KR100290458B1 - Screening device, such as a screen cylinder, and method of manufacture of the screening device - Google Patents

Abstract

The present invention relates to screening devices such as screen cylinders for screening, penetrating, fractionating or classifying pulp suspensions and the like in the pulp and paper manufacturing industry. The screening device comprises a plurality of filter wires 10 arranged at small intervals parallel to each other, and at least one longitudinal support element 12 supporting the filter wires on top. According to the present invention each support element 12 has a plurality of support slots 17 formed through an upstream side surface, which slots are shaped to accommodate the downstream section 14 of the filter wire 10. . The filter wire 10 is locally fixed to the material 19, 36 in the slot 17 and fixed to the slot in the support element.

Description

Screening devices, such as screen cylinders, and methods for manufacturing the screening devices {SCREENING DEVICE, SUCH AS A SCREEN CYLINDER, AND METHOD OF MANUFACTURE OF THE SCREENING DEVICE}

In known screening devices of this type, the support elements forming the support for the filter wire are mainly rectangular or circular in cross section and most typically are arranged perpendicular to the filter wire.

Generally, the filter wire is fixed to the support bar by a welding process resulting in many disadvantages such as modified torsion, thermal stress and burrs. Heat caused by welding often causes twisting of the wires and a change in the screening opening width between adjacent wires. Therefore, it is difficult to obtain a completely uniform screening opening, which means that the efficiency of the screen is poor. Today, when the desired width of the screening opening is as small as 0.1 mm, only minimal torsion can be tolerated.

Thermal stress and burrs can also cause failures in operation due to loading on the screening device in the user's process. Such loading may be in either form of constant load or cycle loading that causes failure by fatigue.

The burr may also trap the fibers in the suspension, resulting in gradual blockage of the screen or filter, or the formation of so-called 'strings' which are very harmful in the user's process.

In U.S. Patent Nos. 5,090,721 and 5,090,360, it has also been proposed to connect filter wires of constant 'key' cross section to grooves in the support bar, having the same 'key' shape. By bending the support bar into the ring, the filter wire is fixed in position. Thus, this design requires the manufacture of a large number of recesses, which are relatively complex and consequently expensive. Moreover, this design may only be suitable for circular screens where the flow is from inside to outside of the circular screen.

In another known screening device the filter wire is fixed by looping the wire around the support bar. This screen configuration is robust, but the roofing area around the support bar locally closes the opening to reduce the throughput of the screen. In addition, the looped areas tend to have cavities and non-uniform spots that abut suspensions that can result in fiber sticking.

The above difficulties tend to lead to poor screening or mechanical defects or high manufacturing costs, and consequently the object of the present invention is to provide an improved screening apparatus and an improved method of manufacturing such apparatus, minimizing the above mentioned disadvantages. .

The present invention relates to a screening device and a method of manufacturing the same as cited in the preamble of the attached independent claim. The present invention relates to screening devices such as screen cylinders or curved or flat screening elements that screen, filter, fractionate and classify pulp suspensions or other similar suspensions in the pulp and paper manufacturing industry. More specifically, the present invention relates to a screening device of the type comprising a plurality of filter wires arranged at small intervals parallel to each other, the plurality of filter wires forming a screening surface that abuts the pulp suspension to be screened and the adjacent wires are A screening opening may be formed therebetween so that the receptacle of the pulp suspension can flow through the opening. EP 0 316 570 discloses such a screening device in which the filter wire is fixed in the transversely extending slot in the rigid support element, the support ring or the support bar on the downstream side of the wire by welding. The screening device may have various forms, such as flat, curved, cylindrical or conical.

1 is a schematic top side view of a filter wire disposed on a support element according to a preferred embodiment of the present invention.

2 is a longitudinal sectional view of a portion of the support element in FIG. 1 with three filter wires supported thereon;

3 shows schematically a top side view of a filter wire when placed on a support element according to another embodiment of the invention;

4 a filter wire according to FIG. 3 arranged on a support element;

5 a filter wire according to FIG. 3 secured to a support element;

6 is the element of FIG. 5 inverted;

7a-7d schematically show an assembly step of a filter wire connected to a support bar in a tooled assembly machine which deforms the base portion of the filter wire;

It is therefore an object of the present invention to also provide a screening device which is easily manufactured and assembled without the thermal twisting of the filter wire.

It is also an object of the present invention to provide an improved, robust screening device having precise and constant screening openings, such as screening slots.

It is a further object of the present invention to provide an improved method of manufacturing the screening apparatus such that uniform screening openings with good tolerances and the like are provided so that slots with very small widths can be produced.

It is a further object of the present invention to provide an improved screening device with minimal burrs or other protruding elements that accumulate fibers on the upstream side surface of the support rod.

These objects are achieved with a screening device and method as described in the features of the independent claims 1 and 13.

A preferred screening device according to the present invention is provided comprising a plurality of filter wires supported by at least one longitudinal support element, wherein the plurality of support slots or grooves are formed through an upstream side surface of the support element and the filter wires It is fixed in the slot. The longitudinal direction of the support slots or grooves forms an angle, typically 90 ° with respect to the longitudinal axis of the support element, and is shaped to accommodate the downstream cross section of the filter wire. The slot is typically cut perpendicular to the support element, for example radially on the longitudinal axis of the support element, but if the wire is supported in an angular position it may be cut at an angle between 10 ° and 90 ° at the support element. have. After assembling the wire to the support slot in the support element, the filter wire is fixed to the slot or the groove by a downstream cross section of the filter wire or by a recess restriction region of the support element or a local deformation of the material in the slot.

In the screening apparatus, according to a preferred embodiment of the present invention, the at least one support element has a cavity defined by the side surface on the upstream side support slot and on the downstream side. This cavity can be formed by a variety of techniques, including drawing, extrusion, rolling or machining. The plurality of support slots are preferably through openings that reach from the upstream side surface of the support element to the cavity. During assembly of the downstream cross section of the filter wire, a base portion which projects into the cavity through the slot and preferably intersects with the cavity is inserted into the support slot in the support element. The upstream side surface of the support element in contact with the suspension flow preferably has a circular (convex) shape to reduce flow resistance.

Slots, which may be formed by machining, stamping, flame erosion or lasers, etc., form an angle that intersects the axis of the support element. This angle is typically 90 ° but can be in the range of 1 ° -90 °. The spacing and depth of the support slots also determine the position of the filter wire inserted therein and thus the width of the screening opening.

The filter wire deforms the base part of the downstream section of the wire and is fixed to the support element, so that the deformation prevents the base part from entering the slot again and withdrawing the wire. The filter wire material encapsulated in the support element cavity is preferably deformed using mechanical force. The deformed material forms a mechanical joint, which is burr free and fatigue resistant with good properties. The shape of the deformed material determines the final performance of the joint withstanding the forces generated by the infiltration process. The shape of the joint also determines the final fatigue resistance of the joined material.

The shape of the deformation can be determined by the tool used to form the joint. The tool may have a flat, concave, convex, conical or dome shape to allow material to flow in the direction that is optimally determined for the joint. The joint may be completed alone or multiplely in parallel filter wires to speed up the manufacture of the screening device or to ensure stability during processing. Other tools can be used at the same time to support adjacent support slots in the support element such that maximum force is applied to the joint to be formed, resulting in no distortion of the adjacent support slots or filter wires. Such support may be provided by an inserted filter wire that is held in position by a clamping force.

Transverse slots in adjacent, preferably parallel, support elements should be aligned to accommodate straight filter wire lengths. In general, the filter wire material must be upright before being connected to the assembly and support slots.

According to another embodiment of the invention, the filter wire is inserted into a support slot or groove, and then the support element material in the slot or groove area is locally pressed to squeeze a portion of the slot wall against the filter wire portion in the slot or groove. Deformation (in the point direction or in the cross section). Deformation of the slot or groove occurs at a location selected to prevent the filter wire from being drawn out of the slot or groove. The slot or recess is preferably deformed by mechanical force, such as pressing or stamping in the direction of the upstream side surface of the support element. This mechanical force is applied to provide local deformation of the support element material around the slot or groove without causing deformation or twist of the entire support element and without twisting the filter wire. The downstream section of the filter wire inserted in the slot or groove may provide space for the deformed material and provide reentrant features to reinforce the joint. The deformation of the side surface is then suitable for locking the forming wire in the slot or groove. If the slot is formed as a through opening, both the base portion of the wire and the slot wall material can be modified to provide a joint.

The support element and filter wire are preferably supported during the mechanical deformation process to prevent undesirable assembly changes.

According to a preferred embodiment of the present invention, a new method of manufacturing the screening device comprises the following steps:

On the upstream side surface of the at least one support element by machining, cutting or another similar manner, forming a plurality of support slots that are angled with respect to the axis of the support element and adapted to receive the downstream section of the filter wire Steps,

Inserting one of the plurality of filter wires into one of the plurality of support slots, and

Locally modifying the material in the downstream section of the filter wire or in the slot limit area of the support element to secure the filter wire inserted in the support slot to the support element.

In the screen cylinder according to the present invention the support element is preferably a circular ring having a plurality of filter wires parallel to the axis of the cylinder and fixed on top. The filter wire can be fixed around the inside or outside of the ring. Preferably at least two rings are present in each screen cylinder, but may be more. The ring may simultaneously form a support ring that stabilizes the screen cylinder itself.

Preferably, the plurality of support slots formed on the support element by machining or in any other suitable manner is mainly perpendicular to the longitudinal axis of the at least one support element such that the filter wire connected to the support element is perpendicular to the element. Do. However, it is possible to provide an inclined support slot on the support element if desired to be supported at an angle.

The cross section of the filter wire preferably has a wider cross section that abuts the suspension to be screened and a narrower cross section that protrudes into a slot in the support element (support bar) to form a relief channel between adjacent filter wires through which the suspension is to pass. The width of the cross section in contact with the suspension is typically 2 to 8 mm, preferably 2.8 to 5 mm.

The support element according to the invention may consist of a bar having a U-, L- or V-shaped or other similar shaped cross section. The bar thus has a bent or inclined first (center) part to which the filter wire is fixed and a second part forming an additional support body. The convex outer side surface of the curved or inclined first portion of the bar defines an upstream side surface that abuts the flow of the suspension flowing through the screening device.

Typically, the support element according to a preferred embodiment of the present invention consists of a partially rigid support bar whose cross section is preferably slightly thin and long, with one end of the cross section being convex or convex and the opposite end having a cavity formed therein. Have The support bar is disposed in the screening device such that the circular or convex side is arranged to abut the flow entering through the screening openings formed between adjacent wires to provide optimum flow along the outer surface of the support bar. The cavity in the support bar is thus provided on the downstream side of the support element. The total height of the support bars is typically in the range of 10 to 25 mm, preferably 13 to 20 mm, the width of which is in the range of 5 to 15 mm, preferably approximately 6 to 8 mm. This cavity typically projects into the downstream side of the support bar by approximately 5 to 15 mm, preferably 6 to 10 mm. The wall thickness of the support bar on the side of the cavity may be at least 1 mm, typically approximately 1-3 mm.

The support slot is formed in the downstream side of the convex or circular support bar. The support slots typically have a depth h ₂ corresponding to 0.25 to 0.50 of the total height H of the support elements. The support slot may thus have a depth of 0.3 to 0.9 h ₂ of filter wire height. The slot typically reaches a depth of 1 to 3 mm into the cavity.

A wire having a height of approximately 5 to 15 mm, preferably approximately 7 to 12 mm is supported by a support bar. The cross section of the wire has a broad top (eg upstream) section of the funnel shape, preferably from about 3-5 mm to about 1.5-upstream in the upper 1/3-1/2 part of the total height of the wire. With a width reduced to 3 mm. The wire is inserted into the support slot, which preferably has a funnel shaped top section corresponding to the shape of the wire. The depth of the support slot and / or the funnel-shaped top of the slot and the wire determines the depth at which the wire can be inserted into the slot.

The base portion of the downstream end of the wire reaches a cavity in the support bar according to a preferred embodiment of the present invention. The wire deforms at least a portion of the wire portion reaching the cavity and is fixed to the support bar, which deformation prevents the wire from being drawn out of the slot. Such deformation is preferably caused by mechanical deformation of at least some wires in the cavity, such as stamping or swaging. According to the present invention, the deformation may be otherwise brought about by welding, soldering, gluing or other similar non-separating manner, in which a fastening material material is secured to the downstream end of the wire, which leads the wire to the inner wall of the cavity. Attach to.

According to another embodiment of the present invention, the support element may consist of a U-bar, which has a material thickness of approximately 1-5 mm, preferably 1.5-2 mm. The central part of the U-bar has a bend with a radius of approximately 3-6 mm. The plurality of parallel support slots are formed across the first center of the bar, the support slots having a depth corresponding to 1/4 to 1/2, advantageously 1/3 of the total height H of the U-bars. Preferably the support slot has a depth corresponding to 1/3 to 2/3 of the height h of the filter wire, so that 2/3 to 1/3 of the filter wire inserted into the slot still protrudes onto the support bar. do. The support slot may have a depth of 3-7 mm, for example 3.5 mm and the width of the top of the support slot (in the longitudinal direction of the U-bar) may be approximately 1-3 mm, for example 1.5 mm.

According to another embodiment of the invention, the filter wire is a U-bar or a partially rigid bar having a cavity machined therein by bending the base edge or at least a portion of the downstream edge of the filter wire protruding into the cavity of the support bar. It may be secured to a support slot in a back support bar. Two preferably parallel notches may be provided perpendicular to the wire at the downstream edge of the wire to provide an easily deformable or bendable flap. This notch is formed long enough to allow the flap to deform or bend to lock the filter wire in the support slot to secure the wire to the bar.

The present invention can be applied to screen cylinders with inward or outward flow of the suspension to be screened. In the inflow screen the filter wire is connected to the outer surface of the support ring and in the outflow flow to the inner surface of the ring respectively.

The present invention provides a substantially improved screening device for manufacturing and assembling such devices. The present invention in particular provides an improved method of manufacturing screening devices so that accurate and uniform screening slots, such as good tolerances with very small widths, can be produced. The new screening device provides a method of making a robust screening device with minimal burrs or other protruding elements that result in fiber accumulation.

The invention will be explained in more detail according to the accompanying drawings that follow.

1 schematically shows a planar / side view of a portion of a screening device according to a preferred embodiment of the present invention. In FIG. 1 three filter wires 10, 10 ′, 10 ′ are arranged on a partially rigid support bar 12, which is a circular upper end 13 which abuts the flow receiving portion, and side walls 15 therein. It has an elongated cross section at the bottom with a cavity with ').

The filter wires 10, 10 ′, 10 ′ have a narrow lower end portion 14, such as a downstream portion, and an upper end portion 16 that is widened upward in a funnel shape, such as an upstream portion. The wire is mounted on the support bar by inserting a narrow lower end 14 into the slot 17 formed through the top or upstream side of the support bar 12. Slot 17 is substantially perpendicular to the longitudinal axis of support bar 12. The slot 17 is also substantially perpendicular to the top surface of the support bar such that the filter wire reaches outwardly radially from the support bar.

The bottom edge 19 of the filter wires 10-10 ′ reaches the cavity 15 in the bottom of the support bar as better shown in FIG. 2. FIG. 2 also shows that the funnel top of the filter wires 10, 10 ′, 10 ′ is suitable for fitting to the similarly formed funnel top of the slot 17.

In FIG. 2, wire 10 ′ represents a wire disposed in slot 17 but not yet secured thereto. Filter wires 10, 10 ′ have been attached to support bars 12 according to different embodiments of the present invention for illustrative purposes only. Wire 10 was secured to slot 17 by mechanical deformation of bottom wire edge 19 ′. Edge 19 'is deformed such that the width of this edge exceeds the width of slot 17, preventing wires from being drawn through the slot.

The wire 10 'is attached by welding. The slight deformation of the edge 19 of the wire 10 'occurs when the wire is welded to the side wall 15' by the weld 21 formed on the edge. The weld prevents the base or edge of the wire from being drawn out of the slot. Different types of welding may be used, such as laser, TIG or plasma welding. A relatively small amount of heat is required to weld the thin wire edge to the support bar, which has a rather small material thickness. As a result, deformation can be prevented in the method according to the present invention. An additional advantage is achieved according to the invention by welding, which is carried out on the cavity side of the support bar in a position which is not in contact with the fiber suspension to be screened and which in turn causes no problems when the fibers are focused on the weld.

3 and 4 schematically show a top side view of the filter wire 10 and the support element 12 according to another embodiment of the invention. 3 shows a filter wire 10 in the form of a triangular bar, which is arranged on the U-vine support element 12 in this embodiment. The filter wire 10 has a triangular cross section A with two long sides 18 and one short side 20.

The filter wire 10 has an upstream portion 16 and a downstream portion 14. Two notches 22, 24 spaced apart from each other at approximately 8.5 mm intervals are machined at the downstream 14 or downstream edge of the filter wire. The notch here is formed before placing the filter wire on the U-bar. This notch can be formed later, if desired, if the filter wire is already placed on the U-bar.

The U-bar has a first portion 26 or central portion, which is curved or inclined, and a second support body 28. The support element is arranged in the screening device so that the first part 26 abuts the receiving suspension, which flows in the direction shown by the arrow (Fig. 2; a). The cavity 15 is formed in the U-bar and opens to the downstream side of the suspension passing through the U-bar. The cavity is somewhat clogged or suspended in suspension through the outer side of the U-bar. If desired, the cavity may be covered by a ring after connecting a filler, metal strip, or wire to the support bar. This also adds to the strength and rigidity of the structure.

The plurality of through openings, ie the support slots 17, are cut through the central surface 32, for example the central surface 32 and part of the side surfaces 34, 35 of the U-bar. The support slot is cut straight through the material so as to be formed through the opening between the upstream side of the U-bar and the cavity 15. The formed support slot 17 has a triangular cross section of the same shape as the cross section of the filter wire 10 to be connected, so that the supporting slot is suitable for receiving the wire. 3 and 4, the shape of the cut in the side surface 34 of the U-bar is similar to the cross section of the downstream edge 14 of the filter wire.

4 shows the filter wire 10 arranged in the support slot 17. Notches 22 and 24 (not shown) are disposed within the cavity 15 or U-bar, with the ends of the notch reaching almost the inner side surface of the cavity.

5 shows the filter wire 10 attached or locked to the U-bar 12. The flaps 36 (shown in broken lines) formed at the edges of the filter wires between the notches are bent in the direction of the innermost side surface 15 'of the cavity in the U-bar, so that the flap 36 extends the filter wire 10 at the U-bar. And flap 36 prevent the wire edge from separating from the U-bar. 6 shows an inverted view of the support bar and the filter wire connected thereto in FIG. 5. The flap 36 in the filter wire edge is projected through the support slot 17 into the cavity in the U-bar and bent to the inner surface of the U-bar.

7A to 7D are views in which the filter wire is fixed to the support slot in the support bar 12 by the deformation of the base portion 19 of the filter wire 10. In FIG. 7A the support bar 12 is shown in cross section through the top surface but is placed in an assembly machine with tools 40, 42. The slot 17 in the top surface of the support bar is clearly visible. The assembled and fixed filter wire 10 is shown on the right side or outlet side of the machine. The top tool 42 is easy to vertically move and is formed on the surface to match any corresponding shape of the filter wire. The tool 40 is incorporated with the deformation tool profile 44 required to deform the base portion of the filter wire to form a joint. In FIG. 7A the filter wire 10a is shown already inserted in the slot 17 and another filter wire 10b is moved to the position to be fixed.

Simultaneous movement of the upper tool 42 and the lower tool 40 in FIG. 7B generates a deformation force that conducts the base portion 19 of the filter wire 10a and forms a joint. While the filter wire 10a is deformed, the adjacent wire 10b is firmly clamped in the slot 17 to prevent the slot or support bar from being deformed under the load of the assembly.

The base portion of the filter wire 10a is deformed on the cavity side of the support bar 12 to increase the base portion material thickness of the wire section protruding into the cavity so that the deformed portion 46 is formed. The deformed portion is wider than the width of the supporting slot which prevents the base portion of the wire from reentering the slot, resulting in locking the wire in the bar. Deformation can be readily accomplished with a tool 44 that squeezes the thin edges of the wire while simultaneously holding the upper end 16 of the wire against the anvil 42 '.

In FIG. 7C the upper tool 42 and the lower tool 40 are separated and allow the upper support bar to split in all directions to take the already fixed filter wire and to place the next filter wire 10b in the tool to be assembled. In FIG. 7d the division of the support bar is completed and the new filter wire 10b is in the position to be deformed. An empty slot can now be used in which the next filter wire can be placed.

The present invention provides several advantages over prior art screening devices and methods for making the same.

Screening devices having a robust structure can be produced easily and inexpensively according to the present invention. The screening device produced is able to withstand pulses and static pressures and at the same time maintain tolerances of the screening openings at optimum levels, preferably less than ± 0.03 mm. The screening device according to the present invention does not have burrs or other elements to which fibers easily adhere and accumulate. The present invention thus provides a method of manufacturing a screen having a supporting slot width of between 0.1-0.5 mm, even <0.1 mm.

The scope of the present invention is not intended to be limited by the exemplary embodiments described above. This intention is to apply the invention broadly according to the scope of the invention as defined by the appended claims. As shown in FIGS. 3-6, it is not necessary to provide notches in the filter wires, but the embodiment of FIGS. 1-2 may be preferred in most cases. The present invention can be used to preferentially provide a planar filter plate of an upright support having connected filter wires, after which the filter plate is formed in a formed cylinder or deformation ring in which the support to which the filter wires are connected can be used, thus providing a cylindrical Form a screen basket immediately.

Claims (18)

As a screening device such as screen cylinders or curved or flat screening elements for screening, penetrating, fractionating or classifying pulp suspensions or other similar suspensions in the pulp and paper manufacturing industry, A plurality of filter wires 10 arranged at small intervals parallel to each other, the adjacent filter wires forming a screening opening therebetween, the plurality of filter wires having an upstream section and an opposite downstream section that abut the flow of the suspension, and At least one longitudinal support element 12 such as a support ring or support bar for supporting said plurality of filter wires on top Wherein the support element 12 has an upstream side surface that abuts the flow of the suspension, and the plurality of support slots 17 are formed through the upstream side surface of the support element, The support slot is shaped to accommodate the downstream section 14 of the filter wire 10, In the screening device, the filter wire 10 is fixed to the slot in the support element, The at least one support element has a cavity 15 on a downstream side surface, The plurality of support slots 17 are through openings that reach from the upstream side surface of the support element 12 to the cavity 15, Screening device, characterized in that the base part (19, 36) of the downstream section (14) of the filter wire (10) reaches through the support slot (17) to the cavity (15). The method of claim 1, The support slot extends mainly transverse to the support element, A screening device, characterized in that the filter wire is fixed to the support element by a material in the base portion (19, 36) of the wire or in the slot (17) limit area of the support element that is locally deformed. 2. The at least one support element 12 according to claim 1, wherein the at least one support element 12 consists of a bar having a U-, L- or V-shaped or other similar shape with a curved or inclined first portion 26, The convex or external side surfaces 32, 34, 35 of the curved or inclined first portion form an upstream side surface of the support element that abuts the flow of the suspension, Screening device, characterized in that the concave or internal side surface (15 ') of the curved or inclined first portion defines a cavity (15). 2. The support element (12) according to claim 1, characterized in that the support element (12) consists of a partially rigid bar having a cross section having a circular first end surface (13) and a second opposing end surface with a cavity (15) therein. Screening device. The screening device according to claim 1, wherein the support slot (17) has a depth (h ₂ ) corresponding to 0.25 to 0.50 of the total height (H) of the support elements. 2. The screening device of claim 1, wherein the support slot has a tooth (h ₂ ) of 0.3 to 0.9 of the height (h) of the filter wire. The method of claim 1, Two parallel notches 22, 24 are provided in the downstream section 14 of the filter wire perpendicular to the axis of the wire, and define a flap forming the base portion 36, And the flap is deformed by bending or stamping to secure the wire to the support element. 2. The screening device according to claim 1, wherein the deformation is provided in the base portion (19) of the filter wire (10) reaching the cavity (15) by mechanical deformation such as stamping or bending. 2. The deformation of claim 1, wherein a deformation is provided in the base portion 19 of the filter wire 10 reaching the cavity 15 by welding the base portion to at least one of the downstream side surfaces 15 ′ defining the cavity. Screening device. 2. Screening apparatus according to claim 1, characterized in that the plurality of support slots (17) are mainly perpendicular to the support element (12) and the filter wire is arranged mainly perpendicular to the support element. The screening device of claim 1, wherein the filter wire is disposed at an angle of approximately 90 ° with respect to the support element and is substantially perpendicular to the upstream surface of the support element. The screening device according to claim 1, wherein the filter wire is fixed to the support element by deforming the material of the support element within the slot limit area. A method of making a screening device such as a screen cylinder or a curved or flat screening element for screening, fractionating or sorting pulp suspensions or other similar suspensions in the paper industry, Disposing a plurality of filter wires 10 at small intervals parallel to each other to form a screening opening between adjacent wires, the wires having an upstream section and an opposite downstream section 14 that abut the flow of the suspension, and Forming a plurality of support slots 17 suitable for receiving a downstream section 14 of the filter wire in an upstream side surface of the at least one support element by machining, cutting or another similar manner, and in said support slot Inserting a filter wire to attach a plurality of wires on at least one longitudinal support element 12, such as a support ring of a support bar having an upstream side surface and a downstream side surface. In the method for producing a screening device by Forming a plurality of support slots such that the plurality of support slots reach from the upstream side surface of the support element to a cavity 15 formed on the opposite side of the support element, and Inserting the filter wire into the support slot such that at least one base portion 19, 36 of the downstream portion of the filter wire reaches the cavity through the support slot; Method for producing a screening device, characterized in that. 14. A method according to claim 13, characterized by modifying the material in the base area of the filter wire or in the slot 17 limit area of the support element to secure the filter wire to the at least one support element to prevent the base part from reentering the slot. The manufacturing method of the screening apparatus. The method of claim 13, Forming two parallel notches 22, 24 at the base of the downstream section of the wire, Inserting the base portion of the filter wire defined by the two notches so that the base portion reaches the cavity 15 in the support element through the slot, and Mechanically deforming the base portion between the notches securing the wire to the support element, such as bending or stamping Method characterized by. 14. A method according to claim 13, characterized by machining forming a plurality of parallel support slots (17) mainly perpendicular to a support element connecting the plurality of parallel filter wires to a support element perpendicular thereto. 14. A method according to claim 13, characterized by attaching the filter wire to the at least one support element by modifying the material of the support element in the slot limit area by local force directed through the upstream side surface of the support element to the support slot. . 18. The method according to claim 17, characterized in that the material in the downstream section of the filter wire in the cavity (15) formed in the support element is deformed to attach the filter wire to the at least one support element.