Note: Descriptions are shown in the official language in which they were submitted.
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METHOD OF MANUFACTURING LINE OF AUTOHESION THREAD
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a method of manufacturing
a line of autohesion thread in which adjacent filaments are
substantially fused together.
Background Art
Fishing lines for leisure and fishery, materials for
fisheries such as a longline of tuna fishery, and threads to
be employed for rope, gut or kite string are roughly divided
mainly into monofilament yarn and braided yarn such that plural
monofilaments are braided.
Monofilament yarn has low frictional resistance in rubbing
against other matters by reason of having a smoother surface
than braided yarn . For example , in the case of using monofilament
yarn as a fishing line, frictional resistance caused by the
rubbing of a fishing line and a guide in throwing in a fishing
line is so low that a bait can be thrown exactly to a long distance.
Monofilament yarn is also superior in drainability by reason
of holding no water inside. In addition, braided yarn is cut
with difficulty, and when the yarn is cut, the yarn in a cut
portion is split and the cut portion becomes feathery, so that
the handling is difficult; however, monofilament yarn also has
an advantage in that it has no such problem. However, for example,
in the case where resin composing the yarn is ultra high
molecular weight polyethylene or fully aromatic polyamide, it
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is necessary to use a solvent in spinning and remove the solvent
after spinning, which is a problem that it is difficult to
manufacture a monofilament having a certain thickness or more,
which is appropriate for uses such as a fishing line, rope or
gut as described above.
On the other hand, braided yarn can be made into a line
of thread having thickness appropriate for uses as described
above irrespective of the kind of resin as a raw material by
reason of employing plural monofilaments or a multifilament.
In addition, braided yarn has such an advantage that it is possible
to combine plural kinds of filaments, and as a result, an effect
such as adjustment of desired specific gravity, which is not
obtained in a single filament, can be attained. In monofilament
yarn, it is naturally impossible to combine plural kinds of
filaments.
JP-A-9-98698 reports a method of manufacturing a fishing
line in such a manner that plural filaments of polyolef in are
braided or twisted, and thereafter exposed to a temperature in
the melting range of polyolefin while drawn at a draw ratio of
1.0 or more to thereby fuse adjacent filaments. The inventors
of the present invention, however, have found out that it is
practically difficult to substantially fuse adjacent filaments
in the above-mentioned fishing line by such a method, and
accordingly that the application of physical force by use to
the fishing line thus manufactured disjoints the bond of fiber
by reason of not being actually substantially fused to be
incapable of achieving the original object of making a pseudo
monofilament by fusing, that is, the problem is that the
application of physical force by use causes the fishing line
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to have no differences with ordinary braided yarn. Further,
the inventors of the present invention have found out a defect
such that heat treatment in such a method decreases the strength
of the fishing line, which thus cannot but be drawn in order
to compensate for the decreased strength, and consequently the
drawing compensates for the strength, while the fishing line
becomes greatly thinner to the extent of the thickness of
approximately 60% or less compared to the thickness of the fishing
line before the treatment, thereby to deteriorate wear
resistance.
The inventors of the present invention have earnestly
studied a yarn having both of the above-mentioned advantage of
monofilament yarn and the advantage of braided yarn to develop
a line of thread in which plural filament yarn of high strength
fiber are integrated by using low-temperature thermal adhesion
resin having a lower melting point than the melting point of
the above-mentioned filament yarn (JP-A-2002-54041) . As a
result of extensive studies, they have also developed a line
of thread in which low-temperature thermal adhesion resin is
replaced with a hot melt adhesive (JP-A-2003-116431) .
SUMMARY OF THE INVENTION
The present invention is intended to provide a method of
manufacturing a line of fusion thread having both of the
advantages of monofilament yarn and of braided yarn, such that
a smooth surface is offered, the cutting thereof is easy,
filaments composed of the line of thread are not frayed in
cutting, and additionally drainability and durability such that
the application of physical force by use does not disjoint the
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bond of fiber are superior, and then plural kinds of filaments
can be combined.
Through intensive studies for achieving the above-mentioned
object, the inventors of the present invention have obtained
unexpected finding such that plural filaments comprising a
thermoplastic resin are paralleled, twisted and/or braided if
desired, and subsequently drawn under heating at a draw ratio
of less than 1.0, thereby substantially fusing the adjacent
filaments completely without a fusing medium. The inventors
of the present invention have found that the drawing under heating
at a draw ratio of less than 1.0 allows a line of fusion thread
obtained by hot drawing treatment to become thicker as compared
with the line before the treatment, whereby the above-mentioned
problem in publicly known art is solved. Substantially complete
fusing of adjacent filaments in this manner allows a new line
of thread having the following advantages, which does not belong
to monofilament yarn nor braided yarn. That is to say, a line
of fusion thread of the present invention has a smooth surface
and is also superior in drainability by reason of holding no
water inside. In addition, the above-mentioned line of thread
is easily cut and component filaments are not frayed not merely
in cutting but also in long-term use. Thus, resin composed of
a filament is not limited to a single kind while having the
advantage of monofilament yarn, and a combination of filaments
of two different kinds or more may perform characteristics of
each of the filaments. The most preferable resin to be used,
however, is a high strength filament such as an ultra high
molecular weight polyethylene filament.
The inventors of the present invention have completed the
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present invention through further studies.
That is to say, the present invention relates to:
(1) a method of manufacturing a line of fusion thread
characterized in that plural filaments comprising a
5 thermoplastic resin are paralleled, twisted and/or braided
and subsequently drawn under heating at a draw ratio
of less than 1.0 to substantially fuse the adjacent filaments
and thereafter drawn under heating at a draw ratio of more than
1 . 0 ,
(2) the method of manufacturing a line of fusion thread
according to the above (1) , wherein the thermoplastic resin is
a polyamide resin, a polyester resin, a fluororesin or a
polyolef in resin,
(3) the method of manufacturing a line of fusion thread
according to the above (1) , characterized in that the filaments
comprising a thermoplastic resin are filaments having a tensile
strength of 20 g/d or more,
(4) the method of manufacturing a line of fusion thread
according to any one of the above (1) to (3) , wherein the
temperature for the drawing under heating at a draw ratio of
less than 1.0 is higher than the melting point of the filaments
comprising a thermoplastic resin,
(5) the method of manufacturing a line of fusion thread
according to any one of the above (1) to (4) , wherein the outer
periphery of the thread is further coated with a synthetic resin
after the heat drawing at a draw ratio of more than 1.0,
(6) a method of manufacturing a line of fusion thread
characterized in that plural filaments comprising a
thermoplastic resin are paralleled so as to surround a core string
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and further twisted, or plural filaments comprising a
thermoplastic resin are braided around a core string, and
subsequently drawn under heating at a draw ratio of less
than 1.0 to thereby substantially fuse the adjacent filaments,
(7) the method of manufacturing a line of fusion
thread according to the above (6), wherein thereafter drawn
under heating at a draw ratio of more than 1.0,
(8) a method of substantially fusing adjacent
filaments characterized in that the plural filaments comprising
a thermoplastic resin are paralleled, twisted and/or braided,
and subsequently drawn under heating at a draw ratio of less
than 1.0,
(9) a line of fusion thread characterized by being
manufactured by a method according to any one of the above (1)
to (8),
(10) a line of fusion thread characterized by
containing plural filaments comprising a thermoplastic resin
and not containing a fusing medium, wherein the adjacent
filaments are substantially fused together, and
(11) the line of fusion thread according to the
above (10), containing plural filaments comprising a
thermoplastic resin wherein the adjacent filaments are
substantially fused, characterized in that the thickness of
said line of thread is within a 10% range of that of a line of
thread containing filaments of the same thermoplastic resin
wherein the number of the filaments is the same as said line
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6a
of thread and the adjacent filaments are not fused; and that
the tensile strength of said line of thread is more than that
of the line of unfused thread.
As clarified from the above, in a line of thread of
the present invention, filaments composing the line of thread are
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fused together; however, an adhesive for fusing the filaments
and a fusing medium such as low-melting fusion thread described
in JP-A-2003-116431 are not used. A manufacturing method of
the present invention is characterized by performing hot drawing
at a draw ratio of less than 1.0 and thereafter further hot drawing
at a draw ratio of more than 1Ø
A line of autohesion thread while composed of plural
filaments of the present invention has a smoother surface than
a conventional line of thread comprising braided yarn.
Therefore, frictional resistance in rubbing against other
matters is decreased to improve durability. For example, when
a line of autohesion thread of the present invention is used
as a fishing line, frictional resistance between a fishing line
and a guide is so low that a bait can be thrown exactly to a
long distance. In addition, reeling operation is so easily
performed as to scarcely twine and tangle.
A line of autohesion thread of the present invention scarcely
holds water therein and is superior in drainability for the reason
that adjacent filaments are substantially fused completely.
Thus, particularly, a line of autohesion thread of the present
invention can appropriately be used as fishing lines for leisure
and fishery, and materials for fisheries.
Further, a line of autohesion thread of the present invention
is easily cut and component filaments are not frayed after being
cut, that is, a cut portion does not become feathery, whereby
the handling in tying thread is favorable.
In addition, in a line of autohesion thread of the present
invention, an effect which is not obtained in a single filament,
such as adjustment of optional specific gravity, can be fulfilled
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by using plural kinds of filaments and inserting a core string
into the center of a line of thread. Alternatively, the initial
strength can be maintained even though single yarn denier is
not thinned, so that a line of thread superior in wear resistance
can be manufactured.
DETAILED DESCRIPTION OF PREFERRED EXAMPLES
The present invention relates to a method of manufacturing
a line of autohesion thread characterized in that plural
filaments comprising a thermoplastic resin are paralleled,
twisted and/or braided if desired, and subsequently drawn under
heating at a draw ratio of less than 1.0 to thereby substantially
completely fuse the adjacent filaments to be subsequently drawn
under heating at a draw ratio of more than 1. 0 . More particularly,
the present invention is characterized in that, for example,
(a) plural filaments of thermoplastic resin are paralleled, (b)
plural filaments of thermoplastic resin are paralleled and
further twisted, (c) plural filaments of thermoplastic resin
are paralleled and braided, or (d) plural filaments of
thermoplastic resin are paralleled, twisted and subsequently
braided, and thereafter subjected to drawing under heating at
a draw ratio of less than 1.0 and further drawing under heating
at a draw ratio of more than 1Ø
A filament comprising a thermoplastic resin to be employed
in a manufacturing method of the present invention is hereinafter
described.
Examples of the thermoplastic resin to be employed in a
manufacturing method of the present invention include polyamide
resins, polyester resins, fluororesins and polyolefin resins.
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Specific examples of the polyamide resin are aliphatic
polyamides such as nylon 6, nylon 66, nylon 12 and nylon 6,10,
and a copolymer thereof, or semi-aromatic polyamides formed by
aromatic diamine and dicarboxylic acid, or a copolymer thereof.
Specific examples of the polyester resin are polyesters
or a copolymer thereof polycondensed from aromatic dicarboxylic
acids (e.g. terephthalic acid, isophthalic acid,
naphthalene- 2,6 - dicarboxylic acid, phthalic
acid,
a, p- ( 4 - carboxyphenyl ) ethane , 4,4' -dicarboxyphenyl , 5-sodium
sulfoisophthalic acid, etc . ) , aliphatic dicarboxylic acids (e.g.
adipic acid, sebacic acid, etc. ) , or esters thereof, and diol
compounds (e.g. ethylene glycol, diethylene glycol,
1,4-butanediol, polyethylene glycol, tetramethylene glycol,
etc. ) .
Specific examples of the fluororesin are polyvinylidene
fluoride,
polytetrafluoroethylene,
polymonochlorotrifluoroethylene or polyhexafluoropropylene,
or a copolymer thereof.
Specific examples of the polyolefin resin are polyethylene
or polypropylene.
A filament comprising a thermoplastic resin to be employed
in the present invention is preferably a high-strength filament
having a tensile strength of approximately 20 g/d or more,
preferably approximately 25 to 50 g/d, more preferably
approximately 30 to 40 g/d. Here, "tensile strength" can easily
be measured, for example, in a manner according to JIS L 1013
"Testing methods for man-made filament yarns" by a tensile tester
such as a universal tester AUTOGRAPH AG-100kN1 ( trade name,
manufactured by Shimadzu Corporation) .
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The filament comprising a thermoplastic resin is preferably
a high-strength filament.
Specific examples of the above-mentioned high-strength
filament include an ultra high molecular weight polyethylene
5 filament, a fully aromatic polyamide filament, a heterocyclic
high-performance filament, and a fully aromatic polyester
filament. Among them, an ultra high molecular weight
polyethylene filament comprising a flexible polymer is
preferable.
10 The above-mentioned ultra high molecular weight
polyethylene filament signifies a filament comprising ultra
high molecular weight polyethylene. Here, ultra high
molecular weight polyethylene has a molecular weight of
approximately 200,000 or more, preferably approximately 600,000
or more, and includes a homopolymer of ethylene and also a
copolymer of ethylene and lower a-olefins of about 3 to 10 carbon
atoms such as propylene, butene, pentene and hexene. In the
case of a copolymer of ethylene and a-olefin, preferred is a
copolymer wherein the proportion of the a-olefin is approximately
0 . 1 to 20 on average , preferably approximately 0 .5 to 10 on average
with respect to 1000 carbon atoms in the polyethylene chain.
A method of manufacturing the ultra high molecular
weight polyethylene filament is disclosed, for example, in
JP-A-55-5228 and JP-A-55-107506, and these publicly known
methods may be employed. Commercial products such as DYNEEMA
( registered trademark) ( trade name, manufactured by Toyobo . Co.,
Ltd.) and SPECTRA (trade name, manufactured by Honeywell
International Inc.) may be used as the ultra high molecular
weight polyethylene filament.
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A filament as a raw material for a line of autohes ion thread
of the present invention may take any of forms such as a
multifilament made of plural filaments, a monofilament made of
one filament and a monomultifilament such that a plurality of
the above-mentioned monofilaments are doubled. A line of
autohesion thread of the present invention may be composed of
a form of only one filament or a mixed form of plural filaments
among a multifilament, a monofilament and a monomultifilament .
A filament to be used in the present invention may be a filament
such that a cross section thereof is perfectly circular or flat.
A filament to be used in the present invention may have a hollow
structure.
A filament to be used in the present invention may contain
various publicly known additives within a range of not
deteriorating the object of the invention. Examples of such
additives include a pigment, a coloring matter, a stabilizer,
a plasticizer or a lubricant to be detailed below, which may
be used in a combination of two or more additives. Examples
of the additives also include a magnetic material, a conductive
material and a material having high dielectric constant.
Specific examples of the above-mentioned material include
calcium carbonate , barium carbonate , magnesium carbonate , clay,
talc, mica, feldspar, bentonite , aluminum oxide, magnesium oxide,
titanium dioxide, silica and gypsum. These materials may be
coated with stearic acid, acrylic acid or the like. A multi-,
a mono - or a monomulti-filament to be used in the present invention
may be colored with a solution or dispersion containing a coloring
matter or a pigment.
A filament to be used in the present invention may contain
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metallic particles in order to adjust specific gravity and
sedimentation velocity. Examples of a raw material composing
metallic particles include iron, copper, zinc, tin, nickel or
tungsten, which may be used singly, or in a mixture or an alloy
of two or more of metallic raw materials. Among them, tungsten
particles are preferably used. The reason therefor is that
tungsten is so high in its specific gravity as to easily allow
weight to a line of thread, and therefore addition in a small
quantity thereof offers an effect of increasing specific gravity
while restraining a decrease in strength to the utmost. These
metallic particles can be applied to the present invention
irrespective of the form of powder or granules. The average
particle diameter thereof is appropriately approximately 20 !im
or less, preferably approximately 10 [tm or less. The
above-mentioned range is preferable for the reason that too large
particle diameter of metallic particles deteriorates general
uniformity after mixing. In addition, the added quantity of
metallic particles is preferably approximately 1 to 90 parts
by weight, more preferably approximately 5 to 70 parts by weight
with respect to 100 parts by weight of the resin.
Thermoplastic resin containing a metal is produced by
melt-kneading metallic particles, for example, with the use of
a uniaxial or biaxial kneader, and a filament containing the
above-mentioned metallic particles can be manufactured from the
resin by using a widely performed melt spinning method.
In the present invention, only a filament comprising one
kind of thermoplastic resin may be used, or a combination of
filaments comprising plural kinds of thermoplastic resins may
be used. Preferable examples of an embodiment include a line
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of autohes ion thread made of only a filament comprising one kind
of thermoplastic resin. With regard to the present invention,
in the case of using a combination of filaments comprising plural
kinds of thermoplastic resins, a combination of filaments
comprising thermoplastic resins having the melting range close
to each other is preferably used; more specifically, a
combination of DYNEEMA (registered trademark) and a filament
comprising polyethylene or polypropylene is preferably used.
Each process in the manufacturing method of the present
invention is hereinafter described.
In the present invention, the above-mentioned plural
filaments comprising a thermoplastic resin are paralleled, and
twisted and/or braided if desired.
In paralleling plural filaments, the filaments may be
paralleled so as to center a core string and surround it if desired.
A method of twisting plural filaments is not particularly
limited, and twisting can be performed by using publicly known
twisters such as a ring twister, a double twister or an Italian
twister. The degree of twisting in the present process is not
particularly limited, and twisting is preferably performed so
that twist constant K is approximately 0.2 to 1.5, more preferably
approximately 0.3 to 1.2, further more preferably approximately
0.4 to 0.8. Twist constant K is calculated by the following
equation: K = txD1/2 [in which t denotes number of twist ( time/m)
and D denotes degree of fineness ( tex) ] . Degree of fineness
in the above-mentioned equation is measured in accordance with
JIS L 1013 (1999) .
A method of braiding plural filaments is not particularly
limited, and braiding is ordinarily performed by using a braider
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( a braiding machine ) . For example, four filaments are prepared,
and then a right-hand or left-hand filament are alternately
placed in the middle and braided up. The number of filaments
to be used for braiding is not limited to four, but occasionally
eight, twelve or sixteen. Filaments to be used for braiding
may previously be twisted. In addition, a core string as
described above is centered, around which plural filaments can
be braided.
Subsequently, the obtained paralleled yarn, twisted yarn
or braided yarn is drawn under heating at a draw ratio of less
than approximately 1Ø
A method of drawing treatment can adopt a publicly known
method such as drawing while heating in the air. Drawing may
be performed in one stage or two stages or more. The temperature
in drawing can not unconditionally be determined, since it varies
depending on the kind or diameter of a filament, or draw speed,
for example, it is ordinarily a temperature of the melting point
of a filament - approximately 10 C or more. The upper limit
of temperature in drawing is not particularly limited. More
specifically, in the case where a filament is an ultra high
molecular weight polyethylene filament, the temperature in
drawing is approximately 150 C or more (preferably approximately
150 to 170 C) .
The process of drawing is characterized by being performed
at a draw ratio of less than approximately 1Ø This process
allows plural filaments to be substantially fused together.
Relaxation of a line of thread under heating in this manner allows
adjacent filaments to be substantially fused together without
a fusing medium. Here, "adjacent filaments are substantially
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fused" means that component filaments are not disentangled and
frayed even though a line of autohesion thread manufactured in
the present invention is cut in an optional place and then a
cut portion is rubbed by hand. A fusing medium means a substance
5 for promoting or assisting fusion, for example, including a
thermal adhesion resin, an adhesive, a mineral oil (such as
mineral oil of heat-transfer grade having an average molecular
weight of 250 to 7 0 0 ) , a paraffin oil and a vegetable oil (such
as coconut oil) . Such fusing medium is not necessary, needless
10 to say, for manufacturing a line of autohesion thread to be
manufactured in the present invention, and not necessary, for
manufacturing other products such as a composite and fabric by
using a line of autohesion thread to be manufactured in the present
invention; however, such a medium may be used if desired.
15 Subsequently, the line of thread obtained in the previous
process (drawing under heating at a draw ratio of less than 1 . 0 )
is drawn under heating at a draw ratio of more than approximately
1 . 0 . In the case where a line of thread which is difficult in
drawing, such as metal wire and inorganic fiber, is used for
core string, it is preferable not to perform the present process,
and in the case where a line of autohesion thread to be manufactured
by a method of the present invention is composed of only a filament
comprising a thermoplastic resin, it is preferable to perform
the present process.
A method of drawing treatment can adopt a publicly known
method such as drawing while heating in liquid or gas. Drawing
may be performed in one stage or two stages or more. The drawing
treatment is characterized by being performed at a draw ratio
of more than approximately 1 . 0 . The draw ratio for the drawing
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treatment may be properly selected in accordance with the
conditions such as the kind of filament to be used, whether or
not drawing treatment has been performed for the filament as
a raw material, or at what draw ratio the drawing was performed
in the case where drawing treatment has been already performed.
In the case where a filament, such as a commercial filament,
drawn already at a draw ratio of more than 1.0 is used as a raw
material in the previous process, a draw ratio in the present
process (drawing under heating at a draw ratio of more than 1.0)
is usually approximately 1.01 to 5, preferably approximately
1.01 to 3, more preferably approximately 2.2 to 3. Meanwhile,
in the case of using an undrawn filament in the previous process,
a draw ratio in the present process is usually approximately
1.01 to 15, preferably approximately 2 to 10, more preferably
approximately 4 to 8. Here, "an undrawn filament" means a
filament not drawn at all in manufacturing processes or a filament
drawn at a draw ratio less than a draw ratio of a commercial
filament in manufacturing.
In the present invention, a taper shape can be formed in
drawing in the following manner. Specifically, a taper shape
can be formed in drawing by adjusting the draw speed. More
specifically, a taper shape can be formed by taking an advantage
such that an increase in draw speed decreases diameter in a
longitudinal direction and a decrease in draw speed increases
diameter in a longitudinal direction. In changing draw speed
as described above, it is preferable that change in draw speed
is gently inclined toward increase or decrease. That is, draw
speed is preferably increased or/and decreased gradually in
drawing. If change in draw speed is such gentle change, draw
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speed may be linearly changed or not. Draw speed in drawing
can not unconditionally be determined, since it varies depending
on the kind or diameter of a filament. For example, the ratio
of draw speed in forming a portion of the largest diameter to
draw speed in forming a portion of the smallest diameter is
preferably approximately 1:1 . 5 to 4.
Other preferable examples of an embodiment of a line of
autohesion thread to be manufactured in the present invention
include a line of autohesion thread having a core string
comprising thermoplastic resin, in which plural filaments
comprising a thermoplastic resin are placed so as to center the
core string and the adjacent filaments are substantially
completely fused. More specifically, a line of autohesion
thread is included, in which plural filaments comprising
thermoplastic resin are paralleled so as to surround the core
string or plural filaments comprising thermoplastic resin are
braided around core string, and then the adjacent filaments are
substantially completely fused. In the embodiment , with regard
to a filament comprising a thermoplastic resin, only a filament
comprising one kind of thermoplastic resin may be used, or a
combination of filaments comprising plural kinds of
thermoplastic resins may be used; only a filament comprising
one kind of thermoplastic resin is preferably used.
The manufacture of a line of autohesion thread in the above
manner generally allows the manufactured line of thread to
contain no fusing medium and adjacent filaments to be
substantially fused together. The present invention provides
a line of fusion thread containing plural filaments comprising
a thermoplastic resin wherein the adjacent filaments are
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substantially fused, characterized in that the thickness of said
line of thread is within an approximately 10% range (preferably
5%) of that of a line of thread containing filaments of the
same thermoplastic resin wherein the number of the filaments
is the same as said line of thread and the adjacent filaments
are not fused; and that the tensile strength of said line of
thread is more than that of the line of unfused thread. According
to the present invention, a thickness of the above-mentioned
line of thread is ordinarily denoted as denier.
In a line of autohesion thread of the present invention,
plural filaments composing a line of autohesion thread are
substantially fused together. "To be substantially fused"
means a state such that even though the manufactured line of
thread is cut to hold a cut portion between the pad of a forefinger
and the pad of a thumb in a hand of an adult male and then the
line of thread is attempted to be crumpled while the largest
manual pressure of an adult male is applied thereto, the line
of thread is not frayed through visual observation. "Complete
fusion" in the present invention means that in the case where
the line of thread is cut in an optional place and the
above-mentioned test is repeated 100 times, the line of thread
is not frayed by 100%, and not fraying by 85% or more is regarded
as pass in the present invention, preferably by 90% or more.
Plural filaments of a line of autohesion thread may be filaments
of a single kind or a mixture of filaments of two kinds or more.
In the present invention, a line of autohesion thread to
be obtained in the above manner may further be coated with a
synthetic resin. It is needless to say that such a line of thread
is also included in a line of fusion thread of the present
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invention.
The synthetic resin (hereinafter also referred to as
"coating resin") to be used for the above-mentioned coating in
the present invention may employ publicly known resins, which
can preferably adhere closely to a line of autohesion thread
of the present invention. In particular, a resin which
withstands long-term use outdoors and is superior in durability
such as rubbing and bending fatigue is more preferable as the
above-mentioned coating resin. In the case where the outer
periphery of a line of autohesion thread, which is DYNEEMA, of
the present invention is coated with a coating resin by extrusion
coating to be detailed below, the coating resin preferably has
a melt index of approximately 0.1 g/10 minutes or more, more
preferably approximately 0.1 9/10 minutes to 1000 g/10 minutes.
A coating resin having a melt index in the above-mentioned range
is preferably used in order to coat without deteriorating tensile
strength of a line of autohesion thread of the present invention
as a core. Here, melt index of a resin is measured by a melt
indexer (L-202, manufactured by Takara Kogyo Co., Ltd.) in a
method in accordance with JIS K 7210 (1976) "Determination of
the melt mass-flow rate (MFR) and the melt volume-flow rate (MVR)
of thermoplastics".
Examples of the coating resin include polyolef in resins
such as high-density polyethylene, polypropylene,
ethylene-vinyl acetate copolymer, and a modified product
thereof; polyamide resins such as nylon and copolyamide ; acrylic
resins or a copolymerizedmodified product thereof; polyurethane
resins; polystyrene resins; vinyl acetate resins; polyvinyl
chloride resins; and epoxy resins.
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In the present invention, a resin containing metallic
particles may be used as a coating resin. The inclusion of
metallic particles brings an advantage capable of manufacturing
a line of thread having an optional specific gravity,
5 particularly a line of thread having a high specific gravity
irrespective of specific gravity peculiar to the coating resin.
The kind or content of metallic particles here used is preferably
the same as the case where metallic particles are contained in
a filament.
10 In the present invention, a method of coating the outer
periphery of a line of autohesion thread of the present invention
with a coating resin can adopt a publicly known method such as
pressure extrusion coating. Among them, a method by pipe
extrusion coating is appropriate. A method by pipe extrusion
15 coating is such that a molten coating resin is extruded from
an extruder and adhered closely to a preheated line of thread
as a core under pressurized conditions, whereby adherence of
a film becomes markedly superior. In addition, the coating resin
may be applied by using publicly known means such as an applicator,
20 a knife coater, a reverse-roll coater, a gravure coater, a flow
coater, a rod coater and a brush, or a method that a line of
thread as a core is immersed in a tub storing coating resin in
molten state or solution state and then pulled up, out of which
line an excess quantity is squeezed, may be used.
On the occasion of coating with the above-mentioned coating
resin, the shape of a line of autohesion thread of the present
invention can be formed into a taper shape. A method of forming
a taper shape may employ a publicly known method. For example,
the number of revolutions of a measuring pump (a gear pump) put
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in an extruder is optionally fluctuated to change discharge
quantity of the resin and further control the duration in the
number of revolutions under each situation, so that a taper shape
having respective lengths can be formed in intended thick portion,
thin portion and taper portion. The shape of a taper portion
can be changed by relative length of change-over time in a
measuring pump from high-velocity revolution to low-velocity
revolution or from low-velocity revolution to high-velocity
revolution.
The coating of the above-mentioned line of autohesion thread
with coating resin in this manner makes a line of autohesion
thread further superior in drainability to be manufactured.
The use of a line of autohesion thread to be manufactured
by a method of the present invention is not particularly limited,
for example, which line can appropriately be used for fishing
lines, particularly for various leisure and fishery, materials
for fisheries such as a longline of tuna fishery, rope, gut,
kite string, "weedeater" string, cords for various industrial
materials such as cord for a blind, dial cord, cord for a portable
phone strap, and extension cord, Western-style bowstring,
musical instrument's string, string for safe lock, or suture
for operation.
Example 1
Four pieces of DYNEEMA (registered trademark, manufactured
by Toyobo. Co . , Ltd.) 100 deniers were braided up by a braiding
machine to manufacture braided yarn A. This braided yarn A was
sent into a heating furnace heated to a temperature of 149 C
at a speed of 100 m/minute of a send-in roller and 40 m/minute
CA 02530039 2005-12-14
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of a wind-up roller to manufacture fused yarn B. This fused
yarn B was sent again into a heating furnace heated to a temperature
of 149 C at a speed of 30 m/minute of a send-in roller and 40
m/minute of a wind-up roller to manufacture fused yarn C.
Tenacity (kg) and elongation ( % ) of the manufactured braided
yarn A, fused yarn B and fused yarn C were measured by using
a universal tester AUTOGRAPH AG- 100kN1 ( trade name, manufactured
by Shimadzu Corporation) . The results of measuring were shown
in Table 1.
Table 1
Yarn Quality Denier Tensile Tensile Elongation
Data Tenacity (kg) Strength (g/d) (%)
Braided Yarn A 414 6.21 23.1 6.82
Fused Yarn B 542 5.82 10.7 8.03
Fused Yarn C 400 9.38 23.4 4.75
Example 2
Eight pieces of nylon 6 multifilament yarn 210 deniers
manufactured by Unitika Fibers Ltd. were braided up by a braiding
machine to manufacture braided yarn A'. This braided yarn A'
was sent into a heating furnace heated to a temperature of 220 C
at a speed of 5 m/minute of a send-in roller and 4 m/minute of
a wind-up roller to manufacture fused yarn B. . This fused yarn
B' was sent again into a heating furnace heated to a temperature
of 220 C at a speed of 4 m/minute of a send-in roller and 5.5
m/minute of a wind-up roller to manufacture fused yarn C'.
Tensile tenacity ( kg) , tensile strength ( g/d) and elongation
(%) of the manufactured braided yarn A', fused yarn B' and fused
yarn C' were measured in the same manner as Example 1. The results
of measuring were shown in Table 2.
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Table 2
Yarn Quality Denier Tensile Tensile Elongation
Data Tenacity (kg) Strength (g/d) (%)
Braided Yarn A' 1924 12.49 6.5 34.71
Fused Yarn B' 2386 8.32 3.5 58.10
Fused Yarn C' 1900 13.68 7.2 28.32
A line of thread of the present invention can be utilized
for fishing lines for leisure and fishery, threads for fishery
materials such as a longline of tuna fishery, and threads for
rope, gut or kite string.
