Spunbonded non-woven fabric with improved opening quality and no hazardous residue

Abstract

To provide a spunbonded non-woven fabric containing no hazardous residue and having improved opening quality, and a method and an apparatus for producing the same.SOLUTION: The method for producing the spunbonded non-woven fabric according to the present invention comprises the step of obtaining filaments that are opened by colliding the continuous filament bundles against a metal member containing bismuth (Bi) or bismuth alloy, causing triboelectrification to occur.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a spunbond nonwoven fabric that does not contain any residual harmful substances and has improved fiber opening quality, The present invention relates to a manufacturing method and a manufacturing apparatus for the same. [Background technology]

[0002] Generally, the manufacturing process of spunbond nonwoven fabrics includes spinning, cooling, stretching, web formation, bonding, and winding. The continuous spunbonding process is highly productive and economical. It has the following characteristics.

[0003] The manufacturing process of spunbond nonwoven fabric is divided into two stages: Dokan (Dokan) and Dokan (Dokan) due to the difference between the spinning process and the stretching process. can system and Reicofil system, and It is subdivided according to the filament opening technology used for fabrication.

[0004] The Lycofil system is a spinning pack with a rectangular structure. The molten polymer discharged from the sintering tube passes through a closed cooling / drawing section and is then drawn into a filament curtain. It is spun in the form of a curtain, and aerodynamic Separation by corona charge or corona charge method The Lycofil system provides high production volume and fast production speed. The advantage of nonwoven fabric is that the manufacturing cost is low. It is being applied to sanitary materials, protective clothing, and filters using olefin raw materials such as propylene. However, PET has been unable to enter the high value-added market due to its poor mechanical properties and appearance quality. There is difficulty in entering.

[0005] The Dokan system is a system in which the molten polymer is discharged from a circular spin pack and then released into the After passing through the cooling / drawing section, the fibers are formed into a filament bundle and then mechanically mechanical-force, electrostatic-force The web is formed by opening the fibers in a rge or hybrid manner. The woven fabric has excellent mechanical properties and a uniform appearance, making it suitable for high value-added products. However, the productivity is lower than that of the Lycofil system, so the manufacturing cost is high. It has a

[0006] Under the Dokan system, forced charging by corona discharge, friction material (e.g. metal) and Various fiber spreading methods have been developed, such as friction charging by collision of the fibers. Although the filament bundle spread is improved by this, the area density imbalance of the web (i.e., There is still a need to improve the uniformity of the weight per unit area of ​​the web.

[0007] On the other hand, the performance of the friction charging method is controlled according to the charging sequence of the friction material. For example, the friction (collision) between the polyester filament and the metal plate causes the polyester The friction causes the filaments to have a negative charge. The Coulomb repulsive force between the filaments The filaments are opened by a wire orce.

[0008] Lead (Pb) has traditionally been used as the metal plate material in the friction charging method. However, lead is brittle and easily wears away due to friction with the filament. In the triboelectric method, residual lead exists in spunbond nonwoven fabrics manufactured using lead as a friction material. It is possible.

[0009] Lead (Pb) is one of the six major hazardous substances listed in the European Union's (EU) Restriction of Hazardous Substances (RoHS) guidelines. It is one of the substances that has a potential risk of harm to the human body. Pb) has permissible limits for different uses in life science materials, and its use is therefore not recommended. This is the current situation. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has a negative charge donating ability equivalent to that of lead (Pb), but is not harmful to the human body. A method for producing a spunbond nonwoven fabric having improved fiber opening quality using a friction material is provided. do.

[0011] The present invention provides an apparatus for producing the spunbonded nonwoven fabric.

[0012] The present invention provides a spunbond nonwoven fabric that does not contain any residual harmful substances and has improved fiber opening quality. A woven fabric is provided. [Means for solving the problem]

[0013] According to one embodiment of the present invention, melt spinning a thermoplastic resin to obtain a continuous filament bundle; The continuous filament bundle is then heated to a temperature of 1000° C. for 15 minutes at 3 ... a step of causing the filaments to collide with a metal member to obtain filaments opened by frictional charging; The opened filaments are collected on a continuous conveyor net to form a fibrous web. The stage A method for producing a spunbond nonwoven fabric is provided, comprising:

[0014] According to another embodiment of the present invention, A plurality of nozzle units arranged and configured to eject a continuous filament bundle. Knit and The continuous filament bundle discharged by the nozzle unit collides with the an impingement unit adjacent each of the nozzle units at a position for impinging the nozzles; The filaments opened by frictional charging with the collision unit are collected and transported. A continuous conveyor net is also included. The collision unit is a metal member containing bismuth (Bi) or a bismuth alloy. Including faces, An apparatus for producing a spunbond nonwoven fabric is provided.

[0015] According to yet another embodiment of the present invention, a fibrous web including thermoplastic filaments; having a residual amount of bismuth (Bi) of 0.01 ppmw to 10.0 ppmw; A spunbond nonwoven fabric is provided.

[0016] The following describes a method for producing a spunbonded nonwoven fabric according to an embodiment of the present invention. The manufacturing apparatus and the spunbond nonwoven fabric manufactured using said apparatus are described in more detail below. Reveal.

[0017] Unless otherwise defined herein, all technical and scientific terms are used herein by reference to the present invention. The meaning of the term has the same meaning as that generally understood by a person skilled in the art. The terms used herein are merely for the purpose of describing specific embodiments and are not intended to limit the present invention. Then it is not intended.

[0018] As used herein, the singular forms "a," "an," and "the" refer to any or all of the following unless the context clearly indicates to the contrary. Plural forms are also included.

[0019] As used herein, "comprises" means any particular property, region, integer, step, operation, element, or combination of elements. and / or components, and other specific properties, regions, integers, steps, operations, elements, components The presence or addition of and / or groups is not excluded.

[0020] While the present invention may be modified in various ways and take various forms, specific embodiments have been illustrated. However, it is not intended to limit the invention to the particular forms disclosed. The present invention is not intended to be limited to the above-mentioned embodiments, and any modifications, equivalents or substitutes falling within the spirit and technical scope of the present invention are intended to be included therein. It should be understood that this includes substitutions.

[0021] In this specification, the terms "on", "at the top", "below", "to the side", etc. When describing the relative positions of two parts, such as Since no other part is used, one or more other parts can be located between the two parts.

[0022] In this specification, for example, "after", "next", "after", "before", etc. When describing a temporal context, the words "directly" or "immediately" are not used. The above may include cases where the signals are not consecutive.

[0023] As used herein, the term "at least one" means that one or more of the associated items can be presented. It should be understood that all combinations are included.

[0024] I. Manufacturing method of spunbond nonwoven fabric According to one embodiment of the invention, melt spinning a thermoplastic resin to obtain a continuous filament bundle; The continuous filament bundle is then heated to a temperature of 1000° C. for 15 minutes at 3 ... a step of causing the filaments to collide with a metal member to obtain filaments opened by frictional charging; The opened filaments are collected on a continuous conveyor net to form a fibrous web. The stage A method for producing a spunbond nonwoven fabric is provided, comprising:

[0025] Conventionally, the Docan system's fiber-spreading process involves filament bundles and lead sheets. It is controlled by the generation of electrostatic forces due to friction between the filaments, and the kinetic energy of the filaments drives the When the plate material wears down, trace amounts of lead remain in the nonwoven fabric.

[0026] However, unlike industrial materials, life science materials do not affect the oral cavity, respiratory tract, or skin. Residual lead may be exposed through the product, and this potential risk may make it difficult to enter the market. There was a difficulty.

[0027] However, as a result of the continued research of the present inventors, the spunbond nonwoven fabric by the Dokan system In the manufacture of the product, metal components containing bismuth (Bi) or bismuth alloys are applied to the friction material. In this case, it is possible to demonstrate the same level of negative charge donating ability as conventional lead (Pb) metal components. The result is a spunbond nonwoven fabric that contains no residual harmful substances and has improved fiber opening quality. It was confirmed that it can be produced.

[0028] FIG. 1 is a schematic diagram of a spunbond nonwoven fabric manufacturing apparatus according to one embodiment of the present invention. do.

[0029] First, (i) a step of melt-spinning a thermoplastic resin to obtain a continuous filament bundle is performed. It will be held.

[0030] The thermoplastic resin may be a resin that is generally used in the technical field to which the present invention pertains, but may also be a resin that has been specially restricted. It can be used without limit.

[0031] The thermoplastic resin has a melting point of 200° C. or more, which improves the mechanical properties of the filament. This may be advantageous in ensuring

[0032] Preferably, the thermoplastic resin is a polyester, a polyamide, a polyolefin, or The resin may be one or more resins selected from the group consisting of polyphenylene sulfide and polyphenylene sulfide.

[0033] Specifically, the thermoplastic resin is polyethylene terephthalate, polybutylene terephthalate, Polycyclohexane terephthalate, polyethylene naphthalate, nylon, Consists of polyethylene, polypropylene, polybutylene, and polyphenylene sulfide. The resin may be one or more resins selected from the group consisting of:

[0034] The thermoplastic resin is melted in a continuous extruder having a screw and a heater, and then fed to a spinneret. The filament bundle is formed by continuously discharging the filaments through a nozzle.

[0035] The continuous filament bundle is compressed and evacuated in the cylindrical pipe of the nozzle unit 10. The liquid is stretched by the air and the ejector and exhaled through the jet nozzle. It is served.

[0036] the denier of the filaments constituting the continuous filament bundle; and The cross-sectional shape is not particularly limited. As a non-limiting example, the filament may have a diameter of 1 to 10 nm. It can have any fineness and a circular or irregular cross section.

[0037] (ii) continuously converting the continuous filament bundle into a bismuth (Bi) or The filaments are opened by frictional charging by colliding them with a metal member containing a silicon alloy. A step is then carried out.

[0038] The step (ii) is discharged through a jet nozzle of the nozzle unit 10. The continuous filament bundle 11 is collided with the collision surface of the collision unit 20. The frictional charging is induced by the charge order between the material of the collision surface and the filament bundle. The filaments, which now have the same charge, are repulsed by the Coulomb repulsion between them. This is the stage where the ment is opened.

[0039] In the step (ii), the main factor determining the dispersion form and the spread quality of the filament bundle 11 is One of the important factors is the type of material that constitutes the collision surface of the collision unit 20.

[0040] Lead (Pb) has traditionally been used as the material forming the impact surface of the impact unit 20. However, trace amounts of lead that fell off due to friction with the filaments remained in the nonwoven fabric, Induces potential risk of harm to humans.

[0041] An approach based on solid-state physics For example, lead (Pb) is classified as follows: Lead (Pb) is 5×10 6 It has a conductivity of S / m. By doing so, it is electrically classified as a "conductor" among conductors, semiconductors and non-conductors. Pb) is -23.0×10 -6 cm 3 / mol(at 298K) magnetic susceptibility (magn It has magnetic susceptibility and is magnetically ferromagnetic, paramagnetic and Lead (Pb) is classified as a diamagnetic material, with a temperature of 600.61K (327 With a melting point of 1.46°C (621.43°F), it is thermally compatible with high and low temperature melts. Lead (Pb) is classified as a "low-temperature melt" among melts. The hardness (Hv) of a material determines whether it is mechanically hard or soft, i.e. "soft," and brittle. and is classified as "toughness" within toughness.

[0042] According to one embodiment of the invention, the continuous filament bundle 11 is made of bismuth (Bi) or is collided with a metal member containing a bismuth alloy.

[0043] Bismuth (Bi) is 7.7 x 10 5 By having a conductivity of S / m, it is considered an electrical conductor. ";-280.1×10 -6 cm 3 / mol(at 298K) By having magnetic susceptibility, Classified as "diamagnetic"; has a melting point of 544.7 K (271.5 °C, 520.7 °F) It is thermally classified as a "low melt" and has a Vickers hardness (Hv) of 11.55. This allows them to be mechanically classified as "soft" and "tough."

[0044] Bismuth (Bi) can exhibit the same level of negative charge donating ability as lead (Pb). It is also stronger and is compliant with the European Union's Restriction of Hazardous Substances (RoHS) directive. It does not belong to the hazardous substances.

[0045] Therefore, bismuth or a bismuth alloy is applied to the collision surface of the collision unit 20. By doing so, the spunbond nonwoven fabric does not contain any residual harmful substances and has improved fiber opening quality. can be obtained.

[0046] Preferably, a metal member made of bismuth is applied to the collision surface of the collision unit 20. It is possible.

[0047] Moreover, a metal member made of a bismuth alloy can be applied to the collision surface. The bismuth alloy contains 10% by weight or more of the bismuth alloy, or 0% or more by weight, alternatively 30% or more by weight, alternatively 40% or more by weight, alternatively 45% or more by weight The effect of the present invention can be exhibited by including bismuth in an amount of 50% by weight or more. In particular, the bismuth alloy may be 10% to 80% by weight, or 20% to 80% by weight, or 20% to 70% by weight 0% by weight, or 30% to 70% by weight, or 30% to 60% by weight, or is 40% by weight to 60% by weight, or 45% by weight to 60% by weight, or 45% by weight to 50% by weight It may contain 5% by weight of bismuth.

[0048] The bismuth alloy does not contain any other substances that are hazardous under the RoHS guidelines, except for bismuth. In addition, metals that do not impair the properties of bismuth are further included. For example, the bismuth alloy are copper (Cu), zinc (Zn), tin (Sn), aluminum (Al), molybdenum (M o), and titanium (Ti). As a non-limiting example, the bismuth alloy may be 50% by weight bismuth (Bi) and 50% by weight bismuth (Bi). The bismuth alloy may contain copper (Cu) in an amount of 100% by mass. The metal is selected in consideration of the physical properties of the metal and the physical properties to be imparted to the collision surface. It is possible to select.

[0049] According to one embodiment of the invention, the continuous filament bundle 11 is 4,000 m / min~6,000m / min, or 4,500m / min~6,000m / min or at a linear velocity of 4,500 m / min to 5,500 m / min, It can be poked.

[0050] The continuous filament bundle 11 is a continuous filament band Each nozzle sprays 2.0kg / hr to 8.0kg / hr, or 3. Mass from 0kg / hr to 8.0kg / hr, or 3.0kg / hr to 6.0kg / hr At the flow rate, it can impact the metal member.

[0051] The frictional electrification caused by the collision with the metal member is sufficiently generated, while maintaining the fiber spreading quality and To ensure runnability, the continuous filament bundle 11 is It is preferable that the powder impinges on the metal member within a range of a quantity flow rate range.

[0052] According to one embodiment of the invention, the triboelectrically opened filaments 22 are -3 500nC / sec~-500nC / sec, or -3400nC / sec~-60 Charge generation of 0nC / sec or -3400nC / sec to -700nC / sec (value measured by the Faraday cage method).

[0053] The filaments 22 opened by the frictional charging have a charge generation amount within the above range. The fibers are spread to a wide width and with excellent quality.

[0054] The amount of electric charge generated by the opened filaments 22 is determined by the collision with the metal member. The amount of electrostatic discharge that the filament has ostatic discharge, Faraday cage The temperature can be measured using the 100° C. (100° F.)

[0055] The Faraday cage is divided into an inner cage and an outer cage. The sieve is designed so that the filaments 22 that collide with the metal member and are opened are trapped. The outer cage, which is grounded, is placed so as to surround the entire surface of the inner cage. A digital coulomb meter is placed in contact with the inner cage. The time it takes for the charge difference with the external cage to reach -9,000 nC is measured by the digital coulomb The static electricity of the opened filaments was measured with a meter and normalized by time. The amount of electrical discharge can be obtained.

[0056] According to one embodiment of the present invention, the jet for ejecting the filament bundle in step (ii) is The nozzle is connected to the shaft of a step motor and rotates at -15±5° Nozzle rotation angle range of + / -15±5° and 3counter / sec~12counter The nozzle reciprocation speed in t / sec can be controlled.

[0057] (iii) continuously conveying the opened filaments 22 onto a continuous conveyor net 30; A step of converging to form a fibrous web 33 is then performed.

[0058] The filaments that have become negatively charged by the frictional electrification are The continuous conveyor net 30 made of metal is opened by the Coulomb repulsion between the wires. The negatively charged filaments are then transported to the grounded conveyor net. 30 by electrostatic forces to form a fibrous web 33.

[0059] According to one embodiment of the invention, the opened filaments 22 are The rotation angle range of the nozzle that sprays the dollar is -15±5° to +15±5°, and the forward and backward of the nozzle 500mm or more under the condition of return speed 3counter / sec~12counter / sec The fibers can be gathered onto the continuous conveyor net 30 at the above opening width.

[0060] In order to ensure excellent spreading quality, the spread width of the spread filaments 22 is 500 mm. Preferably, the spread width is 500 mm or more. 500mm~700mm, or 500mm~650mm, or 520~650m m may also be used.

[0061] Here, the spread width is the width of the spread filaments collected on the continuous conveyor net 30. The spread width means the maximum width based on the moving direction of the ment 22. The values ​​of the opened filaments obtained from the impact unit and the corresponding impact unit is the standard.

[0062] The fiber web is then bonded by thermal bonding or the like to form the spunbond fiber. A nonwoven fabric is obtained. The bonding is carried out using a calendar roll or an embossing roll. do.

[0063] II. Spunbond nonwoven fabric manufacturing equipment According to another embodiment of the invention, A plurality of nozzles configured and arranged to dispense a continuous filament bundle 11. Unit 10 and The continuous filament bundle 11 discharged by the nozzle unit 10 impingement units adjacent to each of the nozzle units 10 in position for impingement with 20 and The filaments 22 that are opened by frictional charging with the collision unit 20 are collected and and a continuous conveyor net 30 for transporting the The collision unit 20 is a metal member containing bismuth (Bi) or a bismuth alloy. Including the impact surface, An apparatus for producing a spunbond nonwoven fabric is provided.

[0064] The spunbond nonwoven fabric manufacturing apparatus is the same as that described in "I. Method for manufacturing spunbond nonwoven fabric" above. It is used to execute.

[0065] FIG. 1 is a schematic diagram of a spunbond nonwoven fabric manufacturing apparatus according to one embodiment of the present invention. do.

[0066] The spunbond nonwoven fabric manufacturing apparatus according to an embodiment of the invention is a continuous filament bundle. The nozzle unit 10 includes a plurality of nozzle units 10 arranged and configured to eject ink droplets 11.

[0067] The thermoplastic resin, which is the raw material, is extruded in a continuous extruder having a screw and a heater (not shown in FIG. 1). The filaments are melted in a nozzle and extruded continuously through a spinneret to produce a continuous filament. The nucleus forms a central bundle.

[0068] The nozzle unit 10 includes a cylindrical pipe connected to the spinneret, and and a jet nozzle formed on one side of the nozzle.

[0069] The continuous filament bundle is inserted into the cylindrical pipe of the nozzle unit 10. The jet nozzle is stretched by compressed air and an ejector. It is discharged through.

[0070] The jet nozzle is connected to a shaft of a step motor, Nozzle rotation angle range of -15±5°~+15±5° and 3counter / sec~ It is controlled by the nozzle reciprocating speed of 12 counters / sec.

[0071] The jet nozzle is configured to jet the continuous filament bundle 11 at a speed of 4,000 m / min to 6,000m / min, or 4,500m / min~6,000m / min, or It can be extruded at a linear velocity of 4,500 m / min to 5,500 m / min.

[0072] The continuous filament bundle 11 is a continuous filament band The flow rate per jet nozzle is 2.0kg / hr to 8.0kg / hr, or 3.0kg / hr~8.0kg / hr, or 3.0kg / hr~6.0kg / hr The air can collide with the metal member of the collision unit 20 at a mass flow rate of 1000 .mu.m.

[0073] The spunbond nonwoven fabric manufacturing apparatus according to the embodiment of the present invention is provided with the nozzle unit 10. at a position for collision with the continuous filament bundle 11 discharged from the Each of the nozzle units 10 includes an impingement unit 20 adjacent thereto.

[0074] The collision unit 20 is a metal member containing bismuth (Bi) or a bismuth alloy. The collision surface includes an impact surface that impacts the continuous filament in the impact unit 20. This refers to the side that directly conflicts with bundle 11.

[0075] Preferably, a metal member made of bismuth is applied to the collision surface of the collision unit 20. It is possible.

[0076] Also, a metal member made of a bismuth alloy can be applied to the collision surface. The bismuth alloy contains 10% by weight or more, or 20% by weight or more, based on the weight of the bismuth alloy. % by weight or more, alternatively 30% by weight or more, alternatively 40% by weight or more, alternatively 45% by weight or more The inclusion of bismuth in the composition is effective in achieving the above-mentioned effects of the present invention. Specifically, the bismuth alloy may be 10% to 80% by weight, alternatively 20% to 80% by weight, alternatively 20% to 70% by weight % by weight, alternatively 30% to 70% by weight, alternatively 30% to 60% by weight, alternatively 40% to 60% by weight, or 45% to 60% by weight, or 45% to 55% by weight It may contain bismuth at a concentration of about 100% by weight.

[0077] The bismuth alloy does not contain any hazardous substances other than bismuth under the RoHS guidelines. In addition, metals that do not impair the properties of bismuth are further included. For example, the bismuth alloy are copper (Cu), zinc (Zn), tin (Sn), aluminum (Al), molybdenum (M o), and titanium (Ti). As a non-limiting example, the bismuth alloy may be 50% by weight bismuth (Bi) and 50% by weight bismuth (Bi). % by weight of copper (Cu). The other metal is selected taking into consideration the physical properties of the metal and the physical properties to be imparted to the collision surface. It is selectable.

[0078] The collision unit 20 detects the continuous At the position for collision with the filament bundle 11, the filaments are opened by frictional charging. The lament 22 is set at an angle that allows it to be collected on a continuous conveyor net 30. It is possible.

[0079] The spunbond nonwoven fabric manufacturing apparatus according to the embodiment of the present invention is a friction unit with the collision unit 20. A continuous conveyor net 30 that collects and transports the filaments 22 that have been opened by charging. Includes.

[0080] The continuous conveyor net 30 is preferably grounded. The opened filaments 22 are negatively charged due to frictional charging with the mat 20. can be fixed on the continuous conveyor net 30 by electrostatic force. is preferred.

[0081] The continuous conveyor net 30 is formed by collecting the opened filaments 22. The fibrous web 33 thus formed is continuously transported.

[0082] In addition, the spunbond nonwoven fabric manufacturing apparatus according to the embodiment of the present invention further comprises: , and may include a bonding unit for adjusting and bonding to a predetermined thickness.

[0083] The bonding unit is used in the field of the present invention to bond nonwoven fabrics. It can have the usual configurations, such as calender rolls and embossing rolls.

[0084] III. Spunbond nonwoven fabric According to yet another embodiment of the invention, Obtained by the above-mentioned production method, a fibrous web including thermoplastic filaments; Having a residual amount of bismuth (Bi) of 0.01 ppmw to 10.0 ppmw; A spunbond nonwoven fabric is provided.

[0085] The spunbond nonwoven fabric is obtained by the above-mentioned "I. Method for producing spunbond nonwoven fabric". It may also be something that has been

[0086] The spunbond nonwoven fabric is produced by the above-mentioned "II. Spunbond nonwoven fabric production apparatus". It may be obtained using

[0087] According to an embodiment of the invention, the spunbond nonwoven fabric is a fiber comprising thermoplastic resin filaments. Includes maintenance web.

[0088] The thermoplastic resin filaments are obtained by using a thermoplastic resin.

[0089] The thermoplastic resin may be any resin commonly used in the technical field to which the present invention pertains, without any particular limitations. It can be used without any problems.

[0090] The thermoplastic resin has a melting point of 200° C. or more, which improves the mechanical properties of the filament. This may be advantageous in ensuring

[0091] Preferably, the thermoplastic resin is a polyester, a polyamide, a polyolefin, or The resin may be one or more resins selected from the group consisting of polyphenylene sulfide and polyphenylene sulfide.

[0092] Specifically, the thermoplastic resin is polyethylene terephthalate, polybutylene terephthalate, Polycyclohexane terephthalate, polyethylene naphthalate, nylon, Consists of polyethylene, polypropylene, polybutylene, and polyphenylene sulfide. The resin may be one or more resins selected from the group consisting of:

[0093] The denier and cross-sectional shape of the thermoplastic resin filaments are not particularly limited. As a non-limiting example, the filaments may have a denier of 1 to 10 and a circular cross section. Or it may have a contoured cross section.

[0094] In order to ensure excellent mechanical properties, the spunbond nonwoven fabric has a density of 20 to 150 g / m 2 , or 50 to 120 g / m 2 The weight per unit area may be 1.0 to 1.0 mm.

[0095] In particular, the spunbond nonwoven fabric is produced according to the above-mentioned "I. Method for producing spunbond nonwoven fabric". This allows the product to be manufactured without any residual harmful substances such as lead (Pb), and has improved It is possible to show the excellent fiber spreading quality.

[0096] According to one embodiment of the invention, the spunbond nonwoven fabric has a content of 0.1 ppmw (ppm by weight). Preferably, the spunbond nonwoven fabric has a residual lead (Pb) content of 0.1% or less. The woven fabric contains no residual lead.

[0097] According to one embodiment of the invention, the spunbond nonwoven fabric is made of bismuth (Bi) or bismuth The filaments are split by impact with a metal member containing a 0.01% alloy. .01ppmw~10.0ppmw, or 0.05ppmw~5.0ppmw, or The residual amount of bismuth (Bi) is preferably 0.1 ppmw to 2.5 ppmw. can.

[0098] In the spunbond nonwoven fabric, the bismuth contained in the bismuth alloy The residual amount of metals other than copper can be expressed as 0.1 ppmw or less. (Cu), zinc (Zn), tin (Sn), aluminum (Al), molybdenum (Mo), and titanium (Ti).

[0099] According to one embodiment of the invention, the spunbond nonwoven fabric has a molecular weight of 350 or more as defined by the following formula 1: It can have the following quality indices (Q):

[0100] [Formula 1] Quality index (Q)=SD / OD

[0101] In the above formula 1, OD is measured using a formation tester. The optical density of the spunbond nonwoven fabric is SD is the standard deviation of the optical density. D).

[0102] The optical density (OD) is the transmittance of a light source per unit area of ​​the spunbond nonwoven fabric; The quality index (Q) is a value obtained by the standard deviation of the optical density. The standard deviation (SD) is normalized by the optical density (OD). The OD and SD are , which can be obtained by using a typical quality evaluation device in the technical field to which the present invention pertains.

[0103] In order to ensure uniform and excellent quality, the spunbond nonwoven fabric has a grade of 350 or less. It is preferable that the spunbond nonwoven fabric has a fiber length of 100 mm or less and a fiber length of 100 mm or less. More preferably, the fiber length of the spunbond nonwoven fabric has a fiber length of 100 mm or less. The rank index (Q) is 250-350, or 270-350, or 275-300. It's fine. Effect of the Invention

[0104] According to the present invention, a new material has the same level of negative charge donating ability as lead (Pb), but is less harmful to the human body. A method for producing a spunbond nonwoven fabric having improved fiber opening quality using a friction material that does not have a friction coefficient of 0.01%. The device is capable of extending the replacement interval of the friction material and improving operability. The spunbond nonwoven fabric produced by the above-mentioned device and method has low residual harmful substances. It does not contain any fluorine and has improved fiber opening quality, making it suitable for industrial materials as well as life science materials. When used in combination with other chemicals, it is possible to eliminate potential risks to human health. [Brief description of the drawings]

[0105] [Figure 1] 1 is a schematic diagram of a spunbond nonwoven fabric manufacturing apparatus according to one embodiment of the present invention; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0106] Preferred examples are presented below for understanding the invention. However, the following examples are not intended to be limiting. These are merely illustrative of the invention and are not intended to limit the invention.

[0107] Example 1 A spunbond nonwoven fabric was produced using the apparatus according to FIG.

[0108] First, it has an intrinsic viscosity (IV) of 0.665 dl / g and a melting point (T m ) The polyethylene terephthalate resin was melted at 284° C. and continuously discharged. The filament bundle obtained by the above is compressed in the cylindrical pipe of the nozzle unit. It is stretched at a speed of 5,000m / min using air and an ejector. At the same time, the EDJ nozzle (electric distribution jet nozzle) The EDJ nozzle was driven by a step motor. r) is connected to the axis, and the rotation angle range of the nozzle is -15±5° to +15±5° and The reciprocating speed of the nozzle was controlled to 10 counters / sec.

[0109] The discharged filament bundle is positioned adjacent to the nozzle unit at a predetermined angle. The collision surface of the collision unit was made of bismuth. A metal member (metal plate with a thickness of 2.0±0.15 mm) made of (Bi) was used. The mass flow rate of the filaments impinging on the metal member is The linear velocity of the filament is 5.0 kg / hr per nozzle. ,000m / min.

[0110] The filament, which has become negatively charged by frictional charging with the collision unit, The filaments are opened by the Coulomb repulsion between them, and the conveyor net is placed The negatively charged filaments are then transported to the grounded continuous conveyor net. On top of that, a fibrous web was formed which was attached by electrostatic forces.

[0111] The fibrous web is passed between calendar rollers that maintain a temperature of 130° C. and a pressure of 35 N / mm. Next, the fiber web is thermally bonded by applying hot air to the fiber web. By this, the spunbond nonwoven fabric (thickness 0.27±0.03mm, weight 60±2.0g) / m 2 ) was obtained.

[0112] Example 2 The collision surface of the collision unit is provided with a bismuth / copper alloy (Bi50 The same as in Example 1 except that a metal member made of 50% by weight and 50% by weight of Cu was used. A spunbond nonwoven fabric was obtained by the above method.

[0113] Comparative Example 1 The collision surface of the collision unit is provided with a metal material made of lead (Pb) instead of a bismuth metal material. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the member was used.

[0114] Comparative Example 2 The collision surface of the collision unit is provided with a metal member made of copper (Cu) instead of a bismuth metal member. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the member was used.

[0115] Comparative Example 3 The collision surface of the collision unit is provided with a metal material made of tin (Sn) instead of a bismuth metal member. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that the member was used.

[0116] Comparative Example 4 The collision surface of the collision unit is made of aluminum (Al) instead of bismuth metal. A spunbond nonwoven fabric was prepared in the same manner as in Example 1, except that a metal member made of obtained.

[0117] Comparative Example 5 The collision surface of the collision unit is provided with a bismuth metal member instead of a zinc (Zn) metal member. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that a metal member was used.

[0118] Comparative Example 6 The collision surface of the collision unit is made of molybdenum (Mo) instead of bismuth metal. The spunbond nonwoven fabric was prepared in the same manner as in Example 1, except that a metal member was used. Got it.

[0119] Comparative Example 7 The collision surface of the collision unit is made of titanium (Ti) instead of bismuth metal. A spunbond nonwoven fabric was obtained in the same manner as in Example 1, except that a metal member was used. .

[0120] Test Example (1) Charge generation amount (nC / sec) Using the Faraday cage method, the opened filament The amount of electrostatic discharge per unit time that a The tic discharge was measured.

[0121] The Faraday cage is divided into an inner cage and an outer cage. The blade collides with the metal member so that the open filaments 22 are trapped. The outer cage is grounded and is installed so as to surround the entire surface of the inner cage. A digital coulomb meter (NK-1002, KASUGA) is placed in the inner cage. The charge amount of the inner cage and the outer cage is adjusted by the following method. The time it takes for the difference to reach -9,000nC is measured using the digital coulomb meter. The amount of electrostatic discharge per unit time of the opened filament is standardized by The average value was obtained.

[0122] (2) Spreading width (mm) The width of the filaments spread by the frictional charging with the collision unit is measured. Here, the spread width is the width of the spread fibers collected on the continuous conveyor net. The spread width means the maximum width based on the lament moving direction. The values ​​of the spread filaments obtained from the impact unit and the corresponding impact unit are The spread width is set as the standard. The rotation angle range of the EDJ nozzle is -15±5° to +15±5°. 10 times under the condition of 10° and the reciprocating speed of the EDJ nozzle of 10 counters / sec. The average value after measurement was shown.

[0123] (3) Quality index (Q) Quality evaluation equipment (Formation tester, FMT-III, Manufac tuered by NOMURA SHOJI CO.) to create spunbond nonwoven fabric The transmittance of the light source per unit area and the distribution of the transmittance give the optical density (OD) and The standard deviation (SD) of the optical density was measured, and the quality index was calculated according to the above formula 1.

[0124] The quality evaluation device (FMT-III) is an image analysis type quality evaluation device using a 2D CCD camera. The nonwoven sample is placed on a stage illuminated from below. The CD camera captures an image of 320x230 pixels, with each pixel representing The light intensity is measured. A PC linked to a CCD camera converts the light intensity into transmittance (%) and and convert to optical density (OD).

[0125] (4) Use period of metal parts (days) During the manufacturing process of spunbond nonwoven fabric, the metal parts (thickness 2. The point at which holes appear in the thickness direction of a metal plate with a thickness of 0±0.15 mm, or when unevenness occurs due to wear. The time when the operability decreased due to the occurrence of the filament colliding with the metal member was measured. The mass flow rate of the grease is 1 / 10 ... The linear speed of the filament is limited to 5,000 m / min. Controlled.

[0126] (5) Inorganic residue amount (ppmw) Inductively Coupled Plasma (ICP) was used to measure inorganic residues in spunbond nonwoven fabrics. The spunbond nonwoven test pieces were pretreated with an aqueous solution from which particles and organic matter had been removed by acid digestion. The amount of inorganic matter remaining in the specimens was primarily determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES). When residual inorganic matter was not detected, the measurement was performed using inductively coupled The measurements were repeated with increased resolution using inductively coupled plasma-mass spectrometry (ICP-MS).

[0127] [Table 1]

[0128] Referring to Table 1, Comparative Example 1 was excellent in quality index and spread width, but the nonwoven fabric Residual lead was detected, making it unsuitable for use in life science materials.

[0129] In the examples, the nonwoven fabric had the same quality index and spread width as those in Comparative Example 1, but No residual harmful substances were detected from the metal members used in the examples. It has been confirmed that the operating efficiency has been significantly improved since the operating cycle is approximately twice as long as that of the conventional type. It was.

[0130] In Comparative Examples 2 and 3, the amount of inorganic matter remaining in the nonwoven fabric was low, but the quality index and spread width were poor. In Comparative Examples 4 to 7, no residual inorganic matter was detected in the nonwoven fabric, but the filaments It was confirmed that the fiber opening was poor. [Explanation of symbols]

[0131] 10: Nozzle unit 11: Filament bundle 20: Collision unit 22: Open filament 30: Conveyor net 33: Fiber web

Claims

1. melt spinning a thermoplastic resin to obtain a continuous filament bundle; The continuous filament bundle is then coated with a gold containing bismuth (Bi) or a bismuth alloy. a step of causing the filaments to collide with a metal member to obtain filaments opened by frictional charging; The opened filaments are collected on a continuous conveyor net to form a fibrous web. Stages and A method for producing a spunbond nonwoven fabric comprising the steps of:

2. The bismuth alloy contains 10% by weight or more of bismuth based on the weight of the bismuth alloy. The method of claim 1 , comprising:

3. The bismuth alloy is made of copper (Cu), zinc (Zn), tin (Sn), aluminum (Al ), molybdenum (Mo), and titanium (Ti). The method of claim 1 , further comprising the step of:

4. The continuous filament bundle has a speed of 4,000 m / min to 6,000 m / min. and a linear velocity of 2 per nozzle for ejecting the continuous filament bundle. .0 kg / hr to 8.0 kg / hr of mass flow rate to impinge on said metal member. A method for producing a spunbonded nonwoven fabric according to claim 1.

5. The opened filaments are charged at −3500 nC / sec to −50 1. The present invention relates to a charge generating device having a charge generation rate of 0 nC / sec (measured by a Faraday cage method). A method for producing a spunbonded nonwoven fabric according to claim 1.

6. The opened filaments are formed by changing the rotation angle of the nozzle for spraying the filament bundle. The angle range is -15±5° to +15±5° and the reciprocating speed of the nozzle is 3 counters / sec. c to 12 counter / sec, with a spread width of 500 mm or more, The fibers are collected on a continuous conveyor net (wherein the spread width is collected on the continuous conveyor net). (meaning the maximum width of the opened filaments relative to the moving direction of the opened filaments) A method for producing a spunbonded nonwoven fabric according to claim 1.

7. The thermoplastic resin has a melting point of 200° C. or higher, The thermoplastic resin may be a polyester, a polyamide, a polyolefin, or a polyphenylene. One or more resins selected from the group consisting of toluene sulfide, A method for producing the spunbond nonwoven fabric according to claim 1.

8. The thermoplastic resin is polyethylene terephthalate, polybutylene terephthalate, Cyclohexane terephthalate, polyethylene naphthalate, nylon, polyethylene , polypropylene, polybutylene, and polyphenylene sulfide. The method for producing a spunbond nonwoven fabric according to claim 1, wherein the one or more resins are selected from the group consisting of tungsten, tungsten, tungsten-based ...

9. A plurality of nozzle units arranged and configured to eject a continuous filament bundle. Knit and Collision with the continuous filament bundle discharged by the nozzle unit an impingement unit adjacent each of the nozzle units at a position for impinging the nozzles; The filaments that are opened by frictional charging with the collision unit are collected and transported. a continuous conveyor net; The collision unit is a metal member containing bismuth (Bi) or a bismuth alloy. Including faces, Spunbond nonwoven fabric manufacturing equipment.

10. The bismuth alloy contains 10% by weight or more of bismuth based on the weight of the bismuth alloy. The spunbond nonwoven fabric manufacturing apparatus according to claim 9 .

11. The bismuth alloy is made of copper (Cu), zinc (Zn), tin (Sn), aluminum (Al ), molybdenum (Mo), and titanium (Ti). The apparatus for producing a spunbond nonwoven fabric according to claim 9, further comprising:

12. The nozzle unit includes a jet nozzle for discharging the continuous filament bundle. (jet nozzle), The jet nozzle is connected to a step motor shaft; Nozzle rotation angle range of 15±5° to +15±5° and 3 counter / sec to 1 Controlled by the nozzle reciprocation speed of 2 counters / sec. The apparatus for producing a spunbond nonwoven fabric according to claim 9.

13. Obtained by the method according to claim 1, A fibrous web including thermoplastic filaments, having a residual amount of bismuth (Bi) of 0.01 ppmw to 10.0 ppmw; Spunbond nonwoven fabric.

14. The spunbond nonwoven fabric has a residual amount of lead (Pb) of 0.1 ppmw or less. The spunbond nonwoven fabric of claim 13.

15. The spunbond nonwoven fabric has a quality index (Q) of 350 or less, as defined by the following formula 1: The spunbond nonwoven fabric of claim 13, [Formula 1] Quality index (Q) = SD / OD In the above formula 1, OD is measured using a formation tester. The optical density of the spunbond nonwoven fabric is determined as , SD is the standard deviation of the optical density D).

16. The thermoplastic resin has a melting point of 200° C. or higher, The thermoplastic resin may be a polyester, a polyamide, a polyolefin, or a polyphenylene. One or more resins selected from the group consisting of toluene sulfide, The spunbond nonwoven fabric of claim 13.

17. The thermoplastic resin is polyethylene terephthalate, polybutylene terephthalate, Cyclohexane terephthalate, polyethylene naphthalate, nylon, polyethylene , polypropylene, polybutylene, and polyphenylene sulfide.

14. The spunbond nonwoven fabric of claim 13, wherein the one or more resins are selected from the group consisting of tungsten, ...-based and tungsten-based.

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