Screen ring band

Abstract

A sieve ring belt (10) for transporting a fiber assembly (6) to be compressed over a suction slot (9) of a compression device (2) of a spinning machine. The sieve ring belt has an annular circumference. A plurality of adjacent longitudinal wires (15) are arranged in a circumferential direction (U) and a plurality of adjacent cross wires (16) are arranged transversely to the circumferential direction (U). There is a spacing (AL, AQ) between adjacent longitudinal wires (15) and adjacent cross wires (16), which forms a free surface, so that the sieve ring belt (10) is permeable to air. The adjacent longitudinal wires (15) have a thinner cross section than the adjacent cross wires (16).

Description

Technical Field

[0001] The present invention relates to an annular filter belt for transporting an assembly of fibers to be compressed above the suction slit of the compression device of a spinning machine. The filter belt has a plurality of adjacent longitudinal filaments in the circumferential direction and a plurality of adjacent transverse filaments in the transverse direction, wherein there is a gap between the adjacent longitudinal filaments and the adjacent transverse filaments, the gap forming a free surface, thereby allowing the filter belt to be permeable to air. Background Technology

[0002] In the drafting device, the fiber assembly, after being drafted, leaves the device with a certain width and is then wound tightly into a relatively small diameter yarn. The yarn contains edge fibers that are not properly incorporated into the twisted yarn and therefore contribute little to its strength. To increase the yarn's strength, a compression zone is located downstream of the twisting zone in the drafting device. In this compression zone, the fibers are compressed relative to each other, resulting in a narrower fiber assembly. The resulting yarn is more uniform, stronger, and less prone to pilling.

[0003] The primary method used is a suction tube to compress the fiber assembly, which is surrounded by a breathable annular filter belt. The filter belt slides above a suction slit in the suction tube, which is angled relative to the direction of movement of the fiber assembly. The direction of movement of the fiber assembly roughly corresponds to the circumferential direction of the filter belt. The fiber assembly is transported on the filter belt and compressed along the suction edge of the suction slit.

[0004] German patent DE 10104 182 A1 discloses a breathable conveyor belt for transporting an assembly of fibers to be compressed above the suction slit in the compression zone of a spinning machine. This conveyor belt is constructed as a woven belt and is formed by warp lines extending in the transport direction of the fiber assembly and transverse lines extending across the transport direction of the fiber assembly. The net distance between the two warp lines is greater than the net distance between the two transverse lines. Therefore, a conveyor belt should be provided that ensures a sufficiently large airflow while minimizing the loss of fibers.

[0005] The disadvantage of this filter ring belt is that it wears out relatively quickly during use. Furthermore, the fibers have limited transverse mobility on the surface of the filter ring belt. Therefore, it is difficult to compress the fiber aggregate at the suction edge. Summary of the Invention

[0006] In view of this, the object of the present invention is to provide a wear-resistant filter belt that also allows the fiber assembly to move well transversely to the circumferential direction of the filter belt.

[0007] The solution of the present invention to achieve the above-mentioned objective is a filter belt having the features of claim 1.

[0008] To transport the fiber assembly to be compressed above the suction slit of the compression device of a spinning machine, a screen belt has an annular circumference. Multiple adjacent longitudinal filaments are arranged circumferentially on the screen belt, and multiple adjacent transverse filaments are arranged transversely to the circumferential direction. Spacing exists between adjacent longitudinal and transverse filaments, forming free surfaces, the so-called screen surface, thereby allowing the screen belt to be permeable to air. These spacings can also be referred to as mesh widths. According to the invention, the longitudinal filaments have a thinner cross-section than the transverse filaments.

[0009] In the filter belt of this invention, the use of finer warp yarns and coarser weft yarns offers significant advantages. The filter belt with coarser weft yarns exhibits greater abrasion resistance. This is because the coarser weft yarns, transverse to the circumference of the filter belt or transverse to the transport direction of the fiber assembly, lie flat on the suction tube, while the warp yarns are tensioned so that they do not press against the suction tube even under the load of the compression roller. Therefore, wear occurs first on the thicker weft yarns. This extends the potential wear time and correspondingly extends the service life of the filter belt. The finer warp yarns also retain the low bending stiffness required for the filter belt. Furthermore, the filter belt moves around the smaller radius of the suction tube without gaps. Another advantage is that the fibers are primarily located on the back side of the coarser and more closely spaced weft yarns. Consequently, the fibers of the fiber assembly move more easily transversely to the spinning device, thus being compressed more tightly. If possible, due to the larger spacing between the longitudinal filaments, the fibers experience less obstruction from the longitudinal filaments during transverse movement.

[0010] A particular advantage of this invention is that, if possible, the thinner longitudinal filaments only contact the suction tube with a smaller clamping force after a certain period of operation, when corresponding wear occurs on the transverse filaments. While a filter belt formed by thickened transverse and longitudinal filaments may be advantageous in terms of wear resistance, it has disadvantages in terms of the lateral mobility of the fibers and the circumferential flexibility of the filter belt, and thus in achieving a gapless connection between the suction tube and the filter belt. These disadvantages can be avoided with the filter belt of this invention.

[0011] A particularly advantageous embodiment of the filter belt is that the longitudinal filaments are arranged within the surface formed by the turning points of the transverse filaments. Thus, this top surface of the filter belt is formed by the transverse filaments. Because the longitudinal filaments are thinner, the fabric can be made in such a way that the longitudinal filaments, at least in their newest state, are always at most at the level of the transverse filaments, but preferably below them. Accordingly, the longitudinal filaments are not exposed to the transverse filaments. The longitudinal filaments are preferably below the transverse filaments, but at most on the same top surface as the transverse filaments. Therefore, before wear, the longitudinal filaments are largely protected by the thicker transverse filaments. As a result, the filter belt can be used for a longer period and retains good lateral displacement characteristics of the fibers on the filter belt for an extended time.

[0012] Advantageously, the warp yarns have less serration than the weft yarns. This can also be called inlay or crimp. Inlay refers to the ratio of the length of the filaments woven into the fabric to the length of those filaments in their drawn state. The smaller the inlay, the greater the draw of the filaments in the fabric. In this case, this means that the warp yarns of the particularly advantageous filter ring have less inlay than the weft yarns. Therefore, the spacing between the turning points of the warp yarns is smaller than the spacing between the turning points of the weft yarns. When the warp yarns are weft yarns, the filter ring is woven with a smaller weft inlay. The serration of the warp or weft yarns is minimal, or if the warp or weft yarns extend in a generally straight line, they barely cross the weft or cross yarns. Minimal serration contributes to better movement resistance in the fabric.

[0013] Advantageously, the warp filaments extend generally in a straight line. Therefore, the warp filaments are not woven into the fabric or are barely woven into it. While this reduces the stability between the cross filaments, it improves abrasion resistance and the ability of the fibers to move laterally very easily on the filter belt. This is because the time it takes for the cross filaments to wear down to the same height as the thinner warp filaments, or for the filter belt to break, is extended.

[0014] Furthermore, advantageously, the spacing between adjacent longitudinal filaments is greater than the spacing between adjacent transverse filaments. The narrow spacing of the transverse filaments is compensated for in terms of mesh width by the larger spacing of the longitudinal filaments. Conversely, due to the narrower arrangement of the transverse filaments, the free screen surface will not be too large. If the screen surface is too large, more and more fibers will be drawn through. Therefore, it is advantageous to provide a screen surface that, on the one hand, allows the fibers to adhere sufficiently to the screen belt, but on the other hand, allows the fibers to continue to move laterally with as few fibers as possible passing through the screen belt and being drawn away.

[0015] Advantageously, the free surface between the longitudinal and transverse fibers, i.e., the screen surface, corresponds to 20% to 60% of the surface area of ​​the screen belt, preferably 30% to 50%. The suitable size of the screen surface depends in particular on the type and size of the fibers to be compressed in the fiber assembly.

[0016] Also particularly advantageously, the transverse filaments have a diameter that is 10% to 80% larger than the diameter of the longitudinal filaments. The suitable diameter of the filaments here also depends primarily on the type and size of the fibers to be compressed in the fiber assembly. Furthermore, the service life, that is, the duration of wear resistance of the filter ring belt, and the mobility of the fibers are also affected.

[0017] Particularly advantageously, the filter ring belt has a plain weave or a twill weave. This allows for simple fabrication of the filter ring belt. With a plain weave, the fabric exhibits excellent shape stability and fits perfectly with the suction tube without gaps. This results in excellent resistance and stability of movement. With a twill weave, different movement directions or different sides of the filter ring belt can be fabricated.

[0018] Furthermore, advantageously, the filter ring belt is configured to be antistatic. This can be achieved using an antistatic coating on the filter ring belt, for example, with carbon. However, all or part of the filaments can also be made of an antistatic material and woven into the filter ring belt.

[0019] Particularly advantageously, the imaginary surface located at the turning point of the transverse filaments is spaced apart from the turning point of the longitudinal filaments, allowing the thinner longitudinal filaments to be arranged at a certain interval between these surfaces. This creates a structure on the surface of the filter belt that is particularly conducive to fiber movement during the compression of the fiber belt. Attached Figure Description

[0020] Further advantages of the present invention are described below in the embodiments.

[0021] Figure 1 This is a side view of the drafting device of a spinning machine with a compression mechanism.

[0022] Figure 2 This is a top view of a compression device with a filter belt.

[0023] Figure 3 This is a magnified view of the fabric of the filter ring belt.

[0024] Figure 4a shows a cross-section of the fabric of the filter ring belt in the circumferential direction of the filter ring belt, and

[0025] Figure 4b is a cross-section of the fabric of the filter ring belt in the transverse direction to the circumference of the filter ring belt. Detailed Implementation

[0026] In the following description of the embodiments, the same reference numerals are used for features that are the same and / or at least similar in technical solution and / or working principle. Unless otherwise stated, the technical solution and / or working principle of these features are equivalent to the technical solution and working principle of the features described above.

[0027] Figure 1This is a schematic side view of a cross-section of the drafting device 1 of a spinning machine, particularly a ring spinning machine with a compression device 2. The drafting device 1 includes a feed roller pair 3, a twisting roller pair 4, and an output roller pair 5. Each of the roller pairs 3, 4, and 5 is formed by an upper roller and a lower roller or lower roll. The two rollers in each roller pair 3, 4, and 5 press against each other, forming clamping points K1, K2, and K3 at their contact points for the fiber assembly 6 entering the drafting device 1, respectively. The first clamping point K1 is formed by the feed roller pair 3, the second clamping point K2 by the twisting roller pair 4, and the third clamping point K3 by the output roller pair 5. The thread clamping point K4 is formed by a compression roller 7 pressing against a suction tube 8. The fiber assembly 6 is drafted based on the different rotational speeds of the roller pairs 3, 4, and 5. The fiber assembly 6 is conveyed through the drafting device 1 while being drafted. After leaving the stretching device 1, the stretched fiber belt 1 reaches the compression device 2, where the fiber assembly is compressed.

[0028] The compression device 2 has a suction slit 9 on the suction tube 8 between the clamping point K3 and the line clamping point K4, which gathers and compresses the fibers of the fiber assembly 6 at the edge of the suction slit. The drawn fiber assembly 6 is transported along the transport direction T to above the suction tube 8 by means of a filter ring belt 10, which surrounds the suction tube 8 and the deflector rod 11 in the circumferential direction U. The filter ring belt 10 is driven by a pressure roller 7. The pressure roller 7 rotates via the upper roller of the output roller pair 5 by means of an element not shown. The negative pressure present in the suction tube 8 and sucking the fiber assembly 6 through the suction slit 9 also acts through the breathable filter ring belt 10.

[0029] After the compression device 2, the fiber assembly 6 forming the thread 12 after the clamping point K4 reaches the guide wire 13 and is further guided to the spinning device (not shown).

[0030] To open the drafting device 1, the upper rollers of roller pairs 3, 4, and 5 can be lifted from the lower rollers, and the clamping roller 7 can be lifted. For this purpose, and to close the drafting device 1 again, the load arm 14, which is fastened to the upper rollers and the clamping roller 7 in a known manner, moves about the rotation point D in the direction of arrow P.

[0031] Figure 2 A top view of the compression device 2 with a filter ring belt 10 is shown. The fiber assembly 6, together with the rotating filter ring belt 10, is transported along the circumferential direction U of the filter ring belt or along the transport direction T of the fiber assembly 6 to above the suction pipe 8. The filter ring belt 10 lies flat on the suction pipe 8 and slides across it. Figure 1As shown, the filter belt 10 is driven by the driven compression roller 7. The fiber assembly 6 is sucked in the area of ​​the suction slit 9 and compressed at the edge of the suction slit 9, which is inclined relative to the transport direction T of the fiber assembly 6. For this purpose, the filter belt 10 is breathable, so that the negative pressure in the suction tube 8 can pass through the filter belt 10 and act on the fibers of the fiber assembly 6. In particular, the sliding contact of the filter belt 10 on the suction tube 8 will cause wear to form on the bottom side of the filter belt 10.

[0032] Figure 3 A magnified partial view of the plain weave fabric of the filter belt 10 of the present invention is shown. The fabric of the filter belt 10 has adjacent longitudinal yarns 15 and adjacent transverse yarns 16. Fibers 17 of a fiber assembly 6 laid flat on the filter belt 10 are schematically shown. The fiber assembly 6 is correspondingly laid flat on the filter belt 10 along the transport direction T of the fiber assembly 6. The fibers 17 are arranged longitudinally in the circumferential direction U of the filter belt 10.

[0033] The longitudinal filaments 15 and transverse filaments 16 are spaced apart from each other, allowing air to pass through the mesh formed in the filter ring belt 10. The spacing AL between the longitudinal filaments 15 is greater than the spacing AQ between the transverse filaments 16. The spacing AL can be, for example, about 400 μm, and the spacing AQ can be, for example, about 100 μm. The resulting screen surface 18 has rectangular meshes between the longitudinal filaments 15 and the transverse filaments 16, with dimensions equal to the spacing AL and AQ. Due to the smaller mesh width, less fiber loss occurs in the circumferential direction U or the transport direction T. The larger mesh width transverse to the fiber direction allows for a larger volumetric airflow rate and good compression of the fiber assembly 6. The free surface between the longitudinal filaments 15 and the transverse filaments 16, i.e., the screen surface 18, particularly occupies 20% to 60% of the entire filter ring belt surface, preferably 30% to 50%.

[0034] The longitudinal filaments 15 have a diameter DL, which is much smaller than the diameter DQ of the transverse filaments 16. The transverse filaments 16 preferably have a diameter DQ, which is 10% to 80% larger than the diameter DL of the longitudinal filaments 15. Therefore, the diameter DQ of the transverse filaments 16 can be, for example, about 150 μm, and the diameter DL of the longitudinal filaments 15 can be, for example, about 100 μm. Due to this diameter difference, the flattened structure of the filter ring belt 10 on the suction pipe 8 is achieved on the surface of the transverse filaments 16. Therefore, wear occurs first on the transverse filaments 16. Only when these transverse filaments are worn to the same height as the longitudinal filaments 15 will the longitudinal filaments 15 be worn as well.

[0035] Figure 4a shows a cross-section of the fabric of the filter belt 10 in the transport direction T of the fiber assembly 6 or in the circumferential direction U of the filter belt 10. The fibers 17 of the fiber assembly 6 are correspondingly placed on the filter belt 10 along the drawing plane. It can also be seen from this figure that the diameter DL of the warp 15 is smaller than the diameter DQ of the cross filament 16. Correspondingly, the imaginary surface F located at the turning point WQ of the cross filament 16 is spaced apart from the turning point WL of the warp filament 15. Correspondingly, the bottom side of the filter belt 10 is generally laid flat on the suction tube 8 at the turning point WQ of the cross filament 16. On the top side of the filter belt 10, the pressure roller 7 is also generally close to the turning point WQ of the cross filament 16. Wear occurs primarily on the cross filament 16 because the thinner and less serrated warp filament 15 is spaced apart from these surfaces F by a distance a, and therefore generally does not come into contact with the suction tube 8 and the pressure roller 7. Therefore, the distance between turning points WL and AWL is less than the distance between turning points WQ and AWQ. Turning point WL lies between the two surfaces F.

[0036] Figure 4b shows a cross-section of the fabric of the filter belt 10 transverse to the transport direction T of the fiber assembly 6 or transverse to the circumferential direction U of the filter belt 10. Therefore, the fibers 17 of the fiber assembly 6 are placed on the filter belt 10 perpendicular to the drawing plane. It can also be seen here, as in Figure 4a, that the imaginary surface F located at the turning point WQ is spaced a distance a from the turning point WL of the warp 15. Thus, the points of action for the filter belt 10 to slide on the suction tube 8 and for driving by the pressure roller 7 are formed primarily on the thicker warp 16. The thinner warp 15 is spaced a distance a from the corresponding surface F on each side of the filter belt 10. Therefore, the thinner warp 15 is protected by the thicker warp 16, as the warp 15 is arranged in the fabric of the filter belt 10 in a manner not exposed to the warp 16.

[0037] As can also be seen from Figures 4a and 4b, the longitudinal filaments are less sinuous than the transverse filaments. Depending on the specific implementation, they may even be largely sinuous. In this case, the longitudinal filaments extend completely or at least approximately straight.

[0038] This invention is not limited to the embodiments shown and described. In particular, a thickness and spacing ratio different from the shown ratio of the thickness of the longitudinal filaments 15 to the spacing of the transverse filaments 16 can be used. Similarly, more or fewer longitudinal filaments 15 can be incorporated compared to the embodiments described. Although the diameters of the longitudinal filaments 15 and the transverse filaments 16 are different, within the scope of this invention, the value of the spacing a can still be reduced to "0". This can be achieved, for example, by incorporating more longitudinal filaments 15.

[0039] Modifications can also be made within the scope of the claims, for example, by combining features that appear in different embodiments.

[0040] Appendix Label Table

[0041] 1. Drafting device

[0042] 2. Compression device

[0043] 3 Feed roller pair

[0044] 4. Twisting rollers

[0045] 5 Output Roller Pair

[0046] 6. Fiber aggregates

[0047] 7. Press the roller

[0048] 8. Suction tube

[0049] 9. Suction opening

[0050] 10 sieve filter rings

[0051] 11 Deflection rod

[0052] 12 lines

[0053] 13. Wire guide

[0054] 14 Loading Arm

[0055] 15 longitudinal threads

[0056] 16 horizontal lines

[0057] 17 Fibers

[0058] 18 sieve surface

[0059] a Spacing

[0060] AQ cross-thread spacing

[0061] AL (Longitudinal filament spacing)

[0062] AWL spacing

[0063] AWQ Spacing

[0064] DQ cross wire diameter

[0065] DL longitudinal wire diameter

[0066] D Rotation point

[0067] F surface

[0068] K1 clamping point

[0069] K2 clamping point

[0070] K3 clamping point

[0071] K4 line clamping point

[0072] L - Direction of movement

[0073] P arrow direction

[0074] WQ Crosshair Turning Point

[0075] WL longitudinal turning point

Claims

1. A filter belt with an annular circumference for transporting a fiber assembly (6) to be compressed above a suction slit (9) of a compression device (2) of a spinning machine, the filter belt having a plurality of adjacent longitudinal filaments (15) in the circumferential direction (U) and a plurality of adjacent transverse filaments (16) in the transverse direction to the circumferential direction (U), wherein there are spacings (AL, AQ) between the adjacent longitudinal filaments (15) and the adjacent transverse filaments (16), the spacings (AL, AQ) forming free surfaces, thereby allowing the filter belt (10) to be permeable to air, characterized in that, Compared to the adjacent transverse filament (16), the adjacent longitudinal filament (15) has a thinner cross section, and both the longitudinal filament (15) and the transverse filament (16) are long filaments; the longitudinal filament (15) is arranged inside the surface (F) formed by the turning point (WQ) of the transverse filament (16).

2. The filter belt according to claim 1, characterized in that, The longitudinal wire (15) is less wavy than the transverse wire (16), so that the spacing (AWL) of the turning points (WL) of the longitudinal wire (15) is less than the spacing (AWQ) of the turning points (WQ) of the transverse wire (16).

3. The filter belt according to claim 1, characterized in that, The longitudinal filament (15) extends in a generally straight line.

4. The filter belt according to claim 1, characterized in that, The spacing (AL) between adjacent longitudinal threads (15) is greater than the spacing (AQ) between adjacent transverse threads (16).

5. The filter belt according to claim 1, characterized in that, The free surface between the longitudinal filament (15) and the transverse filament (16) accounts for 20% to 60% of the surface of the filter ring belt.

6. The filter belt according to claim 1, characterized in that, The free surface between the longitudinal filament (15) and the transverse filament (16) accounts for 30% to 50% of the surface of the filter ring belt.

7. The filter belt according to claim 1, characterized in that, The diameter (DQ) of the transverse wire (16) is 10% to 80% larger than the diameter (DL) of the longitudinal wire (15).

8. The filter belt according to claim 1, characterized in that, The filter ring (10) has a plain weave or a twill weave.

9. The filter belt according to claim 1, characterized in that, The filter ring (10) is configured to be antistatic.

10. The filter belt according to claim 2, characterized in that, The imaginary surface (F) located at the turning point (WQ) of the transverse wire (16) is spaced apart from the turning point (WL) of the longitudinal wire (15), thereby making the thinner longitudinal wire (15) spaced apart from the imaginary surface (F) by a distance (a).

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