KR20070006817A - Dryer fabric seam - Google Patents

Abstract

An industrial fabric is described which comprises a woven fabric body having opposing ends. The fabric repeating weave pattern includes at least two systems of vertically stacked machine direction warp yarns interwoven with at least one system of cross machine direction weft yarns. On each end of the fabric at least some of the warp yarns form a first set of loops each of which is at a first angle to the machine direction, at least some of the warp yarns form a second set of loops each of which is at a second angle to the machine direction and each of the second set of loops is substantially concentric with the first set of angled loops to provide double end loops which can be seamed by using a coil seam or a pin seam. This fabric structure has the advantage that it is possible to use all of the fabric warp yarns in the loops, thus significantly increasing the tensile strength of the seam. It also permits the fabrication of a flatter seam. This seam design is of particular use in dryer fabrics for a paper making machine. ® KIPO & WIPO 2007

Description

Dryer Fabric Fittings {DRYER FABRIC SEAM}

FIELD OF THE INVENTION The present invention relates to improved, particularly high loop density, back weave dryer fabric seams of coil or pin seams used to join ends of fabrics such as paper machines.

The woven fabrics used in the forming, pressing or drying sections of paper machines are usually produced as continuous strips which are converted into endless loops by the following three methods.

(a) a method of joining a permanent woven seam and an opposite end of a flat woven fabric as described by way of example in U.S. Patent No. 3,366,355,

(b) forming a small loop in the opposite end of the fabric to form a passage through which the pintle is inserted to form a hinged joint as a pin joint as described as an example in US Pat. No. 4,182,381, and placing the fabric on a paper machine Interdigitating these loop ends during installation to join opposite ends of the flat woven fabric,

(c) each of the two opposite ends of the fabric to form a passage through which the pintle is inserted to form a hinged joint as described by way of example in US Pat. Nos. 5,875,822, 6,065,505, 6,241,081 and 6,267,068. Forming a small loop in the joint, combining each of the two sets of loops with the helical coil, and interdigitating two coils attached to opposite fabric ends to join the opposite ends of the flat woven fabric.

The present invention relates to at least two of these methods, in particular to the last method. Joints of this type are well known, widely used, and coil types are common. In the fin and coil seams, the warp is used to form the desired loop by removing some weft from each of the fabric ends and weaving the exposed length of the warp back into adjacent warp passages within the fabric end. do.

Since many industrial fabrics are usually combined in a continuous loop according to the intended machine installation, the present invention relates to a textile industry fabric in which the coil seam is suitable. FIELD OF THE INVENTION The present invention relates to an industrial fabric having at least two warp layers in construction, wherein at least two clear layers of warp are placed one over the other in a repeating weaving pattern of the fabric, each one on one planar fabric surface. Warp yarns are in a stacked relationship with other warp yarns located on opposite planar surfaces of the fabric. Such fabrics are well known and are described in Lee's U.S. Pat. 5,411,062, 5,645,112 and 5,690,149. The invention applies to the weaving industrial fabric having two separate layers in the warp in the weaving pattern of the fabric as disclosed in Lee's patents, which is intended as a dryer fabric in a paper machine.

Because of their length, the dryer fabrics are almost always coupled to an endless loop on the dryer section of the paper machine, so the invention is particularly applicable to dryer fabrics, in particular to dryer fabrics in which coil or pin type seams are used. The invention applies in particular to two layers of fabrics commonly used as paper machine dryer fabrics.

Conventional joints provide, but are not limited to, the following disadvantages.

1) Due to the difficulty of interdigitating the loop or coil on the fabric end, during installation, the pintle is inserted into the loop or coil to close the seam;

2) fabric breakage caused by insufficient processing direction strength in the area of the seam, because it is used in the seam only in consideration of the warp ratio;

3) Marking of the wet paper web by the joint structure.

It is known that transverse seams are a potential weakness in fabrics, and seam breaks are common to all paper machines. It is highly desirable that the pin seam or coil seam having tensile strength properties in the processing direction of the fabric be provided in the body of the fabric itself adjacent or away from the seam. Most pin seams and coil seams are made by forming the required loop by using only half of the potentially available warp, while other warp is bent back around the weft and rewoven into the end of the fabric. Since the remaining 50% of the warp is not a load bearing member in the seam, the tensile strength of this seam cannot exceed 50% of the fabric tensile strength.

It is known to make coil seams by using more than 50% of the available warp to form the loop required to attach the spiral coil to the fabric end. The coils used are typically manufactured from monofilaments formed from thermoplastic polymers such as nylon, PPS or PEEK. In general, monofilaments have a substantially cross section, but other forms such as ovals or rectangles may be used as disclosed by way of example in US Pat. No. 5,875,822 to Farout. As the number of fabric warps used to provide the loop to attach the coil increases, the space that can be used to accumulate the interdigitation of the coil into the loop to form a seam increases the number of warp loops used to attach the coil. As a result of this reduction, the cross sectional area of the monofilament used to manufacture the coil should be reduced.

If the cross-sectional area of the monofilament used for the coil, or the cross-sectional shape of the monofilament used for the coil, or both are not converted to accumulate the increased number of loops used to attach the coil, the seam is difficult to assemble, and It is not soft enough to be non-marking. However, since the size of the monofilament used in the coil is reduced, the tensile strength of the seam also decreases and is also undesirable.

It is well known that the seams themselves, together with the two regions of the side where the warp yarn used to provide the loop are woven back to the fabric end, are not marked on the paper being made. Seam markings are generated in the dryer section by different drying rates which result in a difference in air permeability in the seam area compared to the rest of the fabric. The seam mark is also generated by excessive pressure on the wet paper web of any raised portion in the area adjacent to the seam that will weave the back side of the warp end used to provide the loop.

In general, the seams should only be made as small as possible compared to the body of the fabric in terms of both permeability, flexibility, fabric end thickness, and seam tensile strength.

Numerous fabric designs and seams for such fabric designs have been proposed.

In related patent groups, including U.S. Pat.Nos. 5,092,373, 5,411,062, U.S. Pat.No.35,966, U.S. Pat. Both of the seam structures used in such fabrics are disclosed. Although fabrics within the design range disclosed in Lee's patent have been used commercially, the seam structure has the drawback that only 50% of the warp yarns are used to make the loop required by the pin seam, as described above. Moreover, Lee's patents did not consider the use of coil joints.

Moreover, the advantage provided by Lee's patent is that the seam loops are easy to insert pintles parallel to the processing direction, but this is looped into the warp passages directly below the loop forming warp in the described stacking arrangement for the fabric. Only by reweaving the warp back and using the other warp for loops to obtain the space needed to interdigitate the loop, so when interference occurs, the non-loop forming warp bends back around the weft, Are rewoven into the ends of the.

In US Pat. No. 5,601,120 to Cookkart et al., The pintle seam structure is disclosed for a two layer fabric suitable for use in the dryer section of a paper machine. In the seam structure disclosed in this patent, the flat rectangular cross-sectional warp indicates a double layer loop consisting of a pair of warp yarns with one warp from the paper side layer of the fabric and the other warp from the fabric side layer of the fabric. It is used to In each loop, the processing side layer warp is bent back for reweaving to the fabric end relative to the first passage, and the paper side layer warp is processing side layer warp for reweaving to the fabric end relative to the second passage. Bends back around the outer perimeter of the inner loop. However, even if such double layer loops have increased strength, in the seam structure as described, only 50% of the stacked flat warp is used to represent the two layer loops. As the warp in the fabric is stacked vertically above each other as described, the loops must be woven backward into the passage of the warp just below the warp used to form the loop.

Pickers et al. US Pat. Nos. 6,065,505 and 6,267,068 disclose stitched spiral seams similar to coil seams when viewed visually on woven dryer fabrics. Seams of this type are generally used at the side edges of the dryer fabric to increase seam tensile strength. As mentioned above, the stitched helical seams are sewn in the processing direction on opposite ends of the fabric, thereby minimizing the tensile strength of the helical seams by utilizing all the processing direction warps to attach the spiral seams to the fabric ends. Stitched helical coils are held in place by at least one weft, and the warp yarns are weaved directly underneath themselves to maintain the laminated warp arrangement characteristics of suitable fabrics. The openings formed in the fabric by the warp yarns in this seam construction are substantially horizontal.

Holden's US Pat. No. 6,241,081 discloses a modified coil joint arrangement, which is held by both long and short loops formed at the warp ends. Weaving patterns are not provided with warps located in a stacked arrangement. Although the aspect of the seam disclosed by Holden is similar to the seam of the present invention, Holden does not disclose coil seams in multilayer fabrics of the type disclosed in the aforementioned patent.

SUMMARY OF THE INVENTION The present invention provides a seam structure with at least two layers of warp, in particular for industrial fabrics, such as papermaker's fabrics, which overcomes or minimizes the aforementioned disadvantages. In particular, the present invention provides a seam structure for industrial fabrics, in particular for dryer fabrics of multi-layer paper machines, where all fabric warps are used to make loops for seams.

In a first embodiment, the invention comprises a weaving main body having opposite ends, wherein the weaving direction warp is vertically laminated into at least two systems and the mutual weaving of cross weaving wefts into at least one system, On each end at least some warp forms a first set of loops, each at a first angle with respect to the machining direction, and at least some warp forms a second set of loops, each in the machining direction At a second angle with respect to the second set of loops, each of the second set of loops comprises an industrial fabric that is substantially concentric with the first set of angled loops to provide a double end loop.

The first set of angled loops and the second set of angled loops are preferably made in adjacent warp yarns.

More preferably the first set of angled loops and the second set of angled loops are made in adjacent warp yarns, with each set of loops being made within 50% of the warp yarns in the warp system.

Preferably, the first and second angles are similar.

Preferably the first and second angles are not in the same direction relative to the machining direction, whereas the first and second angles are relative to the machining direction.

At a pair of opposing fabric ends manufactured for the coil seam, the direction of the first and second angles relative to the machining direction is preferably selected to match the direction of the helical angle in the coil used to close the seam. .

In a second embodiment, the present invention is used for the cross section of a dryer of a papermaking machine, the papermaking fabric having a processing side, a paper side, and a processing direction, having opposite ends, each end including a joint loop. To

Wherein the fabric comprises a combination of a first set of monofilament warp yarns positioned in the processing direction, a second set of monofilament warp yarns positioned in the processing direction and at least one set of monofilament weft yarns positioned in a cross processing direction,

The two sets of warp and weft are mutually weaved in a repeating weaving pattern,

The first set of warps provides an exposed float on the paper side of the fabric,

The second set of warps provides an exposed float on the processing side of the fabric,

Each warp of the first set is interwoven with the weft to form a knuckle between the weft and the exposed float in the second set,

Each warp of the second set is interwoven with the weft to form a knuckle between the weft and the exposed float in the first set,

The first set of monofilament warp yarns is located in a woven pattern directly above the second set of monofilament warp yarns,

The first set of seam loops then consists of each exposed end of the first set of warp warped to form a first set of loops each at a first angle with respect to the machining direction,

The remainder of each exposed warp end is rewoven from the second set of warp to the next subsequent warp passage of the warp, correlating with the weaving pattern of the next adjacent warp passage,

The second set of seam loops consists of each exposed end of the second set of warp warped to form a second set of loops each at a second angle to the machining direction,

Each of the second set of loops is substantially concentric with that of the angled loop of the first set, and each of the exposed warp end ends subsequent from the first set of warp, while interacting with the weaving pattern of the fabric. Rewoven into warp passages.

In the context of the present invention, the following terms have the meanings given below.

The term "machine direction" means a direction parallel to or concentric with the direction in which the fabric moves during use, for example, in a paper machine.

The term "cross processing direction" means perpendicular to the processing direction, in a direction parallel or concentric with the surface of the fabric.

The term "warp passage" means a passage within a repeating weaving pattern occupied by a selected warp.

The term "float" means that the lengths of the warp yarns past or under the groups of wefts are not mutually nonwoven, and accordingly the term "float length" is expressed as a number indicating that a number of warp passes or is underneath. It means the length of the float.

The term "lamination" refers to a weaving pattern design that repeats such that warp yarns within each layer are positioned vertically above each other.

1 is a schematic cross-sectional view taken through two layers of fabric in a processing direction parallel to the warp yarn,

FIG. 2 is a schematic cross-sectional view taken through the end of the fabric in the processing direction parallel to the warp yarn showing the spiral coil entering the seam loop, FIG.

3 shows a paper side surface of a portion of the fabric shown in FIG. 2, FIG.

4 shows two fabric ends prepared for seam with two helical coils already interdigitated for insertion of the pintle to complete the seam;

Figure 5 shows the required pins for the pin seam entering the seam loop, which is a partial cross-sectional schematic perspective view of the end of the fabric in the processing direction parallel to the warp yarns.

The invention is explained in more detail as an embodiment with reference to the accompanying drawings.

First, in Figure 1, the fabric cross-section shown is taken in parallel to the warp yarns in the processing direction of the two-layer fabric structure according to the contents of the above patent. The fabric shown is commercially available but is a single example of a multilayer dryer fabric. The fabric shown is a two-layer fabric using two sets of warp yarns and one set of wefts, the design of which is also used in FIGS.

As can be seen in detail from FIG. 1, the fabric shown is a two-layer fabric in which a single set of wefts 3 and two sets of warp yarns 1, 2 are woven together. Warp passages occupied by warp yarns 1 and 2 are stacked on top of each other. Each passageway provides an exposed float in the paper side layer 4 and the processing side layer 5 of the fabric. Inside of this exposed float, the warp from the other surface of the fabric is interwoven with the weft such that it passes between the weft and the adjacent warp float. In addition, the paper side warp 2 passes between the weft 6 and the float 4 in the warp 1, while the processing side surface of the warp 1 has a float in the weft 7 and the warp 2 8) Pass through. This fabric structure is one in which the other is always stacked vertically up and down relative to one of the two blade threads 1, 2.

Figure 2 shows a cross section in the same direction as Figure 1 at the end of the fabric to make seams. FIG. 2 shows only the final few strands of weft in the fabric end, showing the initial portion of the warp passages suitable for reweaving the ends of the warp 1, 2 back to the fabric end. These passages are several centimeters in length, and each warp is woven backward in a pattern that repeats the weaving of the selected warp passages, respectively.

As can be seen in detail from FIG. 2, each of the warp yarns 1 passes over the weft yarns 10, passes under the weft yarns 10 and the warp yarns 2, and the warp yarns 2 again become the weft yarns 10. ) And the warp yarn (1). The seam loop is made from warp 1 to 1A and warp 2 to 2A. All the weft yarns need not necessarily have the same diameter, and although the weft yarns 10 are smaller than the weft yarns 10A, the weft yarns 10 and 10A may be opposite to each other.

The figure also shows a seam coil 11 coupled with two loops 1A and 2A, as indicated by the cut end 12 of the coil 11. It can be seen that all the warp direction warps are used to join the seam and the fabric end of the seam, and furthermore, the spiral coil 11 as used in the seam structure is formed in a hole formed in the space in the loops 1A and 2A. It can be seen that it is located. By weaving each set of warp yarns represented by warp yarns 1 and 2 into the warp passages immediately adjacent to the stacked warp yarns, the loops are made angled with respect to the processing direction. Then, when the seam is in use and tensioned, the two loops 1A and 2A are movable and occupy a small space. This provides a selection level for selecting the shape and transverse cross-sectional area of the monofilament warp yarn used to construct the spiral coil.

FIG. 3 shows in more detail the paper side surface of the fabric end shown to make the seam in FIG. 2, and this feature of the seam structure is shown in FIG. 3.

First, the loop 20 of the warp yarn 10 is formed around the outside of the loop of the warp yarn 2 and is small or largely concentric with it, even if the angle of the loop of the warp yarn 1 is relatively angled. There is an angle relative to the machining direction of. This is accomplished by reweaving the warp 1 into the path of the warp adjacent to the original passage, placing the warp 1 under the warp 2 to the processing side of the fabric. This location is shown in FIG. Similarly, the warp yarns 2 are rewoven into warp yarns adjacent to the original passage. By using a passage adjacent to the same side of the warp 1 passage and the warp 2 passage, all the loops are angled in the same direction relative to the processing direction.

Secondly, the adjacent warp passages above or below the warp 1 passage in FIG. 3 are selected to angle the loop of the warp 1 in either direction. This selection allows the warp loop to be registered as a loop of coil 11. This simplifies the insertion of the coil into the loop.

Third, it can be seen that the first angle with respect to the loop 1A of the warp yarn 1 and the second angle with respect to the loop 2 of the warp yarn 2 need not necessarily be the same. Moreover, as shown in FIG. 3, the angle with respect to the loop 1A is in a direction opposite to the machining direction shown by arrow A in FIG. 3. Moreover, it can be seen that the third angle, which is the angle of the double loops 1A and 2A, is not the same angle as the first or second angle. In addition, as shown in FIG. 3, the angle with respect to the loop 1A is in a direction opposite to the machining direction shown by arrow A in FIG. 3. Also, the third angle, which is the angle of the double loops 1A and 2A, is not equal to the first angle or the second angle.

4 shows a seam of the present invention made to have pintle wires inserted into two helical coils 11 and 12. These two coils are interdigitated into two sets of loops on two opposing fabric ends 21, 22 fabricated as shown in FIGS. Insertion of the pintle along the line, shown approximately X-X, closes the seam.

Figure 5 shows one fabric end made in accordance with the present invention for a seam using a pin seam instead of a coil seam. The fabric shown is the same as in FIG. 1, and in FIG. 5 it can be seen that a pin 25 for the seam is added in such a way that two sets of loops are arranged. The warp yarn 1 is provided with a loop 1A around the pins 25 and rewoven at the fabric ends in the adjacent warp passages 1B. Similarly, warp 2 is provided with loops 2A around pin 25 and rewoven at the fabric ends in adjacent warp passages 2B.

When the pin seam is used as shown in Figure 5, it is advantageous to select the first and second angles for the loop on one end of the fabric to match the corresponding angle for the loop on the other second fabric of the fabric, which is This is because the interdigitation of the two fabric ends for the insertion of seam pins into the digitized loop is easy.

In the fabrics shown in Figs. 1-4, flat warp is used, as described in the above-mentioned Li patent.

As mentioned above, the joint structure of the present invention provides improved tensile strength as compared to conventional joints in primarily similar fabrics due to the use of all warp yarns. In addition, the use of a double loop having one warp inside the other warp allows each loop to bring the coil's angular orientation closer. This may platter the area closer to the seam, resulting in much less wet paper webs. Second, by placing two warps more or less concentrically in each loop, more space is provided between the loops for the seam coils and is closer in size to the monofilament warp used for warp in the fabric. Allows use of wider monofilament warp for the coil. Or this allows the use of a somewhat wider monofilament warp in the fabric. The net effect on this is to increase the tensile strength of both the seam and the fabric of the fabric, and to increase the active life of the fabric.

Fabrics according to a preferred embodiment of the present invention as described above is not limited to the above embodiment, for example, in Figures 3 and 4, the coil shown is not circular, but in a somewhat deflected cross-sectional shape Coils of this type may also be flat and have the advantage of reducing the thickness of the seam, thereby ensuring the flexibility of the paper-side surface in the seam area, as claimed in the following claims. Without departing from the scope of the present invention, any person having ordinary skill in the art will have the technical spirit of the present invention to the extent that various modifications can be made.

Claims (9)

In industrial fabrics, The woven body has opposing ends, including a weaving warp yarn that is vertically stacked in at least two systems and interweaving of cross weaving wefts in at least one system, On each end of the fabric at least some warp forms a first set of loops, each at a first angle with respect to the processing direction, and at least some warp forms a second set of loops, each processed Wherein the industrial fabric is at a second angle with respect to the direction and each of the second set of loops is substantially concentric with the first set of angled loops to provide a double end loop. A papermaking fabric, which is used for the cross section of a paper machine, has a processing side, a paper side, and a processing direction, and has opposite ends, each end including a joint loop, The fabric is A first set of monofilament warps positioned in the machining direction, A second set of monofilament warps positioned in the machining direction, Consisting of a combination of at least one set of monofilament wefts positioned in the cross processing direction, The two sets of warp and weft are mutually weaved in a repeating weaving pattern, The first set of warps provides an exposed float on the paper side of the fabric, The second set of warps provides an exposed float on the processing side of the fabric, Each warp of the first set is interwoven with the weft to form a knuckle between the weft and the exposed float in the second set, Each warp of the second set is interwoven with the weft to form a knuckle between the weft and the exposed float in the first set, The first set of monofilament warp yarns is located in a woven pattern directly above the second set of monofilament warp yarns, The first set of seam loops then consists of each exposed end of the first set of warp warped to form a first set of loops each at a first angle with respect to the machining direction, The remainder of each exposed warp end is re-woven from the second set of warp to the next subsequent warp passage of the warp, correlating with the weaving pattern of the next adjacent warp passage, The second set of seam loops consists of each exposed end of the second set of warp warped to form a second set of loops each at a second angle to the machining direction, Each of the second set of loops is substantially concentric with that of the angled loop of the first set, and the remainder of each exposed warp end is next from the first set of warp, while interacting with the weaving pattern of the fabric. Paper fabrics re-woven into the subsequent warp passages. The method according to claim 1 or 2, The first set of angled loops and the second set of angled loops are made in adjacent warp yarns. The method according to claim 1 or 2, The first set of angled loops and the second set of angled loops are made in adjacent warp yarns, each set of loops being made within 50% of the warp yarns in the warp system. The method according to claim 1 or 2, The first, second and third angles are similar fabrics. The method according to claim 1 or 2, The first angle and the second angle are not in the same direction relative to the processing direction. The method according to claim 1 or 2, The first angle and the second angle are relative to the processing direction the fabric. The method according to claim 1 or 2, At a pair of opposing fabric ends manufactured for the coil seam, the directions of the first, second and third angles relative to the machining direction are selected to match the direction of the helical angle in the coil used to close the seam. Fabric. The method according to claim 1 or 2, At a pair of opposing fabric ends manufactured for the pin seam, the directions of the first, second and third angles relative to the processing direction on each fabric end are interdigitated of two sets of loops on the fabric end. Fabric selected to facilitate presentation.

Images