WO2005054552A1

WO2005054552A1 - Chemical yarn manufacturing apparatus, and cooling filter, nozzle and quenching air isolation unit provided therein

Info

Publication number: WO2005054552A1
Application number: PCT/KR2004/000057
Authority: WO
Inventors: Young-Ho Choi
Original assignee: Young-Ho Choi
Priority date: 2003-12-04
Filing date: 2004-01-14
Publication date: 2005-06-16

Abstract

A chemical yarn manufacturing apparatus capable of making a filament with improved properties such as circularity, elastic recovery and strength, as well as a cooling filter, a nozzle and a quenching air isolation unit provided in the apparatus is disclosed. The chemical yarn manufacturing apparatus may produce such an improved filament by optimizing, a velocity profile of a cooling air emitted from a cooling filter. In addition, the apparatus may minimize die swelling of a filament ejected through the nozzle and improve circularity of the manufactured filament. Moreover, the apparatus isolates the cooling air from being dispersed to the nozzle in order to prevent temperature decrease of the polymer melt in the nozzle.

Description

CHEMICAL YARN MANUFACTURING APPARATUS, AND COOLING FILTER, NOZZLE AND QUENCHING AIR ISOLATION UNIT PROVIDED THEREIN

TECHNICAL FIELD The present invention relates to a chemical yarn manufacturing apparatus as well as a cooling filter, a nozzle and a quenching air isolation unit provided in the apparatus, and more particularly to a chemical yarn manufacturing apparatus capable of

manufacturing a filament with improved properties such as circularity, elastic recovery

and strength as well as a cooling filter, a nozzle and a quenching air isolation unit provided in the apparatus.

BACKGROUND ART Generally, a chemical yarn manufacturing procedure includes spinning a polymer melt through a nozzle, solidifying the spun polymer, or a filament, by supply of a quenching air and then focusing it, and then taking up it around a bobbin. The nozzle is installed in the lower surface of a spinning pack so as to spin a

polymer melt, which passed through a distributor, through a nozzle hole. Die swelling occurs at the polymer melt passing through the nozzle hole. This die swelling is a phenomenon that the polymer melt passing through the nozzle hole is expanded due to difference between the high pressure in the nozzle and the atmosphere pressure out of

the nozzle. The die swelling gives an influence on circularity of the manufactured filament, and circularity is generally improved as the die swelling is less. Thus, it is required to minimize the die swelling in order to improve quality of the manufactured

filament. In addition, the die swelling tends to be decreased as a pressure loss occurring

while the polymer melt passes through the nozzle hole is greater. The pressure loss is

caused by friction between the polymer melt and the inner surface of the nozzle hole.

Thus, as the length of the nozzle hole is long in comparison to the diameter of the

nozzle hole, the die swelling is reduced. However, if the length of the nozzle hole is

too long in comparison to the diameter, the pressure loss is so big to make a spinning

speed slow. The nozzle holes that spin filaments are distributed at predetermined intervals

over the entire lower surface of the nozzle. Thus, the time for the polymer melt

discharged through each nozzle hole to stay in the nozzle is different from each other.

It is because a polymer melt spun through a nozzle hole near the path of the distributor

stays in the nozzle for a short time, while a polymer melt spun through a nozzle hole

distant from the path stays in the nozzle for a long time. In addition, it is also problem

that pressure applied to each nozzle hole is also diversified. It is because the flow rate

of the polymer melt in a nozzle hole near the path is not equal to that in a nozzle hole

distant from the path, and furthermore a friction is applied between the polymer melt

and the inner surface of the nozzle. Due to such problems, filaments manufactured

through each nozzle hole show different properties such as strength depending on the location of the nozzle hole.

Meanwhile, the cooling process for cooling a filament by supplying a quenching

air thereto also gives a significant influence on circularity, elastic recovery and strength of the filament. That is to say, it seriously affects speed and amount of the quenching

air ejected.

In order to supply the quenching air, there are used cross pass air dispersion and

central air dispersion. The cross flow air dispersion is a method for cooling filaments by ejecting a

quenching air from a lateral position out of the spun filament. However, the cross flow

air dispersion has a problem that a filament near each air supply means is rapidly cooled

while a filament distant therefrom is cooled relatively late. In order to solve this

problem, the central air dispersion is proposed. The central air dispersion is a method for cooling filaments by installing cooling

filters in a lower portion of the nozzle center and then ejecting the quenching air toward

the filaments around it. The central air dispersion is disclosed in Korean Patent Filing

No. 10-1999-0016987. The cooling filter ejects a quenching air at a constant speed

regardless of the position of the cooling filter. In order to manufacture filaments with improved properties using the central air dispersion, the filaments should be rapidly cooled. However, if the quenching air is

excessively ejected at a constant rate or the quenching air is ejected too rapid for rapid

cooling of the filament regardless of positions of cooling filters, filaments are collided

with and adhered to each other, and fine dust is generated around the filaments. Thus,

it is required to optimize an amount of ejected quenching air and an ejection velocity

profile of the quenching air depending on the position of the cooling filters. In

addition, it is required to select a structure of the cooling filter so as to be capable of

ejecting a quenching air with an optimized amount and a velocity profile of the quenching air.

The quenching air ejected from the cooling filter has a temperature of about 15

to 200°C, which is lower than a temperature of the polymer melt, 200 to 400°C. For

such reason, if the quenching air is contacted with the lower portion of the spinning

pack, a temperature of the lower portion of the spinning pack is lowered. If the

temperature of the lower portion of the spinning pack is lowered, properties of the

polymer melt are changed, not to give desired quality of filament.

In addition, if the distance between the surface of the cooling filter and a

discharge hole nearest to the surface of the cooling filter is too short, the filament may

be adhered to the surface of the cooling filter. If the distance is too long, effective

cooling is not provided to the filament. Thus, it is required to optimize the distance

between the surface of the cooling filter and the discharge hole nearest to the surface of

the cooling filter.

DISCLOSURE OF INVENTION

The present invention is designed to solve the problems of the prior art, and

therefore an object of the invention is to provide a chemical yarn manufacturing apparatus capable of manufacturing a filament with improved properties by optimizing

an amount and a velocity profile of a quenching air, and a cooling filter provided

therein.

Another object of the present invention is to provide a chemical yarn

manufacturing apparatus capable of minimizing die swelling and improving circularity

of a manufactured filament, and a nozzle provided therein. Still another object of the present invention is to provide a chemical yarn

manufacturing apparatus capable of isolating a quenching air from being dispersed to

the nozzle and selectively heating an air adjacent to the nozzle, and a quenching air

isolation unit provided therein. In order to accomplish the above object, the present invention provides a

chemical yarn manufacturing apparatus, which includes a cooling filter having a cooling

region where a quenching air is ejected, wherein a lower portion of the cooling region

has a thicker section than an upper portion thereof.

Preferably, the chemical yarn manufacturing apparatus further includes a nozzle

that is provided with: a downward inclined surface formed at a predetermined angle

from a center of an upper surface of the nozzle to a position adjacent to a side of the

nozzle; a discharge hole vertically formed from the position adjacent to the side to a

position adjacent to a lower surface of the nozzle; and a nozzle hole communicated with

an end of the discharge hole to be capable of spinning a polymer melt, wherein the

nozzle satisfies the following formula:

2.5 ≤ S/G < 3.5 (0.1 mm < G < 0.18 mm) where S is a length of the nozzle hole, and G is a diameter of the nozzle hole.

Here, the chemical yarn manufacturing apparatus preferably further includes a

quenching air isolation unit installed to a predetermined position adjacent to the nozzle

that spins a filament so as to isolate a quenching air ejected from the cooling filter from

being dispersed to the nozzle.

In addition, the chemical yarn manufacturing apparatus preferably further

includes a quenching air supply means including a cap member installed to a lower portion of the cooling filter and communicated with the cooling filter, and an arm

communicated with the cap member to supply a quenching air; a ring installed between

the cooling filter and the cap member to minimize contacts between a filament and the

cooling filter and between the filament and the cap member, the ring having a

perforation of a predetermined size therein so that the quenching air is passed through;

and a filament guide means installed to a portion of the arm where the filament passes

so as to minimize contact between the filament and the arm.

In another aspect of the invention, there is provided a cooling filter, which

includes a cooling region where a quenching air is ejected to cool a filament spun from a

nozzle, wherein a lower portion of the cooling region has a thicker section than an upper

portion thereof.

Preferably, the cooling filter is configured so that a lower end of the cooling

region has a thicker section than an upper end thereof, and a sectional thickness of the

cooling region is linearly changed between the upper end and the lower end. More preferably, the sectional thickness of the upper and lower ends of the cooling region satisfies the following formula: l ≤ Tι/T₂ ≤ 1.2 where Ti is a sectional thickness of the lower end of the cooling region where

the quenching air is ejected from the cooling filter, and T₂ is a sectional thickness of the

upper end of the cooling region where the quenching air is ejected from the cooling

filter.

Here, a diameter of a micro pore of the cooling filter where the quenching air is

ejected, and a length of the cooling region preferably satisfy the following formula: 30 μm < D < 45 μm

220 mm < H where D is the diameter of the micro pore where the quenching air is ejected,

and H is the length of the cooling region where the quenching air is ejected. In still another aspect of the invention, there is also provided a nozzle, which

includes: a downward inclined surface formed at a predetermined angle from a center of

an upper surface of the nozzle to a position adjacent to a side of the nozzle; a discharge

hole vertically formed from the position adjacent to the side to a position adjacent to a

lower surface of the nozzle; and a nozzle hole communicated with an end of the

discharge hole to be capable of spinning a polymer melt, wherein the nozzle satisfies the following formula:

2.5 < S/G < 3.5 (0.1 mm < G < 0.18 mm) where S is a length of the nozzle hole, and G is a diameter of the nozzle hole.

Preferably, the discharge hole satisfies the following formula: 2 mm ≤ K < 10 mm (60 mm < W < 300 mm) where K is a distance between a surface of a cooling filter and a discharge hole

nearest to the surface of the cooling filter, and W is a diameter of the nozzle.

Here, the discharge hole preferably satisfies the following formula:

J < 6 mm wherein J is a distance between a discharge hole nearest to the center and a

discharge hole farthest from the center.

In further another aspect of the invention, there is also provided a quenching air

isolation unit, installed to a predetermined position adjacent to a nozzle that spins a polymer melt so as to isolate a quenching air ejected from a cooling filter from being dispersed to the nozzle, wherein the quenching air isolation unit includes a plate having

a first perforation of a predetermined size so that a filament spun from the nozzle passes through the first perforation and the cooling filter is selectively inserted into the first perforation. Preferably, the quenching air isolation unit further includes a sub plate installed

to the plate, wherein the sub plate has a second perforation corresponding to the first perforation so that the filament passes through the second perforation and the cooling filter is selectively inserted into the second perforation. More preferably, the sub plate includes a heating means for selectively heating air between the nozzle and the sub plate.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of preferred embodiments of the present invention will be more fully described in the following detailed description, taken accompanying drawings. In the drawings: FIG. 1 is a side view showing a chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention;

FIG. 2 is a sectional view showing a cooling filter provided in the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention; FIG. 3 is a sectional view partially showing a micro pore of a cooling filter in FIG. 2;

FIG. 4 is a side sectional view showing a cooling filter and a quenching air supply unit in the chemical yarn manufacturing apparatus according to a preferred

embodiment of the present invention; FIG. 5 is a perspective view showing a filament guide in the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention; FIG. 6 is a perspective view showing a ring in the chemical yarn manufacturing

apparatus according to a preferred embodiment of the present invention; FIG. 7 is a plane view showing a quenching air isolation unit provided in the chemical yarn manufacturing apparatus according to a preferred embodiment of the

present invention; FIG. 8 is a sectional view taken along A-A line of FIG. 7; FIG. 9 is a plane view showing a plate of the quenching air isolation unit of FIG.

7; FIG. 10 is a plane view showing a sub plate of the quenching air isolation unit of FIG. 7; FIG. 11 is a front view showing the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention; FIG. 12 is a plane view showing a nozzle provided in the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention;

FIG. 13 is a sectional view taken along B-B line of FIG. 12; FIG. 14 shows a filament spun from the nozzle of the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention; FIG. 15 is an expanded sectional view taken along C-C line of FIG. 13; and FIG. 16 shows a filament spun from the nozzle of the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention.

BEST MODES FOR CARRYING OUT THE INVENTION

Hereinafter, preferred embodiments of the present invention will be described in

detail referring to the accompanying drawings. Prior to the description, it should be

understood that the terms used in the specification and appended claims should not be

construed as limited to general and dictionary meanings, but interpreted based on the

meanings and concepts corresponding to technical aspects of the present invention on

the basis of the principle that the inventor is allowed to define terms appropriately for

the best explanation. Therefore, the description proposed herein is just a preferable

example for the purpose of illustrations only, not intended to limit the scope of the

invention, so it should be understood that other equivalents and modifications could be

made thereto without departing from the spirit and scope of the invention.

FIG. 1 is a side view showing a chemical yarn manufacturing apparatus

according to a preferred embodiment of the present invention, FIG. 2 is a sectional view

showing a cooling filter provided in the chemical yarn manufacturing apparatus, and

FIG. 3 is a sectional view partially showing a micro pore of the cooling filter of FIG. 2.

In addition, FIG. 4 is a side sectional view showing the cooling filter and a quenching

air supply unit of the chemical yarn manufacturing apparatus. Referring to FIGs. 1 to 4, the cooling filter 10 is installed to a lower portion of a

nozzle 72 so as to eject a quenching air to a filament 88 spun from the nozzle 72.

The cooling filter 10 has a hollow inside so that the quenching air may pass

through it. The lower portion of the cooling filter 10 is connected to a cap member 22, described later, so that the quenching air is supplied into the cooling filter 10. In

addition, an insulation member 11 for isolating heat of the nozzle 72 is installed to an

upper portion of the cooling filter 10. The cooling filter 10 is made using filter fabric,

reinforced filter fabric, or sintered alloy of such as copper. In a sidewall of the cooling filter 10, micro pores 12 are formed in a radial

direction so that the air in the cooling filter 10 is ejected out through the micro pores 12,

thereby giving a cooling function. In FIG. 2, a region where the quenching air is

ejected is denoted as a cooling region H.

In order to produce a filament with improved properties, the spun filament

should be cooled rapidly. If a quenching air is excessively ejected at a constant rate

regardless of position of the cooling filter for the sake of rapid cooling of the filament,

filaments are collided with and adhered to each other, and fine dust is generated around

the filaments.

Thus, it is preferred that an ejection rate of the quenching air is rapid in the

upper portion of the cooling filter 10 and slow in the lower portion thereof rather than in

the upper portion.

In order that the ejection rate of the quenching air is more rapid in the upper

portion of the cooling filter 10 than in the lower portion thereof, a sectional thickness of

the upper portion of the cooling region H should be smaller than that of the lower

portion. In addition, a sectional thickness between the upper end 13a of the cooling

region H and the lower end 13b thereof should be linearly changed. That is to say, the

lower end 13b has a thicker section than the upper end 13a, and a sectional thickness

between the lower end 13b and the upper end 13a becomes gradually smaller from the lower end 13b to the upper end 13a.

Preferably, an ejection rate at the upper end 13a of the cooling region H is faster

that that at the lower end 13b by 20% or less. In FIG. 3, V designates an ejection rate

of the quenching air ejected through the micro pore 12. If the ejection rate V₂ of the quenching air at the upper end 13a is faster than the

ejection rate V] of the quenching air at the lower end 13b by more than 20%),

excessively rapid cooling may deteriorate circularity of the filament 88. That is to say,

it is preferred to satisfy the following formula 1.

Formula 1

0 < (V2 - Vι)/Vι ≤ 0.2

In the formula 1, Ni is an ejection rate of the quenching air at the lower end 13b

of the cooling region H, and V₂ is an ejection rate of the quenching air at the upper end 13a of the cooling region H.

In order to satisfy the formula 1, the sectional thickness of the lower end 13b of

the cooling region H and the sectional thickness of the upper end 13a should satisfy the following formula 2.

Formula 2

1 < (T,)/(T₂) < 1.2

In the formula 2, Ti is the sectional thickness of the lower end 13b of the cooling region H where the quenching air is ejected, and T₂ is the sectional thickness of the

upper end 13a of the cooling region H where the quenching air is ejected.

The formula 2 is calculated using Moody Chart of hydro mechanism. It is also

calculated on the assumption that an ejection rate of the quenching air is 0.36 m/s at the

lower end 13b and a diameter D of the micro pore 12 where the quenching air is ejected

is 37.5 μm. In addition, it is assumed that a head loss of the micro pore 12 is identical

at both the lower end 13b and the upper end 13a, and it is assumed that an entrance

pressure drop is 0.

In addition, the diameter D of the micro pore 12 preferably satisfies the following formula 3.

Formula 3

30 μm < D < 45 μm

In the formula 3, D is a diameter of the micro pore 12.

If the diameter of the micro pore 12 exceeds 45 μm, the ejected quenching air

causes generation of fine dust in the air. On the while, if the diameter of the micro

pore 12 is less than 30 μm, it is not effective for cooling.

In addition, the length of the cooling region H preferably satisfies the following

formula 4.

Formula 4

220 mm < H In the formula 4, H is a length of the region where the quenching air is ejected

from the cooling filter 10.

If the length of the cooling region H is less than 220 mm, it is insufficient for

cooling of the filament. The cooling filter 10 whose cooling region H has a length

more than 220 mm may be applied to manufacturing of medical yarns as well as

industrial yarns.

The insulation member 11 isolates heat of a spinning pack 70 or a nozzle 72

from being transferred toward the cooling filter 10. The insulation member 11 is

Hemit made of ceramic, and its length is preferably 10 to 80 mm. A protrusion 15 is

formed on the upper portion of the insulation member 11 so that the protrusion 15 is

inserted and fixed in a groove (not shown) formed on the lower surface of the nozzle 72.

It helps the cooling filter 10 to be accurately positioned at the center of the lower surface of the nozzle 72. The chemical yarn manufacturing apparatus 900 includes a quenching air supply

unit. The quenching air supply unit 20 includes a cap member 22 installed to a lower

portion of the cooling filter 10, an arm 30 communicated with the cap member 22 to

supply a quenching air, and a carrier 26.

The carrier 26 moves the cap member 22 and the arm 30 so that the cooling filter

10 is positioned at a lower center of the nozzle 72.

The carrier 26 includes a vertical carrying unit 26a for enabling vertical

movement, and a horizontal carrying unit 26b for enabling horizontal movement. The

vertical and horizontal carrying units 26a and 26b are respectively provided with a piston and a cylinder, respectively operated by hydraulic or pneumatic pressure. The

carrier 26 may be controlled in connection to a control member (not shown).

The cap member 22 is installed to the lower portion of the cooling filter 10 and

supplies a quenching air from the arm 30 to the cooling filter 10. The cap member 22

has a hollow 22a formed therein in a length direction. The hollow 22a is

communicated with the arm 30 and receives a quenching air.

The upper portion of the cap member 22 is formed in correspondence to the

inner diameter of the cooling filter 10 so that the cap member 22 may be inserted and

installed in the cooling filter 10. The cap member 22 is installed to the cooling filter

10 by use of a bolt member 24, as shown in FIG. 4. The bolt member 24 is inserted

into the cap member 22 from a lower position, and then combined to the insulation

member 11.

The arm 30 is communicated with the hollow 22a of the cap member 22 and

supplies a quenching air from a quenching air supply pipe 30a to the cap member 22.

To the quenching air supply pipe 30a connected to the arm 30, a quenching air control

valve 30b is installed to control a volume of the quenching air.

Preferably, filament guides 34 are installed to the upper and lower ends of the

arm 30 so as to minimize contacts between the arm 30 and the spun filament 88. That

is to say, the filament guides 34 are installed at places where the filament passes,

thereby minimizing contacts between the spun filament 88 and the arm 30. As shown

in FIGs. 4 and 5, a hole 34a is formed in the filament guide 34, and a protrusion 31 of

the arm 30 is inserted into the hole 34a so that the filament guide 34 is installed thereto.

In addition, a ring 32 may be installed between the cooling filter 10 and the cap member 22 so as to minimize frictional resistance and contacts between the filament 88

and the cooling filter 10 and between the filament 88 and the cap member 22. A

perforation 32a of a predetermined size is formed in the ring 32 as shown in FIG. 6 so

that a quenching air may pass through it. The filament guide 34 and the ring 32 are made of ceramic material that is

capable of minimizing resistance caused by friction and contact. Preferably, the

filament guide 34 and the ring 32 are prepared to have a surface roughness of 0.8 to 3.0

μm.

Preferably, the chemical yarn manufacturing apparatus 900 further includes a

quenching air isolation unit 400 that isolates a quenching air ejected from the cooling

filter 10 from being contacted with the nozzle 72.

The quenching air isolation unit 400 is installed to a position adjacent to the

nozzle 72. The quenching air isolation unit 400 includes a plate 40 for isolating an

quenching air, and a sub plate 50 selectively installed to the plate 40, as shown in FIG.

7.

The plate 40 has a first perforation 42 formed with a predetermined size. The

first perforation 42 allows the filament 88 spun from the nozzle 72 and the insulation member 11 of the cooling filter 10 to pass through it.

The plate 40 is preferably installed at the same height as the lower surface 1 la of

the insulation member 11 or above the upper end 13a of the cooling region where the

quenching air is ejected.

Meanwhile, the sub plate 50 includes a second perforation 52 formed at a

position corresponding to the first perforation 42. That is to say, if the sub plate 50 is installed to the plate 40, the second perforation 52 is overlapped with the first

perforation 42 so that the insulation member 11 of the cooling filter 10 and the spun

filament 88 may pass through them. Preferably, the sub plate 50 is slid on the plate 40 for installation. For this

reason, the plate 40 includes an upper plate 44a, a lower plate 44b opposite to the upper

plate 44a, and spacers 46 installed between the upper plate 44a and the lower plate 44b

to make the upper and lower plates 44a and 44b spaced apart by a predetermined

distance. The spacers 46 are installed at both sides of the plate 40, and the sub plate 50

is inserted between the spacers 46. Preferably, at an opposite side of an entrance 47 into which the sub plate 50 is

inserted, a stopper 48 is further installed. The stopper 48 makes the sub plate 50

stopped at a position where the second perforation 52 of the sub plate 50 is coincided

with the first perforation 42 of the plate 40. The first perforation 42 is also formed in

the upper and lower plates 44a and 44b, respectively. In addition, as an alternative of the sliding manner, the plate 40 and the sub plate

50 may be combined using screws or bolts.

The sub plate 50 preferably further includes a handle member 54 installed at one

side, as shown in FIG. 10. The handle member 54 plays a role of sliding and mounting

the sub plate 50 between the upper and lower plates 44a and 44b. The sub plate 50 may include a heater 56 for selectively heating the air between

the nozzle 72 and the sub plate 50. The heater 56 includes a heat wire 56a installed to

the sub plate 50, and a temperature sensor 56b for measuring temperature of the sub

plate 50. The heat wire 56a is installed to the sub plate 50 to play a role of heating the sub

plate 50 to a predetermined temperature. The temperature sensor 56b measures

temperature of the sub plate 50 and then transmits its value to a control member (not

shown). In addition to the temperature sensor 56b, it is preferred to additionally install

a temperature sensor (not shown) for measuring temperature of an air between the

nozzle 72 and the sub plate 50 and then transmitting its value to the control member (not

shown). That is to say, the temperature of the sub plate 50 or the temperature of the air

between the nozzle 72 and the sub plate 50 is measured, and then the temperature value

is transmitted to the control member so as to control a power source (not shown)

supplied to the heat wire 56a.

The temperature between the nozzle 72 and the sub plate 50 may differ

depending on the kind of chemical yarns to be manufactured, but preferably in the range

of 100 to 320 °C. If the temperature is too high, properties of the polymer melt may be

changed. If the temperature is too low, any problem may be caused in fluidity of the polymer melt.

The quenching air isolation unit 400 is preferably installed to the chemical yarn

manufacturing apparatus 900 to be slidable thereon. For this reason, the quenching air

isolation unit 400 further includes a guide member 58 installed to a frame 60 of the

chemical yarn manufacturing apparatus 900, as shown in FIG. 11. But, the guide

member 58 is not depicted in FIG. 1 so as to show the quenching air isolation unit 400. The guide member 58 includes a lower guide member 58a. In addition, the

guide member 58 may further include an upper guide member 58b spaced apart from the

lower guide member 58a by a predetermined distance. This predetermined distance gives a gap for the plate 40 to be slid and inserted. In order to install the quenching air isolation unit 400 to the chemical yarn

manufacturing apparatus 900, screw combination or bolt combination may be used

instead of sliding it to the guide member. Meanwhile, the quenching air isolation unit may include only the plate 40, but excluding the sub plate 50. That is to say, a quenching air isolation unit without the

sub plate 50 is installed to the chemical yarn manufacturing apparatus 900. Preferably, the quenching air isolation unit is installed to the guide member 58 to be slidable. In

addition, the plate 40 may further include a heater identical to the heater 56 of the sub plate 50. That is to say, the plate 40 is provided with a heater including a heat wire and a temperature sensor so as to selectively heat the air between the nozzle 72 and the plate

40. FIG. 12 is a plane view showing the nozzle provided in the chemical yarn manufacturing apparatus according to a preferred embodiment of the present invention, and FIG. 13 is a sectional view taken along B-B line of FIG. 12. The nozzle 72 includes a downward inclined surface 77 formed at a predetermined angle from a center 73 of the upper surface to a position 75 adjacent to the side, and a discharge hole 79 vertically formed from the position 75 adjacent to the side to a position adjacent to the lower surface. The downward inclined surface 77 is inclined at a predetermined angle θ so that

the polymer melt passing through a distributor (not shown) may smoothly flow toward

the discharge hole 79. Preferably, the predetermined angle θ satisfies the following

condition. Formula 5 5° < q < 15°

In the formula 5, q is an angle between the downward inclined surface 77 and a horizontal surface.

If q < 5°, the polymer melt flows too slow, so an inner pressure of the spinning

pack 70 is increased. On occasions, increase of the inner pressure of the spinning pack 70 makes the polymer melt leaked out of the spinning pack 70. In addition, if q > 15°, flow of the polymer melt becomes fast, but dead space is

increased in the nozzle 72. This dead space is an area where the polymer melt is not flowed but stagnated. Thus, increase of the dead space gives not so good influence on properties of the polymer.

As shown in FIGs. 12 and 13, the discharge holes 79 are arranged on circumferences of a plurality of concentric circles. As a distance J between a discharge hole 79a nearest to the center 73 and a discharge hole 79b farthest from the center 73 is increased, properties of the filaments discharged through the discharge holes 79a and

79b are more differed from each other. That is to say, since the polymer melt passing through the discharge hole 79a nearest to the center 73 and the polymer melt passing through the discharge hole 79b farthest from the center 73 show different stagnation times, the manufactured filaments give different properties. In addition, since different pressures are applied to each discharge hole 79a or 79b, a discharging amount through

each discharge hole 79a or 79b is also different from each other. Thus, as the distance J between the discharge hole 79a nearest to the center 73 and the discharge hole 79b

farthest from the center 73 is shorter, difference of properties of the manufactured

filaments is reduced.

Preferably, the distance J between the discharge hole 79a nearest to the center 73

and the discharge hole 79b farthest from the center 73 satisfies the following formula 6.

Formula 6

J < 6 mm (60 mm < W < 300 mm)

In the formula 6, W is a diameter of the nozzle 72.

The nozzle 72 has a diameter W of 60 mm to 300 mm, and it may be applied to

not only general medical yarns but also industrial synthetic yarns. That is to say, the

nozzle 72 may be used for improving circularity, strength and ductility of medical yarns

and industrial yarns. Meanwhile, FIG. 14 shows the nozzle 72 and the filament 88 spun from the

nozzle 72. A distance K from the discharge hole nearest to the surface of the cooling

filter 10 to the surface of the cooling filter 10 preferably satisfies the following formula

7.

Formula 7

2 mm < K < 10 mm

In the formula 7, K is the distance from the surface of the cooling filter 10 to the discharge hole nearest to the surface of the cooling filter 10.

If K is less than 2 mm, the cooling filter 10 and the filament 88 may be adhered

to each other. If K is greater than 10 mm, it is not effective in cooling the filament 88.

A nozzle hole 81 is formed at the end of the discharge hole 79, as shown in FIG.

15. The nozzle hole 81 plays a role of spinning the polymer melt introduced through

the discharge hole 79. A ratio (S/G) of a diameter G and a length S of the nozzle hole

81 has a relation to die swelling.

The die swelling is a phenomenon that the polymer passing through the nozzle

hole 81 is expanded due to difference between inner and outer pressures of the nozzle,

as shown in FIG. 16. As a diameter t of an expanded part 89 caused by the die

swelling is smaller, circularity of the manufactured filament is improved. A formula

required for calculation of the circularity is as follows.

Formula 8 Circularity (%>) = (diameter of minimal circumscribed circle - diameter of

maximum inscribed circle)/ {(diameter of minimal circumscribed circle + diameter of

maximum inscribed circle)/2} x 100

In the formula 8, the minimum circumscribed circle and the maximum inscribed

circle are circles tangent to the filament, respectively.

As the diameter t of the expanded part 89 is smaller, the point that the diameter F

of the spun filament is coincided with the diameter G of the nozzle hole 81 is departed

from the nozzle hole 81. That is to say, M in FIG. 16 becomes longer. In FIG. 16, M is a distance from the point that the diameter F of the spun filament is coincided with the

diameter G of the nozzle hole to the nozzle hole 81.

In order to improve properties of the filament by minimizing the die swelling,

the diameter G and the length S of the nozzle hole 81 preferably satisfy the following

formula 9.

Formula 9

2.5 < S/G < 3.5 (0.1 mm ≤ G < 0.18 mm)

In the formula 9, G is a diameter of the nozzle hole 81, and S is a length of the

nozzle hole 81.

The diameter G of the nozzle hole 81 is determined on the consideration of a

diameter of a filament to be made, a pressure loss generated when the polymer melt

passes through the nozzle hole 81 , and a factional coefficient between the inner surface

of the nozzle hole 81 and the polymer melt.

If the ratio of the diameter G and the length S of the nozzle hole 81, namely S/G,

is less than 2.5, the diameter t of the expanded part 89 becomes 5 times of the diameter

G of the nozzle hole 81 or more. In addition, if S/G is greater than 3.5, a pressure loss

of the polymer melt is increased too greatly, which gives an influence on the work.

That is to say, a spinning rate is too deteriorated.

In addition, it is known that circularity less than 1% is suitable for production of

filaments. If S/G is less than 2.5 or greater than 3.5, circularity becomes more than 1%,

which is not suitable for filament production. Now, a process of manufacturing a chemical yarn 90 with the use of the

chemical yarn manufacturing apparatus 900 according to a preferred embodiment of the

present invention is described.

First, a polymer melt moved to the spinning pack 70 is spun through the nozzle

72 installed in the lower surface of the spinning pack 70. The nozzle hole 81 of the

nozzle 72 preferably satisfies the formula 9. In addition, the discharge hole 79 of the

nozzle preferably satisfies the formulas 6 and 7.

The spun filament 88 is cooled by means of a quenching air ejected from the

cooling filter 10. The quenching air has a temperature of about 16 to 25°C and a

velocity of 0.05 to 0.7 m/s. In addition, for effective rapid cooling, a wind velocity at

the upper end 13a of the cooling region H and a wind velocity at the lower end 13b are

set to satisfy the formula 1. At this time, the quenching air isolation unit 400 isolates

the quenching air ejected from the cooling filter 10 from being contacted with the nozzle

72. In addition, the heater 56 installed to the sub plate 50 selectively heats the air

between the nozzle 72 and the sub plate 50.

The ring 32 installed between the cooling filter 10 and the cap member 22

minimizes contacts between the filament 88 and the cap member 22 and between the

filament 88 and the cooling filter 10. In addition, the filament guides 34, installed to

the upper and lower ends of a portion of the arm 30 where the filament 88 passes,

minimizes contacts between the filament 88 and the arm 30.

The filament 88 cooled by the quenching air is focused at about 70 cm below the

nozzle. Subsequently, oil jet guides 92a and 92b of an oil supply member 92 is used to

supply oil to a focused yarn 90, and the supplied oil is uniformly dispersed to the yarn with the use of a migration nozzle 94. This oil prevents static electricity and gives

evenness to the yarn 90 so that it may be easily handled in a stretching process.

Then, the yarn is taken up with the use of a take-up machine (not shown)

installed below the oil supply member 92.

Embodiment 1

A polyamide melt is spun through the nozzle 72, and then the spun polyamide

filament is cooled by supplying a quenching air thereto through the cooling filter 10.

At this time, the quenching air has a temperature of 20 °C, an average velocity of 0.36

m/s, and a pressure of 100 mmHg (gage pressure). The quenching air is ejected from

80 mm below the nozzle 72. The filament is focused at 70 cm below the nozzle 72,

and oil is supplied from the oil supply member 92 at 73 cm below the nozzle 72. A

spinning rate of the polyamide filament is 3500 m/min.

The following table 1 shows effects of the ratio Tι/T₂, influenced on circularity

and elastic recovery of the filament. The circularity is calculated using the formula 8,

after optionally selecting and measuring 10 points on a section of the spun filament.

The elastic recovery is calculated using the following formula 10.

Formula 10 Elastic Recovery (%) = ( Y_S)/(Y₀) x 100

In the formula 10, Y, is a length of the yarn when a load of 750 gf is exerted for

one hour within the elastic limit and then the load is removed, and Y₀ is a length of the original yarn.

Table 1

In the table 1, it would be understood that, if the ratio T)/T₂ is less than 1.0 or greater than 1.2, the circularity exceeds 1%> and the elastic recovery is more than 115%. It is because the filament is not effectively cooled in the cooling procedure.

Embodiment 2 The following table 2 shows an effect of the diameter D of the micro pore where the quenching air is ejected and the length H of the cooling region where the quenching air is ejected, influenced on circularity and elastic recovery. Experimental conditions other than D and H are identical to those of the embodiment 1.

Table 2

In the table 2, it would be understood that, if 30.0 μm D < 45.0 μm and 220 mm < H. the circularity is less than 1% and the elastic recovery is less than 115%. To the contrary, if D or H is beyond the above range, the circularity (%) exceeds 1.0%) and the elastic recovery exceeds 115%).

Embodiment 3

The following table 3 shows an effects of the ratio S/G of the length S and the diameter G of the nozzle hole 81 , influenced on circularity and M (a distance between the nozzle 72 and a position where the diameter φ of the spun filament is coincided with the diameter G of the nozzle hole). Experimental conditions other than S/G and G are identical to those of the embodiment 1.

Table 3

As shown in the table 3, it would be understood that, if S/G is less than 2.5 or more than 3.5, the circularity becomes greater than 1%>, which is not suitable for production of yams, and M is also less than 50 mm, which means that properties are significantly deteriorated.

Embodiment 4

The following table 4 shows an effect of J (a distance between the discharge hole 79a nearest to the center 73 of the nozzle and the discharge hole 79b farthest from the center 73), influenced on strength of the yam. Experimental conditions other than J are identical to those of the embodiment 1.

Table 4

As shown in Table 4, it would be understood that, if J exceeds 6.0 mm, the strength of the polyamide yam becomes less than 4.5 g/d, so its properties are significantly deteriorated.

Embodiment 5 In addition, the following table 5 shows an effect of a distance K between a surface of the cooling filter 10 and a discharge hole nearest to the surface of the cooling filter 10, influenced on strength of the yarn. Experimental conditions other than K are identical to those of the embodiment 1.

Table 5

As shown in the table 5, it would be understood that, if K is less than 2 mm or more than 10 mm, strength of the polyamide yam becomes less than 4.5 g/d, so its properties are significantly deteriorated.

The present invention has been described in detail. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

INDUSTRIAL APPLICABILITY

The chemical yam manufacturing apparatus according to the present invention, the cooling filter, the nozzle and the quenching air isolation unit provided therein give

the following effects.

First, it is possible to manufacture a filament with improved properties by

optimizing a velocity profile of the quenching air ejected from the cooling filter. Second, it is possible to manufacture a filament with improved properties by

optimizing an amount of the quenching air ejected from the cooling filter.

Third, it is possible to manufacture a filament with improved properties by

isolating the quenching air from being dispersed to the nozzle in order to prevent

decrease of temperature of the polymer melt in the nozzle. Fourth, it is possible to manufacture a filament with improved properties by

selectively heating an air adjacent to the nozzle.

Fifth, it is possible to minimize die swelling of a filament spun through the

nozzle and improve circularity of the manufactured filament.

Sixth, it is possible to improve strength of a yam to be made by minimizing

difference of filaments spun through each nozzle hole.

Seventh, it is possible to manufacture a filament with improved properties by

optimizing a distance between a surface of the cooling filter and a discharge hole nearest

to the surface of the cooling filter so as to effectively cool the filament.

Eighth, it is possible to manufacture a filament with improved properties by

to the surface of the cooling filter.

Claims

What is claimed is:

1. A chemical yarn manufacturing apparatus, comprising a cooling filter

having a cooling region where a quenching air is ejected, wherein a lower portion of the

cooling region has a thicker section than an upper portion thereof.

2. The chemical yarn manufacturing apparatus according to claim 1, further

comprising a nozzle that includes: a downward inclined surface formed at a predetermined angle from a center of

an upper surface of the nozzle to a position adjacent to a side of the nozzle; a discharge hole vertically formed from the position adjacent to the side to a

position adjacent to a lower surface of the nozzle; and a nozzle hole communicated with an end of the discharge hole to be capable of

spinning a polymer melt, wherein the nozzle satisfies the following formula:

2.5 < S/G < 3.5 (0.1 mm ≤ G < 0.18 mm) where S is a length of the nozzle hole, and G is a diameter of the nozzle hole.

3. The chemical yam manufacturing apparatus according to claim 1 or 2, further comprising: a quenching air isolation unit installed to a predetermined position adjacent to

the nozzle that spins a filament so as to isolate a quenching air ejected from the cooling filter from being dispersed to the nozzle.

4. The chemical yarn manufacturing apparatus according to claim 1 or 2,

further comprising: a quenching air supply means including a cap member installed to a lower

portion of the cooling filter and communicated with the cooling filter, and an arm

communicated with the cap member to supply a quenching air; a ring installed between the cooling filter and the cap member to minimize

contacts between a filament and the cooling filter and between the filament and the cap

member, the ring having a perforation of a predetermined size therein so that the

quenching air is passed through; and a filament guide means installed to a portion of the arm where the filament

passes so as to minimize contact between the filament and the arm.

5. A cooling filter, comprising a cooling region where a quenching air is

ejected to cool a filament spun from a nozzle, wherein a lower portion of the cooling

region has a thicker section than an upper portion thereof.

6. The cooling filter according to claim 5, wherein the cooling filter is configured so that a lower end of the cooling region

has a thicker section than an upper end thereof, and a sectional thickness of the cooling

region is linearly changed between the upper end and the lower end.

7. The cooling filter according to claim 6, wherein the sectional thickness of the upper and lower ends of the cooling region

satisfies the following formula: l < Tι T₂ ≤ 1.2 where Ti is a sectional thickness of the lower end of the cooling region where

filter.

8. The cooling filter according to any of claims 5 to 7, wherein a diameter of a micro pore of the cooling filter where the quenching air

is ejected, and a length of the cooling region satisfy the following formula:

30 μm < D < 45 μm

and H is the length of the cooling region where the quenching air is ejected.

9. A nozzle, comprising: a downward inclined surface formed at a predetermined angle from a center of

spinning a polymer melt, wherein the nozzle satisfies the following formula:

10. The nozzle according to claim 9, wherein the discharge hole satisfies the following formula: 2 mm < K ≤ 10 mm (60 mm < W < 300 mm) where K is a distance between a surface of a cooling filter and a discharge hole

11. The nozzle according to claim 9 or 10, wherein the discharge hole satisfies the following formula: J ≤ 6 mm wherein J is a distance between a discharge hole nearest to the center and a

discharge hole farthest from the center.

12. A quenching air isolation unit, installed to a predetermined position

adjacent to a nozzle that spins a polymer melt so as to isolate a quenching air ejected

from a cooling filter from being dispersed to the nozzle, wherein the quenching air

isolation unit comprises a plate having a first perforation of a predetermined size so that

a filament spun from the nozzle passes through the first perforation and the cooling

filter is selectively inserted into the first perforation.

13. The quenching air isolation unit according to claim 12, further

comprising a sub plate installed to the plate, wherein the sub plate has a second perforation corresponding to the first

perforation so that the filament passes through the second perforation and the cooling

filter is selectively inserted into the second perforation.

14. The quenching air isolation unit according to claim 13, wherein the sub plate includes a heating means for selectively heating air

between the nozzle and the sub plate.