Fabric belt

Abstract

The invention relates to a fabric belt for the production of a corrugated cardboard web in a corrugated cardboard machine having several warp layers. In at least one edge region of the fabric belt, a surface of its upper warp layer has at least first regions (21) which consist of first yarns, and second regions (22) which consist of second yarns. The first yarns contain 30% b.w. to 100% b.w. aromatic polyamides, 0% b.w. to 70% b.w. aliphatic and/or alicyclic polyamides and 0% b.w. to 5% b.w. other materials. The total of the polyamides and other materials thus gives 100% b.w. The second yarns contain 50% b.w. to 85% b.w. polyester and/or aliphatic polyamides and/or alicyclic polyamides, 15% b.w. to 50% b.w. cellulose and 0% b.w. to 5% b.w. other materials. The total of the polyesters, polyamides, cellulose and other materials gives 100% b.w.

Claims

1. A fabric belt (1) for the production of a corrugated cardboard web in a corrugated cardboard machine having several warp layers (71, 72, 73), characterised in that, in at least one edge region (12, 13) of the fabric belt (1), a surface of its upper warp layer (71) has at least first regions (21) which consist of first yarns (51), and second regions (22) which consist of second yarns (52), wherein the first yarns (51) contain 30% b.w. to 100% b.w. aromatic polyamides, 0% b.w. to 70% b.w. aliphatic and/or alicyclic polyamides and 0% b.w. to 5% b.w. other materials, wherein the total of the polyamides and other materials gives 1.00% b.w., and the second yarns (52) contain 50% b.w. to 85% b.w. polyester and/or aliphatic polyamides and/or alicyclic polyamides, 15% b.w. to 50% b.w. cellulose and 0% b.w. to 5% b.w. other materials, wherein the total of the polyesters, polyamides, cellulose and other materials gives 100% b.w.

2. The fabric belt (1) according to claim 1, characterised in that the first regions (21) cover to of the surface of the at least one edge region (12, 13) and the second or more regions (22) cover the rest of the surface.

3. The fabric belt (1) according to claim 1, characterised in that the width (R) of each edge region (12, 13) ranges from 400 mm to 650 mm.

4. The fabric belt (1) according to claim 1, characterised in that it has two edge regions (12, 13), between which a central region (11) is located which only has second yarns (52) on the surface of its upper warp layer.

5. The fabric belt (1) according to claim 4, characterised in that the central region (11) has a width (Z) in the range from 800 mm to 2,100 m.

6. The fabric belt (1) according to claim 1, characterised in that the first yarns (51) and the second yarns (52) are staple fibre yarns.

7. The fabric belt (1) according to claim 1, characterised in that the first yarns (51) and the second yarns (52) respectively have a yarn count in the range from 1,000 dtex to 5,000 dtex.

8. The fabric belt (1) according to claim 1, characterised in that the first yarns (51) contain at least 30% b.w. meta-aramid.

9. The fabric belt (1) according to claim 1, characterised in that the first yarns (51) contain at least 10% b.w. para-aramid.

10. The fabric belt (1) according to claim 1, characterised in that the aliphatic and/or alicyclic polyamides of the first yarns (51) are selected from PA6 and/or PA66.

11. The fabric belt (1) according to claim 1, characterised in that the warp threads (411, 412, 413, 414) of the upper warp layer (71) consist of the first yarns (51) and the second yarns (52).

12. The fabric belt (1) according to claim 1, characterised in that it has an upper warp layer (71), an inner warp layer (72), a lower warp layer (73), binding threads (401, 402, 403, 404) as well as two to four layers of weft threads (6).

13. The fabric belt (1) according to claim 1, characterised in that it has binding threads (401, 402, 403, 404) which consist of the second yarns (52).

14. The fabric belt (1) according to claim 1, characterised in that an inner warp layer (72) has warp threads (409, 410) made from third yarns (53) which consist of polyester.

15. The fabric belt (1) according to claim 14, characterised in that the third yarns (53) are multifilament yarns.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) An exemplary embodiment of the invention is shown in the drawings and will be explained in more detail in the following description.

(2) FIG. 1 shows a top view of a fabric belt according to one exemplary embodiment of the invention.

(3) FIG. 2 shows a top view of the surface of an edge region of a fabric belt according to one exemplary embodiment of the invention.

(4) FIG. 3 shows the weave design of the edge region of the upper warp layer of a three-layered fabric belt according to one exemplary embodiment of the invention.

(5) FIG. 4a schematically shows a stitch during the production of the edge region of a fabric belt according to one exemplary embodiment of the invention.

(6) FIG. 4b shows another stitch during the production of the edge region of a fabric belt according to one exemplary embodiment of the invention.

(7) FIG. 4c shows yet another stitch during the production of a fabric belt according to one exemplary embodiment of the invention.

(8) FIG. 5 shows a schematic longitudinal section of the edge region of a fabric belt according to one exemplary embodiment of the invention.

EXEMPLARY EMBODIMENT OF THE INVENTION

(9) A section of a fabric belt 1, which can be used as an upper belt in a corrugated cardboard machine, is shown in FIG. 1. This has a central region 11 and two edge regions 12, 13. The edge regions 12, 13 run parallel to the longitudinal direction 14 of the fabric belt 1. In the present exemplary embodiment, the central region 11 has a width Z of 800 mm and the edge regions 12, 13 each have a width R of 400 mm.

(10) The fabric belt 1 is drawn into the corrugated cardboard machine in the middle as a top belt and extends by a maximum of +/0.5 cm in width. The corrugated cardboard runs underneath the belt, wherein the corrugated cardboard edges should lie within the edge regions 12, 13. The upper warp layer of the fabric belt 1 thereby points downwards and touches the corrugated cardboard.

(11) The surface of the edge regions 12, 13 is shown in FIG. 2. This has first regions 21 made from first yarns and second regions 22 made from second yarns. The second regions 22 are connected to one another in the form of a grid pattern such that they separate the first regions 21 from one another. As a result, the first regions 21 form rhombic islands which do not touch one another. In the present case, the first yarns are Nm 20/6 staple fibre yarns with an effective yarn count of 3,000 dtex, which contain 50% b.w. meta-aramid, 35% b.w. polyamide 66 and 15% b.w. para-aramid. The second yarns are Nm 20/6 staple fibre yarns with a yarn count (effective yarn count) of 3,000 dtex, which contain 65% b.w. polyester and 35% b.w. viscose. The entire surface of the central region 11 consists only of the second yarns.

(12) While the second yarns are raw white, the para-aramid portion of the first yarns gives them a yellow colour. The edge regions 12, 13 of the fabric belt 1 can therefore be visually distinguished from the fully white central region 11 by a yellow and white pattern.

(13) In the present exemplary embodiment, the fabric belt 1 is designed as a three-layered fabric. A section from the pattern repeat of its weave design is shown in FIG. 3. It has twelve rounds 301-312. The base warps are guided in 14 shafts 401-414, wherein only the upper base warp, which extends in the shafts 411-414 shown, is relevant for the formation of the first regions 21 and the second regions 22 on the surface of the edge regions 12, 13.

(14) The indentation, which is used to achieve the pattern of the edge regions 12, 13 with the first regions 21 and the second regions 22, is shown for shafts 401-414 in FIGS. 4a to 4c. The first yarns 51 are only used in shafts 411-414. The second yarns 52 are used in shafts 401-408 and 411-414. In shafts 409 and 410, third yarns 53 are used. These are polyester multifilament yarns with a yarn count of 3,300 dtex. In shafts 401-404 and 409-410, two threads of the yarns n identified in FIGS. 4a to 4c are respectively guided through the heddles which are strung in the shafts. In shafts 405-408 and 411-414, three threads of the identified yarns are respectively guided through the heddles. The first stitch takes place according to FIG. 4a on the rear heddle rod of the weaving machine used. The second stitch takes place according to FIG. 4b on the front heddle rod. The third stitch takes place according to FIG. 4c on the rear heddle rod. The fourth stitch takes place according to FIG. 4a on the front heddle rod. The fifth stitch takes place according to FIG. 4b on the rear heddle rod. The sixth stitch takes place according to FIG. 4c on the front heddle rod. These six stitches are repeated until the desired width of the edge regions 12, 13 is achieved. In this way, a fabric is obtained in the edge regions 12, 13, whose top warp layer consists of one third of the first yarns 51 and two thirds of the second yarns 52 on its surface.

(15) A longitudinal section of one of the edge regions 12, 13 is shown in FIG. 5. There, the warp threads and binding threads of the fabric are referred to using the same reference numerals which were used in FIGS. 4a to 4c for the respective shafts in which they are guided. In addition to the warp threads and binding threads, the weft threads 6 are also shown. It can be seen that the fabric has three warp layers 71, 72, 73. In the upper warp layer 71, which has the first regions 21 and the second regions 22 on its surface, four warp threads 411-414, which extend offset relative to one another, are provided, which extend both inwards towards the inner warp layer 72 and outwards towards the paper side, each over at least two weft threads 6. According to the depiction in FIGS. 4a to 4c, the warp threads 411-414 consist of one third of the first yarns 51 and two thirds of the second 52. The inner warp layer 72 has two warp threads 409, 410, which are offset relative to each other and which consist of third yarns 53 and each extend over two weft threads 6. The lower warp layer 73 consists of four warp threads 405-408 which extend offset relative to one another and which extend inwards, i.e. towards the inner warp layer 72, over only one weft thread 6 and outwards, over at least three weft threads 6. The warp threads 405-408 of the lower warp layer 73 consist of second yarns 52. The three warp layers 71, 72, 73 are interwoven with one another by means of binding threads 401-404. The binding threads are respectively divided into two thread groups, wherein the binding threads 403, 404 forming a thread group extend offset with respect to one another and bind the upper warp layer 71 to the inner warp layer 72. These binding threads 403, 404 are alternately guided around a weft thread 6 in the upper warp layer 71 and a weft thread 6 in the inner warp layer 72. In a corresponding manner, the thread group formed from the binding threads 401, 402 binds the lower warp layer 73 to the inner warp layer 72. All weft threads 6 consist of polyester staple fibre yarns. A thread is understood above to mean in each case a bundle of several threads, which respectively consists of two threads for the binding threads 401-404 and for the warp threads 409-410 of the inner warp layer 72 and respectively consists of three threads for the warp threads 405-408 of the lower warp layer 73 and warp threads 411-414 of the upper warp layer 71. Only the weft threads 6 respectively consist of only one thread.

(16) During the operation of a corrugated cardboard machine, sections of the edge regions 12, 13 which are not covered by the corrugated cardboard web are temporarily exposed to the heating plates of the corrugated cardboard machine. Thermal and mechanical damage to the edge regions 12, 13 is thereby prevented by the first regions 21 which consist of the first yarns 51. The sections of the edge regions 12, 13 which cover the corrugated cardboard absorb water and steam from the corrugated cardboard web as part of moisture management. Here, water can be absorbed between the staple fibres by the first yarns 51 and by the second yarns 52. In addition, the viscose portion of the second yarns 52 can absorb up to 80% of its own weight of moisture. The edge regions 12, 13 of the fabric belt 1 thus fulfil a hybrid function of thermal and mechanical protection and moisture management.