U.S. patent application number 10/416616 was filed with the patent office on 2004-01-22 for production method of synthetic and yarn traverse device.
Invention is credited to Hashimoto, Norio, Minagawa, Kazuyuki, Sano, Masuki, Sugahara, Toru, Toda, Hidenobu.
Application Number | 20040012115 10/416616 |
Document ID | / |
Family ID | 30428210 |
Filed Date | 2004-01-22 |
United States Patent
Application |
20040012115 |
Kind Code |
A1 |
Minagawa, Kazuyuki ; et
al. |
January 22, 2004 |
Production method of synthetic and yarn traverse device
Abstract
In the process of drawing/heat treating synthetic fiber thread
melted and spun via a plurality of godet rollers and subsequently
winding the same, accumulation of extraneous matter on the surface
of the godet rollers may be prevented by performing multistage
drawing/heat treatment while reciprocating the thread in the
direction of the axis of rotation of the godet roller using the
godet rollers at least two of which have surfaces having the
roughness of 0.5.ltoreq.Ra.ltoreq.5 and one of which has a surface
at a temperature of at least (melting point of synthetic
fiber-70.degree. C.), whereby occurrence of thread breakage or
generation of fuzz may be prevented and synthetic fiber whereof the
rate of operation can be increased and efficiency of manufacture is
improved may be obtained.
Inventors: |
Minagawa, Kazuyuki;
(Okazaki-shi, JP) ; Hashimoto, Norio;
(Okazaki-shi, JP) ; Sugahara, Toru; (Okazaki-shi,
JP) ; Toda, Hidenobu; (Okazaki-shi, JP) ;
Sano, Masuki; (Anjo-shi, JP) |
Correspondence
Address: |
IP DEPARTMENT OF PIPER RUDNICK LLP
3400 TWO LOGAN SQUARE
18TH AND ARCH STREETS
PHILADELPHIA
PA
19103
US
|
Family ID: |
30428210 |
Appl. No.: |
10/416616 |
Filed: |
May 13, 2003 |
PCT Filed: |
February 20, 2002 |
PCT NO: |
PCT/JP02/01440 |
Current U.S.
Class: |
264/210.7 ;
264/211.12 |
Current CPC
Class: |
D01D 5/16 20130101; D01D
10/02 20130101 |
Class at
Publication: |
264/210.7 ;
264/211.12 |
International
Class: |
D01D 005/16 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 26, 2001 |
JP |
2001-49761 |
Claims
What is claimed is:
1. A method of manufacturing synthetic fiber comprising the steps
of performing multistage drawing/heat treatment on the thread of
synthetic fiber formed by melt spinning using a plurality of godet
rollers, and subsequently winding the obtained thread, wherein at
least two sets of godet rollers out of the plurality of godet
rollers have surface roughness in the range of 0.5-5 .mu.m, wherein
at least one set of godet rollers out of these godet rollers having
surface temperatures not less than (the melting point of the
synthetic fiber-70.degree. C.) is used, and wherein the thread is
reciprocated in the direction of the axis of rotation of the godet
roller.
2. A method of manufacturing synthetic fiber according to claim 1,
wherein the tensile stress of the thread is not less than 1. 4
cN/dtex in the last drawing step of the multistage drawing.
3. A method of manufacturing synthetic fiber according to claim 1
or claim 2, wherein the thread of the synthetic fiber is not less
that 200 dtex.
4. A method of manufacturing synthetic fiber comprising the steps
of performing multistage drawing/heat treatment on the thread of
synthetic fiber formed by melt spinning using a plurality of godet
rollers, and subsequently winding the obtained thread, wherein the
thread is reciprocated in the direction of the axis or rotation of
the godet roller while synchronizing at least one thread converging
guide for allowing the thread to pass through before and/or after
the thread is wound around the godet roller which wind the thread
first after passing the spinning duct and one or plurality of
drawing operation aiding units disposed between the plurality of
godet rollers.
5. A method of manufacturing synthetic fiber according to claim 4,
wherein the drawing process is a multistage drawing process
including at least two stages.
6. A method of manufacturing synthetic fiber according to any one
of claim 1 to Claim5, wherein the thread is multi-thread including
at least two lines of thread.
7. A method of manufacturing synthetic fiber according to any one
of claim 4 to claim 6, wherein the drawing operation aiding unit is
a thread entangling device.
8. A method of manufacturing synthetic fiber according to any one
of claim 1 to claim 7, wherein the width Y(mm)of reciprocating
motion satisfies the following expression (1).
XF.ltoreq.Y.ltoreq.2(XP-XF) (1) where; XF is the width of the
thread (mm), and XP is the thread pitch (mm) between the adjacent
threads.
9. A method of manufacturing synthetic fiber according to any one
of claim 1 to claim 8, wherein the cycle of the reciprocating
motion is at least 5 seconds.
10. A thread traversing device to be used for a method of
manufacturing synthetic fiber in which the thread of synthetic
fiber formed by melt spinning is drawn/heat treated and then wound
by a plurality of godet rollers, comprising at least one thread
converging guide for allowing the thread to pass through before
and/or after the thread is wound around the godet roller located
immediately after the spinning duct, an drawing operation aiding
unit disposed between a plurality of godet rollers, and means for
synchronizing the thread converging guide and the drawing operation
aiding unit.
11. A thread traversing device according to claim 10, wherein the
means for synchronizing the thread converging guide and the drawing
operation aiding unit comprises a driving motor, a shaft mounted on
the driving motor in the direction of the axis of rotation of the
godet roller, and means mounted on the shaft and connected to both
of the thread converging guide and the drawing operation aiding
unit respectively for converting rotary motion into reciprocating
motion, and the thread converging guide and the drawing operation
aiding unit are respectively adapted to be reciprocated in the
direction of the axis of rotation of the godet roller.
12. A thread traversing device according to claim 10, wherein the
means for synchronizing the thread converging guide and the drawing
operation aiding unit comprises at least two driving motors, shaft
respectively mounted on the respective driving motors in the
direction of the axis of rotation of the godet roller, and means
mounted on the respective shafts and connected to both of the
thread converging guide and the drawing operation aiding unit
respectively for converting rotary motion into reciprocating
motion, and the thread converging guide and the drawing operation
aiding unit are respectively adapted to be slid in the direction of
the axis of rotation of the godet roller.
13. A thread traversing device according to claim 12, wherein the
means for synchronizing the thread converging guide and the drawing
operation aiding unit comprises at least two phase detecting means
for detecting that the shaft mounted on each driving motor rotates
to the prescribed position, and adapted to stop the rotation of the
shaft provided with the one of the phase detecting means when the
prescribed position is detected by one of the phase detecting
means, and to rotate the stopped shaft when the prescribed position
is detected by the other one of the phase detecting means.
14. A thread traversing device according to any one of claim 10 to
claim 13, wherein a speed reducer is provided between the shaft and
the driving motor.
15. A thread traversing device according to any one of claim 10 to
claim 14, wherein the cycle of the reciprocating motion of the
thread converging guide and the drawing operation aiding unit is
not less than 5 seconds.
16. A thread traversing device according to any one of claim 10 to
claim 15, wherein the thread converging guide and the drawing
operation aiding unit are adopted to be used for the tread
including a plurality of lines of thread.
17. A thread traversing device according to any one of claim 10 to
claim 16, wherein the drawing operation aiding unit is a thread
entangling device.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] In the manufacture of synthetic fiber, especially, of
industrial fiber formed by drawing/heat treatment of undrawn thread
by the use of a plurality of godet roller groups, the present
invention relates to a method of manufacturing high-strength
synthetic fiber for maintaining drawing/heat treatment of synthetic
fiber stable for a long term by resolving problems such as thread
breakage or generation of fuzz to avoid accumulation of extraneous
matters on the surface of high-temperature godet rollers, for
increasing the rate of operation by reducing the number of times
the machine have to be stopped for removing extraneous matters from
the godet rollers, and for improving productive efficiency by
reducing abrasion of the surface of the godet roller, and a thread
traversing device to be used directly in the same method.
[0003] 2. Description of the Related Art
[0004] In the manufacture of synthetic fiber as typified by
polyamide or polyester, among others, of industrial synthetic
fiber, it is required to achieve high strength by heat drawing
undrawn thread under large magnification and high tensile stress
generally by the use of a plurality of godet roller groups.
Therefore, at least one of a plurality of godet roller groups have
to be set to high temperature in order to heat setting the thread
drawn into a high magnification. This drawing/heat treatment
process of undrawn thread been suffering from such phenomenon that
attachment and accumulation of extraneous matters dropped from the
traveling thread on the surface of the godet rollers with time
causes abnormal states of drawing, which has a serious impact on
the quality/appearance and productive efficiency of fiber
obtained.
[0005] The abnormal states of drawing here include winding of
traveling thread on the godet roller, generation of fuzz due to
breakage of a filament of the thread, and breakage of the thread
itself due to increase in surface frictional force caused by the
external matters attached and accumulated on the surface of the
godet roller.
[0006] There is recognized an unfavorable phenomena that the
extraneous matters attached and accumulated on the godet roller set
at a high temperature near the melting point of polymer block heat
transmission between the godet roller and the thread, which results
in insufficient heat treatment of the thread, and thus variations
in quality/appearance of the obtained drawn thread with time. Since
stain on the surface of the godet roller that is set to a high
temperature may occur in relatively a short time, and may cause the
abnormal states of drawing as described above, the process of
cutting the thread compulsory regularly or every time the abnormal
states are detected, and stopping the operation of the drawing
machine to remove the extraneous matters on the godet roller is
made frequently. Therefore, the problem of lowering of the
productive efficiency and of appearance of the product has been in
the news.
[0007] The conceivable accumulated deposits on the godet roller
include anchored matter generated mainly from spinning oil applied
on the thread being transformed by heat on the drawing/heat
treatment roller, oligomers separated out of the thread and those
heat-transformed matters, and silica contained in water.
[0008] The following related arts are disclosed as methods of
avoiding and removing abnormal drawing due to accumulated deposits
as described above.
[0009] For example, in Japanese Patent Laid-Open No.78364/1997 and
Japanese Patent Laid-Open No.187469/1996, systems for cleaning the
extraneous matters by bringing the scraper blade or the rotating
brush into contact on the surface of the godet roller are proposed
respectively. However, in the manufacture of industrial fiber, a
high-temperature heated roller is used as a godet roller in many
cases, and thus the aforementioned scraper blade or the rotating
brush cannot remove accumulated deposits easily. In addition, since
the thick thread is drawn by a high tensile stress, there is also a
problem in that the devices such as the scraper blade or the
rotating brush mounted in the vicinity of the godet roller are
frequently broken due to the thread wound on the roller after
breakage of the thread.
[0010] In Japanese Patent Laid-Open No.170215/1996, a method and
apparatus for reciprocating (traversing) a traveling thread on the
godet roller by means of a thread guide in the field of
manufacturing fiber for clothes are proposed.
[0011] However, since the denier of threads being larger than fiber
for clothes, threads are normally drawn to a large magnification in
the manufacture of industrial fiber, occurrence of a single
filament breakage or thread breakage is distinctive in comparison
with the manufacture of fiber for clothes. In addition, since the
surface temperature of the godet roller is set to the higher value
than that used in the manufacture of fiber for clothes,
accumulation of extraneous matters on the godet roller caused by
heat-transformed spinning oil is distinctive, and thus the impact
on the appearance of the obtained yarn is clearly visible.
Therefore, generation of transformed spinning oil cannot be
sufficiently prevented simply by reciprocating the thread on the
godet roller by the use of the thread guide, and thus transformed
spinning oil is accumulated on both ends of the reciprocating
motion of the thread guide, which may result in increase in thread
breakage or generation of fuzz with time. In order to a void such
phenomena, the machine has to be stopped many times in order to
remove the extraneous matters on the godet roller, which impairs
increase of the rate of operation.
[0012] In addition, in the manufacture of industrial fiber, drawing
operation aiding units such as an air guide for preventing a single
filament breakage on the roller, a heat treatment cylinder for
fixation of a drawing point, and a heat plate and a heat treatment
cylinder for aiding drawing operation are provided among a
plurality of drawing rollers in many cases, and thus misalignment
between these drawing operation aiding units and the traveling
thread when the traveling thread is reciprocated, which may result
in breakage of the traveling thread due to abrasion with these
drawing operation aiding units.
SUMMARY OF THE INVENTION
[0013] Accordingly, in the manufacture of synthetic fiber,
especially, of industrial fiber formed by drawing/heat treatment of
undrawn thread by the use of a plurality of godet rollers, it is an
object of the present invention to provide a method of
manufacturing synthetic fiber for maintaining drawing/heat
treatment of high-strength synthetic fiber stable for a long term
by resolving problems such as thread breakage or generation of
fuzz, which are distinctive in industrial fiber, to perform
high-temperature large-magnification drawing while avoiding
accumulation of extraneous matters on the surface of a
high-temperature godet roller, for increasing the rate of operation
by reducing the number of times the machine has to be stopped for
removing extraneous matters from the godet roller, and for
improving productive efficiency, and a thread traversing device to
be used directly in the same method.
[0014] In order to achieve the aforementioned object, the invention
provides a method of manufacturing synthetic fiber comprising the
steps of performing multistage drawing/heat treatment on the thread
of synthetic fiber formed by melt spinning using a plurality of
godet rollers, and subsequently winding the obtained thread,
wherein at least two sets of godet rollers of the plurality of
godet rollers have surface roughness Ra in the range of 0.5- 5
.mu.m, wherein at least one set of godet rollers out of these godet
rollers have surface temperatures not less than (the melting point
of the synthetic fiber-70.degree. C.), and wherein the thread is
reciprocated in the direction of the axis of rotation of the godet
roller.
[0015] In a method of manufacturing synthetic fiber according to
the invention, the following points (a) to (e) are preferred modes
of the invention respectively, and by applying these conditions,
more preferable effects can be expected.
[0016] (a) The tensile stress of the thread is not less than 1.4
cN/dtex in the last drawing step of the multistage drawing;
[0017] (b) Total denier of the thread of the synthetic fiber is not
less than 200 dtex;
[0018] (c) The thread is a multi-thread including at least two
lines of thread;
[0019] (d) The cycle of the reciprocating motion of the thread is
at least 5 seconds.
[0020] (e) The width of reciprocating motion of Y(mm) satisfies the
following expression (1).
XF.ltoreq.Y.ltoreq.2(XP-XF) (1)
[0021] where;
[0022] XF is the width of the thread (mm), and XP is the thread
pitch (mm) between the adjacent threads.
[0023] In the manufacture of industrial fiber involving drawing
operation aiding units, in order to solve the problem in that fuzz
tends to be generated by abrasion of the traveling thread with the
drawing operation aiding unit when the thread is moved, the
invention provides a method of manufacturing synthetic fiber
comprising the steps of performing drawing/heat treatment on the
thread of synthetic fiber formed by melt spinning with a plurality
of godet rollers, and subsequently winding the obtained thread,
wherein the thread is reciprocated in the direction of the axis of
rotation of the godet roller while synchronizing a thread
converging guide for allowing the thread to pass through before
and/or after the thread is wound around the godet roller located
immediately after the spinning duct and one or plurality of drawing
operation aiding units disposed between the plurality of godet
rollers. In this method of manufacturing synthetic fiber, the
following points (f) to (j) are preferred modes of the invention
respectively, and by applying these conditions, more preferable
effects can be expected.
[0024] (f) The drawing process is a multistage drawing process
including at least two stages.
[0025] (g) The thread is multi-thread including at least two lines
of thread.
[0026] (h) The drawing operation aiding unit is a thread entangling
device.
[0027] (i) The width of reciprocating motion Y (mm) satisfies the
following expression (1):
XF.ltoreq.Y.ltoreq.2(XP-XF) (1)
[0028] where;
[0029] XF is the width of the thread (mm), XP is a thread pitch
(mm) between the adjacent threads.
[0030] (j) The cycle of the reciprocating motion is at least 5
seconds.
[0031] The thread traversing device according to the invention is a
device to be used for a method of manufacturing synthetic fiber in
which the thread of synthetic fiber formed by melt spinning is
drawn/heat treated and then wound by a plurality of godet rollers,
comprising a thread converging guide for allowing the thread to
pass through before and/or after the thread is wound around the
godet roller located immediately after the spinning duct, an
drawing operation aiding unit disposed between a plurality of godet
rollers, and means for synchronizing the thread converging guide
and the drawing operation aiding unit.
[0032] In the thread traversing device according to the invention,
the following points (k) to (p) are preferred modes respectively,
and by applying these conditions, more preferable effects can be
expected.
[0033] (k) means for synchronizing the thread converging guide and
the drawing operation aiding unit comprises a driving motor, a
shaft mounted on the driving motor in the direction of the axis of
rotation of the godet roller, and means mounted on the shaft and
connected to both of the thread converging guide and the drawing
operation aiding unit respectively for converting rotary motion
into reciprocating motion, and the thread converging guide and the
drawing operation aiding unit are respectively adapted to be slid
in the direction of the axis of rotation of the godet roller with
these means;
[0034] (l) Means for synchronizing the thread converging guide and
the drawing operation aiding unit comprises at least two driving
motor, shafts respectively mounted on the respective driving motors
in the direction of axis of rotation of the godet roller, and means
mounted on the respective shaf ts and connected to the thread
converging guide and the drawing operation aiding unit respectively
for converting rotary motion into reciprocating motion, and the
thread converging guide and the drawing operation aiding unit are
respectively adapted to be slid in the direction of the axis of
rotation of the godet roller with these means;
[0035] (m) Means for moving the thread converging guide and the
drawing operation aiding unit simultaneously in (1) comprises at
least two phase detecting means for detecting that the shaft
mounted on each driving motor rotates to the prescribed position,
and adapted to stop the rotation of the shaft provided with the one
of the phase detecting means when the prescribed position is
detected by one of the phase detecting means, and to rotate the
stopped shaft when the prescribed position is detected by the other
one of the phase detecting means;
[0036] (n) The cycle of the reciprocating motion of the thread
converging guide and the drawing operation aiding unit is not less
than 5 seconds;
[0037] (o) The thread converging guide and the drawing operation
aiding unit are adopted to be used for the tread including at least
two lines of thread; and
[0038] (p) The drawing operation aiding unit is a thread entangling
device.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] FIG. 1 is a schematic front elevation of the
spinning/drawing device provided with a thread traversing device
according to the invention;
[0040] FIG. 2 is a schematic side view of the apparatus shown in
FIG. 1;
[0041] FIG. 3 is a schematic perspective view of the thread
traversing device according to the embodiment of the invention;
[0042] FIG. 4 is a schematic perspective view of the thread
traversing device according to the embodiment of the invention;
and
[0043] FIG. 5 is a block diagram of controlling means for a phase
detecting means.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0044] The method of manufacturing synthetic fiber according to the
invention and the details of the thread traversing device will be
described below.
[0045] The synthetic fiber provided for the manufacturing method
according to the invention includes threads formed of polyamide,
polyester, polyolefin, and alamid, but it is not limited thereto as
far as it is such material that the formed thread can be drawn/heat
treated by the use of godet rollers.
[0046] The surface roughness Ra of at least two sets of godet
rollers out of the godet rollers used in the invention have to be
between 0.5 and 5 .mu.m, more preferably, between 1 and 3
.mu.m.
[0047] A set of godet rollers here means a set of rollers having
the same speed of revolution for winding the thread by more than
one turn for example as the first godet roller (18a and 18b) shown
in FIG. 1.
[0048] The surface roughness Ra is calculated, according to
JISB0601, by providing a Surfcorder SE 1700 manufactured by Kosaka
Lab. and measuring the section curve using a sensing pin with
radius 2 .mu.m at a feeding speed of 0.5 mm/s and a cut-off of 0.8
mm or 2.5 mm to obtain the curve of the surface roughness of the
godet roller.
[0049] When performing multistage drawing, if the surface of the
godet rollers on which drawing is performed has roughness in this
range, drawing is performed not only between rollers, but also
while the thread is wound on the rollers. When Ra is smaller than
0. 5 .mu.m or larger than 5 .mu.m, since the frictional force
generated between the thread and the roller increases, drawing of
the thread on the roller becomes increasingly difficult, and thus
it becomes difficult to prevent generation of a single filament
breakage to obtain a high-strength fiber. The surface roughness Ra
in the range between 1 and 3 .mu.m is more preferable since the
frictional force further decreases. By setting the surface
temperature of at least one set of godet rollers out of two sets of
godet rollers to at least (the melting point of synthetic fiber
thread-70.degree. C.), heat treatment can be performed on the
surface of the roller effectively.
[0050] The melting point of the thread here is obtained from a
trace of variations of heat quantity obtained by melting 2 mg of
sample by the use of DSC-7 type manufactured by Perkin Elmer Inc.,
quenching and solidifying it by liquid nitrogen, and scanning the
sample at the speed of 20.degree. C./min., which is regarded as a
temperature at a maximum endothermic peak.
[0051] The temperature below this value (the melting point of
synthetic fiber thread-70.degree. C.) is not preferable for the
manufacture of industrial fiber, which is the object of the
invention, from such reasons that stable drawing cannot be
performed, and heat dimension stability of the drawn yarn is
lowered due to insufficient heat treatment. When performing heat
treatment under such a high temperature condition, a
heat-transformed matter caused by spinning oil attached on the
thread is accumulated on the surface of the godet roller, which
leads to increase in a single filament breakage or thread breakage,
but according to the invention, accumulation of such transformed
spinning oil may be prevented by reciprocating the thread in the
direction of the axis of rotation of the godet roller. In other
words, according to the invention, transformation and accumulation
of residue of spinning oil may be prevented by organic unity of the
constructions described above, and thus the manufacture of
high-strength industrial fiber may be performed stably. When the
surface roughness Ra of the roller for performing the heat
treatment is smaller than 0.5 .mu.m, the contact area between the
traveling thread and the roller increases. Therefore, even when the
thread is moved in the direction of the axis of rotation of the
godet roller, the transformed matter sticks to the surface of the
roller, and thus the transformed matter may be accumulated on both
ends of the amplitude of the movement, which hinders the effect of
the invention. On the other hands, when the surface roughness Ra of
the roller is in the range between 0.5 .mu.m and 0.5 .mu.m, and the
thread is moved in the direction of the axis of rotation of the
godet roller, accumulation of transformed spinning oil can be
prevented, thereby achieving the object of the invention. In the
range between 1 .mu.m and 3 .mu.m, the effect of the invention will
be more distinctive.
[0052] When the thread is reciprocated by moving the thread
converging guide, occurrence of a single filament breakage due to
abrasion as a result that filaments are separated during movement
of the thread guide may be prevented.
[0053] The thread converging guide here serves to fix up the
traveling thread during spinning and drawing of synthetic fiber,
and is, more preferably, a guide for fixing up the spinning
thread.
[0054] As the method of reciprocating the thread converging guide,
a method using means f or converting rotary motion into
reciprocating motion, such as a method of converting rotary motion
of the motor to reciprocating motion via a cam, a method of
conversing rotary motion of the motor to reciprocating motion via a
ball screw, a method of repeating linear motion of the cylinder to
obtain reciprocating motion, and a method of converting to
reciprocating motion via a gear provided on the stepping motor may
be employed.
[0055] In the case where the total fineness is not less than 200
dtex, the amount of spinning oil attached on the roller increases,
and the effect of the invention will be distinctive.
[0056] According to the invention, by setting the drawing tensile
stress during the last drawing step to at least 1.4 cN/dtex,
further distinctive effect may be obtained. In other words, when
the drawing tensile strength is not less than this value,
high-strength fiber not less than 6.0 cN/dtex can be obtained and
thus the effect of the transformed spinning oil is distinctive.
[0057] The thread used in the invention is preferably multi-thread
including at least two lines of thread. When it includes at least
two lines of thread, a single filament breakage in each line of
thread can be reduced, and thus a large interactive effect can be
obtained.
[0058] The width of reciprocating motion Y (mm) of the thread
preferably satisfies the following expression (1).
XF.ltoreq.Y.ltoreq.2(XP-XF) (1)
[0059] where;
[0060] XF is the width of the thread (mm), and XP is the thread
pitch (mm) between the adjacent threads.
[0061] This means the distance from the original position of the
thread to the position where the thread leaves the original
position, that is, the distance of movement of the thread having
the width XF until it reaches the position where the adjacent
thread was traveling before. Accordingly, not only effective
prevention of accumulated deposits is effected, but also abrasion
preventing effect on the surface of the godet roller is
increased.
[0062] Preferably, the cycle of the reciprocating motion of the
thread converging guide is not less than 5 seconds, and more
preferably, not less than 30 seconds from the viewpoint of
reduction of damage of the traveling thread on the godet roller and
of reduction of failure rate of the traversing device.
[0063] In the manufacture of the industrial fiber having the
drawing operation aiding unit, when the thread is reciprocated in
the direction of the axis of rotation of the godet roller while
synchronizing the thread converging guide for allowing the thread
to pass through before and/or after the thread is wound around the
godet roller located immediately after the spinning duct and one or
more drawing operation aiding units disposed between the plurality
of godet rollers, a single filament breakage caused by abrasion
between the thread and the drawing operation aiding unit may be
prevented.
[0064] The drawing operation aiding unit is a generic name of
devices for aiding to perform drawing operation smoothly, such as a
thread entangling device for preventing a single filament breakage
on the roller, a heat treatment cylinder for fixation of a drawing
point, a heat plate and a heat treatment cylinder for aiding
drawing operation.
[0065] The term "synchronization" in the invention means that the
thread converging guide and the drawing operation aiding unit have
a constant relationship during reciprocating motion, and
preferably, both of the thread converging guide and the drawing
operation aiding unit have a constant phase difference during
reciprocating motion.
[0066] The direction of the axis of rotation of the godet roller in
the invention means that one component of the movement vector is
parallel with the direction of the axis of rotation of the godet
roller.
[0067] The method for reciprocating the thread converging guide and
the drawing operation aiding unit includes the aforementioned
method of converting rotary motion of the motor to reciprocating
motion via a cam, a method of converting rotary motion of the motor
to reciprocating motion via a ball screw, a method of repeating
linear motion of the cylinder to obtain reciprocating motion, and a
method of converting to reciprocating motion via a gear provided on
the stepping motor.
[0068] As the method of synchronizing the thread converging guide
and the drawing operation aiding unit when using at least two
motors or cylinders, a method of detecting the position of the
revolving shaft of the motor or the cylinder and the position of
the thread by the use of a sensor to synchronize them, and a method
of taking outputs of a motor and of the cylinder out through a
shaft and transmitting it to the thread converging guide and the
drawing operation aiding unit via a cam or a gear to synchronize
them are preferable.
[0069] The thread used in the invention is preferably multi-thread
including at least two lines of thread. When the thread includes
two or more lines of thread, a single filament breakage in each
line of thread can be reduced, and thus a large interactive effect
can be obtained. In the case of multi-thread including at least two
lines of thread as described above, it is preferable to design in
such a manner that the thread converging guide is mounted on each
line of thread, that is, the same number as the number of the lines
of thread of the thread converging guide is provided, so that all
the lines of thread reciprocate simultaneously.
[0070] In the case where the drawing operation aiding unit is a
thread entangling device, it is necessary to position the thread at
the intersection of air blow, and accordingly, it is sensitive to
the displacement of the traveling thread. Therefore, by
reciprocating the thread converging guide and the thread entangling
device synchronously, the effect such as reduction of breakage of
filament becomes particularly distinctive.
[0071] By setting the width of the reciprocating motion Y (mm) of
the thread so as to satisfy the expression (1) described above,
accumulated deposits may be effectively prevented, and the effect
of preventing abrasion of the surface of the godet roller may be
increased.
[0072] Preferably, the cycle of the reciprocating motion of the
thread converging guide is not less than 5 seconds, and more
preferably, not less than 30 seconds from the viewpoint of
reduction of damage of the traveling thread on the godet roller and
of reduction of failure rate of the traversing device.
[0073] The thread traversing device of the invention will be
described referring to the drawings.
[0074] FIG. 1 is a schematic front elevation of the
spinning/drawing device provided with the thread traversing device
according to the invention; FIG. 2 is a side view of the same; FIG.
3 is a schematic perspective view of the second embodiment of the
thread traversing device of the invention; FIG. 4 is a schematic
perspective view showing the third embodiment; and FIG. 5 is a
block diagram of controlling means for a phase detecting means
according to the embodiment shown in FIG. 4.
[0075] The thread traversing device of the invention is to be used
directly in a method of manufacturing synthetic fiber described
above for reciprocating (traversing) the converging guide for
allowing the thread to pass through before and/or after the thread
is wound around the godet roller located immediately after the
spinning duct, and traversing one or plurality of the drawing
operation aiding unit synchronously therewith.
[0076] In other words, the thread traversing device of the
invention is a unit for preventing accumulation of extraneous
matters on the surface of the godet roller during spinning/drawing
of the thread of synthetic fiber, comprising means for
synchronously reciprocating a thread converging guide in the
direction of the axis of rotation for allowing the thread to pass
through before and/or after the thread is wound around the godet
roller located immediately after the spinning duct, and a drawing
operation aiding unit disposed between a plurality of godet
rollers.
[0077] As shown in FIG. 1 and FIG. 2, each of a plurality of
threads of synthetic fiber (23) is spun out from a spinning duct
(1), fed with spinning oil by the oiling rollers (2), passed
through the converging guides (6) mounted on the mounting board
(3), pre-stretched between the first godet roller (18) and the
second godet roller (19), drawn between the second godet roller
(19) and the third godet roller (20) in the first stage, then drawn
between the third godet roller (20) and the fourth godet roller
(21) in the second stage, relaxed between the fourth godet roller
(21) and the fifth godet roller (22), and wound on the winder
(W/D). Between the second godet roller (19) and the third godet
roller (20), there is provided a drawing operation aiding unit (5)
such as a thread confounding device. However, the positions of the
converging guide and the drawing operation aiding unit of the
invention are not limited thereto.
[0078] As shown in FIG. 2, there is provided means for moving the
converging guide (6) and the drawing operation aiding unit (5) in
parallel synchronously, that is, means comprising a driving motor
(4), a shaft (8) mounted on the driving motor (4) in the direction
of the axis of rotation of the godet roller, and two cams (7)
mounted on the shaft (8) and connected respectively to the
converging. guide (6) and the drawing operation aiding unit (5),
and such means can move the converging guide (6) and the drawing
operation aiding unit (5) accurately synchronously, so that the
thread (23) reciprocates in the direction of the axis of rotation
of the godet roller with respect to the traveling thread.
[0079] FIG. 3 shows the second embodiment of the thread traversing
device according to the invention. In this device, the shaft (8) is
mounted on the driving motor (4). Though the driving motor (4) and
the shaft may be in direct contact with each other, it is
preferable to provide a speed reducer (9) therebetween as shown in
the figure since a desired rotational speed can be obtained, and in
this arrangement, the traveling thread can be moved at sufficiently
slow speed so as not to be damaged.
[0080] The shaft (8) mounted in the direction of the axis of
rotation of the godet roller is provided with two cams (7a, 7b),
and the drawing operation aiding unit (5) mounted on the drawing
operation aiding unit mounting board (10) and the converging guide
(6) mounted on the converging guide mounting board (3) are in
contact with the respective cams (7a, 7b) via the sliding rollers
(13a, 13b) provided respectively on the mounting board (10, 3).
[0081] The drawing operation aiding unit mounting board (10) is
mounted on the stationary slide rail (11) so as to slide along the
length of the shaft (8).
[0082] In addition, the converging guide mounting board (3) is
mounted on the slide bearing (12), which is also stationary, by the
use of a sliding shaft (14), so as to slide along the length of the
shaft (8).
[0083] Therefore, with the arrangement described above, the
converging guide mounting board (3) and the drawing operation
aiding unit mounting board (10) are slid along the length of the
shaft (8) respectively by the slide bearing (12) and the sliding
shaft (14) and by the slide rail (11) in association with the
movement of the sliding rollers (13a, 13b) provided on the
converging guide mounting board (3) and the drawing operation
aiding unit mounting board (10) along the grooves on the two cams
(7a, 7b) which is rotated by the driving motor (4), and the
converging guide (6) and the drawing operation aiding unit (5) are
reciprocated synchronously in the direction of the axis of rotation
of the godet roller.
[0084] FIG. 4 shows the third embodiment of the thread traversing
device of the invention. In this device, the converging guide (6)
and the drawing operation aiding unit (5) are provided respectively
on the separate shafts (8a, 8b)mounted respectively on the separate
motors (4a) and (4b) via the separate cams (7a, 7b) respectively so
as to make a reciprocating motion, and phase detecting means for
detecting that the respective cams (7a, 7b) are rotated to the
prescribed positions are mounted respectively, so that the control
panel (17) shown in FIG. 5 synchronizes the converging guide (6)
and the drawing. operation aiding unit (5) by stopping the rotation
of the shaft provided with the one of the phase detecting means
when the prescribed position is detected by one of the phase
detecting means, and rotating the stopped shaft when the prescribed
position is detected by the other one of the phase detecting
means.
[0085] In other words, in the third embodiment, the converging
guide (6) and the drawing operation aiding unit (5) are
reciprocated in the same manner as means in the first embodiment
other than the point that they are driven by the separate driving
motors (4a, 4b).
[0086] The phase detecting means in the third embodiment may be
constructed as follows. The cams (7a, 7b) are provided with
detected portions (16a, 16b) of the proximity sensors respectively,
and the proximity sensors (15a, 15b) are mounted respectively on
the portions that are not rotated by the driving motors (4a, 4b)
such as speed reducers (9a, 9b). The positions to which these
proximity sensors (15a, 15b) are mounted are discretionary as far
as they are not rotated by the driving motors (4a, 4b). For
example, they may be mounted on the bearing portions as well as the
speed reducers (9a. 9b), or may be mounted on the body of the
drawing machine.
[0087] When the respective cams (7a, 7b) are rotated and the
detected portion (16a) and the proximity sensor (15a) or the
detected portion(16b)and the proximity sensor(15b)face toward each
other, a signal supplied from the proximity sensor(15a,15b) is
reflected on the detected portion (16a,16b) and detected by the
proximity sensor (15a,15b).
[0088] When the proximity sensor detected the opposed detected
portion, a detected signal is supplied to the control panel (17).
The control panel (17) is, as shown in FIG. 5, connected to the
proximity sensor (15a) and the proximity sensor (15b), and to the
driving motor (4a) and the driving motor (4b),and constructed in
such a manner that when a detected signal is supplied by one of the
proximity sensors (15a) for example, the rotation of the driving
motor (4a) provided with the one of the proximity sensors (15a) is
stopped, and when a detected signal is supplied by the other
proximity sensor (15b), the stopped driving motor (4a) is
rotated.
[0089] The proximity sensor to be employed in the invention is
preferably a photosensitive proximity sensor. However, as far as it
achieves the desired object, it may be of capacitance type or
magnetic type.
[0090] According to the third embodiment, the converging guide (6)
and the drawing operation aiding unit (5) reciprocate in accurately
synchronously. When there are provided a plurality of drawing
operation aiding units, the rotation is stopped sequentially from
the driving motor on which the proximity sensor which supplied a
detecting signal first is mounted, and when the last detecting
signal was supplied within one to-and-fro motion, all the driving
motor which had stopped must simply be driven by the control
panel.
[0091] The third embodiment is effective when both of the
converging guide and the drawing operation aiding unit cannot be
driven easily by one shaft.
[0092] Preferably, the cycle of the reciprocating motion of the
thread traversing device according to the invention is at least 5
seconds, and more preferably, at least 30 seconds from the
viewpoint of reduction of damage of the traveling thread and of
reduction of failure rate of the traversing device.
[0093] In addition, in order to convert a rotational motion of the
shaft (8) into a reciprocating motion, a ball screw or a gear may
be employed instead of the cam (7), and it is not limited thereto
as far as it can achieve the desired object. However, the use of
cam is preferable from the viewpoints of the cost and ease of
access. The traversing width of the converging guide and the
drawing operation aiding unit may be varied as desired by varying
the shape of the cam, and the converging guide and the drawing
operation aiding unit may be synchronously reciprocated with a
constant phase difference by mounting the respective cams being in
contact with both of them with the grooves thereof shifted with
respect to the shaft.
[0094] In addition, determining the shape of the cam such that the
width Y (mm) of the reciprocating motion of the thread satisfies
the expression (1) described above may lead not only to effective
prevention of the accumulated deposits, but also to increased
effect to prevent abrasion of the surface of the godet roller.
[0095] In the converging guide and the drawing operation aiding
unit according to the invention, the number of lines of thread is
not limited, but preferably, the multi-thread is used. When
multi-thread is used, stain on the godet rollers appears
distinctively, and thus the objective effect can be realized
distinctively.
[0096] The invention will bear more preferably effect when the
tread entangling unit is used as a drawing operation aiding unit.
The reason is that the thread entangling unit requires that the
thread is positioned at the intersection of air blow, and thus it
is sensitive to the displacement of the traveling thread.
[0097] As means for reciprocating the converging guide and the
drawing operation aiding unit, a fluid cylinder or the like may be
used instead of means using the driving motor, the shaft and the
cam. However, in terms of repair of the unit or the cost, the
method described above is more preferable.
[0098] As is described thus far, according to a method of
manufacturing synthetic fiber and the thread traversing unit
according to the invention, the godet roller may be maintained in
the initial state for a long time by preventing accumulation of
extraneous matters on the godet roller, the rate of operation and
productive efficiency may be increased by reducing the number of
times the machine has to be stopped for removing extraneous
matters, and problems such as a single filament breakage or
generation of fuzz may be solved and high-strength synthetic fiber
of good quality and appearance may be manufactured.
[0099] Among others, it is more effective when manufacturing
industrial high-strength fiber by a high-speed direct
spinning/drawing method, because accumulation of extraneous matters
on the godet roller is prevented.
[0100] [Embodiment]
[0101] The invention will be described in detail referring to
embodiments and comparative examples.
[0102] The evaluation of each characteristic in the following
embodiments was made in the following methods.
[0103] [Surface Roughness]The surface roughness of the godet roller
was calculated, in accordance with JISB0601, by obtaining the
roughness curve on the surface of the godet roller from the section
curve measured by the use of Surfcorder SE1700 manufactured by
Kosaka Lab. with a sensing pin of 2 .mu.m radius, a feed rate of
0.5 mm, and a cut-off of 0.8 mm or 2.5 mm.
[0104] [Melting Point]
[0105] The melting point was obtained from a trace of variations in
heat quantity obtained by melting 2 mg of sample by the use of
DSC-7 type manufactured by Perkin Elmer Inc., quenching and
solidifying it by liquid nitrogen, and scanning the sample at the
speed of 20.degree. C./min. Temperature at the maximum endothermic
peak was regarded as the melting point. The melting point of the
drawn yarn obtained by the invention was 250.degree. C.
[0106] [Temperature of Godet Roller]
[0107] The temperature on the surface of the godet roller was
measured by the use of a contact thermometer.
[0108] [Tensile Stress of Drawing]
[0109] The tensile stress of drawing was obtained by measuring a
tensile stress of the traveling thread between the third godet
roller and the fourth godet roller by the use of HS-3000, which is
a tension meter manufactured by EIKO SOKKI, and then divided by the
total olenier of the drawn thread.
[0110] [A single filament breakage]
[0111] The number of breakage was counted by a single filament
breakage detector, and expressed by the number of breakage per
10,000,000 m.
[0112] [Contamination of the Roller]
[0113] Stain on the roller along the thread passage was visually
observed every 24 hours, and classified into "lightly stained"
marked with A, "normally stained" marked with B, "heavily stained
and causing significant shaking of the tread" marked with C.
[0114] [Breakage of Thread]
[0115] The number of times of breakage of the thread per day was
counted.
[0116] [Strength of yarn]
[0117] The strength of yarn was measured based on JIS L-1017
(1995). The S-S curve was obtained using Tensilon tensile tester
manufactured by Orientec Co., with the sample having the length of
25 cm at the tensile speed of 30 cm/min., and read the value from
the obtained S-S curve.
[0118] [Heat Shrinkage]
[0119] A skein of obtained yarn was provided and was left stand for
at least 24 hours in the temperature regulated room of 20.degree.
C., 65% RH, and then was measured with a load which corresponds to
0.1 g/d of the sample applied thereon. After leaving the sample
having a length of L0 stand in the oven at 150.degree. C. for 30
minutes without any tension applied thereon, it was taken out of
the oven and left stand for four hours in the temperature regulated
room. Then the same load as described above was applied thereon
again, and the length L1 was measured. Then, the rate of shrinkage
by dry heat was calculated using the following expression.
Rate of heat shrinkage (%)={(L0-L1)/L0}.times.100
[0120] [Embodiment 1]
[0121] Polyethylene terephthalate chip having intrinsic viscosity
(IV) of 1.19 was fed to a extruder type melt spinning machine for
spinning two lines of thread simultaneously. It was filtered
through a metallic filter having a pore of 15 .mu.m and spun
through a spinneret having 72 holes at a spinning temperature of
300.degree. C.
[0122] Then, spun thread was passed under the atmosphere at high
temperature of 300.degree. C. for 350 mm from the surface of the
spinneret, and then quenched and solidified by blowing cold air at
about 20.degree. C. thereon. Subsequently, it is applied with
spinning oil by an oiling roller, and routed to the first godet
roller. The obtained undrawn thread was, without being wound
completely, pre-stretched by 1.06 times in length between the first
godet roller and the second godet roller, then drawn by 3.70 times
in length between the second godet roller and the third godet
roller, drawn by 1.40 times in length between the third godet
roller and the fourth godet roller, relaxed by 1.0% between the
fourth godet roller and the fifth godet roller, and finally wound
on the winder two lines of thread simultaneously at the speed of
3300 m/min., to obtain drawn yarn. The third and fourth godet
rollers used here had Cr.sub.2O.sub.3 coated surfaces of Ra=1.0
.mu.m.
[0123] The temperatures of the respective godet rollers were
70.degree. C. for the first godet roller, 100.degree. C. for the
second godet roller, 120.degree. C. for the third godet roller,
240.degree. C. for the fourth godet roller, no heating for the
fifth godet roller. The numbers of turns of the thread for the
respective godet rollers were, three turns for the first godet
roller, three turns for the second godet roller, four turns for the
third godet roller, 7 turns for the fourth godet roller, and five
turns for the fifth godet roller. A single filament breakage
detector is mounted for the thread being wound on the fifth godet
roller to count the number of breakage, and the number of breakage
of the thread was evaluated as well.
[0124] In the drawing/heat treatment process described above, the
converging guide (6) provided forwardly of the first godet roller
(18) in FIG. 1 was reciprocated, and the thread (23) was traversed
on the godet roller in the direction of the axis of rotation of the
godet roller. The converging guide employed was configured as shown
in FIG. 3.
[0125] The thread width XF was 5.0 mm, the thread pitch XP with
respect to the adjacent thread was 15.0 mm, and the value of
2(XP-XF) was 20 mm.
[0126] As a mechanism for reciprocating the converging guide, the
one mounted on the shaft for rotating a cam connected to the
converging guide by the driving motor via the shaft, and
reciprocates the converging guide in the direction of the axis of
rotation of the godet roller along the groove on the cam was
employed.
[0127] By setting the number of revolution of the shaft to 2 rpm by
the use of the driving motor and the speed reducer, the cycle of a
reciprocating motion was set to 30 seconds and the traverse width
on the winding roller to 16 mm respectively. These conditions and
the results of evaluation of stain on the roller, a single filament
breakage, thread breakage, heat shrinkage of the obtained yarn are
shown in Table 1.
[0128] In Embodiment 1, as a result of traversing the thread on the
godet roller, the effects such that the condition of the surface of
the godet roller can be maintained in the lightly stained state
until the fourth day, and the number of occurrence of a single
filament breakage or of thread was distinctively small were
discernible.
[0129] [Embodiment 2]
[0130] The thread traversing device used in Embodiment 1 was
replaced with the one having a structure shown in FIG. 3. The
position of the converging guide, the shape of the cam, the number
of revolution of the shaft were the same as in Embodiment 1. The
drawing operation aiding unit was disposed between the second godet
roller and the third godet roller, and reciprocated synchronously
with the converging guide. These conditions and the results of
evaluation of stain on the roller, a single filament breakage, and
thread breakage are shown in Table 1.
[0131] [Embodiment 3]
[0132] The thread traversing unit used in Embodiment 2 was replaced
with the one having a structure shown in FIG. 4. The position of
the drawing operation aiding unit (5) was between the second godet
roller and the third godet roller in FIG. 1. The shape of the cam
and the number of revolution of the shaft were the same as in
Embodiment 1. These conditions and the results of evaluation of
stain on the roller, a single filament breakage, and thread
breakage are shown in Table 1.
[0133] As a result, the same preferable results as in Embodiment 2
were discernible as shown in Table 1.
[0134] [Embodiment 4-Embodiment 8]
[0135] The conditions in Embodiment 2 were changed as shown in
Table 1. The obtained results are shown in Table 1.
[0136] [Comparative Example 1]
[0137] Melt-spinning process was performed on polyethylene
terephthalate under the same conditions as Embodiment 1 other than
those shown in Table 1, and the thread was wound on each godet
roller and taken up by the winder without reciprocating the
converging guide. The results of evaluation of stain on the roller,
a single filament breakage, and thread breakage are shown in Table
1. Consequently, in the case where the thread was not traversed on
the godet roller, the surface of the roller was maintained in
lightly stained condition until the second day, but occurrence of a
single filament breakage was suddenly increased on the third day,
and thereafter, the thread could not taken up and occurrence of
thread breakage was increased significantly.
[0138] [Comparative Example 2-Comparative Example 6]
[0139] Melt-spinning process was performed on PET under the same
conditions as in Embodiment 2 other than the conditions shown in
Table 1. The results are shown in Table 1.
1TABLE Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- Embodi- ment
1 ment 2 ment 3 ment 4 ment 5 ment 6 ment 7 Presence of Air guide N
Y Y Y Y Y Y Presence of Traversing Unit Y Y Y Y Y Y Y Traversing
Width on spinning Roller 16 16 16 8 16 16 8 (mm) Reciprocating
Cycle (second) 30 30 30 30 30 30 30 Stain on Roller 1st day
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. 2nd day .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. 3rd day .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. 4th day .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. 5th day
.DELTA. .DELTA. .DELTA. .DELTA. .DELTA. .DELTA. .largecircle. A
single filament breakage 1st day 5 4 4 4 4 4 5 (points/10000000 m)
2nd day 9 8 9 10 9 10 6 3rd day 15 13 13 19 14 18 9 4th day 22 20
21 26 21 26 15 5th day 29 25 25 32 25 30 20 Thread Breakage
(times/day) 0.2 0.2 0.2 0.2 0.2 0.2 0.2 Third and Fourth Godet
Roller Ra (.mu.m) 1 1 1 1 0.5 4 1 Temperature of Fourth Godet
Roller (.degree. C. 240 240 240 240 240 240 240 Magnification of
Drawing (times) 5.2 5.5 5.5 5.5 5.5 5.5 5.2 denier (dtex) 1100 1100
1100 1100 1100 1100 230 Strength (cN/dtex) 7.0 7.5 7.5 7.5 7.5 7.5
7.0 Tensile Stress (cN/dtex) 1.6 1.7 1.7 1.7 1.7 1.7 1.6 Heat
Shrinkage (%) 6.2 6.7 6.5 6.5 6.6 6.5 6.2 Embodi- Comp. Comp. Comp.
Comp. Comp. Comp. ment 8 Ex. 1 Ex. 2 Ex. 3 Ex. 4 Ex. 5 Ex. 6
Presence of Air guide Y N Y Y Y Y Y Presence of Traversing Unit Y N
N Y Y N Y Traversing Width on spinning Roller 8 0 0 16 16 0 8 (mm)
Reciprocating Cycle (second) 5 -- -- 30 30 30 3 Stain on Roller 1st
day .largecircle. .largecircle. .largecircle. .largecircle.
.largecircle. .largecircle. .DELTA. 2nd day .largecircle.
.largecircle. .largecircle. .largecircle. .largecircle. .DELTA. X
3rd day .largecircle. X X .largecircle. .largecircle. X -- 4th day
.DELTA. -- -- .largecircle. .DELTA. -- -- 5th day X -- --
.largecircle. X -- -- A single filament breakage 1st day 7 12 5 4 4
5 35 (points/10000000 m) 2nd day 12 28 20 7 25 21 60 3rd day 19 60
52 12 32 60 -- 4th day 32 -- -- 28 36 -- -- 5th day 60 -- -- 30 60
-- -- Thread Breakage (times/day) 0.3 1.0 1.0 0.2 0.5 1.4 -- Third
and Fourth Godet Roller Ra (.mu.m) 1 1 0.3 1 1 6.0 -- Temperature
of Fourth Godet Roller (.degree. C. 240 240 240 240 240 160 240
Magnification of Drawing (times) 5.5 4.9 4.9 4.9 4.7 4.8 4.8 denier
(dtex) 1100 1100 1100 1100 1100 1100 1100 Strength (cN/dtex) 7.5
6.0 6.0 6.0 5.8 5.8 5.8 Tensile Stress (cN/dtex) 1.7 1.4 1.4 1.4
1.3 1.4 1.4 Heat Shrinkage (%) 6.5 5.5 5.5 15.5 4.5 5.5 5.5
.largecircle.= A .DELTA.= B X = C *N = no Y = yes
[0140] [Industrial Applicability]
[0141] As is described thus far, according to a method of
manufacturing synthetic fiber and a thread traversing device of the
invention, by preventing accumulation of extraneous matters on the
godet roller, the godet roller can be maintained in the initial
state for a long time and thus the number of times the machine has
to be stopped for removing extraneous matter can be reduced to
increase the rate of operation and productive efficiency. In
addition, problems such as thread breakage or generation of fuzz
are solved and thus high-strength synthetic fiber of excellent
quality and appearance can be manufactured. Especially, when
manufacturing industrial high-strength fiber by high-speed direct
spinning/drawing method, accumulation of extraneous matter on the
godet roller can be prevented, thereby being preferably applicable
to a manufacturing process of industrial high-strength synthetic
fiber.
* * * * *