JPH0215673B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an endless two-layer molded fabric for paper making, particularly for use in the wire part of a paper machine, which has excellent surface smoothness, abrasion resistance and dimensional stability. The present invention relates to an endless two-layer molded fabric for paper making.

Conventional techniques and their problems In recent years, there has been a demand for forming fabrics for paper manufacturing that have increasingly finer texture and excellent surface smoothness. The double-woven fabric, which is now being used in some areas, has a weaving structure with a single warp and double weft, and the warp (thread in the direction of the paper machine) is the weft (thread in the cross direction of the paper machine) of the upper layer. It is woven under the weft threads of the upper and lower layers, and the weft threads of the upper and lower layers are joined together. Therefore, while the machine direction yarns are exposed on the papermaking side of the fabric, they are also exposed on the wear side of the fabric that comes into contact with the dewatering equipment (eg, suction box, hydro-oil) of the paper machine. In order to provide smoothness to the fabric surface on the paper making side, the top of the upper knuckle formed by combining the machine direction yarns with the machine weft direction yarns must be On the wear side of the fabric, the apex of the lower knuckle of the machine direction yarn should be in approximately the same plane as the apex, and to protect the machine direction yarns from abrasion, The structure must be such that it is located above, that is, inside, the plane formed by. Furthermore, in order to minimize the elongation of the fabric during use, the machine direction yarns must be shaped with as little bending as possible. It is extremely difficult to satisfy all three of these requirements with a single machine direction yarn. In addition, very recently, in order to compensate for the above-mentioned defects of single warp and double weft weaving, papermaking fabrics with double warp and double weft weaving have been experimentally used. In order to bind the upper net and the lower net together, they are connected using binding yarns inserted separately from the warp and weft yarns that constitute these fabrics. For this reason, the structure of the woven fabric itself becomes complicated, and the so-called splicing process to make it endless becomes extremely complicated, as in the case of the single warp and double weft weaving mentioned above. The occurrence of problems has become unavoidable. However, in the case of the above-mentioned warp double weft double weave, separate binding yarns are used, which causes the surface of the fabric to collapse, and in order to reduce this phenomenon, warp yarns are used as binding yarns. It is necessary to use a thread thinner than the weft, which has the drawback of being worn out and broken during use, and therefore, it has not yet been used on a continuous basis. In addition, both the warp single weft double weave and the warp double weft double weave mentioned above are extremely difficult to weave endlessly (so-called bag weave) due to their structure, so they have no choice but to be made endless by so-called weaving. This complicates the process, and troubles at the weaving joint are unavoidable.

Means for Solving the Problems The present invention provides a novel endless two-layer molded fabric for papermaking that solves the drawbacks of the above-mentioned double-woven fabrics.

The present invention relates to an endless two-layer formed fabric for paper manufacturing, which is composed of an upper layer fabric and a lower layer fabric: The upper layer fabric has a 1/1 plain weave structure with machine direction yarns and machine direction yarns; The lower layer fabric has an upper layer fabric. Machine direction yarns arranged vertically in pairs with the machine direction yarns of the upper layer fabric at the same number density per unit width of the machine direction yarns of the fabric, and per unit length of the machine direction yarns of the upper layer fabric. machine direction yarns arranged at a number density lower than the number density; every other machine direction yarn of the lower layer fabric is
Woven into machine weft yarn and plain weave structure of lower layer fabric,
Every other remaining machine direction yarn of the lower layer fabric is not interwoven with either the machine direction yarns of the upper layer fabric or the machine direction yarns of the lower layer fabric, and the machine direction yarns of the upper layer fabric and the machine direction yarns of the lower layer fabric are interwoven. between the machine direction yarns and extending substantially linearly in the machine direction; one of the two or three of the four machine direction yarns of the upper layer fabric; , is woven into a 1/1 plain weave structure with only the machine direction yarns of the upper layer fabric, and the remaining one thread among the machine direction yarns of the upper layer fabric is woven with the machine direction yarns of the upper layer fabric and the plain weave structure. In addition, the machine direction yarns of the upper layer fabric are located above the machine direction yarns of the upper layer fabric and are arranged in pairs above and below the machine direction yarns of the upper layer fabric. passing under the machine direction threads of the bottom fabric and under the machine direction threads of the top fabric where the direction threads are located above the machine direction threads of the bottom fabric;
Thereby, every other machine direction yarn of the upper layer fabric integrally connects the upper layer fabric and the lower layer fabric; it is an endless two-layer formed fabric for paper making.

Function In the endless two-layer molded fabric for paper making of the present invention constructed as described above, since the upper layer fabric is a 1/1 plain weave, when an appropriate tension is applied to the entire fabric in the machine direction (longitudinal direction), , the upper knuckle of the machine direction yarn pushes down the machine weft direction yarn, and the lower knuckle of the machine direction yarn pushes up the machine weft yarn, thereby causing the apex of the upper knuckle of the machine direction yarn and the apex of the upper knuckle of the machine weft direction yarn to Since these can be made to touch substantially the same plane, the surface of the paper formed on the upper surface of this fabric can be made smooth. In a single-layer plain weave, such a configuration would stretch in the machine direction, making it impractical; however, in the fabric of the present invention, the machine direction yarns in the upper layer are stretched in the machine direction, rather than being subjected to tension in the endless direction. This elongation occurs because the machine direction yarns, which are not interwoven with the machine direction yarns and extend substantially straight in the machine direction, bear this tension. The problem does not occur.

In addition, in the formed fabric of the present invention, one of the two machine direction yarns or three of the four machine direction yarns of the upper layer fabric are only the machine direction yarn of the upper layer fabric and a 1/1 plain weave. In addition to being woven into the plain weave structure with the machine direction yarns of the top layer fabric, one remaining thread of the machine direction yarns of the top layer fabric is woven into the plain weave structure with the machine direction yarns of the top layer fabric. A location where the machine direction yarns of the lower layer fabric, which are located above the machine direction yarns of the upper layer fabric and are arranged vertically in pairs with the machine direction yarns of the upper layer fabric, are located above the machine direction yarns of the lower layer fabric. passes under the machine direction yarns of the lower layer fabric and under the machine direction yarns of the upper layer fabric, whereby every other machine direction yarn of the upper layer fabric unites the upper layer fabric and the lower layer fabric. The structure is simple and it is not difficult to splice the weave, and it is especially easy to make a hollow weave.

The formed fabric of the present invention may be weaved into an endless band and then spliced in an endless form, but due to its structure, it is particularly suitable for weaving as an endless band in a hollow weave. When weaving in a bag weave, the machine direction yarns of the lower layer fabric are relatively straight, and the machine weft direction yarns (warp threads during weaving) are bent, resulting in what is called a weft abrasion type where the machine weft direction yarns bear the wear. Therefore, there is no disadvantage that the fabric stretches as wear progresses, and a long life can be achieved. In addition, since the number density of machine weft direction yarns per unit length of the lower layer fabric is smaller than the number density of machine direction yarns of the upper layer fabric, water-based properties are good.
The number is preferably 1/2 to 1/3. Therefore, in order to extend the wear life, abrasion resistance can be improved by increasing the diameter of the machine direction threads in the lower layer fabric, but since the number of machine direction threads in the lower layer fabric is reduced, it is possible to Does not adversely affect paper-making properties.

Examples Examples of the endless two-layer molded fabric for paper manufacturing of the present invention will be described below with reference to the drawings.

FIG. 1 is a top plan or surface view of a first embodiment of the present invention, showing only the upper layer fabric 30 and omitting the lower layer fabric. FIG. 2 is a bottom plan or back view of the first embodiment, showing only the lower layer fabric 40 and omitting the upper layer fabric.

The upper layer fabric 30 includes machine direction yarns 1, 3, i.e., yarns 1, 3 that extend in the running direction of the fabric when placed on the paper machine, and machine direction yarns 10, i.e., machine direction yarns 1, 3.
3 and threads 10 extending in the width direction of the paper machine to form a 1/1 plain weave structure.

The lower layer fabric 40 has the same number density per unit width of the machine direction yarns 1 and 3 of the upper layer fabric 30,
The machine direction yarns 1 and 3 of the upper layer fabric, the machine direction yarns 2 and 4 arranged in pairs above and below, respectively, and the upper layer fabric 3
0 machine direction yarns 2 arranged at a number density of 1/2 of the number density per unit length of the machine direction yarns 10
It is composed of 0 and 21.

FIG. 3 is a longitudinal sectional view of the upper layer fabric 30 of FIG. 1 and the lower layer fabric 40 of FIG. 2, taken along line 3-3, respectively, as viewed in the direction of the arrow.

Similarly, Fig. 4 shows line 4-4, Fig. 5 shows line 5-5.
and FIG. 6 are longitudinal cross-sectional views taken along line 6-6, respectively, in the direction of the arrows.

This will be explained with reference to FIGS. 2 to 6. Every other yarn 2 among the machine direction yarns of the lower layer fabric 40 is woven with the machine direction yarns 20 of the lower layer fabric 40 into a plain weave structure. The remaining every other yarn 4 among the machine direction yarns of the lower layer fabric 40 is the machine direction yarn 10 of the upper layer fabric.
It is not interwoven with any of the machine direction yarns 20 of the lower layer fabric and is disposed between the machine direction yarns 10 and 20 of both layers, extending substantially linearly in the machine direction.

Of the machine direction yarns of the upper layer fabric 30, every other yarn 3 (FIGS. 1, 4, and 6) is woven into a 1/1 plain weave structure with only the machine direction yarns 10 of the upper layer fabric. ing. Remaining every other yarn 1 of the machine direction yarns of the upper layer fabric 30 (FIGS. 1, 3, and 5)
In addition to being woven into a plain weave structure with the machine direction yarns 10 of the upper layer fabric 30, the machine direction yarns 12 and 21 of both layers are woven into a plain weave structure with the machine direction yarns 12 and 21 of both layers at the location indicated by P-P in FIG.
, thereby passing under both of the upper fabric 30
and the lower layer fabric 40 are integrally connected by the thread 1. The location indicated by P-P in FIG. 3 is the upper layer fabric 3.
0 machine direction yarns 10 are located above the machine direction yarns 1 of the upper layer fabric 30 interwoven therewith, and the lower layer fabric 40 is arranged in pairs above and below the machine direction yarns 10 of the upper layer fabric 30. is defined as the location where the machine direction yarns 20 of are located above the machine direction yarns 2 (FIG. 3) of the underlying fabric 40.

FIG. 7 is a sectional view taken along line 7--7 in FIGS. 1 and 2 in the direction of the arrow. Similarly, the 8th
9 and 10 show cross-sectional views taken in the direction of the arrows along lines 8-8, 9-9 and 10-10, respectively.

Next, a second embodiment of the present invention will be described in FIGS. 11 to 22.
As shown in the figure. The second embodiment differs from the first embodiment in that the number density of machine direction yarns 20 in the lower layer fabric is one-third of the number density of machine direction yarns 20 in the upper layer fabric. One in four machine direction yarns connects the upper and lower fabrics. The other points are the same as the first embodiment.

FIG. 11 is an upper plan or surface view showing a second embodiment of the invention, showing only the upper layer fabric and omitting the lower layer fabric.

FIG. 12 is a bottom plan view or back view of the second embodiment, showing only the lower layer fabric and omitting the upper layer fabric.

13, 14, 15, and 16 are lines 13-13 and 14-1 in FIGS. 11 and 12.
14, 15-15, and 16-16 as viewed in the direction of the arrows, respectively.

Figures 17, 18, 19, 20, 21, and 22 are the same as those in Figures 11 and 12.
17-17 line, 18-18 line, 19-19 line, 2
Cross-sectional views taken along lines 0-20, 21-21, and 22-22 in the direction of the arrows are shown, respectively.

In FIGS. 1 to 10 of the first embodiment and FIGS. 11 to 22 of the second embodiment, the same reference numerals indicate the same components.

In the fabric of the present invention, the number of machine weft yarns per unit length of the lower layer fabric is smaller than the number of machine weft yarns per unit length of the upper layer fabric, but the ratio is particularly 1/2 to 1/4. 1/2 to 1/3 is suitable. Since the machine direction yarns 20 of the lower layer fabric face the dewatering elements of the paper machine and bear the wear, the number density of the machine direction yarns of the lower layer fabric is set to one quarter of the number density of the machine direction yarns of the upper layer fabric. It is not desirable to make it smaller. Moreover, 1/1 is not preferable because the aqueous property becomes poor.

In the above explanation, machine direction yarn refers to yarn in the direction in which the endless fabric runs in the papermaking machine (same as the endless direction).
Further, the term "machine weft direction thread" means the thread in the width direction on the paper making machine.

In addition, although the machine direction yarns and machine direction yarns of the upper and lower layers are shown arranged vertically and orderly in the drawing, this is not necessarily the case; this is merely to clarify the weaving structure of the fabric. There is no problem even if the upper and lower threads are slightly misaligned. In the case of this bag weave, naturally, two pieces of the machine direction yarns of both the upper and lower layers are warped as the warp of the loom, and each of the machine direction yarns of the upper and lower layers are sequentially set in a spiral shape as the weft to form an endless fabric.

As the threads used in the fabric of the present invention, synthetic resin monofilaments such as polyester, polyamide, polyethylene, polypropylene, and polyvinylidene fluoride, twisted threads, or multifilament threads can be used alone or in combination. The combination of these thread materials is determined by the usage conditions of the papermaking fabric.

Typically, polyester monofilaments are used in which the machine direction yarns and machine direction yarns of the top and bottom fabrics coexist.

In addition, for usage conditions where the back side of the fabric is easily abraded due to the filler used in paper making, both the machine direction yarn and the machine direction yarn of the upper layer fabric are made of polyester monofilament, and the machine direction yarn of the lower layer fabric is made of polyester monofilament. A two-layer fabric consisting of a monofilament, a polyamide monofilament in every or every other yarn in the cross machine direction is suitable.

In addition to the above, for papermaking conditions that require abrasion resistance, in addition to the above, among the machine direction yarns of the upper layer fabric, the machine direction yarns of the lower layer fabric and the machine direction yarns woven in the plain weave structure are polyamide monofilament yarns. It is preferable to provide a two-layer fabric in which the machine direction yarns, which are not interwoven with the machine direction yarns that alternate therewith and which extend linearly, are polyester monofilament or multifilament yarns.

Furthermore, for use conditions where the front side of the fabric is susceptible to abrasion, such as fabrics for twin-type paper machines that use two fabrics, all or every other yarn in the machine cross direction of the upper fabric may be It is preferable to use polyamide monofilaments, and if the machine direction threads are made of polyamide monofilaments, the abrasion resistance of the front side can be further enhanced. In this way, the two-layer fabric of the present invention can exhibit its effects even more by selecting the yarn material or yarn diameter that suits the conditions of use.

In addition, the endless fabric obtained by piecing or bag weaving as described above is supplied to a paper making machine through a finishing process including a usual heat treatment process and, if necessary, a resin processing process.

Effects of the Invention Since the endless two-layer molded fabric of the present invention has the above-described structure and function, it has the following effects.

(1) On the paper side of the upper layer fabric, by appropriately selecting the machine direction tension during finishing of the fabric, the upper knuckle tops of the machine direction yarns of the upper layer fabric and the upper knuckle tops of the machine direction yarns are almost unified. It can be formed in a positional relationship that is in contact with a plane. However, in this case, it does not have the disadvantage of stretching in the machine direction unlike single-layer plain weave. This is because the machine direction yarns (especially every other yarn) of the underlying fabric carry the tension.

Wire marks on the paper are therefore reduced.

(2) Since the number density of machine direction yarns in the lower layer fabric is smaller than the number density of machine direction yarns in the upper layer fabric, the machine direction yarns of the lower layer fabric woven with this are intersected with the machine direction yarns. There is little bending at points, and every other machine direction yarn is inserted in a linearly extending state that does not interweave with the machine direction yarns, so it can withstand tension applied in the machine direction and the fabric itself will not be woven during use. The fabric does not elongate and has excellent dimensional stability.

(3) Since the number density of the machine direction yarns of the lower layer fabric is smaller than the number density of the machine direction yarns of the upper layer fabric, it is possible to use a yarn with a larger diameter without impairing the water resistance, and therefore it is even more abrasion resistant. can be made into a sex.

[Brief explanation of drawings]

FIG. 1 is an upper plan view showing a first embodiment of the present invention, in which only the upper layer fabric is shown and the lower layer fabric is omitted. FIG. 2 is a bottom plan view of the first embodiment, showing only the lower layer fabric and omitting the upper layer fabric. 3, 4, 5, and 6 correspond to lines 3-3, 4-4, 5-5, and 6- of FIGS. 1 and 2.
A vertical cross-sectional view taken along each of the six lines and viewed in the direction of the arrow is shown. Figures 7, 8, 9, and 10 are lines 7-7, 8-8, and 9- of Figures 1 and 2.
Cross-sectional views taken along lines 9 and 10-10 in the direction of the arrows are shown, respectively. FIG. 11 is a top plan view of a second embodiment of the present invention, showing only the upper layer fabric and omitting the lower layer fabric. Figure 12 shows the second
In the lower plan view of the embodiment, only the lower layer fabric is shown and the upper layer fabric is omitted. Figures 13, 14, 15 and 16 are the same as those in Figures 11 and 12.
3-13 line, 14-14 line, 15-15 line and 1
FIG. 6 is a longitudinal cross-sectional view taken along the line 6-16 and viewed in the direction of the arrows. Figure 17, Figure 18, Figure 19, Figure 2
Figure 0, Figure 21 and Figure 22 are the same as Figure 11 and Figure 1.
Lines 17-17, 18-18, and 19-19 in Figure 2
line, 20-20 line, 21-21 line and 22-22
Each shows a cross-sectional view along the respective line in the direction of the arrow. 30... Upper layer fabric, 40... Lower layer fabric, 1, 3... Machine direction yarn of upper layer fabric, 2, 4... Machine direction yarn of lower layer fabric, 10... Machine cross direction yarn of upper layer fabric, 20... Machine cross direction of lower layer fabric thread.

Claims (1)

[Scope of Claims] 1. In an endless two-layer formed fabric for paper manufacturing comprising an upper layer fabric and a lower layer fabric: The upper layer fabric has a 1/1 plain weave structure with machine direction yarns and machine weft direction yarns; The lower layer fabric is the number of machine direction yarns per unit width of the machine direction yarns of the upper layer fabric, which are arranged in pairs above and below the machine direction yarns of the upper layer fabric, and the unit length of the machine direction yarns of the upper layer fabric. machine direction yarns arranged in a number less than the number of yarns per unit; every other machine direction yarn of the lower layer fabric is
Woven into machine weft yarn and plain weave structure of lower layer fabric,
Every other remaining machine direction yarn of the lower layer fabric is not interwoven with either the machine direction yarns of the upper layer fabric or the machine direction yarns of the lower layer fabric, and the machine direction yarns of the upper layer fabric and the machine direction yarns of the lower layer fabric are interwoven. between the machine direction yarns and extending substantially linearly in the machine direction; one of the two or three of the four machine direction yarns of the upper layer fabric; , is woven into a 1/1 plain weave structure with only the machine direction yarns of the upper layer fabric, and the remaining one thread among the machine direction yarns of the upper layer fabric is woven with the machine direction yarns of the upper layer fabric and the plain weave structure. In addition, the machine direction yarns of the upper layer fabric are located above the machine direction yarns of the upper layer fabric and are arranged in pairs above and below the machine direction yarns of the upper layer fabric. Where the directional yarns are located above the machine direction yarns of the bottom fabric, they pass under the machine direction yarns of the bottom fabric and under the machine direction yarns of the top fabric, thereby forming a connection between the top fabric and the bottom fabric. An endless two-layer molded fabric for papermaking. 2 The number of yarns in the machine weft direction of the lower layer fabric per unit length is arranged within the range of 1/2 to 1/3 of the number of yarns in the machine weft direction of the upper layer fabric per unit length. The endless two-layer molded fabric for papermaking according to item 1. 3. The endless two-layer formed fabric for papermaking according to claim 1, wherein the diameter of the machine weft direction yarns of the lower layer fabric is larger than the diameter of the machine weft direction yarns of the upper layer fabric. 4. The endless two-layer formed fabric for papermaking according to claim 1, wherein the machine direction yarns and machine weft direction yarns of the upper layer fabric and the machine direction yarns and machine weft direction yarns of the lower layer fabric are all made of polyester monofilament. . 5. According to claim 1, the machine direction yarns and machine weft direction yarns of the upper layer fabric and the machine direction yarns of the lower layer fabric are made of polyester monofilament, and the machine direction yarn of the lower layer fabric is made of polyamide monofilament. An endless two-layer molded fabric for paper making. 6. The endless two-layer formed fabric for papermaking according to claim 1, wherein the machine direction yarns of the lower layer fabric consist of an alternating arrangement of polyamide monofilaments and polyester monofilaments. 7 A machine in which the machine direction yarns, which are interwoven in a plain weave structure only with the machine direction yarns of the lower layer fabric, are made of polyamide monofilament and extend substantially linearly in the machine direction without being interwoven with the machine direction yarns of the lower layer fabric. The endless two-layer molded fabric for papermaking according to claim 1, wherein the directional threads are made of polyester monofilament. 8 Machine direction yarns interwoven with the machine direction yarns of the lower layer fabric in a plain weave structure are made of polyamide monofilament and are not interwoven with the machine direction yarns of the lower layer fabric and extend substantially linearly in the machine direction. The endless two-layer molded fabric for papermaking according to claim 1, wherein the yarn is made of polyester multifilament twisted yarn. 9. The endless two-layer formed fabric for papermaking according to claim 1, wherein polyamide monofilaments are used in all or every other yarn in the machine weft direction of the upper layer fabric. 10. The endless two-layer formed fabric for papermaking according to claim 1, wherein the machine direction threads of the upper layer fabric are made of polyamide monofilament.