The present disclosure relates to a melt spinning apparatus and a method for manufacturing a nonwoven fabric.
Background technology
[0002]
As a method for manufacturing a spunbonded non-woven fabric, there is a method in which a spun filament is cooled by a cooling air introduced into a cooling chamber, and then the cooling air is drawn out as a stretched air as it is through a nozzle and sprayed on a mesh belt.
[0003]
In the manufacturing process of spunbonded non-woven fabric, the filament is cooled by blowing cooling air on a large number of continuous filaments melt-spun from the spinning nozzle. At this time, if the discharge amount of the filament is increased in order to increase the productivity, a sufficient amount of cooling air is required accordingly. If the amount of cooling air is small, the filament will not be cooled sufficiently, and resin lumps (shots) will easily occur on the web. On the other hand, if there is a lot of cooling air, thread breakage is likely to occur due to supercooling.
[0004]
Therefore, there has been proposed a method and apparatus for producing a non-woven fabric, which can reduce the fiber diameter without causing yarn breakage even if the amount of cooling air is increased and without reducing the productivity, and can stably produce the non-woven fabric. (See, for example, Patent Document 1). Specifically, in Patent Document 1, a non-woven fabric in which the cooling air introduced into the cooling chamber is divided into at least two stages in the vertical direction, and the wind speed of the cooling air at the bottom stage is higher than the wind speed of the cooling air at the top stage. The manufacturing method of is proposed.
Prior art literature
Patent documents
[0005]
Patent Document 1: Japanese Patent Application Laid-Open No. 2002-317372
Outline of the invention
Problems to be solved by the invention
[0006]
However, the method and apparatus for manufacturing a nonwoven fabric proposed in Patent Document 1 have a problem that the uniformity (texture) of the mass distribution of the entire nonwoven fabric tends to be poor and so-called yarn sway is likely to occur.
[0007]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a melt spinning apparatus capable of suppressing yarn breakage and yarn sway, and a method for producing a nonwoven fabric using this apparatus.
Means to solve problems
[0008]
The means for solving the above-mentioned problems include the following aspects.
<1> A spinning section equipped with a plurality of spinning nozzles for spinning filaments,
A cooling unit that cools the filament spun from the spinning nozzle,
A cooling air supply unit that faces the cooling unit and supplies cooling air to the cooling unit via a breathable partition wall is provided.
The cooling air supply unit includes a first cooling air supply unit on the vertically upper side and a second cooling air supply unit on the vertically lower side divided into two stages in the vertical direction via a partition wall, and the air-permeable partition wall of the partition wall is provided. A melt spinning device in which there is a gap between the end facing the partition wall and the surface of the breathable partition wall on the side facing the partition wall, and the distance (distance A) of the gap is 55 mm or less.
<2> The melt spinning apparatus according to <1>, wherein the distance A is 5 mm or more.
<3> The ratio (distance B / distance A) of the distance (distance B) from the nozzle surface provided with the spinning nozzle of the spinning portion to the partition wall with respect to the distance A is 5 to 50 <1> or. The melt spinning apparatus according to <2>.
<4> The ratio of the height (h 2) of the second cooling air supply unit to the height (h 1) of the first cooling air supply unit is 0.5 to 1.5 <1> to <. The melt spinning apparatus according to any one of 3>.
<5> The melt spinning apparatus according to any one of <1> to <4>, wherein the thickness of the breathable partition wall is 10 mm to 50 mm.
<6> The ratio of the thickness of the breathable partition wall to the distance A (thickness of the breathable partition wall / distance A) is 0.5 to 5.0, whichever is one of <1> to <5>. The melt spinning apparatus according to.
<7> The melt spinning apparatus according to any one of <1> to <6>, wherein the breathable partition wall has a honeycomb shape.
<8> Any of <1> to <7>, the cooling air supply unit includes a rectifying plate for rectifying the cooling air supplied to the cooling unit on the upstream side of the air-permeable partition wall in the cooling air supply direction. The melt spinning apparatus according to one.
<9> The temperature of the cooling air supplied to the first cooling air supply unit is 10 ° C to 40 ° C, and the temperature of the cooling air supplied to the second cooling air supply unit is the temperature of the first cooling air supply. The melt spinning apparatus according to any one of <1> to <8>, comprising a first control unit that is 10 ° C. or more higher than the temperature of the cooling air supplied to the unit and controls the temperature to 30 ° C. to 70 ° C.
<10> The ratio (V 1 /) of the average wind speed (V 1) of the cooling air supplied to the first cooling air supply unit to the average wind speed (V 2) of the cooling air supplied to the second cooling air supply unit. The melt spinning apparatus according to any one of <1> to <9>, comprising a second control unit for controlling V 2) to more than 0 and 0.7 or less.
<11> Further provided with a stretched portion for stretching the filament cooled by the cooling portion.
The distance (distance B) from the nozzle surface provided with the spinning nozzle of the spinning portion to the partition wall with respect to the distance (distance C) from the nozzle surface provided with the spinning nozzle of the spinning portion to the entrance of the stretching portion. The melt spinning apparatus according to any one of <1> to <10>, wherein the ratio (distance B / distance C) is 0.2 to 0.8.
<12> The invention according to any one of <1> to <11>, further comprising a collecting portion for collecting cooled and stretched filaments to form a non-woven web, and used for producing a spunbonded nonwoven fabric. Melt spinning equipment.
[0009]
<13> A method for producing a nonwoven fabric from filaments spun from the plurality of spinning nozzles using the melt spinning apparatus according to any one of <1> to <12>.
<14> The temperature of the cooling air supplied to the first cooling air supply unit is 10 ° C to 40 ° C, and the temperature of the cooling air supplied to the second cooling air supply unit is the temperature of the first cooling air supply. The method for producing a non-woven fabric according to <13>, wherein the temperature is 10 ° C. or higher and 30 ° C. to 70 ° C. higher than the temperature of the cooling air supplied to the unit.
<15> The ratio (V 1 /) of the average wind speed (V 1) of the cooling air supplied to the first cooling air supply unit to the average wind speed (V 2) of the cooling air supplied to the second cooling air supply unit. V 2) is the method for producing a non-woven fabric according to <13> or <14>, which is more than 0 and 0.7 or less.
<16> The method for producing a nonwoven fabric according to any one of <13> to <15>, wherein the filament contains a propylene-based polymer.
The invention's effect
[0010]
The present disclosure can provide a melt spinning apparatus capable of suppressing yarn breakage and yarn sway, and a method for producing a nonwoven fabric using this apparatus.
A brief description of the drawing
[0011]
FIG. 1 is a schematic configuration diagram showing a partial cross section of the melt spinning apparatus of the present disclosure.
FIG. 2 is a graph showing the relationship between the height of the cooling air supply unit of Examples 1 to 3 and the wind speed (outlet value) of the cooling air.
FIG. 3 is a graph showing the relationship between the height of the cooling air supply unit of Examples 1 to 3 and Comparative Examples 1 to 6 and the wind speed (outlet value) of the cooling air.
Embodiment for carrying out the invention
[0012]
Hereinafter, specific embodiments of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and the present invention is carried out with appropriate modifications within the scope of the object of the present invention. be able to.
In the present disclosure, the numerical range represented by using "-" means a range including the numerical values ​​before and after "-" as the lower limit value and the upper limit value.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in another stepwise description. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
When the embodiment is described in the present disclosure with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. Further, the size of the members in each figure is conceptual, and the relative relationship between the sizes of the members is not limited to this.
[0013]
[Melting spinning equipment]
The melt spinning apparatus of the present disclosure has a spinning section including a plurality of spinning nozzles for spinning filaments, a cooling section for cooling the filaments spun from the spinning nozzles, and a breathable partition wall facing the cooling section. The cooling air supply unit is provided with a cooling air supply unit that supplies cooling air to the cooling unit via a partition wall, and the cooling air supply unit is a vertically upper first cooling air supply unit divided into two stages in the vertical direction via a partition wall. A second cooling air supply unit on the vertically lower side is provided, and there is a gap between the end of the partition facing the air-permeable partition and the surface of the air-permeable partition facing the partition. The distance (distance A) is 55 mm or less.
[0014]
The melt spinning apparatus of the present disclosure includes a cooling air supply unit including a first cooling air supply unit on the vertically upper side and a second cooling air supply unit on the vertically lower side, which are divided into two stages in the vertical direction via a partition wall. There is a gap between the end of the partition wall facing the breathable partition wall and the surface of the breathable partition wall facing the partition wall, and the gap distance (distance A) is 55 mm or less. As a result, the difference in wind speed at the boundary between the first cooling air supply section on the vertically upper side and the second cooling air supply section on the vertically lower side can be reduced, and the difference in wind speed is small near this boundary. Since the cooling air is supplied to the filament, it is presumed that the turbulence caused by mixing the cooling air having different wind speeds can be suppressed and the thread breakage and the thread sway can be suppressed.
[0015]
Hereinafter, the configuration of the melt spinning apparatus of the present disclosure will be described with reference to FIG. 1. As shown in FIG. 1, the melt spinning device 100 includes a spinning section 1, a cooling chamber (cooling section) 3, a cooling air supply section 4, a breathable partition wall 8, and a drawing section 9. Further, the cooling air supply unit 4 is divided into two stages via a partition wall 7, and includes a first cooling air supply unit 5 on the vertically upper side and a second cooling air supply unit 6 on the vertically lower side. .. Further, there is a gap between the end of the partition wall 7 facing the breathable partition wall 6 and the surface of the breathable partition wall 6 facing the partition wall 7.
[0016]
The melt spinning device 100 is a device that discharges the resin composition supplied to the spinning unit 1 from a plurality of spinning nozzles into the cooling chamber 3 to cool and stretch the discharged filaments. Further, the melt spinning apparatus 100 may be an apparatus used for producing a spunbonded nonwoven fabric, and may include, for example, a collecting portion for forming a non-woven web for depositing cooled and stretched filaments. It may be provided with an entanglement portion for heat-pressurizing the woven web.
[0017]
The melt spinning device 100 includes a spinning unit 1 including a plurality of spinning nozzles for spinning filaments. For example, a resin composition melt-kneaded by an extruder is supplied to the spinning section 1, and the resin composition supplied to the spinning section 1 is cooled from a plurality of spinning nozzles provided on the nozzle surface 2. It is discharged as a filament into the chamber 3.
[0018]
The resin composition may contain a resin used for producing a non-woven fabric. Examples of the resin used for producing the non-woven fabric include polyester resin, polyurethane resin, polyamide resin, polyolefin resin and the like. Among them, polyolefin resins are preferable, and propylene-based polymers are more preferable, because they are excellent in productivity.
[0019]
The propylene-based polymer may be a polymer containing propylene as a constituent unit, a propylene homopolymer, a propylene random copolymer, or a mixture thereof.
[0020]
The propylene random copolymer is preferably a random copolymer having a propylene content of 50 mol% or more with respect to all the constituent units. The propylene random copolymer is preferably a propylene / α-olefin random copolymer.
[0021]
As the propylene random copolymer, the content of propylene with respect to all the constituent units is preferably 70 mol% to 99.5 mol%, more preferably 80 mol% to 98 mol%, still more preferably 90 mol% to 96 mol%. ..
[0022]
As the α-olefin, α-olefins having 2 or more carbon atoms excluding propylene are preferable, α-olefins having 2 or 4 to 8 carbon atoms are more preferable, and ethylene, which is an α-olefin having 2 carbon atoms, is further preferable. ..
[0023]
Specific examples of the α-olefin include ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 4-methyl-1-pentene and the like.
The α-olefin may be used alone or in combination of two or more.
[0024]
Resin composition May contain other components together with the resin used for producing the nonwoven fabric. Other components include, for example, other polymers, organic peroxides, surfactants, colorants, phosphorus-based, phenol-based and other antioxidants, benzotriazole-based and other weather-resistant stabilizers, and hindered amine-based light-resistant agents. Stabilizers, blocking inhibitors, dispersants such as calcium stearate, lubricants, nucleating agents, pigments, softeners, hydrophilic agents, water repellents, auxiliaries, water repellents, fillers, antibacterial agents, pesticides, insect repellents, chemicals , Natural oil, synthetic oil and the like.
[0025]
The melt spinning device 100 includes a cooling chamber 3 for cooling the filament spun from the spinning nozzle. Cooling air is supplied from the cooling air supply unit 4 into the cooling chamber 3 via the air-permeable partition wall 8, and the filament is cooled by the supplied cooling air. Further, an exhaust nozzle for exhausting the vapor of the low molecular weight polymer may be mounted between the nozzle surface 2 which is the upper part of the cooling chamber 3 and the cooling air supply unit 4.
[0026]
The melt spinning device 100 faces the cooling chamber 3 and includes a cooling air supply unit 4 that supplies cooling air to the cooling chamber 3 via the breathable partition wall 8. The cooling air supply unit 4 includes a first cooling air supply unit 5 on the vertically upper side and a second cooling air supply unit 6 on the vertically lower side, which are divided into two stages in the vertical direction. As shown in FIG. 1, the first cooling air supply unit 5 and the second cooling air supply unit 6 supply cooling air in the direction of the arrow in FIG.
[0027]
As shown in FIG. 1, the cooling air supply unit 4 supplies cooling air to the cooling chamber 3 from two facing directions via the air-permeable partition wall 8.
[0028]
The cooling air supply unit 4 may be provided with a rectifying plate that rectifies the cooling air supplied to the cooling chamber 3 on the upstream side of the air-permeable partition wall 8 in the cooling air supply direction. As a result, the direction of the cooling air supplied to the cooling chamber 3 is adjusted, and yarn breakage and yarn sway can be suppressed more preferably.
[0029]
Assuming that the width of the cooling air supply unit 4 is L (m), the height of the cooling air supply unit 4 is h (m), and the gap distance is d (mm), (L × h) / d is 0. It is preferable to satisfy 056 or more. Here, the height h of the cooling air supply unit 4 corresponds to the thickness of h 1 + h 2 + partition wall 7 in FIG. 1, and the width of the cooling air supply unit 4 corresponds to the supply direction of the cooling air and cooling in FIG. It is the inner length excluding the outer wall of the cooling air supply unit 4 in the direction orthogonal to the height of the air supply unit 4.
Further, the width L of the cooling air supply unit 4 and the height h of the cooling air supply unit 4 mean the width and height at the cooling air outlet of the cooling air supply unit 4. Therefore, (L × h) means the area of ​​the surface through which the cooling air passes at the cooling air outlet of the cooling air supply unit 4, and (L × h) / d means the ratio of this area to the gap distance d. ..
[0030]
(L × h) / d may be 0.056 to 0.614 or 0.112 to 0.448. When (L × h) / d is 0.056 or more, yarn breakage can be suppressed more preferably, and when (L × h) / d is 0.614 or less, yarn wobbling is further suppressed. It can be suitably suppressed.
[0031]
The gap distance d may be 50 mm or less, 45 mm or less, or 40 mm or less from the viewpoint of more preferably suppressing thread breakage.
[0032]
Further, the gap distance d is not particularly limited as long as the gap exists, and may be 5 mm or more or 10 mm or more from the viewpoint of more preferably suppressing the yarn sway.
[0033]
The width L of the cooling air supply unit 4 is not particularly limited, and may be 3 m to 7 m or 4 m to 6 m. Further, the height of the cooling air supply unit 4 is not particularly limited, and may be 0.4 m to 1.0 m or 0.6 m to 0.8 m.
[0034]
The ratio (distance B / distance A) of the distance (distance B) from the nozzle surface 2 to the partition wall 7 to the distance A, which is the distance d of the gap, may be 5 to 50.
[0035]
The ratio of the height (h 2) of the second cooling air supply unit 6 to the height (h 1) of the first cooling air supply unit 5 may be 0.5 to 1.5, and may be 0.8 to 0.5. It may be 1.2.
[0036]
The melt spinning apparatus 100 controls the temperature of the cooling air supplied to the first cooling air supply unit 5 (first temperature) and the temperature of the cooling air supplied to the second cooling air supply unit 6 (second temperature). A first control unit may be further provided.
The above-mentioned first temperature refers to the temperature of the cooling air at the inlet of the first cooling air supply unit 5, and the above-mentioned second temperature refers to the temperature of the cooling air at the inlet of the second cooling air supply unit 6.
[0037]
The first control unit preferably controls the second temperature to be higher than the first temperature from the viewpoint of more preferably suppressing yarn breakage, and sets the first temperature to 10 ° C to 40 ° C and the second. It is more preferable to control the temperature to be 10 ° C. or higher higher than the first temperature and 30 ° C. to 70 ° C.
[0038]
The melt spinning apparatus 100 controls the average wind speed (V 1) of the cooling air supplied to the first cooling air supply unit 5 and the average wind speed (V 2) of the cooling air supplied to the second cooling air supply unit 6. A second control unit may be further provided. The second control unit may be the same as or different from the first control unit.
Note that V 1 refers to the average wind speed of the cooling air at the inlet of the first cooling air supply unit 5, and V 2 refers to the average wind speed of the cooling air at the inlet of the second cooling air supply unit 6.
[0039]
The second control unit preferably controls the average wind speed of the cooling air so that V 2 is larger than V 1 from the viewpoint of preferably suppressing yarn breakage.
[0040]
The second control unit preferably controls the ratio of V 1 to V 2 (V 1 / V 2) to be more than 0 and 0.7 or less from the viewpoint of more preferably suppressing yarn breakage, 0.01. It is more preferable to control to ≦ V 1 / V 2 ≦ 0.5, and further preferably to control to 0.05 ≦ V 1 / V 2 ≦ 0.4.
[0041]
The melt spinning device 100 includes a breathable partition wall 8 that separates the cooling air supply unit 4 and the cooling chamber 3. Since the breathable partition wall 8 has air permeability, the cooling air supplied from the cooling air supply unit 4 is introduced into the cooling chamber 3 via the breathable partition wall 8.
[0042]
The breathable partition wall 8 is not particularly limited as long as it is a breathable partition wall, and preferably has a lattice shape such as a square shape, a honeycomb shape such as a hexagonal shape, or an octagonal shape from the viewpoint of rectification of cooling air. It is more preferable to have a shape.
[0043]
The thickness of the breathable partition wall 8 is preferably 10 mm to 50 mm, more preferably 20 mm to 40 mm from the viewpoint of strength and rectification of cooling air.
[0044]
The ratio of the thickness of the breathable partition wall to the distance A (thickness of the breathable partition wall / distance A) is preferably 0.5 to 5.0, and more preferably 0.5 to 1.5. , 0.8 to 1.2 is more preferable.
[0045]
The melt spinning device 100 further includes a drawing portion 9 for stretching the filament cooled in the cooling chamber 3. The extension portion 9 is a narrow bottleneck arranged vertically below the cooling chamber 3 and narrowed from both the left and right sides. The cooling air increases the wind speed at the stretching portion 9 to become stretching air, and stretches the cooled filament.
[0046]
The ratio (distance B / distance C) of the distance (distance B) from the nozzle surface 2 to the partition wall 7 with respect to the distance (distance C) from the nozzle surface 2 to the entrance of the extending portion 9 is 0.2 to 0.8. It is preferably 0.2 to 0.6, and more preferably 0.2 to 0.6.
[0047]
[Manufacturing method of non-woven fabric]
The method for producing a nonwoven fabric of the present disclosure is a method of producing a nonwoven fabric from filaments spun from a plurality of spinning nozzles using the above-mentioned melt spinning apparatus of the present disclosure. By this method, a non-woven fabric in which yarn breakage and yarn sway are suppressed can be obtained.
[0048]
The method for producing a nonwoven fabric of the present disclosure includes, for example, a step of discharging a resin composition supplied to a spinning section from a plurality of spinning nozzles into a cooling section, a step of cooling the discharged filament, and a step of cooling the cooled filament. It may include a step of stretching and a step of collecting the stretched filaments to form a non-woven web. Further, the method for producing a nonwoven fabric of the present disclosure may include a step of heat-pressurizing a non-woven web.
[0049]
The temperature of the cooling air supplied to the first cooling air supply unit is 10 ° C. to 40 ° C., and the temperature of the cooling air supplied to the second cooling air supply unit is 10 ° C. to 40 ° C. from the viewpoint of more preferably suppressing thread breakage. It is preferably 10 ° C. or higher and 30 ° C. to 70 ° C. higher than the temperature of the cooling air supplied to the first cooling air supply unit.
[0050]
The average wind speed (V 2) of the cooling air supplied to the second cooling air supply unit is higher than the average wind speed (V 1) of the cooling air supplied to the first cooling air supply unit from the viewpoint of appropriately suppressing thread breakage. Is preferably large. Further, from the viewpoint of more preferably suppressing yarn breakage, the ratio of V 1 to V 2 (V 1 / V 2) is preferably more than 0 and 0.7 or less, and 0.01 ≦ V 1 / V 2. It is more preferably ≦ 0.5, and even more preferably 0.05 ≦ V 1 / V 2 ≦ 0.4.
[0051]
Further, by controlling V 1 and V 2, the average wind speed (V 1') of the cooling air supplied from the first cooling air supply unit to the cooling unit and the supply from the second cooling air supply unit to the cooling unit. The average wind speed (V 2') of the cooling air may be adjusted. For example, by controlling V 1 and V 2, the ratio of V 1'to V 2'(V 1'/ V 2') may be adjusted to be more than 0 and 0.7 or less. It may be adjusted so that 1.01 ≦ V 1 ′ / V 2 ′ ≦ 0.5, or 0.1 ≦ V 1 ′ / V 2 ′ ≦ 0.5.
Example
[0052]
Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.
[0053]
[Examples 1 to 3 and Comparative Examples 1 to 6]
A non-woven fabric was manufactured using the melt spinning apparatus shown in FIG. As the resin used for producing the non-woven fabric, a propylene homopolymer having a melt flow rate of 60 g / 10 min measured at a load of 2.16 kg and a temperature of 230 ° C. according to ASTM D1238 was used. The melting temperature of the resin was 200 ° C., the single-hole discharge amount from the spinning nozzle was 0.57 g / min, and the wind speed of the cooling air was as shown in Table 1. The temperature of the upper cooling air and the temperature of the lower cooling air are 23 ° C., and the lower cooling air supply unit (second cooling air supply unit) with respect to the height (h1) of the upper cooling air supply unit (first cooling air supply unit). ) Was 1 in height (h 2), and distance B / distance C was 0.47. The thickness of the partition wall was 1/16 of the height of the upper cooling air supply section.
[0054]
The supply unit inlet value shown in Table 1 refers to the average wind speed value of the cooling air supplied to the inlet of the upper cooling air supply unit or the lower cooling air supply unit.
The supply unit outlet value shown in Table 1 refers to the average wind speed value of the cooling air discharged from the outlet (breathable partition wall) of the upper cooling air supply unit or the lower cooling air supply unit.
An anemomaster anemometer (Model 6114) manufactured by KANOMAX was used for wind speed measurement.
[0055]
2 and 3 show graphs showing the relationship between the height of the cooling air supply unit and the wind speed (outlet value) of the cooling air in Examples 1 to 3 and Comparative Examples 1 to 6. Regarding the height position of the cooling air supply unit in FIGS. 2 and 3, the upper end height position of the upper cooling air supply unit is the upper end of the vertical axis of the graph, and the lower end height position of the lower cooling air supply unit is the vertical position of the graph. The lower end of the axis and the height position of the diaphragm correspond to the center of the vertical axis of the graph.
[0056]
The nonwoven fabrics obtained in Examples 1 to 3 and Comparative Examples 1 to 6 were evaluated for yarn breakage and yarn sway in order to evaluate spinnability.
[0057]

Thread breakage was evaluated by the observation results when the melt-kneaded propylene homopolymer was continuously spun and molded for 10 minutes. The results are shown in Table 1.
-Evaluation criteria-
A: No thread breakage
B: There is a thread break
[0058]

The yarn sway was evaluated by spinning and molding a melt-kneaded propylene homopolymer and observing the yarn sway state at a position B from the nozzle surface in the cooling section (a height position where a partition wall was provided). The results are shown in Table 1.
-Evaluation criteria-
A: No thread sway (the amplitude of filament sway does not come into contact with adjacent filaments)
B: There is thread sway (the amplitude of the sway of the filament is the adjacent filler.May come into contact with mento
[0059]
[table 1]

[0060]
As shown in Table 1 and FIGS. 2 and 3, in Examples 1 to 3, the upper limit wind speed difference (value obtained by subtracting the maximum wind speed in the lower stage from the maximum wind speed in the upper stage) is smaller than that in Comparative Examples 1 to 6, and the yarn breaks. And thread sway was suppressed.
Code description
[0061]
1 Spinning department
2 Nozzle surface
3 Cooling room (cooling part)
4 Cooling air supply unit
5 First cooling air supply unit
6 Second cooling air supply unit
7 partition wall
8 Breathable bulkhead
9 Extension part
10 filament
100 melt spinning equipment
The scope of the claims
[Claim 1]
A spinning section equipped with multiple spinning nozzles for spinning filaments,
A cooling unit that cools the filament spun from the spinning nozzle,
A cooling air supply unit that faces the cooling unit and supplies cooling air to the cooling unit via a breathable partition wall is provided.
The cooling air supply unit includes a first cooling air supply unit on the vertically upper side and a second cooling air supply unit on the vertically lower side divided into two stages in the vertical direction via a partition wall, and the air-permeable partition wall of the partition wall is provided. A melt spinning device in which there is a gap between the end facing the partition wall and the surface of the breathable partition wall on the side facing the partition wall, and the distance (distance A) of the gap is 55 mm or less.
[Claim 2]
The melt spinning apparatus according to claim 1, wherein the distance A is 5 mm or more.
[Claim 3]
Claim 1 or claim 2 in which the ratio (distance B / distance A) of the distance (distance B) from the nozzle surface provided with the spinning nozzle of the spinning portion to the partition wall with respect to the distance A is 5 to 50. The melt spinning apparatus according to the above.
[Claim 4]
The ratio of the height (h 2) of the second cooling air supply unit to the height (h 1) of the first cooling air supply unit is 0.5 to 1.5. The melt spinning apparatus according to any one of the following items.
[Claim 5]
The melt spinning apparatus according to any one of claims 1 to 4, wherein the thickness of the breathable partition wall is 10 mm to 50 mm.
[Claim 6]
The one according to any one of claims 1 to 5, wherein the ratio of the thickness of the breathable partition wall to the distance A (thickness of the breathable partition wall / distance A) is 0.5 to 5.0. Melt spinning equipment.
[Claim 7]
The melt spinning apparatus according to any one of claims 1 to 6, wherein the breathable partition wall has a honeycomb shape.
[Claim 8]
The invention according to any one of claims 1 to 7, wherein the cooling air supply unit includes a rectifying plate for rectifying the cooling air supplied to the cooling unit on the upstream side of the air-permeable partition wall in the cooling air supply direction. The melt spinning apparatus according to the description.
[Claim 9]
The temperature of the cooling air supplied to the first cooling air supply unit is 10 ° C to 40 ° C, and the temperature of the cooling air supplied to the second cooling air supply unit is supplied to the first cooling air supply unit. The melt spinning apparatus according to any one of claims 1 to 8, further comprising a first control unit that is 10 ° C. or more higher than the temperature of the cooling air and controls the temperature to 30 ° C. to 70 ° C.
[Claim 10]
The ratio (V 1 / V 2) of the average wind speed (V 1) of the cooling air supplied to the first cooling air supply unit to the average wind speed (V 2) of the cooling air supplied to the second cooling air supply unit. The melt-spinning apparatus according to any one of claims 1 to 9, further comprising a second control unit for controlling 0 to 0.7 or less.
[Claim 11]
Further provided with a stretched portion for stretching the filament cooled by the cooling portion.
The distance (distance B) from the nozzle surface provided with the spinning nozzle of the spinning portion to the partition wall with respect to the distance (distance C) from the nozzle surface provided with the spinning nozzle of the spinning portion to the entrance of the stretching portion. The melt spinning apparatus according to any one of claims 1 to 10, wherein the ratio (distance B / distance C) is 0.2 to 0.8.
[Claim 12]
The melt spinning apparatus according to any one of claims 1 to 11, further comprising a collecting portion for collecting cooled and stretched filaments to form a non-woven web, and used for producing a spunbonded nonwoven fabric. ..
[Claim 13]
A method for producing a nonwoven fabric from filaments spun from the plurality of spinning nozzles using the melt spinning apparatus according to any one of claims 1 to 12.
[Claim 14]
The temperature of the cooling air supplied to the first cooling air supply unit is 10 ° C. to 40 ° C., and the temperature of the cooling air supplied to the second cooling air supply unit is supplied to the first cooling air supply unit. The method for producing a non-woven fabric according to claim 13, wherein the temperature is 10 ° C. or higher and 30 ° C. to 70 ° C. higher than the temperature of the cooling air.
[Claim 15]
The ratio (V 1 / V 2) of the average wind speed (V 1) of the cooling air supplied to the first cooling air supply unit to the average wind speed (V 2) of the cooling air supplied to the second cooling air supply unit. Is the method for producing a non-woven fabric according to claim 13 or 14, wherein is more than 0 and 0.7 or less.
[Claim 16]
The method for producing a nonwoven fabric according to any one of claims 13 to 15, wherein the filament contains a propylene-based polymer.