Meltblown device

Abstract

The present invention provides a melt-blowing device. The amount of resin discharged from a nozzle can be increased. The device is provided with: a plurality of resin nozzles for discharging molten polymer; an air flow generating section having: a high-temperature air generating section for generating high-temperature air; and an air nozzle disposed adjacent to the resin nozzle and discharging the high-temperature air generated by the high-temperature air generating section; and a collecting section for collecting fibrous resin generated by extending the air discharged from the air nozzle by the molten polymer. The plurality of resin nozzles are arranged in a row and have a plurality of nozzle holes disposed adjacent to each other.

Description

Technical Field

[0001] The invention relates to a melt-blowing device. Background Art

[0002] Patent Document 1 discloses an ultrafine fiber generating device in which a plurality of nozzles are arranged in a row.

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent No. 6187925 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the invention described in Patent Document 1, only one nozzle hole is formed in one nozzle, and Patent Document 1 does not disclose a subject of increasing the amount of resin discharged from one nozzle.

[0008] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a melt-blowing device capable of increasing the amount of resin discharged from one nozzle.

[0009] Means for solving problems

[0010] In order to solve the above-mentioned problems, the meltblowing device involved in the present invention is characterized in that, for example, it is provided with: a plurality of resin nozzles for discharging molten polymer; an air flow generating section, comprising: a high-temperature air generating section for generating high-temperature air and an air nozzle arranged adjacent to the resin nozzle for discharging the high-temperature air generated by the high-temperature air generating section; a capturing section for capturing fibrous resin generated by the molten polymer extending through the air discharged from the air nozzle, wherein the plurality of resin nozzles are arranged in a row, and the resin nozzle has a plurality of nozzle holes arranged adjacent to each other.

[0011] According to the melt-blowing device of the present invention, each of the plurality of resin nozzles arranged in a row has a plurality of nozzle holes arranged adjacent to each other, thereby increasing the amount of resin discharged from one nozzle.

[0012] Here, the resin nozzle has a first nozzle hole and a second nozzle hole, the first nozzle hole and the second nozzle hole are linear through holes, the first nozzle hole has: a first large diameter portion of a substantially cylindrical shape into which the molten polymer flows, and a first small diameter portion formed on the inner side of the first large diameter portion and having a smaller diameter than the first large diameter portion, the second nozzle hole has: a second large diameter portion of a substantially cylindrical shape into which the molten polymer flows, and a second small diameter portion formed on the inner side of the second large diameter portion and having a smaller diameter than the second large diameter portion, and the molten polymer can also be discharged from the front ends of the first small diameter portion and the second small diameter portion. Thus, the molten polymer can be stably flowed from the large diameter portion to the small diameter portion.

[0013] Here, the diameter of the first small diameter portion is larger than the diameter of the second small diameter portion. Thus, nanofibers with different diameters can be generated simultaneously.

[0014] Here, the value obtained by dividing the length of the first small diameter portion by the diameter of the first small diameter portion may be greater than the value obtained by dividing the length of the second small diameter portion by the diameter of the second small diameter portion. Thus, even if the diameter of the first small diameter portion is different from the diameter of the second small diameter portion, the molten polymer can be discharged from the first small diameter portion and the second small diameter portion in the same manner.

[0015] Here, the diameter of the first small diameter portion is substantially the same as the diameter of the second small diameter portion, and the length of the first small diameter portion is substantially the same as the length of the second small diameter portion. Thus, the production amount of nanofibers is doubled, and productivity can be improved.

[0016] Effects of the Invention

[0017] According to the present invention, the amount of resin discharged from one nozzle can be increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram which shows the outline of the melt-blowing device 1.

[0019] Figure 2 A perspective view schematically showing an enlarged portion of the meltblowing device 1.

[0020] Figure 3 1 is a diagram schematically showing the resin nozzle 14. Figure 3 (A) is a top view, Figure 3 (B) is a cross-sectional view.

[0021] Figure 4 1 is a diagram schematically showing a resin nozzle 14A. Figure 4 (A) is a top view, Figure 4 (B) is a cross-sectional view. DETAILED DESCRIPTION

[0022] The melt-blowing device of the present invention is a device for melting a thermoplastic resin and discharging it from the nozzle of an extruder to produce fibers (nanofibers) with a small fiber diameter by melt-blowing with high-speed and high-temperature airflow.

[0023] <First embodiment>

[0024] Figure 1 It is a schematic diagram which shows the outline of the melt-blowing device 1. Figure 2 A perspective view schematically showing an enlarged portion of a melt-blowing device 1. The melt-blowing device 1 mainly includes a resin supply unit 10, an air flow generating unit 20, and a collecting unit 30.

[0025] The resin supply unit 10 mainly includes a hopper 11, an extruder 12, a die 13, and a resin nozzle 14. A raw material sheet of a thermoplastic resin is put into the hopper 11, and the thermoplastic resin is melted by heating by a heater (not shown) provided in the extruder 12 to obtain a molten polymer. The extruder 12 pushes the molten polymer toward the die 13.

[0026] The resin nozzle 14 is provided at the mold 13 and discharges the molten polymer supplied from the mold 13. Figure 2 As shown, the resin nozzles 14 are arranged in a row. The molten polymer is discharged from the resin nozzles 14 from the top to the bottom. A plurality of nozzle holes are formed in each of the resin nozzles 14. The resin nozzles 14 will be described in detail later.

[0027] In the present embodiment, as the thermoplastic resin, for example, polypropylene (PP), polyterephthalate (PET), or polybutylene terephthalate (PBT) is used, but the present invention is not limited thereto.

[0028] The air flow generating unit 20 mainly includes a compressor 21 for generating compressed air, a pipe 22 through which the compressed air passes, a regulator 23, a heater 24 for heating the pipe 22, and an air nozzle 25. High-temperature air is generated by the compressor 21, the pipe 22, and the heater 24. The air nozzle 25 is provided adjacent to the resin nozzle 14, and discharges the generated high-temperature and high-pressure air.

[0029] like Figure 2 As shown, the air nozzles 25 are arranged in a row. The arrangement direction of the air nozzles 25 is substantially parallel to the arrangement direction of the resin nozzles 14 , and the arrangement region of the air nozzles 25 includes the arrangement region of the resin nozzles 14 .

[0030] High-temperature air is discharged in the horizontal direction from the air nozzle 25. By ejecting the air discharged from the air nozzle 25, the molten polymer discharged from the resin nozzle 14 is stretched to become a fibrous resin (nanofiber). In addition, by arranging the air nozzle 25 at a position intersecting with the central axis of the resin nozzle 14, the molten polymer falling by its own weight is placed in the air flow as early as possible, and the stretching effect caused by the air can be improved.

[0031] The collecting unit 30 mainly includes a substantially cylindrical suction drum 31 for collecting fibrous resin, a blower 32, a suction unit 33 connected to the blower 32, nonwoven fabric rolls 34 and 35 for winding nonwoven fabrics 51 and 52, and a winding drum 36. Here, the nonwoven fabric 51 is a base material, and the nonwoven fabric 52 is a covering material.

[0032] The air discharged from the air nozzle 25 has a large air volume (about 70 liters / minute) and a high wind speed, so a flow is generated by the air discharged from the air nozzle 25. Therefore, the molten polymer discharged from the resin nozzle 14 first rides on the flow and flows in the horizontal direction ( Figure 1 The resin (nanofibers) is blown out from the air nozzle 25 (to the right in the middle), and then the resin (nanofibers) is extended to form fibers by the air discharged from the air nozzle 25 (to the downstream side of the flow path of the air discharged from the air nozzle 25), and is sprayed onto the suction drum 31. The suction drum 31 winds up the nonwoven fabric 51 drawn out from the nonwoven fabric roll 34, and sucks air from the suction unit 33 so that the nanofibers are adsorbed on the surface of the nonwoven fabric 51.

[0033] One end of the nonwoven fabric 51 is placed on the winding drum 36. The winding drum 36 rotates at a constant speed, and the nonwoven fabric 51 with the nanofibers adsorbed on the surface moves toward the winding drum 36 at a constant speed.

[0034] In addition, one end of the nonwoven fabric 52 drawn out from the nonwoven fabric roll 35 is set on the winding drum 36. Therefore, the winding drum 36 rotates at a constant speed, so that the nonwoven fabric 52 covers the nanofiber layer on the surface of the nonwoven fabric 51. Moreover, the portion of the nanofiber layer on the surface of the nonwoven fabric 51 covered by the nonwoven fabric 52 through calendering and the like is integrated, thereby forming a finished product (cloth-like product) in which the nanofibers are clamped by the nonwoven fabrics 51 and 52, and is wound on the winding drum 36. This cloth-like product can be used as a filter material, for example. The filter material formed by the nanofibers being clamped by the nonwoven fabrics 51 and 52 has the advantages of high porosity and low ventilation resistance.

[0035] Next, the resin nozzle 14 will be described. Figure 3 1 is a diagram schematically showing the resin nozzle 14. Figure 3 (A) is a top view, Figure 3 (B) is a cross-sectional view. The central axis 14ax of the resin nozzle 14 is along a substantially vertical direction. Figure 3 In (B), the left side is the upper side in the vertical direction, and the right side is the lower side in the vertical direction.

[0036] The resin nozzle 14 has a flange 14a and a substantially cylindrical tubular portion 14b. The flange 14a is provided on the mold 13, and the front end of the tubular portion 14b (the side opposite to the side provided with the flange 14a) is exposed from the lower side of the mold 13.

[0037] The resin nozzle 14 has a first nozzle hole 141 and a second nozzle hole 145 as linear through holes. The first nozzle hole 141 and the second nozzle hole 145 are provided adjacent to each other. The first nozzle hole 141 and the second nozzle hole 145 are holes that penetrate the resin nozzle 14 in the vertical direction, and both sides are open at the upper surface 14c of the flange portion 14a and the lower surface 14d of the cylindrical portion 14b.

[0038] The base side of the resin nozzle 14 is the side close to the mold 13, and the tip side of the resin nozzle 14 is the side away from the mold 13. In other words, the flange 14a is provided on the base side of the resin nozzle 14.

[0039] The first nozzle hole 141 has a substantially cylindrical large diameter portion 142 and a substantially cylindrical small diameter portion 143. The large diameter portion 142 is formed on the root side of the resin nozzle 14, and one end is open to the surface 14c (here, the bottom surface of the hole 149). The small diameter portion 143 is formed on the inner side of the large diameter portion 142, and one end is open to one end of the large diameter portion 142, and the other end is open to the surface 14d.

[0040] In this embodiment, a hole 149 is provided in the surface 14c, and one end of the large diameter portion 142 opens at the bottom of the hole 149. However, the hole 149 is not essential, and the bottom of the hole 149 has the same meaning as the surface 14c.

[0041] When viewed from the base side (surface 14 c side) of the resin nozzle 14 , the side entering the resin nozzle 14 from the surface 14 c is referred to as the back side, and the surface 14 c side is referred to as the front side.

[0042] The diameter of the small diameter portion 143 The diameter of the small diameter portion 143 is smaller than that of the large diameter portion 142 and is as small as about 0.5 mm. The diameter of the small diameter portion 143 is larger than that of the small diameter portion 147 (described later) of the second nozzle hole 145 .

[0043] The molten polymer flows into the large diameter portion 142 from the end on the surface 14c side. The molten polymer flows toward the depth of the large diameter portion 142 and flows into the small diameter portion 143. The molten polymer that has flowed into the small diameter portion 143 is discharged from the end on the inner side of the small diameter portion 143, in other words, from the end opened at the surface 14d.

[0044] The second nozzle hole 145 has a substantially cylindrical large diameter portion 146 and a substantially cylindrical small diameter portion 147. The large diameter portion 146 is formed on the root side of the resin nozzle 14, and one end is open to the surface 14c. The small diameter portion 147 is formed on the inner side of the large diameter portion 146, and one end is open to the end of the large diameter portion 146, and the other end is open to the surface 14d.

[0045] The diameter of the small diameter portion 147 The diameter of the small diameter portion 147 is smaller than that of the large diameter portion 146, and its size is as small as 0.3 mm. The diameter of the small diameter portion 143 Small.

[0046] The molten polymer flows into the large diameter portion 146 from the end on the surface 14c side. The molten polymer flows toward the depth of the large diameter portion 146 and flows into the small diameter portion 147. The molten polymer that has flowed into the small diameter portion 147 is discharged from the end on the inner side of the small diameter portion 147, in other words, from the end opened on the surface 14d.

[0047] The central axis 14ax of the resin nozzle 14 is substantially vertical. Therefore, the central axis ax1 of the first nozzle hole 141 and the central axis ax2 of the second nozzle hole 145 are also substantially vertical, and the molten polymer discharged from the small diameter portions 143 and 147 falls vertically downward by its own weight.

[0048] The diameter of the small diameter portion 143 of the first nozzle hole 141 is The diameter of the small diameter portion 147 of the second nozzle hole 145 is Moreover, the length L1 of the small diameter portion 143 is divided by the diameter of the small diameter portion 143. The obtained value X1 is the length L2 of the small diameter portion 147 divided by the diameter of the small diameter portion 147 The obtained value X2 is large. Therefore, the diameter of the small diameter portion 143 and the diameter of the small diameter portion 147 In different cases, the molten polymer can be discharged from the small diameter portion 143 and the small diameter portion 147 in the same manner.

[0049] If the length L1 of the small diameter portion 143 is divided by the diameter of the small diameter portion 143, the The obtained value X1 is the length L2 of the small diameter portion 147 divided by the diameter of the small diameter portion 147. The obtained value X2 is expressed as the following formula (1).

[0050] [Formula 1]

[0051] (where A is a number greater than or equal to 1) (1)

[0052] If the values ​​X1 and X2 are too large, the pressure loss inside the first nozzle hole 141 is too large, so there is a possibility that the molten polymer will be ejected from the front end of the small diameter portion 143, and the molten polymer may be ejected discontinuously. Therefore, it is preferred to set the value X2 to about 4 to 6, and set the coefficient A to 3 or less (preferably, 2 to 3).

[0053] According to the present embodiment, since one resin nozzle 14 has two nozzle holes (the first nozzle hole 141 and the second nozzle hole 145 ), the amount of resin discharged from one resin nozzle 14 can be increased.

[0054] In addition, according to the present embodiment, since the diameter of the small diameter portion 143 of the first nozzle hole 141 is The diameter of the small diameter portion 147 of the second nozzle hole 145 is Different, thus nanofibers of different diameters can be generated simultaneously. Moreover, by using the finished product obtained by covering the nonwoven fabric 52 with nanofibers of different diameters mixed and adsorbed on the surface of the nonwoven fabric 51 as a filter material, the filtering performance, heat insulation performance, and sound absorption performance can be improved compared to the filter material only including nanofibers of the same diameter. In addition, since the finished product of the mixture of nanofibers of different diameters improves the heat insulation performance and sound absorption performance, the finished product can be used as a heat insulation material and a sound absorption material.

[0055] In addition, in the present embodiment, the bottom surface of the large diameter portion 142, 146 (the surface on the inner side (the side of the small diameter portion 143, 147)) is substantially orthogonal to the central axis ax1, ax2, but the shape of the bottom surface of the large diameter portion 142, 146 is not limited thereto. For example, the bottom surface of the large diameter portion 142, 146 may also be a tapered shape with a gradually tapered diameter so as not to hinder the flow of the molten polymer.

[0056] <Second embodiment>

[0057] In the first embodiment of the present invention, the first nozzle hole 141 and the second nozzle hole 145 having different diameters are provided in the resin nozzle 14, but the first nozzle hole and the second nozzle hole of the resin nozzle are not limited thereto. The second embodiment of the present invention is a method in which the resin nozzle has two identical nozzle holes. The meltblowing device related to the second embodiment is described below.

[0058] The difference between the meltblowing device 1 related to the first embodiment and the meltblowing device related to the second embodiment is only the resin nozzle, and the other structures are the same. Therefore, below, only the resin nozzle 14A of the meltblowing device related to the second embodiment is described, and the description of other parts is omitted. In addition, the same symbols are given to the same parts as the first embodiment, and the description is omitted.

[0059] Figure 4 1 is a diagram schematically showing a resin nozzle 14A. Figure 4 (A) is a top view, Figure 4 (B) is a cross-sectional view. The central axis 14ax of the resin nozzle 14A is along a substantially vertical direction. Figure 4 In (B), the left side is the upper side in the vertical direction, and the right side is the lower side in the vertical direction.

[0060] The resin nozzle 14A has a flange portion 14a and a substantially cylindrical tubular portion 14b. The resin nozzle 14A also has a first nozzle hole 141A and a second nozzle hole 145A, which are linear through holes.

[0061] The first nozzle hole 141A and the second nozzle hole 145A are provided adjacent to each other. The first nozzle hole 141A and the second nozzle hole 145A are holes penetrating the resin nozzle 14A in the vertical direction, and both sides are open on the surface 14c and the surface 14d.

[0062] The first nozzle hole 141A has a substantially cylindrical large diameter portion 142A and a substantially cylindrical small diameter portion 143A. The large diameter portion 142A is formed on the root side of the resin nozzle 14, and one end is open to the surface 14c. The small diameter portion 143A is formed on the inner side of the large diameter portion 142, and one end is open to the end of the large diameter portion 142A, and the other end is open to the surface 14d.

[0063] The second nozzle hole 145A has a substantially cylindrical large diameter portion 146A and a substantially cylindrical small diameter portion 147A. The large diameter portion 146A is formed on the root side of the resin nozzle 14A, and one end is open to the surface 14c. The small diameter portion 147A is formed on the inner side of the large diameter portion 146A, and one end is open to the end of the large diameter portion 146A, and the other end is open to the surface 14d.

[0064] The diameter of the small diameter parts 143A and 147A The diameter of the small diameter portion 143A is smaller than that of the large diameter portion 142A and 146A. and the diameter of the small diameter portion 147A They are roughly the same, with a size of about 0.3 mm.

[0065] In the large diameter parts 142A and 146A, the molten polymer flows in from the end on the side of the surface 14c. The molten polymer flows toward the depth of the large diameter parts 142A and 146A, and flows into the small diameter parts 143A and 147A. The molten polymer flowing into the small diameter parts 143A and 147A is discharged from the end on the side of the surface 14d. The central axis ax1 of the first nozzle hole 141A and the central axis ax2 of the second nozzle hole 145A are along the substantially vertical direction, and the molten polymer discharged from the small diameter parts 143A and 147A falls vertically downward by its own weight.

[0066] The diameter of the small diameter portion 143A of the first nozzle hole 141A is The diameter of the small diameter portion 147A of the second nozzle hole 145A is The length L3 of the small diameter portion 143A is substantially the same as the length L3 of the small diameter portion 147A. Therefore, the molten polymer can be discharged from the small diameter portion 143A and the small diameter portion 147A under the same conditions.

[0067] According to the present embodiment, one resin nozzle 14A has two nozzle holes (the first nozzle hole 141A and the second nozzle hole 145A), so that the amount of resin discharged from one resin nozzle 14A can be increased. and the diameter of the small diameter portion 147A By setting the ratio to be substantially the same, the production amount of nanofibers can be doubled, thereby improving productivity.

[0068] In addition, in the first and second embodiments, the resin nozzle has two nozzle holes (a first nozzle hole and a second nozzle hole), but the number of nozzle holes of the resin nozzle is not limited to two. The resin nozzle only needs to have a plurality of nozzle holes arranged adjacent to each other, and the number of nozzle holes may be three or more. For example, three nozzle holes can be considered as a combination of two nozzle holes. In addition, for example, the resin nozzle may also have two first nozzle holes 141A and a second nozzle hole 145A having a different diameter from the first nozzle hole 141A, or the first nozzle hole 141A and the second nozzle hole 145A may each have two.

[0069] In the first and second embodiments, the air nozzle 25 is provided to discharge high-temperature air horizontally, but the air nozzle 25 is not limited thereto. For example, the air nozzle 25 to discharge high-temperature air vertically downward may be provided adjacent to the resin nozzle 14 in the mold 13 .

[0070] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the specific structure is not limited to the embodiments, and also includes design changes within the scope of the gist of the invention. For example, the above-mentioned embodiments are described in detail to facilitate the understanding of the present invention, and are not necessarily limited to the case where all the structures described are provided. In addition, a part of the structure of the embodiment can be replaced with the structure of other embodiments, and in addition, other structures can be added, deleted, replaced, etc. in the structure of the embodiment.

[0071] In addition, in the present invention, the so-called "substantially" strictly speaking does not only include the same situation, but also includes the concept of error and deformation to the extent that the sameness is not lost. For example, the so-called "substantially vertical direction" is strictly speaking not limited to the situation of the vertical direction, but also includes the concept of error of several degrees. In addition, for example, in the case of being orthogonal, parallel, consistent, etc., strictly speaking, it includes not only the situation of orthogonal, parallel, consistent, etc., but also the situation of approximately parallel, approximately orthogonal, approximately consistent, etc.

[0072] In addition, the term "near" in the present invention means an area of ​​a certain range (which can be arbitrarily defined) near the reference position. For example, in the case of the so-called near the end, it is an area of ​​a certain range near the end and may or may not include the end.

[0073] Explanation of symbols

[0074] 1: Meltblown device

[0075] 10: Resin supply unit

[0076] 11: Hopper

[0077] 12: Extrusion machine

[0078] 13: Mould

[0079] 14, 14A: Resin nozzle

[0080] 14a: Flange

[0081] 14ax: Central axis

[0082] 14b: Cylindrical part

[0083] 14c, 14d: Surface

[0084] 20: Air flow generating part

[0085] 21: Compressor

[0086] 22: Piping

[0087] 23: Regulator

[0088] 24: Heater

[0089] 25: Air nozzle

[0090] 30: Collection department

[0091] 31: Suction drum

[0092] 32 : Blower

[0093] 33: Attraction

[0094] 34, 35: Non-woven fabric rolls

[0095] 36: Winding drum

[0096] 51, 52: Non-woven fabric

[0097] 141, 141A: first nozzle hole

[0098] 142, 142A: Large diameter part

[0099] 143, 143A: Small diameter

[0100] 145, 145A: Second nozzle hole

[0101] 146, 146A: Large diameter part

[0102] 147, 147A: Small diameter

[0103] 149: Kong.

Claims

1. A melt-blowing device, characterized in that: have: Multiple resin nozzles to discharge molten polymer; The air flow generating section comprises: a high temperature air generating section for generating high temperature air; and an air nozzle disposed adjacent to the resin nozzle for discharging the high temperature air generated by the high temperature air generating section; a collecting section for collecting fibrous resin generated by the molten polymer being stretched by the air discharged from the air nozzle, A plurality of the resin nozzles are arranged in a row, The resin nozzle has a first nozzle hole and a second nozzle hole which are respectively arranged adjacent to each other. The first nozzle hole and the second nozzle hole are linear through holes. The first nozzle hole has: a first large diameter portion of a substantially cylindrical shape into which the molten polymer flows; and a first small diameter portion formed on the inner side of the first large diameter portion and having a diameter smaller than that of the first large diameter portion. The second nozzle hole has: a second large diameter portion of a substantially cylindrical shape into which the molten polymer flows; and a second small diameter portion formed on the inner side of the second large diameter portion and having a diameter smaller than that of the second large diameter portion. The molten polymer is discharged from the front ends of the first small diameter portion and the second small diameter portion. In order to make the molten polymer discharge from the first small diameter portion and the second small diameter portion in the same manner, the diameter of the first small diameter portion is larger than the diameter of the second small diameter portion, and the value obtained by dividing the length of the first small diameter portion by the diameter of the first small diameter portion is larger than the value obtained by dividing the length of the second small diameter portion by the diameter of the second small diameter portion.

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