Note: Descriptions are shown in the official language in which they were submitted.
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DESCRIPTION
FLAT MULTIFILAMENT YARN WOVEN FABRIC
TECHNICAL FIELD
The present invention relates to a flat
multifilament yarn woven fabric. More particularly, the
present invention relates to a woven fabric comprising
multifilament yarns constituted from a plurality of
artificial individual filaments having a flat cross-
sectional profile with two or more constrictions per side
section, and exhibiting a soft hand, a practically high
water absorption, abrasion resistance and vision through-
prevention.
BACKGROUND ART
Currently, various types of poorly air-permeable
woven fabrics are provided for sport cloths and uniform
cloths. As the low air-permeability woven fabrics, high
density woven fabrics formed from synthetic fibers, for
example, polyester or polyamide fibers, and coated woven
fabric in which a resin coating layer is formed on a
woven fabric, and calendered woven fabrics, are known.
However, the high density woven fabrics, surface-
coated and calendered woven fabrics usually have a low
softness (a hard hand), and the surfaces of the fabrics
exhibit a low resistance to abrasion (abrasion
resistance, and thus these types of woven fabrics must be
improved.
Synthetic fibers, for example, polyester and
polyamide fibers have excellent physical and chemical
properties and thus are practically used in various uses
such as clothing and industrial uses. Particularly, the
polyester fibers exhibit excellent mechanical strength,
dimensional stability and an easy-care property, and thus
various types of woven fabric formed from synthetic
fibers, for example, polyester fibers, are used widely.
However, the woven fabrics formed from synthetic
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fibers such as polyester fibers have, in addition to the
above-mentioned advantageous properties, a high
transparency. Thus, when the high transparency synthetic
fibers are formed into a fabric and the fabric is used as
an upper garment a problem such that a garment worn under
the upper garment, namely an undergarment, can be seen
occurs.
As a means for solving the above-mentioned problem,
it is known that inorganic fine particles, for example,
titanium dioxide particles are distributed into the
synthetic fibers. This means can cause the resultant
synthetic fibers to exhibit an increased opacity and thus
an enhanced see through-preventing property. However,
the woven fabric formed from the opaque synthetic fibers
still must have an increased weave density to prevent the
transmission of light through gaps formed between the
yarns from which the woven fabric is formed. This
increase in the weave density causes a problem that the
resultant woven fabric exhibits a decreased softness.
In the case of woven fabric for interior material,
for example, curtains, both the vision through-preventing
property (namely a property of preventing vision through
of an articles and movement of people in the room, and
light transmission must be high. However, usually, those
properties are incompatible with each other and thus are
extremely difficult to realize together.
For this reasons, usually, a thin lace curtain is
arranged on the window side and a thick drape curtain is
arranged on the room side, and in nighttime the drape
curtain is closed, and in daytime the lace curtain is
closed to satisfy both the requirements of vision
through-prevention and of lighting. However, generally
speaking, the thick drape curtain has an excellent vision
through-prevention and a poor light-transmitting
property, and the thin lace curtain has an insufficient
vision through-preventing property not only in nighttime
but also in daytime. Accordingly, it is necessary to
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solve this problem. To solve the problem, for example, a
light-blocking curtain formed from a combined weave
comprising polyester fiber yarns comprising a delustering
agent, for example, titanium dioxide and black colored
polyester fiber yarns containing a black-coloring pigment
and capable of reflecting and absorbing the light, is
disclosed in, for example, Japanese Patent No. 3167586; a
mirror curtain formed from a woven or knitted fabric on
both or one surface of which fabric sheen gloss yarns are
arranged, and having a high prevention property of vision
through from outside to inside of a room through the
curtain, due to scattered light generated when light is
irradiated to the sheen gloss surface of the fabric, and
satisfactory ligh-transmitting property and air-
permeability, is disclosed in, for example, Japanese
Unexamined Patent Publication No. 2000-237,036; and a
light-blocking fabric in which a black-colored light-
shielding layer is formed on a surface of a fabric is
disclosed in, for example, Japanese Unexamined Patent
Publication No. 62-133,787.
The above-mentioned light-blocking fabric having a
black-colored light-blocking layer formed on a fabric
surface and light-blocking curtain have a problem that as
the light-transmitting property is poor, the inside of
the curtained room is dark and an oppressive atmosphere
is created in the curtained room. Also, the light-
transmitting property of the mirror curtain is high.
However, the mirror curtain has a problem that the vision
through-preventing property of the mirror curtain,
~30 particularly in might time, is insufficient, and the
sheeting gloss yarns cause a garish gloss, on the mirror
curtain, to be created.
As mentioned above, a woven fabric having both a
sufficient light-transmitting property and an excellent
vision through-preventing property and usable in
practice, has not yet been provided.
Further, the woven fabric made from synthetic fibers
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is disadvantageous in that the water-absorbing
properties, especially perspiration-absorbing property of
the synthetic fiber woven fabric is poorer than that of
the woven fabric made from natural fibers, for example,
cotton fibers.
As a means for enhancing the water-absorbing
property and perspiration-absorbing property of the
synthetic fiber woven fabric, a water absorption-
enhancing method in which a hydrophilicizing agent is
applied to the woven fabric is known. Also, in the use
of, for example, lining clothes, sport clothes and
uniform clothes, further enhanced water and perspiration-
absorbing properties are required.
Under the above-mentioned circumstances, there is a
strong demand of an artificial fiber woven fabric,
particularly a synthetic fiber woven fabric, having a
soft hand, a high vision through-preventing property and
an excellent water and perspiration absorbing property.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a
flat multifilament yarn woven fabric exhibiting a hand
with a high softness, a high water and perspiration-
absorbing property, abrasion resistance, appropriate air
permeability, light transmission and a high see through-
preventing property.
Another object of the present invention is to
provide a flat multifilament yarn woven fabric useful for
constituting textile materials having an appropriate air
permeability, textile materials having a high vision
through-preventing property, textile materials having a
high water and perspiration-absorbing property and/or
textile materials having a high abrasion resistance.
The above-mentioned objects can be attained by the
flat multifilament yarn woven fabric of the present
invention.
The flat multifilament yarn woven fabric of the
present invention comprises a plurality of multifilament
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yarns comprising a plurality of artificial individual
filaments comprising, as a principal component, an
artificial fiber-forming polymer and having a flat cross-
sectional profile,
5 wherein in both the side sections of a
longitudinal center line of the flat cross sectional
profile of each artificial individual filament, at least
three projections per side section are projecting outward
from the longitudinal center line and at least two
constrictions per side section formed between the
projections are formed approximately in symmetry with
respect to the longitudinal center line, and a degree of
flatness of the cross-sectional profile represented by a
ratio (B/Cl) of a largest length (B) of the cross-
sectional profile in the direction of the longitudinal
center line to a largest width (Cl) of the cross-
sectional profile in the direction at right angles to the
longitudinal center line is 2 to 6, and the woven fabric
has a cover factor of 800 to 3500.
In the flat multifilament yarn woven fabric of the
present invention, the artificial fiber-forming polymer
is preferably selected from polyesters, polyamides,
polyvinylidene chloride, polypropylene, regenerated
cellulose and cellulose acetates.
In the flat multifilament yarn woven fabric of the
present invention, in the cross-sectional profile of the
artificial individual filaments, a ratio (C1/C2) of the
largest width (Cl) to a smallest width (C2) is preferably
in the range of from 1.05 to 4.00.
In the flat multifilament yarn woven fabric of the
present invention, the total thickness of the
multifilament yarns is preferably in the range of from 30
to 170 dtex and the thickness of the individual filaments
is preferably in the range of from 0.5 to 5 dtex.
The flat multifilament yarn woven fabric of the
present invention preferably has a weave structure
selected from plain weave, twill weave and satin weave
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structures.
In the flat multifilament yarn woven fabric of the
present invention, the multifilament yarns comprising the
artificial individual filaments having the flat cross-
sectional profile is preferably contained in an amount of
to 100% by mass based on the mass of the woven fabric.
In an embodiment (1) of the flat multifilament yarn
woven fabric of the present invention, the cover factor
of the woven fabric is in the range of from 1500 to 3500.
10 In the embodiment (1) of the flat multifilament yarn
woven fabric of the present invention, the multifilament
yarn preferably has a number of twists of 0 to
2500 turns/m.
In the embodiment (1) of the present invention, the
flat multifilament yarn woven fabric preferably has an
air permeability of 5 ml/cm2=sec or less, determined in
accordance with JIS L 1096-1998, 6.27.1, Method A (using a
Frazir type tester).
In the embodiment (1) of the flat multifilament yarn
woven fabric of the present invention, the air-
permeability is preferably in the range of from 0.1 to
4 . 0 ml /cm2 = sec.
In the embodiment (1) of the present invention, the
flat multifilament yarn woven fabric preferably has a
water absorption velocity of 40 mm or more, determined in
accordance with JIS L 1096-1998, 6.26.1, (2) Method B
(Byreck method).
In the embodiment (1) of the present invention, the
flat multifilament yarn woven fabric preferably has an
abrasion resistance of 50 abrasions, determined in
accordance with JIS L 1096-1998, 6.171., (1) Method A-1
(flat surface method).
A low air permeability textile material of the
present invention comprises a flat multifilament yarn
woven fabric of the embodiment (1) of the present
invention.
In an embodiment (2) of the flat multifilament yarn
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woven fabric of the present invention, the artificial
individual filaments of the multifilament yarn contains
0.2% by mass or more of a delustering agent, and the
cover factor of the woven fabric is in the range of from
1300 to 3000.
In the embodiment (2) of the flat multifilament yarn
woven fabric of the present invention, the multifilament
yarn preferably has a number of twists of 0 to
1500 turns/m.
In the embodiment (2) of the present invention, the
flat multifilament yarn woven fabric preferably has a
degree of vision through-prevention of the woven fabric
represented, in a L*a*b* color system, by a difference
0 L(= L*,-L*b) between an L* value of the woven fabric
placed on a white plate, represented by L*,, and an L*
value of the woven fabric placed on a black plate,
represented by L*b, is 15 or less.
In the embodiment (2) of the present invention, the
flat multifilament yarn woven fabric preferably has a
water absorption velocity of 40 mm or more, determined in
accordance with JIS L 1096-1998, 6.26.1, (2) Method B
(Byreck method).
A vision through-preventing, perspiration-absorbent
textile material of the present invention comprises a
flat multifilament yarn woven fabric of the
embodiment (2) of the present invention.
In an embodiment (3) of the flat multifilament yarn
woven fabric of the present invention, the artificial
individual filaments of the multifilament yarn contains 0
to 0.2% by mass of a delustering agent and the cover factor
of the woven fabric is in the range of from 800 to 2000.
In the embodiment (3) of the flat multifilament yarn
woven fabric of the present invention, the multifilament
yarn preferably has a number of twists of 0 to
1000 turns/m.
In the embodiment (3) of the present invention, the
flat multifilament yarn woven fabric preferably has a
degree of light transmittance of 10 to 70%, determined in
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accordance with JIS L 1055-1987, 6.1. Method A, at a
degree of illumination of 100000 lx.
A vision through-preventive textile material of the
present invention comprises a flat multifilament yarn
woven fabric of the embodiment (3) of the present
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
Fig. 1 is an explanatory cross-sectional profile of
an example of flat multifilaments usable for the flat
multifilament yarn woven fabric of the present invention,
Fig. 2 is an explanatory cross-sectional profile of
another example of flat multifilaments usable for the
flat multifilament yarn woven fabric of the present
invention, and
Fig. 3 is an explanatory cross-sectional profile of
still another example of flat multifilaments usable for
the flat multifilament yarn woven fabric of the present
invention.
BEST MODE OF CARRYING OUT THE INVENTION
The inventors of the present invention have found
that, in a woven fabric comprising, as warp and/or weft
yarns, multifilament yarns each comprising a plurality of
individual filaments comprising an artificial fiber-
forming polymeric material and having a flat cross-
sectional profile, in the case where the cross-sectional
profile of each of the individual filaments has
projections projecting outward from a longitudinal center
line of the flat profile in the number of 3 or more,
preferably 4 or more, still more preferably 4 to 6, per
one side section of the flat profile with respect to the
longitudinal center line of the flat profile, and
constrictions formed between the projections, in the
number of 2 or more, preferably 3 or more, still more
preferably 3 to 5, per one side section of the flat
profile with respect to the longitudinal center line of
the flat profile, the projections and constrictions being
respectively formed approximately in symmetry with
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respect to the longitudinal center line of the flat
profile, and a flatness of the cross-sectional profile of
the individual filament represented by a ratio (B/Cl) of
the largest length, in the longitudinal direction, of the
flat profile to a largest width (Cl); in the cross
direction at right angles to the longitudinal direction,
of the flat profile is controlled within the range of
from 2 to 6, (1) the flat individual filaments in the
flat multifilament yarns of the resultant woven fabric
are closely contacted at flat peripheries thereof with
each other, and at warp-weft yarn-intersecting portions
of the woven fabric, the closely contacting flat
individual filaments are easily slip-spread by the
compressing pressure of the intersecting warp and weft
yarns to each other, to form, in the woven fabric, broad,
dense intersecting portions in which the gaps between the
flat individual filaments become decreased, and (2) the
flat peripheries of the flat individual filaments closely
contacting each other have a plurality of projections and
a plurality of constrictions and thus are roughened, and
therefore, the frictional resistance between the flat
individual filaments become decreased so that the warp-
weft yarn-intersecting portions of the resultant flat
multifilament yarn woven fabric exhibit a high softness
(flexibility) and a low air permeability.
Further, the inventors of the present invention have
found that the plurality constrictions formed on the
peripheries of the flat individual filament causes a
capillarity to liquids to be generated and thus the woven
fabric of the present invention to exhibit excellent
water and perspiration-absorption property.
Furthermore, the inventors of the present invention
have found that the plurality of productions and
constrictions formed in the peripheries of the flat
individual filaments cause the frictional resistance of
the peripheries of the flat individual filaments and thus
the resultant woven fabric of the present invention to
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exhibit an excellent abrasion resistance. Still
furthermore, the inventor of the present invention have
found that the plurality of projections and constrictions
formed in the peripheries of the flat individual
filaments in the woven fabric of the present invention
cause the peripheries to be roughened surfaces which
scatter light transmitting through the surface by
irregular reflections and reflections of the light and
thus contribute to decreasing the vision through property
of the woven fabric and to preventing seeing an article
through the woven fabric, without significantly decrease
the quantity of light transmitted through the woven
fabric (amount of light lighted through the woven
fabric).
Moreover, the inventors of the present invention
have found that by appropriately establishing the cover
factor of the flat multifilament yarn woven fabric of the
present invention in the range of from 800 to 3500, the
air permeability, water and perspiration-absorbing
property, abrasion resistance and vision through-
preventing property of the flat multifilament yarn woven
fabric of the present invention can be appropriately
controlled and, thereby, various types of textile
materials having the above-mentioned properties can be
provided.
The present invention is one completed on the basis
of the above-mentioned findings.
The flat multifilament yarn woven fabric of the
present invention comprises, as warp and/or weft yarns, a
plurality of multifilament yarns each comprising a
plurality of artificial individual filaments comprising,
as a principal component, a fiber-forming artificial
polymer and having a flat cross-sectional profile.
In the above-mentioned flat multi-filament yarn
woven fabric, for example, referring to Fig. 1, the
profile of a cross-section 1 of an individual filament is
in a flat form in which the width in the direction at
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right angles to the longitudinal center line of the
profile is relatively small in comparison with the
longitudinal length of the profile.
In the cross sectional profile 1 shown in Fig. 1, in
both side sections of the profile with respect to the
longitudinal center line 2, 3 or more projections 3 (4
projections in Fig. 1) projecting outward from the
longitudinal center line and two or more constrictions 4
(3 constrictions in Fig. 1) formed between the
projections are respectively formed per one side section
of the profile, approximately in symmetry with respect to
the longitudinal center line 2. In the cross-sectional
profile of Fig. 1, a flatness of the cross-sectional
profile represented by a ratio (B/Cl) of a largest length
(B) of the profile in the direction of the longitudinal
center line to a largest width (Cl) of the profile in a
direction at right angles to the longitudinal center line
direction is in the range of from 2 to 6.
In the cross-sectional profile of each flat
individual filament, the 3 or more projections and 2 or
more constrictions formed in one side section of the flat
profile are approximately in symmetry, in shape and
location with respect to the longitudinal center line of
the flat profile, with the 3 or more projections and 2 or
more constrictions formed in the opposite side section of
the flat profile, to the above-mentioned one side
section.
In the above-mentioned cross-sectional profile of
the flat individual filaments of the multifilament yarn,
the number of the projections is 3 or more, preferably 4
or more, still more preferably 4 to 6 per one side of the
flat profile. Also, the number of constrictions is 2 or
more, preferably 3 or more, still more preferably 3 to 5,
per one side of the flat profile. Also, the flatness of
the cross-sectional profile is 2 to 6, preferably 3 to 5.
If the number of the projections is 2 or less, and
the number of the constrictions is 1 or less, the
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peripheries of the resultant individual filaments exhibit
an increased frictional resistance, and thus the slip-
spreading of the individual filaments in the warp-weft
intersecting portions of the woven fabric in which
portions a compressive presence of the warp and weft
yarns is applied to each other, becomes insufficient, the
air permeability of the resultant woven fabric becomes to
be difficult to control, and the abrasion resistance of
the resultant woven fabric becomes insufficient, and the
decrease in the number of the constrictions causes the
water and perspiration-absorbing property of the
resultant woven fabric to be insufficient, and the light-
scattering effect on the individual filament peripheries
to be insufficient and thus the resultant wove fabric
exhibits an unsatisfactory vision through-preventing
property.
In the flat multifilament yarn woven fabric of the
present invention, the cross-sectional flatness (B/Cl) of
the individual filaments of the flat multifilament yarn
is 2 to 6, preferably 3 to 5. If the cross-sectional
flatness is less than 2, the bending resistance
(rigidity) of the individual filaments is too high, the
resultant woven fabric exhibits an insufficient softness,
and thus the target soft hand of the woven fabric cannot
be obtained.
Also, when the cross-sectional flatness is less than
2, in the warp-weft intersecting portions of the woven
fabric, the slip-spreading of the individual filaments in
the multifilament yarn due to the compressive pressure of
the warp and weft yarns to each other becomes
insufficient, the gaps between the warp and weft yarns
cannot be sufficiently small, the size of the spaces
between the filaments cannot be sufficiently small, and
thus the air permeability of the resultant woven fabric
becomes difficult to control to a desired level.
Also, individual filaments having a cross-sectional
flatness (B/Cl) of more than 6 are difficult to produce.
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In the cross-sectional profile of the flat
individual filaments of the flat multifilament yarn
usable for the woven fabric of the present invention, the
ratio (C1/C2) of the largest width (Cl) to the smallest
width (C2) in the direction at right angles to the
longitudinal center line of the flat profile is
preferably in the range of from 1.05 to 4.00, more
preferably 1.10 to 2.50. The ratio (C1/C2) as mentioned
above is a parameter relating to a depth of the
constrictions of the flat individual filaments. If the
ratio (C1/C2) is less than 1.05, namely, the depth of the
constriction is too small, the peripheral surfaces of the
resultant flat individual filaments may exhibit too high
a frictional resistance and the resultant woven fabric
may exhibit too high an air permeability and insufficient
abrasion resistance, vision through-preventing property,
and water and perspiration-absorbing properties. Also,
if the ratio (C1/C2) is more than 4.0, the depth of the
constrictions of the flat individual filaments is too
large, the effects of the constrictions is saturated, and
the resultant woven fabric may be disadvantageous in that
the filament-forming procedures may be unstable, the
resultant individual filaments may be slit along the
constrictions, and the uniformity in the cross-sectional
profile of the individual filaments may be degraded.
In each of Figs. 2 and 3, another embodiment of the
cross-sectional profile of the flat individual filaments
usable for the flat multifilament yarn woven fabric of
the present invention is shown.
3n The cross-sections of filament I shown in Fig. 2 has
a profile having similar projections and constrictions
formed in both side sections with respect to the
longitudinal center line 2, to those is Fig. 1, except
that the profile of the projections in Fig. 2 is in the
form of an arc of an ellipse extending along the major
axis of the ellipse and thus the form of the ellipse arc
is more gentle than that of the circle arc form of the
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projections of Fig. 1, and thus the depth of the
constrictions in Fig. 2 is smaller than that in Fig. 2.
The cross-sectional profile of a filament 1 shown in
Fig. 3 has projections and constrictions formed in both
side sections of the flat profile with respect to the
longitudinal center line and in the numbers of 4 and 3
per one side section of the flat profile, respectively.
In Fig. 3, a projection 3a is smaller in width and height
than the other 3 projections 3, and thus the depth of the
constrictions 4a formed in both sides of the
projection 3a namely from the top of the projection 3a to
the bottoms of constrictions 4a is smaller than that of
the other constrictions 4.
The cover factor of the flat multifilament yarn
woven fabric is in the range of from 800 to 3500, as
mentioned above, can be appropriately established in
response to the properties and performances necessary to
the woven fabric.
The cover factor (CF) of a woven fabric is defined
by the following equation.
CF = (DWp/ 1 . 1 ) 1/2 x NWp + (DWf / 1. 1) 1/2 x MWf
In the above-mentioned equation,
DWp represents a total thickness (dtex) of the warp
yarns,
MWp represents a weave density (yarns/2.54 cm) of
the warp yarns,
DWf represents a total thickness (dtex) of the weft
yarns!
MWp represents a weave density (yarns/2.54 cm) of
the weft yarns.
In the flat multifilament yarn woven fabric of the
present invention, if the cover factor (CF) of the fabric
is less than 800, the gaps between the warp and weft
yarns is large and the air permeability of the woven
fabric is difficult to control to a desired value and
also a woven fabric having a vision through-preventing
property at a desired high level is difficult to produce.
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Also, if the cover factor (CF) is more than 3500,
the resultant woven fabric exhibits an insufficient
softness and an unsatisfactory light transmission
(lighting property).
The fiber-forming artificial polymer usable for
forming the flat multifilament yarns for the flat
multifilament yarn woven fabric of the present invention
may be selected from fiber-forming synthetic polymers,
for example, polyester, polyamide polyvinylidene chloride
and polypropylene resins; fiber-forming semisynthetic
polymers, for example, cellulose acetates and regenerated
polymers, for example, regenerated celluloses, etc. In
consideration of the ease or the difficulty in the
production of the flat multifilament yarns, fiber-forming
thermoplastic polymers capable of being formed into
fibers by a melt-spinning method, for example,
polyesters, for example, polyethylene terephthalate,
trimethylene terephthalate, etc.; polyamides, for
example, nylon 6, nylon 66, etc., polyvinylidene chloride
and polypropylene, are preferably used.
In the fiber-forming artificial polymer, an additive
comprising at least one member selected from, for
example, delustering agents (for example, titanium
dioxide, etc.), fine pore-forming agents (for example,
organic sulfonate metal salts, etc.), cationic dye-
dyeability-imparting agent (for example, a sulfonium
isophthalate salt, etc.), antioxidants (for example,
hindered phenol compounds, etc.), thermostabilizers,
flame-retardants (for example, diantimoney trioxide,
etc.), fluorescent brightening agents, coloring
materials, antistatic agents, (for example, organic
sulfonate metal salt, etc.), moisture-conditioning agents
(for example, polyoxyalkyleneglycols, etc.), and anti-
bacterial agents fine particles, etc.), may be mixed.
There is no limitation to the total thickness of the
multifilament yarn and to the thickness of the flat
individual filaments usable for the woven fabric of the
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present invention, as long as the target woven fabric of
the present invention can be obtained. Usually, the
total thickness of the yarn is preferably 30 to 170 dtex,
more preferably 50 to 100 dtex and the thickness of the
individual filaments is preferably 0.5 to 5 dtex, more
preferably 1 to 4 dtex.
Also, there is no limitation to the number of twists
of the flat multifilament yarn usable for the flat
multifilament yarn woven fabric of the present invention,
as long as the target woven fabric of the present
invention can be obtained.
Namely, the number of twists may be appropriately
established in response to the use and the necessary
properties of the target woven fabric. Usually, the
number of twist is preferably 0 to 2500 turns/m, more
preferably 0 to 600 turns/m.
The multifilament yarns usable for the woven fabric
of the present invention may be textured yarns by false-
twisting method, TASLAN method or air texturing method,
for example, an air-interlacing method, as long as the
target woven fabric of the present invention can be
obtained.
In the woven fabric of the present invention, the
warp and/or weft yarns from which the woven fabric is
constituted must be constituted from the multifilament
yarns comprising a plurality of individual filaments
having the flat cross-sectional profile as mentioned
above.
Namely, the flat multifilament yarns may be used as
both the warp and weft yarns, or as either one of the
warp and weft yarns, and the other either one of the warp
and weft yarns may be constituted by yarns different from
the flat multifilament yarns.
The different yarns may be selected from
monofilament yarns, multifilament yarns and spun yarns.
These different yarns may have a specific property, for
example, an anti-static property, a sheening property
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etc. Also, in the warp and/or weft yarns usable for the
woven fabric of the present invention, a small amount of
filaments or fibers different from the flat individual
filaments may be used together with the flat
multifilament yarns, as long as the target woven fabric
of the present invention can be obtained.
In the flat multifilament yarn woven fabric of the
present invention, the content of the flat multifilament
yarns is preferably 10 to 100% by mass, more preferably
20 to 100% by mass, still more preferably 40 to 100% by
mass, based on the total mass of the woven fabric.
The flat multifilament yarns for the woven fabric of
the present invention can be produced by using a
spinneret for flat filaments, for example, a spinneret
provided with a plurality of spinning orifices having a
cross-sectional profile as shown in Fig. 2-C appearing on
page 5 of Japanese Unexamined Patent Publication
No. 56-107,044.
The flat multifilament yarn woven fabric of the
present invention can be produced a conventional weaving
procedure in which the flat multifilament yarns produced
as mentioned above are used as warp and/or weft yarns,
and can be dyed and finished by a conventional dyeing and
finishing procedures. In the case where the flat
multifilament yarns are flat polyester multifilament
yarns, the resultant woven fabric may be subjected to a
mass-reduction treatment with an alkali. Also, in the
finishing procedures, the woven fabric may be subjected
to one or more of water absorption-enhancing treatments
(by coating or impregnating with a water-absorbing agent,
for example, an anionic hydrophilic polymeric compound),
water-repellent treatments (by coating or impregnating
with a water-repellent agent, for example, a water-
repellent fluorine compound), ultraviolet ray-blocking
treatments (by applying a dispersion of ultrafine
particles of a metal oxide), antistatic treatments,
deodorant-applying treatments, mothproofing agent-
CA 02461551 2004-03-23
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applying treatments and a light storage agent-applying
treatments, successively or simultaneously.
In an embodiment of the flat multifilament yarn
woven fabric of the present invention, the thickness of
the warp and weft yarns and the weave density of the warp
and weft yarns are controlled to an extent that the
resultant woven fabric exhibits a cover factor (CF) in
the range of from 1500 to 3500.
In the embodiment (1) of the present invention, the
cover factor of the woven fabric is preferably 1500 to
3000 and preferably 1500 to 2500.
Also, in the embodiment (1) of the present
invention, the flat multifilament yarn preferably has a
number of twists of 0 to 2500 turns/m, more preferably 0
to 600 turns/m, still more preferably 0 turn/m, namely
non-twisted.
In the embodiment (1) of the present invention, the
flat multifilament yarn woven fabric preferably has an
air permeability of 5 ml/cm2=sec or less, more preferably
4 ml/cm2=sec or less, still more preferably 0,1 to
3 ml/cm2=sec. The air permeability is determined in
accordance with JIS L 1096-1998, 6.27.1, Method A (using a
Frazir type tester).
In the embodiment (1) of the present invention, the
flat multifilament yarn woven fabric preferably has a
water absorption velocity of 40 mm or more, more
preferably 50 to 70 mm, determined in accordance with
JIS L 1096-1998, 6.26.1 (2) Method (B) (Byreck method) and
an abrasion resistance of 50 abrasions or more, more
preferably 80 abrasions or more, still more preferably
100 abrasions or more.
On the embodiment (1) of the present invention, if
the cover factor (CF) of the woven fabric is less than
1500, the areas of gaps formed between the warp yearns
and the weft yarns may be too large, the resultant woven
fabric may exhibit too high an air permeability (of, for
example, more than 5 ml/cm2=sec) and insufficient water
CA 02461551 2004-03-23
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and perspiration-absorbing property and an insufficient
abrasion resistance. Also, if the cover factor (CF) of
the woven fabric is more than 3500, the warp and weft
yarns in the resultant woven fabric may closely contact
with each other, the resultant woven fabric may have an
insufficient softness and too high a flexing resistance
and thus the hand of the woven fabric may become
unsatisfactory and the abrasion resistance of the woven
fabric may be insufficient.
In the flat multifilament yarn woven fabric of the
embodiment (1) of the present invention having a cover
factor of 1500 to 3500, the flat multifilament yarns from
which the warp and/or weft yarns of the woven fabric are
constituted, are flattened and laterally spread due to
the compressive pressure generated at the warp-weft
intersecting portions of the fabric, under which
compressive pressure, the flat individual filaments
contacting each other, at the flat periphery thereof,
slip laterally on each other to make the yarn flat. In
this flattening of the yarn, the areas of the gaps
between the warp and weft yarns decrease and thus-the
resultant woven fabric exhibits a decreased air
permeability. Therefore, the flat multifilament yarn
woven fabric of the embodiment (1) of the present
invention preferably exhibits a low air permeability of
5 ml/cm2=sec or less.
In the embodiment (1) of the present invention the
flattening of the flat multifilament yarn causes the
resultant woven fabric to exhibit a decreased flexing
resistance an increased softness and a good soft hand.
Also, in the woven fabric of the embodiment (1) of the
present invention, each of the flat individual filaments
in the multifilament yarns has 3 or more projections
extending along the longitudinal direction of the
periphery and 2 or more constrictions formed between the
projections, per one side section of the flat profile,
and thus the periphery of the flat individual filament is
CA 02461551 2004-03-23
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roughened. Thus, when the individual filaments in the
yarns are brought into contact with each other,
particularly under a compressive pressure generated at
the intersecting portions of the warp and weft yarns, the
contact area of the individual filaments brought into
contact with each other is relatively small, and thus the
frictional resistance between the individual filaments is
small. Therefore, the roughened peripheries of the
individual filaments contributes to enhancing the
softness of the resultant woven fabric. Further, in the
periphery of each individual filament, the constrictions
extending along the longitudinal direction of the
periphery are not, or are substantially not, closed even
when the peripheries of the individual filaments are
brought into contact with each other. Therefore, water
or perspiration can easily diffuse along the
constrictions due to the capillary phenomenon, and thus
the resultant woven fabric exhibits excellent water and
perspiration-absorbing property.
The flat multifilament yarn woven fabric of the
embodiment (1) of the present invention exhibits an
excellent soft hand, a high water and perspiration-
absorbing property and a high abrasion resistance and
thus is useful as low air permeability textile materials
for various clothes, for example, sport clothes and
uniform clothes for men and women, and folk costumes
(native dresses), for example, tabes, undergarments,
lining clothes, hats caps and fabrics for umbrellas and
parasols.
In an embodiment (2) of the flat multi-filament yarn
woven fabric of the present invention, the multifilament
yarns contain a delustering agent in a content of 0.2% by
mass or more, preferably 0.4 to 3.5% by mass, more
preferably 1.0 to 2.5% by mass, and the woven fabric has
a cover factor (CF) of 1300 to 3000, preferably 1400 to
2500.
There is no limitation to the composition and type
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of the delustering agent contained in the multifilament
yarn of the flat multifilament yarn woven fabric of the
embodiment (2) of the present invention, as long as the
target woven fabric of the present invention can be
obtained. Usually, the delustering agent may comprise at
least one type of fine inorganic particles, for example,
titanium dioxide and barium sulfate. If the content of
the delustering agent is less than 0.2% by mass, on the
basis of the total mass of the multifilaments, the
resultant multifilament yarn may exhibit an insufficient
reflectance and thus the resultant woven fabric may be
not able to exhibit a satisfactory vision through-
preventing property. It should be noted that if the
content of the delustering agent exceeds 7% by mass, the
fiber-forming property of the resultant polymer
composition may become unstable.
If the cover factor (CF) of the woven fabric of the
embodiment (2) of the present invention is less than
1300, the gaps between the warp and weft yarns may be too
large, and the resultant woven fabric may exhibit an
unsatisfactory vision through-preventing property. Also,
if the cover factor (CF) if more than 3000, the resultant
woven fabric may exhibit an insufficient softness and an
unsatisfactory hand.
In the case where the woven fabric of the
embodiment (2) of the present invention has a plain weave
structure, the cover factor of the plain weave fabric
preferably in the range of from 1400 to 1800, more
preferably from 1500 to 1700.
In the case where the woven fabric of the
embodiment (2) of the present invention has a twill weave
structure, the resultant twill weave fabric preferably
has a cover factor (CF) of 1900 to 2400, more preferably
2000 to 2300.
There is no specific limitation to the number of
twists of the multifilament yarns usable for the woven
fabric of the embodiment (2) of the present invention, as
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long as the target woven fabric of the present invention
can be obtained. However, in order to fully ensure the
freedom of movement of the individual filaments in the
yarn, relative to each other, the number of twists of the
flat multifilament yarn is preferably 0 to 1500 turns/m,
more preferably 0 to 600 turns/m. Still more preferably,
the number of twists is 0 turn/m, namely, non-twisted.
In the embodiment (2) of the present invention, the
flat multifilament yarn woven fabric preferably has a
degree of vision through-prevention, represented, in a
L*a*b* color system, by a difference A L(= L*,-L*b)
between an L* value of the woven fabric placed on a white
plate, represented by L*,,, and an L* value of the woven
fabric placed on a black plate, represented by L*b, is 15
or less, more preferably 10 to 13. If the degree A L of
the vision through prevention is more than 15, the vision
through preventing property of the resultant woven fabric
may be insufficient, in practice.
The flat multifilament yarn woven fabric of the
embodiment (2) of the present invention, preferably has a
water absorption velocity of 40 mm or more, more
preferably 45 mm or more, still more preferably 50 to
70 mm, determined in accordance with JIS L 1096-1998,
6.26.1, (2) Method B (Byreck method). If the water
absorption velocity is less than 40 mm, the resultant
woven fabric may exhibit insufficient water and
perspiration-absorbing property in practice.
In the flat multifilament yarn woven fabric of the
embodiment (2) of the present invention, the cross-
sectional profile of individual filaments from which the
flat multifilament yarn is constituted is flat. In this
flat cross-sectional profile, three or more projections
and two or more constrictions between the projections per
one side section of the flat profile are formed. Thus
the peripheries of the individual filaments brought into
contact with each other exhibit a low frictional
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resistance to each other and can easily slip on each
other. When a compressive pressure is applied to the
multifilament yarns, the individual filaments can easily
move relative to each other along the contacting
peripheries, so that the multifilament yarn is flattened
and laterally spread. Also, the individual filaments
closely contact at the flat peripheries with each other,
to cause the gaps between the yarns arranged in the woven
fabric to be reduced, and the quantity of light
transmitted through the woven fabric to decrease. Also,
the delustering agent contained in a content of 0.2% by
mass in the individual filaments causes the light
transmittance through the resultant woven fabric to
reduce and the light irradiated toward the woven fabric
to irregularly reflect on the woven fabric. Further, the
plurality of the projections and constrictions formed on
the peripheries of the individual filaments cause the
peripheries of the individual filaments to be roughened
to scatter the incident light and to prevent vision
through the woven fabric. At the intersecting portions
of the warp and weft yarns of the woven fabric, the
flattening and spreading of the multifilament yarns can
cause the intersecting portions to be softened and the
hand of the resultant woven fabric to be soft.
Further, the constrictions extending along the
longitudinal axis of the individual filament can cause a
capillary phenomenon to water and perspiration to be
generated and the resultant woven fabric to exhibit a
high water and perspiration absorption velocity.
Thus, the flat multifilament yarn woven fabric of
the embodiment (2) of the present invention are useful as
a textile material for a use in which high vision
through-preventing property and water and perspiration-
absorbing property are necessary, for example, lining
clothes, sport clothes and uniform clothes.
In an embodiment (3) of the flat multifilament yarn
woven fabric of the present invention, the artificial
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individual filaments of the multifilament yarn contains a
delustering agent in a small content of 0 to 0.2% by mass
and the woven fabric has a cover factor (CF) in the range
of from 800 to 2000.
In the flat multifilament yarn woven fabric of the
embodiment (3) of the present invention, the content of
the delustering agent in the artificial individual
filaments are 0 to 0.2% by mass, preferably 0 to 0.1% by
mass. More preferably, no delustering agent is contained
in the individual filaments. The delustering agent for
the present invention may be selected from conventional
delustering agents, for example, titanium dioxide and
barium sulfate. If the content of the delustering agent
is more than 0.2% by mass, in the preferable use of the
woven fabric of the embodiment (3) of the present
invention, for example, curtains, the resultant woven
fabric may exhibit an insufficient light transmittance
and thus an unsatisfactory lightening property.
In the flat multifilament yarn woven fabric of the
embodiment (3) of the present invention, the
multifilament yarn preferably has a number of twists of 0
to 1000 turns/m, more preferably 0 to 200 turns/m, still
more preferably no twist.
The cover factor (CF) of the flat multifilament yarn
woven fabric of the embodiment (3) of the present
invention is in the range of from 800 to 2000, preferably
from 900 to 1800, more preferably from 1000 to 1800.
If the cover factor (CF) is less than 800, in the
preferable use of the flat multifilament yarn woven
fabric of the embodiment (3) of the present invention,
for example, curtains, the gaps between the warp and weft
yarns in the woven fabric may be too large, and the
resultant woven fabric may exhibit an insufficient vision
through-preventing property. Also, if the cover factor
is more than 2000, the resultant woven fabric may exhibit
an insufficient lighting property.
The flat multifilament yarn woven fabric of the
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embodiment (3) of the present invention, preferably
exhibits a degree of light transmittance of 10 to 70%,
more preferably 20 to 50%, determined in accordance with
JIS L 1055-198õ 6.1. Method A, at a degree of
illumination of 100000 lx. The light transmittance in %
is calculated by subtracting a light-blocking rate in %
of the woven fabric from 100%. If the light
transmittance is less than 10%, in the preferable use of
the woven fabric, for example, curtains, the lighting
property of the resultant woven fabric may be
insufficient. Also, if the light transmittance is more
than 70%, the resultant woven fabric may exhibit an
insufficient vision through-preventing property.
The flat multifilament yarn woven fabric of the
embodiment (3) of the present invention preferably is
non-colored or dyed into a light or moderate color. The
type and amount of the dye used for dyeing may be
established in view of the use and necessary properties
of the resultant dyed woven fabric.
In the flat multifilament yarn woven fabric of the
embodiment (3) of the present invention, the flat
multifilaments are laterally spread and flattened at the
warp-weft-intersecting portions of the woven fabric due
to a compressive pressure generated in the intersecting
portions, the individual filaments are, at flat
peripheries thereof, closely contacted with each other,
to form a dense structure. In this dense structure, the
gaps between the warp and weft yarns are small, and the
quantity of the light passing through the gaps is
reduced. A small amount of the light passing through the
gaps is diffracted in the small gaps and transmitting
light rays through the small gaps adjacent to each other
interfere with each other, to enhance the vision through-
preventing effect of the woven fabric. Also, the
specific cross-sectional profile of the flat individual
filaments in the multifilament yarn causes the irregular
reflection of the incident light on the peripheries of
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the individual filaments and the refraction of the light
transmitted through the filaments are increased in
comparison with filaments having a flat cross-sectional
profile and provided with smooth peripheries, filaments
having a circular cross-sectional profile, and filaments
having a triangular cross-sectional profile. Thus, the
resultant woven fabric exhibits an excellent vision
through-preventing effect without reducing the lighting
property thereof.
The flat multifilament yarn woven fabric of the
embodiment (3) of the present invention exhibits good
soft hand, a low flexing resistance, a low air
permeability and a high abrasion resistance, similar to
those of the embodiments (1) and (2).
For the reasons as mentioned above, the flat
multifilament yarn woven fabric of the embodiment (3) of
the present invention is useful for vision through-
preventing textile materials for interior, for example,
curtains, roll blinds (shades) and partitions.
EXAMPLES
The present invention will be further illustrated by
the following examples which are not intended to limit
the scope of the present invention in any way.
Example 1
A polyethylene terephthalate resin was melt-extruded
at a temperature of 300 C through 30 melt-spinning
orifices formed in a melt-spinneret and having a hole
shape corresponding to the cross-sectional profile of a
filament shown in Fig. 1, which profile has 4 circular
arc-shaped projections and 3 constrictions formed between
the projections, per one side section of the profile,
formed on both the sides of a longitudinal center line of
the profile. The extruded filamentary melt streams were
taken up at a taking up speed of 4000 m/minute, while
cool-solidifying the melt streams. The resultant undrawn
multifilaments were, without winding up, directly drawn
at a temperature of 97 C at a draw ratio of 1.3, to
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prepare a drawn multifilament yarn having a yarn count of
84 dt/30 filaments. The individual filaments of the
multifilament yarn had a cross-sectional profile as shown
in Fig. 1, a flatness of the cross-sectional profile of
3.2, and a filament width ratio C1/C2 was 1.2.
The flat multifilament yarns, which were kept non-
twisted, were used as warp and weft yarns to produce a
plain weave having the following warp and weft densities.
Warp density: 101 warps/2.54 cm
Weft density: 90 wefts/2.54 cm
In the resultant plain weave, a content of the flat
multifilament yarn was 100%. The plain weave was
finished by scouring and dyeing. The finished plain
weave had a cover factor (CF) of 1782.
The finished plain weave was subjected to the
following tests.
(1) Air permeability
The air permeability of the woven fabric was
determined in accordance with JIS L 1096-1998, 6.27.1,
Method A (using a Frazir type tester).
(2) Abrasion resistance
The abrasion resistance of the woven fabric was
determined in accordance with JIS L 1096-1998, 6.17.1, (1)
Method A-1 (flat surface method).
(3) Water-absorbing property
A water-absorption velocity of the woven fabric
was determined in accordance with JIS L 1096-1998, 6.26.1,
(2) Method B (Byreck method).
(4) Hand
The hand of the woven fabric was evaluated, by
touching with a hand, into the following five classes.
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Class Hand
Very high softness, Excellent good
hand
4 High softness, Good hand
3 Sufficient softness, Satisfactory
hand
2 Slightly insufficient softness,
Slightly unsatisfactory hand
1 Insufficient softness,
Unsatisfactory hand
(5) General evaluation.
The general evaluation results of the tested
woven fabric were shown in the following four classes.
Class General evaluation
4 Excellent
3 Good
2 Slightly unsatisfactory
1 Bad
5
The test results are shown in Table 1.
Example 2
A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 1, with exceptions as shown below.
In the cross-sectional profile of the flat
individual filaments, the number of the circular arc-
shaped projections was changed from 4 to 3, and the
number of the constrictions was changed from 3 to 2, per
one side of the longitudinal center line of the flat
profile.
The flatness (B/Cl) of the flat cross-sectional
profile was 3.2, the ratio (C1/C2) was 1.2, and the cover
factor of the plain weave was 1782.
The test results are shown in Table 1.
Comparative
Example 1
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A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 1, with exceptions as shown below.
In the flat cross-sectional profile of the
individual filaments, no constrictions were formed.
The flatness (B/Cl) of the flat cross-sectional
profile was 3.2, the ratio (C1/C2) was 1.0, and the cover
factor of the plain weave was 1782.
The test results are shown in Table 1.
Comparative
Example 2
A plain weave of multifilament yarns was produced
and tested by the same procedures as in Example 1, with
exceptions as shown below.
The flat cross-sectional profile of the individual
filaments was changed to a circular cross-sectional
profile.
The cover factor of the resultant plain weave was
1782.
The test results are shown in Table 1.
Table 1
Item Cross-sectional profile Cover Air Abra- Water- Hand Gene-
Constric- Ratio Ratio factor permea- sion absorp- ral
tion (B/Cl) (C1/C2) (CF) bility resis- tion eva-
number tance veloci- lua-
(per one (Abra- ty tion
side) sion
Example number
No. (ml/cm2 = s) (mm)
Example 1 3 3.2 1.2 1782 0.74 110 55 5 4
2 2 3.2 1.2 1782 0.92 82 50 5 4
Compara- 1 0 3.2 1.0 1782 2.75 56 20 4 2
tive 2 Circular 1782 5.55 45 22 2 1
Example
Example 3
A polyethylene terephthalate resin containing 2.5%
by mass of a delustering agent consisting of titanium
dioxide was melt-extruded at a temperature of 300 C
through 30 melt-spinning orifices formed in a melt-
spinneret and having a hole shape corresponding to the
cross-sectional profile of a filament shown in Fig. 1,
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which profile has 4 circular arc-shaped projections and
3 constrictions formed between the projections, per one
side section of the profile, formed on both the sides of
a longitudinal center line of the profile. The extruded
filamentary melt streams were taken up at a taking up
speed of 4000 m/minute, while cool-solidifying the melt
streams. The resultant undrawn multifilaments were,
without winding up, directly drawn at a temperature of
97 C at a draw ratio of 1.3, to prepare a drawn
multifilament yarn having a yarn count of
84 dt/30 filaments. The individual filaments of the
multifilament yarn had a cross-sectional profile as shown
in Fig. 1, a flatness of the cross-sectional profile of
3.2, and a filament width ratio C1/C2 was 1.2.
The flat multifilament yarns, which were kept non-
twisted, were used as warp and weft yarns to produce a
plain weave having the following warp and weft densities.
Warp density: 101 warps/2.54 cm
Weft density: 84 wefts/2.54 cm
In the resultant plain weave, a content of the flat
multifilament yarn was 100%. The plain weave was
finished by scouring and dyeing. The finished plain
weave had a cover factor (CF) of 1700.
The resultant woven fabric was subjected to the
following tests.
(1) Degree of vision through-prevention
The degree of vision through prevention of the
woven fabric subjected to the test was represented, in a
L*a*b* color system, by a difference A L(= L*,y_-L*b)
J V 1.JC LWCCII all U value of the woven fabric placed an Ci while
plate, represented by L*y,, and an L* value of the woven
fabric placed on a black plate, represented by L*b.
(2) Water-absorbing property
The water absorption velocity of the woven
fabric was determined in accordance with JIS L 1096-1998,
6.26.1, (2) Method B (Byreck method), as in Example 1.
(3) Hand
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The hand of the woven fabric was evaluated, by
touching with a hand, into the following five classes, as
in Example 1.
Class Hand
Very high softness, Excellent good
hand
4 High softness, Good hand
3 Sufficient softness, Satisfactory
hand
2 Slightly insufficient softness,
Slightly unsatisfactory hand
1 Insufficient softness,
Unsatisfactory hand
5 (5) General evaluation.
The general evaluation results of the tested
woven fabric were shown in the following four classes, as
in Example 1.
Class General evaluation
4 Excellent
3 Good
2 Slightly unsatisfactory
1 Bad
The test results are shown in Table 2.
Example 4
A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 3, with exceptions as shown below.
In the cross-sectional profile of the flat
individual filaments, the number of the circular arc-
shaped projections was changed from 4 to 3, and the
number of the constrictions was changed from 3 to 2, per
one side of the longitudinal center line of the flat
profile.
The flatness (B/Cl) of the flat cross-sectional
profile was 3.2, the ratio (C1/C2) was 1.2, and the cover
CA 02461551 2004-03-23
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factor of the plain weave was 1700.
The test results are shown in Table 2.
Comparative
Example 3
A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 3, with exceptions as shown below.
In the flat cross-sectional profile of the
individual filaments, no constrictions were formed.
The flatness (B/Cl) of the flat cross-sectional
profile was 3.2, the ratio (C1/C2) was 1.0, and the cover
factor of the plain weave was 1700.
The test results are shown in Table 2.
Comparative
Example 4
A plain weave of multifilament yarns was produced
and tested by the same procedures as in Example 3, with
exceptions as shown below.
The flat cross-sectional profile of the individual
filaments was changed to a circular cross-sectional
profile.
The cover factor of the resultant plain weave was
1700.
The test results are shown in Table 2.
Table 2
Item cross-sectional profile Cover Degree of Water- Hand Gene-
Constric- Ratio Ratio factor vision absorp- ral
tion (B/Cl) (C1/C2) (CF) through- tion eva-
number prevention veloci- lua-
(per one ty tion
side)
Example
No. (0 L) (mm)
Example 3 3 3.2 1.2 1700 12.5 55 5 4
4 2 3.2 1.2 1700 12.4 50 5 4
Compara- 3 0 3.2 1.0 1700 13.4 20 4 2
tive 4 Circular 1700 15.0 22 2 1
Example
Example 5
A polyethylene terephthalate resin containing no
delustering agent was melt-extruded at a temperature of
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300 C through 30 melt-spinning orifices formed in a melt-
spinnert and having a hole shape corresponding to the
cross-sectional profile of a filament shown in Fig. 1,
which profile has 4 circular arc-shaped projections and
3 constrictions formed between the projections, per one
side section of the profile, formed on both the sides of
a longitudinal center line of the profile. The extruded
filamentary melt streams were taken up at a taking up
speed of 4000 m/minute, while cool-solidifying the melt
streams. The resultant undrawn multifilaments were,
without winding up, directly drawn at a temperature of
97 C at a draw ratio of 1.3, to prepare a drawn
multifilament yarn having a yarn count of
84 dt/30 filaments. The individual filaments of the
multifilament yarn had a cross-sectional profile as shown
in Fig. 1, a flatness of the cross-sectional profile of
3.2, and a filament width ratio Cl/C2 was 1.2.
The flat multifilament yarns, which were kept non-
twisted, were used as warp and weft yarns to produce a
plain weave having the following warp and weft densities.
Warp density: 63 warps/2.54 cm
Weft density: 52 weft/2.54 cm
In the resultant plain weave, a content of the flat
multifilament yarn was 100%. The plain weave was
finished by scouring and dyeing. The finished plain
weave had a cover factor (CF) of 1000.
The resultant woven fabric was subjected to the
following tests.
(1) Light transmittance
The woven fabric was subjected to a measurement
of a light blocking rate in accordance with
JIS L 1055-1987, 6.1, Method A at a degree of illumination
of 100,000 lx, and the light transmittance through the
woven fabric was calculated in accordance with the
following equation.
Light transmittance (%) = 100 - Light blocking rate
(%)
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(2) Vision through-preventing property
Vision through-preventing property in the
daytime
In a room lighted at an illumination of 700 lx
by using a 80W fluorescent lamp for a room, an article
(color: red, form: rectangular parallelepiped,
dimensions: 15 cm x 7 cm x 7 cm) to be seen through a
woven fabric was placed at a location of 20 cm far from a
surface of the woven fabric, and the naked eye of an
observer was positioned outside of the room at a location
of 30 cm away from the opposite surface of the woven
fabric and at an illumination of 100,000 lx of sunlight,
to allow the observer to see the article through the
woven fabric.
The degree of the vision through-prevention of
the woven fabric in the daytime was evaluated in the
following four classes.
Class Degree of vision through prevention
4 Completely not able to recognize the
article
3 Slightly able to recognize the
article
2 Approximately able to recognize the
contours of the article
1 Clearly able to recognize the
article
Vision through-preventing property in the
nighttime
The vision through-presenting property of the
woven fabric in the nighttime was tested by the same
11 -_ 11~ by
method as that for the daytime, except that the observer
for the article was positioned outside the room in the
nighttime at an illumination of 0.2 lx.
The degree of the vision through-prevention of
the woven fabric in the nighttime was evaluated in the
same four classes as those in the daytime.
The test results are shown in Table 3.
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Example 6
A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 5, with excerptions as shown below.
The weave structure of the plain weave was changed
to that having a warp density of 55 warps/2.54 cm and a
weft density of 36 wefts/2.54 cm, and the cover factor
(CF) of the resultant plain weave was 880.
The test results are shown in Table 3.
Example 7
A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 5, with exceptions as shown below.
The weave structure of the plain weave was changed
to that having a warp density of 112 warps/2.54 cm and a
weft density of 74 wefts/2.54 cm, and the cover factor
(CF) of the resultant plain weave was 1800.
The test results are shown in Table 3.
Example 8
A plain weave of flat multifilament yarns was
produced by the same procedures as in Example 5, with
exceptions as shown below.
The flat multifilament yarn was twisted at a number
of twists of 200 turns/m, and the resultant plain weave
exhibited a cover factor (CF) of 1000.
The test results are shown in Table 3.
Comparative
Example 5
A plain weave of flat multifilament yarns was
produced and tested by the same procedures as in
Example 5, with exceptions as shown below.
The flat cross-sectional profile of the individual
filaments of the multifilament yarn had no constrictions.
(Flatness of the flat profile: 3.2, Ratio (C1/C2):
1.0).
The resultant woven fabric had a cover factor (CF)
of 1000.
CA 02461551 2004-03-23
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The test results are shown in Table 3.
Comparative
Example 6
A plain weave of flat multifilament yarns was
produced by the same procedures as in Example 5, with
exceptions as shown below.
The flat cross-sectional profile of the individual
filaments of the multifilament yarn was changed to a
triangular cross-sectional profile.
The resultant woven fabric had a cover factor of
1000.
The test results are shown in Table 3.
Comparative
Example 7
A plain weave of flat multifilament yarns was
produced by the same procedures as in Example 5, with
exceptions as shown below.
The flat cross-sectional profile of the individual
filaments of the multifilament yarn was changed to a
circular cross-sectional profile.
The resultant woven fabric had a cover factor of
1000.
The test results are shown in Table 3.
Comparative
Example 8
A plain weave of flat multifilament yarns was
produced by the same procedures as in Example 6, with
exceptions as shown below.
The flat cross-sectional profile of the individual
filaments of the multifilament yarn was changed a
triangular cross-sectional profile.
The resultant woven fabric had a cover factor of
880.
The test results are shown in Table 3.
Comparative
Example 9
A plain weave of flat multifilament yarns was
CA 02461551 2004-03-23
37 -
produced by the same procedures as in Example 7, with
exceptions as shown below.
The flat cross-sectional profile of the individual
filaments of the multifilament yarn was changed to a
triangular cross-sectional profile.
The resultant woven fabric had a cover factor of
1800.
The test results are shown in Table 3.
Table 3
item Cross-sectional profile Cover Light Vision through-
factor trans- preventing
(CF) mittance property
Number of Ratio Ratio Daytime Nighttime
constric- B/Cl Cl/C2
tions per
one side
Example No. ($)
5 3 3.2 1.2 1000 35 4 3
Example 6 3 3.2 1.2 880 40 3 3
7 3 3.2 1.2 1800 25 4 4
8 3 3.2 1.2 1000 38 3 3
5 0 3.2 1.0 1000 30 2 2
Compa- 6 Triangular cross section 1000 25 2 1
rative 7 Circular cross section 1000 30 2 2
Example 8 Triangular cross section 880 30 2 1
9 Triangular cross section 1800 15 3 2
INDUSTRIAL APPLICABILITY OF THE INVENTION
In the flat multifilament yarn woven fabric of the
present invention, the specific flat cross-sectional
profile of the individual filaments in the multifilament
yarn enables the individual filaments to easily slip on
each other due to a compressive pressure generated at the
intersecting portions of the warp and weft yarns to cause
the multifilament yarn to be flattened and laterally
spread, and the gaps between the yarns to become narrow.
Therefore, the air permeability of the woven fabric can
be appropriately controlled. The resultant woven fabric
of the present invention exhibits a high abrasion
resistance and an excellent water and perspiration
absorbing property, and can scatter the incident light by
diffraction and irregular reflection of the light, to
reduce the vision through property of the woven fabric,
CA 02461551 2004-03-23
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without significantly decreasing the light transmittance
of the woven fabric. Accordingly, the flat multifilament
yarn woven fabric of the present invention is useful as a
low air permeability textile material, a vision through-
preventing textile material, a water and perspiration-
absorbing textile material and lighting, vision through-
preventing textile material.
