U.S. patent application number 12/591704 was filed with the patent office on 2010-10-07 for industrial two-layer fabric.
This patent application is currently assigned to NIPPON FILCON CO., LTD.. Invention is credited to Ikuo Ueda.
Application Number | 20100252137 12/591704 |
Document ID | / |
Family ID | 41650076 |
Filed Date | 2010-10-07 |
United States Patent
Application |
20100252137 |
Kind Code |
A1 |
Ueda; Ikuo |
October 7, 2010 |
INDUSTRIAL TWO-LAYER FABRIC
Abstract
A two layer fabric has first, second, third and fourth upper
side wefts contiguously and repeatedly arranged. Each of three
contiguously arranged warps forms a knuckle over second, over
third, and over second upper side wefts respectively to form a
separation portion. At both sides of the separation portion, both
the second and third upper side wefts form a float portion by
passing over two or more warps. Adjacent to the float portion, one
warp passes over the second and third upper side wefts successively
and one or two warps adjacent thereto pass over the second or the
third upper side weft to form an approach portion where the second
and third upper side wefts approach. Crimp portions are formed to
sandwich the separation portion where the first and fourth upper
side wefts pass over warps which are common to those of the
separation portion.
Inventors: |
Ueda; Ikuo; (Shizuoka,
JP) |
Correspondence
Address: |
RADER FISHMAN & GRAUER PLLC
LION BUILDING, 1233 20TH STREET N.W., SUITE 501
WASHINGTON
DC
20036
US
|
Assignee: |
NIPPON FILCON CO., LTD.
Inagi-shi
JP
|
Family ID: |
41650076 |
Appl. No.: |
12/591704 |
Filed: |
November 30, 2009 |
Current U.S.
Class: |
139/413 |
Current CPC
Class: |
D21F 1/0036
20130101 |
Class at
Publication: |
139/413 |
International
Class: |
D03D 11/00 20060101
D03D011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 28, 2008 |
JP |
2008-303909 |
Claims
1. An industrial two-layer fabric comprising: upper side warps that
are woven with upper side wefts configured to constitute an upper
layer; lower side warps that are woven with lower side wefts
configured to constitute an lower layer; and binding yarns that
weave the upper layer and the lower layer, the binding yarns being
either warp binding yarns or weft binding yarns, wherein: a first
upper side weft, a second upper side weft, a third upper side weft,
and a fourth upper side weft are arranged contiguously and
repeatedly; the second upper side weft and the third upper side
weft form a separation portion, a floating portion and an approach
portion; each of the first upper side weft and the fourth upper
side weft form a crimp portion; at the separation portion, each of
a first set of three contiguously arranged warps, that include the
upper side warp or the warp binding yarn, or alternatively the
upper side warp and the warp binding yarn, forms a one weft long
knuckle over the second upper side weft, a one weft long knuckle
over the third upper side weft, and a one weft long knuckle over
the second upper side weft, respectively whereby the second upper
side weft is separated from the third upper side weft; at the
floating portion, the second upper side weft and the third upper
side weft are arranged to pass over a second set of two or more
warps that include the upper side warp or the warp binding yarn, or
alternatively the upper side warp and the warp binding yarn, two of
the second sets of warps are arranged adjacent to both sides of the
first set of the warps to form two floating portions at both sides
of the separation portion; at the approach portion, which is
arranged adjacent to and between the two floating portions, a first
one of a third set of warps, which is either an upper side weft or
a warp binding yarn, passes over the second upper side weft and the
third upper side weft successively and a second one or two of the
third set of warps arranged adjacent to the first one of the third
set of warps pass over either one of the second upper side weft or
the third upper side weft so that the second upper side weft and
the third upper side weft approach to each other; and at the crimp
portion, each of the first upper side weft and the fourth upper
side weft passes over at least the first set of warps, the crimp
portions formed by the first and fourth upper side wefts sandwich
the separation portion.
2. The industrial two-layer fabric according to claim 1, wherein,
in a repeating unit, the upper layer and the lower layer are woven
with one selected from a group consisting of one warp binding yarn,
one weft binding yarn, a pair of warp binding yarns and a pair of
weft binding yarns.
3. The industrial two-layer fabric according to claim 1, wherein
the three warps of the first set of warps at the separation portion
are any one of a combination of only upper side warps, a
combination of only warp binding yarns, and a combination of an
upper side warp or upper side warps and a warp binding yarn or warp
binding yarns.
4. The industrial two-layer fabric according to any one of claims
1, wherein the upper side wefts are composed of repetition of the
first upper side weft, the second upper side weft, the third upper
side weft, and the fourth upper side weft which are arranged
contiguously.
5. The industrial two-layer fabric according to any one of claims
1, wherein between the fourth upper side weft and the first upper
side weft arranged subsequent thereto in a warp direction, a fifth
upper side weft or a plurality of the fifth upper side wefts are
arranged.
Description
CROSS-REFERENCES TO RELATED APPLICATION
[0001] This application claims priority from Japanese Patent
Application Serial No. 2008-303909 filed Nov. 28, 2008, the
contents of which are incorporated herein by reference in its
entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an industrial two-layer
fabric suited for use in the manufacture of paper or nonwoven
fabric requiring a uniform water drainage property, dehydration
property, breathability, supporting property of articles to be
conveyed, and the like.
[0004] 2. Description of the Related Art
[0005] Fabrics made by weaving warps and wefts are used widely for
industrial fabrics and, for example, papermaking fabrics, conveying
belts, and filter cloths. They are required to have fabric
properties suited for using purposes or using environments.
Requirements for papermaking fabrics used in a papermaking water
removal step from raw materials by utilizing meshes of the fabrics
are especially strict.
[0006] Such fabrics are required to have, for example, excellent
surface smoothness so as not to easily transfer the fabric's wire
mark to the supported paper, a dehydration property to enable
complete and uniform removal of excess water contained in the raw
materials, sufficient rigidity and wear resistance to enable
suitable use of the fabric even under severe environments, and a
capacity to retain conditions necessary for making excellent paper
for a long period of time. Fabrics are also required to have a
fiber supporting property, capacity to improve a papermaking yield,
size stability, traveling stability, and the like. The demand for
papermaking fabrics has become severer with a recent increase in
the speed of papering machines.
[0007] Among industrial fabrics, papermaking fabrics must satisfy
the most severe requirements so that a description of them will
promote understanding of the requirements for most of the
industrial fabrics and solutions thereof. Therefore, the
papermaking fabrics will hereinafter be described as one
example.
[0008] With a recent increase in the speed of the papermaking
machine, industrial fabrics are required to have a particularly
excellent dehydration property and surface smoothness. Although
necessary dehydration characteristics differ, depending on the
machine or product to be manufactured using the fabric, a
dehydration property and fiber supporting property are essential
conditions for any product. With recent increased use of waste
paper containing many minute fibers, much importance has been given
to the fiber supporting property. In addition, the fabrics are
required to have an excellent dehydration property because sheet
formation using minute fibers leads to deterioration in dehydration
property.
[0009] In papermaking fabrics, it is the common practice to carry
out centrifugation, press dehydration and the like by making use of
meshes of the fabrics. In order to achieve sufficient water
dehydration, suction dehydration from the backside surface of the
meshes is also carried out. Necessary characteristics such as fiber
supporting property and dehydration property have a great influence
on the operation efficiency and running cost.
[0010] Papermaking raw materials are supplied onto a wire running
from a head box so that fibers tend to be oriented in a machine
direction. In order to improve the fiber supporting property, it is
recommended to form a fabric having a fine surface and a weft long
crimp structure. This is because if fibers oriented in a machine
direction are received by a warp long crimp structure, the fibers
tend to drop off between warps.
[0011] U.S. Pat. No. 5,641,001 discloses a fabric for satisfying
both requirements, that is, the fiber supporting property and
dehydration property.
[0012] This fabric has an additional weft of a small diameter
between wefts. FIG. 8 of U.S. Pat. No. 5,641,001 shows a plan view
of the surface of the fabric in which additional wefts that extend
in a cross oblique direction are arranged. Since additional wefts
of a small diameter are placed between wefts, the fabric is
excellent in surface smoothness, fiber supporting property, and
dehydration property.
SUMMARY OF THE INVENTION
[0013] The fabric has, however, portions where mesh spaces are
ensured and also portions where wefts and additional wefts approach
to each other. Such portions where yarns approach each other cannot
provide sufficient dehydration, leading to uneven thickness of
paper.
[0014] An object of the present invention is to provide an
industrial two-layer fabric having a sufficient and uniform
dehydration property and therefore capable of overcoming a partial
dehydration shortage and at the same time, having an excellent
fiber supporting property and surface smoothness.
[0015] One of the greatest characteristics of the industrial
multilayer fabric of the invention is that the fabric has
alternately, in a cross direction, a portion where two adjacent
wefts separate from each other and a portion where they approach
each other. Even at the portion where yarns approach each other, a
three-dimensional space (dehydration space) is formed in an oblique
direction due to a height difference between warps and wefts. This
enables to increase the shooting count of wefts so that the
resulting fabric has improved surface property and fiber supporting
property.
[0016] With a view to overcoming the above problem, the present
inventors have adopted the following constitutions.
[0017] There is provided an industrial two-layer fabric having
upper side warps to be woven with upper side wefts, lower side
warps to be woven with lower side wefts, and binding yarns for
weaving an upper layer and a lower layer, wherein:
[0018] a first upper side weft, a second upper side weft, a third
upper side weft, and a fourth upper side weft are arranged
contiguously;
[0019] three contiguously arranged warps form knuckles
corresponding to one weft over the second upper side weft, the
third upper side weft, and the second upper side weft, respectively
to constitute a separation portion in which the second upper side
weft is separated from the third upper side weft;
[0020] on both sides of the separation portion, the second upper
side weft and the third upper side weft form floating portions
passing over two or more upper side warps or warp binding yarns,
respectively;
[0021] adjacent to and between the two floating portions, one warp
passes over the second upper side weft and the third upper side
weft successively and one or two warps on one side or both sides
thereof pass over either one of the second upper side weft or the
third upper side weft to form an approach portion in which the
second upper side weft and the third upper side weft approach to
each other; and
[0022] at positions sandwiching, in a machine direction, the second
upper side weft and the third upper side weft at the separation
portion, the first upper side weft and the adjacent fourth upper
side weft are arranged to pass over a plurality of the upper side
warps or warp binding yarns to form a crimp portion.
[0023] There is also provided the industrial two-layer fabric as
described above, wherein the upper layer and the lower layer are
woven with one warp binding yarn or weft binding yarn or a pair of
two warp binding yarns or a pair of two weft binding yarns.
[0024] There is also provided the industrial two-layer fabric as
described above, wherein the contiguously arranged three warps
constituting the separation portion are any one of a combination of
only upper side warps, a combination of only warp binding yarns,
and a combination of upper side warp(s) and warp binding
yarn(s).
[0025] There is also provided the industrial two-layer fabric as
described above, wherein the upper side wefts are composed of
repetition of the first upper side weft, the second upper side
weft, the third upper side weft, and the fourth upper side weft
which have been arranged contiguously.
[0026] There is also provided the industrial two-layer fabric as
described above, wherein between the fourth upper side weft and the
adjacent first upper side weft arranged subsequent thereto to the
warp direction, one additional upper side weft or a plurality of
additional upper side wefts are arranged.
[0027] The fabric of the invention is a two-layer fabric having, as
constituent yarns, upper side warps to be woven with upper side
wefts, lower side warps to be woven with lower side wefts, and
binding yarns for weaving an upper layer and a lower layer. It is
woven with one warp binding yarn or weft binding yarn, or a pair of
two warp binding yarns or a pair of two weft binding yarns.
[0028] Between two wefts adjacent to each other, there is a
separation portion in which they separate from each other and an
approach portion in which they approach each other. These two wefts
have therein a separation portion, a floating portion, an approach
portion, a floating portion, and a separation portion in the order
of mention. Thus they have both the separation portion and the
approach portion.
[0029] The upper side wefts constituting the fabric of the
invention have at least a first upper side weft, a second upper
side weft, a third upper side weft, and a fourth upper side weft
that are arranged contiguously. This order is repeated, for
example, as follows: first, second, third, fourth, first, second,
third, and fourth upper side wefts.
[0030] In the structure of the separation portion, each of three
contiguously arranged warps form one-weft-long knuckles over the
second upper side weft, over the third upper side weft, and over
the second upper side weft, respectively, in the order of mention.
At the separation portion, the second and third wefts are separated
in a machine direction so that spaces for separation are necessary.
It is therefore necessary to have the first and fourth upper side
wefts form crimps of passing over a plurality of warps (at least
three contiguously arranged warps above) to facilitate movement of
the first upper side weft and the fourth upper side weft at places
adjacent to the separation portion. The crimp portion does not
interrupt widening of the second and the third upper side wefts for
forming the separation portion, because it has no weaving position
and therefore it helps the first and fourth upper side wefts move
easily. To the contrary, if the first and fourth upper side wefts
are woven at the both sides of the separation portion to form such
as a plain weave design, firmly-woven warps and wefts interfere the
transfer of the first and fourth upper side wefts and prevent
widening of the second and third upper side wefts in a machine
direction at the separation portion.
[0031] The second upper side weft has a design in which it passes
under a first warp, over a second warp, and under a third warp at
the separation portion. Although the second warp lies under a weft
crimp, the two first and third warps are woven with the second
upper side weft so that they tend to gather together, resulting in
close contact of three warps constituting the separation
portion.
[0032] On both sides of the separation portion, both the second
upper side weft and the third upper side weft form a crimp passing
over two or more warps on each side of the separation portion,
thereby forming a floating portion adjacent to the separation
portion. Then, adjacent to the floating portion, a design is formed
in which one warp passes over the second upper side weft and the
third upper side weft successively and one or two warps adjacent to
the above-mentioned warp on one or both sides passes over either
one of the second upper side weft or the third upper side weft. As
a result, an approach portion is formed in which the second upper
side weft and the third upper side weft approach each other.
[0033] The floating portions are necessary for facilitating the
second and third upper side wefts, which have widened their space
at the separation portion, to approach each other (to transfer) at
the approach portion.
[0034] The fabric of the invention has thus a structure of a
portion where two adjacent upper side wefts separate from each
other and a portion where they approach to each other appear
alternately.
[0035] The structure of three warps constituting the separation
portion will next be described referring to FIG. 1. In the
separation portion, knuckles of the first warp and the second warp
are arranged in an oblique relation and knuckles of the second and
the third warps are also arranged in an oblique relation. Due to
repulsion between the knuckles, the second upper side weft and the
third upper side weft tend to separate from each other.
[0036] As illustrated in FIG. 1, warps 5, 6 and, 7 form knuckles on
the wefts 2, 3, and 2 in the order starting from the left. First,
an action to gather the warps 5, 6, and 7 together will be
described. The weft 3 is woven with the warp 5 and the warp 7 so
that in spite of presence of the warp 6 therebetween, they gather
together. The three warps therefore constitute a structure in which
they have gathered together.
[0037] Next, an action to separate the weft 2 from the weft 3 will
be described. Attention is paid to the intersections formed by four
yarns, that is, wefts 2 and 3 and warps 5 and 6.
[0038] The warp 5 is pushed upward at a confounding portion where
it passes over the weft 2 and forms a peak, while it forms a valley
at confounding portions on both sides thereof where it passes under
the wefts 1 and 3. The warp 6 is pushed upward at a confounding
portion where it passes over the weft 3 and forms a peak, while it
forms a valley at confounding portions on both sides thereof where
it passes under the wefts 2 and 4. In such a manner, at four
intersections made of two adjacent warps and two adjacent wefts,
the warps and wefts are arranged upside down, whereby the warp at
the valley moves to a direction away from the peak (in the
direction of an arrow in FIG. 1). As a result, the knuckle of the
warp 5 on the weft 2 moves downward in this drawing, while the
knuckle of the warp 6 on the weft 3 moves upward in this drawing.
They move so as to separate from each other and the wefts 2 and 3
woven with them also move to separate from each other.
[0039] Similarly, attention is paid to intersections of four yarns,
that is, wefts 2 and 3 and warps 6 and 7. The warp 6 is pushed
upward at a confounding portion where it passes over the weft 3 and
forms a peak, while it forms a valley at confounding portions on
both sides thereof where it passes under the wefts 2 and 4. The
warp 7 is pushed upward at a confounding portion where it passes
over the weft 2 and forms a peak, while it forms a valley at
confounding portions on both sides thereof where it passes under
the wefts 1 and 3. In such a manner, at four intersections made of
two adjacent warps and two adjacent wefts, the warps and wefts are
arranged upside down, whereby the warp at the valley moves to a
direction away from the peak (in the direction of an arrow in FIG.
1). As a result, the knuckle of the warp 7 on the weft 2 moves
downward in this drawing, while the knuckle of the warp 6 on the
weft 3 moves upward in this drawing. They move so as to separate
from each other and the wefts 2 and 3 woven with them also move to
separate from each other.
[0040] As described above, a force acts to separate between the
wefts 2 and 3 at two positions, that is, the warps 5 and 6 and the
warps 6 and 7 so that the separation portion is formed. Moreover,
there are the wefts 1 and 4 that form a long crimp on both sides in
the separating direction. At weaving portions of warps and wefts,
they are interwoven with each other so that transfer (or movement)
does not occur easily. At a long crimp structure where warps and
wefts are simply overlapped with each other, on the other hand,
their transfer occurs relatively easily. When such an easily
movable weft exists on the side to which the wefts 2 and 3 will
move, the wefts 1 and 4 transfer in association with the movement
of the wefts 2 and 3. As a result, the separation portion at which
two wefts separate from each other is formed.
[0041] With regard to the term "long crimp" as used herein, the
wefts 1 and 4 are required to have a design in which they pass over
at least the warps 5, 6, and 7 constituting the separation portion
in order to prevent formation of their knuckles on the warps
constituting the separation portion.
[0042] Next, the contiguously arranged warps for constituting the
separation portion in the fabric of the invention will be
described. The contiguously arranged three warps are composed of,
for example, one upper side warp and two warp binding yarns, which
means one warp pair (a pair of an upper side warp and a lower side
warp) and one warp binding yarn pair; two upper side warps and one
warp binding yarn, which means two warp pairs and one warp binding
yarn pair, or three upper side warps adjacent to each other, which
means three warp pairs. When three warps have a warp binding yarn
as one of constituent yarns, they may be two columns (one warp pair
and one warp binding yarn or one warp binding pair) or three
columns (two warp pairs and one war binding yarn pair, or three
warp pairs) in a design diagram or in a repeating unit.
[0043] In the case of three warps composed of three warp pairs, the
separation portion widens in the weft direction, causing a decrease
in the length of the floating portion. In this case, a uniform and
good dehydration property, which is an object of the invention, may
sometimes be difficult to attain due to a decrease in the degree of
separation and approach of wefts. This problem can however be
overcome by increasing the length of the floating portion.
[0044] It is preferred to constitute the separation portion from
three warps composed of two pairs, that is, a warp pair and a warp
binding yarn pair or three warps composed of two warp binding pairs
as illustrated in FIGS. 6A through 6F. FIGS. 6A and 6B show a pair
of upper side warp u and a lower side warp d, and another pair of
upper side warp u and a binding yarn B. FIG. 6C shows two pairs of
an upper side warp and a binding yarn. FIGS. 6D and 6E show a pair
of binding yarns and another pair of an upper side warp and a lower
side warp. FIG. 6F shows a pair of upper side warp and a binding
yarn and another pair of two binding yarns. In FIGS. 6D through 6F,
the warp binding yarn (B) and another warp binding yarn (b)
alternately form knuckles over either the second upper weft or the
third upper weft. FIG. 6G shows three pairs of an upper side warp
and a lower side warp. FIG. 6H shows three pairs of a binding yarn
and a lower side warp. FIG. 6I shows two pairs of upper side warp
and lower side warp and one pair of a binding yarn and a lower side
warp. FIG. 6J shows two pairs of a warp binding yarn and a lower
side warp, and one pair of an upper side warp and a lower side
warp. It is to be noted that a bold frame in FIGS. 6A-6J indicates
the site where the second warp knuckle (center knuckle) is
located.
[0045] In order to form the separation portion and the approach
portion successively from two wefts, it is necessary that the
structure between them should be a floating portion having no
weaving positions. At the floating portion, a weft is required to
have a design in which it passes over two or more warps. The term
"two or more warps" as used herein means two or more warp
pairs.
[0046] As described above, the floating portion has a structure
facilitating movement of yarns. A weaving position should not be
formed between the separation portion having a wide space and the
approach portion where yarns approach to each other in order to
facilitate movement from the separation portion to the approach
portion. Formation of this floating portion is a requirement for
the formation of both the separation portion and the approach
portion.
[0047] At the approach portion, there is a portion where one warp
passes over both the second upper side weft and the third upper
side weft so that they approach each other. A warp adjacent to the
above-mentioned warp has a design in which it passes over either
one of the second upper side weft or the third upper side weft. At
a portion where a warp passes over one weft, the weft is drawn into
the layer to decrease the height of the knuckle of the warp.
[0048] It cannot be denied that the approach portion becomes
inferior in dehydration property and breathability because the
number of yarns in the approach portion is greater than that in the
separation portion. If yarns constituting the approach portion are
different in height as in the invention, however, an oblique water
drainage space is formed so that the dehydration property is not
impaired even if the meshes on the surface are clogged.
[0049] The approach portion may employ a design in which one warp
passes over the second upper side weft and the third upper side
weft successively and another one warp adjacent to the
above-mentioned warp on one side passes over one of the second
upper side weft or the third upper side weft. FIGS. 5A through 5D
show these examples wherein the warps are upper side warps. FIGS.
5K through 5R are also these examples wherein the warps are an
upper side warp and a warp binding yarn. The approach portion may
employ another design in which one warp passes over the second
upper side weft and the third upper side weft successively and two
warps adjacent to the above-mentioned warp on one side or both
sides pass over one of the second upper side weft or the third
upper side weft. FIGS. 5E through 5J show these examples. In
particular, a design in which one warp passes over both the second
upper side weft and the third upper side weft and a warp adjacent
to the above-mentioned warp passes over either one of the second
upper side weft or the third upper side weft is preferred (see
FIGS. 5A-5D or FIGS. 5K-5R). An arrangement order at the approach
portion may be selected freely. Warps constituting the approach
portion may be either upper side warps or warp binding yarns.
[0050] As stated above, examples of the approach portion are
illustrated in FIGS. 5A-5R. Similar to FIGS. 6A-6J, a mark "x"
indicates that an upper side warp (u) lies over an upper side weft
to form a knuckle; and a mark ".diamond-solid." indicates that a
warp binding yarn (B or b) lies over an upper side weft to form a
knuckle. Thus, the approach portion may be formed of three warps.
At a blank box, an upper side weft runs under a warp. No particular
limitation is imposed on the design insofar as one warp passes over
two wefts and other one or two warps form more knuckles over either
one of the second upper side weft and the third upper side weft.
The warp may be either an upper side warp (u) or a warp binding
yarn (B or b).
[0051] Warps forming the upper layer of the fabric of the invention
are upper side warps. In the case of a warp-binding triple weave,
warp binding yarns as well as upper side warps serve as constituent
yarns.
[0052] The upper layer and the lower layer are woven with one warp
binding yarn or weft binding yarn, or a pair of two warp binding
yarns or two weft binding yarns. At positions where an upper side
warp and a lower side warp vertically overlap with each other, they
form an upper/lower warp pair. When a warp binding yarn exists, it
forms a warp binding yarn pair selected from a pair of two warp
binding yarns, a pair of an upper side warp and a warp binding
yarn, and a pair of a lower side warp and a warp binding yarn.
Alternatively, the warp binding yarn may be placed singly without
forming a pair.
[0053] In the fabric of the invention, the first upper side weft,
the second upper side weft, the third upper side weft, and the
fourth upper side weft are arranged contiguously. The second upper
side weft and the third upper side weft are substantially yarns for
constituting the separation portion and the approach portion, while
the first upper side weft and the fourth upper side weft are yarns
acting to form the separation portion. The presence of at least
these four wefts enables the separation portion and the approach
portion to form, but a fifth upper side weft or a plurality of
upper side wefts may be arranged between the fourth upper side weft
and a first upper side weft subsequent thereto. For example, a weft
having a similar design to that of the fourth upper side weft or
having a different design therefrom may be placed, as a fifth upper
side weft, adjacent to the fourth upper side weft and these five
upper side wefts are repeatedly arranged in the order of the first,
second, third, fourth, fifth, first, second, third, fourth, and
fifth upper side wefts.
[0054] Although no particular limitation is imposed on the lower
side design, it is recommended to form lower side wefts having a
long crimp structure as a countermeasure against wear. For example,
a lower side weft may have a design in which it passes over two
warps and passes under six warps to form a long crimp structure or
a ribbed weave design in which two warps form a plain weave, while
being laid in parallel.
[0055] Yarns to be used for the fabric of the invention may be
selected depending on the fabric's purpose. Examples of them
include, in addition to monofilaments, multifilaments, spun yarns,
finished yarns subjected to crimping or bulking such as so-called
textured yarn, bulky yarn and stretch yarn, and yarns obtained by
intertwining them. As the cross-section of the yarn, not only
circular form but also square or short form such as stellar form,
or elliptical or hollow form can be used. The material of the yarn
can be selected freely and usable examples of it include polyester,
polyamide, polyphenylene sulfide, polyvinylidene fluoride,
polypropylene, aramid, polyether ether ketone, polyethylene
naphthalate, polytetrafluoroethylene, cotton, wool and metal. Of
course, copolymer yarns, mixtures, or yarns obtained by
incorporating various substances therein, depending on the material
quality of them may also be used.
[0056] Various materials can be used for a papermaking wire. As
upper side warps, lower side warps, warp binding yarns, and upper
side wefts, it is usually preferred to use polyester monofilaments
having rigidity and excellent size stability. As lower side wefts
required to have wear resistance, those obtained by alternately
arranging polyester monofilaments and polyamide filaments are
preferred, because interweaving them is effective for improving
wear resistance while maintaining rigidity. As the weft binding
yarn, use of polyamide is effective for prevent internal wear.
[0057] With regard to the diameter of constituent yarns, upper side
wefts have preferably a smaller diameter than lower side wefts from
the standpoint of surface smoothness and fiber supporting property.
The diameter of warps can be selected as needed. All the warps may
have an equal diameter or the diameter of lower side warps may be
made greater than that of the other warps. The diameter may be
selected as needed.
[0058] Although the fabric of the invention has, in the cross
direction, separation portions at which two adjacent wefts separate
from each other and approach portions where they approach to each
other alternately, employment of a structure having dehydration
spaces in an oblique direction makes it possible to achieve a
uniform dehydration property, a fiber supporting property, and
surface smoothness throughout the fabric without clogging mesh
openings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0059] FIG. 1 is a schematic view illustrating a separation portion
obtained by weaving first, second, third, and fourth upper side
wefts and warps 5, 6, and 7;
[0060] FIG. 2 is a design diagram illustrating the complete design
or the repeating unit of Embodiment 1 according to the
invention;
[0061] FIG. 3 is a photograph showing the upper side surface of
FIG. 2;
[0062] FIG. 4 is a cross-sectional view taken along a warp of the
fabric according to the invention;
[0063] FIGS. 5A-5R are a design diagrams illustrating an example of
the approach portion of the fabric according to the invention;
and
[0064] FIGS. 6A-6J are design diagrams illustrating a separation
portion of the fabric according to the invention.
DESCRIPTION OF REFERENCE NUMERALS AND SIGNS
[0065] 1u, 2u . . . upper side warp [0066] 2d, 4d . . . lower side
warp [0067] 1B, 3B . . . warp binding yarn [0068] 1'u, 2'u . . .
upper side weft [0069] 1'd, 3'd . . . lower side weft
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0070] Embodiments of the invention will hereinafter be described
referring to accompanying drawings.
[0071] FIG. 1 is, as described above, a plan view illustrating the
separation portion formed by weaving wefts 1, 2, 3, and 4, which
are first, second, third, and fourth upper side wefts, with warps
5, 6, and 7. FIG. 2 is a view obtained by vertically connecting two
design diagrams of the example of the invention. FIG. 3 is a
photograph showing the upper side of the fabric obtained by weaving
based on the design diagram of FIG. 2. FIG. 4 is a cross-sectional
view of warps 1 to 8 illustrated in the design diagram of FIG. 2.
FIGS. 5A-5R are design diagrams showing examples of the approach
portion of the fabric of the invention; and FIGS. 6A-6J are design
diagrams showing examples of the separation portion in the fabric
of the invention.
[0072] The term "design diagram" as used herein means a minimum
repeating unit of a weave pattern (which may also be called
"complete design"). The whole weave pattern is formed by connecting
this complete design longitudinally and latitudinally. In the
design diagram, warps are indicated by Arabic numerals, for example
1, 2 and 3. Warp binding yarns for weaving upper and lower wefts
are indicated by Arabic numerals with "B", upper side warps are
indicated by Arabic numerals with "u", and lower side warps are
indicated by Arabic numerals with "d". In the design diagram, warps
with the same number form a pair. In FIG. 2, an upper side warp "u"
and a warp binding yarn "B" or "b" constitute a warp binding yarn
pair and an upper side warp "u" and a lower side warp "d"
constitute an upper/lower warp pair.
[0073] Wefts are indicated by Arabic numerals with a prime, for
example, 1', 2' and 3'. Upper side wefts and lower side wefts are
arranged vertically but upper side wefts sometimes do not have
lower side wefts thereunder, which depends on an arrangement ratio.
Upper side wefts are indicated by Arabic numerals with "u" and
lower side wefts are indicated by Arabic numerals with "d", for
example 1'u, 2'd.
[0074] In these design diagrams, a mark "x" indicates that an upper
side warp (u) lies over an upper side weft to form a knuckle; a
mark ".quadrature." indicates that a lower side warp (d) lies under
a lower side weft to form a knuckle. A mark ".diamond-solid."
indicates that a warp binding yarn (B) lies over an upper side weft
to form a knuckle; and a mark ".diamond." indicates that the warp
binding yarn (B) lies under a lower side weft to form a knuckle. A
mark ".tangle-solidup." indicates that the warp binding yarn (b)
lies over an upper side weft to form a knuckle.
[0075] In the design diagrams, yarns are vertically overlapped
precisely. They are however illustrated as such for convenience of
drawing and misalignment sometimes occurs in the actual fabric.
[0076] In FIGS. 3 and 4, the separation portion and the approach
portion are marked to facilitate easy understanding, and I, II,
III, and IV represent the separation portion, floating portion,
approach portion, and crimp portion, respectively.
Embodiment 1
[0077] FIG. 2 is a design diagram of a fabric according to
Embodiment 1 of the invention. It is a 16-shaft fabric in which
warp binding yarn pairs (2, 4, 6, and 8) composed of upper side
warps (u) and warp binding yarns (B) and warp pairs (1, 3, 5, and
7) composed of upper side warps (u) and lower side warps (d) are
arranged alternately. An arrangement ratio of upper side wefts and
lower side wefts is 2:1.
[0078] FIG. 2 is obtained by vertically connecting two design
diagrams to each other and in the upper portion thereof, actual
behaviors of wefts constituting the separation portion and the
approach portion are indicated by a dotted line. The first, second,
third, and fourth upper side wefts are illustrated in the
photograph of FIG. 3 showing the upper surface and the separation
portion I, floating portion II, approach portion III, and crimp
portion IV are indicated by dotted lines, respectively.
[0079] In this embodiment, the contiguously arranged warps
constituting the separation portion are, in the case of wefts 2'u
and 3'u illustrated in the design diagram of FIG. 2, an upper side
warp 1u, an upper side warp 2u, and a warp binding yarn 2B which
are composed of a warp pair 1 and a warp binding yarn pair 2 and
the first, second, third, and fourth upper side wefts are indicated
by 1'u, 2'u, 3'u, and 4'u and 5'u, 6'u, 7'u, and 8'u,
respectively.
[0080] With regard to the weft 2'u and 3'u, the three contiguously
arranged yarns, that is, the upper side warp 1u, the upper side
warp 2u, and the warp binding yarn 2B, in the separation portion (I
of FIG. 3), form knuckles corresponding to one weft on the second
upper side weft 2u', the third upper side weft 3'u, and the second
upper side weft 2'u in the order of mention, respectively. The
first upper side weft 1'u and the fourth upper side weft 4'u which
are placed on both sides of the second upper side weft 2'u and the
third upper side weft 3'u so as to sandwich them pass over a
plurality of warps to form a crimp portion (IV of FIG. 3) without
being woven with warps constituting the separation portion.
[0081] In the separation portion, the second and third upper side
wefts 2'u and 3' widen their distance so that a space for widening
on both sides is necessary. The first upper side weft and the
fourth upper side weft have therefore a design in which they form a
crimp passing over a plurality of warps to facilitate movement to
form a space in regions adjacent to the separation portion. In the
crimp portion without weaving positions, wefts move easily. It does
not prevent the second and third upper side wefts from widening
their space.
[0082] On both sides of the separation portion, the second upper
side weft and the third upper side weft form a floating portion
passing over the warps 2 and 4, while being laid in parallel (II of
FIG. 3). Similar to the crimp portion, the floating portion has no
weaving position and facilitates movement therein, which enables
easy movement from the widened position of the separation portion
to the gathered position of the approach portion.
[0083] The approach portion (III of FIG. 3) is formed between these
two floating portions. With regard to the upper side wefts 2u and
3'u, an upper side warp 5u passes over the upper side wefts 2'u and
3'u successively and an upper side warp 6u adjacent thereto passes
over only the upper side weft 3'u.
[0084] The upper side warp 5u passes over both the upper side wefts
2'u and 3'u so that they gather into one. In a portion where the
upper side warp 6u passes over the upper side weft 3'u, only the
upper side weft 3'u is withdrawn further into the layer and is
positioned lower than the knuckle of the upper side warp 5u.
[0085] It cannot be denied that a portion where yarns approach to
each other such as the approach portion is inferior in dehydration
property and breathability to a portion where yarns have a large
mesh opening as in the separation portion. A difference in height
among knuckles constituting the approach portion as in the
invention does not inhibit the dehydration property because an
oblique water channel is formed.
[0086] In the lower side, a lower side weft has a design in which
it passes over one warp, under four warps, over one warp, and then
under two warps. In the present embodiment, on the lower surface
side, warp binding yarns function and form a design similarly to
lower side warps.
* * * * *