KR101819659B1

KR101819659B1 - Method for improving productivity of synthetic fibers using partial heating of spinneret

Info

Publication number: KR101819659B1
Application number: KR1020160008126A
Authority: KR
Inventors: 함완규; 남인우; 이승진; 김도군; 임기섭; 이주형
Original assignee: 한국생산기술연구원
Priority date: 2016-01-22
Filing date: 2016-01-22
Publication date: 2018-01-17
Also published as: KR20170088148A

Abstract

The present invention relates to a method for producing a synthetic fiber having improved productivity by local heating near a spinning nozzle.
In the melt spinning process, fibers discharged in a fiber form from a spinning nozzle are locally heated directly or indirectly in a short time while passing through a nozzle heating unit disposed under the spinning nozzle, so that the spinning speed or stretching speed is raised, And the equipment structure for local heating is relatively small and simple, so that the energy efficiency is high and productivity of the fiber can be improved while the variation of the cross-sectional area and physical property of the fiber is small.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method of manufacturing a synthetic fiber having improved productivity by locally heating a spinning nozzle,

The present invention relates to a method of producing synthetic fibers having improved productivity by local heating of a spinning nozzle, and more particularly, to a method of manufacturing a synthetic fiber having a spinning nozzle, By controlling the molecular chain entanglement structure of the thermoplastic resin in the thermoplastic resin to increase the spinnability of the spinning fiber and to retard the cooling rate, the spinning speed or the stretching speed is increased to improve the production speed in the spinning region or the stretching region, The present invention relates to a method of manufacturing a synthetic fiber having a relatively small, simple, high energy efficiency structure with a local heating apparatus, and improved productivity with less variation in the cross-sectional area and physical properties of the fiber.

Synthetic fibers made of thermoplastic polymer resins are widely used not only for clothing but also for industrial use because they can be manufactured at a low cost by melt spinning, stretching, and high-speed spinning, with excellent balance of mechanical properties and dimensional stability.

In the melt spinning of the thermoplastic polymer resin, the molten resin is discharged through the nozzle of the spinneret and cooled and solidified. Since the physical properties of the obtained fibers are determined by the history of the temperature and the stress during cooling and solidification, the temperature control of the radiation has an important meaning. In particular, since the resin temperature rapidly drops from the spinning temperature immediately after the discharge, it has a great influence not only on the physical properties of the fiber but also on the formability such as cutting yarn.

As a result of efforts to delay the cooling rate of the discharged fibers and improve the physical properties of the resulting fibers, it is necessary to maintain the temperature of the resin component of the discharged fibers at a temperature higher than the spinning temperature, And is exposed to the high-temperature atmosphere for a long time, the thermal decomposition of the polymeric resin proceeds, and the physical properties, particularly the strength, of the resultant fiber are lowered.

Japanese Patent Application Laid-Open No. 1983-156017 discloses a technique of spinning an unstretched fiber for high strength fiber at a higher speed than the conventional one by disposing an infrared quenching delayed color immediately downstream of the spinneret. However, in the infrared type heating device, This is a low problem.

On the other hand, in order to solve the problem of thermal decomposition of polyester by prolonged exposure to a high-temperature atmosphere, in order to delay the cooling of the monofilament in the semi-solid state formed by discharging the molten polyester through the spinneret, By setting the temperature of the heating hood at a temperature that is equal to or slightly lower than the temperature of the spinneret (i.e., 200 to 300 ° C), the cooling of the monofilaments is delayed and the degree of orientation However, in the delay cooling method described above, the property improvement of the polyester yarn is insignificant.

Korean Patent Laid-Open Publication No. 2015-0104475 proposes to manufacture a polyester fiber including a heat insulating plate disposed between the heating hood and the spinneret to prevent the heat of the heating hood from being transferred to the spinneret.

As another method, Japanese Patent No. 4224813 discloses a method of irradiating laser to a running resin at an energy density of 20 W / cm 2 or more at a position of 15 cm along the radiation from the spinneret surface in polyester melt spinning , It is pointed out that it is difficult to uniformly heat the entire fibers to be discharged.

Accordingly, as a means for controlling the molecular structure in the melt spinning process, development of high strength PET fiber has been reported through spinning nozzle design, laser heating, supercritical gas, and coagulation bath.

In particular, the conventional melt spinning process when the nozzle near to provide a high-strength PET fiber by means of a spinning nozzle designed as an example of the method for local heating, Fig. 8 is an embodiment of the local heating by the direct thermal insulation method of the spinning nozzle, Figure 9 Sectional view taken along the line III-III in Fig.

Specifically, in the melt spinning process, the spinning nozzle 100 is placed in a pack-body 200 held from a pack-body heater 300 provided with a heat source of 100 to 350 캜 So that the multifilaments 112 after the irradiation are passed through the annealing heater 400 of 20 to 200 mm so as to uniformly apply the electric heater having a high temperature from room temperature to 400 DEG C at a constant distance, .

However, the local heating of the multifilament 112 by the annealing heater 400 is not for heating but for maintaining a uniform temperature between the holes 111 in the lower part of the spinning nozzle 100 Since the distance between the multifilament 112 and the annealing heater 400 is long and uniform heating is not applied to the multifilament 112 because the temperature deviation between the use holes 111 is minimized, Do not.

As another method of locally heating the vicinity of the spinneret in the conventional melt spinning process, the fiber diameter of the spinneret is made fine and the CO ₂ laser is irradiated right under the spinneret, so that the PET fiber strength after stretching is 1.68 GPa (13.7 g / den.), and elongation of 9.1%, a high-performance fiber is the production of PET has been reported [Masuda, M., "Effect of the Control of Polymer Flow in the Vicinity of Spinning Nozzle on Mechanical Properties of Poly (ethylene terephthalate) fibers", Intern . Polymer Processing , 2010 , 25 , 159-169].

Fig. 10 shows an embodiment of local heating by laser irradiation directly under the spinning nozzle, and Fig. 11 shows a sectional view taken along the line IV-IV in Fig.

Specifically, after spinning multifilament 112 to the CO ₂ laser irradiation part 410, the CO into the bottom of the spinning nozzle 100, the lower the pack body 200 in such a manner as to direct heating by the _second laser irradiation over 0-3 Mm, and a CO ₂ laser is irradiated at a position of 1 to 10 mm immediately after irradiation.

However, laser heating directly under the spinning nozzle 100 has a feature of heating a specific portion of the multifilament 112 to a high temperature, but is applied to an actual commercialization spinning nozzle 100 having tens to tens of thousands of spinning holes 111 There are difficult limits to do.

The present inventors have made efforts to solve the problems of the conventional method for improving the physical properties in the method for producing synthetic fibers from the melt spinning process. As a result, the inventors have found that the resin melted in the melt spinning process passes through the nozzle heating section It is possible to uniformly heat the whole discharged fibers and to heat the locally heated equipment in a relatively short time so that the structure of the equipment is relatively small and simple so that the energy efficiency is high and the variation rate of the cross section and the physical property of the fiber are small, The present inventors have completed the present invention by confirming that the speed is increased and the production speed is improved in the radiation region or the stretching region.

An object of the present invention is to provide a method for producing a synthetic fiber in which productivity is improved by allowing a resin melted in a melt spinning process to be directly and indirectly heated at a high temperature in a short time by passing through a nozzle heating portion disposed in a spinning nozzle portion.

The present invention is characterized in that a spinning nozzle is provided in a pack body of a spinning device, a thermoplastic resin melt-extruded from an extruder is introduced into the spinning nozzle, a nozzle heating portion is disposed in a spinning nozzle portion discharged in a fiber form from the spinning nozzle,

Immediately after the discharge, the fibers in a molten state are passed through the nozzle heating unit so as to locally heat directly or indirectly to a high temperature enough to control the molecular chain entanglement structure in the molten phase polymer of the thermoplastic resin,

The present invention also provides a method for producing synthetic fibers, wherein the heated fibers are cooled and solidified and then wound up after stretching, wherein the productivity is improved in accordance with the increase of the spinning speed or the stretching speed by the local heating.

The present invention is characterized in that the nozzle heating portion of the first preferred embodiment for achieving the method of producing synthetic fibers having improved productivity by locally heating the spinning nozzle of the present invention.

Specifically, the nozzle heating portion of the first embodiment comprises a nozzle body having a plurality of radiating holes for melt-spinning a thermoplastic resin to form fibers, and a nozzle body disposed below the spinneret of the nozzle body for heating the spinning fiber,

The nozzle heating unit may include a heating body having a hole-type heating hole through which the post spinning fiber passes, or a strip-type heating hole through which a plurality of fibers arranged in a row pass, And a heat insulating material layer.

At this time, the thickness of the heat insulating material layer is 1 to 30 mm, the heating body extends from the heat insulating material layer to a length of 1 to 500 mm, and the heating zone of the fiber including the thickness of the heat insulating material layer and the extension length of the heating body is formed.

A nozzle heating unit according to a second preferred embodiment of the present invention for achieving a method of producing synthetic fibers having improved productivity by local heating of the spinning nozzle of the present invention is disposed on a lower bottom surface of a nozzle body protruding from a pack body of a spinning apparatus, Simultaneously with heating of the hole portion, the fiber is heated after spinning,

The nozzle heating unit may include a hole-type heating hole through which the post-spinning fibers pass, or a heating member formed with a band-shaped heating hole through which a plurality of fibers arranged in a row pass, do.

At this time. The lower position of the nozzle body protruding from the pack body is set to -50 (entering into the pack body) to 300 mm (emerging into the pack body) with reference to the lower part of the pack body, The insertion depth of the heating body is 0 to 50 mm, and the extension length of the heating body extending from the lower portion of the nozzle body is 1 to 500 mm. The insertion depth of the heating body partially inserted into the lower portion of the nozzle body, A heating zone of the fiber is formed including an extension length of the heating body extending from the bottom.

Further, in a feature of the nozzle heating portion according to the second embodiment, a gap is formed between the upper surface of the heating body partially inserted into the lower portion of the nozzle body and the opposing surface of the nozzle body facing the upper surface of the heating body, The depth of insertion of the heating body inserted into the lower part of the body is set to 50 mm so that the heating body simultaneously performs the direct heating of the melted thermoplastic resin in the nozzle body before spinning and the indirect heating of the fiber directly under the nozzle body.

In the nozzle heating section of the first and second embodiments, the hole-type heating hole or the band-type heating hole is formed so that the inner circumferential surface is spaced from the center of the fiber by 1 to 300 mm or less.

The present invention relates to a method for producing a synthetic fiber obtained by a melt spinning process, wherein a nozzle heating unit is provided below a spinning nozzle so that molten fiber fibers, which are radiated near the spinning nozzle hole of the spinning nozzle and in the spinning nozzle portion, So that the productivity can be improved by at least 10% or more in productivity per hour compared with the local unheated treatment by improving the production speed in the spinning or stretching region by increasing the spinning speed or the stretching speed.

In addition, the synthetic fiber manufacturing method of the present invention is advantageous in that the apparatus structure for local heating is relatively small and simple, utilizing the existing processes of the melt spinning process and the stretching process, high energy efficiency, delaying the cooling rate of the fiber, It is possible to mass-produce synthetic fibers at low cost and low initial investment.

Therefore, it is useful for marine and military applications such as tire cord, automobile, train, airplane, ship interior and exterior, civil engineering and construction materials, electronic materials, rope and net based on price competitiveness due to mass production and low cost In addition, lightweight sportswear and clothes such as work clothes, uniforms, furniture and interiors, sporting goods, and life-saving roads are also useful, thus securing a wide range of markets.

The present invention can be applied not only to the field of fibers such as long fibers and short fibers of nonwoven fabric of thermoplastic resin, but also to the field of production of films, sheets, molding, containers and the like using the same.

1 is an example of a process flow chart of a polyester fiber according to the melt spinning method of the present invention,
FIG. 2 is an enlarged view of a spinning nozzle provided with a nozzle heating unit according to the first embodiment of the present invention,
3 is a sectional view taken along a line I-I in Fig. 2,
4 (a) and 4 (b) are sectional views taken along a line I-I in Fig. 2 showing a modification of the first embodiment,
5 is an enlarged view of a spinning nozzle provided with a nozzle heating unit according to a second embodiment of the present invention.
6 is a sectional view taken along a line II-II in Fig. 5,
7 (a) and 7 (b) are sectional views taken along a line II-II in Fig. 5 showing a modification of the second embodiment,
8 is a cross-sectional view of a radiation part of a spinning device provided with a conventional spinneret,
Fig. 9 is a sectional view taken along the line III-III in Fig. 8,
10 is a cross-sectional view of a radiation part of a spinning device provided with another conventional spinning nozzle,
11 is a sectional view taken along the line IV-IV in Fig.

Hereinafter, the present invention will be described in detail.

Fig. 1 is a flow chart of the polyester fiber according to the melt spinning method according to the present invention, in which the polyester resin supplied from the raw material supply part 1 is melt-extruded in the extruder 2, 4) and emits the fibers (F). At this time, the fibers F heated after the spinning are cooled and solidified through the quenching chamber 5 and the cooled fibers F are passed through the first godet roller 6 and the second godet roller 7, Followed by winding (8) to produce a polyester fiber.

Thus, the present invention is provided in a pack body 20 of a spinning apparatus, in which a thermoplastic resin melt-extruded from an extruder flows into a spinning nozzle 10 in a spinning device,

A nozzle heating section (41, 81) is disposed in a spinning nozzle portion discharged from the spinning nozzle in a fiber form, and the fibers in the molten state immediately after the discharge are passed through the nozzle heating section to form a molecular chain entanglement structure of the thermoplastic resin So as to be locally heated, directly or indirectly,

Fig. 2 is an enlarged view of a spinning nozzle provided with a nozzle heating unit according to the first embodiment of the present invention. Fig. 3 is a sectional view taken along a line I-I in Fig. 2. The spinning nozzle 4 includes a pack body 20 And a pack body heater 30 is provided on the outer side of the pack body 20. The spinning nozzle 10 includes a nozzle body 12 having a plurality of spinning holes 11 for melt spinning a thermoplastic resin to form fibers F and a spinning nozzle And heating means for heating the post-spinning fiber (F).

The nozzle body 12 sprays a thermoplastic resin in a molten state through the spinneret 11 to form fibers F. The spinning fibers F are subjected to heat treatment through heating means, The thermoplastic polymer fibers are produced by cooling the fibers F and drawing the cooled fibers F by an in-line stretching machine and then winding.

The heating means directly under the spinning nozzle 10 comprises a heating body 41 having a hole-type heating hole 41a of the same structure and number as those of the spinning hole 11 of the nozzle body 12 And the post-spinning fibers F pass through the heating holes 41a so as not to directly contact (for example, heat conduction) with the heating holes 41a when passing through the heating holes 41a.

To this end, the distance a1 from the inner circumferential surface of the heating hole 41a to the center of the fiber F is preferably set within a range of 1 to 300 mm, more preferably within a range of 1 to 100 mm. The heating hole 41a of the heating hole 41a can maintain a uniform temperature at the same distance in the 360 degree direction from the center of the heating hole 41a.

As a modification of the heating hole 41a, in the case of the spinning nozzle in which the spinning holes 11 are arranged concentrically, as shown in Fig . 4 (a), a plurality of radially arranged spinning nozzles It is also possible to form a band-shaped heating hole 41b in a circular shape so that the fibers F radiated from the hole 11 pass therethrough, or to form the heating hole 41b in the form of a straight line, as shown in FIG. 4 (b) In the case of the spinning nozzles arranged in a row, they can be formed as band-shaped heating holes 41b linearly formed to allow the fibers F radiated from the plurality of spinning holes 11 arranged in a row to pass therethrough. According to the form in which the radiation hole 11 is arranged in the nozzle body 12, it is possible to design various types of band-type heating holes such as arc-shaped and mountain-type, or to combine various types of heating holes have.

Like the heating hole 41a of the hole type, the distance a1 from the inner circumferential surface to the center of the fiber F is within 1 to 300 mm, more preferably within the range of 1 to 100 mm Lt; / RTI >

2, it is preferable that the nozzle body 12 and the heating body 41 are not heat-transferred to each other. For this purpose, a heat insulating material layer 43 is provided between the nozzle body 12 and the heating body 41, Respectively.

The temperature of the nozzle body 12 is equal to the temperature of the pack body heater 30. [ The heat insulating material layer 43 functions to block the heat transfer so that the high temperature temperature provided by the heating body 41 located under the nozzle body 12 is not transmitted to the nozzle body 12, The problem that the raw material composed of the polyester-based polymer resin deteriorates in the nozzle body 12 to deteriorate the physical properties can be prevented. At this time, the material for the heat insulating material layer 43 may be a known heat insulating material that realizes a heat insulating effect, and preferably uses an inorganic high temperature thermal insulating material including glass and a ceramic compound.

The thickness a2 of the heat insulating layer 43 is set such that the distance between the nozzle body 12 and the heating body 41 is in the range of 1 to 30 mm. For example, when the thickness a2 is more than 30 mm, the fibers F formed after spinning from the nozzle body 12 are cooled before being heat-treated by the heating body 41, I do not.

The extension a3 of the heating body 41 is set to 1 to 500 mm from the bonding surface with the heat insulating material layer 43 and the thickness a2 of the heat insulating material layer 43 and the extension length of the heating body 41 (a3) to form a heating zone (40).

That is, the heating zone 40 of the first embodiment has a thickness a2 of the heat insulating material layer 43 set within 1 to 30 mm on the undersurface of the nozzle body 12 and a thickness a2 of 1 to 500 mm from the heat insulating material layer 43 The fiber F is heated indirectly (for example, radiation) while passing through the heating body 41 formed by the extension length a3.

At this time, by setting the distance a4 from the portion directly under the nozzle body 12 to the lower end surface of the pack body 20 within the range of 1 to 30 mm, the entire heat insulating material layer 43 and the heating body 41 ) Is located in the pack body (20). Thereby, indirectly (for example, radiation) heating is performed on all the fibers F immediately after radiation, so that productivity can be improved.

The heating zone 40 including the heating body 41 and the heat insulating layer 43 shown in the first embodiment designed as described above can be immediately applied without directly changing the design of the spinneret 10 to be commercialized, Lowering the cost, and increasing the productivity of the fiber at low cost.

In the heating zone 40 of the first embodiment, the entire fiber F discharged after the spinning is instantaneously heated at a uniform distance and at a high temperature by the heating body 41, whereby the molecular chain entanglement structure in the molten polymer It is possible to prevent the deterioration of the physical properties due to the deterioration of the molten polymer by preventing the high temperature heat from being transmitted to the radiation hole 11 of the nozzle body 12 by the heat insulating layer 43. [ Therefore, when the fibers (F) are formed by applying the heating zone (40) of the first embodiment described above, conventional thermoplastic resins can be applied without limitation, and more preferably, they are particularly advantageous for application of a polymer resin which is weak to heat.

FIG. 5 is an enlarged view of a spinning nozzle equipped with a nozzle heating unit according to a second preferred embodiment of the present invention. FIG. 6 is a sectional view taken along the line II-II in FIG. 5. As shown in FIG. 5, 50 are installed in the pack body 60 of the spinning device and a pack body heater 70 is provided on the outside of the pack body 60.

The spinning nozzle 50 includes a nozzle body 52 having a plurality of spinning holes 51 for melt spinning a thermoplastic resin to form fibers F and a spinning nozzle And heating means for heating the post-spinning fiber (F).

The said heating of the second embodiment means is shown in radial holes (51) and (a) and (b) heating the hole (81a) or Figure 7 of the Hole-type made of the same structure as the number of the nozzle body 52 Shaped heating hole 81b as shown in Fig. 1 and the post-spinning fiber F is made to pass through the heating hole 81a or 81b and the heating hole 81a Or 81b (for example, thermal conduction).

Since the heating holes 81a and 81b are the same as the heating holes 41a and 41b described in the first embodiment, a detailed description thereof will be omitted.

5, the heating means according to the second embodiment has a length b1 of from -50 (inside the pack) to 300 (outside the pack) from the bottom of the pack body 60 without a heat insulating layer directly under the nozzle body 52, (b2) of 0 to 50 mm and an extended length b3 from the lower bottom surface of the nozzle body 52. The nozzle body 52 has a nozzle body 52, A heating body 81 extending from 1 to 500 mm in length and having an insertion length b2 in which the heating body 81 is inserted into the nozzle body 52 and an insertion length b2 extending from the lower bottom surface of the nozzle body 52 A heating zone 80 is formed including the extension length b3 of the heating body 81. [

5, a clearance b4 of 0 to 10 mm is formed between the upper surface of the heating body 81 inserted into the nozzle body 52 and the lower surface of the nozzle body 52 facing the upper surface of the heating body 81 The heating body 81 and the surface of the nozzle body 52 come into direct contact with each other (clearance: 0 mm) and heated by direct or indirect (e.g., conduction or radiation) with a gap b4 of 10 mm maximum, The melted thermoplastic resin is first directly heated (for example, conducted) in the vicinity of the radiation hole 51.

Therefore, the heating zone 80 is formed by the thermoplastic resin melted in the vicinity of the radiation hole 51 in the nozzle body 52 before spinning with the insertion length b2 of the heating body 81 inserted into the lower part of the spinning nozzle 52 (For example, conduction or radiation) by the gap b4 and then by the extension length b3 of the heating body 81 extending from 1 to 500 mm in length, (For example, radiation) of the fibers F discharged before the solidification, which are discharged from the pre-solidification state.

The heating zone 80 according to the second embodiment of the present invention directly transfers the high temperature heat to the vicinity of the radiation hole 51 of the nozzle body 52 due to the structural change of the lower end in the nozzle body 52 which is actually commercialized, (F) is indirectly heated by a heating body (81) formed directly under the heating body (52), thereby controlling the molecular entanglement structure in the polymer by the instantaneous high temperature heating The thermoplastic polymer fibers obtained by the present invention are improved in the stretchability and the cooling rate is delayed, whereby the spinning speed and the stretching speed can be increased to improve the productivity.

Thus, the second embodiment can change the structure of the lower part of the nozzle body 52, which is actually commercialized, and can immediately apply it, so that the initial investment cost can be lowered and the productivity of the synthetic fiber can be improved at low cost.

In order to achieve the same object in the heating means of the first embodiment and the second embodiment described above, the residence time, the flow rate and the flow rate of the molten polymer passing through each of the emission holes 11 and 51 of the nozzle bodies 12 and 52 Optimization of shear rate is required.

Thus, the residence time of the molten polymer per hole is preferably 3 seconds or less, and the flow rate is at least 0.01 cc / min or more. At this time, in the case of the polyester-based polymer, if the residence time exceeds 3 seconds, the molten polymer is exposed to excessive heat for a long time to cause deterioration, and when the flow rate is less than 0.01 cc / min, excessive heat is also exposed to the molten polymer And deterioration problems are undesirable.

In the nozzle bodies 12 and 52 of the first and second embodiments, the shear rate of the wall surface of the radiation holes 11 and 51 is preferably 500 to 100,000 / sec, and the shear rate is 500 / sec , The molecular orientation and structure control effect of the molten polymer due to low shear stress is reduced. When the molecular weight exceeds 100,000 / sec, melt fracture due to the viscoelastic characteristics of the molten polymer occurs, resulting in nonuniformity of the cross- do.

That is, the heating holes 41a, 41b, 81a and 81b of the heating bodies 41 and 81, which are the features of the present invention, are designed to have the same structure and number as the radiation holes 11 and 51 of the nozzle bodies 12 and 52 , And the fibers (F) discharged after spinning are locally heated while passing through the heating bodies (41, 81). In particular, the heating holes 41a and 81a of the hole type maintain the structure of the emission holes 11 and 51 of the nozzle bodies 12 and 52, Are held at a distance of 1 to 300 mm from the center of the nozzle bodies 11 and 51 to maintain the temperature at the same distance in the 360 degree direction from the center of the emission holes 11 and 51 of the nozzle bodies 12 and 52 6).

The band-shaped heating holes 41b and 81b have a linear structure 180 degrees opposite to the emission holes 11 and 51 of the nozzle bodies 12 and 52, And is symmetrical within 300 m (see Figs. 4 and 7).

At this time, the heating holes 41a, 41b, 81a and 81b are designed by an indirect heating method in which the fibers F that are passed through after radiation do not directly touch the heat. The size of the heating holes 41a, 41b, 81a, It is highly likely that the heating bodies 41 and 81 are brought into contact with the fibers F when the distance from the center of the radiation holes 11 and 51 of the bodies 12 and 52 is less than 1 mm, (F) are generated, and the fiber quality and workability are deteriorated. Also, the fiber (F) may be deteriorated due to excessive heat exposure. If it exceeds 300 mm, sufficient heat transfer to the fiber (F) It is difficult to control the molecular chain entanglement structure in the scarf fiber polymer and the effect of improving the physical properties is lowered.

As shown in Figs. 2 and 5, when the hole diameter D is 0.01 to 5 mm and the hole length L is L / D 1 or more, and the number of holes (11, 51) in the nozzle body is one or more.

The pitch between the radiation holes 11 and 51 is 1 mm or more and the radiation holes 11 and 51 have a circular shape in the embodiment of the present invention, -, O, etc.) can also be applied. In addition, two or more kinds of composite spinning such as sheath-core type, side-by-side type and sea-island type can be made through the spinneret including the spinning nozzles 10,

The heating holes 41a and 81a of the heating bodies 41 and 81 of the heating bodies 41 and 81 of the present invention are identical in number to the radiation holes 11 and 51 of the nozzle bodies 12 and 52, A square, a donut, and the like.

The heating elements 41 and 81 can be applied as ordinary electric heating wires. Examples of the heating elements 41 and 81 include a Cu-based and an Al-based cast heater, an electromagnetic induction induction heater, a sheath heater, a flange heater, cartridge heater, a coil heater, a near-infrared heater, a carbon heater, a ceramic heater, a PTC heater, a quartz tube heater, a halogen heater, a nichrome wire heater and the like.

In the first and second preferred embodiments of the spinning nozzle for producing a high-strength thermoplastic fiber according to the present invention, the heating bodies 41 and 81 are arranged such that the temperature difference between the pack bodies 20 and 60 is 0 to 1,500 ° C, At least equal to or higher than the temperature.

The nozzle bodies 12 and 52 are fixed to the pack bodies 20 and 60 maintained at 100 to 350 ° C from the heat sources of the pack body heaters 30 and 70, Is equal to the temperature of the heaters (30, 70). If the temperature of the spinning nozzles 12 and 52 is less than 100 ° C, most of the resin can not be melted and becomes hard to spin. When the temperature exceeds 350 ° C, the physical properties of the fiber deteriorate due to rapid thermal decomposition of the resin, I do not.

At this time, the temperature of the pack body heaters 30, 70 can be controlled by an electric heater or a heat medium.

Thereafter, the melted thermoplastic resin forms the fibers F discharged through the spinning nozzles 10, 50 including the nozzle bodies 12, 52. As the thermoplastic resin, nylon series (Nylon 6 and Nylon 66, Nylon 4, etc.) and olefin series (PP and PE, etc.) may be used in addition to the polyester type polymer (PET, PBT, PTT, PEN, Particularly, in the embodiment of the present invention, polyester fibers are the most preferable, and the present invention can be applied to textile fields such as PET long fibers, short fibers and nonwoven fabrics, and can be applied to the field of production of films, sheets, will be.

The spinning nozzles 10 and 50 of the first and second embodiments can be applied to a melt spinning process in which at least one thermoplastic polymer is used as a raw material. Specifically, the monofilament can be applied to a monofilament alone or a composite spinning process, and a monofilament having a fiber diameter of 0.01 to 3 mm can be provided by performing the spinning at a spinning speed of 0.1 to 200 m / min.

The spinning nozzles 10 and 50 of the first and second embodiments can be used in combination with low speed spinning (UDY, 100 to 2000 m / min), medium to low spinning (POY, 2000 to 4000 m / min) (F) (long fibers) of 0.01 to 100 d / f, alone or in combination, using a spinning and in-line drawing process (HOY, at least 4000 m / min) .

In addition, it can be applied to a staple fiber singly or a composite spinning process at a spinning speed of 10 to 3000 m / min to provide a fiber having a fiber diameter of 0.01 to 100 d / f, and a spinning speed of 100 to 6000 m / (spun-bond and melt blown) single and composite spinning processes which realize a fiber diameter of 0.0001 to 100 d / f. But it can also be applied to polymer resin molding and extrusion processes.

As described above, according to the present invention, the fibers discharged from the spinning nozzle are directly and indirectly heated to a high temperature within a short time while being passed through the nozzle heating unit disposed directly under the spinning nozzle, thereby improving the productivity.

The first factor of this productivity improvement is that by instantly raising the temperature of the discharged fiber, the fiber cooling (solidification) is delayed and the spinning speed can be further increased. The second factor is the increase of the molecular chain entanglement This is caused by the increase of the stretching ratio through the control of the melt structure.

Therefore, the manufacturing method of the present invention can further increase and maximize the production speed in the drawing region as well as the radiation region by performing the local heating method of the spinning nozzle by the design of the specific nozzle heating unit.

Accordingly, a method for producing synthetic fibers having improved productivity by local heating of the spinning nozzle of the present invention is characterized in that the thermoplastic resin melted in the melt spinning process is passed through a nozzle heating unit disposed in a spinning nozzle portion, By controlling the molecular chain entanglement structure in the melt phase polymer to increase the extensibility of the spun fibers and to retard the cooling rate, the spinning speed or stretching speed is increased to provide the result of increased production speed in the spinning or stretching zone.

(PET, IV 1.2), nylon resin (Nylon 6, Rv 2.6)) and polypropylene (PP, MI 25) were used as the synthetic fiber materials, In the case of performing the spinning process, the productivity is improved by at least 10% or more as compared with the case where the local heating is not performed.

From the above, it is confirmed that the method of producing the synthetic fiber having improved productivity by local heating of the spinning nozzle of the present invention is not limited to the material of the synthetic fiber, and it is possible to improve the productivity.

In addition, the spinning nozzles 10 and 50 of the present patent can be applied to conventional spinning nozzles because the equipment structure of the nozzle heating unit for locally heating is small and simple, so that the energy efficiency is high and the existing processes such as the melt spinning process and the stretching process It is possible to lower the initial investment cost and improve the productivity of the synthetic fiber at low cost.

Therefore, it is useful for marine use and military use such as tire cord, automobile, train, airplane, ship interior, civil engineering and construction material, electronic material, rope and net based on price competitiveness due to mass production and low cost In addition, lightweight sportswear and clothes such as work clothes, uniforms, furniture and interiors, sporting goods, and life-saving roads are also useful, thus securing a wide range of markets.

Hereinafter, the operation of the first and second embodiments will be described in detail with reference to specific examples.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The present invention is intended to more specifically illustrate the present invention, and the scope of the present invention is not limited to these embodiments.

< Example 1>

1. Manufacture of polyethylene terephthalate (PET) fiber

The polyethylene terephthalate (PET) resin (intrinsic viscosity 1.21 dl / g) supplied from the raw material supply portion 1 shown in Fig. 1 is melt-extruded in the extruder 2 and held at 300 temperature through the gear pump 3 And flowed into the spinning nozzle 4. At this time, as shown in FIG. 1, a low-speed radiation (1 km / h) is applied from a heat source of a pack-body heater 70 to a pack body 60 maintained at the same temperature as the spinneret 4, min) to obtain unstretched PET fibers (UDY), and then in-line stretching was performed continuously to produce stretched high strength PET fibers. At this time, the heating body 41 having the same hole structure and the same number of heating holes 41a as that of the heat insulating material layer 43 and the discharge hole 11 of the nozzle body 12 is formed directly below the nozzle body 12 And 5 mm and 10 mm length from the lower end of the nozzle body 12, respectively, to form the heating zone 40 of the indirect heating type of the fibers immediately after the discharge. The heating zone 40 composed of the heat insulating material layer 43 and the heating body 41 has a plurality of heating holes 41a having a radius larger than 10 mm at the center of each of the irradiation holes 11 of the nozzle body 12 So that the fiber F is designed to be able to transmit heat without being directly contacted while being passed through.

(1) Radiation condition

Spinning temperature: 300 ℃

Spinning nozzle: Φ 0.5

Discharge amount per hole: 4 g / min

Directly below nozzle Local heater temperature: 400 ℃ or higher

Target fiber properties: Strength 9.0 g / d or more and elongation 25 ± 5% or less

(G / R-1) speed and elongation temperature: 0.5 km / min (85 캜)

Extending: more than 4 times

2. Evaluation of physical properties of PET fiber according to local heating

The PET fibers prepared in Example 1 were produced by performing the first roll spinning speed (G / R-1 speed), the second roll drawing speed (G / R-2 speed) and the stretching ratio shown in Table 1 below, The optimum conditions for the target fiber properties, which are higher than 9 g / d and 25 ± 5%, were observed according to local heating.

As shown in Table 1, the high speed in-line stretching process of the unstretched PET fiber (UDY) was carried out, but the PET fiber of the target physical property was changed by fixing the spinning speed (1 km / min) and changing the stretching speed As a result of the production, it was found that, in the case of heating the fiber with the local heater directly under the nozzle, the elongation speed (production speed) was 5 km / min compared with the conventional elongation speed (production speed) The fiber productivity per hour was increased by about 11.1%.

In addition, the coefficient of variation (CV) of the cross section shows little variation in physical properties between the nozzle and the local heater.

< Example 2>

1. Manufacture of nylon fiber

Nylon 6 resin (relative viscosity Rv 2.6) supplied from a raw material supply portion was melt-extruded into an extruder and was carried out under the following spinning conditions to produce nylon fiber.

(1) Radiation condition

Spinning temperature: 270 ℃

Spinning nozzle: Φ0.5

Discharge amount per hole: 4 g / min

Nozzle direct local heater temperature: 370 ℃ or higher

Target fiber properties: Strength 4.0g / d or more and elongation 30 ± 5% or less

(G / R-1) speed and elongation temperature: 0.5 km / min (85 캜)

3 times or more

2. Evaluation of physical properties of nylon fiber with and without local heating

The nylon fibers prepared in Example 2 were produced by performing the first roll spinning speed (G / R-1 speed), the second roll drawing speed (G / R-2 speed) and the stretching ratio shown in Table 2 below, The optimum conditions for achieving the target fiber property strength of 4.0g / d or more and elongation of 30 ± 5% were observed according to local heating.

As shown in Table 2, the fiber productivity per hour was increased by about 13.3% when the nylon fibers of the target properties were heated with a local heater directly below the nozzle to produce fibers having the target properties at the same spinning speed.

In addition, the coefficient of variation (CV) of the cross section shows little variation in physical properties even when manufactured by heating at a high temperature instantly with a local heater directly under the nozzle.

< Example 3>

1. Manufacture of polypropylene fiber

Polypropylene (PP, MI 25) resin supplied from a raw material supply portion was melt-extruded into an extruder, and was performed under the following spinning conditions to produce a high strength polypropylene fiber.

(1) Radiation condition

Radiation temperature: 230 ℃

Spinning nozzle: Φ 0.5

Discharge amount per hole: 4 g / min

Nozzle direct local heater temperature: 330 ℃ or higher

Target fiber properties: Strength of 3.5g / d or more and elongation of 35 ± 5% or less

(G / R-1) speed and elongation temperature: 0.5 km / min (85 캜)

3 times or more

2. Evaluation of physical properties of polypropylene fiber with or without local heating

The polypropylene fibers prepared in Example 2 were produced by performing the first roll spinning speed (G / R-1 speed), the second roll drawing speed (G / R-2 speed) and the stretching ratio shown in Table 3 , And the optimum conditions that can reach the target fiber property strength of 3.5 g / d or more and elongation of 35 ± 5% were observed according to local heating.

As shown in Table 3, when the polypropylene fibers of the target physical properties were heated to a target physical property at the same spinning speed, the fiber productivity per hour was increased by about 10% when heated with a local heater directly below the nozzle.

< Example 4>

1. Manufacture of polyethylene terephthalate (PET) fiber

A polyethylene terephthalate (PET) resin (intrinsic viscosity of 1.21 dl / g) supplied from the raw material supply part 1 is melt-extruded in the extruder 2 and is supplied to the spinning nozzle 4 maintained at 300 temperature through the gear pump 3, Respectively. At this time, high-spinning PET fibers were prepared from the pack-body heater 70 by being wrapped in the pack body 60 maintained at the same temperature as the spinning nozzle 4. The heat transfer method of the spinning nozzle unit was performed in the same manner as in the first embodiment.

(1) High-speed spinning conditions

Spinning temperature: 300 ℃

Spinning nozzle: Φ 0.5

Discharge amount per hole: 4 g / min

Directly below nozzle Local heater temperature: 400 ℃ or higher

Target fiber properties: Strength of 2.5 g / d or more and elongation of 150 ± 15%

(G / R-1) speed and elongation temperature: 3.0 km / min (RT)

Expansion: 1

As shown in Table 4, when the polyethylene terephthalate (PET) fibers of the target properties were heated to a target physical property at the same spinning speed, the fiber productivity per hour was about 16.7% Respectively.

< Example 5>

1. Manufacture of polypropylene fiber

The polypropylene (PP, MI 25) resin supplied from the raw material supply portion 1 was melt-extruded in the extruder 2 and flowed into the spinning nozzle 4 maintained at 300 temperature through the gear pump 3. At this time, the polypropylene fiber was produced by carrying out high-speed spinning from the pack-body heater 70 in the form packed in the pack body 60 maintained at the same temperature as the spinneret 4. The heat transfer method of the spinning nozzle unit was performed in the same manner as in the first embodiment.

(1) High-speed spinning conditions

Radiation temperature: 230 ℃

Spinning nozzle: Φ 0.5

Discharge amount per hole: 4 g / min

Nozzle direct local heater temperature: 330 ℃ or higher

Target fiber properties: Strength 2.0g / d or more and elongation 150 ± 15% or less

(G / R-1) speed and elongation temperature: 1.0 km / min (RT)

Expansion: 1

As shown in Table 5, when the polypropylene (PP) fibers of the target properties were heated to a target physical property at the same spinning speed, the fiber productivity per hour was increased by about 13.3% Respectively.

As described above, the present invention provides a manufacturing method of a synthetic fiber having improved productivity by allowing fibers discharged from a spinning nozzle in a melt spinning process to be directly or indirectly heated locally at a high temperature in a short time by passing through a nozzle heating unit disposed in a spinning nozzle Lt; / RTI >

That is, in the method of producing the synthetic fiber of the present invention, the heating method is optimized by direct local / indirect local heating method within a short time in the vicinity of the spinneret which is discharged in the fiber form, And the spinning speed can be further increased by delaying the fiber cooling (solidification) by instant heating at a high temperature. By controlling the melting structure of the molecular chain entanglement in the polymer due to the high-temperature local heating, the stretching property of the synthetic fiber yarn can be improved, It is possible to improve the productivity of the synthetic fiber which further increases the production speed in the stretching region as well as the radiation region which is conventionally performed without local heating of the spinning nozzle.

In addition, the manufacturing method of the synthetic fiber of the present invention can improve the productivity while having a relatively small and simple equipment structure for the local heating, high energy efficiency, less fluctuation in the cross-section of the fiber and less variation in physical properties.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art.

1: raw material feeder, 2: extruder, 3: gear pump, 4: spinning nozzle,
5: quenching chamber (radiation), 6: first godet roller, 7: second godet roller, 8:
10, 50: Spinning nozzle 11, 51: Spin hole 12, 52: Nozzle body 20, 60: Pack body
30, 70: Pack-body heater 41, 81:
41a, 41b, 81a, 81b: heating hole 43: heat insulating material layer
F: Fiber

Claims

A spinning nozzle is provided in the pack body of the spinning device, the thermoplastic resin melt extruded from the extruder flows into the spinning nozzle,
The molten fiber discharged from the spinning nozzle is locally heated directly or indirectly to a temperature high enough to control the molecular chain entanglement structure in the molten phase polymer of the thermoplastic resin while passing through the nozzle heating unit,
The heated fiber is cooled and solidified, and the fiber is wound after being drawn,
Wherein the nozzle heating section is formed of a heating body having a heating hole formed in the same number and structure as the radiation holes of the nozzle body of the spinning nozzle and is spaced from the center of the fiber through which the heating hole passes, Wherein productivity is improved as a spinning speed or a stretching speed is increased by local heating in which molten fibers discharged from a plurality of heating holes are passed through respective heating holes.

The nozzle of claim 1, wherein the nozzle heating unit comprises: a nozzle body having a plurality of spinning holes for melt-spinning a thermoplastic resin to form fibers, the nozzle body being disposed below a spinning hole for heating fibers after spinning; And a heat insulating material layer provided between the nozzle body and the heating body, wherein the heating body has a hole-type heating hole for allowing the nozzle body and the heating body to pass through, and a heat insulating material layer provided between the nozzle body and the heating body.

The method of producing a synthetic fiber according to claim 2, wherein the heat insulating material layer has a thickness of 1 to 30 mm and the heating body extends from a heat insulating material layer to a length of 1 to 500 mm.

[2] The apparatus according to claim 1, wherein the nozzle heating unit is disposed on a lower bottom surface of a pack body of the spinneret,
Type heating hole through which the post-spinning fibers pass, or a heating body having a band-type heating hole through which a plurality of fibers arranged in a row pass, wherein a part of the heating body is provided on the lower portion of the nozzle body Wherein the synthetic fiber is produced by a method comprising the steps of:

5. The method of claim 4, wherein a nozzle body protruding from a bottom surface of the pack body is set to -50 to 300 mm with respect to a lower portion of the pack body.

5. The method according to claim 4, wherein the heating body is placed in contact with or partially inserted into the lower part of the nozzle body at a distance of 0 to 50 mm, and an extension length of the heating body extending from the lower part of the nozzle body is 1 to 500 mm. / RTI >

The composite fiber according to claim 4, wherein a gap is formed between the upper surface of the heating body partially inserted into the lower portion of the nozzle body and the opposing surface of the nozzle body facing the upper surface of the heating body Gt;

delete