KR102202592B1 - Skin Cooling Fabric, Polyethylene Yarn Therefor, and Method for Manufacturing Polyethylene Yarn - Google Patents

Abstract

Disclosed are a cold feeling fabric that can provide not only coolness or coolness, but also a soft touch to a user, a polyethylene yarn for the same, and a manufacturing method thereof. The cooling fabric of the present invention includes a plurality of weft yarns; And a plurality of warps, wherein each of the weft yarns and warp yarns has a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, an elongation at break of 14 to 55%, and an elongation at break of 55 to 85%. It is a polyethylene yarn with crystallinity.

Description

Cold-sensing fabric and polyethylene yarn and polyethylene yarn manufacturing method therefor {Skin Cooling Fabric, Polyethylene Yarn Therefor, and Method for Manufacturing Polyethylene Yarn}

The present invention relates to a cooling fabric and a polyethylene yarn and a polyethylene yarn manufacturing method therefor, and more specifically, to provide a user with not only a cooling feeling or a cooling sensation, but also a soft tactile sensation. It relates to a fabric that can be used, a polyethylene yarn having improved weavability that can be used in the production of the fabric, and a method of manufacturing the yarn.

As global warming progresses, the need for fabrics that can be used for overcoming the heat is increasing. Factors that can be considered in developing a fabric that can be used for overcoming heat include (i) removal of hot factors, and (ii) removal of heat from the user's skin.

As a method focusing on the elimination of the heat source, a method of reflecting light by imparting an inorganic compound to the fiber surface (see, for example, JP 4227837B), a method of scattering light by dispersing inorganic fine particles inside and on the surface of the fiber ( For example, see JP 2004-292982A) and the like have been proposed. However, blocking of such external factors can not only prevent additional heat, but it cannot be a meaningful solution for users who already feel the heat, and there is a limitation that the texture of the fabric is deteriorated.

On the other hand, as a method to remove heat from the user's skin, a method of improving the hygroscopicity of fabric to use the evaporation heat of sweat (see, for example, JP 2002-266206A), and increasing heat transfer from the skin to the fabric. For this, a method of increasing the contact area between the skin and the fabric (see, for example, JP 2009-24272A) has been proposed.

However, in the case of using the evaporation heat of sweat, there is a problem that the consistency cannot be guaranteed because the function of the fabric is highly dependent on external factors such as humidity and the user's constitution, and the method of increasing the contact area between the skin and the fabric In the case of, since the air permeability of the fabric decreases as the contact area increases, a desired cooling effect cannot be obtained.

Therefore, it may be desirable to increase the heat transfer from the skin to the fabric by improving the thermal conductivity of the fabric itself. To this end, JP 2010-236130A proposes to manufacture a fabric using ultra-high-strength polyethylene fiber (Dyneema ^® SK60) having high thermal conductivity.

However, Dyneema ^® SK60 fiber used in JP 2010-236130A is an ultra high molecular weight polyethylene (UHMWPE) fiber having a weight average molecular weight of 500,000 g/mol or more, although it exhibits high thermal conductivity (i ) Due to the high melt viscosity of UHMWPE, since it can only be manufactured by the gel spinning method, there is a problem that environmental problems are caused and the recovery of organic solvents requires enormous costs, and (ii) 28 g/de It has a high tensile strength of more than 759 g/de, a high tensile modulus of more than 759 g/de, and a low elongation at break of 3-4%. There is a problem that it is unsuitable for use in the manufacture of cold-sensitive fabrics.

Accordingly, the present invention relates to a cold-sensitive fabric that can prevent problems due to limitations and disadvantages of the related technology as described above, and a polyethylene yarn and a polyethylene yarn manufacturing method therefor.

One aspect of the present invention is to provide a fabric that can provide a user with a soft touch as well as cool or cool.

Another aspect of the present invention is to provide a polyethylene yarn having improved weavability that can be used in the manufacture of a fabric that can provide a user with a cool or cool feeling as well as a soft touch.

Another aspect of the present invention is to provide a method of manufacturing a polyethylene yarn having improved weavability that can be used in the manufacture of a fabric that can provide a user with a cool or cool feeling as well as a soft touch.

In addition to the viewpoints of the present invention mentioned above, other features and advantages of the present invention will be described below, or from such description will be clearly understood by those of ordinary skill in the art.

According to one aspect of the present invention as described above, including a plurality of polyethylene yarns, each of the polyethylene yarns has a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, and a fracture of 14 to 55% Elongation, and a cool-sensitive fabric, which is a polyethylene yarn having a crystallinity of 55 to 85%, is provided.

The polyethylene yarn may have a crystallinity of 60 to 85%.

The polyethylene yarn may include a polyethylene polymer having a density of 0.941 to 0.965 g/cm ³ , a weight average molecular weight (Mw) of 50,000 to 99,000 g/mol, and a number average molecular weight (Mn) of 10,500 to 14,000 g/mol. have.

The ratio of the weight average molecular weight to the number average molecular weight of the polyethylene (Mw/Mn ratio) may be 5.5 to 9.

The polyethylene yarn may have a total fineness of 75 to 450 denier, and the polyethylene yarn may include filaments having a denier per filament (DPF) of 1 to 5.

The polyethylene yarn may have a circular cross section.

The weight per unit area (area density) of the cooling-sensitive fabric may be 150 to 800 g/m ² , and the thermal conductivity of the cooling-sensitive fabric in the thickness direction at 20°C may be 0.0001 W/cm·° C. or more, and at 20° C. The heat transfer coefficient in the thickness direction of the cool-sensitive fabric may be 0.001 W/cm ² ·° C. or more, and at 20° C., the contact cooling sensation (Q _max ) of the cool-sensitive fabric may be 0.1 W/cm ^{2 or} more.

The cool feeling fabric may be a fabric including the polyethylene yarns as weft yarns and warp yarns.

The cover factor of the fabric defined by Equation 1 below may be 400 to 2,000.

* Equation 1: CF = W _D W _T ^1/2 + F _D F _T ^1/2

Here, CF is the cover factor, W _D is the warp density (ea/inch), W _T is the warp fineness (denier), F _D is the weft density (ea/inch), and F _T is the weft fineness (denier) to be.

According to another aspect of the present invention, having a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, an elongation at break of 14 to 55%, and a crystallinity of 55 to 85%, Polyethylene yarn is provided.

The polyethylene yarn may have a crystallinity of 60 to 85%.

The polyethylene yarn may include a polyethylene polymer having a density of 0.941 to 0.965 g/cm ³ , a weight average molecular weight (Mw) of 50,000 to 99,000 g/mol, and a number average molecular weight (Mn) of 10,500 to 14,000 g/mol. have.

The ratio of the weight average molecular weight to the number average molecular weight of the polyethylene (Mw/Mn ratio) may be 5.5 to 9.

The polyethylene yarn may have a total fineness of 75 to 450 denier, and the polyethylene yarn may include filaments having a DPF of 1 to 5.

The polyethylene yarn may have a circular cross section.

According to another aspect of the present invention, polyethylene having a density of 0.941 to 0.965 g/cm ³ , a weight average molecular weight (Mw) of 50,000 to 99,000 g/mol, and a number average molecular weight (Mn) of 10,500 to 14,000 g/mol Melting the polymer to prepare a spinning dope; Extruding the spinning dope through a confinement having a plurality of holes; Cooling the plurality of filaments formed when the spinning dope is discharged from the holes of the detention; And there is provided a method of manufacturing a polyethylene yarn for a cold-sensitive fabric comprising the step of stretching the multifilament made of the cooled filaments.

The polyethylene may have a melt index (MI) of 1 to 25 g/10min at 190°C.

The ratio of the weight average molecular weight to the number average molecular weight of the polyethylene (Mw/Mn ratio) may be 5.5 to 9.

The stretching step may be performed at a stretching ratio of 2.5 to 8.5.

The general description of the present invention as described above is only for illustrating or describing the present invention, and does not limit the scope of the present invention.

Since the cooling fabric of the present invention is woven from a yarn having high thermal conductivity, it can consistently provide a feeling of cooling to the user regardless of external factors such as humidity.

In addition, the cool feeling fabric of the present invention can continuously provide sufficient cool feeling to the user without sacrificing breathability.

In addition, the cooling fabric of the present invention has the advantage that it can be easily manufactured at a relatively low cost without causing environmental problems and can provide a soft touch to the user.

The accompanying drawings are intended to aid understanding of the present invention and constitute a part of the present specification, illustrate embodiments of the present invention, and describe the principles of the present invention together with the detailed description of the present invention.
1 schematically shows a polyethylene yarn manufacturing apparatus according to an embodiment of the present invention,
Figure 2 schematically shows a device for measuring the contact cooling (Q _max ) of the cold feeling fabric,
FIG. 3 schematically shows an apparatus for measuring thermal conductivity and heat transfer coefficient in the thickness direction of a cool fabric.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the embodiments described below are provided for illustrative purposes only to help a clear understanding of the present invention, and do not limit the scope of the present invention.

It will be apparent to those skilled in the art that various changes and modifications of the present invention are possible within the scope of the technical spirit and scope of the present invention. Accordingly, the present invention includes all changes and modifications falling within the scope of the invention and its equivalents described in the claims.

The cooling fabric according to an embodiment of the present invention may be a woven fabric or a knitted fabric.

In order to provide a fabric having a high thermal conductivity so that a user can feel a sufficient cool feeling, it is preferable that the yarns used in manufacturing the fabric are polymer yarns having a high thermal conductivity.

In the case of a solid, heat is generally transferred through the movement of free electrons and lattice vibration called'phonon'. In the case of metals, heat is mainly transferred in the solid by the movement of free electrons. In contrast, in the case of a non-metallic material such as a polymer, heat is mainly transferred in a solid (especially in the direction of molecular chains connected through covalent bonds) through a phonon.

In order to improve the thermal conductivity of the fabric to the extent that the user can feel a sufficient cool feeling, it is necessary to increase the crystallinity of the polymer yarn to 55% or more, preferably to 60% or more, thereby enhancing the heat transfer ability through the phonon of the polymer yarn. There is.

According to the present invention, high-density polyethylene (HDPE) is used to manufacture a polymer yarn having such a high degree of crystallinity. Compared to a yarn made of low density polyethylene (LDPE) having a density of 0.910 to 0.925 g/cm ³ and a yarn made of linear low density polyethylene (LLDPE) having a density of 0.915 to 0.930 g/cm ³ , 0.941 to 0.965 g/ This is because a yarn made of high-density polyethylene (HDPE) having a density of cm ³ has a relatively high degree of crystallinity.

The high-density polyethylene (HDPE) yarn used in the manufacture of the cooling fabric of the present invention has a crystallinity of 55 to 85%, preferably 60 to 85%.

Meanwhile, high-density polyethylene (HDPE) yarns may be classified into ultra high molecular weight polyethylene (UHMWPE) yarns and high molecular weight polyethylene (HMWPE) yarns according to their weight average molecular weight (Mw). UHMWPE generally refers to a linear polyethylene having a weight average molecular weight (Mw) of 500,000 g/mol or more, whereas HMWPE generally refers to a linear polyethylene having a weight average molecular weight (Mw) of 20,000 to 250,000 g/mol. .

As described above, since UHMWPE yarns such as Dyneema ^® can be produced only by gel spinning due to the high melt viscosity of UHMWPE, there is a problem that environmental problems are caused and enormous costs are required to recover organic solvents.

Since HMWPE has a relatively lower melt viscosity than UHMWPE, melt spinning is possible, and as a result, environmental problems and high cost problems associated with UHMWPE yarns can be overcome.

However, when manufacturing a yarn having a crystallinity of 55 to 85%, preferably 60 to 85% using HMWPE having a weight average molecular weight (Mw) exceeding 99,000 g/mol, the HMWPE yarn finally obtained is 13 Since it has a high tensile strength of g/de or more, a high tensile modulus of 300 g/de or less, and a low elongation at break of 10% or less, the weaving property is not good like UHMWPE yarn and its strength is too high to prevent contact with the user's skin. There is a problem that it is inappropriate to be used in the manufacture of the premise cold-sensitive fabric.

In order to solve such a problem (that is, to enable the manufacture of a fabric that can make the user feel a soft touch, as well as to have good weavability), the polyethylene yarn of the present invention is 55 to 85%, preferably It has a crystallinity of 60 to 85% and a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, and an elongation at break of 14 to 55%.

If the tensile strength exceeds 8.5 g/de, the tensile modulus exceeds 80 g/de, or the elongation at break is less than 14%, not only the weavability of the polyethylene yarn is not good, but the fabric manufactured using it is too stiff. Thus, the user feels uncomfortable. Conversely, if the tensile strength is less than 3.5 g/de, the tensile modulus is less than 15 g/de, or the elongation at break exceeds 55%, if the user continues to use the fabric made from such polyethylene yarn, the fabric will have lint ( pills).

In order to have a crystallinity of 55 to 85%, preferably 60 to 85%, a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, and an elongation at break of 14 to 55%, the present The polyethylene yarn of the present invention may include high-density polyethylene (HDPE) having a weight average molecular weight (Mw) of 50,000 to 99,000 g/mol and a number average molecular weight (Mn) of 10,500 to 14,000 g/mol.

When the weight average molecular weight (Mw) of the HDPE is less than 50,000 g/mol, it becomes difficult for the finally obtained polyethylene yarn to develop a tensile strength of 3.5 g/de or more and a tensile modulus of 15 g/de or more, and as a result, lint on the fabric. Is triggered. On the contrary, when the weight average molecular weight (Mw) of the HDPE exceeds 99,000 g/mol, the weavability of the polyethylene yarn is not good and its stiffness is too high, so it is suitable for the manufacture of a cold-sensitive fabric that is premised on contact with the user's skin. Inappropriate parts arise for use.

The weight average molecular weight (Mw) and number average molecular weight (Mn) of the polyethylene can be measured using the following gel permeation chromatography (GPC) after completely dissolving the polyethylene yarn in a solvent.

-Analyzer: PL-GPC 220 system

-Column: 2 × PLGEL MIXED-B (7.5 × 300mm)

-Column temperature: 160 ℃

-Solvent: Trichlorobenzene (TCB) + 0.04 wt.% dibutylhydroxytoluene (BHT) (after drying with 0.1% CaCl ₂ )

-Dissolution conditions: 160 ℃, 1~4 hours, measuring the solution passed through the glass filter (0.7㎛) after dissolution

-Injector, Detector temperature: 160℃

-Detector: RI Detector- Flow rate: 1.0 ㎖/min

-Injection volume: 200µl

-Standard sample: Polystyrene

According to an embodiment of the present invention, the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the polyethylene (Mw/Mn ratio), that is, the polydispersity index (PDI) is 5.5 to 9 Can be If the PDI of the polyethylene is less than 5.5, flowability is poor due to a relatively narrow molecular weight distribution, and workability during melt extrusion is poor, resulting in thread trimming due to uneven discharge during the spinning process. Conversely, when the PDI of the polyethylene exceeds 9, the melt flowability and processability during melt extrusion are improved due to the wide molecular weight distribution, but the resulting polyethylene yarn has a tensile strength of 3.5 g/de or more because too much low molecular weight polyethylene is included. And it becomes difficult to develop a tensile modulus of 15 g/de or more, and as a result, lint is induced in the fabric.

The polyethylene yarn of the present invention includes filaments having a DPF of 1 to 5, and may have a total fineness of 75 to 450 denier.

In a polyethylene yarn having a predetermined total fineness, when the fineness of each filament, that is, a denier per filament (DPF) exceeds 5 denier, the smoothness of the fabric made of the polyethylene yarn becomes insufficient, and the contact area with the body decreases. Therefore, it is not possible to provide sufficient coolness to the user. In general, the DPF can be adjusted through the discharge amount per hole (hereinafter, "single hole discharge amount") and the draw ratio.

The polyethylene yarn of the present invention may have a circular cross-section or a non-circular cross-section, but it is preferable to have a circular cross-section in that it can provide a uniform cooling sensation to the user.

The cooling-sensitive fabric of the present invention made of the above-described polyethylene yarn may be a fabric or knitted fabric having a weight per unit area (ie, area density) of 150 to 800 g/m ² . If the surface density of the fabric is less than 150 g/m ^{2, the} fabric's density is insufficient and there are many voids in the fabric, and these voids lower the coolness of the fabric. On the other hand, when the surface density of the fabric exceeds 800 g/m ² , the fabric becomes very stiff due to an excessively dense fabric structure, a problem occurs in the user's touch, and problems in use are caused due to the high weight.

According to an embodiment of the present invention, the cooling fabric of the present invention may be a fabric having a cover factor of 400 to 2,000. The cover factor is defined by Equation 1 below.

* Equation 1: CF = W _D W _T ^1/2 + F _D F _T ^1/2

Here, CF is the cover factor, W _D is the warp density (ea/inch), W _T is the warp fineness (denier), F _D is the weft density (ea/inch), and F _T is the weft fineness (denier) to be.

If the cover factor of the fabric is less than 400, there is a problem that the density of the fabric is insufficient, and the cool feeling of the fabric is deteriorated due to too many voids in the fabric. On the other hand, when the cover factor of the fabric exceeds 2,000, the density of the fabric becomes too high, so that the texture of the fabric deteriorates, and problems in use may occur due to the high fabric weight.

The cooling-sensitive fabric of the present invention has a thermal conductivity of 0.0001 W/cm·°C or more in the thickness direction of the fabric at 20°C, and the heat transfer coefficient in the thickness direction of the cool-sensitive fabric is 0.001 W/cm ² ·°C or more at 20°C. to be. In addition, the cooling sensation fabric of the present invention at 20° C. has a contact cooling sensation (Q _max ) of 0.1 W/cm ² or more. A method of measuring the thermal conductivity, heat transfer coefficient, and contact cooling (Q _max ) of the fabric will be described later.

Hereinafter, a method of manufacturing the polyethylene yarn for a cold-sensitive fabric of the present invention will be described in detail with reference to FIG. 1.

First, in order to manufacture a spinning dope by melting polyethylene, an HDPE chip is introduced into the extruder 100.

The polyethylene used in the present invention is a high-density polyethylene (HDPE) having a density of 0.941 to 0.965 g/cm ³ , preferably a weight average molecular weight (Mw) of 50,000 to 99,000 g/mol and a number of 10,500 to 14,000 g/mol It has an average molecular weight (Mn).

In order to manufacture a fabric providing high cooling sensation, the polyethylene yarn must have a high crystallinity of 55 to 85%, preferably 65 to 85%, and in order to manufacture a polyethylene yarn having such a high crystallinity, 0.941 to 0.965 g/ The use of HDPE with a density of cm ³ is essential.

In addition, as described above, when the weight average molecular weight (Mw) of the HDPE is less than 50,000 g/mol, it becomes difficult for the finally obtained polyethylene yarn to exhibit a tensile strength of 3.5 g/de or more and a tensile modulus of 15 g/de or more. , As a result, lint is induced on the fabric. Conversely, when the weight average molecular weight (Mw) of the HDPE exceeds 99,000 g/mol, the weavability of the polyethylene yarn is not good due to excessively high tensile strength and tensile modulus, and its stiffness is too high to prevent contact with the user's skin. It is unsuitable for use in the manufacture of the premise cold-sensitive fabric.

According to an embodiment of the present invention, the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the HDPE (Mw/Mn ratio), that is, the polydispersity index (PDI) may be 5.5 to 9. If the PDI of the HDPE is less than 5.5, flowability is poor due to a relatively narrow molecular weight distribution, and workability during melt extrusion is poor, resulting in thread trimming due to uneven discharge during the spinning process. On the contrary, if the PDI of the HDPE exceeds 9, the melt flowability and processability during melt extrusion are improved due to the wide molecular weight distribution, but the resulting polyethylene yarn has a tensile strength of 3.5 g/de or more because too much low molecular weight polyethylene is included. And a tensile modulus of 15 g/de or more becomes difficult, and as a result, lint is induced on the fabric.

According to an embodiment of the present invention, the HDPE may have a melt index (MI) of 1 to 25 g/10min at 190°C. If the melt index (MI) of HDPE is less than 1 g/10min, it is difficult to ensure smooth flowability in the extruder 100 and uniformity of the extrudate is difficult due to the high viscosity and low flowability of the melted HDPE. I can. On the other hand, when the melt index (MI) of HDPE exceeds 25 g/10min, the flowability in the extruder 100 becomes relatively good, but the finally obtained polyethylene yarn has a tensile strength of 3.5 g/de or more and 15 It can be difficult to have a tensile modulus above g/de.

Optionally, in order to suppress the occurrence of thread trimming and improve productivity, a spinning dope further comprising a fluorine-based polymer in addition to HDPE may be used. The fluorine-based polymer may be, for example, a tetrafluoroethylene copolymer. This spinning dope is a method of (i) injecting a master batch containing HDPE and a fluorine-based polymer into the extruder 100 together with the HDPE chip and then melting therein, or (ii) the HDPE chip. It can be obtained by adding the fluorine-based polymer to the extruder through a side feeder while being injected into the extruder 100 and then melting them together. The fluorine-based polymer may be present in the spin dope in an amount such that the content of fluorine in the spin dope is 50 to 2500 ppm.

The spinning dope is conveyed toward the crest 200 by a screw (not shown) in the extruder 100 and is extruded through a plurality of holes formed in the crest 200. The number of holes in the detention 200 may be determined according to the total fineness of the yarn to be manufactured. For example, when manufacturing a yarn having a total fineness of 75 denier, the imprisonment 200 may have 20 to 75 holes, and when manufacturing a yarn having a total fineness of 450 denier, the imprisonment 200 is It may have 90 to 450, preferably 100 to 400 holes.

The melting process in the extruder 100 and the extrusion process through the detention 200 are preferably performed at 150 to 315°C, preferably 250 to 315°C, and more preferably 265 to 310°C. That is, it is preferable that the extruder 100 and the detention 200 are maintained at 150 to 315 °C, preferably 250 to 315 °C, more preferably 265 to 310 °C.

When the spinning temperature is less than 150° C., spinning may be difficult because uniform melting of HDPE is not achieved due to the low spinning temperature. On the other hand, if the spinning temperature exceeds 315°C, thermal decomposition of HDPE may be caused, and thus it may be difficult to develop high strength.

L/D, which is a ratio of the hole length L to the hole diameter D of the detention 200, may be 3 to 40. If L/D is less than 3, die swell occurs during melt extrusion and the elasticity behavior of HDPE becomes difficult to control, resulting in poor spinnability, and if L/D exceeds 40, it passes through detention (200). In addition to trimming due to necking of the molten HDPE, uneven discharge due to pressure reinforcement may occur.

As the spinning dope is discharged from the holes of the detent 200, the spinning dope begins to solidify due to a difference between the spinning temperature and room temperature, thereby forming semi-solidified filaments. In this specification, both the semi-solidified filaments as well as the fully-solidified filaments are collectively referred to as "filament".

The plurality of filaments 11 formed while spinning dope is discharged from the holes of the detention 200 are completely solidified by being cooled in a cooling unit (or “quenching zone”) 300. Cooling of the filaments 11 may be performed by air cooling.

The cooling of the filaments 11 in the cooling unit 300 is preferably performed to be cooled to 15 to 40° C. using a cooling wind of 0.2 to 1 m/sec. If the cooling temperature is less than 15 °C, trimming may occur in the drawing process due to insufficient elongation due to supercooling. If the cooling temperature exceeds 40 °C, the fineness deviation between the filaments increases due to solidification unevenness, and trimming occurs during the stretching process. I can.

Subsequently, the cooled and completely solidified filaments 11 are collected by a concentrator 400 to form a multifilament 10.

Optionally, as illustrated in FIG. 1, the method of the present invention includes the cooled filaments 11 using an oil roller OR or an oil jet before forming the multifilament 10. ) May further include the step of applying an emulsion. The step of imparting the emulsion may be performed through a metered oiling (MO) method.

Optionally, the step of forming the multifilament 10 through the concentrator 400 and the step of applying the emulsion may be performed simultaneously.

The polyethylene yarn of the present invention can be manufactured by once winding the multifilament 10 as an undrawn yarn and then stretching the undrawn yarn at a draw ratio of 2.5 to 8.5, preferably 3.5 to 7.5. That is, the polyethylene yarn of the present invention can be manufactured through a two-step process of once manufacturing an undrawn yarn by melt spinning HDPE and then stretching the undrawn yarn.

Alternatively, as illustrated in FIG. 1, the polyethylene yarn of the present invention may be manufactured through a direct spinning (DSD) process. That is, the multifilament 10 is directly transferred to the multistage stretching unit 500 including a plurality of godet roller parts GR1...GRn, and multistage stretched at a total draw ratio of 2.5 to 8.5, preferably 3.5 to 7.5. After it can be wound around the winder (600). Such a direct spinning (DSD) process is advantageous in terms of productivity and manufacturing cost compared to the two-step process.

If the draw ratio applied in the drawing process is less than 2.5, (i) the finally obtained polyethylene yarn cannot have a crystallinity of 55% or more, so that the fabric made of the yarn cannot provide sufficient cool sensation to the user, and (ii) Since the polyethylene yarn cannot have a tensile strength of 3.5 g/de or more, a tensile modulus of 15 g/de or more, and an elongation at break of 55% or less, lint may be induced on a fabric made of the yarn.

On the other hand, when the draw ratio exceeds 8.5, the polyethylene yarn finally obtained cannot have a tensile strength of 8.5 g/de or less, a tensile modulus of 80 g/de or less, and a breaking elongation of 14% or more, and thus the weavability of the polyethylene yarn. Not only is it not good, but the fabric manufactured using this is too stiff, which makes the user feel uncomfortable.

When the linear speed of the first godet roller part GR1 that determines the spinning speed of the melt spinning of the present invention is determined, the total draw ratio of 2.5 to 8.5, preferably 3.5 to 7.5 in the multistage drawing unit 500 To be applicable to the filament 10, the linear speed of the remaining godet roller portions is appropriately determined.

According to an embodiment of the present invention, by appropriately setting the temperature of the godet roller parts GR1...GRn of the multistage stretching part 500 in a range of 40 to 140°C, polyethylene through the multistage stretching part 500 Heat-setting of the yarn can be performed. For example, the temperature of the first godet roller part GR1 may be 40 to 80 °C, and the temperature of the last godet roller part GRn may be 110 to 140 °C. The temperature of each of the godet roller parts other than the first and last godet roller parts GR1 and GRn may be set equal to or higher than the temperature of the godet roller part immediately before the first and last godet roller parts GR1 and GRn. The temperature of the last godet roller part GRn may be set equal to or higher than the temperature of the godet roller part immediately before, but may be set slightly lower than that.

Multi-stage stretching and heat setting of the multi-filament 10 are simultaneously performed by the multi-stage stretching unit 500, and the multi-filament 10, which is multi-stage stretched, is wound around the winder 600, so that the polyethylene yarn for the cold-sensitive fabric of the present invention Is completed.

Hereinafter, the present invention will be described in detail through specific examples. However, the following examples are only for helping the understanding of the present invention, and the scope of the present invention should not be limited thereby.

Example 1

Using the apparatus illustrated in FIG. 1, a polyethylene yarn including 200 filaments and a total fineness of 400 denier was prepared. Specifically, a density of 0.964 g/cm ³ , a weight average molecular weight (Mw) of 98,290 g/mol, a number average molecular weight (Mn) of 11,730 g/mol, and a melt index (MI at 190°C) of 3 g/10min The HDPE chip having the HDPE chip was put into the extruder 100 and melted to obtain a spinning dope, and the spinning dope was extruded through a detention 200 having 200 holes. L/D, which is the ratio of the hole length (L) to the hole diameter (D) of the cap 200, was 6. The detention temperature was 290°C.

The filaments 11 formed while being discharged from the detent 200 were finally cooled to 30° C. by the cooling wind of 0.45 m/sec in the cooling unit 300, and the multifilament 10 by the concentrator 400 It was focused and moved to the multi-stage stretching unit 500.

The multi-stage stretching unit 500 is composed of a total of five stages of godet roller units, and the temperature of the godet roller units is set to 70 to 115°C, and the temperature of the godet roller unit at the rear end is the same as the temperature of the godet roller unit at the front end. Or set higher.

The multifilament 10 was stretched by the multi-stage stretching unit 500 at a total draw ratio of 7.5 and then wound around a winder 600 to obtain polyethylene yarn.

By performing plain weave using the polyethylene yarn as warp and weft, a fabric having a thickness of 0.31 mm (warp density: 30 ea/inch, weft density: 30 ea/inch) was obtained.

Example 2

HDPE chip with a density of 0.958 g/cm ³ , a weight average molecular weight (Mw) of 87,660 g/mol, a number average molecular weight (Mn) of 13,510 g/mol, and a melt index (MI at 190°C) of 6.4 g/10min. Polyethylene yarn was obtained in the same manner as in Example 1, except that this was used. Subsequently, the polyethylene yarn was used as warp and weft to perform plain weaving, thereby obtaining a fabric having a thickness of 0.31 mm (warp density: 30 ea/inch, weft density: 30 ea/inch).

Example 3

HDPE chip with a density of 0.961 g/cm ³ , a weight average molecular weight (Mw) of 78,620 g/mol, a number average molecular weight (Mn) of 12,150 g/mol, and a melt index (MI at 190°C) of 11 g/10min Polyethylene yarn was obtained in the same manner as in Example 1, except that this was used. Subsequently, the polyethylene yarn was used as warp and weft to perform plain weaving to obtain a fabric having a thickness of 0.32 mm (warp density: 30 ea/inch, weft density: 30 ea/inch).

Example 4

Polyethylene yarn was obtained in the same manner as in Example 1, except that the number of filaments constituting the polyethylene yarn (total fineness: 400 denier) was 48. Subsequently, the polyethylene yarn was used as warp and weft to perform plain weaving to obtain a fabric having a thickness of 0.33 mm (warp density: 30 ea/inch, weft density: 30 ea/inch).

Example 5

Polyethylene yarn was obtained in the same manner as in Example 3, except that the number of filaments constituting the polyethylene yarn (total fineness: 400 denier) was 48. Subsequently, the polyethylene yarn was used as warp and weft to perform plain weaving to obtain a fabric having a thickness of 0.33 mm (warp density: 30 ea/inch, weft density: 30 ea/inch).

Comparative example

HDPE chip having a density of 0.961 g/cm ³ , a weight average molecular weight (Mw) of 180,000 g/mol, a number average molecular weight (Mn) of 25,714 g/mol, and a melt index (MI at 190°C) of 0.5 g/10min Polyethylene yarn was obtained in the same manner as in Example 1, except that it was used, and was stretched at a total draw ratio of 14 through a multistage drawing unit 500 composed of a total of eight stages of godet roller units. Subsequently, the polyethylene yarn was used as warp and weft to perform plain weaving to obtain a fabric having a thickness of 0.32 mm (warp density: 30 ea/inch, weft density: 30 ea/inch).

The tensile strength, tensile modulus, elongation at break, and crystallinity of the polyethylene yarns produced by the Examples and Comparative Examples were measured as follows, and the thermal conductivity, heat transfer coefficient, and contact of the fabrics obtained by the Examples and Comparative Examples respectively Cool feeling (Q _max ), and stiffness were measured as follows, and the measurement results are shown in Table 1 below.

* Tensile strength, tensile modulus, and elongation at break of polyethylene yarn

According to ASTM D885 method, tensile strength (g/de), tensile modulus (g/de), and elongation at break (%) of polyethylene yarn using a universal tensile tester of Instron Engineering Corp, Canton, Mass. Were measured respectively. The sample length was 250 mm, the tensile speed was 300 mm/min, and the initial load was set to 0.05 g/d.

* Crystallinity of polyethylene yarn

The crystallinity of the polystyrene yarn was measured using an XRD instrument (X-ray Diffractometer) [manufacturer: PANalytical, model name: EMPYREAN]. Specifically, a sample having a length of 2.5 cm was prepared by cutting a polyethylene yarn, and after fixing the sample to a sample holder, measurement was performed under the following conditions.

-X-ray Source: Cu-Kα radiation

-Power: 45 KV x 25 mA

-Mode: Continuous scan mode

-Scanning angle range: 10~40°

-Scan speed: 0.1°/sec

* Cool feeling of contact of fabric (Q _max )

A fabric sample having a size of 20cm×20cm was prepared and left for 24 hours under the conditions of a temperature of 20±2°C and an RH of 65±2%. Subsequently, in a test environment of 20±2° C. and 65±2% RH, the contact cooling sensation (Q _max ) of the fabric was measured using a KES-F7 THERMO LABO II (Kato Tech Co., LTD.) device. Specifically, as illustrated in FIG. 2, the fabric sample 23 was placed on a base plate (also referred to as'Water-Box') 21 maintained at 20°C, and heated to 30°C. Box (22a) (contact area: 3 cm x 3 cm) was placed on the fabric sample 23 for only 1 second. That is, the other surface of the fabric sample 23, whose one surface is in contact with the base plate 21, was brought into instant contact with the T-Box 22a. The contact pressure applied to the fabric sample 23 by the T-Box 22a was 6 gf/cm ² . Subsequently, the Q _max value displayed on a monitor (not shown) connected to the device was recorded. This test was repeated 10 times, and the arithmetic mean of the Q _max value was calculated.

* Thermal conductivity and heat transfer coefficient of fabric

A fabric sample having a size of 20cm×20cm was prepared and left for 24 hours under conditions of a temperature of 20±2°C and an RH of 65±2%. Subsequently, the thermal conductivity and heat transfer coefficient of the fabric were calculated using a KES-F7 THERMO LABO II (Kato Tech Co., LTD.) device in a test environment of a temperature of 20±2°C and an RH of 65±2%. Specifically, as illustrated in FIG. 3, the fabric sample 23 was placed on the base plate 21 maintained at 20° C., and the BT-Box 22b heated at 30° C. (contact area: 5 cm× 5cm) was placed on the fabric sample 23 for 1 minute. Even while the BT-Box 22b contacts the fabric sample 23, heat was continuously supplied to the BT-Box 22b so that the temperature can be maintained at 30°C. The amount of heat supplied to maintain the temperature of the BT-Box 22b (ie, heat flow loss) was displayed on a monitor (not shown) connected to the device. This test was repeated 5 times, and the arithmetic mean of the heat flow loss was calculated. Subsequently, the thermal conductivity and heat transfer coefficient of the fabric were calculated using Equations 2 and 3 below.

Equation 2: K = (W·D)/(A·ΔT)

Equation 3: k = K/D

Here, K is the thermal conductivity (W/cm·°C), D is the thickness (cm) of the fabric sample 23, A is the contact area (= 25 cm ² ) of the BT-Box 22b, and ΔT Is the temperature difference (= 10°C) on both sides of the fabric sample 23, W is the heat flow loss (Watt), and k is the heat transfer coefficient (W/cm ² ·°C).

* Stiffness of fabrics

The stiffness of the fabric was measured by the Circular Bend method using a stiffness measuring device according to ASTM D 4032.

Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example PE yarn PE Density (g/cm ³ ) 0.964 0.958 0.961 0.964 0.961 0.961 Mw (g/mol) 98,290 87,660 78,620 98,290 78,620 180,000 Mn (g/mol) 11,730 13,510 12,150 11,730 12,150 25,714 Mw/Mn 8.38 6.49 6.47 8.38 6.47 7.00 MI (g/10min) 3 6.4 11 3 11 0.5 Tensile strength (g/de) 6.5 5.7 5.1 6.5 6.0 15.5 Tensile modulus (g/de) 57 51 46 57 53 350 Elongation at break (%) 17 18 18 17 18 7.5 Crystallinity (%) 69 67 66 69 67 73 DPF (de) 2 2 2 8.33 8.33 2 fabric Thickness(mm) 0.31 0.31 0.32 0.33 0.33 0.32 Thermal conductivity (W/cm·℃) 0.000461 0.000453 0.000447 0.000405 0.000398 0.000487 Heat transfer coefficient (W/cm ² ·℃) 0.014752 0.014285 0.014136 0.012342 0.012168 0.015176 Q _max (W/cm ² ) 0.173 0.170 0.166 0.146 0.147 0.170 Lecture (kgf) 0.11 0.11 0.12 0.23 0.22 0.25

100: extruder 200: detention
300: quenching zone 400: focusing part
500: multistage drawing 600: winder

Claims (19)

Including a plurality of polyethylene yarns,
The polyethylene yarn has a density of 0.941 to 0.965 g/cm ³ , a weight average molecular weight (Mw) of 50,000 to 99,000 g/mol, a number average molecular weight (Mn) of 10,500 to 14,000 g/mol, and 1 to 25 g at 190°C Including polyethylene with a melt index (MI) of /10min,
Each of the polyethylene yarns is a polyethylene yarn having a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, an elongation at break of 14 to 55%, and a crystallinity of 55 to 85%,
Cool feeling fabric. The method of claim 1,
The polyethylene yarn has a crystallinity of 60 to 85%,
Cool feeling fabric. delete The method of claim 1,
The ratio of the weight average molecular weight to the number average molecular weight of the polyethylene (Mw/Mn ratio) is 5.5 to 9,
Cool feeling fabric. The method of claim 1,
The polyethylene yarn has a total fineness of 75 to 450 denier,
The polyethylene yarn comprises a plurality of filaments each having a fineness of 1 to 5 denier,
Cool feeling fabric. The method of claim 1,
The polyethylene yarn has a circular cross section,
Cool feeling fabric. The method of claim 1,
The surface density of the cool fabric is 150 to 800 g/m ² ,
At 20°C, the thermal conductivity in the thickness direction of the cool-sensitive fabric is 0.0001 W/cm·°C or more,
At 20°C, the heat transfer coefficient in the thickness direction of the cool-sensitive fabric is 0.001 W/cm ² ·°C or more,
At 20°C, the cooling sensation (Q _max ) of the cooling sensibility fabric is 0.1 W/cm ² or more,
Cool feeling fabric. The method of claim 1,
The cool feeling fabric is a fabric comprising the polyethylene yarns as weft yarns and warp yarns,
Cool feeling fabric. The method of claim 8,
The cover factor defined by the following equation 1 is 400 to 2,000,
Cool Fabric:
* Equation 1: CF = W _D *W _T ^1/2 + F _D *F _T ^1/2
Here, CF is the cover factor, W _D is the warp density (ea/inch), W _T is the warp fineness (denier), F _D is the weft density (ea/inch), and F _T is the weft fineness (denier) being. Density of 0.941 to 0.965 g/cm ³ , weight average molecular weight (Mw) of 50,000 to 99,000 g/mol, number average molecular weight (Mn) of 10,500 to 14,000 g/mol, and melting of 1 to 25 g/10min at 190°C Including polyethylene having an index (MI),
Having a tensile strength of 3.5 to 8.5 g/de, a tensile modulus of 15 to 80 g/de, an elongation at break of 14 to 55%, and a crystallinity of 55 to 85%,
Polyethylene yarn for cold-sensitive fabrics. The method of claim 10,
The polyethylene yarn has a crystallinity of 60 to 85%,
Polyethylene yarn for cold-sensitive fabrics. delete The method of claim 10,
The ratio of the weight average molecular weight to the number average molecular weight of the polyethylene (Mw/Mn ratio) is 5.5 to 9,
Polyethylene yarn for cold-sensitive fabrics. The method of claim 10,
The polyethylene yarn has a total fineness of 75 to 450 denier,
The polyethylene yarn comprises a plurality of filaments each having a fineness of 1 to 5 denier,
Polyethylene yarn for cold-sensitive fabrics. The method of claim 10,
The polyethylene yarn has a circular cross section,
Polyethylene yarn for cold-sensitive fabrics. Density of 0.941 to 0.965 g/cm ³ , weight average molecular weight (Mw) of 50,000 to 99,000 g/mol, number average molecular weight (Mn) of 10,500 to 14,000 g/mol, and melting at 190° C. Manufacturing a spinning dope by melting polyethylene having an index (MI);
Extruding the spinning dope through a confinement having a plurality of holes;
Cooling the plurality of filaments formed when the spinning dope is discharged from the holes of the detention; And
Stretching the multifilament made of the cooled filaments
Containing,
The manufacturing method of polyethylene yarn for cold-sensitive fabric according to claim 10. delete The method of claim 16,
The ratio of the weight average molecular weight to the number average molecular weight of the polyethylene (Mw/Mn ratio) is 5.5 to 9,
Polyethylene yarn manufacturing method for cold-sensitive fabric. The method of claim 16,
The stretching step is performed at a draw ratio of 2.5 to 8.5,
Polyethylene yarn manufacturing method for cold-sensitive fabric.

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