EP0124083A1 - Woven web, especially for the paper industry - Google Patents

Abstract

1. A woven band with n weft planes, particularly conceived for paper manufacturing, comprising weft filaments (16) and warp filaments (1, 2, 3, 4, 5, 6, 7, 8), some of them serving to constitute loops (13) at the ends (12) of the band (11) and the zones (C) adjacent to the loops (13) having a thickness of m (m > 1) weft planes, characterized in that each zone (C) adjacent to the loops (13) comprises for each armure repeat of the warp filaments (1, 2, 3, 4, 5, 6, 7, 8) a first group (G1) of warp filaments (1, 2, 3, 4) forming a lower layer (20) of p weft planes and an upper layer (20') folded back on the lower layer (20) with (m-p) weft planes, and a second group (G2) of warp filaments (5, 7) forming a layer with m weft planes, some at least of the warp filaments (1, 2, 3, 4) of the first group (G1) serving to constitute loops (13).

Description

The present invention relates to a woven strip in weft planes intended in particular for the paper industry comprising weft threads and warp threads, some of which serve to constitute loops at the ends of the strip and whose areas adjacent to the loops. have a thickness of m (m 7 1) weft planes.

To join the loops, you can use a rod that you thread in the interlaced loops or use spirals which are threaded in the loops and connected themselves by a rod.

Such woven bands are used in particular in the paper industry in particular as a drying fabric.

The strip is wrapped around the drying cylinders of the papermaking machine and then joined.

It is known to form the area C adjacent to the loops to reweave this area by making the warp threads having reached the end take the place of the threads of the following warps which have been interrupted before area C. Some of these warp threads form loops at the end of the strip.

But these loops which are not in planes perpendicular to the wefts have a bulk in the direction of the wefts greater than the thickness of a wire. Since these loops must be interleaved with the loops on the other end, there can only be a density of 25% of loops at each end.

The woven strip according to the invention making it possible to obtain a higher density of loops is characterized in that each zone adjacent to the loops comprises, for each weave ratio of the warp threads, a first group of warp threads forming a lower layer of p weft planes and an upper layer folded over the lower layer having (m - p) weft planes and a second group of warp threads forming a layer having m weft planes, at least some of the warp threads of the first group serving to build loops.

In the woven strip according to the invention the loops obtained by the warp threads of group G1 are in planes perpendicular to the wefts and are therefore much less bulky. We can therefore increase the density of these loops and consequently increase the solidity of the junction.

According to one embodiment of the invention, the area near the loops is thicker than the rest of the strip (m> n), which makes it possible to use loops of a height greater than the thickness of the strip but obviously without exceed the thickness of the area around the loops to avoid marking the paper by the loops and abrasion of the loops.

According to one embodiment of the invention, the area near the loops has the same thickness as the rest of the strip, which prevents the paper from being marked by the extra thicknesses.

The invention will now be described in more detail with reference to particular embodiments cited by way of non-limiting example and shown in the accompanying drawings.

• FIG. 1 represents a woven strip of the known type.
• FIG. 2 represents one end of a woven strip according to the invention with extra thickness.
• FIG. 3 represents an end of a woven strip according to the invention without excess thickness.

The woven strip 11 shown in FIG. 1 has two ends 12 provided with loops 13. When the loops 13 are intertwined, a rod 14 can be introduced to attach the strip.

Each loop 13 is formed by a warp thread 15 which, during the reweaving with the weft threads 16, has taken the place of the neighbor warp thread 17 interrupted at a certain distance from the end 12.

In Figure 2 there is shown the end of the strip according to the invention.

The strip has two weft planes (a, b). The weft threads 16 are shown by dots. The end of the strip was cut into four zones in order A, B, C, D, zone D comprising the loops 13 and zone A the unmodified band.

Each armor ratio of the warp threads in zones B and C comprises a first group G1 made up of four warp threads 1, 2, 3, 4 and a second group G2 made up of four warp threads 5, 6, 7, 8.

The total thickness of area C is three weft planes a, b, c (m = 3).

The evolution of the sons of the first group G1 is shown in the first plan and that of the second group G2 in the background.

The warp threads 1, 2, 3, 4 work on two planes (p = 2) of weft a, b in the areas A and B and also in the area C where they form the lower layer 20. The warp threads 1 , 2, 3, 4 pass under a weft thread of plane a then on a weft thread of plane b located two further apart intervals and then under a weft thread of plane a located two intervals further away and so on. Zone A represents the band. In zone D the wires 1 to 4 form four adjacent loops 13.

The wires 1, 2, 3, 4 form an upper layer 20 'folded over the lower layer 20 making extra thickness on the reverse of the strip. The upper layer 20 'is located only in zone C and the wires 1, 2, 3, 4 work in a single plane c (m - p = 1). Each warp thread 1, 2, 3, 4 passes successively over a weft thread and below three weft threads. Wires 1 to 4 are interrupted towards the end of zone C.

The warp threads 5, 6, 7, 8 work between the two planes a, b in zone A. In zone B the wires 6 and 8 are interrupted. The wires 5 and 7 work between two planes a, b in zone B and between three planes a, b, c in zone C.

Arrived at the end of zone C the threads 5 and 7 were arranged during the reweaving by passing them in place of the threads 6 and 8 going up to the vicinity of the end of the threads 6 and 8 where they are interrupted. Thus in zone C each wire 5 and 7 passes under a weft wire of plane a, then on a weft wire of plane c located two intervals further and so on until the end of zone C. Then while returning each wire 5 and 7 passes on the weft son of plane c and under the weft son of plane a along a path symmetrical with respect to plane b of the path followed on the outward journey.

To make zones B, C, D you can use a splicing machine (machine to reweave the fabric perpendicular to its original weaving direction).

In zone C the wires 5 and 7 serve to connect the lower layer 20 to the upper layer 20 '.

For group G2, the four wires 5, 6, 7, 8 could alternatively be used up to the end of zone C adjacent to zone D in changing the four wires between the three planes a, b and c and cutting these four wires at the end of the area. C.

Obviously if in zone C there were four weft planes we could add between zone B and zone C a zone C 'with three weft planes similar to zone C of the current figure 2 so that the variation of the extra thickness don't be too abrupt.

In Figure 3 there is shown a woven strip in which there is no allowance in the area C near the loops (m = n).

The strip (zone A) has two weft planes a, b (n = 2).

In zone C the wires of group G1, 1, 2, 3, 4 form a lower layer 20 to a plane (p = 1) and an upper layer 20 'to a plane (m - p = 1) with four loops 13 in zone D.

The wires from group G2, 6 and 8 are interrupted in zone B and the wires 5 and 7 constitute zone C. These wires 5 and 7 are rewoven, taking the place of wires 6 and 8 as in the example in the figure 2.

In FIGS. 2 and 3, only one end of the strip has been shown, but it is clear that the other end is preferably formed in a similar manner so that the zones comprising the loops can cooperate as closely as possible in joining the the band.

Claims (3)

1 / Woven strip in weft planes intended in particular for the paper industry
comprising weft threads (16) and warp threads (1, 2, 3, 4,5, 6, 7, 8), some of which serve to form loops (13 at the ends (12) of the strip (11) ) and whose adjacent zones (C) of the loops (13) have a thickness of m (m> 1) weft planes characterized in that each zone (C) adjacent to the loops (13) comprises for each armor ratio warp threads (1, 2, 3, 4, 5, 6, 7, 8) a first group (G1) of warp threads (1, 2, 3, 4) forming a lower layer (20) of p planes weft and an upper layer (20 ') folded over the lower layer (20) having (m - p) weft planes and a second group (G2) of warp threads (5, 7) forming a layer having m weft planes , at least some of the warp threads (1, 2, 3, 4) of the first group (G1) serving to constitute loops (13). 2 / Woven strip according to claim 1, characterized in that the zone (C) adjacent to the loops (13) is thicker than the rest of the strip (11) (m> n). 3 / woven strip according to claim 1, characterized in that the zone (C) adjacent to the loops (13) at the same thickness as the rest of the strip (11) (m = n).

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