[0001] The present invention relates to a papermakers fabric comprising a woven fabric having
at least one system of filament yarns extending in the machine direction interwoven
with at least one system of filament yarns extending in the cross machine direction,
each end of said fabric having an overlap portion folded back upon the fabric body
defining a fold line, with an area free of cross machine direction yarns adjacent
the fold line and with selected machine direction yarns having segments extending
from the fold line and defining a series of loops, each overlap portion being secured
to the fabric body by stitchings.
[0002] The series of loops of one end is introduced between the series of loops of the other
end to form a channel for receiving a pintle wire or joining wire. Such a papermakers
fabric is described in the document DE-A-2 064 085.
[0003] In the known papermakers fabric, machine direction yarns which are not forming loops
are cut near the fold line.
[0004] Additional cross machine direction yarns are interwoven with machine direction yarns
near the loops. Said additional yarns are stronger and more flexible than the original
cross machine direction yarns in order to prevent them from sliding into the loops.
[0005] But there is no real binding of the cross machine direction yarns which can therefore
slide into the loops. Further the ends of the cut machine direction yarns can slip
out the fabric and mark the paper.
[0006] The papermakers fabric according to the invention not having these drawbacks is characterized
in that remaining non-loop forming yarns are pulled from the area away from the loops
against the fold line and through the overlap portion.
[0007] The present invention relates also to a method of producing a low bulk pin-type seam
in a length of flat woven fabric for use with paper making equipment, said length
of flat woven fabric comprising a plurality of continuous filament warp yarns interwoven
with a plurality of pick yarns, by removing selected pick yarns from a portion of
the fabric to create a pick free area adjacent the end to define a fold line which
corresponds to the fabric end of one of the sides of the seam to be formed, the fold
line defining adjacent fabric body and fabric overlap portion on the fabric, by folding
the overlap portion at the fold line to overlap the fabric body to form a series of
loops, and by securing the overlap portion to the fabric body by stitchings, characterized
by
a) prior to folding, raising alternating selected non-loop forming warp yarns in the
pick free area from the plane of the fabric, while leaving alternating remaining loop
forming warp yarns within the plane of the fabric,
b) inserting a forming wire between the raised selected warp yarns and the remaining
warp yarns such that the forming wire overlies the remaining warp yarns,
c) folding the overlap portion and the loop forming yarns about the forming wire to
form said loops, and
d) prior to securing the overlap portion to the fabric body, pulling the selected
non-loop forming warp yarns from the pick free area away from the loops against the
fold line and through the overlap portion.
Fig. 1 is an orthographic projection of a fragment of a fabric end to be seamed in
accordance with the invention.
Fig. 2 is an orthographic projection of the fabric of Fig. 1 with a pick free area.
Fig. 3 illustrates the separation of warp yarns according to the invention.
Fig. 4 illustrates the insertion of a loop forming means according to the invention.
Fig. 5 illustrates the formation of a fold over or hem according to the invention.
Fig. 6 illustrates the pull through of selected warp yarns against the hem line according
to the invention.
Fig. 7 illustrates the fabric seam end after pull through of the selected yarns and
trimming of the hem.
Fig. 8 illustrates the fabric of Fig. 7 with beveled edges and stitches according
to the invention.
Fig. 9 illustrates an alternative embodiment according to the invention.
[0008] The present invention is directed to a fabric having a low bulk pin-type seam. The
seam is constructed by forming loops in each end of a flat woven papermakers fabric.
The loops are formed from machine direction yarns which are selected from a portion
of the fabric which had previously been freed of all cross machine direction yarns.
The fabric is folded back on itself in the manner of a hem and selected machine direction
yarns are pulled through the fabric to bind the fabric body and fold over together.
Both ends of the fabric are made similar and when mated together, the loops forming
yarns define a channel which receives the pin or pintle wire.
[0009] Although specific forms of the invention have been selected for illustration and
the following description will refer in specific terms to those drawings, this description
is not intended to limit the scope of the invention which is defined in the claims
appended hereto.
[0010] The invention will be set forth with references to the attached drawings, wherein
like numerals indicate like elements in all views. The following description is intended
to aid in an understanding of the invention and it is understood that the invention
may be utilized with weaves or fabrics not specifically described in detail.
[0011] Referring now to Fig. 1, there is shown a fragmentary view of one end of the fabric
2 which is to be seamed. The fabric 2 is woven in the usual manner with a plurality
of warp yarns or machine direction yarns interlacing with a plurality of pick or cross
machine direction yarns 6 and 8. The warp yarns are preferably monofilament or continuous
filament yarns, however, they may be spun yarns which are twisted or treated so as
to behave as a continuous or monofilament yarns. Additionally, it will be understood
that the warp yarns may be of any cross sectional shape, i.e. round, square, oval,
rectangular, etc., according to fabric design. Likewise, the pick yarns may be any
of the available yarns selected according to fabric design. As will be known to those
skilled in the art, the fragmentary view of the fabric 2 shown in Fig. 1 is a duplex
fabric having two pick systems, comprised of yarns 6 in one pick system and yarns
8 in the other pick system, interwoven with a single warp or machine direction system
4. As will also be known to those skilled in the art, the overall length of the fabric
prior to seaming is somewhat.longer than the length of the final seamed fabric in
order to provide the material necessary for fabric seaming and subsequent treatment.
While the fabric 2 may be cut to the predetermined width of the desired fabric, it
has been found that it is advantageous to have approximately 50 mm of additional width
in the unseamed fabric in order to facilitate the ease of seaming.
[0012] Generally, the fabric end is prepared for seaming by removing a plurality of picks
6 and 8 from a predetermined area of the fabric. The warp yarns which have been exposed
by the removal of the picks are then segregated into loop forming yarns and binder
yarns according to a predetermined pattern. A loop forming wire is inserted between
the warp yarns which will essentially separate the fabric into 2 levels. The forming
wire is located as close to the body of the fabric is as possible. The fabric is then
placed on a work table with the fabric faced down. The free end of the fabric is then
folded back toward the body of the fabric in the manner of a hem. The folding back
of the free end of the fabric thus produces a plurality of loops extending from the
fabric fold or hem line. The binder warp ends noted previously are then drawn back
into the folded over section of the fabric. After the binder yarns have been pulled
back into the fold over of the fabric, the fold over section of the fabric is cut
to width. Stitches are then placed in the seam area to additionally secure the fold
over and fabric together. The fold over is then trimmed or cut to length and beveled
or rounded as is known in the art.
[0013] With reference to Fig. 1, the preparation of one end of the fabric seam will be described
in detail. It will be remembered that the other end of the fabric is prepared in a
like manner. Selected picks are removed at an area in from the free end of the fabric
in order to provide sufficient material for the fold over section. In the preferred
embodiment, the pick removal area is approximately 125 mm from the free end of the
fabric. The picks to be removed, generally illustrated as 10 are removed in both the
face and back pick layers. Picks 10 are removed from the fabric for approximately
(10 mm) starting from the end of the fold area previously described. Thus, picks are
removed in the area between approximately 125 to 135 mm from the free end of the fabric,
this pick free condition is illustrated in Fig. 2 and generally identified as 12.
[0014] Referring now to Fig. 3, a tool 14 such as a long stem awl or scriber, is used to
separate pairs of the warp yarns 4. Alternating pairs of warp yarns 4(a) are raised
from the plane of the fabric using the tool 14, likewise, alternating pairs of warp
yarns 4(b) are left within the plane of the fabric, as illustrated in Fig. 3. The
operation of raising the warp yarns 4(a) out of the plane of the fabric is difficult
to illustrate, however, this will be known to those skilled in the art. As shown in
Fig. 3, after a number of the warp yarns 4(a) have been raised from the plane of the
fabric, a suitable needle or insertion tool 16 with a forming wire 18 attached is
inserted between the raised warp yarns 4(a) and the remaining warp yarns 4(b). Note
that since the warp yarns 4(b) have not been disturbed with respect to the plane of
the fabric, the forming wire when inserted will overlie the warp yarns 4(b). This
condition is illustrated graphically in Fig. 4. The forming wire 18 is positioned
as close to the body of the fabric as is reasonably possible. In this position the
forming wire 18 will be adjacent the fold line or hem line 19 as will be described
hereinafter. Warp yarns 4(a) will be binder yarns and warp yarns 4(b) will be loop
forming yarns.
[0015] After the fabric has been so prepared, the fabric is positioned on a work table with
the fabric face down. Due to the bulk and weight of the flat woven fabric, it has
been found advantageous to secure the fabric to the work table such as by tacking
or other securing means. With the fabric so positioned, the free end of the fabric
is then folded back over the body of the fabric. Once again, it has been found that
securing the free end by tacking or other means is advantageous.
[0016] With reference now to Fig. 5, there is shown the fabric (without the work table)
in the folded or hemmed condition just described. For purposes of clarity of illustration,
the fabric has been shown with only the loop forming warp yarns 4(b) extending from
the hem line 19 adjacent the forming wire 18. It will be understood that the warp
yarns 4(a) are still part of the fabric but they are not part of the loop forming
warps shown in Fig. 5. Also it should be remembered that warp yarns 4(a) are to become
the binding yarns which are tight against the fold or hem line and therefore would
not appear in the area of the loops in the final configuration.
[0017] After the fabric has been secured to a work surface and has been folded as indicated
in Fig. 5, the binder warp yarns 4(a), which are not part of the loop, are pulled
through the fabric. With reference to Fig. 6, it can be seen that the warp yarns 4(a)
can be pulled through the folded over portion or hem of the fabric. For purpose of
clarity, the yarns 4(a) are shown as the first yarns in the fabric, however, it will
be understood that the yarns 4(a) are spaced across fabric at selected locations.
The pulling of the warp yarns 4(a) through the fold of the fabric will serve to remove
the excess warp length of yarns 4(a) in the area of the loop formed by the yarns 4(b).
In pulling the warp yarns 4(a) through the fold over or hem it has been found beneficial
to tocate the outermost warp yarn and to begin pulling the slack out of the yarn created
by the fold over. The pull through then proceeds across the width of the fabric until
all of the binding yarns have had the slacks removed therefrom. While it is not necessary,
it has on occasion been found beneficial to spray the warp yarns to be pulled through
with a silicone lubricant. However, in using a silicone lubricant, care should be
exercised because an excess application of silicone lubricant has also been found
to create a sticky or tacky surface on the yarns which may actually hinder the pull
through. The binder yarns 4(a) are pulled through the fold over with sufficient force
to draw the fold over and body of the fabric into intimate contact. It has been found
in constructing the seam that the appearance of a ripple may be noted in the fabric
fold over or hem on the back of the seam. This ripple phenomenon has not been found
to be detrimental to the seam and in fact, it has been found to be a useful indicator
that the warp yarns have been pulled with sufficient force against the fold or hem
line. Thus, the ripple may be used as an indicator that the pull through has been
done correctly. The ripple is not always visible but can be felt with slight hand
pressure or the finger tips. The pull through of the binder yarns 4(a) which has just
been described should be completed so that the loops 24 of slack warp yarns are spaced
approximately 50 mm from the position where the loop yarns 4(b) enter the fold over.
By so spacing the loops 24, it is then possible to trim the fold over so that it may
be trimmed or cut at 28 approximately 25 mm from the point where the loop yarns enter
the fold over, see Fig. 7. As it will be recognized by those skilled in the art, the
cut edge 28 of the fold over is preferably beveled, see Fig. 8, to aid in the running
of the fabric on the papermaking machine.
[0018] The. fold over and fabric body are stitched together in the area adjacent the loops.
With reference to Fig. 8, in the preferred embodiment two rows of stitching 30 and
32 are utilized. The first row of stitching 30 is located approximately 5 mm from
the point where the loops 4(b) enter the fabric and a second row of stitching 32 is
placed approximately 15 mm from the first stitch. In applications where a smooth seam
surface is essential, it has been found to be beneficial to remove a face pick in
the position where the stitching 30 and 32 is to be located. If desired, the pick
may be removed both from the body of the fabric and the fold over of the fabric. In
this way, the stitching 30 and 32 will sink into the fabric and do not alter the surface
characteristics thereof. In addition, to preserving the surface characteristics of
the fabric, it is believed that the recessed stitching will not be subjected to excessive
wear. It will be understood by those skilled in the art that the selection of stitch
point location will be a matter of design choice and will vary accordingly. For example,
in a weave pattern such as shown in Figure 1, one stitch arrangement which has been
employed is to place the stitches at the fourth and thirteenth pick of one and at
the fourteenth and ninth pick of the other end. Once again the fabric design is free
to selected stitch points according to weave design.
[0019] With respect to Figure 9, there is illustrated an alternative embodiment which in
all respects not set forth hereinafter will be the same as the fabric illustrated
in Figure 4. In Figure 4, the forming wire 18 is positioned such that. the warps are
paired into alternating loop and binder yarns. At Figure 9, the forming wire 18 is
positioned such that the warp yarns are arranged according to the selected repeat
pattern. In this repeat pattern, the warp yarns are arranged as two binder, two loop,
three binder and one loop yarn per repeat. This repeat pattern provides approximately
25% more binder yarns per seam with and approximately 25% less loop forming yarns
per seam with. This alternative arrangement has been found to produce a seam which
is fully acceptable with respect to strength and performance and which provides additional
spacing between the loop forming yarns. The additional spacing between the loop forming
yarns has found to be of some benefit in manipulating and aligning the loops in the
actual seam formation process.
[0020] It will be recognized that many various repeat patterns will be possible with the
instant invention. The essential feature is that the repeat pattern selected provide
sufficient loop forming yarns to achieve the necessary tensile strength and maintain
the seam stability. Likewise, it is required that sufficient binder yarns be provided
to maintain the hem tightly and to assure the required tensile strength.
[0021] Seams according to the invention have been made in both single ply and multiply fabrics.
[0022] As noted previously, the fabric weave construction may be according to design selection.
[0023] It will be understood that the other or remaining end of the flat woven belt will
be prepared in the manner described above and that after such preparation, the two
ends many be mated so that the loops are interleafed and thereby define a channel
through which a hinge wire or pintle may be inserted to complete the pin seam.
[0024] It will be understood that no back weaving is required to form the loop and that
no additional clipper hooks or coils are in the insert seam.
1. A papermakers fabric comprising a woven fabric (2) having at least one system of
filament yarns (4a, 4b) extending in the machine direction interwoven with at least
one system of filament yarns (6, 8) extending in the cross machine direction, each
end of said fabric (2) having an overlap portion folded back upon the fabric body
defining a fold line (19), with an area (12) free of cross machine direction yarns
adjacent the fold line (19) and with selected machine direction yarns (4b) having
segments extending from the fold line (19) and defining a series of loops, each overlap
portion being secured to the fabric body by stitchings (30, 32), characterized in
that remaining non-loop forming yarns (4a) are pulled from the area (12) away from
the loops against the fold line (19) and through the overlap portion.
2. A papermakers fabric according to claim 1, characterized in that the number of
segments constituting the loops is approximately equal to one half of the total number
of machine direction yarns (4a, 4b).
3. A method of producing a low bulk pin-type seam in a length of flat woven fabric
(2) for use with paper making equipment, said length of flat woven fabric (2) comprising
a plurality of continuous filament warp yarns (4a, 4b) interwoven with a plurality
of pick yarns (6, 8, 10), by removing selected pick yarns (10) from a portion of the
fabric to create a pick free area (12) adjacent the end to define a fold line (19)
which corresponds to the fabric end of one of the sides of the seam to be formed,
the fold line (19) defining adjacent fabric body and fabric overlap portion on the
fabric, by folding the overlap portion at the fold line (19) to overlap the fabric
body to form a series of loops, and by securing the overlap portion to the fabric
body by stitchings (30,32), characterized by
a) prior to folding, raising alternating selected non-loop forming warp yarns (4a)
in the pick free area (12) from the plane of the fabric, while leaving alternating
remaining loop forming warp yarns (4b) within the plane of the fabric,
b) inserting a forming wire (18) between the raised selected warp yarns (4a) and the
remaining warp yarns (4b) such that the forming wire (18) overlies the remaining warp
yarns (4b),
c) folding the overlap portion and the loop forming yarns (4b) about the forming wire
(18) to form said loops, and
d) prior to securing the overlap portion to the fabric body, pulling the selected
non-loop forming warp yarns (4a) from the pick free area away from the loops against
the fold line (19) and through the overlap portion.
1. Gewebe (2) für die Papierindustrie mit mindestens einem Fadensystem (4a, 4b) in
Maschinenrichtung, das mit mindestens einem senkrecht zur Maschinenrichtung verlaufenden
Fadensystem (6, 8) verwoben ist, wobei jedes Ende des Gewebes (2) einen Überlappungsbereich
aufweist, der auf den Gewebekörper zurückgeschlagen ist und eine Falzlinie (19) definiert,
mit einer Zone (12) in der Nähe der Falzlinie (19), die frei von Fäden quer zur Maschinenrichtung
ist, und mit ausgewählten Fäden (4b) in Maschinenrichtung, die von der Falzlinie (19)
ausgehende Segmente besitzen und eine Reihe von Schlaufen definieren, wobei jeder
Überlappungsbereich durch Nähte (30, 32) auf dem Gewebekörper befestigt ist, dadurch
gekennzeichnet, daß verbleibende keine Schlaufen bildende Fäden (4a) von der Zone
(12) aus den Schlaufen heraus gegen die Falzlinie (19) und durch den Überlappungsbereich
gezogen werden.
2. Gewebe für die Papierindustrie nach Anspruch 1, dadurch gekennzeichnet, daß die
Anzahl von Segmenten, die die Schlaufen bilden, etwa gleich der Hälfte der Gesamtzahl
der Garnfäden (4a, 4b) in Maschinenrichtung ist.
3. Verfahren zur Herstellung eines Saums geringen Volumens vom Stifttyp in einer Länge
eines flachen Gewebes (2) zur Verwendung in einer Papierherstellungsanlage, wobei
diese Länge des flachen Gewebes (2) eine Vielzahl durchlaufender Kettfäden (4a, 4b)
aufweist, die mit einer Vielzahl von Schußfäden (6, 8, 10) verwoben sind, durch Entfernung
von ausgewählten Schußfäden (10) aus einem Bereich des Gewebes, um eine von Schußfäden
freie Zone (12) in der Nähe des eine zukünftige Falzlinie (19) definierenden Endes
entsprechend dem Gewebeende an einer der Seiten des zu bildenden Saums zu definieren,
wobei die Falzlinie (19) zwischen dem Gewebekörper und dem Überlappungsbereich liegt,
durch Falten des Überlappungsbereichs entlang der Falzlinie (19), um auf den Gewebekörper
umgeschlagen zu werden und eine Reihe von Schlaufen zu bilden, und durch Befestigung
des Überlappungsbereichs auf dem Gewebekörper mithilfe von Nähten (30, 32), gekennzeichnet
durch
a) das Anheben alternierender ausgewählter, keine Schlaufen bildender Kettfäden (4a)
in der schußfadenfreien Zone (12) von der Gewebeebene vor dem Falten, während die
verbleibenden alternierenden, die Schlaufe bildenden Kettfäden (4b) in der Gewebeebene
bleiben,
b) das Einfügen eines Formungsdrahts (18) zwischen die ausgewählten angehobenen Kettfäden
(4a) und die verbleibenden Kettfäden (4b) derart, daß der Formungsdraht (18) oberhalb
der verbleibenden Kettfäden (4b) liegt,
c) das Umschlagen des Überlappungsbereichs und der die Schlaufe bildenden Fäden (4b)
um den Formgebungsdraht (18), um die Schlaufen zu bilden, und
d) das Herausziehen der ausgewählten, nicht die Schlaufen bildenden Kettfäden (4a)
aus derschußfadenfreien Zone weg von den Schlaufen gegen die Falzlinie (19) und durch
den Überlappungsbereich vor der Befestigung der Überlappungsbereichs auf dem Gewebekörper.
1. Feutre pour machines à papier comprenant un feutre tissé (2) ayant au moins un
système de fils (4a, 4b) s'étendant dans la direction de la machine entretissé avec
au moins un système de fils (6, 8) s'étendant dans une direction perpendiculaire à
celle de la machine, chaque extrémité dudit feutre (2) ayant un ourlet replié sur
le corps du feutre et définissant une ligne de pliure (19) avec une zone (12) sans
fils s'étendant dans la direction perpendiculaire à celle de la machine et adjacente
à la ligne de pliure (19) et avec certains fils dans la direction de la machine ayant
des segments s'étendant à partir de la ligne de pliure et définissant une suite de
boucles, chaque ourlet étant fixé au corps du feutre par des points (30, 32), caractérisé
en ce que les fils (4a) restant qui net forment pas de boucles sont tirés de la zone
(12) à travers l'ourlet en les éloignant des boucles et en les mettant contre la ligne
de pliure (19).
2. Feutre pour machines à papier selon la revendication 1, caractérisé en ce que le
nombre de segments constituant les boucles est approximativement égal à la moitié
de la totalité des fils s'étendant dans la direction de la machine. (4a, 4b).
3. Procédé de fabrication d'une jonction à jonc de faible encombrement dans une longueur
de feutre plat tissé (2) utilisé dans un équipement de fabrication de papier ladite
longueur de feutre tissé plat (2) comportant plusieurs fils de chaîne continus (4a,
4b) entretissés avec plusieurs fils de trame (6, 8, 10), dans lequel on retire certains
fils de trame (10) d'une partie du feutre pour créér une zone (12) sans fils de trame
adjacente à l'extrémité pour définir une ligne de pliure (19) qui correspond à l'extrémité
du feutre d'un des côtés de la jonction à former, la ligne de pliure (19) définissant
sur le feutre un corps de feutre adjacent et un ourlet à replier sur le feutre et
on plie l'ourlet selon la ligne de pliure (19) pour recouvrir le corps du feutre pour
former une suite de boucles puis on fixe l'ourlet au corps du feutre par des points
(30, 32), caractérisé en ce que
a) avant de plier on soulève du plan du feutre les fils de chaîne alternés choisis
pour ne pas former de boucles (4a) dans la zone (12) sans fils de trame tandis qu'on
laisse les fils de chaîne alternés restants qui forment des boucles dans le plan du
feutre,
b) on insère un fil de formage (18) entre les fils de chaînes soulevés (4a) et les
fils de chaîne restants (4b) de façon que le fil de formage recouvre les fils de chaîne
restants (5b),
c) on plie l'ourlet et les fils formant les boucles (4b) autour du fil de formage
(18) pour former lesdites boucles et avant de fixer l'ourlet sur le corps du feutre,
d) on tire les fils de chaîne ne formant pas les boucles (4a) à travers l'ourlet à
partir de la zone sans fils de trame en les éloignant des boucles et en les mettant
contre la ligne de pliure (19).