Spunbond non-woven fabric and method for preparing same

Abstract

The present invention relates to a spunbond non-woven fabric and a method for preparing same. According to the present invention, provided are: a spunbond non-woven fabric that has a bonding area of 0.20 mm2 to 0.60 mm2 and can thus achieve excellent filtration performance and air permeability; and a method for preparing same.

Description

Spunbond nonwoven fabric and method for manufacturing the same

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0193586, filed December 27, 2023, and Korean Patent Application No. 10-2024-0156517, filed November 6, 2024, the entire contents of which are incorporated herein by reference.

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

[0003]

[0004] A filter is a material or device that creates a pressure difference on both sides of a partition through which a gas or liquid containing another phase passes to separate the other phase from the gas or liquid.

[0005] Nonwoven fabrics are typically used for filters. In particular, spunbond nonwoven fabrics are used in various industrial fields, including filters, due to their high productivity and excellent mechanical properties.

[0006] The performance of nonwoven fabrics for filters can vary depending on several factors that make up the nonwoven fabric. For example, the performance of nonwoven fabrics for filters can vary depending on factors such as the thickness, weight per unit area, and the fineness of the filaments that make up the nonwoven fabric.

[0007] Normally, nonwoven fabrics for filters are required to have high strength and stiffness to withstand the load generated during filtration.

[0008] The strength of nonwoven fabric increases as the weight per unit area and thickness of the nonwoven fabric increase, but this not only increases the cost of the nonwoven fabric but also causes the problem of wasting space in the filter.

[0009] Focusing on filtration efficiency in nonwoven filter fabrics tends to increase pressure loss, leading to reduced air permeability and liquid permeability, and consequently, a shortened service life. Conversely, focusing on air permeability and liquid permeability in nonwoven filter fabrics tends to extend service life, but also decrease filtration efficiency.

[0010] In addition, when spunbond nonwoven fabric is bonded with an embossing roller, bonding occurs at specific areas rather than the entire fiber-to-fiber bonding that constitutes the nonwoven fabric. At this time, depending on the bonded area and area ratio, the strength and shape retention of the nonwoven fabric may decrease, resulting in a problem of reduced pleat processability.

[0011]

[0012] The present invention provides a spunbond nonwoven fabric having excellent filtration performance and breathability, a method for manufacturing the same, and a filter.

[0013]

[0014] In this specification, a fiber web comprising a first polyester filament having a melting point of 250°C or higher and a second polyester filament having a melting point of 160°C to 235°C is provided, and a 250 cm according to the standard test method of ASTM D737-18(2023) 3 / cm 2 / sec or more, and the bonding area of ​​the embossing is 0.20 mm 2 0.60 mm 2 In, spunbond nonwoven fabric is provided.

[0015] In addition, the present specification provides a method for manufacturing a spunbond nonwoven fabric, including the steps of: melt spinning a thermoplastic resin to manufacture filaments; stacking the filaments on a net conveyor to form a fiber web; and embossing one surface of the fiber web using an embossing roller while fixing the web; wherein the fiber web includes 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 mixed, and the spunbond nonwoven fabric has a 250 cm according to the standard test method of ASTM D737-18(2023). 3 / cm 2 / sec or more, and the bonding area of ​​the spunbond nonwoven fabric is 0.20 mm 2 0.60 mm 2 A method for manufacturing a spunbond nonwoven fabric is provided.

[0016] Also provided herein is a filter including the spunbond nonwoven fabric.

[0017] Hereinafter, the spunbond nonwoven fabric, the manufacturing method thereof, and the filter according to the implementation examples of the present invention will be described in more detail.

[0018]

[0019] Unless explicitly stated otherwise in this specification, terminology is used only to describe specific embodiments and is not intended to limit the invention.

[0020] As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise.

[0021] 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.

[0022] 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.

[0023] 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.

[0024]

[0025]

[0026] According to one embodiment of the invention, a fiber web comprising 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., and having a 250 cm according to the standard test method of ASTM D737-18(2023) 3 / cm 2 / sec or more, and the bonding area of ​​the embossing is 0.20 mm 2 0.60 mm 2 In, spunbond nonwoven fabric is provided.

[0027] In general, the strength of nonwoven fabric increases as the weight per unit area and thickness of the nonwoven fabric increase, but this not only increases the cost of the nonwoven fabric but also wastes the space of the filter.

[0028] As a result of the research of the present inventors, it was confirmed that a spunbond nonwoven fabric satisfying the configurations as described above has a low weight per unit area and high stiffness, and thus can be suitably used as a filter medium and filter support, etc. The spunbond nonwoven fabric for filters has excellent stiffness as well as air permeability and quality index, and thus can contribute to improving filter performance in various fields.

[0029] The above spunbond nonwoven fabric can be preferably used as a filter medium and filter support in air purification systems and air conditioning (HVAC) systems.

[0030]

[0031] As a result of the research of the present inventors, the bonding area of ​​the embossing, like the spunbond nonwoven fabric of the above embodiment, is 0.20 mm 2 0.60 mm 2 By satisfying this, excellent filtration performance and breathability can be achieved.

[0032]

[0033] In one embodiment, the bonding area of ​​the embossing of the spunbond nonwoven fabric is 0.20 mm 2 0.60 mm 2 can satisfy.

[0034] As described above, the bonding area of ​​the embossing in the spunbond nonwoven fabric of the above embodiment is 0.20 mm 2 0.60 mm 2 By satisfying this, excellent filtration performance and breathability can be achieved.

[0035]

[0036] The bonding area of ​​the above embossing may refer to the maximum area of ​​a square inscribed in the non-bonding portion (2) in the smallest unit of bonding portion (1) surrounded by non-bonding portions on all sides, as shown in Fig. 1. For example, the bonding area of ​​the above embossing may refer to the area of ​​the bonding portion (1) of Fig. 1.

[0037] The bonding area of ​​the above embossing can be implemented by adjusting the protrusion size of the embossing roller used in manufacturing spunbond nonwoven fabric.

[0038] Specifically, the bonding area of ​​the embossing of the above spunbond nonwoven fabric is 0.20 mm 2 0.60 mm 2 , 0.30 mm 2 0.60 mm 2 , or 0.30 mm 2 0.56 mm in diameter 2 can satisfy.

[0039] If the bonding area of ​​the embossing of the above-mentioned spunbond nonwoven fabric is excessively reduced, the thermocompression bonding in the thickness direction will be insufficient even after bonding, and not only will the problem of delamination occur in the central part of the thickness, but also the leakage of fine particles into the delamination area may occur. In addition, the delamination area may become fluffy, making it difficult for dust to escape, resulting in a decrease in filtration performance, making it difficult to apply the fabric to a filter.

[0040] In addition, if the bonding area of ​​the embossing of the above-mentioned spunbond nonwoven fabric increases excessively, the bonding area may be filmed by thermal fusion, thereby reducing the pores and reducing the air permeability and filtration performance due to the area.

[0041]

[0042] In addition, the bonding area ratio of the above spunbond nonwoven fabric can be satisfied to be 5% or more and 10% or less.

[0043] As the bonding area ratio of the spunbond nonwoven fabric of the above embodiment satisfies 5% or more and 10% or less, excellent filtration performance and breathability can be achieved.

[0044]

[0045] The above bonding area ratio may refer to a percentage obtained by dividing the area of ​​the bonding portion (1) by the sum of the areas of the bonding portion (1) and the non-bonding portion (2). In Fig. 1, the non-bonding portion (2) may refer to a hatched portion. Specifically, the bonding area ratio may be calculated by the following mathematical formula 1.

[0046] [Mathematical Formula 1]

[0047] Bonding area ratio = (bonding area) / (bonding area + non-bonding area) x 100.

[0048]

[0049] The above bonding area ratio can be achieved by adjusting the projection shape of the embossing roller used in manufacturing spunbond nonwoven fabric.

[0050] Specifically, the bonding area ratio of the spunbond nonwoven fabric can satisfy 5% or more and 10% or less, 6% or more and 10% or less, 6.5% or more and 10% or less, 5% or more and 9.6% or less, 6% or more and 9.6% or less, and 6.5% or more and 9.6% or less.

[0051] If the bonding area ratio of the above spunbond nonwoven fabric is excessively reduced, the thermocompression bonding properties in the thickness direction will be insufficient even after bonding, and not only will the problem of delamination occur in the central thickness portion, but also the leakage of fine particles into the delamination portion may occur. In addition, fluff may be generated in the delamination portion, making it difficult for dust to escape, resulting in a decrease in filtration performance and making it difficult to apply the fabric to a filter.

[0052] In addition, if the bonding area ratio of the above-mentioned spunbond nonwoven fabric increases excessively, the bonding portion may be formed into a film by thermal fusion, thereby reducing the pores and reducing the air permeability and filtration performance due to the portion.

[0053]

[0054] In one embodiment, the spunbond nonwoven fabric may include a fiber web comprising first polyester filaments having a melting point of greater than or equal to 250° C. and second polyester filaments having a melting point of from 160° C. to 235° C.

[0055]

[0056] The above fiber web may be a fiber web in which the spunbond nonwoven fabric is a blend of 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, or may include a core-in-sheath type long fiber including a core portion including first polyester filaments having a melting point of 250°C or higher and a sheath portion including second polyester filaments having a melting point of 160°C to 235°C.

[0057]

[0058] 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.

[0059] 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.

[0060]

[0061] 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.

[0062] 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.

[0063]

[0064] The core-in-sheath type long fiber has a form consisting of a core portion and a sheath portion that surrounds the outer surface of the core portion, and the core portion and the sheath portion may contain polymers having the same or different compositions.

[0065] Preferably, in order to secure the mechanical properties of the core-in-sheath type long fiber, the core portion may be made of a polyester having a relatively high melting point. In addition, in order to provide sufficient bonding and fixation to the fiber web including the core-in-sheath type long fiber, the sheath portion may be made of a polyester having a relatively low melting point.

[0066]

[0067] According to one embodiment, the fiber web may comprise the first polyester filaments and the second polyester filaments in a weight ratio of 75:25 to 85:15.

[0068] 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 at least 15 wt% 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 at most 25 wt%, or at most 20 wt%, based on the weight of the fiber web.

[0069] Specifically, the weight ratio of the first polyester filament and the second polyester filament in the fiber web may be 75:25 to 85:15, or 80:20 to 85:15.

[0070]

[0071] According to one embodiment, the first polyester filament comprises a circular cross-section filament.

[0072]

[0073] The above first polyester filament may have a fineness of 6.0 denier or more.

[0074] Specifically, the first polyester filament may have a fineness of 6.0 denier or more, 6.0 denier or more and 10.0 denier or less, 7.0 denier or more and 10.0 denier or less, 7.5 denier or more and 10.0 denier or less, 6.0 denier or more and 9.0 denier or less, 7.0 denier or more and 9.0 denier or less, 7.5 denier or more and 9.0 denier or less.

[0075]

[0076] In one embodiment, the second polyester filament may be a circular cross-section filament.

[0077] 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 2 to 4 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.

[0078]

[0079] 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.

[0080]

[0081] 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.

[0082] And, 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.

[0083] If the spinning speed is too low, the extensibility may be reduced, the crystallinity of the filament may be reduced, and the strength and strength of the nonwoven fabric may be reduced. If the spinning speed is too fast, the cooling may be poor or the filaments may become entangled, which may reduce the uniformity of the nonwoven fabric.

[0084]

[0085] When the above fiber web is a fiber web in which the spunbond nonwoven fabric is a blended fiber web of 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, 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.

[0086]

[0087] In one embodiment, the spunbond nonwoven fabric has a content of 0.10 g / cm 3 0.20 g / cm 3 It is desirable to have an apparent density of .

[0088] The apparent density of the above spunbond nonwoven fabric is calculated by the following equation.

[0089] *Apparent density (g / cm) 3 ) = Weight per unit area (g / m 2 ) / Thickness (mm) / 1000

[0090] In order to ensure that the spunbond nonwoven fabric has an appropriate level of mechanical properties and density, the spunbond nonwoven fabric has a density of 0.10 g / cm 3 It is desirable to have an apparent density of 0.20 g / cm. However, if the apparent density is excessively high, the pressure loss may increase, which may lower the air permeability and shorten the service life. Therefore, the spunbond nonwoven fabric should have an apparent density of 0.20 g / cm. 3 It is desirable to have an apparent density below.

[0091] Specifically, the spunbond nonwoven fabric has a density of 0.10 g / cm 3 0.20 g / cm 3 , 0.14 g / cm 3 0.20 g / cm 3 , or 0.15 g / cm 30.20 g / cm 3 , or 0.16 g / cm 3 0.20 g / cm 3 , 0.10 g / cm 3 0.17 g / cm 3 , 0.14 g / cm 3 0.17 g / cm 3 , or 0.15 g / cm 3 0.17 g / cm 3 , or 0.16 g / cm 3 0.17 g / cm 3 It can have an apparent density of .

[0092]

[0093] The above spunbond nonwoven fabric can have high strength and air permeability while having a low weight per unit area by satisfying the above-described characteristics.

[0094]

[0095] In one embodiment, the spunbond nonwoven fabric has a stiffness of at least 240 mgf in at least one of the longitudinal and transverse directions. The spunbond nonwoven fabric may have a stiffness of at least 240 mgf in at least one of the longitudinal (MD) direction and the transverse (CD) direction. Preferably, the spunbond nonwoven fabric may have stiffnesses of at least 240 mgf in both the longitudinal and transverse directions.

[0096] Specifically, the spunbond nonwoven fabric may have a strength in at least one of the longitudinal and transverse directions of 240 mgf or more and 400 mgf or less, 240 mgf or more and 380 mgf or less, 245 mgf or more and 400 mgf or less, or 245 mgf or more and 380 mgf or less.

[0097] To ensure filter performance, the spunbond nonwoven fabric preferably has a stiffness of 245 mgf or higher. However, if the stiffness is too high, the quality index of the spunbond nonwoven fabric may deteriorate. Therefore, the spunbond nonwoven fabric preferably has a stiffness of 400 mgf or lower.

[0098] The method for measuring the above-mentioned strength is not particularly limited, but can be measured using a strength tester according to the standard test method of JIS L 1913:2010, for example.

[0099]

[0100] In one embodiment, the spunbond nonwoven fabric has a density of 50 g / m 2 100 g / m 2 It has a weight per unit area of ​​.

[0101] In order to ensure that an appropriate level of mechanical properties can be secured, the weight per unit area of ​​the spunbond nonwoven fabric is 50 g / m 2 It is desirable that the strength of the nonwoven fabric be higher as the weight per unit area and thickness of the nonwoven fabric increase, but this not only increases the cost of the nonwoven fabric but also causes a problem of wasted space in the filter. Therefore, the weight per unit area of ​​the spunbond nonwoven fabric is 100 g / m 2 The following is desirable.

[0102] Specifically, the spunbond nonwoven fabric has a density of 50 g / m 2 100 g / m 2 , or 70 g / m 2 100 g / m 2 , or 75 g / m 2 100 g / m 2 , or 50 g / m 2 80 g / m 2 , or 70 g / m 2 80 g / m 2 , or 75 g / m 2 80 g / m 2It can have a weight per unit area of ​​.

[0103]

[0104] In one embodiment, the spunbond nonwoven fabric has a 250 cm according to the standard test method of ASTM D737-18 (2023). 3 / cm 2 / sec or more. Specifically, the spunbond nonwoven fabric has an air permeability of 250 cm 3 / cm 2 / sec or more, or 250 to 400 cm 3 / cm 2 / sec, or 280 to 400 cm 3 / cm 2 / sec, or 250 to 380 cm 3 / cm 2 / sec, or 253 to 380 cm 3 / cm 2 / sec can have an air permeability of .

[0105]

[0106] The method for measuring the above air permeability is not particularly limited, but can be measured using an air permeability meter according to the standard test method of ASTM D737-18 (2023), for example.

[0107]

[0108] According to another embodiment of the invention,

[0109] A step of manufacturing a filament by melting and spinning a thermoplastic resin;

[0110] A step of forming a fiber web by stacking the above filaments on a net conveyor; and

[0111] A method for manufacturing a spunbond nonwoven fabric, comprising the step of fixing the web while embossing one side of the fiber web using an embossing roller;

[0112] The fiber web comprises a fiber web comprising 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,

[0113] The above spunbond nonwoven fabric is 250 cm according to the standard test method of ASTM D737-18 (2023). 3 / cm 2 / sec or more air permeability,

[0114] The bonding area of ​​the above spunbond nonwoven fabric is 0.20 mm 2 0.60 mm 2 A method for manufacturing a spunbond nonwoven fabric is provided.

[0115]

[0116] In the above manufacturing method, the respective characteristics of the first polyester filament and the second polyester filament are as described above.

[0117]

[0118] According to one embodiment, the first polyester filament and the second polyester filament may be mixed-spun, or the first polyester filament and the second polyester filament may be independently melted and compositely spun through a core-in-sheath type spinneret to form the core-in-sheath type long fiber.

[0119]

[0120] In the above spinning process, the spinning speed and tension can be adjusted to control the fineness of the filament.

[0121] For example, the step of manufacturing filaments by melt-spinning a thermoplastic resin is preferably 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 with 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.

[0122]

[0123] The above filaments are laminated on a continuously moving net conveyor by conventional opening methods such as electrostatic charging, collision plate, and air current diffusion to form a fiber web.

[0124]

[0125] Next, a step of fixing the web while embossing one side of the fiber web using an embossing roller is performed.

[0126] The above step is a step of thermally bonding the fibers forming the fiber web to obtain a spunbond nonwoven fabric. The thermal treatment can be performed at a temperature of 100°C to 250°C. For example, a spunbond nonwoven fabric with appropriate smoothness and thickness is obtained by passing the fiber web through a roller heated to approximately 200°C. Conventional devices such as a calendar roller, a smoothing roller, and an embossing roller can be used in the above step.

[0127]

[0128] The above-described bonding area and bonding area ratio can be achieved by adjusting the protrusion shape on the embossing roller.

[0129] The above embossing roller is divided into an upper roll having a surface engraved with a certain pattern or design and a lower roll having a flat shape without engraving. The temperatures of the upper and lower rolls can be set to an appropriate temperature depending on the melting point of the filament.

[0130]

[0131] Specifically, the temperature of the embossing roller can be adjusted according to the melting point of the second polyester filament having a low melting point, and can be adjusted to, for example, 120°C to 250°C. If the temperature of the embossing roller is excessively high, the fiber web may be thermally fused to the surface of the roll, making production impossible, or the shape of the fiber web may be destroyed due to melting of the fiber web caused by excessive heat energy application.

[0132] In addition, if the temperature of the embossing roller is excessively low, thermal bonding is not performed properly, making it difficult to maintain the shape of the embossing pattern and also reducing the physical properties of the nonwoven fabric.

[0133]

[0134] In the embossing process using the above embossing roller, the pressure (N / cm) between the upper and lower rolls 2 ) and at this time, the fiber web passing between the upper roll and the lower roll can be partially thermally bonded by the embossing projections included in the embossing roller.

[0135] The shape of the embossing pattern formed on the spunbond nonwoven fabric to be finally manufactured can be controlled depending on the shape of the embossing projections. The shape of the pattern is not particularly limited, but a square shape such as a rectangle, parallelogram, or diamond shape is preferable.

[0136]

[0137] As described above, the bonding area of ​​the embossing of the spunbond nonwoven fabric is 0.20 mm 2 0.60 mm 2 can satisfy.

[0138] As described above, the bonding area of ​​the embossing in the spunbond nonwoven fabric of the above embodiment is 0.20 mm 2 0.60 mm 2 By satisfying this, excellent filtration performance and breathability can be achieved.

[0139]

[0140] The bonding area of ​​the above embossing may refer to the maximum area of ​​a square inscribed in the non-bonding portion (2) in the smallest unit of bonding portion (1) surrounded by non-bonding portions on all sides as shown in Fig. 1. The bonding area of ​​the above embossing may be implemented by adjusting the protrusion size of the embossing roller used in the production of spunbond nonwoven fabric.

[0141] Specifically, the bonding area of ​​the embossing of the above spunbond nonwoven fabric is 0.20 mm 2 0.60 mm 2 , 0.30 mm 2 0.60 mm 2 , or 0.30 mm 2 0.56 mm in diameter 2 can satisfy.

[0142] If the bonding area of ​​the embossing of the above-mentioned spunbond nonwoven fabric is excessively reduced, the thermocompression bonding in the thickness direction will be insufficient even after bonding, and not only will the problem of delamination occur in the central part of the thickness, but also the leakage of fine particles into the delamination area may occur. In addition, the delamination area may become fluffy, making it difficult for dust to escape, resulting in a decrease in filtration performance, making it difficult to apply the fabric to a filter.

[0143] In addition, if the bonding area of ​​the embossing of the above-mentioned spunbond nonwoven fabric increases excessively, the bonding area may be filmed by thermal fusion, thereby reducing the pores and reducing the air permeability and filtration performance due to the area.

[0144] In the step of embossing using the above embossing roller, the speed of the embossing roller can be adjusted to 5 m / min or more and 20 m / min or less.

[0145] If the speed of the embossing roller is excessively slow, the air permeability may decrease or the differential pressure may increase due to partial film formation caused by over-bonding of the fiber web passing through the embossing roller.

[0146] Additionally, if the speed of the embossing roller is too fast, the embossing bonding may be formed unevenly.

[0147]

[0148] According to another embodiment of the invention, a filter comprising the spunbond nonwoven fabric described above may be provided.

[0149] The above filter may use the spunbond nonwoven fabric as a media, or may use the spunbond nonwoven fabric as a support and additionally include a media.

[0150] The thickness of the above spunbond nonwoven fabric is not particularly limited, and may have a thickness of, for example, 0.1 mm to 1 mm.

[0151] Specifically, when the spunbond nonwoven fabric is used as a media, it may have a thickness of 0.3 mm to 1 mm, and when the spunbond nonwoven fabric is used as a support, it may have a thickness of 0.1 mm to 0.8 mm.

[0152] 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.

[0153] 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.

[0154]

[0155] According to the present invention, a spunbond nonwoven fabric, a method for manufacturing a spunbond, and a filter that implement excellent filtration performance and breathability are provided.

[0156]

[0157] Figure 1 is a plan view showing the bonded and non-bonded portions of a spunbond nonwoven fabric.

[0158]

[0159] 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.

[0160]

[0161] Example 1

[0162] Polyethylene terephthalate (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 225°C were each melted using a continuous extruder at 280°C.

[0163] The first polyester melt was spun through a spinneret equipped with a nozzle having a circular cross-sectional discharge hole to form a first polyester filament having a fineness as described in Table 1 below.

[0164] After the continuous filaments radiated through the above-mentioned radiation pack were solidified by cooling air, they were drawn using a drawing device at a spinning speed of approximately 5,000 m / min, thereby forming a first polyester filament with an average fineness of 8.5 denier.

[0165] 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 3 denier.

[0166]

[0167] The first polyester filament and the second polyester filament were mixed in a weight ratio of 85:15 (weight %) and laminated on a continuously moving net conveyor to form a fiber web.

[0168]

[0169] The obtained filaments were stacked on a continuously moving net conveyor to form a fiber web. The fiber web was formed at 240°C and 200 N / cm. 2 Smooth roller and embossing roller that maintains (embossing area: 0.30 mm) 2 , embossing area ratio: 6.7%, temperature: 240℃, speed: 14.8 m / min) to manufacture a spunbond nonwoven fabric.

[0170]

[0171] Example 2

[0172] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that a copolymerized polyester (Co-PET; a second polyester) having a melting point of 212°C was used as the second polyester, and the temperatures of the smooth roller and the embossing roller were maintained at 220°C.

[0173]

[0174] Example 3

[0175] The melts of the first and second polyesters were continuously spun through a spinneret equipped with a core-in-sheath type spinneret to continuously obtain core-in-sheath type filaments having a core portion made of the first polyester and a sheath portion made of the second polyester. A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the core-in-sheath type filaments were used and the temperatures of the smooth roller and the embossing roller were maintained at 200°C.

[0176]

[0177] Example 4

[0178] Embossing area of ​​the embossing roller is 0.56 mm 2 A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the embossing area ratio was adjusted to 9.6%.

[0179]

[0180] Example 5

[0181] 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 adjusted to 80:20 (weight %).

[0182]

[0183] Example 6

[0184] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the average fineness of the first polyester filament was adjusted to 7.5 denier.

[0185]

[0186] Example 7

[0187] 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 adjusted to 75:25 (weight %).

[0188]

[0189] Comparative Example 1

[0190] A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the average fineness of the first polyester filament was adjusted to 5.4 denier.

[0191]

[0192] Comparative Example 2

[0193] A spunbond nonwoven fabric was manufactured in the same manner as in Example 3, except that the average fineness of the first polyester filament was adjusted to 5.4 denier.

[0194]

[0195] Comparative Example 3

[0196] 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 adjusted to 70:30 (weight %).

[0197]

[0198] Comparative Example 4

[0199] The average fineness of the above first polyester filament is adjusted to 5.4 denier, and the embossing area of ​​the embossing roller is 0.56 mm 2 A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the embossing area ratio was adjusted to 9.6%.

[0200]

[0201] Comparative Example 5

[0202] The average fineness of the above first polyester filament is adjusted to 5.4 denier, and the embossing area of ​​the embossing roller is 0.16 mm 2 A spunbond nonwoven fabric was manufactured in the same manner as in Example 1, except that the embossing area ratio was adjusted to 9.6% and the temperatures of the smooth roller and embossing roller were maintained at 220°C.

[0203]

[0204] Classification Filament Embossing Nonwoven Spinning Type 1 Filament Fineness (De') Composition Ratio 2nd Filament Melting Point (℃) Bonding Area (mm) 2 ) Bonding area ratio (%) Basis weight (g / m) 2 ) Example 1 Mixed fiber 8.585 / 152250.306.780 Example 2 Mixed fiber 8.585 / 152120.306.780 Example 3 Core-in-sheath type 8.585 / 152250.306.780 Example 4 Mixed fiber 8.585 / 152250.569.680 Example 5 Mixed fiber 8.580 / 202250.306.780 Example 6 Mixed fiber 7.585 / 152250.306.78 0 Example 7 Mixed fiber 8.575 / 252 250.306.780 Comparative Example 1 Mixed fiber 5.485 / 152 250.306.780 Comparative Example 2 Core-in-sheath type 5.485 / 152 250.306.780 Comparative Example 3 Mixed fiber 8.570 / 302 250.306.7- Comparative Example 4 Mixed fiber 5.485 / 152 250.569.680 Comparative Example 5 Mixed fiber 5.485 / 152 120.169.680

[0205] Exam example

[0206] (1) Island (de')

[0207] The fineness of the 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. The fiber was vibrated 7 to 9 cm under a tensile state with varying vibration, and the average value of 10 measurements was used to represent the fineness of the filament.

[0208]

[0209] (2) Lecture (mgf)

[0210] Specimens (1 inch x 2.5 inches) of spunbond nonwoven fabrics according to Examples and Comparative Examples were prepared. The stiffness (mgf) of the specimens in the longitudinal (MD) and transverse (CD) directions was measured using a stiffness tester (Gurley type stiffness tester, 4171D) according to the standard test method of JIS L 1913:2010. The stiffness was expressed as the average value after 20 measurements.

[0211]

[0212] (3) Air permeability (cm) 3 / cm 2 / sec)

[0213] The air permeability of spunbond nonwoven fabrics was measured under a pressure of 125 Pa using an air permeability meter (FX 3300 LabAir IV, TEXTEST INSTRUMENTS) according to the standard test method of ASTM D737-18 (2023).

[0214]

[0215] (4) Evaluation of operability and quality

[0216] If defects occur on the nonwoven fabric due to clumping, cutting, or dropping of filaments during the manufacturing process of spunbond nonwoven fabric, the workability and quality are evaluated as ‘poor.’

[0217]

[0218]

[0219] Apparent density (g / cm) 3 )Air permeability (ccs, cm) 3 / cm 2 / sec)Lecture degree (mgf)Quality evaluation MDCDExample 10.160298301286GoodExample 20.167337270273GoodExample 30.167287273293GoodExample 40.170377263277GoodExample 50.167331359333GoodExample 60.163253275245GoodExample 70.170345363341GoodComparativeExample 10.178199200178GoodComparativeExample 20.181205195189GoodComparativeExample 3----RadiationPoorComparativeExample 40.170243234235GoodComparativeExample 50.200168156164Good

[0220] Referring to Tables 1 and 2 above, the spunbond nonwoven fabrics of the examples have a strength of 245 mgf or more in both the longitudinal (MD) and transverse (CD) directions and a tensile strength of 250 cm 3 / cm 2 It showed an air permeability of more than / sec, and was confirmed to have good operability and quality.

[0221]

[0222] On the other hand, it was confirmed that the spunbond nonwoven fabric of the comparative example exhibited significantly lower stiffness and poorer air permeability compared to the examples.

[0223] In particular, in Comparative Example 3, as the content of the second polyester was too high, cooling and stretching could not be performed properly during the spinning process, and ultimately, a nonwoven fabric could not be manufactured.

[0224] 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.

[0225]

[0226] [Explanation of symbols]

[0227] 1: Bonding section

[0228] 2: Non-bonding part

Claims

A fiber web comprising first polyester filaments having a melting point of 1.250° C. or higher and second polyester filaments having a melting point of 160° C. to 235° C., 250 cm according to the standard test method of ASTM D737-18(2023) 3 / cm 2 / sec or more air permeability, The bonding area of ​​the embossing is 0.20 mm 2 0.60 mm in depth 2 In, spunbond nonwoven fabric.

2. In paragraph 1, A spunbond nonwoven fabric, wherein the bonding area ratio of the above spunbond nonwoven fabric is 5% or more and 10% or less.

3. In paragraph 1, A spunbond nonwoven fabric comprising the first polyester filaments and the second polyester filaments in a weight ratio of 75:25 to 85:

15.

4. In paragraph 1, A spunbond nonwoven fabric wherein the first polyester filament has a fineness of 6.0 denier or more.

5. In paragraph 1, A spunbond nonwoven fabric wherein the second polyester filament has a fineness of 1 to 5 denier.

6. In paragraph 1, The above spunbond nonwoven fabric is 0.10 g / cm 3 Within 0.20 g / cm 3 A spunbond nonwoven fabric having an apparent density of .

7. In paragraph 1, The above spunbond nonwoven fabric is 50 g / m 2 Within 100 g / m 2 A spunbond nonwoven fabric having a weight per unit area of:

8. In paragraph 1, The above spunbond nonwoven fabric has a strength of at least 240 mgf in at least one of the longitudinal and transverse directions. Spunbond nonwoven fabric.

9. A step of manufacturing a filament by melting and spinning a thermoplastic resin; A step of forming a fiber web by stacking the above filaments on a net conveyor; and A method for manufacturing a spunbond nonwoven fabric, comprising: a step of fixing a web while embossing one side of the fiber web using an embossing roller; The above fiber web comprises a fiber web comprising 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., The above spunbond nonwoven fabric is 250 cm according to the standard test method of ASTM D737-18 (2023). 3 / cm 2 / sec or more air permeability, The bonding area of ​​the above spunbond nonwoven fabric is 0.20 mm 2 0.60 mm in depth 2 A method for manufacturing a spunbond nonwoven fabric.

10. In paragraph 9, A method for manufacturing a spunbond nonwoven fabric, wherein the bonding area ratio of the spunbond nonwoven fabric is 5% or more and 10% or less.

11. In paragraph 9, A method for manufacturing a spunbond nonwoven fabric, wherein in the step of fixing the web while embossing one side of the fiber web using an embossing roller, the temperature of the embossing roller is 120°C to 250°C.

12. In paragraph 9, A method for manufacturing a spunbond nonwoven fabric, wherein in the step of fixing the web while embossing one side of the fiber web using an embossing roller, the speed of the embossing roller is 5 m / min or more and 20 m / min or less.

13. In paragraph 9, 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 75:25 to 85:

15.

14. In paragraph 9, The above first polyester filament has a fineness of 6.0 denier or more, or A method for producing a spunbond nonwoven fabric, wherein the second polyester filament has a fineness of 1 to 5 denier.

15. A filter including the spunbond nonwoven fabric of paragraph 1.

Images