EP3712307A1 - Knife element for a fibre-processing machine and working element with a knife element - Google Patents

Abstract

The invention relates to a knife element (16) and a working element with a knife element (16) for a fiber processing machine with a working width (30) and a working direction (30) running transversely to the working width (31). The knife element (16) has a multiplicity of knife blades (17, 18, 19) pointing against the working direction (30) and, viewed between the knife blades (17) in the working direction (30), in each case ejection openings (20), the ejection openings (20) have a length (C) in the direction of the working width (31) and the width (D) in the working direction (31). The knife element (16) is formed from sheet metal, the ejection openings (20) in the sheet metal being in the form of passage openings and the knife blades (17) being formed by edges of the passage openings.

Description

The invention relates to a knife element for a working element of a fiber processing machine and a corresponding working element with a working width and a working direction running transversely to the working width. The working element extends over the working width and has a base body. A suction channel is arranged on the base body across the working width.

In spinning preparation plants, machines such as cleaners or cards are used which contain various work elements for cleaning, sorting, opening, carding, etc. of the fiber material to be processed. The most diverse types of fibers are processed, including cotton fibers or man-made fibers or mixtures thereof. For the separation of short fibers and trash parts, working elements with knife elements, so-called separating knives, are used. The parts or short fibers are usually separated from the separating knife by a rotating roller, with the help of which the fiber material is transported. For this purpose, an opening in the working element against the surface of the rotating roller and the fiber material transported on it is provided in front of the separating knife, which opening serves as an ejection opening for the parts separated from the fiber material by the separating knife. After the parts rejected by the ejector knife have passed the ejection opening, they are fed to a suction channel and conveyed away. Various types of reject knives are used in cleaning machines or cards in spinning mill preparation.

Working elements of this type are known in various designs. For example, the writing describes CH 639 434 A5 a dirt separator, which has a knife blade that is radially spaced from the drum of a card and serving as a knife element, as well as a collecting rail that is also radially spaced apart. A gap is left between the catch rail and the knife blade. The space delimited by the knife blade and the collecting rail is covered and forms a vacuum suction chamber.

Another cleaning element with a separating knife is disclosed in the document DE 39 02 204 A1 . The ejection distance is determined by the distance between the knife blade and the upstream element. The dirt separated through the ejection opening with the aid of the knife blade is guided along the knife blade to a suction channel. A guide element is attached to the rear of the upstream element which can be swiveled into the ejection opening and thereby changes the size of the ejection opening and the separation behavior of the cleaning element.

The European patent application EP 0 388 791 A1 also discloses a device for separating dirt with the aid of a knife blade, a carding element being arranged in front of the knife blade and a guide element being arranged behind it.

The disadvantage of the known devices is that the knife elements, due to their structure within the working elements with an upstream guide surface and a downstream carding surface for removing dirt and short fibers, take up a large part of the available peripheral surface of the rollers facing them. Due to the necessary size of the suction channel, a large space requirement arises for the use of a separating knife. As a result, only a limited number of removal knives is possible on the available circumference of a roller. This means that a correspondingly large separation opening or a large distance between the element in front of the knife blade and the surface of the opposite roller must be set in front of the separating knives or knife blades in order to achieve the required separation rate. The large distance between the element in front of the knife blade and the surface of the opposite roller in combination with a large discharge opening causes the knife blade to penetrate deeper into the fiber material. However, this results in an increase in the risk of increased excretion of gut fibers. Good fibers are fibers that are present in the fiber material and, due to their length, should not be separated but should be fed to further processing. Work items for excretion of Dirt and short fibers should therefore, if possible, not separate any good fibers from the fiber material.

The object of the present invention is to propose a knife element, or a working element, which does not have the disadvantages of the known prior art and allows the number of knife blades to be increased and thus to better utilize the available circumference of a roller. In addition, the object of the present invention is to enable a flexible configuration of the arrangement of the knife blades and thus to achieve an improvement in the separation with a lower loss of good fibers.

The object is achieved by the features in the characterizing part of the independent patent claims.

To achieve the object, a new type of knife element is proposed for a working element of a fiber processing machine with a working width and a working direction running transversely to the working width. The knife element has a plurality of knife blades pointing against the working direction and a plurality of ejection openings, one ejection opening being assigned to a knife blade and the ejection openings having a length in the direction of the working width and a width in the working direction. By attaching a large number of knife blades in a knife element, several ejection openings and thus also several knife blades which function as ejector knives can be created in a narrow space. As a result, there is also no need to assign a suction channel to each ejection opening. The ejection openings of all knife blades of a knife element can be assigned in a single common suction channel, which results in further space savings. The large number of knife blades also enables the trash particles to be gently peeled off from the fiber fleece that is passed under the knife blades, whereby good fibers can be avoided. By uniting a With a large number of knife blades in one knife element, a diverse and variable arrangement, shape and size of the individual knife blades is possible.

The knife element is formed from a sheet metal, the ejection openings in the sheet metal being in the form of passage openings and the knife blades being formed by edges of the passage openings. The passage openings and thus also the ejection openings and knife blades can be produced by a punching process known from the prior art. In the case of smaller knife elements, however, it is also conceivable to machine them out of thicker sheets of up to 40 mm. By machining the ejection openings, they can be arranged obliquely at an angle β of 10 to 80 degrees, particularly preferably 30 to 70 degrees, with respect to the sheet metal surface.

The sheet metal preferably has a thickness of 0.05 mm to 2.0 mm, particularly preferably 0.1 mm to 0.8 mm. The thin sheet metal makes it possible to design knife elements which cover a larger section of a roll circumference, since the knife elements can be molded to the shape of the roll surface. It has been shown that a sheet thickness of 0.3 mm results in good deformability with sufficient stability.

In the case of thin sheet metal or for reasons of assembly technology, it is advantageous if the knife element comprises a frame in which the sheet metal is inserted. Devices required for fastening the knife element or through holes required for a screw connection can be attached to the frame. In the event that a seal is necessary between the knife element and a counter-element, the knife element preferably has a frame. With this construction, a thin sheet metal thickness can be selected for the knife element even under high loads.

The knife element advantageously has a width of 30 mm to 500 mm and a length of 20 mm to 800 mm. A length of the adapted to the working width Knife elements enables the knife elements to be introduced in modules. Different versions of knife elements can be provided over the course of the working width. The shorter the length of the knife elements is chosen, the smaller the sheet metal thickness can be chosen, which has manufacturing advantages for the execution of the edges of the ejection openings for the formation of the individual knife blades. The knife element particularly preferably has a width of 40 mm to 150 mm and a length of 100 mm to 500 mm.

The passage openings which form the ejection openings can be provided as simple punched openings or with a radius of 0.1 mm to 2.0 mm, particularly preferably 0.3 mm to 1.0 mm, on the side opposite the knife blades. A rounding of the edges from the punching process on the side of the knife element facing away from the fiber material leads to an improved removal of the separated parts into the suction channel. It is also conceivable to design the ejection openings as so-called beads. One edge of the ejection opening is bent slightly out of the plane of the sheet metal and forms the knife blade. The individual knife blades protrude 0.1 mm to 2.0 mm, particularly preferably 0.3 mm to 1.0 mm, from the plane of the ejection openings and produce the effect of a previously used individual knife blade reaching into the fiber material. The width of the knife elements is structurally adapted to their place of use. Experience has shown that the usual widths of working elements in the various spinning preparation machines vary widely, for example a width in working elements of cards of 32 mm is usual, whereas in cleaning machines widths are used which can correspond to up to a quarter of the roller circumference.

The ejection openings preferably have a length to width ratio of less than 20 to 1. So that the edge formed by the ejection opening, which is used as the knife blade, has an effect corresponding to an ejection knife, the longer edge of the ejection opening extends in the direction of the working width. It has been shown that square ejection openings with a corresponding edge length still meet the requirements. It is an advantage if the ejection openings have a length of 5 mm to 200 mm, preferably 10 mm to 30 mm, and a width of 2 mm to 15 mm, preferably 3 mm to 8 mm. The ejection openings are also advantageously spaced from one another not more than 0.1 mm to 20.0 mm, preferably 0.5 mm to 5.0 mm, in the direction of the working width and in the working direction. A close arrangement of large ejection openings has an effect on the stability of the knife element and may need to be compensated for by the choice of the size of the knife elements or an increased sheet metal thickness.

The ejection openings can be designed in various geometric shapes, with a rectangular shape or rectangular shape rounded at the ends being preferred. This results in correspondingly long knife blades in relation to the length of the ejection opening. However, trapezoidal or triangular ejection openings are also conceivable.

A wide variety of variants are possible for the arrangement of the ejection openings and thus also the knife blades within a knife element. In a preferred embodiment, the width of successive ejection openings decreases in each case in the working direction. As a result, the ejection openings are becoming increasingly narrow as seen in the working direction. As a result, the excretion is smaller and the fiber guidance is better when viewed in the working direction. It has been found that as the width of the ejection opening decreases, the largest width is 2 mm to 20 mm, preferably 3 mm to 10 mm, and for the smallest width 0.1 mm to 12 mm, preferably 2.0 mm to 5.0 mm, a good compromise between fiber guidance and excretion result. Another variant is that ejection openings arranged one behind the other, viewed in the working direction, have an offset arranged in the direction of the working width. This ensures that there is no area without a knife blade across the working width. The different variants can also be combined, for example the first ejection openings can be arranged without offset and subsequently offset and narrowing ejection openings can be provided.

It is also advantageous if a large number of compensation openings are provided to the side of the discharge openings and / or after the discharge openings, the compensation openings each having an area of less than 50% of the area of the smallest discharge opening in the knife element. The compensation openings are used to create a flow compensation. By decoupling the flow passing the knife blades and the turbulence occurring in the edge areas of the knife element, it is possible to achieve a defined, uniform flow in the area of the knife blades and thus the ejection openings. This in turn contributes to a reduction in good fiber excretion and also prevents fibers from getting caught at the edges of the discharge openings and causing blockages. The compensation openings can be designed in any shape, for example rectangular or circular. The compensation openings can be arranged in rows or with an offset. It has proven useful, with a length of the knife element of 200 mm and a width of the knife element of 100 mm, one to two rows on each side of the knife blades and two rows of rectangular compensation openings with a respective area of the compensation openings of 30% of the area of the smallest ejection opening were used. For knife elements of different sizes and different designs and arrangements of the ejection openings, the ideal number, design and arrangement of the compensation openings must be determined by means of fluidic tests.

At least two guide rails are advantageously provided on the knife element in the working direction, the guide rails being guided over the entire width of the knife element. The guide rails prevent the knife element from being brought too close to the opposite roller surface when it is used in a machine. The guide rails consist of narrow sheet metal strips which are attached to the knife element by welding, soldering or gluing. The guide rails are only a few tenths of a millimeter high so as not to hinder the elimination process. The guide rails can be arranged straight, inclined, angled, bent or offset over their course along the working direction. The guide rails can be made of the same material as the knife element or of plastic. Alternatively, the function of the guide rails can be fulfilled by a corresponding embossing of the knife elements. Elevations, for example in the form of knobs, are formed in the knife element between the ejection openings by a manufacturing process of the embossing, which prevent the knife element from being brought too close to the opposite roller surface when it is used in a machine. The knobs can have any shape, such as triangular, round or square. Other manufacturing processes as an alternative to embossing are also conceivable for creating the elevations, for example by applying weld points or other materials to the knife element.

A novel working element for a fiber-processing machine with a working width and a working direction running transversely to the working width is also proposed, the working element extending over the working width and having a base body. A suction channel is arranged on the base body across the working width. The working element is provided with at least one knife element as described above on a side facing away from the suction channel. The knife element is held on the base body and has a multiplicity of knife blades and ejection openings between the knife blades or the knife blades and the base body. The discharge openings are connected to the suction channel through the base body. By attaching a large number of knife blades in a knife element which is fastened to the base body, several ejection openings can be created in a narrow space. A suction channel is also not assigned to each ejection opening. The ejection openings of all knife blades of a knife element are assigned to a single common suction channel. The large number of knife blades also enables the trash particles to be gently peeled off from the fiber fleece that is passed under the knife blades, whereby good fibers can be avoided.

The large number of knife elements used, and thus knife blades, also enables the knife blades to be distributed in various ways over the area of the roller covered by the working element. By arranging knife blades in several rows, the individual knife blades can be made short. Several knife blades can be arranged next to one another in a row over the working width, whereby the arrangement of the knife blades from adjacent rows can be provided with an offset in the direction of the working width. Other patterns of arranging individual knife blades in rows in the direction of the working width or across it are also conceivable. Knife blades can also be arranged in rows at a certain angle to the direction of the working width. With an additional variation of the length of the individual knife blades or the width of the ejection openings as well as the distances between the individual knife blades or ejection openings, there is a wide range of design options for the knife elements used. The arrangement, size and design of the knife blades can be individually adjusted to the product to be processed.

The knife element is preferably releasably attached to the base body. The construction of the working element with a detachable knife element attached to it means that the knife setting can be adjusted by simply replacing the knife element and the difficult adjustment of the knife blades as known from the prior art is no longer necessary. The knife element can be attached to the base body by using a support body in order to facilitate assembly and disassembly. The same principle can also be applied to a change in the ejection distance due to the new construction according to the invention. If, due to a change in the product to be processed, a larger or smaller ejection distance is to be set or the working element is to be limited to a small number of knife blades, this can be done by simply changing the knife element. There is also no need to pre-set the working elements by precisely measuring the position of the knife blades in relation to the bearing points of the working element over the entire working width. By using a knife element which cannot be adjusted at a height relative to the bearing points of the working element, the setting is possible a distance between the knife blades and a surface of the opposite roller is given solely by the setting of the working elements in the bearings.

In an advantageous embodiment, at least one air guide element is arranged between the suction channel and the knife element in the base body. The fact that a large number of consecutive knife blades and ejection openings are arranged results in air turbulence which is caused by the suction channel and the movement of the fiber material. In order to minimize the influence of the suction points arranged one behind the other, it is advantageous to guide or channel the air flowing to the suction channel through air guide elements.

In a first embodiment, the air guide elements are arranged inclined at an angle α of 10 to 50 degrees to or against the knife element. The inclination of the air guide elements must be adapted to the design of the suction channel. An air guide element is assigned to each or every second ejection opening. This version is preferably used when the suction channel connects directly to the knife element.

In an alternative embodiment, the air guide element is arranged parallel to the knife element at least in the area of the ejection openings. As a result, a narrow transport space is formed between the knife element and the suction channel, which is preferably guided into the suction channel at the end of the knife element, viewed in the working direction. On the side of the knife element opposite the suction channel, a passive air supply is preferably created in this transport space between the air guide element and the knife element, whereby an air flow is generated over the knife element in the working direction. Furthermore, it is advantageous if at least one supply air duct is provided in the base body, the supply air duct opening into the transport space between the knife element and the air guide element. The supply air duct enables a controlled, active supply of air into the transport space, for example through the use of compressed air.

Figur 1

Schematische Darstellung einer Karde nach dem Stand der Technik;

Figur 2

Schematische Darstellung einer ersten Ausführungsform eines Arbeitselementes nach der Erfindung;

Figur 3

Schematische Darstellung einer zweiten Ausführungsform eines Arbeitselementes nach der Erfindung;

Figur 4

Ansicht einer ersten Ausführungsform eines Messerelementes nach der Erfindung;

Figur 5

Ansicht einer zweiten Ausführungsform eines Messerelementes nach der Erfindung;

Figur 6

Ansicht einer dritten Ausführungsform eines Messerelementes nach der Erfindung;

Figur 7

Ansicht einer vierten Ausführungsform eines Messerelementes nach der Erfindung;

Figur 8

Ansicht einer fünften Ausführungsform eines Messerelementes nach der Erfindung und

Figur 9 bis Figur 12

Schnittdarstellungen verschiedener Ausführungsformen von Messerelementen an der Stelle X nach der Figur 8

In the following, the invention is explained using exemplary embodiments and explained in more detail by means of drawings. Show it

Figure 1

Schematic representation of a card according to the prior art;

Figure 2

Schematic representation of a first embodiment of a working element according to the invention;

Figure 3

Schematic representation of a second embodiment of a working element according to the invention;

Figure 4

View of a first embodiment of a knife element according to the invention;

Figure 5

View of a second embodiment of a knife element according to the invention;

Figure 6

View of a third embodiment of a knife element according to the invention;

Figure 7

View of a fourth embodiment of a knife element according to the invention;

Figure 8

View of a fifth embodiment of a knife element according to the invention and

Figure 9 to Figure 12

Sectional representations of various embodiments of knife elements at point X after Figure 8

Figure 1 shows a schematic representation of a card 1 according to the prior art. After it has passed through various process stages in a blow room, fiber material 2 arrives in a licker-in 3. The fiber material 2 is opened by the rollers and working elements 12 contained in licker-in and at the same time freed from some of the impurities it contains. The last lickerin of the lickerin 3 finally transfers the fiber material to the drum 4 of the card 1, which completely dissolves the fiber material into individual fibers, cleans and parallelises it. For this purpose, the drum 4 works with revolving lids 5 and various working elements 12. The drum 4 is moved in a direction of rotation 13 and leads the fibers from the lickerin 3 to the doffer 5. The fibers are passed through a pre-carding zone 9, then past the revolving flats 5 and over a Post carding zone 10 promoted to the customer 6. In the pre-carding zone 9 as well as the post-carding zone 10, working elements 12 are used. The working elements 12 used include carding elements for parallelizing the fibers and separating elements for separating trash parts and short fibers. Between the doffer 6 and the licker-in 3, the fiber material, viewed in the direction of rotation 13 of the drum 4, still passes through an undercarding zone 11. In the undercarding zone 11, separation elements are mostly not used today. After the fibers have in some cases made several revolutions on the drum 4, they are removed from the drum 4 by a doffer 6 in the form of a nonwoven fabric and formed into a card sliver 8 with a sliver forming unit 7. The card sliver 8 is then placed in a can for further transport (not shown).

Figure 2 shows a schematic representation of a first embodiment of a working element 12 according to the invention. The working element 12 has a working width 31 and is formed from a base body 14 which, in the exemplary embodiment shown, is formed from two parts and joined together via a bracket. The base body is shaped into a suction channel 15. A knife element 16 is attached to the base body 14 below the suction channel 15. The attachment of the knife element 16 to the base body 14 itself is not shown and can be formed in accordance with the known prior art by a releasable connection, for example screws, clips, or a permanent connection, for example welding, gluing. Ejection openings 20 are provided in the knife element 16, which create a connection from the suction channel 15 to a surface of a roller which is opposite to the working element 12. The edges of the ejection openings 20 opposing a working direction 30 are designed as knife blades 17. Seen in the working direction 30, several knife blades 17 and the ejection openings 20 assigned to each knife blade are arranged one behind the other. All ejection openings 20 are connected to the suction channel 15, which results in a large number of knife blades 17 with only one suction channel 15. In order to improve the flow from the discharge openings 20 into the suction channel 15, guide elements 23 are provided. The guide elements 23 are held inclined in the base body 14 at an angle α relative to the working direction 30.

Figure 3 shows a schematic representation of a second embodiment of a working element 12 according to the invention. The working element 12 is compared to the execution according to Figure 2 shown with a much larger width F. A suction channel 15 is attached to a base body 14. The suction channel 15 is attached to one end of the working element 12 on the base body 14. The contact surfaces between the base body 14 and the suction channel 15 are provided with a seal 26. A knife element 16 is attached to the side of the base body 14 opposite the suction channel 15. The knife element 16 has a shape that is curved in the working direction 30 in adaptation to a surface of a roller which is opposite in the operating state. In the embodiment shown as an example, the knife element 16 is connected to the base element 14 via a support body 22. Associated with the knife element 16 is a guide element 23 which is arranged over an effective width of the knife element 16 in such a way that a transport space 24 is formed along the knife element 16, viewed in the working direction. The transport space 24 is connected to the suction channel 15 by the base body 14. At the end of the working element 12 seen against the working direction 30, the transport space 24 is connected to the environment via an alternative connection 18 placed in the base body 14. Due to the arrangement shown, a negative pressure prevailing in the suction channel 15 causes an air flow from the alternative connection 18 along the knife element 16 in the working direction 30 through the transport space 24 to the suction channel 15. With the air flow, the trash parts and short fibers separated by the knife element 16 are transported into the suction channel 15 guided. When processing heavily soiled fiber material, compressed air can additionally be introduced into the transport space 24 through a supply air duct 25. The supply air duct 25 is arranged in such a way that the air flow generated by the negative pressure in the suction duct 15 is reinforced or supported in the transport space 24.

In the in Figure 3 The exemplary embodiment shown, the base body 14 is designed such that the suction channel 15 from the in Figure 3 position shown in Opposite position seen in the working direction 30 can be offset above the alternative connection 18. The consequence of this is that the direction of the air flow in the transport space 24 is reversed relative to the working direction 30.

Figure 4 shows a view of a first embodiment of a knife element 16 according to the invention. The knife element has a length A and a width F, the width F extending in the working direction 30. The working direction 30 is given by the arrangement of the knife blades 17, which oppose the working direction 30. The knife blades 17 are defined by the edges of the ejection openings 20 made in the knife element 16 in the form of passage openings. The ejection openings 20 are arranged in several rows along the length A that are offset from one another over the width F. In the embodiment shown, the ejection opening in the entire knife element 16 has the same rectangular shape and size with a length C and a width D. A spacing E is provided between the individual ejection openings 20. This is to be selected so that overall no weakening of the knife element 16 occurs through the ejection openings 20, so that the knife element 16 has sufficient dimensional stability.

In the in Figure 5 The second embodiment of a knife element 16 shown is the rectangular ejection openings 20 with the edges formed to knife blades 17 lying in the working direction 30, also arranged in corresponding rows along the length A. There is no provision for an offset of the adjacent rows in the working direction 30. However, the width of the ejection openings 20 in the working direction decreases from row to row over the width F of the knife element 16, from a greatest width D1 to a smallest width Dn. The length C of all ejection openings 20 and the spacing E of the ejection openings 20 of a row are the same. The spacing of rows following one another in the working direction 30 steadily decreases from a greatest distance E1 to a smallest distance En in the working direction.

In Figure 6 In a third embodiment of a knife element 16 with a length A and a width F, a uniform distribution of the ejection openings 20 is shown. The ejection openings 20 with the edges formed into knife blades 17 lying in the working direction 30 are each designed with identical lengths C, widths D and spacing E. The ejection openings 20 are designed in their geometric shape, for example, as rectangles with rounded ends.

In Figure 7 is a fourth embodiment of a knife element 16 based on the embodiment according to Figure 5 shown. The ejection openings 20 with the edges formed into knife blades 17 lying in the working direction 30 are arranged in accordance with FIG Figure 5 intended. The ejection openings 20 are only arranged in a central area of the knife element 16. Compensating openings 19 are provided laterally in an edge region as seen in the working direction 30 and at the end of the knife element 16. The compensation openings 19, which contribute to an improvement in the edge flows during operation of the knife element 16, are designed to be considerably smaller in size than the ejection openings 20. The compensation openings 19 do not have the function of a separation, which is why their edges are not designed as knife blades. The compensation openings 19 serve to balance the flow between an upper and a lower surface of the knife element 16, which faces the fiber material during operation Figure 7 are shown by way of example in the working direction over the width F one behind the other and over the length A two rows of compensation openings 19. The distances between the compensation openings 19 as well as their geometric size is to be determined by flow tests and is also based on the location of the knife elements 16, for example the flow conditions on a roller in a cleaning machine differ significantly from a drum in a card.

In Figure 8 a fifth embodiment of a knife element 16 with a length A and a width F a uniform distribution of the ejection openings 20 is shown. The ejection openings 20 with the edges, which lie in the working direction 30 and are designed to form knife blades 17, are rectangular in shape with an identical size. In a left-hand half of the knife element 16 is an embodiment with guide rails 27 and a right-hand half of the knife element 16 is an embodiment with knobs 21. The guide rails 27 consist of narrow and a few tenths of a millimeter thick sheet metal strips which are attached to the knife element 16 by welding, soldering or gluing. The knobs are introduced into the knife element 16 by an embossing process. The guide rails 27 as well as the knobs 21 represent a locally limited elevation and serve to prevent the knife element 16 from being brought too close to the surface of an opposing roller during use. The surfaces of such rollers are often equipped with a large number of teeth or needles for transporting the fiber material. The guide rails 27 or the knobs 21 come into contact with the teeth or needles before the knife blades 17 can be damaged by the teeth or needles.

Figure 9 to Figure 12 show sectional views of various embodiments of knife elements 16 at point X after FIG Figure 8 . In Figure 9 a knife element 16 is shown with ejection openings 20 with a width D, the edges of which form the knife blades 17. The ejection openings 20 are designed as passage openings in a sheet metal with the sheet thickness B and with a spacing E from one another. In order to be able to use the smallest possible sheet metal thickness, the knife element 16 is provided on its outer edge with a frame 28 to increase the dimensional stability. The frame 28 is connected with a fastening 29, for example with a screw connection, to the sheet metal to form the knife element 16.

In Figure 10 a knife element 16 is shown with ejection openings 20 with a width D, the edges of which form the knife blades 17. The ejection openings 20 are designed as passage openings in a sheet metal with the sheet thickness B and with a spacing E from one another. On a side of the knife element 16 facing away from the knife blades 17, the edges of the ejection openings 20 are rounded with a radius R. The rounding of the edges of the ejection openings 20 facilitates the removal of the trash and short fibers that have been separated out and thus prevents blockages.

In Figure 11 a knife element 16 is shown with ejection openings 20 with a width D, the edges of which form the knife blades 17. The ejection openings 20 are designed as passage openings in a sheet metal with the sheet thickness B and with a spacing E from one another. The knife element 16 is made of sheet metal with a large sheet thickness B, the ejection openings 20 being cut out of the sheet metal, for example by laser cutting or milling. This enables the ejection openings 20 to be arranged obliquely in their course through the sheet metal at an angle β.

In Figure 12 a knife element 16 with ejection openings 20 with a width D is shown. The ejection openings 20 are designed as passage openings in a sheet metal with the sheet thickness B and with a spacing E from one another. In this case, the passage openings are embodied as beads, the outer edges of the beads representing the knife blades 17. As a result of this manufacturing process, the knife blades 17 protrude from the surface of the knife element 16 by a protrusion G. This in turn leads to an increase in the excretion rate.

The present invention is not restricted to the illustrated and described exemplary embodiments. Modifications within the scope of the patent claims are just as possible as a combination of the features, even if these are shown and described in different exemplary embodiments.

Legend

1

Card

2

Fiber material

3

Lickerin

4th

drum

5

Revolving lid

6th

customer

7th

Banding unit

8th

Sliver

9

Pre-carding zone

10

Post-carding zone

11

Lower carding zone

12

Work item

13

Direction of rotation

14th

Base body

15th

Suction duct

16

Knife element

17th

Knife blades

18th

Alternative connection

19th

Compensation opening

20th

Discharge opening

21st

Nub

22nd

Support body

23

Guiding element

24

Transport space

25th

Supply air duct

26th

poetry

27

Guide rail

28

frame

29

Attachment

30th

Working direction

31

Working width

A.

Length of knife element

B.

Sheet thickness

C.

Length of discharge opening

D.

Wide discharge opening

D1

Largest width ejection opening

Dn

Smallest width discharge opening

E.

Spacing between ejection openings

E1

Largest distance between discharge openings

En

Smallest distance between discharge openings

F.

Width knife element

G

Protruding knife blade

R.

Radius discharge opening

α

Angle guide element

β

Ejection opening angle

Claims (15)

Knife element (16) for a working element (12) of a fiber processing machine with a working width (31) and a working direction (30) running transversely to the working width (31), characterized in that the knife element (16) has a plurality of counter-working direction (30 ) pointing knife blades (17) and a plurality of ejection openings (20), with one ejection opening (20) being assigned to a knife blade (17) and the ejection openings (20) having a length (C) in the direction of the working width (31) and a Width (D) in the working direction (30) and that the knife element (16) is formed from sheet metal, the ejection openings (20) in the sheet metal in the form of passage openings and the knife blades (17) being formed by edges of the passage openings. Knife element (16) according to Claim 1, characterized in that the sheet metal has a thickness of 0.05 mm to 2.0 mm. Knife element (16) according to one of the preceding claims, characterized in that the knife element (16) comprises a frame (28) into which the sheet metal is inserted or which supports the sheet metal. Knife element (16) according to one of the preceding claims, characterized in that the ejection openings (20) have a ratio of length (C) to width (D) of less than 20 to 1. Knife element (16) according to one of the preceding claims, characterized in that the width (D) of successive ejection openings (20) decreases in each case in the working direction (30) Knife element (16) according to one of the preceding claims, characterized in that the geometric shape of the ejection openings (20) is rectangular or oval. Knife element (16) according to one of the preceding claims, characterized in that ejection openings (20) arranged one behind the other as seen in the working direction have an offset arranged in the direction of the working width (31). Knife element (16) according to one of the preceding claims, characterized in that , viewed in the working direction (30), a plurality of compensation openings (19) is provided to the side of the ejection openings (20) and / or after the ejection openings (20), the compensation openings (19 ) each have an area of less than 50% of the area of the smallest ejection opening (20) in the knife element (16). Knife element (16) according to one of the preceding claims, characterized in that at least two guide rails (27) are provided on the knife element (16) in the working direction (30), the guide rails (27) over the entire width (F) of the knife element ( 16) are performed. Working element (12) for a fiber-processing machine (1) with a working width (A) and a working direction (30) running transversely to the working width (31), the working element (12) extending over the entire working width (31) and a base body ( 14), a suction channel (15) being arranged on the base body (14) across the working width (31), characterized in that the working element (12) is provided with at least one knife element (16) on a side facing away from the suction channel (15) is, wherein the knife element (16) is held on the base body (14) and a plurality of knife blades (17, 18, 19) and between the knife blades (17) or the knife blades (17) and the base body (14) ejection openings (20) which are connected to the suction channel (15) by the base body (14). Working element (12) according to Claim 10, characterized in that the knife element (16) is detachably attached to the base body (14). Working element (12) according to claim 10 or 11, characterized in that at least one air guiding element (23) is arranged between the suction channel (15) and the knife element (16) in the base body (14). Working element (12) according to claim 12, characterized in that the air guide element (23) is arranged inclined at an angle (a) relative to the knife element (16). Working element (12) according to Claim 12, characterized in that the air guide element (23) is arranged parallel to the knife element (16) at least in the area of the ejection openings (20, 21, 22). Working element (2) according to claim 14, characterized in that at least one supply air duct (25) is provided in the base body (14), the supply air duct (25) entering the transport space (24) between the knife element (16) and the air guiding element (3) flows out.

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