KR101260650B1 - Manufacturing method for low-shrinkage polypropylene yarn for sea-bottom cable protection - Google Patents

Abstract

PURPOSE: A manufacturing method of low shrinkage polypropylene yarn for submarine cables is provided to prevent the yarn from being damaged due to external impacts by increasing tensile load. CONSTITUTION: A raw material including polypropylene is produced into a melted polypropylene by an extruder(S12). The melted polypropylene is shaped into a polypropylene sheet is shaped by T-die molding(S13). The area of the polypropylene sheet after stretching treatment is 5.8 to 6.2 times as large as the area of the polypropylene sheet before the stretching treatment. A polypropylene yarn which has a diamond lattice structure is produced by a mesh process(S17). [Reference numerals] (AA) Start; (BB) End; (S11) Transfer a polypropylene-containing raw material to an extruder through a hopper; (S12) Extrude the polypropylene-containing raw material to form extruded melted polypropylene; (S13) Form a polypropylene sheet from the extruded melted polypropylene with a T-die method; (S14) Cool the polypropylene sheet using a cooling bath; (S15) Transfer the polypropylene sheet to a stretching oven using guide rollers and cut the polypropylene sheet; (S16) Stretch the polypropylene sheet by heating; (S17) Produce a submarine polypropylene yarn using softening by tension of multiple transfer rollers and a mesh process by a needle split method; (S18) Transfer the submarine polypropylene yarn to a stabilizing oven which performs stabilization by heating; (S19) Wind the submarine polypropylene yarn

Description

Manufacturing method for low-shrinkage polypropylene yarn for sea-bottom cable protection

The present invention relates to a method for producing a low shrinkage polypropylene yarn for seabed, which can withstand a lot of external shocks, and lowers the shrinkage rate due to thermal denaturation to 3% or less to prevent any external change due to shrinkage when used for seabed. It relates to a low shrinkage seabed polypropylene yarn production process to be maintained.

Subsea installations, especially submarine cables, are placed on the sea floor for communication between two isolated points across the ocean, such as continents and continents, land and islands. However, in areas where fishing activities are active, submarine cables are easily damaged by anchors and other fishing vessels of ships, and cables are easily damaged by natural phenomena such as sea currents caused by currents and waves, and friction with sea floors. .

In order to prevent damage caused by external force of the submarine cable, an insertion member into the release cable to increase the tensile load has been developed and used.

Polypropylene is mainly used as an insertion member to prevent damage to submarine cables. Polypropylene is one of the larger types of alkyl polymers in addition to polyethylene. The flowability, creep resistance and processability are polyethylene. Compared with), it is very excellent, and in particular, it is excellent in insulation because it consists only of carbon and hydrogen in electrical properties. And polypropylene has the advantage that it can be procured at a low price by using a large amount of propylene made from by-products when refining petroleum.

However, polypropylene has a disadvantage that the melting point (℃) is 167 ℃ and the heat denaturation temperature (℃) corresponds to 115 ℃ shrinkage of about 6% shrinkage even at a relatively high temperature.

[Related Technical Literature]

1. TWIST WINDING APPARATUS OF SYNTHETIC RESIN FLAT YARN (Patent Application No. 10-2010-0026028)

2. Manufacturing method of subsea solid cable and subsea solid cable (PROCESS FOR PRODUCING SUBMARINE SOLID CABLE AND SUBMARINE SOLID CABLE) (Patent Application No. 10-2010-7004240)

The present invention is to solve the above problems, to reduce the shrinkage rate due to thermal denaturation to the polypropylene yarn for seabed to 3% or less, low shrinkage for maintaining the physical properties of any external changes due to shrinkage when used for seabed It relates to a process for producing polypropylene yarn for seabed.

In addition, the present invention is to provide a method for producing a low-shrinkable polypropylene yarn for low shrinkage to improve the tensile load in order to prevent damage not only shrinkage, but also damage due to natural phenomena or external forces.

However, the objects of the present invention are not limited to the above-mentioned objects, and other objects not mentioned can be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a method for manufacturing a low shrinkage polypropylene yarn according to a first embodiment of the present invention is a method for forming a polypropylene extrusion melt from a polypropylene raw material by an extruder and then molding the polypropylene sheet into a polypropylene sheet. Stage 1; A second step of performing heating type stretching according to transfer to the stretching oven by the guide roller for the polypropylene sheet to achieve an area ratio of 5.8 to 6.2 times before and after stretching to the polypropylene sheet; A third to produce a polypropylene yarn for the seabed having a diamond lattice structure according to a mesh process by a needle split method together with the softening of the stretched polypropylene sheet utilizing tension by a multi-feed roller; step; And a fourth step of transferring the seabed polypropylene yarn to the stabilization oven by the multi-feed roller to perform stabilization by heating. .

At this time, the second step, it is preferable to perform the state in which the temperature inside the drawing oven is set to 190 ℃ to 210 ℃.

In addition, the fourth step is preferably performed by setting the temperature inside the stabilization oven at a ratio of 1.3 to 1.4 times the temperature inside the stretching oven.

In addition, the fourth step is preferably performed in a state in which the temperature inside the stabilization oven is set to 265 ° C to 280 ° C.

In addition, prior to the first step, the step of transferring the polypropylene raw material to the extruder by a hopper; Further comprising, the polypropylene raw material is preferably a homo-polymer polypropylene (Homo-Polymer Polypropylene) raw material.

In addition, the polypropylene raw material of the first stage is a homopolymer of propylene or a block or an irregular copolymer with another α-olefin having 2 to 8 carbon atoms, and the α-olefin is 1-butene (1-butene). ), 1-pentene, 1-hexene and 1-octene.

In addition, the amount of the α-olefin copolymerized with the propylene in the first step is preferably 0.001 to 50 mol% per mol of the propylene.

In addition, the polypropylene raw material of the first step, the weight average molecular weight is 300,000 g / mol or more, the melt index is 0.1 to 10 g / 10 minutes (230 ℃), molecular weight distribution (PI) is 6 or more, the melt strength It is preferable that is 50 mN or more.

In addition, when producing the polypropylene extrusion melt by the extruder of the first step, the polypropylene raw material is used that the concentration of polypropylene resin (65) to 85wt.%, At a temperature of 100 to 220 ℃ It is preferable to dissolve.

In addition, the extruder of the first step, using a synthetic resin foam sheet extruder, a cylinder for melting and mixing the polypropylene raw material introduced by the hopper, a screw for mixing and conveying the polypropylene raw material installed in the cylinder, the screw It is preferably formed to include a heater installed for heating to the polypropylene raw material.

In addition, the first step, using a T-die method for controlling the flow rate of the molten polypropylene extrusion melt by the synthetic resin foam sheet extruder to control the dickness for forming the polypropylene sheet, the foaming It is preferable to control the flow rate with respect to the type polypropylene extrusion melt by a pneumatic drive system.

In addition, between the first step and the second step, the cooling step of cooling the polypropylene sheet for 10 seconds to 20 seconds using a cooling bath containing water of 25 ℃ to -4 ℃; It is preferable to further include.

In the second step, the blade is erected in a direction opposite to the machine direction (MD) formed at the final end of the guide roller just before transfer of the cooled polypropylene sheet to the drawing oven for the polypropylene sheet. A cutting step of performing cutting using the variable cutter; It is preferable to further include.

In addition, the variable cutter of the cutting step, having 1 to 10 blades, each blade is set variably in a step-up / down manner up and down, the width of the final polypropylene yarn for seabed (Width It is preferable to allow the production according to the standard of).

The needle split method of the third step may be performed by rotating the needle split roller in a state in which the needle split roller is formed upward along the outer circumferential surface of the lattice needle so that the polypropylene sheet passes. It is preferable.

In addition, the multi-stage feed roller of the third step is formed by a pair of feed rollers comprising at least two pairs of upper feed rollers and lower feed rollers, each of the feed rollers has an internal set temperature of the stabilization oven therein. It is desirable to keep the heated oil filled within an error range of ± 10 ° C.

Further, after the fourth step, a fifth step of performing the winding using the synthetic resin flat yarn twist winding device for the polypropylene yarn for seabed; Is preferably performed further.

In addition, the fifth step, the 5-1 step for transferring to the synthetic resin flat yarn twist winding device for the polypropylene yarn for seabed; A 5-2 step of performing 20 twists per meter for the seabed polypropylene yarn by the synthetic resin flat yarn twist winding apparatus; And a fifth step of winding the outer diameter of the bobbin fitted to the take-up roll using a tension on the twisted seabed polypropylene yarn so that the outer diameter is constant. It is preferable to include.

In order to achieve the above object, a low shrinkage seabed polypropylene yarn manufacturing method according to a second embodiment of the present invention, the first step of transferring the polypropylene raw material to the extruder by a hopper; A second step of forming the polypropylene raw material by using an extruder to produce a polypropylene extrusion melt and then molding the polypropylene sheet into a polypropylene sheet; A third step of cooling the polypropylene sheet for 10 seconds to 20 seconds using a cooling bath containing water at -4 ° C to 25 ° C; The polypropylene sheet cooled immediately before transfer to the drawing oven by the guide roller for the polypropylene sheet is cut using a variable cutter whose blade is erected in a direction opposite to the machine direction (MD) formed at the end of the guide roller. Performing a fourth step; A fifth step in which heating-type stretching is carried out by transfer to a drawing oven by a guide roller for the cut polypropylene sheet to achieve an area ratio before and after stretching to the polypropylene sheet 5.8 to 6.2 times; Sixth to produce polypropylene yarns for seabeds having a diamond lattice structure according to a mesh process by needle split method together with softening of elongated polypropylene sheet utilizing tension by multiple feed rollers step; A seventh step of transferring the seabed polypropylene yarn to the stabilization oven by the multiple transfer roller to perform stabilization by heating; And an eighth step of performing winding using the synthetic resin flat yarn twist winding apparatus for the seabed polypropylene yarn; It includes, The seventh step, characterized in that the temperature inside the stabilization oven is set to a ratio of 1.3 to 1.4 times compared to the temperature inside the stretching oven, characterized in that performed.

The low shrinkage seabed polypropylene yarn manufacturing method according to an embodiment of the present invention is to lower the shrinkage rate due to thermal denaturation to the polypropylene yarn for the seabed to 3% or less to prevent any external changes due to shrinkage when used for seabed use Provide the effect of being maintained.

In addition, the method for manufacturing a low shrinkage polypropylene yarn according to another embodiment of the present invention provides a polypropylene yarn having an improved tensile load in order to prevent breakage in addition to shrinkage, but also a large impact due to natural or external force. .

1 is a flow chart showing a method for producing a polypropylene yarn for low shrinkage seabed according to an embodiment of the present invention.
2 is a view for explaining the diamond lattice structure of the polypropylene yarn for seabed prepared by FIG.
3 is a view for explaining the twisted state of the polypropylene yarn prepared by FIG.
4 is a table showing experimental data for the low shrinkage seabed polypropylene yarn prepared by FIG.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a detailed description of preferred embodiments of the present invention will be given with reference to the accompanying drawings. In the following description of the present invention, detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

1 is a flow chart showing a method for producing a polypropylene yarn for low shrinkage seabed according to an embodiment of the present invention. Referring to Figure 1, the propylene (Polypropylene) raw material is transferred to the extruder by a hopper (S11). Here, the polypropylene raw material is a homopolymer-polypropylene (Home-Polymer Polypropylene) raw material. In the present invention, the polypropylene raw material means a block or irregular copolymer of propylene homopolymer or other α-olefin having 2 to 8 carbon atoms. Preferred examples of the α-olefins include 1-butene, 1-pentene, 1-hexene and 1-octene, and are copolymerized with propylene. The amount of α-olefin is 0.001 to 50 mol% per mol of propylene. The weight average molecular weight of the polypropylene should be at least 300,000 g / mol and the melt index should be 0.1 to 10 g / 10 minutes (230 ° C.).

As described above, the polypropylene raw material preferably has a melt index of 0.1 to 10 g / 10 minutes, a molecular weight distribution (PI) of 6 or more, and a melt strength of 50 mN or more.

After step (S11), the polypropylene raw material is extruded using an extruder to form a polypropylene extrusion melt (S12). Herein, the polypropylene raw material is a polypropylene resin having a concentration of 65 to 85 wt.%, And dissolved at a temperature of 100 to 220 ° C.

Here, the extruder may use a synthetic foam sheet extruder. Synthetic resin foam sheet extruder is a cylinder for melt-mixing the polypropylene raw material inputted by the hopper into the hopper, a screw installed in the cylinder to mix and pump the injected polypropylene raw material, and is installed for heating the polypropylene raw material It is preferably formed including a heater. Here, the heater is used that is capable of sufficient heating until the polypropylene raw material reaches the melting point.

After the step (S12), the polypropylene extrusion melt is molded into a polypropylene sheet by the T-die method (S13). That is, a T-die (mould) for controlling the flow rate of the foamed polypropylene extrusion melt melted by the synthetic resin foam sheet extruder is used for controlling the dickness for forming the polypropylene sheet. That is, it is preferable to use a pneumatic drive system to control the flow rate with respect to the polypropylene extrusion melt.

After step S13, the polypropylene sheet molded in step S13 is cooled using a cooling bath (S14). It is preferable that the polypropylene sheet falling below the cooling tank during cooling using the cooling tank is cooled by the cooling water while moving for 10 to 20 seconds by the transfer rollers in the cooling tank. The molded polypropylene sheet is preferably formed by cooling in water at -4 ° C to 25 ° C.

Meanwhile, in another embodiment of the present invention, moisture is attached to the surface of the stretched product of the crystalline polymer in order to highly deform the crystalline polymer forming the polypropylene sheet at a higher speed in the previous step of the oven type stretching in step S16. Then, the polypropylene sheet is stretched using a drawing bath using a high pressure pressurized saturated steam as a drawing medium to make the polypropylene sheet largely deformable than in the conventional drawing method. At this time, by using the pressurized saturated steam having an absolute pressure of the cooling tank of 2.0 kg / cm 2 or more as the stretching medium, the cooling vessel container needs to have a high airtightness so that the pressurized saturated steam does not leak, while the vessel of the cooling vessel has a polypropylene sheet. It is necessary to form an introduction hole for supplying the cooling tank and an extraction hole for taking out pressurized saturated steam into the container.

After step S14, the polypropylene sheet cooled according to step S14 is cut using a variable cutter whose blade is erected in a direction opposite to the machine direction (MD) formed at the end of the guide roller (S15). . In this case, the variable cutter has 1 to 10 corresponding to the number of blades, and each blade can be variably set in a step up / down manner up and down, so that the final production of low shrinkage seabed polypropylene yarn It is possible to manufacture according to the width (Width) standard.

Here, the guide roller serves to remove the water remaining in the polypropylene sheet and harden the shape in the middle of moving the cooled polypropylene sheet through the variable cutter to the stretching oven. To this end, the guide roller preferably includes a plurality of rollers formed vertically downward after moving the polypropylene sheet cooled vertically upward from the cooling bath, thereby allowing the polypropylene sheet to be moved to the stretching oven.

The heating method stretching according to the transfer to the stretching oven by the guide roller for the polypropylene sheet cut in step S15 is performed (S16), whereby the area ratio before and after stretching for each cut polypropylene sheet is 1: 5.8. To 6.2, preferably 1: 6. In this case, the temperature inside the stretching oven is 190 to 210 캜, preferably 200 캜. By heating the polypropylene sheet, the stretching is performed in a state where the chain structure of the polymer constituting the polypropylene sheet is increased, thereby maximizing the stretching efficiency.

The drawing by the drawing oven here should be carried out at 190 to 210 ° C which is within the above-mentioned preferred temperature range. If the temperature is higher than the temperature range, the degree of freedom of the molecules is high, and the orientation of the molecules is poor. In addition, when the temperature is lower than the temperature range, the drawing may not be performed well, and the polypropylene sheet may not be drawn, and a phenomenon of breaking occurs.

After the step (S16), the seabed poly having a diamond lattice structure as shown in Figure 2 according to the mesh (mesh) process by the needle split (needle split) method with the softening of the polypropylene sheet using the tension using the multi-feed roller Polypropylene Yarn is produced (S17). Here, the needle split method allows the polypropylene sheet to pass upward of the needle split roller formed along the outer circumferential surface of the lattice needle, wherein the needle split roller is formed at an entry end for entering the multiple feed roller. Accordingly, a mesh process is performed by rotation of a needle split roller which is rotated to form a diamond lattice for the stretched polypropylene sheet while tension is applied to the plurality of feed rollers for the polypropylene sheet coming out of the stretching oven. As a result, a regular and uniform diamond lattice structure using tension and rotational timing is formed.

In this case, the multi-feed roller includes a pair of feed rollers including an upper feed roller and a lower feed roller, including at least two pairs or more.

In another embodiment of the present invention, a pair of feed rollers are first used in a step S16 to prevent shrinkage of the stretched polypropylene sheet and to stabilize the chain structure of the polymer constituting the polypropylene sheet, rather than stretching the oven inside. The oil heated to a higher temperature can be formed to pass the polypropylene sheet between the upper feed roller and the lower feed roller. Here, the heated oil inside is set similarly within an error range of ± 10 ° C. with the internal set temperature of the stabilization oven in step S18, so that the polypropylene yarn for hedging contracts between the stretching and meshing process and the stabilization process. It provides the effect that can prevent it.

After step S17, the seabed polypropylene yarns generated in step S17 are transferred to a stabilization oven by a plurality of transfer rollers to perform stabilization by heating (S18). After performing stretching in the step S16 by the heating method, the temperature is set at a ratio of 1: 1.3 to 1.4 between the temperature performed for stretching and the temperature for stabilization. That is, the heating temperature on the stabilization oven is preferably carried out at 265 ℃ to 280 ℃.

That is, after stretching, heat setting is performed at 265 ° C to 280 ° C to complete the final seabed polypropylene yarn. The reason for heat setting as described above is to impart structural stability of the fiber after the stretching orientation. The heat setting in the temperature range makes it possible for yarn molecules oriented through the stretching process and the mesh process to continuously maintain the oriented molecular state within the temperature range. By maintaining the oriented molecular state, the strength, which is a physical property, also appears stable. When the temperature of the heat setting is 265 ° C. or less, the heat setting is not performed. When the temperature is 280 ° C. or higher, the molecular chains oriented in the yarn are dispersed, so that the degree of orientation is lowered.

This stabilization process provides an effect of significantly increasing the shrinkage of the physical properties to less than 3% (see FIG. 4), so that the shrinkage during thermal denaturation of the polypropylene yarn for seabed has a slight characteristic.

That is, if the polypropylene sheet stretched by the draw oven is cooled by external temperature contact immediately without stabilization by the stabilization oven, the stretched state is contracted by its contracting force to return to the state before the original stretching. It is to perform heat setting or heat treatment at a higher temperature than the stretching oven to prevent it from becoming.

Polypropylene yarns for low-shrinkage seabeds, such as those described above are wires, sails, fishing nets, filter cloth,

It can be used in various industrial products such as sporting goods, bulletproof, protective, protective gloves, pressure-resistant container, but can be used mainly for the insulation of submarine cables.

After step 18, winding is performed using a synthetic flat yarn twist winding apparatus for the stabilized seabed polypropylene yarn (S19).

The winding process is a first winding step, followed by a transfer step of the polypropylene yarn for seabed to the synthetic flat yarn twist winding device. That is, according to the motor drive of the synthetic resin flat yarn twist winding device, the polypropylene yarn for seabed is wound with a feed roll.

In a second winding step, a twisting step is made on the seabed polypropylene yarn. The seabed polypropylene yarns, which are twisted in accordance with the supply by twisting the seabed polypropylene yarns by the feed rolls and transferred to the inlet of the induction trumpet, gradually reduce the size of the source by the induction trumpet tube and finally the inner diameter becomes smaller. It exits to the exit of the guided fallopian tube in the state, and is transferred to the rearward direction through the switching rod.

In a third winding step, a final winding step using tension for twisted seabed polypropylene yarns is carried out. That is, the twisted seabed polypropylene yarn is finally transferred to the guide roll through the driving roll in the rough state several times in the '∞' type by the driving roll and the driven roll through the driving roll according to the guide roll. Thereafter, the guide roll provides tension so that the twisted seabed polypropylene yarn is constantly wound to the outer diameter of the bobbin fitted to the take-up roll while reciprocating back and forth along the traverse slope.

Accordingly, since the seabed polypropylene yarn is finally wound on the bobbin of the take-up roll in a twisted state by the feed roll and the guide trumpet tube, there is an advantage that the polypropylene yarn for the seabed can be evenly grasped.

Meanwhile, a dyeing process for the seabed polypropylene yarn may be further performed between the step S18 and the step S19, and the seabed polypropylene yarn finally produced when the dyeing process is added may have a shape as shown in FIG. 3A. Twisted black polypropylene yarns, the twisted state may be as shown in Figure 3b.

Figure 4 is for the seabed prepared by the stretching process and the stabilization process when performed at a ratio of 1: 1.3 to 1.4 between the temperature performed for stretching in the step (S16) and step (S18) and the temperature for stabilization This is a chart showing the shrinkage rate and tensile load according to thermal modification at 120 ° C. × 20 min for polypropylene yarns. Referring to FIG. 4, in the first test example for the subsea polypropylene yarn twisted to 1 m per 20 of 3.56 denier with a diameter of 350 mm, an inner diameter of 76 mm, a branch length of 365 mm, the tensile load was 918 N and the shrinkage rate. Was 2.5%.

On the other hand, under the same conditions, in the second test example for the 3.51 denier seabed polypropylene yarn, the tensile load was 916 N and the shrinkage was 2.5%.

That is, the seabed polypropylene yarn according to the present invention was shown to lower the shrinkage rate and increase the tensile load compared to the polypropylene yarn according to the prior art.

Accordingly, thermoplastic elastomers such as styrene-butadiene rubber, styrene-ethylene block copolymer, ethylene-ethylene block copolymer, styrene-styrene block copolymer, and acrylic polymer are added to conventional polypropylene to increase weather resistance and tensile load. Although the manufactured sheet is sold, there is a difficulty in processing due to the side effects of the addition, there is a problem that the transparency is reduced and the whitening phenomenon occurs. In addition, the surface tension is 20 to 28 dyne / cm 2 and far short of 32 to 44 dyne / cm 2 of the vinyl chloride resin has a problem of poor printability and adhesion to other resins. Accordingly, the subsea polypropylene yarns prepared according to the present invention can solve these problems and additionally provide the effect of ensuring dimensional stability, weather resistance, ease of processing and low manufacturing cost.

As described above, the specification and the drawings have been described with respect to the preferred embodiments of the present invention, although specific terms are used, it is only used in a general sense to easily explain the technical contents of the present invention and to help the understanding of the invention. It is not intended to limit the scope of the present invention. It will be apparent to those skilled in the art that other modifications based on the technical idea of the present invention can be carried out in addition to the embodiments disclosed herein.

Claims (19)

A first step of producing a polypropylene extrusion melt by means of an extruder and then molding the polypropylene raw material into a polypropylene sheet;
A second step of performing heating type stretching according to transfer to the stretching oven by the guide roller for the polypropylene sheet to achieve an area ratio of 5.8 to 6.2 times before and after stretching to the polypropylene sheet;
A third to produce a polypropylene yarn for the seabed having a diamond lattice structure according to a mesh process by a needle split method together with the softening of the stretched polypropylene sheet utilizing tension by a multi-feed roller; step; And
A fourth step of transferring the seabed polypropylene yarn to the stabilization oven by the multi-feed roller to perform stabilization by heating; Low shrinkage seabed polypropylene yarn manufacturing method comprising a.
The method according to claim 1,
A low-shrinkable seabed polypropylene yarn manufacturing method, characterized in that carried out in a state in which the temperature inside the drawing oven is set to 190 ℃ to 210 ℃.
The method of claim 2, wherein the fourth step,
A method for producing a low shrinkage polypropylene yarn according to claim 1, wherein the temperature inside the stabilization oven is set at a ratio of 1.3 to 1.4 times the temperature inside the stretching oven.
The method of claim 2, wherein the fourth step,
The low-shrinkable seabed polypropylene yarn manufacturing method characterized in that the temperature in the stabilization oven is carried out in a state set to 265 ℃ to 280 ℃.
The method according to claim 4, Before the first step,
Transferring the polypropylene raw material to the extruder by a hopper; More,
The polypropylene raw material is a low-shrinkable seabed polypropylene yarn manufacturing method, characterized in that the homo-polymer polypropylene (Homo-Polymer Polypropylene) raw material.
The method according to claim 4, wherein the polypropylene raw material of the first step,
Block or irregular copolymers of homopolymers of propylene or other α-olefins having from 2 to 8 carbon atoms,
The α-olefin,
Preparation of low shrinkage seabed polypropylene yarns, characterized in that it is one of 1-butene, 1-pentene, 1-hexene and 1-octene Way.
The method according to claim 6, wherein the amount of α-olefin copolymerized with the propylene of the first step,
A low shrinkage seabed polypropylene yarn manufacturing method, characterized in that 0.001 to 50 mol% per mol of propylene.
The method according to claim 7, wherein the polypropylene raw material of the first step,
A weight-average molecular weight of 300,000 g / mol or more, a melt index of 0.1 to 10 g / 10 minutes (230 ℃), molecular weight distribution (PI) of 6 or more, low shrinkage seabed poly, characterized in that the melt strength is 50 mN or more Process for Making Propylene Yarn.
The method of claim 1, wherein upon producing the polypropylene extrusion melt by the extruder of the first stage,
The polypropylene raw material using a polypropylene resin (polypropylene resin) concentration of 65 to 85wt.%, A low-shrinkable seabed polypropylene yarn manufacturing method characterized in that it is dissolved at a temperature of 100 to 220 ℃.
The method of claim 5, wherein the extruder of the first stage,
A synthetic resin foam sheet extruder, a cylinder for melt-mixing the polypropylene raw material introduced by the hopper, a screw for mixing and conveying the polypropylene raw material is installed inside the cylinder, a heater installed for heating the polypropylene raw material Low shrinkage seabed polypropylene yarn manufacturing method characterized in that it is formed, including.
The method of claim 10, wherein the first step,
In order to control the thickness (dickness) for forming the polypropylene sheet using a T-die method for controlling the flow rate of the molten polypropylene extrusion melt by the plastic foam sheet extruder,
A method for producing a low shrinkage polypropylene yarn for seabed, characterized in that the control of the flow rate with respect to said extrusion melt is carried out by a pneumatic drive system.
The method of claim 11, wherein between the first step and the second step,
A cooling step of cooling the polypropylene sheet for 10 seconds to 20 seconds using a cooling bath containing water at -4 ° C to 25 ° C; Low-shrinkable seabed polypropylene yarn production method further comprising a.
The method of claim 12, wherein the second step,
Cutting the cooled polypropylene sheet immediately before transfer to the stretching oven for the polypropylene sheet using a variable cutter whose blade is erected in a direction opposite to the machine direction (MD) formed at the last end of the guide roller. Cutting step; Low-shrinkable seabed polypropylene yarn production method further comprising a.
The variable cutter of the cutting step,
With 1 to 10 blades, each blade is variably set in a step-up / down manner in the upward and downward directions, so that manufacture according to the specification of the width of the final polypropylene yarn for seabed to be produced is performed. A method for producing a low shrinkage polypropylene yarn for seabed.
The method of claim 14, wherein the needle split method of the third step,
A method for producing a low shrinkage seabed polypropylene yarn, wherein the needle split roller is formed by rotating the needle split roller in a state where the needle split roller is formed along the outer circumferential surface of the lattice.
The method of claim 15, wherein the multiple feed roller of the third step,
A pair of feed rollers consisting of an upper feed roller and a lower feed roller is formed including at least two pairs,
Each feed roller has a low oil shrinkage seabed polypropylene yarn manufacturing method characterized in that the interior of the stabilization oven inside the set temperature of the stabilization oven and the heated oil is maintained in a filled state.
The method according to claim 1, After the fourth step,
A fifth step of winding using the synthetic resin flat yarn twist winding apparatus for the polypropylene yarn for seabed; Low-shrinkable seabed polypropylene yarn production method further comprising a.
The method of claim 17, wherein the fifth step,
A fifth step of transferring the seabed polypropylene yarn to the synthetic flat yarn twist winding apparatus;
A 5-2 step of performing 20 twists per meter for the seabed polypropylene yarn by the synthetic resin flat yarn twist winding apparatus; And
A fifth step of winding the outer diameter of the bobbin fitted to the take-up roll using the tension on the twisted seabed polypropylene yarn so that the outer diameter is constant; Low shrinkage seabed polypropylene yarn manufacturing method comprising a.
A first step of conveying the polypropylene raw material to the extruder by a hopper;
A second step of forming the polypropylene raw material by using an extruder to produce a polypropylene extrusion melt and then molding the polypropylene sheet into a polypropylene sheet;
A third step of cooling the polypropylene sheet for 10 seconds to 20 seconds using a cooling bath containing water at -4 ° C to 25 ° C;
The polypropylene sheet cooled immediately before transfer to the drawing oven by the guide roller for the polypropylene sheet is cut using a variable cutter whose blade is erected in a direction opposite to the machine direction (MD) formed at the end of the guide roller. Performing a fourth step;
A fifth step in which heating-type stretching is carried out by transfer to a drawing oven by a guide roller for the cut polypropylene sheet to achieve an area ratio before and after stretching to the polypropylene sheet 5.8 to 6.2 times;
Sixth to produce polypropylene yarns for seabeds having a diamond lattice structure according to a mesh process by needle split method together with softening of elongated polypropylene sheet utilizing tension by multiple feed rollers step;
A seventh step of transferring the seabed polypropylene yarn to the stabilization oven by the multiple transfer roller to perform stabilization by heating; And
An eighth step of performing winding using the synthetic resin flat yarn twist winding apparatus for the polypropylene yarn for seabed; Including;
The seventh step is a low-shrinkable seabed polypropylene yarn manufacturing method characterized in that the temperature of the stabilization oven is set at a ratio of 1.3 to 1.4 times compared to the temperature inside the stretching oven.

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