Abstract
A sheet-forming wire with a lower fabric layer formed from a multiplicity of identically constructed lower weave repeats, each of which contains longitudinal threads extending in the lower fabric layer, and lower cross threads, with the lower cross threads extend only in the lower fabric layer. The lower cross threads are tied into the lower fabric layer in each case by exactly two longitudinal threads extending in the lower fabric layer, in that each particular lower cross thread is run under by a first longitudinal thread at a first tying-in point (x) and is run under by a second longitudinal thread at a second tying-in point (x). The lower cross threads form first lower cross threads (I) and second lower cross threads (II). The first lower cross threads form a shorter float on the running side than the second lower cross threads.
Claims
1. A paper machine screen formed as a multi-layer fabric having an upper fabric layer and a lower fabric layer which are connected to each other by means of binding threads, wherein the lower fabric layer is formed by a plurality of uniformly structured lower weave repeats, each of which comprising: longitudinal threads extending in the lower fabric layer and lower transverse threads extending exclusively in the lower fabric layer and being interwoven with the longitudinal threads that extend in the lower fabric layer, wherein in the respective lower weave repeat the lower transverse threads are each bound into the lower fabric layer by exactly two longitudinal threads that extend in the lower fabric layer as a first longitudinal thread extends under the respective lower transverse thread at a first binding position and a second longitudinal thread extends under the respective lower transverse thread at a second binding position, and wherein in the respective lower weave repeat the lower transverse threads are bound into the lower fabric layer differently, thereby forming first lower transverse threads and second lower transverse threads, wherein at the first lower transverse threads a shortest distance in transverse direction between the first and the second binding position is larger than at the second lower transverse threads so that the first lower transverse threads (I) form a shorter float on the running side than the second lower transverse threads.
2. The paper machine screen according to claim 1, wherein the larger shortest distance in transverse direction at the first lower transverse threads is achieved by the fact that at the first lower transverse threads between the first and the second binding position at least one longitudinal thread more, extending in the lower fabric layer and extending over the lower transverse thread, is arranged than at the second lower transverse threads, and/or wherein at the first lower transverse threads the shortest distance in transverse directionexpressed by longitudinal threads positioned therebetween, extending in the lower fabric layer and extending over the lower transverse threadis one longitudinal thread or two longitudinal threads, and wherein at the second lower transverse threads the shortest distanceexpressed by longitudinal threads positioned therebetween, extending in the lower fabric layer and extending over the lower transverse threadis zero longitudinal threads or one longitudinal thread, and/or wherein in the lower weave repeat at the first lower transverse threads respectively exactly one longitudinal thread, extending in the lower fabric layer and extending over the lower transverse thread, is arranged between the first and the second binding position, and wherein in the lower weave repeat at the second lower transverse threads between the first and the second binding position no longitudinal thread, extending in the lower fabric layer and extending over the lower transverse thread, is arranged respectively so that both binding positions are located immediately adjacent to each other.
3. The paper machine screen according to claim 1, wherein the different shortest distance in transverse direction is achieved by the fact that the first lower transverse threads are introduced into the lower fabric layer with a course different from the second lower transverse threads with respect to the longitudinal threads extending in the lower fabric layer, wherein all of the first lower transverse threads in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions in transverse direction varies, and wherein all of the second lower transverse threads in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions in transverse direction varies.
4. The paper machine screen according to claim 1, wherein in the lower weave repeat the binding positions of a respective first lower transverse thread are arranged offset in a transverse direction to the binding positions of the two first lower transverse threads adjacently arranged in longitudinal direction, and/or wherein in the lower weave repeat the binding positions of a respective second lower transverse thread are arranged offset in a transverse direction to the binding positions of the two second lower transverse threads adjacently arranged in longitudinal direction, and/or wherein in the lower weave repeat the binding positions of two first lower transverse threads, arranged directly next to each other in longitudinal direction, are arranged offset in a transverse direction always by the same amount of longitudinal threads extending in the lower fabric layer and in the same direction, and/or wherein in the lower weave repeat the binding positions of two second lower transverse threads, arranged next to each other in longitudinal direction, are arranged offset in a transverse direction always by the same amount of longitudinal threads extending in the lower fabric layer and in the same direction.
5. The paper machine screen according to claim 1, wherein the ratio of first lower transverse threads to second lower transverse threads in the lower weave repeat is 1:1 or 2:1 or 1:2.
6. The paper machine screen according to claim 1, wherein the first lower transverse threads have, relative to the second lower transverse threads, different thermosetting properties and/or wherein the first lower transverse threads have a cross-sectional shape and/or a diameter different from the second lower transverse threads and/or, wherein the first lower transverse threads are made of a material different from the material of the second lower transverse threads and/or wherein the first lower transverse threads and the second lower transverse threads are treated differently with influence on their thermosetting behavior.
7. The paper machine screen according to claim 1, formed as a synthetic fabric with at least the lower transverse threads being formed as synthetic threads.
8. The paper machine screen according to claim 7, wherein a respective of the lower transverse threads is made of polyamide or polyester.
9. The paper machine screen according to claim 1, formed as transverse thread-bound multi-layer fabric, in which the binding threads are formed from transverse threads, and/or wherein the binding threads are formed from transverse threads extending in the upper fabric layer and, on the one hand, contributing to forming the upper weave and, on the other hand, descending in sections into the lower fabric layer to extend under at least one of the longitudinal threads extending in the lower fabric layer and thereby bind the lower fabric layer to the upper fabric layer.
10. The paper machine screen according to claim 1, wherein the longitudinal threads extending in the lower fabric layer are formed as lower longitudinal threads extending exclusively in the lower fabric layer.
11. The paper machine screen according to claim 1, wherein the lower weave repeat comprises at least 8 longitudinal threads extending in the lower fabric layer, and/or wherein in the lower weave repeat the ratio of lower transverse threads to longitudinal threads extending in the lower fabric layer is 2:1, and/or wherein in the lower weave repeat, when seen in a longitudinal direction, always a transverse thread-binding to the upper fabric layer is provided between two lower transverse threads arranged immediately next to each other.
12. The paper machine screen according to claim 1, wherein the diameter of the lower transverse threads is larger than the diameter of the transverse threads extending in the upper fabric layer and/or larger than the diameter of the binding threads, and/or wherein the diameter of the lower transverse threads is larger than the diameter of the longitudinal threads extending in the lower fabric layer and/or wherein the lower transverse threads have the largest diameter in the total repeat of all threads.
13. The paper machine screen according to claim 1, wherein the upper fabric layer is formed from a plurality of uniformly structured upper weave repeats, each of which comprising: upper longitudinal threads extending exclusively in the upper fabric layer, upper transverse threads extending exclusively in the upper fabric layer and being interwoven with the upper longitudinal threads, thereby partially forming the upper weave, and binding transverse threads that, on the one hand, complete the upper weave and, on the other hand, descend in sections into the lower fabric layer to extend under at least one of the longitudinal threads extending in the lower fabric layer and thereby bind the lower fabric layer to the upper fabric layer.
14. The paper machine screen according to claim 13, wherein the fabric has a total repeat in which the ratio of upper longitudinal threads to lower longitudinal threads is 1:1.
15. The paper machine screen according to claim 1, wherein the upper fabric layer is formed with a plain weave.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Various exemplary embodiments will hereinafter be described in more detail with reference to the drawings. In the drawings in schematic representation:
(2) FIGS. 1 to 4 show a paper machine screen formed as a multi-layer fabric, especially sheet forming screen (or forming screen), according to a first embodiment (so-called 10-shaft configuration), wherein FIGS. 1a)-1d) represent various cross sections through the total repeat of the fabric, wherein the comparatively wide binding of the lower transverse thread 181 and the comparatively narrow binding of the lower transverse thread 182 can be seen, which results in a comparatively short float-length for the thread 181 and a comparatively long float-length for the thread 182.
(3) FIG. 2 shows the upper weave repeat in a plan view onto the top side of the upper fabric layer (=paper side of the screen), wherein the lower fabric layer has been cut off to improve depiction.
(4) FIG. 3 shows the lower weave repeat in a plan view onto the top side of the lower fabric layer (=side of the screen facing away from the running side) with the upper fabric layer having been cut off.
(5) FIG. 4 shows again the lower weave repeat, here in a bottom view onto the bottom side of the lower fabric layer or the running side of the screen, respectively.
(6) FIG. 5 showsin a representation corresponding to FIG. 4the lower weave repeat (especially its running side) of a paper machine screen, especially sheet forming screen (or forming screen), formed as a multi-layer fabric according to a second embodiment (so-called 8-shaft configuration).
(7) FIG. 6in a representation corresponding to FIG. 4shows the lower weave repeat (especially its running side) of a paper machine screen, especially sheet forming screen (or forming screen), formed as a multi-layer fabric according to a second embodiment (so-called 12-shaft configuration).
(8) In the FIGS. 2 to 6, threads extending from top to bottom are longitudinal threads and threads extending from left to right are transverse threads.
(9) In the FIGS. 1a) to 1d) the longitudinal threads are shown with a circular appearance (they extend perpendicularly to the paper plane and towards the viewer) and the transverse threads again extend from the left to the right.
(10) In the Figures identical or similar elements have identical references, where appropriate.
DETAILED DESCRIPTION OF THE DRAWINGS
(11) In the below detailed description reference is made to the accompanying drawings which form a part thereof and in which, by way of illustration, specific embodiments are being shown in which the invention may be practiced. In this regard directional terminology, such as top, bottom, front, back, leading, trailing, etc. is used with reference to the orientation of the Figure(s) being described. Because components of embodiments can be positioned in a number of different orientations, the directional terminology is used for purposes of illustration and is in no way limiting.
(12) It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. It is to be understood that features of the various exemplary embodiments described herein may be combined with each other, unless specifically indicated otherwise. The following detailed description is therefore not to be taken in a limiting sense with the scope of the present invention being defined by the appended claims.
(13) FIGS. 1 to 4 show a paper machine screen/sheet forming screen (below referred to as screen) formed as a multi-layer fabric, according to a first embodiment of the invention.
(14) As can be seen, for example, in FIGS. 1a) to 1d), the screen is formed as a multi-layer fabric with an upper fabric layer L1 and a lower fabric layer L2 that are connected to each other by means of binding threads (see transverse thread 123 in FIG. 1b) as well as the transverse thread 126 in FIG. 1d)). The paper side PS of the screen is formed by the upper fabric layer L1, whereas the running side LS of the screen is formed by the lower fabric layer L2.
(15) The lower fabric layer L2 is formed by a plurality of uniformly structured lower weave repeats (and consists, for example, of those) each of which containing longitudinal threads 111-120 extending in the lower fabric layer L2 and lower transverse threads 181-200 (e.g. the respective repeat consists of said threads) that extend exclusively in the lower fabric layer L2 and which are interwoven with the longitudinal threads 111-120 extending in the lower fabric layer.
(16) As shown in the Figures, the longitudinal threads extending in the lower fabric layer can, for example, be formed as lower longitudinal threads 111-120 extending exclusively in the lower fabric layer L2 and, for example, being interwoven with the lower transverse threads 181-200 thereby completely forming the lower weave. Hence reference is made below to lower longitudinal threads, even though the longitudinal threads 111-120 extending in the lower fabric layer can also be configured differently.
(17) As shown in FIG. 3, in the lower weave repeat the lower transverse threads 181-200 are each bound into the lower fabric layer by exactly two longitudinal threads 111-120 as a first longitudinal thread 111, 115, . . . extends under the respective lower transverse thread 181, 182, . . . at a first binding position x and a second longitudinal thread 133, 116, . . . extends under the respective lower transverse thread 181, 182, . . . at a second binding position x. For example, the longitudinal thread 111 extends under the lower transverse thread 181 at a first binding position x and the longitudinal thread 113 extends under the lower transverse thread 181 at a second binding position x (see also FIG. 1a)). Figuratively speaking thread 181 cannot fall downward out of the fabric/screen due to it being bound in twice. The longitudinal thread 115, however, extends under the lower transverse thread 182 at a first binding position x and the longitudinal thread 116 extends under the lower transverse thread 182 at a second binding position x (see also FIG. 1c)).
(18) As can be further seen in FIG. 3, in the respective lower weave repeat the lower transverse threads 181-200 are bound into the lower fabric layer differently, thereby forming first lower transverse threads I and second lower transverse threads II, wherein at the first lower transverse threads I a shortest distance (see also FIG. 4: distance A.sub.I) in transverse direction Q between the first and the second binding position x is larger than at the second lower transverse threads II (see FIG. 4: distance A.sub.II)
(19) As shown in FIG. 4, the different binding has the result that the first lower transverse threads I form on the running side LS a shorter float F.sub.I than the second lower transverse threads II whose float in FIG. 4 is designated F.sub.II. The float can, for example, be understood/referred to as the longest transverse thread-portion extending on the running side over an amount of successive lower longitudinal threads (i.e. between two binding positions). At the repeat in FIG. 4, counting/measuring is performed beyond the edge as, according to this embodiment, in transverse direction to the right and to the left respectively one further repeat is arranged directly next to the repeat shown. The float F.sub.1 is particularly easy to recognize for the thread 181 and the float F.sub.II is particularly easy to recognize for the thread 198. As shown, the float at the first lower transverse threads may, according to various embodiments, extend over seven lower longitudinal threads, whereas the float at the second lower transverse threads may extend over eight lower longitudinal threads.
(20) The different shortest distance as well as the different float-length resulting therefrom are also indicated in FIGS. 1a) and 1c). From those images it can also be seen that the different float or the different binding of the lower transverse threads, respectively, may initially/generally result in a different sagging of the lower transverse threads which, in turn, may cause a different projecting of the lower transverse threads on the running side.
(21) According to various embodiments, this situation is used, however, to at least partially compensate, e.g., a different behavior or different properties of the first and second lower transverse threads in the fabric, and/or to be able to accommodate different diameters and/or materials in the lower fabric. It is, for example, possible to have the transverse thread in FIG. 1c) that hangs further downward, shrunk more during a thermosetting of the screen than the transverse thread of FIG. 1a) that does not hang down that far.
(22) As can be seen in FIG. 3 (see also FIGS. 1a) and 1c)), the larger shortest distance A.sub.I in transverse direction Q at the first lower transverse threads I can, for example, be achieved by the fact that at the first lower transverse threads between the first and the second binding position x at least one longitudinal thread 111-120 more, extending over the lower transverse thread, is arranged than at the second lower transverse threads II, for example, exactly one longitudinal thread more or one additional longitudinal thread, respectively.
(23) As can further be seen in FIG. 3 (see also FIGS. 1a) and 1c)), at the first lower transverse threads I the shortest distance A.sub.I in transverse direction Qexpressed by lower longitudinal threads 111-120 positioned therebetween, extending over the lower transverse threadcan, for example be exactly one longitudinal thread, wherein at the second lower transverse threads II the shortest distance A.sub.IIexpressed by lower longitudinal threads 111-120 positioned therebetween, extending over the lower transverse threadis zero longitudinal threads.
(24) This means, in the lower weave repeat at the first lower transverse threads I between the first and the second binding position x, exactly one lower longitudinal thread 111-120, extending over the lower transverse thread, can be arranged, wherein in the lower weave repeat at the second lower transverse threads II between the first and the second binding position x no lower longitudinal thread 111-120, extending over the lower transverse thread, is arranged respectively so that both binding positions are located immediately adjacent to each other.
(25) As can further be seen in FIG. 3 (see also FIGS. 1a) and 1c)), the different shortest distance in transverse direction Q may, for example, be achieved by the fact that first lower transverse threads I are introduced/interwoven into the lower fabric layer with a course different from the second lower transverse threads II with respect to the lower longitudinal threads 111-120, wherein all of the first lower transverse threads I in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions x in transverse direction Q varies, and wherein all of the second lower transverse threads II in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions x in transverse direction Q varies.
(26) As can be seen in FIG. 3 (see also FIGS. 1a) and 1c)), the course of the first lower transverse threads I with respect to the lower longitudinal threads can, for example, be as follows: under seven successive longitudinal threads, over one longitudinal thread, under one longitudinal thread and over one longitudinal thread. The course of the second lower transverse threads II with respect to the lower longitudinal threads can, for example, be as follows: under eight successive longitudinal threads, and over two successive longitudinal threads. In this matter, counting is performed respectively in transverse direction beyond the edge of the lower repeat. The respective starting point or the binding positions, respectively, may, as mentioned before, vary in transverse direction; this does not change the above described basic course of the transverse threads with respect to the lower longitudinal threads.
(27) As can be seen in FIG. 3, in the lower weave repeat the binding positions x of a respective first lower transverse thread I may be, for example, arranged offset in a transverse direction to the binding positions of the two first lower transverse threads adjacently arranged in longitudinal direction L, for example offset to the binding positions of every other first lower transverse thread of the lower weave repeat. See, e.g. the first lower transverse thread 183 and the two first lower transverse threads 181 and 185 arranged adjacently in longitudinal direction L.
(28) As can also be seen in FIG. 3, in the lower weave repeat the binding positions x of a respective second lower transverse thread II may also be arranged offset in a transverse direction to the binding positions of the second lower transverse threads adjacently arranged in longitudinal direction L, for example offset to the binding positions of every other second lower transverse thread of the lower weave repeat. See, for example the second lower transverse thread 184 and the two second lower transverse threads 182 and 186 arranged adjacently in longitudinal direction L.
(29) As can be seen in FIG. 3, in the lower weave repeat the binding positions x of two first lower transverse threads I, arranged directly next to each other in longitudinal direction L, may be arranged offset in a transverse direction always by the same amount of longitudinal threads 111-120 extending in the lower fabric layer and in the same direction. The same holds true for the second lower transverse threads. In FIG. 3a pitch of three lower longitudinal threads to the left was selected by way of example for both the first lower transverse threads and the second lower transverse threads. See, e.g. the second lower transverse thread 182 and the second lower transverse thread 184, at which the binding positions x, arranged adjacently to each other, are respectively arranged offset to the left by three lower longitudinal threads 112-114 and 113-115, respectively. It is comprehensible, that a different pitch might be selected or that the binding positions may be arranged offset in an irregular manner.
(30) As can be seen in FIGS. 3 and 4, the ratio of first lower transverse threads I to second lower transverse threads II in the lower weave repeat may be, for example 1:1, e.g. at a directly alternating arrangement in longitudinal direction L, i.e. at a recurring sequence in longitudinal direction L of one first lower transverse thread I and a successive second lower transverse thread II. It is comprehensible, that a different ratio might be selected, e.g. a ratio of 1:2 or 2:1.
(31) According to various embodiments, the first lower transverse threads I may have thermosetting properties different from the second lower transverse threads II, e.g. a different shrinking behavior than the second lower transverse threads. This is made possible by the different binding of first and second lower transverse threads, which can be selected such, that it at least partially compensates the different thermosetting properties.
(32) According to various embodiments, the first lower transverse threads I may have a diameter different from the second lower transverse threads II, and/or the first lower transverse threads I may be made from a material different from the second lower transverse threads II, and/or the first lower transverse threads I and the second lower transverse threads II may be treated differently with influence on their thermosetting behavior, e.g. differently mechanically treated, e.g. differently stretched.
(33) According to various embodiments, the screen can be formed as a synthetic fabric, e.g. as a thermoset synthetic fabric. In the synthetic fabric at least the lower transverse threads 181-200, e.g. also the longitudinal threads 101-110 and transverse threads 121-180 extending in the upper fabric layer (see below as well as FIG. 2) and/or the lower longitudinal threads 111-120, are formed as synthetic threads.
(34) A respective of the lower transverse threads 181-200 can, e.g. be made of polyamide or polyester. For example, the first lower transverse threads I can be made of one of polyamide and polyester, wherein the second lower transverse threads II are made of the other one of polyamide and polyester. Alternatively, the first lower transverse threads I may, for example, be made of a first polyamide, wherein the second lower transverse threads II are made of another polyamide. Further alternatively, the first lower transverse threads I and the second lower transverse threads II can, for example, be made of the same synthetic material (e.g. polyamide 6.6), wherein the first lower transverse threads I and the second lower transverse threads II are stretched differently with influence on their thermosetting behavior. Further alternatively, the first lower transverse threads I and the second lower transverse threads II can, for example, be made of the same synthetic material (e.g. polyamide 6.6), wherein the first lower transverse threads I and the second lower transverse threads II have different diameters.
(35) As can be seen in the FIGS. 1b) and 1d) as well as FIGS. 2 and 3, the screen can, for example, be formed as a transverse thread-bound multi-layer fabric in which the binding threads are formed by transverse threads. See binding transverse threads 123, 126, 129, etc. It is to be understood, however, that also a different or additional form of layer binding might be selected, e.g. by using binding longitudinal threads.
(36) As shown in the FIGS. 2 and 3, the binding threads can, for example, be formed from transverse threads 123, 126, . . . extending in the upper fabric layer L1 and, on the one hand contributing to forming/completing the upper weave and, on the other hand, descending in sections into the lower fabric layer L2 to extend under at least one (here by way of example exactly one; see FIG. 3) lower longitudinal thread and thereby bind the lower fabric layer to the upper fabric layer.
(37) As shown in the FIGS. 3 and 4, the lower weave repeat can, for example, contain exactly 10 lower longitudinal threads 111-120. In the above described arrangement of the binding positions, this may, according to various embodiments, lead to a long transverse thread-float on the running side; see FIG. 4.
(38) As shown further in the FIGS. 3 and 4, in the lower weave repeat the ratio of lower transverse threads 181-200 to lower longitudinal threads 111-120 can, for example, be 2:1 or exactly 20:10, respectively. It is comprehensible that a different suitable ratio might be selected. The comparatively high number of lower transverse threads (which form the transverse thread-floats arranged on the running side) can, according to various embodiments, lead to an especially stable, durable running side and a sufficient and suitable number of lower transverse threads is provided, to which, for example, the different materials and/or different diameters can be distributed.
(39) As shown in FIG. 3, in the lower weave repeat, seen in a longitudinal direction L, always a transverse thread-binding to the upper fabric layer L1 can be provided, for example, between two transverse threads 181-200 arranged immediately next to each other, here by way of example, formed by exactly one binding transverse thread 123, 126, . . . extending temporarily in the lower fabric layer and thereby extending under at least one (here, by way of example, exactly one) longitudinal thread 111-120. For example, between the lower transverse threads 181 and 182 a transverse thread binding to the upper fabric layer L1 is provided, which is formed by the binding transverse thread 123 extending temporarily in the lower fabric layer L2 and thereby extending under the lower longitudinal thread 118. According to various embodiments, the upper and the lower fabric layer can thus be connected to each other consistently. It is comprehensible, that the transverse thread bindings may be distributed on the lower fabric layer in a different way.
(40) According to various embodiments, the diameter of the lower transverse threads 181-200 can, e.g. be larger than the diameter of the transverse threads 121-180 extending in the upper fabric layer and/or be larger than the diameter of the binding threads 123, 126, . . . , and/or the diameter of the lower transverse threads 181-200 can be larger than the diameter of the lower longitudinal threads 111-120, and/or the lower transverse threads 181-200 may have the largest diameter of all threads in the total weave. According to various embodiments, the lower transverse threads can thus be formed robustly and durably, whereas the paper side may be formed finely. According to various embodiments, the binding transverse threads may thus be shielded by lower transverse threads from the wear-causing components of the paper machine. According to various embodiments, an interference/interruption of the lower binding/weave structure by the binding transverse threads may thus at least be reduced.
(41) The upper fabric layer L1 is not limited to a certain configuration and, depending on the intended purpose, a suitable/appropriate paper side may be selected. With reference to FIG. 2, a possible configuration example is described below, which, however, is in no way to be understood as limiting. In other words, the running side according to FIGS. 3 and 4 (as well as the running side according to FIG. 5 or the running side according to FIG. 6) can also be combined with a different paper side or a different upper fabric layer and be attached/bound thereto.
(42) As shown in FIG. 2, the upper fabric layer L1 can, e.g. be formed from a plurality of uniformly structured upper weave repeats (e.g. consist thereof) each of which comprising (e.g. consisting of): upper longitudinal threads 101-110 extending exclusively in the upper fabric layer L1 (here, by way of example, in a number of 10 threads), upper transverse threads 121, 122, 124, 125, . . . , (here, by way of example, in a number of 40 threads), extending exclusively in the upper fabric layer and being interwoven with the upper longitudinal threads 101-110, thereby partially forming the upper weave, and binding transverse threads 123, 126, . . . , (here, by way of example in a number of 20 threads) that, on the one hand, complete the upper weave and, on the other hand, descend in sections into the lower fabric layer L2 to extend under at least one of the longitudinal threads extending in the lower fabric layer and thereby bind the lower fabric layer to the upper fabric layer.
(43) As shown in the FIGS. 2 and 3, the lower repeat and the upper repeat may be, for example, formed the same size, so that the total repeat comprises exactly one upper repeat and exactly one lower repeat. It is, however, also conceivable that the upper repeat is, e.g. smaller than the lower repeat. For example, the running side may be formed as a genuine plain weave (without using functional pairs), i.e. with an upper repeat of only 2 upper longitudinal threads and 2 upper transverse threads, wherein the running side is bound to the lower fabric layer by means of separate binding threads. In this case the total repeat would comprise one lower weave repeat and a plurality of upper weave repeats. It is also conceivable that the upper repeat is, e.g. larger than the lower repeat.
(44) As shown in FIGS. 2 and 3 (see also FIGS. 1a)-1d)), the fabric may, for example, have a total repeat, in which the ratio of upper longitudinal threads 101-110 to lower longitudinal threads 111-120 is 1:1, e.g. exactly 10:10.
(45) As shown in FIG. 2, the upper fabric layer L1 can, for example, be formed with a plain weave that, e.g. is formed from upper longitudinal threads 101-110 being interwoven with upper transverse threads 121, 124, . . . , as well as with imaginary uninterrupted upper transverse threads, provided by functional transverse thread pairs 122, 123; 125, 126; . . . , wherein, for example in longitudinal direction L one upper transverse thread and one functional transverse thread pair are arranged alternatingly behind each other.
(46) FIG. 5 shows the lower weave repeat of a paper machine screen, especially sheet forming screen (or forming screen respectively) formed as a multi-layer fabric according to a second embodiment (so-called 8-shaft configuration).
(47) The (not shown) paper side or upper fabric layer of the paper machine screen according to the second embodiment can, as described for the first embodiment, be selected appropriately and be, e.g. formed with a plain weave (e.g. with a plain weave formed following the example set by FIG. 2). A different appropriate upper fabric layer or upper weave can, however, be provided.
(48) The binding of the (not shown) upper fabric layer to the lower fabric layer can, analogously to the first embodiment, be realized by means of binding transverse threads. The binding or connecting, respectively, of the two fabric layers can, however, also be performed differently, e.g. by means of separate binding threads and/or binding longitudinal threads.
(49) Thus, only the lower fabric layer L2 and its lower weave repeat are described in detail below. Emphasize is being put on the differences to the first embodiment, in parts omitting repetition of identical or similar aspects with reference to the first embodiment.
(50) The lower fabric layer L2 of the screen according to the second embodiment is formed by (and, e.g. consists of) a plurality of uniformly structured lower weave repeats, each of which comprising longitudinal threads 501-508 extending in the lower fabric layer L2 and lower transverse threads 521-536 (e.g. the respective repeat consists of the mentioned threads), extending exclusively in the lower fabric layer L2 and being interwoven with the longitudinal threads 501-508 extending in the lower fabric layer.
(51) As shown in FIG. 5, the longitudinal threads extending in the lower fabric layer can be formed, e.g. as lower longitudinal threads 501-508 extending exclusively in the lower fabric layer L2 and being, for example, interwoven with the lower transverse threads 521-538 thereby completely forming the lower weave. In the following, reference is thus made to lower longitudinal threads even though the longitudinal threads 501-508 extending in the lower fabric layer may be configured differently.
(52) Analogously to the first embodiment, in the lower weave repeat the lower transverse threads 521-536 are respectively bound into the lower fabric layer each by exactly two lower longitudinal threads as a first longitudinal thread extends under the respective lower transverse thread at a first binding position x and a second longitudinal thread extends under the respective lower transverse thread at a second binding position x. As FIG. 5 shows a bottom view of the lower fabric layer, here both binding longitudinal threads of each lower transverse thread extend over the allocated transverse thread.
(53) Also analogously to the first embodiment, in the respective lower weave repeat the lower transverse threads 521-536 are bound into the lower fabric layer differently, thereby forming first lower transverse threads I and second lower transverse threads II, wherein at the first lower transverse threads I a shortest distance in transverse direction Q between the first and the second binding position x is larger than at the second lower transverse threads II.
(54) As shown in FIG. 5, the different binding results in the first lower transverse threads I forming a shorter float on the running side LS than the second lower transverse threads II. Cf., for example, the float of thread 530 to the float of thread 521.
(55) As can be seen in FIG. 5, the larger shortest distance in transverse direction Q at the first lower transverse threads I can, e.g. be achieved by the fact that at the first lower transverse threads between the first and the second binding position x at least one longitudinal thread extending over the lower transverse thread (in a plan view onto the top side of the lower fabric layer) more is arranged than at the second lower transverse threads II, for example exactly one longitudinal thread more or one additional thread, respectively.
(56) As can further be seen in FIG. 5, at the first lower transverse threads I the shortest distance in a transverse direction Qexpressed by lower longitudinal threads 501-508 positioned therebetween, extending over the lower transverse threadis, for example, exactly one longitudinal thread, wherein at the second lower transverse threads II the shortest distanceexpressed by lower longitudinal threads 501-508 positioned therebetween, extending over the lower transverse threadis zero longitudinal threads (respectively in a plan view onto the top side of the lower fabric layer).
(57) This means, in the lower weave repeat at the first lower transverse threads I respectively exactly one lower longitudinal thread 501-508 extending over the lower transverse thread can be arranged between the first and the second binding position x, wherein in the lower weave repeat at the second lower transverse threads II between the first and the second binding position x no longitudinal thread 501-508 extending over the lower transverse threads is arranged respectively, so that both binding positions are located immediately adjacent to each other (respectively in the plan view onto the top side of the lower fabric layer).
(58) As can further be seen in FIG. 5, the different shortest distance in transverse direction Q can, e.g. be achieved by the fact that the first lower transverse threads I are introduced/interwoven into the lower fabric layer with a course different from the second lower transverse threads II with respect to the lower longitudinal threads 501-508, wherein all of the first lower transverse threads I in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions x in transverse direction Q varies, and wherein all of the second lower transverse threads II in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions x in transverse direction Q varies.
(59) As can be seen in FIG. 5, the course of the first lower transverse threads I with respect to the lower longitudinal threads (in the plan view onto the top side of the lower fabric layer) can, e.g. be as follows: under five successive longitudinal threads, over one longitudinal thread, under one longitudinal thread and over one longitudinal thread. The course of the second lower transverse threads II with respect to the lower longitudinal threads (in the plan view onto the top side of the lower fabric layer) can, e.g. be as follows: under six successive longitudinal threads and over two successive longitudinal threads.
(60) As can be seen in FIG. 5, in the lower weave repeat the binding positions x of a respective first lower transverse thread I can be arranged, for example, offset in a transverse direction to the binding positions of the two first lower transverse threads adjacently arranged in longitudinal direction L, for example, offset to the binding positions of every other first lower transverse thread of the lower weave repeat. See, for example, the first lower transverse thread 523 and the two first lower transverse threads 521 and 525 arranged adjacently in longitudinal direction L. The same holds true for the second lower transverse threads II.
(61) As can further be seen in FIG. 5, in the lower weave repeat the binding positions x of two first lower transverse threads I, arranged directly next to each other in longitudinal direction L, can, for example, be arranged offset in a transverse direction always by the same amount of longitudinal threads 501-508 extending in the lower fabric layer and in the same direction. The same holds true for the second lower transverse threads. In FIG. 5, for both, the first lower transverse threads and the second lower transverse threads, a pitch of one lower longitudinal thread to the left has been selected (in the plan view onto the lower fabric layer thus a pitch of one lower longitudinal thread to the right).
(62) As can further be seen in FIG. 5, the ratio of first lower transverse threads I to second lower transverse threads II in the lower weave repeat, analogous to the first embodiment, can be, for example, 1:1, e.g. with a directly alternating arrangement in longitudinal direction L.
(63) Analogously to the first embodiment, according to various embodiments, the first lower transverse threads I may have thermosetting properties different from the second lower transverse threads II, e.g. have a different shrinking behavior compared to the second lower transverse threads.
(64) Analogously to the first embodiment, according to various embodiments, the first lower transverse threads I may have a diameter different from the second lower transverse threads II, and/or the first lower transverse threads I may be made of a material different from the second lower transverse threads II, and/or the first lower transverse threads I and the second lower transverse threads II may be treated differently with influence on their thermosetting behavior, e.g. mechanically treated differently, e.g. stretched differently.
(65) Analogously to the first embodiment, the screen can, according to various embodiments, be formed as a synthetic fabric, e.g. as a thermoset synthetic fabric. In the synthetic fabric, at least the lower transverse threads 521-536, e.g. also the lower longitudinal threads 501-508, are formed as synthetic threads.
(66) As shown in FIG. 5, the lower weave repeat may, for example, contain exactly 8 lower longitudinal threads 501-508; a so-called 8-shaft configuration, because the respective course of lower transverse threads is repeated after 8 lower longitudinal threads.
(67) As shown further in FIG. 5, in the lower weave repeat the ratio of lower transverse threads 521-536 to lower longitudinal threads 501-508 may, for example be 2:1 or be exactly 16:8, respectively.
(68) Analogously to the first embodiment, according to various embodiments, the diameter of the lower transverse threads 521-536 can, for example, be larger than the diameter of the transverse threads extending in the upper fabric layer (not shown) and/or be larger than the diameter of the binding threads (also not shown), and/or the diameter of the lower transverse threads 521-536 can be larger than the diameter of the lower longitudinal threads 501-508, and/or the lower transverse threads 501-508 can, in the total repeat, have the largest diameter of all threads.
(69) FIG. 6 shows the lower weave repeat of a paper machine screen formed as a multi-layer fabric according to a third embodiment (so-called 12-shaft configuration).
(70) Regarding the upper fabric layer and its binding to the lower fabric layer, the information given in the description of the second embodiment shall apply. Thus, only the lower fabric layer L2 and its lower weave repeat are described in detail below. Emphasize is being put on the differences to the first and second embodiment, in parts omitting repetition of identical or similar aspects with reference to the first/second embodiment.
(71) The lower fabric layer L2 of the screen according to the third embodiment is formed by (and, e.g. consists of) a plurality of uniformly structured lower weave repeats, each of which comprising longitudinal threads 601-612 extending in the lower fabric layer L2 and lower transverse threads 621-644 (e.g. the respective repeat consists of the mentioned threads), extending exclusively in the lower fabric layer L2 and being interwoven with the longitudinal threads 601-612 extending in the lower fabric layer.
(72) As shown in FIG. 6, the longitudinal threads extending in the lower fabric layer can be formed, e.g. as lower longitudinal threads 601-612 extending exclusively in the lower fabric layer L2 and being, for example, interwoven with the lower transverse threads 621-644 thereby completely forming the lower weave. In the following, reference is thus made to lower longitudinal threads even though the longitudinal threads 621-644 extending in the lower fabric layer may be configured differently.
(73) The lower transverse threads 621-644 are, analogously to the first and second embodiment, each bound twice into the lower fabric layer in the lower weave repeat, i.e. by exactly two lower longitudinal threads.
(74) Also analogously to the first and second embodiment, in the respective lower weave repeat the lower transverse threads 621-644 are bound into the lower fabric layer differently, thereby forming first lower transverse threads I and second lower transverse threads II, wherein at the first lower transverse threads I a shortest distance in transverse direction Q between the first and the second binding position x is larger than at the second lower transverse threads II.
(75) As shown in FIG. 6, the different binding has the result that the first lower transverse threads I form a shorter float on the running side LS than the second lower transverse threads II. Cf., e.g. the float of thread 638 with the float of thread 621.
(76) As can be seen in FIG. 6, in the lower weave repeat at the first lower transverse threads I between the first and the second binding position x, e.g. exactly one lower longitudinal thread 601-612, extending over the lower transverse thread, can be arranged respectively, wherein in the lower weave repeat at the second lower transverse threads II between the first and the second binding position x no lower longitudinal thread 601-612, extending over the lower transverse thread, is arranged respectively so that both binding positions are located immediately adjacent to each other (respectively in the plan view onto the top side of the lower fabric layer).
(77) As can further be seen in FIG. 6, the different shortest distance in transverse direction Q can, e.g. be achieved by the fact that the first lower transverse threads I are introduced/interwoven into the lower fabric layer with a course different from the second transverse threads II with respect to the lower longitudinal threads 601-612, wherein all of the first lower transverse threads I in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions x in transverse direction Q varies, and wherein all of the second lower transverse threads II in the lower weave repeat have, in principle, the same course and only the arrangement of the binding positions x in transverse direction Q varies.
(78) As can be seen in FIG. 6, the course of the first lower transverse threads I with respect to the lower longitudinal threads (in the plan view onto the top side of the lower fabric layer) can, for example be as follows: under nine successive lower longitudinal threads, over one longitudinal thread, under one longitudinal thread, and over one longitudinal thread. For example the course of the second lower transverse threads II with respect to the lower longitudinal threads (in the plan view onto the top side of the lower fabric layer) can be as follows: under ten successive longitudinal threads and over two successive longitudinal threads.
(79) As can be seen in FIG. 6, in the lower weave repeat, the binding positions x of a respective first lower transverse thread I can, for example, be offset in a transverse direction to the binding positions of the two first lower transverse threads adjacently arranged in longitudinal direction L, e.g. offset to the binding positions of every other first lower transverse thread of the lower weave repeat. See, e.g. the first lower transverse thread 623 and the two first lower transverse threads 621 and 625 arranged adjacently in longitudinal direction L. The same holds true for the second lower transverse threads II.
(80) As can further be seen in FIG. 6, in the lower weave repeat the binding positions x of two first lower transverse threads I, arranged directly next to each other in longitudinal direction L, can be arranged offset in a transverse direction always by the same amount of longitudinal threads 601-612 extending in the lower fabric layer and in the same direction. The same holds true for the second lower transverse threads. In FIG. 6, a pitch of five lower longitudinal threads to the left was selected by way of example for both the first lower transverse threads and the second lower transverse threads (in the plan view onto the lower fabric layer thus a pitch of five lower longitudinal threads to the right).
(81) As can further be seen in FIG. 6, the ratio of first lower transverse threads I to second lower transverse threads II in the lower weave repeat can, analogously to the first and second embodiment, e.g. be 1:1, for example with a direct alternating arrangement in longitudinal direction L.
(82) Analogously to the first and second embodiment, the first lower transverse threads I may, according to various embodiments, have thermosetting properties different from the second lower transverse threads II, e.g. a different shrinking behavior than the second lower transverse threads.
(83) Analogously to the first and second embodiment, the first lower transverse threads I may, according to various embodiments, have a diameter different from the second lower transverse threads II, and/or the first lower transverse threads I may be made of a material different from the second lower transverse threads II, and/or the first lower transverse threads I and the second lower transverse threads II may, with influence on their thermosetting behavior, be treated differently, e.g. differently mechanically treated, e.g. differently stretched.
(84) Analogously to the first and second embodiment, the screen may, according to various embodiments, be formed as a synthetic fabric, e.g. as thermoset synthetic fabric. In the synthetic fabric at least the lower transverse threads 621-644, e.g. also the lower longitudinal threads 601-612 are formed as synthetic threads.
(85) As shown in FIG. 6, the lower weave repeat may, for example, comprise exactly 12 lower longitudinal threads 601-612; so-called 12-shaft configuration, in which the respective course of transverse threads is repeated after 12 lower longitudinal threads, i.e. the respective transverse thread repeats, in the not-shown lower repeat arranged in transverse direction to the right of the lower repeat shown, its course shown in FIG. 6.
(86) As shown further in FIG. 6, in the lower weave repeat the ratio of lower transverse threads 621-644 to lower longitudinal threads 601-612 may, for example, be 2:1 or exactly 24:12, respectively.
(87) Analogously to the first and second embodiment, according to various embodiments, the diameter of the lower transverse threads 621-644 can, for example, be larger than the diameter of the transverse threads extending in the upper fabric layer (not shown) and/or be larger than the diameter of the binding threads (also not shown), and/or the diameter of the lower transverse threads 621-644 can be larger than the diameter of the lower longitudinal threads 601-612, and/or the lower transverse threads 621-644 can have the largest diameter of all threads in the total weave.
