Method for preparing spunbond non-woven fabrics

Abstract

The present invention relates to a method for preparing spunbond nonwoven fabrics. According to the present invention, a method for preparing spunbond nonwoven fabrics is provided, the method enabling excellent post-processability to be implemented according to the preparation of filaments with excellent strength and fineness.

Description

Method for manufacturing spunbond nonwoven fabric

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0193585, filed December 27, 2023, and Korean Patent Application No. 10-2024-0162923, filed November 15, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a method for manufacturing a spunbond nonwoven fabric.

[0003]

[0004] Spunbond nonwoven fabrics have high productivity and good mechanical properties, and are used in various industrial fields, including filters and protective clothing.

[0005] The filaments that make up conventional nonwoven fabrics have been manufactured by increasing the fineness and strength by using a method such as spinning or changing the process conditions, such as cooling temperature and drawing pressure, to suit the purpose.

[0006] However, the filament manufactured by this method had the problem of not being able to satisfy both high strength and fineness at the same time.

[0007] Typically, nonwoven fabrics manufactured from finely divided filaments have low strength, limiting their application to various applications requiring relatively high strength, such as filters and protective clothing. To address this issue, polyolefin melt-blown and staple polyester nonwoven fabrics are laminated for use as filter media, or surface coatings are applied to enhance strength, achieving high strength and fineness requirements for protective clothing. However, these additional processes increase manufacturing costs.

[0008] Accordingly, in various industries such as filters and protective clothing, research is needed on a filament manufacturing method that can simultaneously achieve high strength and fineness without additional processes.

[0009]

[0010] The present invention provides a method for manufacturing a spunbond nonwoven fabric capable of implementing excellent post-processing properties by using filaments that simultaneously have excellent strength and fineness.

[0011]

[0012] According to one embodiment of the invention,

[0013] A step of manufacturing a filament by melting and spinning a thermoplastic resin;

[0014] A step of drawing the above filament at a temperature of 70°C to 140°C in a heating ejector;

[0015] A step of forming a fiber web by stacking the above-mentioned extended filaments; and

[0016] A step of forming a spunbond nonwoven fabric by heat treating the above fiber web under pressure;

[0017] The above heating ejector includes an ejector and a heater coupled to the ejector,

[0018] A method for manufacturing a spunbond nonwoven fabric is provided, wherein the distance from the inlet of the ejector to the center of the heater is 10 mm or more and 100 mm or less.

[0019] Hereinafter, a method for manufacturing a spunbond nonwoven fabric according to embodiments of the present invention will be described in more detail.

[0020]

[0021] Unless explicitly stated otherwise in this specification, terminology is used only to describe specific embodiments and is not intended to limit the invention.

[0022] As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise.

[0023] As used herein, the term "including" means specifying a particular characteristic, region, integer, step, operation, element and / or component, but does not exclude the presence or addition of other particular characteristics, regions, integers, steps, operations, elements, components and / or groups.

[0024] In this specification, terms including ordinal numbers, such as "first" and "second," are used to distinguish one component from another and are not limited by the ordinal numbers. For example, within the scope of the present invention, the first component may also be referred to as the second component, and similarly, the second component may be referred to as the first component.

[0025] As used herein, "denier" is a unit of fineness based on the mass (grams) per 9000 meters of fiber length. For example, 1 denier can be expressed as 1 g / 9000 m, or 0.11 mg / m, or 0.11 tex.

[0026]

[0027]

[0028] According to one embodiment of the invention, a method for producing a spunbond nonwoven fabric is provided, comprising: a step of producing a filament by melt spinning a thermoplastic resin; a step of drawing the filament at a temperature of 70° C. to 140° C. in a heating ejector; a step of stacking the drawn filaments to form a fiber web; and a step of heat treating the fiber web under pressure to form a spunbond nonwoven fabric; wherein the heating ejector includes an ejector and a heater coupled to the ejector, and a distance from an inlet of the ejector to a center of the heater is 10 mm to 100 mm.

[0029]

[0030] As a result of the research of the present inventors, by including a step of drawing a filament at a temperature of 70°C to 140°C in a heating ejector, as in the method for manufacturing a spunbond nonwoven fabric of the above embodiment, it is possible to manufacture a filament having both excellent strength and fineness, and by using a filament having both excellent strength and fineness, the spunbond nonwoven fabric finally manufactured can have excellent post-processing properties in post-processing such as impregnation, coating, dyeing, grinding, and laminating.

[0031]

[0032] The spunbond nonwoven fabric manufactured according to the method for manufacturing the spunbond nonwoven fabric of the above embodiment can simultaneously realize excellent strength and fineness, and thus can be utilized in manufacturing various filters such as pre-filters, medium-performance filters, HEPA filters, and ULPA filters that require excellent collection performance, and can further be applied to various nonwoven protective clothing markets.

[0033]

[0034] According to one embodiment, the method for manufacturing the spunbond nonwoven fabric may include the step of melt-spinning a thermoplastic resin to produce filaments.

[0035] The above thermoplastic resin can be used in combination of one or more types to manufacture a filament.

[0036] Specifically, the step of melt-spinning the thermoplastic resin to produce a filament may include a step of melt-spinning one type of thermoplastic resin to produce a first filament; or a step of melt-spinning two or more types of thermoplastic resins having different melting points to produce two or more types of filaments.

[0037] The filament obtained in the step of manufacturing the first filament by melting and spinning the above-mentioned one type of thermoplastic resin is drawn at a temperature of 70°C to 140°C in a heating ejector, and this can be drawn alone or mixed with other filaments to form a fiber web.

[0038] In addition, two or more types of thermoplastic resins having different melting points can be melt-spun to produce two or more types of filaments, and these can be drawn at a temperature of 70°C to 140°C in a heating ejector and then mixed to form a fiber web.

[0039] More specifically, the method for manufacturing the spunbond nonwoven fabric may include the steps of: manufacturing polyester filaments; stretching the first polyester filaments at a temperature of 70° C. to 140° C. in a heating ejector; forming a fiber web by laminating the stretched first polyester filaments and second polyester filaments; and heat-treating the fiber web under pressure to form a spunbond nonwoven fabric.

[0040] At this time, the first polyester filament may have a melting point of 250°C or higher, and the second polyester filament may have a melting point of 160°C to 235°C.

[0041] Accordingly, the spunbond nonwoven fabric may include a fiber web in which first polyester filaments having a melting point of 250°C or higher and second polyester filaments having a melting point of 160°C to 235°C are blended.

[0042]

[0043] The above first polyester filament may have a melting point of 250°C or higher, or from 250°C to 265°C, or from 250°C to 260°C, or from 255°C to 260°C.

[0044] For example, the first polyester filament may include at least one first polyester selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytetrafluoroethylene, and copolymers thereof that meet the melting point range.

[0045]

[0046] The second polyester filament may have a melting point that is at least 15° C. lower than the first polyester filament. Preferably, the second polyester filament may have a melting point of 160° C. to 235° C., or 160° C. to 230° C., or 175° C. to 230° C., or 160° C. to 210° C., or 170° C. to 210° C., or 175° C. to 210° C., or 180° C. to 210° C., or 190° C. to 210° C.

[0047] For example, the second polyester filament may include at least one second polyester selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polytetrafluoroethylene, and copolymers thereof that meet the melting point range.

[0048]

[0049] According to one embodiment, the fiber web may comprise the first polyester filaments and the second polyester filaments in a weight ratio of 65:35 to 85:15.

[0050] In order to provide sufficient bonding strength to the fiber web while enabling the effect according to the embodiment to be realized, it is preferable that the second polyester filament is 15 wt% or more based on the weight of the fiber web. However, if the second polyester filament is included in the fiber web in an excessive amount, the mechanical properties of the fiber web may deteriorate due to a decrease in the content of the first polyester filament, and the workability of the spinning process and subsequent processes may deteriorate. Therefore, it is preferable that the second polyester filament is 35 wt% or less, or 30 wt% or less, or 25 wt% or less based on the weight of the fiber web.

[0051] Specifically, the weight ratio of the first polyester filament and the second polyester filament in the fiber web may be 65:35 to 85:15, or 70:30 to 85:15, or 75:25 to 85:15.

[0052]

[0053] According to one embodiment, the first polyester filament comprises a circular cross-section filament.

[0054] Preferably, the first polyester filament may be a circular cross-section filament having a fineness of 1 to 5 denier, or 1 to 4 denier, or 1 to 2 denier, or 1 to 1.5 denier, or 1 to 1.21 denier. In order to secure the bonding strength of the filaments in the fiber web, it is preferable that the first polyester filament have a fineness within the above-described range.

[0055]

[0056] In one embodiment, the second polyester filament may be a circular cross-section filament.

[0057] Preferably, the second polyester filament may be a circular cross-section filament having a fineness of 1 to 5 denier, or 1 to 4 denier, or 1 to 2 denier. In order to secure the bonding strength of the filaments in the fiber web, it is preferable that the second polyester filament have a fineness within the above-described range.

[0058]

[0059] According to one embodiment, the first polyester filament and the second polyester filament may be independently melted and spun through separate spun rods to form the first and second polyester filaments. Alternatively, the first polyester filament and the second polyester filament may be each melted and spun through a single spun rod for mixing, the number and shape of the spun rods of the different resins being controllable, to form the first and second polyester filaments.

[0060]

[0061] In the above melt spinning, the spinning speed and tension can be controlled taking into account the desired fineness of the first and second polyester filaments.

[0062] In addition, it is preferable that the steps of forming the first and second polyester filaments are each performed at a spinning speed of 4000 m / min to 6000 m / min, or 4500 m / min to 6000 m / min, or 4500 m / min to 5500 m / min. In order to form filaments having an appropriate degree of crystallinity, the spinning speed is preferably 4000 m / min or more, or 4500 m / min or more. However, if the spinning speed is excessive, filament entanglement may occur during the spinning process, which may lower the uniformity of the nonwoven fabric. Therefore, the spinning speed is preferably 6000 m / min or less, or 5500 m / min or less.

[0063]

[0064] The first and second polyester filaments are blended to form the fiber web. The blended first and second polyester filaments are laminated on a continuously moving net conveyor by a conventional opening method such as an electrostatic charging method, a collision plate method, and an air current diffusion method to form the fiber web. Here, the fiber web preferably contains 70 to 95 wt% of the first polyester filament and 5 to 30 wt% of the second polyester filament.

[0065]

[0066] The method for manufacturing a spunbond nonwoven fabric of the above embodiment may include a step of manufacturing a filament by melt spinning the thermoplastic resin; and a step of subsequently stretching the filament at a temperature of 70°C to 140°C in a heating ejector.

[0067] As the above manufacturing method includes a step of drawing the filament at a temperature of 70°C to 140°C in a heating ejector, a filament having both excellent strength and fineness can be manufactured, and as the filament having both excellent strength and fineness is used, the spunbond nonwoven fabric finally manufactured can have excellent post-processing properties in post-processing such as impregnation, coating, dyeing, grinding, and laminating.

[0068]

[0069] Specifically, in the step of drawing the filament at a temperature of 70°C to 140°C in a heating ejector, the temperature may be 70°C to 140°C, 80°C to 140°C, 70°C to 130°C, 80°C to 130°C, 70°C to 120°C, or 80°C to 120°C.

[0070] The above temperature can be achieved by controlling the temperature of the heater in the heating ejector to 70°C to 140°C, 80°C to 140°C, 70°C to 130°C, 80°C to 130°C, 70°C to 120°C, or 80°C to 120°C.

[0071]

[0072] In the step of drawing the above filament at a temperature of 70°C to 140°C in a heating ejector, the temperature of the drawing step can satisfy the above range, which is higher than the glass transition temperature and lower than the crystallization temperature of the filament, thereby increasing the density in the axial direction of the filament, thereby implementing a high-strength filament and simultaneously implementing fineness.

[0073]

[0074] Unlike the step of drawing the above filaments at a temperature of 70°C to 140°C in a heating ejector, if the temperature exceeds the above range, it becomes the crystallization temperature of the filaments, causing clumping between the filaments, which may reduce the fine-tuning effect. In addition, if the temperature is lower than the above temperature, the density of the filaments cannot be controlled, which may cause a problem of weakening the strength.

[0075]

[0076] The structure of the above heating ejector is as illustrated in Fig. 2. Specifically, the heating ejector may include an ejector (100) and a heater (103) coupled to the ejector (100).

[0077] The length of the above ejector may be 100 mm or more and 500 mm or less. The length of the above ejector may mean the shortest straight line length from the inlet to the outlet of the ejector.

[0078] Specifically, the length of the ejector may be 100 mm or more, 150 mm or more, 200 mm or more, 300 mm or more, 500 mm or less, 400 mm or less, or 100 mm or more and 500 mm or less, 150 mm or more and 500 mm or less, 200 mm or more and 500 mm or less, 300 mm or more and 500 mm or less, 100 mm or more and 400 mm or less, 150 mm or more and 400 mm or less, 200 mm or more and 400 mm or less, or 300 mm or more and 400 mm or less.

[0079]

[0080] The above heating ejector may have a distance (200) from the inlet (101) of the ejector to the center of the heater (103) of 10 mm or more and 100 mm or less. The length of the ejector may mean the shortest straight line length from the inlet to the outlet of the ejector.

[0081] Specifically, the distance from the inlet of the ejector to the center of the heater is 10 mm or more, 20 mm or more, 30 mm or more, 50 mm or more, 100 mm or less, 80 mm or less, 70 mm or less, 65 mm or less, or 10 mm or more and 100 mm or less, 20 mm or more and 100 mm or less, 30 mm or more and 100 mm or less, 50 mm or more and 100 mm or less, 10 mm or more and 80 mm or less, 20 mm or more and 80 mm or less, 30 mm or more and 80 mm or less, 50 mm or more and 80 mm or less, 10 mm or more and 70 mm or less, 20 mm or more and 70 mm or less, 30 mm or more and 70 mm or less, 50 mm or more and 70 mm or less, 10 mm or more and 65 mm or less, 20 mm or more and 65 mm or less, 30 mm or more and 65 mm or less, 50 mm or more and 65 It can be less than mm.

[0082] In the case where the distance (200) from the inlet (101) of the ejector to the center of the heater (103) is too close, the heated air may leak out and the filament may not be elongated to the set temperature. In the case where the distance (200) from the inlet (101) of the ejector to the center of the heater (103) is too far, the filament may be elongated without heat transfer to the filament.

[0083]

[0084] Meanwhile, the ratio of the distance (200) from the inlet (101) of the ejector to the center of the heater (103) to the length of the ejector may be 0.05 or more and 0.4 or less.

[0085] Specifically, the ratio of the distance (200) from the inlet (101) of the ejector to the center of the heater (103) to the length of the ejector may be 0.05 or more, 0.1 or more, 0.2 or more, 0.4 or less, 0.3 or less, 0.25 or less, or 0.05 or more and 0.4 or less, 0.1 or more and 0.4 or less, 0.2 or more and 0.4 or less, 0.05 or more and 0.3 or less, 0.1 or more and 0.3 or less, or 0.2 or more and 0.3 or less.

[0086] If the ratio of the distance (200) from the inlet (101) of the ejector to the center of the heater (103) to the length of the ejector is too small, a problem of heat not being transferred to the filament may occur, and if the ratio of the distance (200) from the inlet (101) of the ejector to the center of the heater (103) to the length of the ejector is too large, a problem of heat being supplied after the elongation of the filament is already completed may occur, making it difficult to achieve excellent strength or fineness.

[0087]

[0088] The difference in internal diameter between the inlet (101) and outlet (102) of the above ejector may be 2 mm or more.

[0089] Specifically, the difference in internal diameter between the inlet and the outlet of the ejector may be 2 mm or more, 3 mm or more, 10 mm or less, 5 mm or less, 4 mm or less, 2 mm or more and 10 mm or less, 2 mm or more and 5 mm or less, 2 mm or more and 4 mm or less, 3 mm or more and 10 mm or less, 3 mm or more and 5 mm or less, or 3 mm or more and 4 mm or less.

[0090] Since the difference in internal diameter between the inlet (101) and the outlet (102) of the above-mentioned ejector is 2 mm or more, heat flow inside the ejector becomes smooth, so that heat transfer inside the ejector can be performed in a convective manner. When heat transfer inside the ejector is performed in a convective manner, not only is the filament drawing efficiency increased, but also low uniformity and excellent reproducibility of the final filament can be realized.

[0091] If the difference in internal diameter between the inlet (101) and the outlet (102) of the above ejector is less than 2 mm, elongation due to the difference in flow rate does not occur, and thus elongation efficiency may be reduced.

[0092]

[0093] As described above, in the step of drawing the filament at a temperature of 70°C to 140°C in a heating ejector, the temperature of the heating ejector may be controlled by a convection method. This can be implemented when the difference in internal diameter between the inlet (101) and the outlet (102) of the ejector is satisfactorily 2 mm or more, and when the temperature of the heating ejector is controlled by a convection method, not only is the drawing efficiency of the filament increased, but also the low uniformity and excellent reproducibility of the filament finally manufactured can be implemented.

[0094]

[0095] The method for manufacturing a spunbond nonwoven fabric of the above embodiment may further include a step of drawing the filament at a temperature of 70°C to 140°C in a heating ejector; and then a step of colliding the filament with a metal member (7) to obtain a filament drawn by frictional electrification.

[0096]

[0097] In one embodiment, the first polyester filament may have a fineness of 1.21 denier or less.

[0098] Specifically, the first polyester filament may have a fineness of 1.0 denier to 1.21 denier, or 1.1 denier to 1.21 denier, or 1.11 to 1.21 denier.

[0099] The method for measuring the above fineness is not particularly limited, but can be measured using a fineness measuring device according to ASTM D 1577, for example.

[0100] As the first polyester filament satisfies the fineness range described above, the spunbond nonwoven fabric finally manufactured can realize excellent post-processing properties in post-processing such as impregnation, coating, dyeing, grinding, and laminating.

[0101]

[0102] Additionally, the first polyester filament may have a strength of 4.0 gf / de or more.

[0103] Specifically, the first polyester filament may have a strength of 4.0 gf / de to 4.5 gf / de, 4.0 gf / de to 4.4 gf / de, 4.05 gf / de to 4.4 gf / de, or 4.09 gf / de to 4.4 gf / de.

[0104] The method for measuring the above strength is not particularly limited, but can be measured using a universal tensile tester according to ASTM D3822, for example.

[0105] As the first polyester filament satisfies the strength range described above, the spunbond nonwoven fabric finally manufactured can realize excellent post-processing properties in post-processing such as impregnation, coating, dyeing, grinding, and laminating.

[0106]

[0107] The spunbond nonwoven fabric manufactured above can be used as a filter or protective clothing, etc.

[0108] The thickness of the above spunbond nonwoven fabric is not particularly limited, and may have a thickness of, for example, 100 μm to 800 μm.

[0109] The above filter may use the spunbond nonwoven fabric as a media, or may use the spunbond nonwoven fabric as a support material and additionally include a media.

[0110] The above-mentioned filter means a part capable of separating a specific substance, and the substance to be separated is not particularly limited, and may include, for example, foreign substances, particles, fine dust, liquid, bacteria, viruses, light, sound waves, radio waves, etc.

[0111] The products or fields in which the above filter is used are not particularly limited, and for example, it can be used in water purifiers, air conditioners, air purifiers, vacuum cleaners, gas masks, air filters, various oil filters for automobiles or airplanes, wastewater filters, semiconductor chemical filters, factory water purification filters, gas separation filters, gas separation membranes, blood dialysis filters, masks, etc.

[0112]

[0113] According to the present invention, a method for manufacturing a spunbond nonwoven fabric capable of implementing excellent post-processing properties is provided by using filaments that simultaneously have excellent strength and fineness.

[0114]

[0115] Figure 1 is a perspective view of a spunbond nonwoven fabric manufacturing device used in the method for manufacturing a spunbond nonwoven fabric of the present invention.

[0116] Figure 2 is a perspective view of a heating ejector used in the method for manufacturing a spunbond nonwoven fabric of the present invention.

[0117] Hereinafter, preferred embodiments are presented to aid understanding of the invention. However, the following examples are intended only to illustrate the invention and are not intended to limit the invention to these embodiments.

[0118]

[0119] Example 1

[0120] Polyethylene terephthalate (Re-PET; first polyester) having an intrinsic viscosity of 0.65 dl / g and a melting point of 255°C and copolyester (Co-PET; second polyester) having an intrinsic viscosity of 0.73 dl / g and a melting point of 230°C were each melted using a continuous extruder at 280°C.

[0121] The above first polyester melt was spun through a spinneret equipped with a spinneret having a circular cross-sectional discharge hole. The filament spun through the spinneret was solidified by cooling air, and then the filament was stretched using a heating ejector located 1450 mm from the bottom of the spinneret to form a first polyester filament.

[0122] At this time, the heater temperature of the heating ejector was 80 ℃, the elongation pressure was 4.0 kgf / cm2, and the spinning speed was 5000 m / min. The heating ejector is a 310 mm long ejector (ejector inlet inner diameter: 10 mm, outlet inner diameter: 13 mm) in which a heater is combined, and the distance from the inlet of the ejector to the center of the heater is 65 mm.

[0123] The second polyester melt was spun through a nozzle having a circular cross-section discharge hole to form a second polyester filament having a fineness of 1 to 2 denier.

[0124] The first polyester filament and the second polyester filament were mixed in a weight ratio of 80:20 (weight %) and laminated on a continuously moving net conveyor to form a fiber web.

[0125]

[0126] The obtained filaments were laminated on a continuously moving net conveyor to form a fiber web. The fiber web was passed through a smooth roller and an embossing roller maintained at 200°C and 35 N / mm to produce a spunbond nonwoven fabric.

[0127]

[0128] Example 2

[0129] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the heater temperature of the heating ejector was adjusted to 100°C.

[0130]

[0131] Example 3

[0132] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the heater temperature of the heating ejector was adjusted to 120°C.

[0133]

[0134] Example 4

[0135] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the weight ratio of the first polyester filament and the second polyester filament was mixed to be 85:15 (weight %).

[0136]

[0137] Example 5

[0138] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the weight ratio of the first polyester filament and the second polyester filament was mixed to be 65:35 (weight %).

[0139]

[0140] Comparative Example 1

[0141] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that an ejector without a heater was used instead of the above-mentioned heating ejector.

[0142]

[0143] Comparative Example 2

[0144] Instead of the above heating ejector, an ejector without a heater is used, and the elongation pressure is 4.5 kgf / cm 2 A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the temperature was adjusted to .

[0145]

[0146] Comparative Example 3

[0147] Instead of the above heating ejector, an ejector without a heater is used, and the elongation pressure is 5.0 kgf / cm 2 A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the temperature was adjusted to .

[0148]

[0149] Comparative Example 4

[0150] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the heating ejector was not heated.

[0151]

[0152] Comparative Example 5

[0153] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the heater temperature of the heating ejector was adjusted to 60°C.

[0154]

[0155] Comparative Example 6

[0156] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the heater temperature of the heating ejector was adjusted to 150°C.

[0157]

[0158] Comparative Example 7

[0159] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that a heating ejector was used in which the distance from the inlet of the ejector to the center of the heater was 200 mm.

[0160]

[0161] Comparative Example 8

[0162] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that a heating ejector having an ejector inlet inner diameter and an outlet inner diameter of 10 mm was used.

[0163]

[0164] Radiation Pack Pressure (Psi) Example 11,500 Example 21,500 Example 31,500 Example 41,500 Example 51,500 Comparative Example 11,500 Comparative Example 21,500 Comparative Example 31,500 Comparative Example 41,500 Comparative Example 51,500 Comparative Example 61,500 Comparative Example 71,500 Comparative Example 81,500

[0165] Exam example

[0166] (1) Island (de')

[0167]

[0168] The fineness of the first polyester filament was measured using a fineness tester (manufacturer: LENZING., model number: VIBROSKOP 400) based on the ASTM D 1577 test method. The fineness of a single filament is calculated from the fundamental resonance frequency and is measured by vibrating the fiber 7 to 9 cm under a tensile condition with varying vibration. The measured sample was measured 20 times, and the average value was used to indicate the fineness of the filament.

[0169]

[0170] (2) Strength (gf / de')

[0171] According to ASTM D3822, a strain-stress curve was obtained for the first polyester filament under the conditions of 25.4 mm in length and 2 mm / min using a universal tensile testing machine (manufacturer: Instron Engineering Corp., model number: Universal Testing Machine 5567A).

[0172] The strength (gf / de') was obtained from the stress and elongation at the breaking point, the initial elastic modulus (gf / de') was obtained from the tangent line that gives the maximum slope near the origin of the above curve, and the breaking elongation (%) was obtained. These measured values ​​were expressed as the average values ​​after measuring 20 samples of each target filament.

[0173]

[0174] (3) Uniformity (CV%)

[0175] The fineness of 20 first polyester filaments was measured using a fineness tester (manufacturer: LENZING., model number: VIBROSKOP 400) based on the ASTM D 1577 test method. The fineness of one filament was calculated from the fundamental resonance frequency and was measured by vibrating the fiber 7 to 9 cm under a tensile condition with varying vibration.

[0176] The standard deviation and average fineness of the measured fineness values ​​were calculated, and then the uniformity was calculated using the following formula.

[0177] [Mathematical formula]

[0178] Uniformity (CV%) = Standard deviation of fineness / Average fineness *100.

[0179]

[0180] Classification Fineness (de') Strength (gf / de') Breaking Elongation (%) Initial Elasticity (gf / de') Uniformity (CV%) Example 11.1 14.1 26 5.4 7 2.4 7 6.19 Example 21.1 9 4.4 0 7 4.7 6 8.2 7 8.63 Example 31.2 14.0 9 7 0.9 7 1.3 2 9.19 Example 41.2 04.6 26 7.8 7 3.1 9 7.74 Example 51.1 5 4.4 26 9.3 7 0.2 8 6.65 Comparative Example 11.2 23.8 0 66.5 7 9.5 0 9.59 Comparative Example 2 1.254.0073.578.277.09Comparative Example 31.424.1155.281.058.65Comparative Example 41.223.6785.051.6913.1Comparative Example 51.153.8765.885.454.63Comparative Example 61.033.7553.4141.176.56Comparative Example 71.723.2685.246.515.60Comparative Example 81.613.6179.156.3412.90

[0181] As shown in Tables 1 and 2 above, the spunbond nonwoven fabrics of the examples contained first polyester filaments having a fineness of 1.21 denier or less, and thus exhibited low uniformity while exhibiting a strength of 4.09 gf / de' or more, confirming that high strength and fineness were simultaneously achieved.

[0182] It was confirmed that the spunbond nonwoven fabrics of Comparative Examples 1 to 3 had a poor fineness of the first polyester filament of 1.22 denier or more due to the non-use of a heating ejector.

[0183] It was confirmed that the spunbond nonwoven fabric of Comparative Example 4 had lower fineness and strength and a greater uniformity compared to the example.

[0184] It was confirmed that the spunbond nonwoven fabrics of Comparative Examples 5 and 6 had poor strengths of 3.75 gf / de' to 3.87 gf / de' depending on whether the temperature of the heating ejector was 60 ℃ or 150 ℃.

[0185] It was confirmed that the spunbond nonwoven fabric of Comparative Example 7 had a decrease in fineness and strength as the heater of the heating ejector was positioned closer to the exit of the ejector.

[0186] It was confirmed that the spunbond nonwoven fabric of Comparative Example 8 had reduced fineness and strength and a large uniformity as the inner diameter of the ejector inlet and the inner diameter of the ejector outlet of the heating ejector were the same.

[0187]

[0188] Although the present invention has been described above through limited embodiments, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical idea of ​​the present invention and the equivalent scope of the patent claims to be described below by a person having ordinary skill in the art to which the present invention pertains.

[0189]

[0190] [Explanation of symbols]

[0191] 1: Radiation pack

[0192] 2: Radiated filament

[0193] 6: Pipe

[0194] 7: Metal parts

[0195] 100: Ejector

[0196] 101: Ejector inlet

[0197] 102: Ejector exit

[0198] 103: Heater

[0199] 200: Distance from the inlet of the ejector to the center of the heater

Claims

1. A step of manufacturing a filament by melting and spinning a thermoplastic resin; A step of drawing the above filament at a temperature of 70°C to 140°C in a heating ejector; A step of forming a fiber web by laminating the above-mentioned extended filaments; and A step of forming a spunbond nonwoven fabric by heat treating the above fiber web under pressure; The above heating ejector comprises an ejector and a heater coupled to the ejector, A method for manufacturing a spunbond nonwoven fabric, wherein the distance from the inlet of the ejector to the center of the heater is 10 mm or more and 100 mm or less.

2. In paragraph 1, A method for manufacturing a spunbond nonwoven fabric, wherein the difference in internal diameter between the inlet and outlet of the ejector is 2 mm or more.

3. In paragraph 1, A method for manufacturing a spunbond nonwoven fabric, wherein the ratio of the distance (200) from the inlet (101) of the ejector to the center of the heater (103) to the length of the ejector is 0.05 or more and 0.4 or less.

4. In paragraph 1, In the step of drawing the above filament at a temperature of 70℃ to 140℃ in a heating ejector; A method for manufacturing a spunbond nonwoven fabric, wherein the temperature of the above heating ejector is controlled by convection.

5. In paragraph 1, The step of manufacturing a filament by melting and spinning the thermoplastic resin is A step of manufacturing a first filament by melting and spinning a type of thermoplastic resin, or A method for producing a spunbond nonwoven fabric, comprising the step of producing two or more types of filaments by respectively melt-spinning two or more types of thermoplastic resins having different melting points.

6. In paragraph 5, A step of producing a first polyester filament by melt spinning a first polyester having a melting point of 250°C or higher; A step of drawing the first polyester filament at a temperature of 70°C to 140°C in a heating ejector; A step of forming a fiber web by laminating the first polyester filament and the second polyester filament that have been extended above; and A step of forming a spunbond nonwoven fabric by heat treating the above fiber web under pressure; comprising; Method for manufacturing spunbond nonwoven fabric.

7. In paragraph 6, The above first polyester filament has a melting point of 250°C or higher, A method for producing a spunbond nonwoven fabric, wherein the second polyester filament has a melting point of 160° C. to 235° C.

8. In paragraph 6, A method for producing a spunbond nonwoven fabric, wherein the fiber web comprises the first polyester filaments and the second polyester filaments in a weight ratio of 65:35 to 85:

15.

9. In paragraph 1, A step of drawing the above filament at a temperature of 70°C to 140°C in a heating ejector; thereafter, A method for manufacturing a spunbond nonwoven fabric, further comprising the step of obtaining a filament elongated by frictional electrification by colliding the filament with a metal member.

10. In paragraph 6, A method for manufacturing a spunbond nonwoven fabric, wherein the first polyester filament has a fineness of 1.21 denier or less.

11. In paragraph 6, A method for manufacturing a spunbond nonwoven fabric, wherein the first polyester filament has a strength of 4.0 gf / de or more.

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