Note: Descriptions are shown in the official language in which they were submitted.
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IN-3398
A MULTILOBAL FIBER WITH V-SHAPED ENDS FOR CARPET YARNS
Field Qf the Invention
The present invention is directed to a multilobal fiber with V-
shaped ends for use as carpet yarns and a spinnerette for the -
manufacture of such fibers.
Backqround _f the Invention -;
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Multilobal, in particular trilobal, fibers and filaments are known -
in the art and have been widely used, especially for carpet yarns.
They show superior properties in bulk and covering power over
fibers having round cross section.
U.S. Pat. No. 3, 194,002 discloses a multifilament yarn having a
non-regular Y-shaped cross section.
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U.S. Pat No. 4,648,830 discloses a spinnerette for producing hollow
trilobal cross-section filaments.
U.S. Pat. No 5,108,838 discloses the trilobal and tetralobal
filaments exhibiting low glitter and high bulk. The filaments
having substantial convex curves.
Disadvantage of the filaments of the prior art is that they can
pack together, requiring more fiber use to achieve adequate cover
in a carpet.
Object of the present invention was to provide a fiber with a
simple cross section, which exhibits good bulk, uneven surface,
high dullness, good soil hiding properties a~d improved color.
EXpress Mail Certificate Tso865976ox ~S dated 11/16/92
2103~
.~nother object was to provide a spinnerette plate with a simple
geometry, which is easy to produce and which allows the manufacture
of fibers described above.
Still another object was to provide a carpet with high dullness,
improved color, good soil hiding properties and improved dye
uniformity.
Summary of the Invention
The object of the present invention could be achieved by a
synthetic fiber, having a multilobal cross section, each lobe of
said multilobal cross section having two ends, one end being
connected to the other lobes, the other end of said lobes radiating
outwardly and being V-shaped ~omprising two-arms. --
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Description of the Fiaures
Fig. 1 is a front view of a trilobal spinnerette capillary of the
prior art. ~ ~ `
Fig. 1 (a) is a cross-sectional view of a fiber spun by a
spinnerette shown in Fiq. 1.
Fig. 2 is a front view of a trilobal spinnerette capillary of the ;present invention comprising a V-shaped end at each lob2.
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Fig. 2 (a) is a cross-sectional view of a fiber spun by a
spinnere~te shown in Pig. 2.
Fig. 3 is a front view of a tetralobal spinnerette ~apillary of the
present invention comprising a V-shaped end at each lobe. ~ ~;
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rig. 3(a) is a cross-sectional view of a fiber spun by a
spinnerette shown in Fig. 3.
Detailed Description of the Invention
The synthetic fibers of the present invention are generally
prepared by melt spinning of a fiber forming polymer through a
spinnerette.
Suitable polymers for the production of the fibers of the present
invention are all fiber forming thermoplastic materials especially -
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polyamides, polyesters, and polyolefins. Suitable polyamides are
nylon 6, nylon 6/6, nylon 6/9, nylon 6/10, nylon 6/12, nylon 11,
nylon 12, copolymers thereof and mixtures thereof.
Preferred polyamides are nylon 6 and nylon 6/6. A suitable
polyester is polyethylene terepthalate.
The polymer is fed into an extruder in form of chips or granules,
melted and directed via DowTHERM9 (Dow Chemical, Midland, Michigan)
heated polymer distribution lines to the spinning head. The
polymer melt is then metered by a highly efficient gear pump to a
spin pack assembly, and extruded through a spinnerette with
capillaries described below.
The spinnerette plate of the present invention has in general at
least one mul~ilobal opening, like tri,- tetra-, penta- or
hexalobal capillary, preferably tri- and tetralobal capillary.
The capillary of the spinnerette plate of the present invention is
described with reference to Fig. 2 for a trilobal opening:
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Lobes (1) (2) and (3) have each two ends, (4), (5~; (4), (6) and
(4) (7). On one end (4) the lobes are connected and radiating
outwardly to the second end of each lobe (5), (6) and (7), which is
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shaped with two arms each (8), (9); (10), (11) and (12) (13).
The angles between the lobes (1), (2) and (3) are from about 100 to
about 140 , preferably about 120C. Fig. 2 is drawn with round arm
ends, but other shapes like rectangular or triangular may also be
used.
The dimensions of the different parts of the capillary of the ;~
present invention are as follows: The length of the lobes (1)
(2) and (3) from one end (4) to the other end (5) (6) and (7) is
from about 0.25 to about 1.0 mm, preferably from about 0.4 to about
0.85 mm. The length of the arms from one end (5), (6) and (7) to
the other end (8), (9); (10), (11) and (12), (13) is from about 0.2
to about 0.8 mm, preferably from about 0.3 to about 0.7 mm. The
diameter of the lobes (1), (2) and (3) and the arms (8), (9); (10),
(11) and (12), (13) are from about 0.04 to about 0.18 mm,
preferably from about 0.08 to about 0.12 mm.
The tetralobal opening in the spinnerette plate aGcording to Fig.
3 has four lobes (27), (28), (29) and (30).
On one end (31) the lobes are connected-to each other and radiating
outwardly, the other end (32), (33), 134) and (35) of each lobe is
V-shaped with two arms (36) and (37), (38) and (39), (40) and (41)
and (42) and (43).
The angles between the lobes (27), (28), (29) and (30) are from
about 80 to 100-, preferably about 90. The angles between the
arms (36) and (37), (38) and (39), (40) and (41) and (42) and (43)
are from about 100 to about 140, preferably about 1~0 .
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The dimensions of the different parts of the capillary are
approximately the same as described for the trilobal opening. The
arm endæ may be round, rectangular or triangular as described for
the trilobal opening.
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The disclosed dimensions are dependent for example on polymer type,
spinning temperature, melt-viscosity of the polymer and quench
medium temperature. ;
The desired "modification ratio" for the resulting filaments is
also an important factor. By the term "modification ratio" (MR), ;~
it is meant the ratio of the radius of a circle which circumscribes `~
the filament cross-section to the radius of the largest circle
which can be inscribed within the filament cross-section.
The two circles are shown as dotted lines in Fig. 2a. The
dimensions in the capillaries of the spinnerette plate are chosen,
that the MR for the cross-section of the resulting fiber is from
about 2 to about 5, preferably from about 3 to about 4.
The respective polymer is extruded through the capillary of the
spinnerette plate described in Fig. 2 or Fig. 3 to form a fiber ~i
having a cross-section described in Fig. 2a or Fig. 3a.
The trilobal cross-section of the fiber according to Fig. 2a has
three lobes (14), (15) and (16) with two ends (17) and (18), ~19)
and (20). On one end (17) the three lobes are connected to each
other and radiating outwardly to the other end of each lobe (18),
(19) and (20), which is V-shaped with two arms (21) and (22), (23)
and (24) and (25) and (26). Each of the V-shaped arms ideally are
shaped, like the filament of Fig. 2a. Fig. 2a is drawn with round
arm ends but other shapes like rectangular or triangular may be
used. -
The tetralobal cross-section of the fiber according to Fig. 3(a)
has four lobe~ (44), (45), (46) and (47) with two ends (48) and
(49), (50) (51) and (52). On one end (48) the lobes are connected
to each other and radiating outwardly to the other end of each lobe
(49), (50), (51) and (52), which is V-shaped with two arms (53) and
(54), (55) and (56) (57) and (58) and (59) and (60).
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The modification ratio (MR) for the trilobal cross-section is from
about 2 to about 5, preferably from about 3 to about 4
The M~ for the tetralobal cross section is from about 2 to about 5,
preferably from about 3 to about 4.
The spinnerette plate o~ the present invention has from about 30 to
about 300 openings in form of the capillaries, described above,
preferably from about 50 to about 200. In case of the manufacture
of staple fibers the spinnerette plate has from 30 to 500-openings,
preferably from about 100 to about 300.
The extruded fibers or filaments are quenched for example with air
in order to solidify the filaments. The filaments are then treated
with a finish comprising a lubricating oil or mixture of oils and
antistatic and antisailing agents. The filaments are then combined
to form a yarn bundle which is then wound onto a suitable package.
In a subsequent step, the yarn is drawn and texturized to form a
bulked continuous filament (BCF) yarn suitable fsr tufting into
carpets. A more preferred technique involves combining the
extruded or as-spun filaments into a yarn, then drawing,
texturizing and winding a package, all in a single step. This one~
step method of making BCF is referred to in the trade as spin-draw-
texturing. The manufacture of staple fibers is also included in
the scope of the present invention.
Nylon filaments for the purpose of carpet manufacturing have
deniers (denier = weight in grams of 9000 meters of yarn) in the
range of about 3 to 75 denier/filament (dpf). A more preferred
range for carpet fibers is from about 15 to 25 dpf.
From here, the BCF yarns can go through various pro¢essing steps
well known to those skilled in the art. The fibers of this
invention are particularly useful in the manufacture of carpets for
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floor covering applications.
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To produce carpets for floor covering applications, the BCF yarns
are generally tufted into a pliable primary backing. Primary
backing materials are generally selected from the group comprising
conventional woven jute, woven polypropylene, cellulosic nonwovens,
and nonwovens of nylon, polyester, and polypropylene. The primary
backing is then coated with a suitable latex material such as a
conventional styrene-butadiene latex, vinylidene chloride polymer,
or vinyl chloride-vinylidene chloride copolymers. It is common
practice to use fillers such as calcium carbonate to reduce latex
costs. The final step is to apply a secondary backing, generally
a woven jute or woven synthetic such as polypropylene.
Fibers with a ~ross section according to the invention have
greater cover or lower bulk density, because they cannot be packed
more tightly together than the trilobal fibers of the prior art.
The less-packing geometry of the new cross sections also offer more
void space, thus more shadows and decreased luster of the carpet
fibers. Light entering the fixed voids defined by the geometric
shape has more difficulty reflecting to the observer without
striking one of the filament arms which are rigidly held in ~
position in the cross section. ~;
By varying the denier per filament, very large modification ratios ;are achievable without varyinq the filament arm cross sectional
thickness which crack, or fibrillate, if they are made too thin. ;~ ;~
Added cover in the tufted carpet can thus be achieved by increasing
the modification ratio beyond the range possible with cross
sections of the prior art plus taking advantage of the lower
potential for the filaments to pack together as previously
described.
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Example 1
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~Nylon 6 (relative viscosity R.V. = 2.68) bulked continuous ~ilament
yarns were produced using conditions shown in Table 1 and a ~ ~ h~
spinnerette having a cross section shown in Fig. 2 with the
following dimensions~
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Length of the lobes (1), (2) and (3): 0.5 mm
Length of the arms (~), (9), (10), (11), (12) and (13): 0.~1 mm
Diameter o~ the lobes and arms: 0.12 mm
Angle between the lobes: 120
The molten polymer was extruded, solidified in a quench zone and
the undrawn yarn wound onto a package. The undrawn yarn was then
drawbulked. The yarn was drawn between two rolls (second roll~
heated). A heated draw pin was used between the two rolls. After
drawing, the yarns were bulked (textured ) with a steam jet and
~ound on a package.
A control yarn (2.9 MR symmetric trilobal) was processed in a
Similar manner. Tufted, heatset carpets (Superba) made f~om yarn
having the section of the present invention exhibited higher bulk, -~-
less luster and improved uniformity when compared to the control
yarn (Table 2).
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Table 1
Example 1 Control
Polymer RV (96%2.68 2.68
Sulfuric acid)
Spinning Temp.,C270 270
Blowbox Air Volume, 240 160
CFM
Spinning Speed, 500 500
meters/min.
Polymer Output, 156 156
gJmin.
Finish on yarn, % -1.5 -1.5
Drawbulking Speed, 1500 1500
m/min.
Draw Ratio 3.1:1 3.1
Hot Pin Temp., C90 90
Steam Jet Temp., C 210 210
Steam Jet Press., 75 75
psig
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Table 2
Example 1 Control
Denier (filaments) 1146 (6.8)1135 (68)
Tenacity, gms/den. 2.45 2.38 ~ ~.
~ Elongation 49.6 55.2 :
% Wet Bulk 11.9 11.7 :.
~ Boiling Water 3.4 3-9
Shrinkage
Modification Ratio 3.37 2.9
Cylinder Bulk 4.87 4.69
cc./gm. :
Carpet Evaluation
Example 1 Control
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Luster (1 = 6 5
brightest 10 =
dullest)
Bulk (1 = least 10 7.0 6.5
= most)
Uniformity (1 = 7.0 5~5
least 10 = best)
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