machine direction are then blunt, approximately blunt or quasi-dull. Known here is also the welding of the butted thread ends of extending in the machine direction base binding threads to improve the seam strength.

For example, in the document WO 2009/032271 A2 discloses a method for welding a part of a screen, in particular the woven seam of a screen. It is provided that the screen is exposed to a laser energy absorbing material and that a laser source, in particular laser energy acts at discrete locations of the screen, thereby causing a partial melting and permanent welding of the screen at the discrete locations.

The material absorbing the laser energy is here applied flat to the seam area of the screen and the screen itself is exposed in its seam area to the full laser energy. Thus, an increased energy input is made in the sieve, causing it to melt excessively and ultimately shrink, so can experience a change in its mechanical and / or chemical properties.

And from the publication EP 1 359 251 A1 It is well known to fuse the longitudinal and transverse filaments of a sieve together at their points of intersection, for example by limited heating of the sieve to its melting temperature. The limited heating can take place selectively by means of laser, high-frequency and / or induction energy. Alternatively, however, the energy can also be applied in a planar manner if the crossing points are previously detected with an additive that promotes absorption of the energy, which concentrates the energy absorption despite the planar application to the points of intersection, so that only these heat to melting temperature and thus fuse together. The additive should be a light-absorbing dye, for example black color or a photoactive substance, when using a laser. The additive can also be added to the thread material already during the extrusion process.

It is therefore an object of the invention to improve a screen of the type mentioned in such a way that the aforementioned disadvantages of the prior art as far as possible, preferably completely eliminated. Furthermore, the particular effect of shrinkage of the screen causing energy input in the production of the woven seam of the screen should be significantly reduced and in the woven seam of the screen should also be produced during their production no structural changes. Another object of the invention is to provide a suitable method for the production of the woven seam of the screen.

The first object is achieved in a sieve of the type mentioned in the present invention that in the field of weaving a selection of, preferably all in the machine direction and transverse to the machine direction extending Grundbindungsfäden exclusively at their trained contact areas, in particular contact points after coating with a certain Radiation absorbing material, in particular a dye and when using at least one radiation source generating the particular radiation, in particular a laser source in at least one transversely to the machine direction extending region, preferably in a plurality of parallel or approximately parallel and transversely extending to the machine direction areas are welded together.

The object of the invention is completely solved in this way.

The inventive design of the sieve of the type mentioned provides the essential advantage of a significantly reduced energy input into the sieve, since the energy not, as known from the prior art, area, but only to the between the machine direction and transverse to the machine direction extending Basic binding threads trained and with a certain radiation absorbing material, in particular a dye coated contact areas, in particular contact points is introduced. As a result, no structural changes in the woven seam of the screen are caused and a possible shrinkage of the screen is also reduced, preferably even completely avoided.

In particular with regard to TAD and ATMOS sieves, the solution according to the invention is advantageous, since by them the permeability of the sieve changing, in particular worsening interlocks can be avoided. So far, the interlocks had to be distributed in a certain minimum range in order not to have a lasting negative influence on the permeability. If this distribution range was kept small, the fibrous web to be produced, in particular the tissue web, could not be sufficiently dewatered. With the solution according to the invention, in particular this previous disadvantage can be largely avoided, preferably completely.

In the context of the present invention, only a selection of base binding threads extending in the machine direction and transversely to the machine direction can be welded together exclusively at their formed contact areas, in particular contact points, in the area of the woven seam. Under production and material technical aspects, however, all the said basic binding threads are welded together in the manner described.

In a first preferred embodiment, the screen comprises at least one web-side first fabric layer and a machine-side second fabric layer, wherein at least the first fabric layer and the second fabric layer respective base bonds interconnected by binding yarns extending in a binder yarn direction with respective base weave yarns extending in the machine direction and cross machine direction wherein at least the first fabric layer and the second fabric layer each have a weave pattern which repeats in repeats, and wherein at least the first fabric layer and the second fabric layer are each endlessly closed by means of at least one woven seam.

The invention is therefore not limited to a single-layer sieve, as it is used for example in the production of a tissue web, but can also be transferred to a multi-layer sieve, as used for example in the production of a graphic fibrous web. Here, too, the aforementioned advantages arise.

The parallel or approximately parallel and transversely extending to the machine direction Verschweißungsbereiche preferably have a respective region width in the range of 1 to 5 cm, preferably from 1 to 4 cm on. And two adjacent parallel or approximately parallel and transversely extending to the machine direction Verschweißungsbereiche here have an unwelded range distance in the range of 0.5 to 3 cm, preferably from 1 to 2 cm on. In this way, the energy input into the seam region of the screen can be further reduced, without having to accept any disadvantages with regard to seam stability, seam stability or the like.

The woven seam of the screen may have a total seam width of ≦ 40 cm, preferably ≦ 25 cm, in particular ≦ 15 cm.

Furthermore, the parallel or approximately parallel and transversely extending to the machine direction Verschweißungsbereiche to the web-side surface or to the machine side surface of the screen out and preferably formed in a region in which the machine direction extending Grundbindungsfäden on the transverse to the machine direction extending Grundbindungsfäden float. As a result, the production of a rigid seam area can be dispensed with as far as possible.

Alternatively, the parallel or approximately parallel and transversely extending to the machine direction Verschweißungsbereiche are preferably arranged both to the web-side surface as well as to the machine-side surface of the screen and preferably formed in a region in which extending in the machine direction Grundbindungsfäden each across the transverse to Machine direction extending Grundbindungsfäden float. This also allows the energy input into the seam area of the screen to be reduced again, without having to accept any disadvantages with regard to seam stability, seam stability or the like.

The basic bonding threads which extend in the machine direction and are dull, approximately dull or virtually dull in the area of the woven seam are preferably after coating with the material absorbing a given radiation, in particular the dye and using at least one radiation source generating the particular radiation, in particular a laser source welded together. As a result, the ends of the base binding threads are also welded together, so that a further increased tensile strength is produced in the seam area of the screen.

The term "blunt" in the present description is understood to mean the spatial proximity of two ends of the staple binding threads. It is within the understanding of those skilled in the art that the two ends need not be arranged directly opposite one another, but can also be arranged adjacently in sections, that is, they may be arranged approximately dull or quasi-blunt against one another.

The base binding threads of the screen preferably consist at least partially of an organic polymer material and / or preferably have no or only a slight absorption of the particular radiation. Examples of such polymeric materials are: PET, PEN, PPS, PPEK or PA.

The second object is in a method for producing a screen, in particular a screen for a machine for producing a fibrous web, in particular a tissue web, comprising at least one fabric layer with a web-side surface and a machine-side surface, the base bonds in the machine direction and transverse to the machine direction itself Having extending base binding threads, which has a weave pattern, which repeats itself in rapport, and which is closed by at least one woven seam, inventively achieved in that in the region of the woven seam a selection of, preferably all in the machine direction and transverse to the machine direction extending base binding threads exclusively at their trained contact areas, in particular contact points after coating with a material which absorbs a certain radiation, in particular a dye and when using at least one of the specific radiation generating radiation source, in particular a laser source in at least one transversely to the machine direction extending region, preferably in a plurality of parallel or approximately parallel and transversely extending to the machine direction areas are welded together.

The object of the invention is again completely solved in this way and, moreover, the already mentioned inventive advantages.

As already stated, within the scope of the present invention in the area of the woven seam, only a selection of basic binding threads extending in the machine direction and transversely to the machine direction can be welded together exclusively at their formed contact areas, in particular contact points. Under production and material technical aspects, however, all the said basic binding threads are welded together in the manner described.

In a first preferred embodiment of the method according to the invention, the screen comprises at least one web-side first fabric layer and a machine-side second fabric layer, wherein at least the first fabric layer and the second fabric layer respective base bonds interconnected by binding yarns extending in a binder thread direction with respective machine direction and cross machine direction have at least the first fabric layer and the second fabric layer each have a weave pattern, which repeats itself in rapport, and wherein at least the first fabric layer and the second fabric layer are each closed by at least one woven seam endless.

Thus, the method according to the invention is not limited to the production of a single-layer sieve, as used for example in the production of a tissue web, but can also be transferred to the production of a multi-layer sieve, as used for example in the production of a graphic fibrous web. Here, too, the aforementioned advantages arise.

The parallel or nearly parallel and transversely extending to the machine direction Verschweißungsbereiche are preferably made with a respective region width in the range of 1 to 5 cm, preferably from 1 to 4 cm, and two adjacent parallel or approximately parallel and extending transversely to the machine direction welding regions are preferred with an unwelded range spacing in the range of 0.5 to 3 cm, preferably 1 to 2 cm. In this way, the energy input into the seam region of the screen can be further reduced, without having to accept any disadvantages with regard to seam stability, seam stability or the like.

The woven seam of the fabric produced by means of the method according to the invention may have a total seam width of ≦ 40 cm, preferably of ≦ 25 cm, in particular of ≦ 15 cm.

Furthermore, the parallel or approximately parallel and transversely extending to the machine direction Verschweißungsbereiche are preferably arranged to the web-side surface or to the machine side surface of the screen and preferably formed in a region in which extending in the machine direction Grundbindungsfäden on the transverse to the machine direction extending Basic binding threads float. As a result, the production of a rigid seam area can be dispensed with as far as possible.

Alternatively, the parallel or approximately parallel and transversely extending to the machine direction Verschweißungsbereiche are preferably arranged both to the web-side surface and to the machine side surface of the screen and preferably formed in a region in which extending in the machine direction Grundbindungsfäden each across the transverse to Machine direction extending Grundbindungsfäden float. This also allows the energy input into the seam area of the screen to be reduced again, without having to accept any disadvantages with regard to seam stability, seam stability or the like.

The machine direction extending and dull in the region of the woven seam, approximately dull or quasi-blunt adjacent Grundbindungsfaden are preferred after coating with a certain radiation absorbing material, in particular the dye and using at least one radiation source generating the particular radiation, in particular a laser source welded together. This will further increase tensile strength in the seam area of the screen without undergoing structural changes.

Furthermore, the material which absorbs a certain radiation is preferably provided with additives, for example Lumogen (BASF) or Clearweld (Gentex), carbon, black pigments and / or black ink, for example from a permanent marker. Also, it may contain water, at least one organic solvent and / or at least one surfactant such as a wetting agent or the like.

The particular radiation preferably has a wavelength in the range from 600 to 1400 nm, preferably from 808 nm, 940 nm, 980 nm or 1064 nm, since different radiation sources with these wavelengths are already available on the market. Thus, the investment and operating costs can be kept at an acceptable level.

And the radiation source generating the particular radiation preferably comprises a diode laser system or a neodymium YAG laser system having a power between 20 and 500 watts, preferably between 25 and 300 watts, in particular between 30 and 150 watts. Such radiation sources are available on the market, so that the investment and operating costs are positively influenced.

In order to effectively counteract possible but undesirable shrinkage of the screen, at least the area of the woven seam of the screen in which the welding will take place will be biased in both the machine direction and the cross-machine direction.

Moreover, at least the area of the woven seam of the wire in which the welding will take place will preferably also include the two areas extending beyond the area of the woven seam of the wire on both sides, in particular with a width of 0.01 to 0.1 m the material absorbing a certain radiation, in particular the dye coated. This ensures that even at all contact areas to be welded, in particular contact points sufficient that a certain radiation absorbent material, in particular the dye is present.

The coating is carried out with the material which absorbs a certain radiation, preferably in such a way that it only partially covers the base binding threads forming the screen.

Furthermore, the viscosity of the material which absorbs a certain radiation is preferably selected such that it penetrates into the interspaces between two contacting basic bonding threads.

With a view to a temporally optimized production of the screen, the material absorbing a certain radiation is preferably applied to the screen by means of common application methods such as spraying, rolling, brushing and the like.

Also, the coating with the material absorbing a certain radiation is preferably applied to the screen as a thin film having a coating thickness of ≤ 60 μm, preferably ≤ 30 μm, in particular ≤ 20 μm, so that the sieve pores are not clogged.

And the material applied to the screen as a coating and absorbing a certain radiation is preferably removed from the preferably accessible surface of the screen after being dried on the screen and before welding the base binding threads under the influence of mechanical cleaning and / or the aid of at least one solvent. This can be done, for example, by wiping with a fibrillated cloth soaked in a liquid that is a moderately to good solvent for the coating. The liquid may be, for example, a mixture of tetrahydrofuran (THF) (75%) and water (25%). The mechanical cleaning acts on all accessible surface areas of the screen. As an alternative to a cloth, it is also possible to use a roller with a fine-fiber surface, a brush, a brush roller or a combination of the means mentioned. Other cleaning methods not mentioned are not excluded.

Also, the material applied to the screen as a coating and absorbing a particular radiation is preferably removed from the preferably accessible surface of the screen such that in the region of the contact areas, particularly contact points, formed between the machine direction and cross-machine direction base binding threads in that the material which absorbs certain radiation, in particular the dye, remains as far as possible. Finally, this results in a woven seam which has the material absorbing the given radiation almost exclusively at the contact areas, in particular contact points of the base binding threads forming the screen.

Furthermore, the radiation source generating the particular radiation, in particular the laser source, is preferably moved flatly and preferably over the screen in the welding areas. As a result, the contact areas, in particular contact areas, which are coated with the material that absorbs a particular radiation, in particular the dye, are selectively heated, which ultimately leads to the welding of the contact areas, in particular contact points.

In addition, the radiation source generating the particular radiation, in particular the laser source with a radiation width of at least 1 cm, preferably of at least 2 cm, preferably flat and preferably in the Verschweißungsbereichen on the sieve moves.

The sieve according to the invention, in particular forming fabric is outstandingly suitable for use in a machine for producing a fibrous web, in particular tissue, paper, cardboard or packaging paper web, from at least one pulp suspension.

The machine for producing the fibrous web, in particular the tissue web, may in this case comprise at least one TAD system or one ATMOS system.

A well-known TAD system, as for example from the publication WO 2005/073461 A1 is known comprises at least one permeable sieve for forming the fibrous web and a sieve for transporting the fibrous web via a drying device, in particular a flow-through drying cylinder, the permeable sieve for forming the fibrous web usually a higher sieve speed than the sieve for transporting the fibrous web over having the drying device.

On the other hand, a known ATMOS system, as it is known from the document WO 2005/075736 A2 at least one permeable and structured sieve for transporting the fibrous web via a drying device, a permeable felt for dewatering between the fibrous web and the drying device and a permeable and tensioned belt for generating a dewatering pressure on the fibrous web in the region of the drying device.

Further features and advantages of the invention will become apparent from the following description of several preferred embodiments with reference to the drawings.

Show it

1 a schematic plan view of the seam region of a preferred embodiment of a sieve according to the invention;

2A to 2D several schematic sectional views of seam areas of preferred embodiments of a sieve according to the invention;

3 an enlarged plan view of a screen according to the invention, which has been coated with a certain radiation-absorbing material;

4 and 5 two enlarged plan views of screens according to the invention, each of which was selectively coated with a specific radiation absorbing material at the contact points and then cleaned;

6 an enlarged plan view of a selection of prepared for welding warp threads of a sieve according to the invention;

7 an enlarged plan view of a prepared for a welding and inventive sieve;

8th a schematic representation of a machine for producing a fibrous web, in particular a tissue web, which comprises at least one TAD system; and

9 a schematic representation of a machine for producing a fibrous web, in particular a tissue web, which comprises at least one ATMOS system.

The 1 shows a schematic plan view of the seam region NB of a preferred embodiment of a sieve according to the invention 1 , At the sieve 1 in particular, it may be a sieve 1 for a machine for producing a fibrous web, in particular a tissue, paper, cardboard or packaging paper web, from at least one pulp suspension act.

The sieve 1 comprises a fabric layer L with a web-side surface Lb and a machine-side surface Lm, the base weaves with machine direction R (arrow) extending base binding yarns B1.i, ie warp yarns, and transversely to the machine direction R * (double arrow) extending base binding yarns B2.i, So weft threads, has.

In the present illustration, the base binding threads B1.i extending in the machine direction R (arrow) extend from top to bottom, while the basic binding threads B2.i extending transversely to the machine direction R * (double arrow) extend from left to right.

The fabric layer L has in a known manner a weave pattern which is repeated in rapports, and is closed by means of at least one woven seam WN endless.

In the area of the woven seam WN are now according to the invention a selection of, preferably all in the machine direction R (arrow) extending Grundbindungsfäden B1.i and transverse to the machine direction R * (double arrow) extending Grundbindungsfäden B2.i exclusively at their trained contact areas KB, in particular Contact points KS after coating with a certain radiation absorbing material M, in particular a dye and using at least one radiation source generating the particular radiation, in particular a laser source in at least one transversely to the machine direction R * (double arrow) extending area BV.i, preferably in several parallel or approximately parallel and transverse to the machine direction R * (arrow) extending areas BV.i welded together (see. 2A ).

In the present embodiment, three parallel or approximately parallel and transverse to the machine direction R * (arrow) extending weld areas BV.1, BV.2 and BV.3 executed. They have a respective area width B in the range of 1 to 5 cm, preferably 1 to 4 cm, and two adjacent Verschweißungsbereiche BV.1 and BV.2, BV.2 and BV.3 have an unwelded range distance b in the range of 0th , 5 to 3 cm, preferably from 1 to 2 cm, on. The executed woven seam WN thus has a total seam width of ≦ 40 cm, preferably of ≦ 25 cm, in particular of ≦ 15 cm.

In a further embodiment, which is not explicitly shown but which is known to a person skilled in the art, the sieve can also comprise at least one web-side first fabric layer and a machine-side second fabric layer. In this case, at least the first fabric layer and the second fabric layer have respective base bonds interconnected by binding yarns extending in a binder yarn direction, with respective base weave yarns extending in the machine direction and transverse to the machine direction. Also have at least the first fabric layer and the second fabric layer in each case a weave pattern, which repeats itself in rapports. And at least the first fabric layer and the second fabric layer are each endlessly closed by at least one woven seam. The woven seam with these two fabric layers together with binding threads can be designed in the manner described, that is, at least one welded area can be provided.

The Grundbindungsfäden B1.i, B2.i at least partially made of an organic polymer material and / or have no or only a slight absorption of the particular radiation. Examples of such materials are: PET, PEN, PPS, PPEK or PA.

The 2A to 2D show several schematic sectional views of seam areas NB of preferred embodiments of a sieve according to the invention 1 , In the respective sectional illustration, a base binding thread B1.1 extending in the machine direction R (arrow) and a plurality of base binding threads B2.1 to B2.7 extending transversely to the machine direction R * (not illustrated) (cf. 2A ). The basic binding yarn B1.1 floats at least in places over the basic bonding yarns B2.1 to B2.7.

In the embodiment of the 2A are the parallel or approximately parallel and transverse to the machine direction R (arrow) extending weld areas BV.i to the machine side surface Lm of the screen 1 arranged. The illustrated welding area BV.i (B1.1 with B2.3 and B2.4) has an area width B in the range from 1 to 5 cm, preferably from 1 to 4 cm. The respective welding takes place in the manner already described.

Furthermore, in the embodiment of the 2 B the parallel or approximately parallel and transverse to the machine direction R (arrow) extending weld areas BV.i to the machine side surface Lm of the screen 1 arranged. The illustrated and dimensionally different welding region BV.i (B1.1 with B2.3, B1.1 with B2.6 and B2.7) have an area width B in the range from 1 to 5 cm, preferably from 1 to 4 cm , The respective welding takes place in the manner already described. The two adjacent welding regions BV.i have an unwelded range spacing b in the range from 0.5 to 3 cm, preferably from 1 to 2 cm.

In the embodiment of the 2C are the parallel or approximately parallel and transverse to the machine direction R (arrow) extending Verschweißungsbereiche BV.i turn to the machine side surface Lm of the screen 1 arranged. The illustrated welding area BV.i (B1.1 with B2.3 and B2.4, B1.1 with B2.5) has an area width B in the range from 1 to 5 cm, preferably from 1 to 4 cm. The respective welding takes place in the manner already described. In extension to that in the 2A In the present embodiment, the two ends of the basic binding thread B1.1 are also welded to the base binding thread B2.5, the two ends respectively running over the basic binding thread B2.5.

Also in the embodiment of the 2D are the parallel or approximately parallel and transverse to the machine direction R (arrow) extending Verschweißungsbereiche BV.i turn to the machine side surface Lm of the screen 1 arranged. The illustrated welding area BV.i (B1.1 with B2.3 and B2.4, B1.1 with B2.5 and B2.6) has an area width B in the range from 1 to 5 cm, preferably from 1 to 4 cm, on. The respective welding takes place in the manner already described. In change to that in the 2C In the embodiment shown, the two ends of the basic binding thread B1.1 are welded to the basic binding thread B2.5, but the two ends run between the basic binding threads B2.5 and B2.6.

In the two embodiments of the 2C and 2D the ends of the basic weave thread B1.1 are blunt in the area of the woven seam WN, approximately blunt or quasi-blunt. The term "dull" is understood to mean the spatial proximity of two ends of basic binding threads. It is within the understanding of those skilled in the art that the two ends need not be arranged directly opposite one another, but can also be arranged adjacently in sections, that is, they can be arranged approximately dull or quasi-blunt against one another.

In the 2A to 2D It can clearly be seen that in the region of the woven seam WN there is a selection of basic binding threads B1.i (B1.1) extending in the machine direction R (arrow) and base binding threads B2.i (B2.s) extending transversely to the machine direction (no representation) .2 to B2.7) exclusively at their trained contact areas KB, in particular contact points KS after coating with a certain radiation absorbing material M, in particular a dye and when using at least one radiation source generating the particular radiation, in particular a laser source in at least one transversely to the machine direction R * (double arrow) extending area BV.i, preferably in several parallel or approximately parallel and transverse to the machine direction R * (arrow) extending areas BV.i are welded together.

The welding areas BV.i can both machine side (representation) and / or rail side (see. 2A , dashed line) of the sieve 1 be arranged.

The 3 shows an enlarged plan view of a strainer according to the invention 1 which has been coated with a specific radiation absorbing material M.

The specific radiation-absorbing material M is preferably provided with additives, for example Lumogen (BASF) or Clearweld (Gentex), carbon, black pigments and / or black ink, for example from a permanent marker. The specific radiation absorbing material M may also contain water, at least one organic solvent and / or at least one surfactant such as a wetting agent or the like.

The material M which absorbs a certain amount of radiation is also applied to the wire by means of customary application methods such as spraying, rolling, brushing and the like.

And the coating is applied to the screen with the specific radiation absorbing material M as a thin film having a coating thickness of ≦ 60 μm, preferably ≦ 30 μm, especially ≦ 20 μm, so that the screen pores are not clogged.

For this sieve 1 The process according to the invention has been or is used for producing a sieve, in particular a sieve for a machine for producing a fibrous web, in particular a tissue web. In this case, in the region of the woven seam WN a selection of, preferably all in the machine direction R (arrow) extending Grundbindungsfäden B1.i and transverse to the machine direction R * (double arrow) extending Grundbindungsfaden B2.i exclusively at their trained contact areas KB, in particular contact points KS after coating with a certain radiation absorbing material M, in particular a dye and using at least one radiation source generating the particular radiation, in particular a laser source in at least one transversely to the machine direction R * (arrow) extending region BV.i, preferably in several parallel or approximately parallel and transverse to the machine direction R * (double arrow) extending areas BV.i welded together.

The 4 and 5 show two enlarged plan views of inventive sieves 1 , which were each selectively coated with a certain radiation absorbing material M at the contact areas KB, in particular contact points KS and then cleaned.

It can be seen that at least the region of the woven seam WN in which the welding will take place preferably also the two regions extending beyond the region of the woven seam WN on both sides, in particular with a region width of 0.01 to 0.1 m, with the one certain radiation-absorbing material M, in particular the dye have been coated.

The coating with the material M absorbing a certain radiation thus took place in such a way that it only partially covers the basic binding threads B1.i, B2.i forming the screen.

Also, the viscosity of the particular radiation absorbing material M has been chosen to penetrate into the interstices between two contacting base weave yarns B1.i, B2.i.

And that on the sieve 1 Coated and certain radiation absorbing material M became after drying on the screen 1 and before the welding of the base binding threads under the influence of mechanical cleaning and / or the aid of at least one solvent from the preferably accessible surface of the screen 1 away. This can be done, for example, by wiping with a fibrillated cloth soaked in a liquid that is a moderately to good solvent for the coating. The liquid may be, for example, a mixture of tetrahydrofuran (THF) (75%) and water (25%). The mechanical cleaning acts on all accessible surface areas of the screen. As an alternative to a cloth, it is also possible to use a roller having a fine-fiber surface, a brush, a brush roller or a combination of the means mentioned. Other cleaning methods not mentioned are not excluded.

This was also on the sieve 1 coated as a coating and a certain radiation absorbing material M from the preferably accessible surface of the screen 1 removed such that in the region of the contact areas KB, in particular contact points KS, which are formed between the machine direction R (arrow) extending Grundbindungsfäden B1.i and transverse to the machine direction R * (arrow) extending Grundbindungsfäden B2.i, the certain radiation-absorbing material M, in particular the dye remains as far as possible. The contact areas KB, in particular contact points KS of two basic binding threads B1.i, B2.i and their immediate surroundings remain unaffected, however, since they are are inaccessible for mechanical cleaning. Ultimately, this gives a woven seam WN, which contains the material M absorbing the specific radiation almost exclusively at the contact areas KB, in particular contact points KS of the sieve 1 having forming base binding threads B1.i, B2.i.

The 6 shows an enlarged plan view of a selection of prepared for welding warp threads B1.i a sieve according to the invention 1 ,

The welding is achieved by the fact that the radiation source generating the particular radiation, in particular the laser source, is flat over the wire and preferably in the welding areas BV.i. 1 will be moved and that selectively with the a certain radiation absorbing material M, in particular the dye coated contact areas KB, in particular contact points KS will be heated, which will ultimately lead to the welding of the contact areas KB, in particular contact points KS.

The radiation source generating the particular radiation, in particular the laser source, is provided with a radiation width of at least 1 cm, preferably of at least 2 cm, flat and preferably in the welding regions BV.i over the screen 1 wherein the particular radiation will preferably have a wavelength in the range of 600 to 1400 nm, preferably 808 nm, 940 nm, 980 nm or 1064 nm.

And the radiation source generating the particular radiation will comprise a diode laser system or neodymium YAG laser system having a power between 20 and 500 watts, preferably between 25 and 300 watts, in particular between 30 and 150 watts.

With regard to the process technology, at least the area of the woven seam WN in which the welding will take place will be prestressed in the machine direction R (arrow) as well as transversely to the machine direction R * (arrow) in a known manner.

And the 7 finally shows an enlarged plan view of a prepared for welding and inventive sieve 1 ,

It can be clearly seen that in the region of the woven seam WN a selection of, preferably all base binding threads B1.i extending in the machine direction R (arrow) and transverse to the machine direction R * (double arrow) extending basic binding threads B2.i only at their trained contact areas KB, in particular contact points KS after unilateral coating with a certain radiation absorbing material M, in particular a dye and using at least one radiation source generating the particular radiation, in particular a laser source in at least one transverse to the machine direction R * (double arrow) extending area BV. i, preferably in a plurality of parallel or approximately parallel and transverse to the machine direction R * (arrow) extending areas BV.i are welded together.

That in the 1 to 7 At least partially illustrated inventive sieve 1 including manufacturing method is particularly suitable for use in a machine for producing a fibrous web, in particular a tissue web.

The 8th shows a schematic representation of a machine 100 for producing a fibrous web 101 , in particular a tissue web, the at least one TAD system 102 includes.

A pulp suspension is by means of a known headbox 103 between two sieves 104 . 105 introduced and on the sieve 104 led and further drained. The fibrous web to be formed 101 then becomes each other's sieve 104 at one with a sieve 107 provided vacuum shoe 106 passed and thereby from the sieve 107 accepted. The sieve 107 then passes the fibrous web to be formed 101 to another sieve 108 , which is the fibrous web to be formed 101 then via a known drying device 109 , in particular a flow-through drying cylinder leads. After this tour of the drying device 109 becomes the fibrous web to be formed 101 taken from the same and by means of several other sieves 110 . 111 to a winding machine 112 guided and on this to a winding roll 113 wound. Generally, that is the sieve 107 for the formation of the fibrous web 101 usually a higher wire speed than the wire 108 for transporting the fibrous web to be formed 101 having.

With regard to further properties of this TAD system 102 is on the already mentioned document WO 2005/073461 A1 The content of which is hereby made the subject of the present description.

The 9 shows a schematic representation of a machine 100 for producing a fibrous web 101 , in particular a tissue web, the at least one ATMOS system 114 includes.

A pulp suspension is made by means of a permeable and structured sieve 115 via a drying device 116 guided. Continue a permeable felt 117 for dewatering between the fibrous web to be formed 101 and the drying device 116 and a permeable and tense band 118 for generating a dewatering pressure on the fibrous web to be formed 101 in the area of the drying device 116 used.

With regard to further properties of this ATMOS system 114 is on the already mentioned document WO 2005/075736 A2 The content of which is hereby made the subject of the present description.

That in the 1 to 7 At least partially illustrated inventive sieve 1 is particularly suitable for use in a machine for producing a fibrous web, in particular a tissue, paper, cardboard or packaging paper web, from at least one pulp suspension.

In summary, it should be noted that a sieve of the type mentioned above is improved by the invention so that the aforementioned disadvantages of the prior art as far as possible, preferably completely eliminated. Furthermore, the particular effect of shrinkage of the sieve causing energy input in the production of the woven seam of the screen is significantly reduced and in the woven seam of the sieve are also caused during their production no structural changes.

LIST OF REFERENCE NUMBERS

1

scree

100

Machine for producing a fibrous web

101

Fibrous web, in particular tissue web

102

TAD system

103

headbox

104

scree

105

scree

106

vacuum shoe

107

scree

108

scree

109

drying device

110

scree

111

scree

112

winder

113

reel

114

ATMOS system

115

scree

116

drying device

117

felt

118

tape

B

area width

b

range distance

B1.i

Basic binding thread, warp thread

B1.1

Basic binding thread, warp thread

B2.i

Basic binding thread, weft

B2.1 to B2.7

Basic binding thread, weft

BV.i

welding region

BV.1

welding region

BV.2

welding region

BV.3

welding region

KB

contact area

KS

contact point

L

fabric layer

lb

Track side surface

Lm

Machine-side surface

M

material

NB

seam area

R

Machine direction (arrow)

R *

Transverse to the machine direction (double arrow)

WN

woven seam

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 00/12817 A1 [0004]
• EP 1736595 A1 [0004]
• WO 2009/032271 A2 [0008]
• EP 1359251 A1 [0010]
• WO 2005/073461 A1 [0051, 0100]
• WO 2005/075736 A2 [0052, 0103]

Claims (30)

Scree ( 1 ), in particular a sieve for a machine ( 100 ) for producing a fibrous web ( 101 ), in particular a tissue web of at least one pulp suspension, comprising at least one fabric layer (L) with a web-side surface (Lb) and / or a machine-side surface (Lm), the base weaves in the machine direction (R) and transversely to the machine direction (R *) comprising base weave threads (B1.i, B2.i) which has a weave pattern which repeats in repeats and which is endlessly closed by means of at least one weave seam (WN), characterized in that in the region of the weave seam (WN) a selection of, preferably all in the machine direction (R) and transverse to the machine direction (R *) extending Grundbindungsfäden (B1.i, B2.i) exclusively at their formed contact areas (KB), in particular contact points (KS) after coating with a certain radiation-absorbing material (M), in particular a dye and when using at least one radiation source generating the particular radiation, esp a laser source in at least one transverse to the machine direction (R *) extending region (BV.i), preferably in several parallel or approximately parallel and transversely to the machine direction (R *) extending regions (BV.i) are welded together. Scree ( 1 ) according to claim 1, characterized in that it comprises at least one web-side first fabric layer and a machine-side second fabric layer, wherein at least the first fabric layer and the second fabric layer respective base bonds interconnected by binding yarns extending in a binder yarn direction with respective ones in the machine direction and transverse to the machine direction have at least the first fabric layer and the second fabric layer each have a weave pattern, which repeats in repeats, and wherein at least the first fabric layer and the second fabric layer are each closed by at least one woven seam endless. Scree ( 1 ) according to claim 1 or 2, characterized in that the parallel or approximately parallel and transverse to the machine direction (R *) extending Verschweißungsbereiche (BV.i; BV.1 to BV.3) a respective area width (B) in the range of 1 to 5 cm, preferably from 1 to 4 cm, and that two adjacent parallel or approximately parallel and transversely to the machine direction (R *) extending weld areas (BV.1 and BV.2, BV.2 and BV.3) an unwelded Range distance (b) in the range of 0.5 to 3 cm, preferably from 1 to 2 cm. Scree ( 1 ) according to claim 1, 2 or 3, characterized in that the parallel or approximately parallel and transverse to the machine direction (R *) extending Verschweißungsbereiche (BV.i) to the web-side surface (Lb) or to the machine-side surface (Lm) of Sieves ( 1 ) and are preferably formed in an area in which the base binding threads (B1.i) extending in the machine direction (R) float over the base binding threads (B2.i) extending transversely to the machine direction (R *). Scree ( 1 ) according to claim 1 or 2, characterized in that the parallel or approximately parallel and transverse to the machine direction (R *) extending Verschweißungsbereiche (BV.i) both to the web-side surface (Lb) and to the machine-side surface (Lm) of the Sieves ( 1 ) and are preferably formed in a region in which the base binding threads (B1.i) extending in the machine direction (R) each float over the base binding threads (B2.i) extending transversely to the machine direction (R *). Scree ( 1 ) according to one of the preceding claims, characterized in that in the machine direction (R) extending and in the region of the woven seam (WN) dull, approximately dull or quasi-blunt adjacent Grundbindungsfäden (B1.i) after coating with a certain radiation absorbent material (M), in particular the dye and when using at least one radiation source generating the particular radiation, in particular a laser source are welded together. Scree ( 1 ) according to one of the preceding claims, characterized in that the base binding threads (B1.i, B2.i) at least partially consist of an organic polymer material and / or have no or only a slight absorption of the particular radiation. Method for producing a sieve ( 1 ), in particular a sieve for a machine ( 100 ) for producing a fibrous web ( 101 ), in particular a tissue web of at least one pulp suspension, comprising at least one fabric layer (L) with a web-side surface (Lb) and / or a machine-side surface (Lm), the basic bonds with in Machine direction (R) and transverse to the machine direction (R *) extending base binding threads (B1.i, B2.i), which has a weave pattern which repeats itself in rapport, and which is closed endlessly by means of at least one woven seam (WN), characterized in that in the region of the woven seam (WN) a selection of, preferably all in the machine direction (R) and transverse to the machine direction (R *) extending base binding threads (B1.i, B2.i) exclusively at their trained contact areas (KB ), in particular contact points (KS) after coating with a certain radiation absorbing material (M), in particular a dye and using at least one radiation source generating the particular radiation, in particular a laser source in at least one transversely to the machine direction (R *) extending region BV.i), preferably in several parallel or approximately parallel and transversely to the machine direction (R *) extending Ber oak (BV.i) are welded together. A method according to claim 8, characterized in that it comprises at least one web-side first fabric layer and a machine-side second fabric layer, wherein at least the first fabric layer and the second fabric layer respective bonded together by binding threads extending in a binding yarn base bonds with respective in the machine direction and transverse to the machine direction have at least the first fabric layer and the second fabric layer each have a weave pattern, which repeats itself in rapport, and wherein at least the first fabric layer and the second fabric layer are each closed by at least one woven seam endless. A method according to claim 8 or 9, characterized in that the parallel or approximately parallel and transverse to the machine direction (R *) extending Verschweißungsbereiche (BV.i; BV.1 to BV.3) with a respective area width (B) in the range of 1 to 5 cm, preferably 1 to 4 cm, and that two adjacent parallel or approximately parallel and transversely to the machine direction (R *) extending Verschweißungsbereiche (BV.1 and BV.2, BV.2 and BV.3) with an unwelded area distance (b) in the range of 0.5 to 3 cm, preferably 1 to 2 cm, are produced. A method according to claim 8, 9 or 10, characterized in that the parallel or approximately parallel and transversely to the machine direction (R *) extending Verschweißungsbereiche (BV.i) to the web-side surface (Lb) or to the machine-side surface of the screen ( 1 ) and are preferably formed in a region in which the base binding threads (B1.i) extending in the machine direction (R) float over the base binding threads (B2.i) extending transversely to the machine direction (R *). A method according to claim 8, 9 or 10, characterized in that the parallel or approximately parallel and transverse to the machine direction R *) extending Verschweißungsbereiche (BV.i) both to the web-side (Lb) surface and to the machine-side surface (Lm) of the sieve ( 1 ) and are preferably formed in a region in which the base binding threads (B1.i) extending in the machine direction (R) float in each case over the base binding threads (B2.i) extending transversely to the machine direction (R *). Method according to one of claims 8 to 12, characterized in that in the machine direction (R) extending and in the region of the woven seam (WN) of the sieve (WN) 1 ) blunt, approximately blunt or quasi-blunt abutting basic binding threads (B1.i) after coating with the specific radiation absorbing material (M), in particular the dye and when using at least one radiation source generating the particular radiation, in particular a laser source are welded together. Method according to one of claims 8 to 13, characterized in that the radiation absorbing material (M) with additives such as Lumogen (BASF) or Clearweld (Gentex), carbon, black pigments and / or black ink, for example of a permanent -Marker, is provided. Method according to one of claims 8 to 14, characterized in that the material which absorbs a certain radiation (M) contains water, at least one organic solvent and / or at least one surface-active substance, such as a wetting agent or the like. Method according to one of claims 8 to 15, characterized in that the particular radiation has a wavelength in the range of 600 to 1400 nm, preferably of 808 nm, 940 nm, 980 nm or 1064 nm. Method according to one of claims 8 to 16, characterized in that the radiation source generating the particular radiation is a diode laser system or a neodymium-YAG laser system with a power between 20 and 500 watts, preferably between 25 and 300 watts, in particular between 30 and 150 watts , includes. Method according to one of claims 8 to 17, characterized in that at least the region of the woven seam (WN) of the sieve (WN) 1 ), in which the weld will take place, is biased in both the machine direction (R) and the cross-machine direction (R *). Method according to one of claims 8 to 18, characterized in that at least the region of the woven seam (WN) of the sieve (WN) 1 ), in which the welding will take place, preferably also the two on both sides over the area of the woven seam (WN) of the sieve ( 1 ), in particular with an area width of 0.01 to 0.1 m, with which a certain radiation absorbing material (M), in particular the dye is or become. Method according to one of Claims 8 to 19, characterized in that the coating with the material (M) absorbing a certain radiation is carried out in such a way that it seals the sieve ( 1 ) forming the basic binding thread (B1.i, B2.i) is only partially covered. A method according to any one of claims 8 to 20, characterized in that the viscosity of the material (M) absorbing a given radiation is chosen such that it penetrates into the interstices between two contacting basic bonding threads (B1.i, B2.i). Method according to one of claims 8 to 21, characterized in that the material absorbing a certain radiation (M) by means of common application methods such as spraying, rolling, brushing and the like on the screen ( 1 ) is applied. Method according to one of claims 8 to 22, characterized in that the coating with the specific radiation absorbing material (M) as a thin film having a coating thickness of ≤ 60 microns, preferably ≤ 30 microns, in particular ≤ 20 microns on the sieve ( 1 ) is applied. Method according to one of claims 8 to 23, characterized in that on the sieve ( 1 ) applied as a coating and a certain radiation absorbing material (M) after drying on the screen ( 1 ) and before the welding of the base binding threads (B1.i, B2.i) under the influence of mechanical cleaning and / or the aid of at least one solvent from the preferably accessible surface of the screen ( 1 ) Will get removed. A method according to claim 24, characterized in that on the sieve ( 1 ) applied as a coating and a certain radiation absorbing material (M) from the preferably accessible surface of the sieve ( 1 ) is removed such that in the region of the contact regions (KB), in particular contact points (KS), between the machine direction (R) and transverse to the machine direction (R *) extending base binding threads (B1.i, B2.i) is formed are that the particular radiation absorbing material (M), in particular the dye remains as far as possible. Method according to one of claims 8 to 25, characterized in that the radiation source generating the particular radiation, in particular the laser source surface and preferably in the Verschweißungsbereichen on the sieve ( 1 ) is moved and that selectively with the a certain radiation absorbing material (M), in particular the dye coated contact areas (KB), in particular contact point (KS) are heated, which ultimately for welding the contact areas (KB), in particular contact points (KS) leads. Method according to one of claims 8 to 26, characterized in that the radiation source generating the particular radiation, in particular the laser source having a radiation width of at least 1 cm, preferably of at least 2 cm, areally and preferably in the Verschweißungsbereichen on the screen ( 1 ) is moved. Machine ( 100 ) for producing a fibrous web ( 101 ), in particular a tissue web of at least one pulp suspension, characterized in that it comprises at least one sieve ( 1 ) according to any one of claims 1 to 7. Machine ( 100 ) according to claim 28, characterized in that it comprises at least one TAD system ( 102 ) comprising at least one permeable sieve ( 104 . 107 ) to form the fibrous web ( 101 ) and a sieve ( 105 ) for transporting the fibrous web ( 101 ) via a drying device ( 109 ), in particular a through-flow drying cylinder, wherein the permeable sieve ( 107 ) to form the fibrous web ( 101 ) usually a higher wire speed than the wire ( 108 ) for transporting the fibrous web ( 101 ) via the drying device ( 109 ). Machine ( 100 ) according to claim 28, characterized in that it comprises at least one ATMOS system ( 114 ) comprising at least one permeable and structured sieve ( 115 ) for transporting the fibrous web ( 101 ) via a drying device ( 116 ), a permeable felt ( 117 ) for dewatering between the fibrous web ( 101 ) and the drying device ( 116 ) and a permeable and tensioned band ( 118 ) for generating a dewatering pressure on the fibrous web ( 101 ) in the area of the drying device ( 116 ).

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