U.S. patent application number 11/433532 was filed with the patent office on 2007-10-18 for polyethylene terephthalate filament having high tenacity for industrial use.
This patent application is currently assigned to HYOSUNG Corporation. Invention is credited to Dae-Hwan Cho, Kyu-Chan Han, Dong-Seok Shim.
Application Number | 20070243378 11/433532 |
Document ID | / |
Family ID | 38294149 |
Filed Date | 2007-10-18 |
United States Patent
Application |
20070243378 |
Kind Code |
A1 |
Cho; Dae-Hwan ; et
al. |
October 18, 2007 |
Polyethylene terephthalate filament having high tenacity for
industrial use
Abstract
A polyethylene terephthalate monofilament obtained by spinning a
polyethylene terephthalate chip having an intrinsic viscosity of
0.8 to 1.3, which gives a stress-strain curve exhibiting an
elongation of less than 2.5% at an initial stress of 2.0 g/d, with
an initial modulus value of 80 to 160 g/d, an elongation of 7.5% or
less in a stress range of from 2.0 g/d to 9.0 g/d, and an
elongation of at least 2.0% or more in a stress range of from 10.0
g/d to the point of break, is provided.
Inventors: |
Cho; Dae-Hwan; (Kyonggi-do,
KR) ; Han; Kyu-Chan; (Kyonggi-do, KR) ; Shim;
Dong-Seok; (Kyonggi-do, KR) |
Correspondence
Address: |
NIXON & VANDERHYE, PC
901 NORTH GLEBE ROAD, 11TH FLOOR
ARLINGTON
VA
22203
US
|
Assignee: |
HYOSUNG Corporation
Anyang-si
KR
|
Family ID: |
38294149 |
Appl. No.: |
11/433532 |
Filed: |
May 15, 2006 |
Current U.S.
Class: |
428/375 |
Current CPC
Class: |
D01D 5/084 20130101;
D01D 5/16 20130101; Y10T 428/2913 20150115; Y10T 428/2933 20150115;
D01F 6/62 20130101; Y10T 428/2969 20150115 |
Class at
Publication: |
428/375 |
International
Class: |
D02G 3/00 20060101
D02G003/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 14, 2006 |
KR |
10-2006-0033877 |
Claims
1. A polyethylene terephthalate monofilament, which is obtained by
spinning a polyethylene terephthalate chip having an intrinsic
viscosity of 0.8 to 1.3, wherein the polyethylene terephthalate
monofilament gives a stress-strain curve exhibiting an elongation
of less than 2.5% at an initial stress of 2.0 g/d, with an initial
modulus value of 80 to 160 g/d, an elongation of 7.5% or less in a
stress range of from 2.0 g/d to 9.0 g/d, and an elongation of at
least 2.0% or more in a stress range of from 10.0 g/d to the point
of break.
2. The polyethylene terephthalate monofilament according to claim
1, wherein the linear density of the polyethylene terephthalate is
3 to 30 denier.
3. A polyethylene terephthalate multifilament, which is obtained by
aggregating 50 to 40,000 polyethylene terephthalate monofilaments
according to claim 1.
4. The polyethylene terephthalate multifilament according to claim
3, which is obtained by aggregating 192 or 384 polyethylene
terephthalate monofilaments.
5. The polyethylene terephthalate multifilament according to claim
3, wherein the strength of the polyethylene terephthalate
multifilament has a stress of 10 to 13 g/d.
6. The polyethylene terephthalate multifilament according to claim
3, wherein the elongation at break of the polyethylene
terephthalate multifilament is 9.5 to 13.5%.
7. An industrial product selected from the group consisting of
industrial rope, reinforcement material for construction, webbing
and seatbelt, all of which comprise the polyethylene terephthalate
multifilament according to claim 3.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a polyethylene
terephthalate monofilament fiber which gives a stress-strain curve
exhibiting an elongation of at least 2.0% or more in a stress range
of from 10.0 g/d to the point of break. The monofilament fiber
according to the invention is characterized by high tenacity, high
modulus and low strain, and thus can be used for the production of
high tenacity polyester fiber for industrial use, which is used as
the material for industrial rope, reinforcement material for
construction, webbing or seatbelt.
[0003] 2. Description of the Related Art
[0004] As a useful conventional method for enhancing the tenacity
of polyester fibers for industrial use, there is available a method
of melting a high viscosity chip having an intrinsic viscosity of
1.0 or greater, heating the melt polymer to a temperature of
310.degree. C. to sufficiently melt the polymer, solidifying the
polymer at a quenching temperature of 15 to 18.degree. C. in a hood
of 280 mm long at a hood temperature of 340.degree. C., winding the
polymer at low speed on godet rollers to obtain undrawn yarn,
drawing the undrawn yarn directly in a first step and a second step
up to a draw ratio of 6.0, and then relaxing the drawn yarn to
finally wind the drawn yarn. Here, the characteristic of high
tenacity is obtained by decreasing the degree of orientation of the
undrawn yarn through low speed winding, and by drawing the undrawn
yarn at a high draw ratio. The polyester yarn produced by the
conventional method as described above has a modulus value of 60
g/d to 100 g/d, a stress of 9.5 g/d or less, and an elongation at
break of 13 to 18%.
[0005] When the draw ratio is increased to obtain a fiber of higher
tenacity using such conventional spinning technology, a processing
problem of yarn break during spinning and fluffing frequently
occur, resulting in poor post-processing properties. Therefore, the
conventional technology leads to an increase in the production
costs and lowering of the product quality, and thus it is difficult
to obtain high tenacity yarns therefrom.
SUMMARY OF THE INVENTION
[0006] Accordingly, it is an object of the present invention to
provide a polyethylene terephthalate monofilament fiber which has a
stress-strain profile exhibiting an elongation of at least 2.0% or
more in a stress range of from 10.0 g/d to the point of break.
[0007] The fiber according to the invention is produced by a method
of adjusting the areas of contact between the yarn and the godet
rollers, on which initial drawing and secondary drawing are
performed, so as to increase the draw ratio, thus enabling drawing
at a draw ratio of 6.5, which is higher than the conventionally
achieved draw ratio of 6.0.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic diagram illustrating the production
process for the polyethylene terephthalate filament according to
the present invention;
[0009] FIG. 2 is a graph showing the stress-strain curves for
monofilaments of the 1500D polyethylene terephthalate filament of
the present invention and a conventional 1500D polyethylene
terephthalate filament; and
[0010] FIG. 3 is a graph showing the stress-strain curves for
monofilaments of the 1000D polyethylene terephthalate filament of
the present invention and a conventional 1000D polyethylene
terephthalate filament.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] According to a preferred embodiment of the present
invention, a polyethylene terephthalate monofilament having an
intrinsic viscosity of 0.8 to 1.3 gives a stress-strain curve
exhibiting an elongation of less than 2.5% at an initial stress of
2.0 g/d, with an initial modulus value of 80 to 160 g/d, an
elongation of 7.5% or less in a stress range of from 2.0 g/d to 9.0
g/d, and an elongation of at least 2.0% or more in a stress range
of from 10.0 g/d to the point of break.
[0012] According to another embodiment of the invention, the
polyethylene terephthalate monofilament has a linear density of 3
to 30 denier.
[0013] According to another embodiment of the invention, a
multifilament consisting of an aggregate of 50 to 40,000
polyethylene terephthalate monofilaments is provided.
[0014] According to another embodiment of the invention, a
multifilament consisting of an aggregate of 192 or 384 polyethylene
terephthalate monofilaments is provided.
[0015] According to another embodiment of the invention, the
multifilament has a stress of 10 to 13 g/d.
[0016] According to another embodiment of the invention, the
multifilament has an elongation at break of 9.5 to 13.5%.
[0017] The invention provides industrial products such as
industrial rope, reinforcement material for construction, webbing
or seatbelt, all of which comprise the multifilament.
[0018] According to the invention, in the case of a high tenacity
polyethylene terephthalate yarn used for industrial rope,
reinforcement material for construction, webbing or seatbelt, the
stress-strain curve of the polyethylene terephthalate monofilament
is adjusted for the purpose of minimizing the initial elongation
against the impact occurring, initially under an external force.
The stress-strain curve of the polyethylene terephthalate
monofilament measured at ambient temperature preferably exhibits an
elongation of less than 2.5% at an initial stress of 2.0 g/d, with
an initial modulus value of 80 to 160 g/d, an elongation of 7.5% or
less in a stress range of from 2.0 g/d to 9.0 g/d, and an
elongation of at least 2.0% or more in a stress range of from 10.0
g/d to the point of break.
[0019] In the case of using as industrial rope or reinforcement
material for construction, the polyethylene terephthalate
monofilament should have high initial modulus and less drawing
under initially applied force, so as to prevent sudden deformation.
In order to obtain such material, the polyethylene terephthalate
monofilament of the invention preferably has an elongation of less
than 2.5% at an initial stress of 2.0 g/d, and an initial modulus
value of 80 to 160 g/d. If the monofilament has an elongation of
2.5% or greater at an initial stress of 2.0 g/d, or has a lower
modulus value, sudden deformation of the monofilament makes it
difficult to obtain a stress-supporting or reinforcing effect.
[0020] Furthermore, the polyethylene terephthalate monofilament
used for the production of such material has preferably an
elongation of 7.5% or less in the stress range of from 2.0 g/d to
9.0 g/d. When the monofilament has an elongation of 7.5% or more,
the dimensional stability of the monofilament is decreased,
resulting in large deformation and the monofilament can be hardly
used as industrial reinforcement material or rope.
[0021] In addition, for the purpose of minimizing the storage space
through miniaturization of industrial products such as industrial
rope, reinforcement material for construction, webbing or seatbelt,
it is preferable for the polyethylene terephthalate monofilament of
the invention to draw with an elongation of at least 2.0% or more
in the stress range of from 10.0 g/d to the point of break. This is
because, when the monofilament has an elongation of less than 2.0%
from 10.0 g/d to the point of break, the ability of the filament
for absorbing the maximum tensile load is insufficient, and thus,
industrial products produced from small amounts of woven yarns
would have insufficient tensile strength.
[0022] The present invention will be described in detail with
reference to the attached drawings.
[0023] In FIG. 1, a polyester chip having an intrinsic viscosity in
the range of 0.80 to 1.30 is melted in an extruder 11, in which the
temperature condition is set lower. Here, the temperature of the
melted polymer is set to 290 to 305.degree. C., and heat is applied
to maintain the temperature of the gear pump 12. At this time, the
temperature of the gear pump 12 is adjusted to be low, so that the
temperature of the polymer passing through the gear pump 12 is
maintained at 295 to 310.degree. C. Thermal decomposition due to
exotherm or high temperature as a result of the temperature
adjustment should be suppressed as far as possible, so that the
characteristic properties of the polymer itself are not lost. The
diameter of the nozzle holes of a spinneret 13 is set to 0.5 to 0.8
.phi., while the ratio of the length to the diameter (L/D) of a
hole of the spinneret 13 is set to 2 to 3, in order to maintain the
spinning draft at a constant level, and to impart high
stretchability to the polymer on the godet roller. The length of a
hood heater 14 is extended to 320 to 500 mm, and the temperature of
the hood heater 14 is raised to 350 to 400.degree. C., so that an
atmosphere allowing the spun yarn to have a non-crystalline and
non-oriented structure is rendered inside the hood. To this
non-crystalline, non-oriented yarn thus formed, air at a
temperature of 15 to 18.degree. C. is supplied through a
high-throughput air supplying inlet 151 and discharged through an
air outlet 152 in the cooling zone 15, thereby allowing rapid
quenching of the non-crystalline, non-oriented yarn. Here, the
amount of air supplied is set to 80 to 110 mmAq, while the amount
of air discharged is set to 90 to 120 mmAq. The non-crystalline,
non-oriented yarn which has been solidified is subjected to oiling
to an appropriate extent by using an oiling apparatus 16.
Thereafter, a guide of a specific form is applied to the second
godet rollers (GR) 172 so as to adjust the area of contact between
the multifilament yarn and the roller surface of the second GR to
about 1,000 to 15,000 mm.sup.2, so that primary drawing is
performed smoothly at the second GR 172 and the third GR 173. Then,
a guide is applied prior to the third GR 173 in order to maintain
the spread of the yarn constant on the third GR 173, so as to
adjust the area of contact between the multifilament yarn and the
roller surface of the third GR 173 to about 5,000 to 25,000
mm.sup.2, so that secondary drawing is performed smoothly on the
third GR 173 and the fourth GR 174. The multifilament is relaxed
between the fourth GR 174 and the fifth GR 175 and then wound up on
a winder 18.
[0024] FIG. 2 is a graph showing the stress-strain curves for the
monofilaments of the 1500D polyethylene terephthalate filament of
the present invention and a conventional 1500D polyethylene
terephthalate filament.
[0025] FIG. 3 is a graph showing the stress-strain curves for the
monofilaments of the 1000D polyethylene terephthalate filament of
the present invention and a conventional 1500D polyethylene
terephthalate filament.
[0026] According to the present invention, the stress-strain curve
of a polyethylene terephthalate monofilament can be adjusted to
minimize the initial elongation of the industrial high tenacity
yarn caused by the impact initially applied by external force. The
polyethylene terephthalate monofilament of the invention may result
in a stress-strain curve which exhibits an elongation of less than
2.5% at an initial stress of 2.0 g/d, with an initial modulus value
of 80 to 160 g/d, an elongation of 7.5% or less in a stress range
of from 2.0 g/d to 9.0 g/d, and an elongation of at least 2.0% or
more in a stress range of from 10.0 g/d to the point of break.
[0027] According to the invention, the process which is used for
obtaining such stress-strain curve comprises the steps of rendering
an atmosphere in the hood such that a polyethylene terephthalate
monofilament can have a maximally non-crystalline and non-oriented
structure while passing through the hood heater 14, and rapidly
quenching the non-crystalline, non-oriented yarn thus formed in the
cooling zone 15 to maintain the non-crystalline and non-oriented
state as far as possible, so as to allow operation with a high draw
ratio.
[0028] The factor which highly affects the stress-strain curve for
the monofilament of the invention is the areas of contact between
the yarn and the godet rollers, on which the initial primary
drawing and secondary drawing occur. As the contact areas are
adjusted, a preferable stress-strain curve for the monofilament of
the invention is obtained. The polyethylene terephthalate filament
which has passed through the cooling zone 15 has constant contact
areas with the surfaces of the second GR 172 and the third GR 173,
which highly affect the initial primary drawing and the secondary
drawing. The area of contact between the multifilament yarns with
the surface of the godet rollers used for the initial primary
drawing is preferably 4,000 to 8,000 mm.sup.2, while the area of
contact between the multifilament yarns with the surface of the
godet rollers used for the secondary drawing is preferably 14,000
to 18,000 mm.sup.2. When the area of contact between the
multifilament yarns and the surface of the godet rollers used for
the initial primary drawing is less than 4,000 mm.sup.2, or when
the area of contact between the multifilament yarn and the surface
of the godet rollers used for the secondary drawing is less than
14,000 mm.sup.2, uniform heat transfer is not achieved between the
multifilaments. Furthermore, non-uniformity of the flowing agent
causes reduction in the stretchability, and it is difficult to
obtain a preferable stress-strain curve for the monofilament of the
invention. On the contrary, when the area of contact between the
multifilament yarn and the surface of the godet rollers used for
the initial primary drawing is larger than 8,000 mm.sup.2, or when
the area of contact between the multifilament yarn and the surface
of the godet rollers used for the secondary drawing is larger than
18,000 mm.sup.2, there are problems such as generation of fluff due
to contact between filaments, and tar generation. Therefore, the
contact areas should be suitably adjusted in order for the
non-crystalline, non-oriented monofilament to obtain the maximum
stretchability.
[0029] There are many factors affecting the area of contact between
multifilament yarn and godet roller surface. The area of contact
increases proportionally to the number of winding (number of turn)
of the filament wound on the godet rollers for drawing. That is,
the number of winding can be adjusted to adjust the area of
contact. Another important factor is that a guide having a certain
form is applied to maintain the spread of the yarn between the
godet rollers constant, so that the yarn width of the yarn wound on
the godet rollers can be adjusted. For example, if the guide takes
a form of a narrow V-shaped groove, the yarn width is reduced, and
eventually the contact area is reduced. If the guide takes a flat
form, the yarn width is increased, and the contact area is
increased. Another factor for adjusting the contact area is the
drawing tension of the roller, drawing temperature, amount of
flowing agent, and the like.
[0030] A preferable stress-strain curve of the monofilament of the
invention can be obtained by adjusting the area of contact of the
multifilament yarn with the surface of the second GR 172, which
largely affects the primary drawing, to 4,000 to 8,000 mm.sup.2,
while adjusting the area of contact of the multifilament yarn with
the surface of the third GR 173, which are the godet rollers used
for the secondary drawing, to 14,000 to 18,000 mm.sup.2, by
organically combining various factors.
[0031] The polyethylene terephthalate multifilament obtained by
aggregating 50 to 40,000 polyethylene terephthalate monofilaments
produced through such process, has good spinnability and thus is
advantageous in the aspects of external appearance and fluffing.
Also, the polyethylene terephthalate multifilament has a stress of
10 to 13 g/d, a modulus of 110 to 140 g/d, and an elongation at
break of 9.5 to 13.5% or less, and thus can be widely used as an
industrial polyester fiber which is useful for industrial rope,
reinforcement material for construction, webbing and seatbelt.
[0032] The property evaluations in the following Examples and
Comparative Examples were performed as follows.
[0033] 1) Intrinsic Viscosity (I.V.)
[0034] 0.1 g of a sample is dissolved in a reagent comprising a
mixture of phenol and 1,1,2,2-tetrachloroethaanol at a weight ratio
of 6:4 at 90.degree. C. for 90 minutes, and then the solution is
transferred to an Ubbelohde viscometer, which is then maintained in
a constant temperature bath at 30.degree. C. for 10 minutes. The
time in seconds taken by the solution in dropping is measured by
using a viscometer and an aspirator. The time in seconds taken by
the solvent in dropping is also measured by the same method as
described above, and the R.V. value and the I.V. value are
calculated according to the following equations: R.V.=Time in
seconds taken by the sample in dropping/Time in seconds taken by
the solvent in dropping I.V.=1/4.times.[(R.V.-1)/C]+3/4.times.(In
R.V./C)
[0035] In the above equation, C represents the concentration (g/100
ml) of the sample in the solution.
[0036] 2) Measurement of Modulus, Strength and Elongation of
Multifilament
[0037] The original yarn is left to stand under standard
conditions, that is, in a constant temperature and constant
humidity chamber at a temperature of 25.degree. C. and at a
relative humidity of 65% for 24 hours, and then a sample is
subjected to the measurement according to the method of ASTM 2256
using a tensile test machine. The properties of the multifilament
are measured by using an average of 8 values, excepting one minimum
value and one maximum value, from 10 values obtained from
measurement of 10 multifilaments. The initial modulus indicates the
gradient of the stress-strain curve before the yield point.
[0038] 3) Tenacity (g/d), Elongation at Specific Load (%) and
Modulus (g/d) of Monofilament
[0039] Ten monofilaments are extracted from an original yarn
(multifilament) which has been left to stand at a temperature of
25.degree. C. and at a relative humidity of 65 RH % for 24 hours.
Subsequently, a load (weak, monodenier.times.60 (mg)) defined
according to the denier number was applied to a sample having a
length of 20 mm by using a monofilament tensile test machine
Vibrojet 2000 manufactured by Lenzing Gruppe, and then the initial
load was measured at a tensile rate of 20 mm/min. The properties of
the monofilament are measured by using an average of 8 values,
excepting one minimum value and one maximum value, from 10 measured
values. The initial modulus indicates the gradient of the
stress-strain curve before the yield point.
[0040] 4) External Appearance
[0041] The original yarn which is wound on a winder in a cake form
is observed with naked eyes for 5 minutes using a Stroboscope, for
the presence or absence of fluff.
[0042] 5) Number of Fluff
[0043] The original yarn is measured along a length of 30,000 m by
using a Pilot Warper testing machine at a yarn speed of 300 to 500
m/min and at a sensitivity of 2.5 to 4.5 levels (relative
value).
[0044] 6) Proccessability
[0045] The frequency of yarn break occurring only on the godet
rollers is determined by observing the original yarn at a single
position for 24 hours.
[0046] 7) Area of Contact between Yarn and Godet Roller Surface
[0047] The yarn width at the first turning point is determined by
photographic measurement, and the yarn width at the final turning
point is determined in the same manner, thus to obtain an average
of the two values. The contact area is calculated by the equation:
Contact area=average yarn width.times.number of turns.times.radius
of godet roller.times.2 (for a pair of godet rollers)
EXAMPLES
Examples 1 to 3
[0048] A polyester chip having an intrinsic viscosity of 1.00 was
melted, and the melt polymer was extruded through a nozzle having
192 orifices, each orifice having a diameter of 0.6 mm and a ratio
of length and diameter (L/D) of 3. The extruded polymer was
quenched with air at 15.degree. C., gathered and oiled.
Subsequently, the filament was subjected to winding 5 turns at the
second godet rollers (primary drawing point) at 100.degree. C., and
7 turns at the third godet rollers (secondary drawing point) at
125.degree. C., with the ratio of the primary draw at the second
godet rollers and the third godet rollers to the secondary draw at
the third godet rollers and the fourth godet rollers being 75%:25%.
A guide in a flat form having a 4 mm-wide groove was applied before
the second godet rollers and the third godet rollers. The speed of
the fourth godet rollers was set at 2700 m/min. Thus, filaments of
1500 denier each were spun and drawn under the spinning conditions
presented in Table 1. The results are given in Table 5.
Comparative Example 1
[0049] A filament was produced in the same manner as in Examples 1
to 3 described above, except that a guide in a flat form having a
6.5 mm-wide groove was applied before the second and third godet
rollers, and the filament was subjected to winding 5 turns at the
second godet rollers and 7 turns at the third godet rollers.
Comparative Example 2
[0050] A filament was produced in the same manner as in Comparative
Example 1, except that a guide in a flat form having a narrow
V-shaped groove (width of the guide groove being 2.5 mm) was
applied before the second and third godet rollers, and the filament
was subjected to winding 6 turns 5 at the second godet rollers and
8 turns at the third godet rollers. TABLE-US-00001 TABLE 1 Example
Example Example Comp. Comp. Condition 1 2 3 Ex. 1 Ex. 2 Temperature
295 297 300 285 310 of melt polymer (.degree. C.) Temperature 300
305 310 285 315 of polymer in gear pump (.degree. C.) Length of 320
380 440 250 550 hood heater (mm) Temperature 350 375 400 320 410 of
hood heater (.degree. C.) Pressure of 90/100 110/120 110/120 50/60
130/140 quenching air (mmAq) Area of 6500 6000 5500 11000 3500
contact with 2.sup.nd GR (mm.sup.2) Area of 15500 14500 13500 20000
12000 contact with 3.sup.rd GR (mm.sup.2) Total 6.4 6.5 6.55 6.0
6.3 draw ratio Denier 1510 1508 1518 1509 1516
Examples 4 to 6
[0051] A polyester chip having an intrinsic viscosity of 1.05 was
melted, and the melt polymer was extruded through a nozzle having
192 orifices, each orifice having a diameter of 0.6 mm and a ratio
of length and diameter (L/D) of 3. The extruded polymer was
quenched with air at 15.degree. C., gathered and oiled.
Subsequently, the filament was subjected to winding 6 turns at the
second godet rollers (primary drawing point) at 100.degree. C., and
7 turns at the third godet rollers (secondary drawing point) at
125.degree. C., with the ratio of the primary draw at the second
godet rollers and the third godet rollers to the secondary draw at
the third godet rollers and the fourth godet rollers being 73%:27%.
A guide in a flat form having a 4 mm-wide groove was applied before
the second godet rollers and the third godet rollers. The speed of
the fourth godet rollers was set at 2700 m/min. Thus, filaments of
1500 denier each were spun and drawn under the spinning conditions
presented in Table 2. The results are given in Table 5.
Comparative Example 3
[0052] A filament was produced in the same manner as in Examples 4
to 6 described above, except that a guide in a flat form having a
6.5 mm-wide groove was applied before the second and third godet
rollers, and the filament was subjected to winding 5 turns at the
second godet rollers and 7 turns at the third godet rollers.
Comparative Example 4
[0053] A filament was produced in the same manner as in Comparative
Example 3, except that a guide having a narrow V-shaped groove
(width of the guide groove being 2.5 mm) was applied before the
second and third godet rollers, and the filament was subjected to
winding 6 turns at the second godet rollers and 8 turns at the
third godet rollers. TABLE-US-00002 TABLE 2 Example Example Example
Comp. Comp. Condition 4 5 6 Ex. 3 Ex. 4 Temperature 298 300 302 299
320 of melt polymer (.degree. C.) Temperature 305 308 310 300 315
of polymer in gear pump (.degree. C.) Length of 320 380 440 250 550
hood heater (mm) Temperature 350 375 400 320 440 of hood heater
(.degree. C.) Pressure of 90/100 110/120 110/120 40/50 130/140
quenching air (mmAq) Area of 7000 6500 6000 11500 3800 contact with
2.sup.nd GR (mm.sup.2) Area of 16000 15000 14000 21000 12500
contact with 3.sup.rd GR (mm.sup.2) Total 6.3 6.4 6.5 5.9 6.2 draw
ratio Denier 1520 1514 1525 1511 1517
Examples 7 to 9
[0054] A polyester chip having an intrinsic viscosity of 1.00 was
melted, and the melt polymer was extruded through a nozzle having
192 orifices, each orifice having a diameter of 0.6 mm and a ratio
of length and diameter (L/D) of 3. The extruded polymer was
quenched with air at 15.degree. C., gathered and oiled.
Subsequently, the filament was subjected to winding 5 turns at the
second godet rollers (primary drawing point) at 100.degree. C., and
8 turns at a third godet rollers (secondary drawing point) at
125.degree. C., with the ratio of the primary draw at the second
godet rollers and the third godet rollers to the secondary draw at
the third godet rollers and the fourth godet rollers being 75%:25%.
A guide in a flat form having a 4 mm-wide groove was applied before
the second godet rollers and the third godet rollers. The speed of
the fourth godet rollers was set at 3000 m/min. Thus, filaments of
1000 denier each were spun and drawn under the spinning conditions
presented in Table 3. The results are given in Table 5.
Comparative Example 5
[0055] A filament was produced in the same manner as in Examples 7
to 9 described above, except that a guide in a flat form having a
6.5 mm-wide groove was applied before the second and third godet
rollers, and the filament was subjected to winding 5 turns at the
second godet rollers and 8 turns at the third godet rollers.
Comparative Example 6
[0056] A filament was produced in the same manner as in Comparative
Example 5, except that a guide having a narrow V-shaped groove
(width of the guide groove being 2.5 mm) was applied before the
second and third godet rollers, and the filament was subjected to
winding 7 turns at the second godet rollers and 9 turns at the
third godet rollers. TABLE-US-00003 TABLE 3 Example Example Example
Comp. Comp. Condition 7 8 9 Ex. 5 Ex. 6 Temperature 295 297 300 285
310 of melt polymer (.degree. C.) Temperature 300 305 310 285 315
of polymer in gear pump (.degree. C.) Length of 320 380 400 250 550
hood heater (mm) Temperature 350 375 400 320 440 of hood heater
(.degree. C.) Pressure of 90/100 110/120 110/120 40/50 130/140
quenching air (mmAq) Area of 6700 6200 5700 11000 3200 contact with
2.sup.nd GR (mm.sup.2) Area of 15500 14500 13500 20500 12000
contact with 3.sup.rd GR (mm.sup.2) Total 6.40 6.44 6.48 6.00 6.30
draw ratio Denier 1010 1004 1018 1013 1016
Examples 10 to 12
[0057] A polyester chip having an intrinsic viscosity of 1.05 was
melted, and the melt polymer was extruded through a nozzle having
192 orifices, each orifice having a diameter of 0.6 mm and a ratio
of length and diameter (L/D) of 3. The extruded polymer was
quenched with air at 15.degree. C., gathered and oiled.
Subsequently, the filament was subjected to winding 5 turns at the
second godet rollers (primary drawing point) at 100.degree. C., and
8 turns at the third godet rollers (secondary drawing point) at
125.degree. C., with the ratio of the primary draw at the second
godet rollers and the third godet rollers to the secondary draw at
the third godet rollers and the fourth godet rollers being 70%:30%.
A guide in a flat form having a 4 mm-wide groove was applied before
the second godet rollers and the third godet rollers. The speed of
the fourth godet rollers was set at 3000 m/min. Thus, filaments of
1000 denier each were spun and drawn under the spinning conditions
presented in Table 4. The results are given in Table 5.
Comparative Example 7
[0058] A filament was produced in the same manner as in Examples 10
to 11 described above, except that a guide in a wide flat form
having a 6.5 mm-wide groove was applied before the second and third
godet rollers, and the filament was subjected to winding 5 turns at
the second godet rollers and 8 turns at the third godet
rollers.
Comparative Example 8
[0059] A filament was produced in the same manner as in Comparative
Example 7, except that a guide having a narrow V-shaped groove
(width of the guide groove being 2.5 mm) was applied before the
second and third godet rollers, and the filament was subjected to
winding 4 turns at the second godet rollers and 9 turns at the
third godet rollers. TABLE-US-00004 TABLE 4 Example Example Exam-
Comp. Comp. Condition 10 11 ple 12 Ex. 7 Ex. 8 Temperature 296 297
298 299 320 of melt polymer (.degree. C.) Temperature 310 310 310
300 315 of polymer in gear pump (.degree. C.) Length of 320 380 400
250 550 hood heater (mm) Temperature 350 375 400 320 440 of hood
heater (.degree. C.) Pressure of 90/100 110/120 110/120 40/50
130/140 quenching air (mmAq) Area of 7000 6500 5900 11500 3600
contact with 2.sup.nd GR (mm.sup.2) Area of 16000 15000 14000 21000
12500 contact with 3.sup.rd GR (mm.sup.2) Total 6.30 6.35 6.4 5.85
6.15 draw ratio Denier 1010 1004 1018 1013 1016
[0060] TABLE-US-00005 TABLE 5 Drawn Yarn Monofilament
Processability Elongation Elongation Appearance Number of (yarn
under under (presence fluffs breaking stress of stress of or
absence (entities/ entities/ Elongation Elongation 2.0 g/d to 10.0
g/d to of fluff or 30,000 Day .times. Tenacity at break at 2.0 g/d
9.0 g/d break point loop) meter) position) (g/d) (%) (%) (%) (%)
Ex. 1 0 0 0.5 11.16 12.8 2.0 6.7 2.6 Ex. 2 0 0 1.2 11.55 12.1 1.9
6.5 2.7 Ex. 3 0 0 1.3 11.90 11.7 1.9 6.0 3.1 Ex. 4 0 0 0.9 11.33
12.3 1.7 6.6 2.4 Ex. 5 0 1 1.5 11.68 11.6 1.8 6.1 2.8 Ex. 6 0 1 1.6
12.08 11.1 1.7 5.8 2.9 Ex. 7 0 0 0.5 11.78 13.2 2.1 5.9 4.0 Ex. 8 0
0 0.8 11.90 12.6 1.8 5.7 4.4 Ex. 9 0 0 0.9 12.33 11.9 1.7 5.7 4.4
Ex. 10 0 0 0.9 11.69 13.1 2.0 5.9 4.3 Ex. 11 0 0 1.3 11.98 12.3 1.8
5.6 4.7 Ex. 12 0 1 1.5 12.45 11.9 1.7 5.6 4.4 Comp. 6 20 or more
3.5 10.17 17.0 2.8 10.3 0.5 Ex. 1 Comp. 4 7 2.8 10.90 15.2 2.6 7.9
1.1 Ex. 2 Comp. 20 or more 20 or more 3.2 10.22 16.4 2.5 8.8 0.5
Ex. 3 Comp. 9 11 2.7 10.89 15.6 2.4 7.9 1.0 Ex. 4 Comp. 3 9 3.7
9.82 17.1 2.7 10.8 0 Ex. 5 Comp. 2 5 3.2 10.33 15.8 2.4 8.2 0.9 Ex.
6 Comp. 5 20 or more 4.3 9.98 17.0 2.5 10.4 0 Ex. 7 Comp. 2 6 3.1
10.43 15.9 2.3 7.8 1.2 Ex. 8
[0061] The present invention is effective in maintaining the
intrinsic properties of polyethylene terephthalate chip as much as
possible, and in allowing excellent spinnability by optimizing the
spinning conditions, thus suppressing generation of fluffs. The
invention can provide an industrial high tenacity polyethylene
terephthalate yarn having high modulus, high tenacity and low
elongation at break due to high ratio drawing, which is useful for
industrial rope, reinforcement material for construction, webbing,
seatbelt and the like.
* * * * *