CLOTHING WIRE AND METHOD FOR PRODUCING STAPLE FIBRE NONWOVENS

Abstract

A clothing wire for mounting on a clothing roll of a carding machine has a base section (1) and a blade section (4). A gradient dh/db of the height (h) as a function of the width (b) of at least a first section (10) of at least one blade-section side face (5, 6) is greater than the gradient dh/db of a second section (11) of the at least one blade-section side face (5, 6). The second section (11) is closer to the base section (1) than the first section (10). The sign of the gradients dh/db is the same. In a region which extends to a vertical distance of at most of the overall height of the blade section beneath the at least one second portion (11), there no protrusions or indentations cause a gradient sign change on the at least one blade-section side face (5, 6).

Claims

1. Sawtooth wire for mounting on a carding roll of a carding machine, the sawtooth wire comprising: a) a foot segment (1) with a base area (2) to be supported on a clothing roller, the base area (2) extending in a longitudinal direction (Z) and a lateral direction (B) of the sawtooth wire, b) a blade segment (4) extending in a height direction (H), which is perpendicular to the base area (2), and having height values, as measured from the base area (2), increasing in a direction of a side of the blade segment (4) facing away from the foot segment (1) up to a maximum height (hmax) of the blade segment (4), and c) the blade segment (4) being confined in the lateral direction (B) by a first (5) and a second (6) blade-segment lateral surface, wherein: d) an absolute value of a gradient dh/db of height (h) as a function of breadth (b) at least of a first portion (10) at least of one of the first and the second blade-segment lateral surface (5, 6) is greater than a absolute value of a gradient dh/db of at least a second portion (11) of the at least of one of the first and the second blade-segment lateral surface (5, 6), wherein height values of the at least one second portion being smaller than height values of the at least one first portion (10) and the gradient dh/db of the at least one first portion (10) and of the at least one second (11) portion having a same sign, e) gradients dh/db of portions on a same blade-segment lateral surface (5, 6) whose height values are in a range extending between a smallest height value (h22) of the at least one second portion (11) and a further height value (h3) which is located, at most, at of an overall height (Hmax) of the blade segment (4) below the smallest height value (h22) of the at least one second portion (11), have the same sign as the gradients dh/db of the at least one first portion (10) and of the at least one second (11) portion, and f) a smallest height value (h12) of the at least one first portion (10) being located in an area which is 50% to 98% of the overall height (Hmax) above a minimum height (hmin) of the blade segment (4).

2. Sawtooth wire according to claim 1, wherein the gradients dh/db of the portions on the same blade-segment lateral surface (5, 6) whose height values are in the range extending between the smallest height value (h22) of the at least one second portion (11) and the further height value (h3) which is, at the most, of the overall height (Hmax) of the blade segment below the smallest height value (h22) of the at least one second portion (11), have the same sign as the gradients dh/db of the at least one first portion (10) and of the at least one second (11) portion.

3. Sawtooth wire according to claim 1, wherein the gradients dh/db of the portions on the same blade-segment side (5, 6) whose height values are smaller than the smallest height value (h22) of the at least one second portion (11) have the same sign as the gradients dh/db of the at least one first (10) and of the at least one second (11) portion.

4. Sawtooth wire according to claim 1, wherein the smallest height value (h12) of the at least one first portion (10) borders on a largest height value (h21) of the at least one second portion (11).

5. Sawtooth wire according to claim 1, comprising: an exterior surface (7), which limits the sawtooth wire in the height direction (H) on a side facing away from the foot segment (1) and which also extends in the height direction (H) and in so doing defines at least one tooth (8) of the sawtooth wire, and wherein the at least one tooth (8) includes the at least one first portion (10) and the at least one second (11) portion.

6. Sawtooth wire according to claim 1, wherein the at least one first portion (10) and the at least one second portion (11) are located at a point (z) in the sawtooth wire's longitudinal direction (Z).

7. Sawtooth wire according to claim 1, wherein surface portions of the at least one blade-segment lateral surface (5, 6), which extend curvilinearly in a plane defined by the lateral direction (B) and the height direction (H).

8. Sawtooth wire according to claim 1, comprising a first straight surface portion (33) and a second (34) straight surface portion of the at least one blade-segment lateral surface (5, 6), which extend straight in a plane defined by the lateral direction (B) and the height direction (H), which follow each other in succession in the height direction (H), and which define an angle (3) in the plane defined by the lateral direction (B) and the height direction (H).

9. Sawtooth wire according to claim 1, wherein at most four straight surface portions follow each other in succession in the height direction (H).

10. Sawtooth wire according to claim 1, wherein a highest straight surface portion (33) and a surface portion (34) adjacent thereto border on each other in a height region located between 5/10 and 9/10 of the overall height (Hmax) above the minimum height (hmin) of the blade segment (4).

11. Sawtooth wire according to claim 1, comprising at least a first portion (10) of the at least one blade-segment lateral surface (5, 6), said first portion making an angle of less than 5 with a line perpendicular (19) dropped to the base area (2) of the foot.

12. Sawtooth wire according to claim 11, wherein the at least a first portion (10) of the at least one blade-segment lateral surface (5, 6) runs parallel to the line perpendicular (19) to the base area of the foot.

13. Sawtooth wire according to claim 1, comprising at least one first portion (10) of the first blade-segment lateral surface (5), said first portion running parallel to a portion, located at a same height, of the second blade-segment lateral surface (6).

14. Sawtooth wire according to claim 11, comprising at least a second portion (11) of the at least one blade-segment lateral surface (5, 6), said second portion making an angle (2), which is greater than 6, with the line perpendicular (19) to the base area of the foot.

15. Method of manufacturing fibre fleeces, the method comprising: processing cotton and/or synthetic fibres using a sawtooth wire comprising: a) a foot segment (1) with a base area (2) to be supported on a clothing roller, the base area (2) extending in a longitudinal direction (Z) and a lateral direction (B) of the sawtooth wire, b) a blade segment (4) extending in a height direction (H), which is perpendicular to the base area (2), and having height values, as measured from the base area (2), increasing in a direction of a side of the blade segment (4) facing away from the foot segment (1) up to a maximum height (hmax) of the blade segment (4), and c) the blade segment (4) being confined in the lateral direction (B) by a first (5) and a second (6) blade-segment lateral surface, wherein: d) an absolute value of a gradient dh/db of height (h) as a function of breadth (b) at least of a first portion (10) at least of one of the first and the second blade-segment lateral surface (5, 6) is greater than a absolute value of a gradient dh/db of at least a second portion (11) of the at least of one of the first and the second blade-segment lateral surface (5, 6), wherein height values of the at least one second portion being smaller than height values of the at least one first portion (10) and the gradient dh/db of the at least one first portion (10) and of the at least one second (11) portion having a same sign, e) gradients dh/db of portions on a same blade-segment lateral surface (5, 6) whose height values are in a range extending between a smallest height value (h22) of the at least one second portion (11) and a further height value (h3) which is located, at most, at of an overall height (Hmax) of the blade segment (4) below the smallest height value (h22) of the at least one second portion (11), have the same sign as the gradients dh/db of the at least one first portion (10) and of the at least one second (11) portion, and f) a smallest height value (h12) of the at least one first portion (11) being located in an area which is 50% to 98% of the overall height (Hmax) above a minimum height (hmin) of the blade segment (4).

16. Method according to claim 15, wherein the processing the cotton and/or synthetic fibres using the sawtooth wire comprises processing the cotton and/or synthetic fibres using a sawtooth wire having the overall height (Hmax) of less than 4.0 mm.

17. Method according to claim 15, wherein the processing the cotton and/or synthetic fibres using the sawtooth wire comprises processing the cotton and/or synthetic fibres using a sawtooth wire having a highest straight surface portion (33) and a second surface portion (34) bordering the highest straight surface portion (33) in a height region which, in the height direction (H), is located between 5/100 and 2/10 mm below the maximum height (hmax).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0068] The invention is explained in more detail below on the basis of three embodiments. The drawing in

[0069] FIG. 1: is a perspective view of a sawtooth wire,

[0070] FIG. 2: shows a cross section of a sawtooth wire having a blade-segment lateral surface with two planar surface portions; for reasons of clarity, the wire is shown enlarged in the lateral direction.

[0071] FIG. 3: shows a profile of a sawtooth wire having a blade-segment lateral surface with two planar surface portions;

[0072] FIG. 4: shows a cross section of a sawtooth wire having a blade-segment lateral surface with four planar surface portions; for reasons of clarity, the wire is shown enlarged in the lateral direction.

[0073] FIG. 5: shows a profile of a sawtooth wire having a blade-segment lateral surface with four planar surface portions;

[0074] FIG. 6: shows a cross section of a sawtooth wire the blade-segment lateral surface of which is a concave curve; for reasons of clarity, the wire is shown enlarged in the lateral direction.

[0075] FIG. 7: shows a profile of a sawtooth wire with a concave blade-segment lateral surface;

[0076] FIG. 8: shows the determination of contour gradients in the plane extending in the height direction H and lateral direction B;

[0077] FIG. 9: shows a blade segment and choice of position for the first and second portions on the blade segment;

[0078] FIG. 10: shows an alternative shape for the foot segment;

[0079] FIG. 11: shows a first shape for the second blade-segment lateral surface;

[0080] FIG. 12: shows a second shape for the second blade-segment lateral surface;

[0081] FIG. 13: shows a further cross section of a sawtooth wire.

DETAILED DESCRIPTION

[0082] The section of sawtooth wire shown in FIG. 1 consists of a foot segment 1 featuring a base area 2 and two lateral surfaces 3, and a blade segment 4 which adjoins the foot segment 1 and has a first blade-segment lateral surface 5 and a second blade-segment lateral surface 6. On the side further away from the foot segment 1 (facing upwards), the blade segment 4 is delimited by an exterior surface 7, which undulates along a serrated path in such a manner as to form teeth 8.

[0083] The sawtooth wire runs in the longitudinal direction Z; its height extends in the height direction H and its breadth in the lateral direction B (B is perpendicular to both Z and H).

[0084] The height value at which the blade segment 4 has its greatest reach in the height direction H is referred to as the blade segment's maximum height h.sub.max. The height value at which the blade segment begins (at the bottom thereof) is referred to as the minimum height h.sub.min. The span (in the height direction) between the minimum height h.sub.min and the maximum height h.sub.max is the overall height H.sub.max of the blade segment.

[0085] The second blade-section lateral surface 6 extends (apart from manufacturing tolerances) in a plane spanned by the longitudinal direction Z and the height direction H.

[0086] The first blade-segment lateral surface 5 is made up of a first portion 10 located higher up on the blade segment 4 (further away from the foot segment 1) and a second portion 11 located lower down on the blade segment (nearer the foot segment 1). As already explained earlier, the comparatively flat, rounded transition area 9 between the foot segment 1 and the blade segment 4 is not part of the blade segment 4. The first portion 10 is practically parallel to the plane defined by the longitudinal direction Z and the height direction H (accordingly, it is also parallel to the second blade-segment lateral surface 6), i.e. its gradient is infinitely large. The first portion 10 may alternatively enclose a small angle not exceeding 2 with the height direction H (i.e. dh/db assumes a finite value) and, except for manufacturing tolerances, run parallel to the longitudinal direction Z.

[0087] The second portion 11 is also parallel to the longitudinal direction Z (except for manufacturing tolerances) but, compared with the first portion 10, encloses a substantially larger angle of 8 to 12 with the height direction H. In other words, the first portion 10 is steeper than the second portion 11. A steep run generally means that dh/db is large. For a flat run, dh/db is accordingly small.

[0088] On account of the particular geometry of the blade-segment 4, its breadth B initially increases very slowly (or not at all) from the top downwards, e.g. starting from one of the tooth tips 12 (technically speaking, the tip is a short edge), as its height decreases (i.e. towards the foot segment). At the transition 13, at which the first portion 10 merges into the second portion 11, the breadth of the blade segment 4 then increases faster (or commences to increase) with decreasing height. The sawtooth wire's property of featuring a blade segment 4 the breadth of which, starting from the top, initially increases more slowly and then, towards the bottom, increases more quickly, is essential to the invention and is shown by a multiplicity of advantageous embodiments thereof. Of course, this applies only to those areas of the sawtooth wire in which the material of the original profile is still there, i.e. in which no material was punched out.

[0089] In FIG. 2 the cross section of the sawtooth wire shown in FIG. 1 is illustrated, and in FIG. 3 the associated starting profile (corresponding to the sawtooth wire without teeth). The sectional plane (of the cross section) extends in the lateral direction B and the height direction H. In FIG. 2as in FIGS. 4 and 6the lateral direction B is shown enlarged (i.e. the overall breadth B.sub.max of the sawtooth wire is shown enlarged compared to the overall height H.sub.max,) in order to enable the viewer to recognize the angles and gradients.

[0090] As is apparent from FIG. 2, the first portion 10 (in the respective sectional plane) is delimited by the end points 14 and 15 and the second portion 11 by the end points 15 and 16. The first secant 17, which runs along the first portion 10 (i.e. through the end points 14, 15 of the first portion 10) in the sectional plane defined by the lateral direction B and the height direction H, has a steeper gradient than the second secant 18, which runs in the same plane and along the second portion 11 (through the end points 15, 16 of the second portion).

[0091] FIG. 4 shows the cross section (and FIG. 5 the associated profile) of a sawtooth wire the first blade-segment lateral surface 5 of which is made up of four planar surface portions following each other in succession in the height direction H. The uppermost planar surface portion (furthest from the foot segment 1), which (in this sectional plane) is delimited by the end points 20 (with the height value h.sub.11) and 21 (with the height value h.sub.12), has been selected here as the first portion 10. The second uppermost planar surface portion, which is delimited by the end points 23 (with the height value h.sub.21) and 24 (with the height value h.sub.22) has been selected as the second portion 11. The first secant 22 runs through the end points 20 and 21, the second secant 25 through the end points 23 and 24. Both secants 22, 25 run in the plane defined by the lateral direction B and the height direction H. Here too, the secant 22 has a steeper gradient than the secant 25, i.e. the secant 22 encloses a smaller angle 1 with the perpendicular 19 dropped to the base area 2 of the foot segment than does the secant 25 (angle 2).

[0092] Beneath the end point 24, with the height value h.sub.22 of the at least one second portion, is the further height value h.sub.3. The further height value h.sub.3 is located (at a distance in the height direction H) approximately of the overall height H.sub.max beneath the lower height value h.sub.22 of the at least one second portion. No change in the sign of the gradient dh/db is allowed in the area between these two height values, i.e. no elevations or indentations are allowed in this area.

[0093] FIG. 6 shows the cross section (and FIG. 7 the associated profile) of a sawtooth wire the first blade-segment lateral surface 5 of which (seen from the outside) is a concave curve (with no kinks). In FIG. 6as before in FIGS. 2 and 4the lateral direction B is once again shown enlarged so that the viewer is able to recognize different angles between the perpendicular 19 and the tangents 27 and 30. It remains to be mentioned that in FIGS. 2, 4 and 6 the points 14, 15, 16, 20, 21, 23, 24, 26 and 29 are represented by horizontal strokes, which intersect the contour of the sawtooth wire 1. The respective point lies at the intersection between the horizontal stroke and the contour of the sawtooth wire 1.

[0094] An infinitesimally small surface portion 26 in the height direction H (punctiform relative to the selected sectional plane) has been selected as the first portion 10. Here, the tangent 27 to the first blade-segment lateral surface 5 at the surface portion/point 26 takes the place of the otherwise customary secant running along a planar portion (in the plane defined by the lateral and height directions). The second portion 11 is formed analogously by the point 29, with the tangent 30 in place of the secant along a planar portion. Here too (as with the respective secants) the gradients of the tangents correspond in each case to the derivative dh/db at the respective point. As in the two preceding examples, the tangent 27 has a steeper gradient dh/db than the tangent 30, i.e. the tangent 27 encloses a smaller angle 1 with the perpendicular 19 dropped to the base area 2 of the foot segment than does the tangent 30 (angle 2).

[0095] FIG. 8 shows the contours of two first blade-segment lateral surfaces 5 in the plane defined by the height direction H and the lateral direction B. The one first blade-segment lateral surface 5 running in the respective plane is entirely curved 31, the other first blade-segment lateral surface 32 is made up of two planar surface portions 33, 34. The lateral direction B is again shown in enlarged form.

[0096] In the case of the blade-segment lateral surface 32, which comprises two planar surface portions, the first portion 10 may be selected as the surface portion 33, which extends between the points with the coordinates (b.sub.11, h.sub.11) and (b.sub.12, h.sub.12), and the second portion 11 as the surface portion 34, which extends between the points with the coordinates (b.sub.21, h.sub.21) and (b.sub.22, h.sub.22). The gradient of the secant through the end points of the first portion 10 is then (h.sub.12-h.sub.11)/(b.sub.12-b.sub.11), the gradient of the secant through the end points of the second portion 11 is (h.sub.22-h.sub.21)/(b.sub.22-b.sub.21).

[0097] For the blade-segment lateral surface 31, which is entirely curved, the first portion 10 and the second portion 11 are selected (at least in the viewing plane) to be infinitesimally small (i.e. punctiform). The gradient of the first portion 10 equals the derivative dh/dh at the point b.sub.11 (or at the point b.sub.12, since the two end points of the infinitesimally small portion 10 coincide), the gradient of the second portion 11 equals the derivative dh/db at the point b.sub.21 (or b.sub.22).

[0098] FIG. 9 shows a tooth 8 whose height corresponds to the overall height H.sub.max of the blade segment 4, i.e. the overall height of the tooth 8 equals the overall height H.sub.max (=h.sub.maxh.sub.min) of the blade segment 4.

[0099] The tooth has, in the area of the tooth tip 12, a first planar surface portion 35, which is steeper, and, further down, a second planar surface portion 36, which is flatter. The two surface portions 35, 36 border on each other at the partition line 37.

[0100] It is possible to select either a first portion 110b, which extends between the height values h11 and h12, and a second portion 111 (which extends between the height values h21 and h22), which have the same reach z1 in the longitudinal direction Z. Or it is possible to select a first portion 110a, which extends between the height values h11 and h12, and the second portion 111, the two portions 110a and 111 having different reaches z1, z2 in the longitudinal direction Z.

[0101] As is evident from FIG. 10, the foot segment 1 may be shaped such that adjacent wire sections interlock (linked configuration). The gradients of the side walls 38 of the foot segment are not subject matter of this application.

[0102] In FIGS. 11 and 12, embodiments of the second blade-segment lateral surface 6 are illustrated. The second blade-segment lateral surface 6 shown in FIG. 11 is approx. mirror-symmetric to the first blade-segment lateral surface 5. FIG. 12 shows a blade-segment lateral surface 6 which is slightly inclined relative to the height direction H.

[0103] FIG. 13 shows that the at least one blade-segment surface 5 of the sawtooth wire showing the feature essential to the invention may also lie on the other side of the sawtooth wire 1.

LIST OF REFERENCE NUMERALS

[0104] 1 Foot segment [0105] 2 Base area of foot segment [0106] 3 Lateral surface of foot segment [0107] 4 Blade segment [0108] 5 First blade-segment lateral surface [0109] 6 Second blade-surface lateral surface [0110] 7 Exterior surface of blade segment [0111] 8 Tooth [0112] 9 Rounded transition area between blade segment and foot segment [0113] 10 First portion [0114] 11 Second portion [0115] 12 Tooth tip [0116] 13 Transition between first and second portions [0117] 14 First end point [0118] 15 Second end point [0119] 16 Third end point [0120] 17 First secant [0121] 18 Second secant [0122] 19 Perpendicular dropped to the base of the foot [0123] 20 First end point [0124] 21 Second end point [0125] 22 First secant [0126] 23 Third end point [0127] 24 Fourth endpoint [0128] 25 Second secant [0129] 26 Infinitesimally small first surface portion/first point [0130] 27 Tangent to the first surface portion [0131] 29 Infinitesimally small second surface portion/second point [0132] 30 Tangent to the second surface portion [0133] 31 Curved contour of the blade-segment lateral surface [0134] 32 Contour of the blade-segment lateral surface, which is made up of two planar surface portions [0135] 33 First planar surface portion [0136] 34 Second planar surface portion [0137] 35 Steeper planar surface portion [0138] 36 Flatter planar surface portion [0139] 37 Dividing line between the steeper and the flatter planar surface portions [0140] 38 Side walls of the foot [0141] 110a First portion [0142] 110b First portion (alternative) [0143] 111 Second portion [0144] Z Longitudinal direction [0145] B Lateral direction [0146] H Height direction [0147] B.sub.max Overall breadth of blade segment [0148] b.sub.11 Upper lateral value of first portion [0149] b.sub.12 Lower lateral value of first portion [0150] b.sub.11 Upper lateral value of first portion (alternative) [0151] b.sub.12 Lower lateral value of first portion (alternative) [0152] b.sub.21 Upper lateral value of second portion [0153] b.sub.22 Lower lateral value of second portion [0154] H.sub.max Overall height of blade segment [0155] h.sub.max Maximum height of blade segment [0156] h.sub.min Minimum height of blade segment [0157] h.sub.11 Upper height value of first portion [0158] h.sub.12 Lower height value of first portion [0159] h.sub.11 Upper height value of first portion (alternative) [0160] h.sub.12 Lower height value of first portion (alternative) [0161] h.sub.21 Upper height value of second portion [0162] h.sub.22 Lower height value of second portion [0163] h.sub.3 Further height value [0164] z.sub.1 First longitudinal reach value [0165] z.sub.2 Second longitudinal reach value [0166] 1 Angle between the first portion and the perpendicular dropped to the base [0167] 2 Angle between the second portion and the perpendicular dropped to the base [0168] 3 Angle between the first and second portions