JP2021038492A - Melt blow device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a melt blow device capable of increasing the amount of resin discharged from one nozzle. SOLUTION: A plurality of resin nozzles 14 for discharging a molten polymer, a high temperature air generating section for generating high temperature air, and a high temperature air generating section provided adjacent to the resin nozzle 14 and having a high temperature generated by the high temperature air generating section are provided. It includes an air flow generating unit 20 having an air nozzle 25 for discharging air, and a collecting unit 30 for collecting the fibrous resin generated by stretching the molten polymer with the air discharged from the air nozzle 25. .. The plurality of resin nozzles 14 are provided side by side in a row, and each has a plurality of nozzle holes provided adjacent to each other. [Selection diagram] Fig. 1

Description

The present invention relates to a melt blow device.

Patent Document 1 discloses an ultrafine fiber generating apparatus in which a plurality of nozzles are provided side by side in a row.

Patent No. 6187925

However, in the invention described in Patent Document 1, only one nozzle hole is formed in one nozzle, and Patent Document 1 discloses a problem of increasing the amount of resin discharged from one nozzle. Not.

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

In order to solve the above problems, the melt blow device according to the present invention is provided, for example, with a plurality of resin nozzles for discharging a molten polymer, a high temperature air generating unit for generating high temperature air, and adjacent to the resin nozzles. An air flow generating portion having an air nozzle for discharging high temperature air generated by the high temperature air generating portion, and a fibrous fibrous product produced by stretching the molten polymer with the air discharged from the air nozzle. A collection unit for collecting resin, and a plurality of the resin nozzles are provided side by side in a row, and each of the resin nozzles has a plurality of nozzle holes provided adjacent to each other. It is a feature.

According to the melt blow device according to the present invention, the plurality of resin nozzles provided side by side in a row each have a plurality of nozzle holes provided adjacent to each other. This makes it possible to increase the amount of resin discharged from one nozzle.

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, and the first nozzle hole is the said. A substantially cylindrical first large-diameter portion into which the molten polymer flows, and a first small-diameter portion formed behind the first large-diameter portion and having a diameter smaller than the diameter of the first large-diameter portion. The second nozzle hole has a substantially cylindrical second large diameter portion into which the molten polymer flows, and is formed on the inner side of the second large diameter portion, and has a diameter of the second large diameter portion. It has a second small diameter portion having a smaller diameter, and the molten polymer may be discharged from the tips of the first small diameter portion and the second small diameter portion. As a result, the molten polymer can be stably flowed from the large diameter portion to the small diameter portion.

Here, the diameter of the first small diameter portion may be larger than the diameter of the second small diameter portion. This makes it possible to simultaneously produce nanofibers of different diameters.

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 larger than the value obtained by dividing the length of the second small diameter portion by the diameter of the second small diameter portion. .. As a result, even when the diameter of the first small diameter portion and the diameter of the second small diameter portion are different, the molten polymer can be similarly discharged from the first small diameter portion and the second small diameter portion.

Here, the diameter of the first small diameter portion and the diameter of the second small diameter portion may be substantially the same, and the length of the first small diameter portion and the length of the second small diameter portion may be substantially the same. As a result, the production amount of nanofibers can be doubled and the productivity can be improved.

According to the present invention, the amount of resin discharged from one nozzle can be increased.

It is a schematic diagram which shows the outline of the melt blow device 1. It is a perspective view which showed the part of the melt blow device 1 enlarged and schematically. It is a figure which shows the outline of the resin nozzle 14, (A) is a plan view, (B) is a sectional view. It is a figure which shows the outline of the resin nozzle 14A, (A) is a plan view, (B) is a sectional view.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The melt blow device of the present invention is a device used for producing fibers (nanofibers) having a small fiber diameter by a melt blow method in which a thermoplastic resin is melted and discharged from a nozzle of an extruder and blown out by a high-speed high-temperature airflow. is there.

<First Embodiment>
FIG. 1 is a schematic view showing an outline of the melt blow device 1. FIG. 2 is an enlarged perspective view of a part of the melt blow device 1. The melt blow device 1 mainly includes a resin supply unit 10, an air flow generation unit 20, and a collection unit 30.

The resin supply unit 10 mainly includes a hopper 11, an extruder 12, a die 13, and a resin nozzle 14. The raw material chips of the thermoplastic resin are put into the hopper 11 and heated by a heater (not shown) provided in the extruder 12 to melt the thermoplastic resin to obtain a molten polymer. The extruder 12 pushes the molten polymer into the die 13.

The resin nozzle 14 is provided on the die 13 and discharges the molten polymer supplied from the die 13. As shown in FIG. 2, the resin nozzles 14 are provided side by side in a row. The molten polymer is discharged from the resin nozzle 14 from above to below. A plurality of nozzle holes are formed in each of the resin nozzles 14. The resin nozzle 14 will be described in detail later.

In the present embodiment, for example, polypropylene (PP), polyethylene terephthalate (PET), and polybutylene terephthalate (PBT) are used as the thermoplastic plastic resin, but the present invention is not limited thereto.

The air flow generating unit 20 mainly includes a compressor 21 that generates compressed air, a pipe 22 through which compressed air passes, a regulator 23, a heater 24 that heats 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.

As shown in FIG. 2, the air nozzles 25 are provided side by side 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 area of the air nozzles 25 includes the arrangement area of the resin nozzles 14.

High temperature air is discharged in the horizontal direction from the air nozzle 25. By blowing 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). Further, by arranging the air nozzle 25 at a position intersecting the central axis of the resin nozzle 14, the molten polymer that falls by its own weight can be placed on the air flow at the earliest possible stage, and the effect of stretching by air can be enhanced.

The collecting portion 30 is mainly a suction drum 31 having a substantially cylindrical shape for collecting fibrous resin, a blower 32, a suction portion 33 connected to the blower 32, and a non-woven fabric around which the non-woven fabrics 51 and 52 are wound. It has rolls 34 and 35 and a take-up drum 36. Here, the non-woven fabric 51 is a base material, and the non-woven fabric 52 is a cover material.

Since the air discharged from the air nozzle 25 has a large air volume (about 70 liters / minute) and the wind speed is high, the air discharged from the air nozzle 25 generates an accompanying flow. Therefore, the molten polymer discharged from the resin nozzle 14 is first blown off in the horizontal direction (right direction in FIG. 1) by the accompanying flow, and then forward (air discharged from the air nozzle 25) by the air discharged from the air nozzle 25. By being blown off to the downstream side of the flow), it is stretched to become a fibrous resin (nanofiber), which is sprayed onto the suction drum 31. The non-woven fabric 51 drawn from the non-woven fabric roll 34 is wound around the suction drum 31, and the nanofibers are adsorbed on the surface of the non-woven fabric 51 by sucking air from the suction unit 33.

The end of the non-woven fabric 51 is provided on the take-up drum 36. As the take-up drum 36 rotates at a constant speed, the non-woven fabric 51 on which the nanofibers are adsorbed on the surface moves toward the take-up drum 36 at a constant speed.

Further, the non-woven fabric 52 drawn from the non-woven fabric roll 35 is also provided at the end of the take-up drum 36. Therefore, when the take-up drum 36 rotates at a constant speed, the non-woven fabric 52 covers the nanofiber layer on the surface of the non-woven fabric 51. Then, by integrating the non-woven fabric 52 covering the nanofiber layer on the surface of the non-woven fabric 51 by calendar processing or the like, the nanofibers become a finished product (cloth-like product) sandwiched between the non-woven fabrics 51 and 52 and wound up. It is wound around the drum 36. This cloth-like product can be used, for example, as a filter medium. The filter medium formed by sandwiching the nanofibers with the nonwoven fabrics 51 and 52 has the advantages of high porosity and low ventilation resistance.

Next, the resin nozzle 14 will be described. 3A and 3B are views showing an outline of the resin nozzle 14, where FIG. 3A is a plan view and FIG. 3B is a cross-sectional view. The central axis 14ax of the resin nozzle 14 is substantially in the vertical direction, and in FIG. 3B, the left side is the upper side in the vertical direction and the right side is the lower side in the vertical direction.

The resin nozzle 14 has a flange portion 14a and a substantially cylindrical tubular portion 14b. The flange portion 14a is provided on the die 13, and the tip of the tubular portion 14b (the side opposite to the side on which the flange portion 14a is provided) is exposed from the lower side of the die 13.

The resin nozzle 14 has a first nozzle hole 141 and a second nozzle hole 145, which are 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 are open on both sides to the upper surface 14c of the flange portion 14a and the lower surface 14d of the tubular portion 14b. To do.

The root side of the resin nozzle 14 is the side close to the die 13 of the resin nozzle 14, and the tip side of the resin nozzle 14 is the side far from the die 13 of the resin nozzle 14. That is, the flange portion 14a is provided on the root side of the resin nozzle 14.

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 thereof 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, one end of which is open to the end of the large diameter portion 142, and the other end of which is open to the surface 14d.

In the present embodiment, the surface 14c is provided with a hole 149, and one end of the large diameter portion 142 is opened to the bottom surface of the hole 149, but the hole 149 is not essential, and the bottom surface and the surface 14c of the hole 149 are formed. Is synonymous.

When viewed from the root side (surface 14c side) of the resin nozzle 14, the side that enters the resin nozzle 14 from the surface 14c is the back side, and the surface 14c side is the front side.

The diameter φ1 of the small diameter portion 143 is smaller than the diameter of the large diameter portion 142, and its size is considerably small, about 0.5 mm. However, the diameter of the small diameter portion 143 is larger than the diameter of the small diameter portion 147 (detailed later) of the second nozzle hole 145.

The molten polymer flows into the large diameter portion 142 from the end on the surface 14c side. The molten polymer flows toward the back 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 inner end of the small diameter portion 143, that is, the end that is open to the surface 14d.

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 thereof is open to the surface 14c. The small diameter portion 147 is formed on the inner side of the large diameter portion 146, one end of which is open to the end of the large diameter portion 146, and the other end of which is open to the surface 14d.

The diameter φ2 of the small diameter portion 147 is smaller than the diameter of the large diameter portion 146, and its size is considerably small, about 0.3 mm. Further, the diameter φ2 of the small diameter portion 147 is smaller than the diameter φ1 of the small diameter portion 143.

The molten polymer flows into the large diameter portion 146 from the end on the surface 14c side. The molten polymer flows toward the back 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 inner end of the small diameter portion 147, that is, the end that is open to the surface 14d.

The central axis 14ax of the resin nozzle 14 is substantially in the vertical direction. 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 vertically aligned, and the molten polymer discharged from the small diameter portions 143 and 147 falls vertically downward due to its own weight. To do.

The diameter φ1 of the small diameter portion 143 of the first nozzle hole 141 is larger than the diameter φ2 of the small diameter portion 147 of the second nozzle hole 145. The value X1 obtained by dividing the length L1 of the small diameter portion 143 by the diameter φ1 of the small diameter portion 143 is larger than the value X2 obtained by dividing the length L2 of the small diameter portion 147 by the diameter φ2 of the small diameter portion 147. Therefore, even when the diameter φ1 of the small diameter portion 143 and the diameter φ2 of the small diameter portion 147 are different, the molten polymer can be similarly discharged from the small diameter portion 143 and the small diameter portion 147.

The following mathematical expression shows that the value X1 obtained by dividing the length L1 of the small diameter portion 143 by the diameter φ1 of the small diameter portion 143 is larger than the value X2 obtained by dividing the length L2 of the small diameter portion 147 by the diameter φ2 of the small diameter portion 147. It becomes like the formula (1) of.
[Number 1]
X1 = A x (φ1 / φ2) x X2 (however, A is a number of 1 or more) ... (1)

If the values X1 and X2 are too large, the molten polymer may not be ejected from the tip of the small diameter portion 143 or the molten polymer may be ejected discontinuously due to excessive pressure loss inside the first nozzle hole 141. .. Therefore, it is desirable that the value X2 is about 4 to 6 and the coefficient A is 3 or less (preferably about 2 to 3).

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

Further, according to the present embodiment, since the diameter φ1 of the small diameter portion 143 of the first nozzle hole 141 and the diameter φ2 of the small diameter portion 147 of the second nozzle hole 145 are different, nanofibers having different diameters are simultaneously generated. be able to. Then, by using the finished product in which the non-woven fabric 51 in which nanofibers having different diameters are mixed and adsorbed on the surface is covered with the non-woven fabric 52 as a filter medium, the filtration performance and the heat insulating performance are compared with the filter medium containing only the nanofibers having the same diameter. , Sound absorption performance can be improved. Further, since the finished product in which nanofibers having different diameters are mixed has improved heat insulating performance and sound absorbing performance, this finished product can be used as a heat insulating material and a soundproofing material.

In the present embodiment, the bottom surface of the large diameter portions 142 and 146 (the surface on the back side (small diameter portions 143 and 147 sides)) is substantially orthogonal to the central axes ax1 and ax2, but the large diameter portions 142 and 146. The shape of the bottom surface of is not limited to this. For example, the bottom surface of the large diameter portions 142 and 146 may have a tapered shape in which the diameter gradually decreases so as not to obstruct the flow of the molten polymer.

<Second embodiment>
In the first embodiment of the present invention, the resin nozzle 14 is provided with the first nozzle hole 141 and the second nozzle hole 145 having different diameters, but the first nozzle hole and the second nozzle hole of the resin nozzle have. The form is not limited to this. A second embodiment of the present invention is a form in which the resin nozzle has two identical nozzle holes. Hereinafter, the melt blow device according to the second embodiment will be described.

The difference between the melt blow device 1 according to the first embodiment and the melt blow device according to the second embodiment is only the resin nozzle, and the other configurations are the same. Therefore, hereinafter, only the resin nozzle 14A of the melt blow device according to the second embodiment will be described, and the description of other parts will be omitted. Further, the same parts as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

4A and 4B are views showing an outline of the resin nozzle 14A, where FIG. 4A is a plan view and FIG. 4B is a cross-sectional view. The central axis 14ax of the resin nozzle 14A is substantially in the vertical direction, and in FIG. 4B, the left side is the upper side in the vertical direction and the right side is the lower side in the vertical direction.

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

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 that penetrate the resin nozzle 14A in the vertical direction, and both sides open to the surfaces 14c and 14d.

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 thereof is open to the surface 14c. The small diameter portion 143A is formed on the inner side of the large diameter portion 142, one end of which is open to the end of the large diameter portion 142A, and the other end of which is open to the surface 14d.

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 thereof is open to the surface 14c. The small diameter portion 147A is formed on the inner side of the large diameter portion 146A, one end of which is open to the end of the large diameter portion 146A, and the other end of which is open to the surface 14d.

The diameter φ3 of the small diameter portions 143A and 147A is smaller than the diameter of the large diameter portions 142A and 146A, respectively. The diameter φ3 of the small diameter portion 143A and the diameter φ3 of the small diameter portion 147A are substantially the same, and the size thereof is about 0.3 mm.

The molten polymer flows into the large diameter portions 142A and 146A from the end on the surface 14c side, respectively. The molten polymer flows toward the back of the large diameter portions 142A and 146A, respectively, and flows into the small diameter portions 143A and 147A, respectively. The molten polymer that has flowed into the small diameter portions 143A and 147A is discharged from the end on the surface 14d side, respectively. The central axis ax1 of the first nozzle hole 141A and the central axis ax2 of the second nozzle hole 145A are substantially vertically aligned, and the molten polymer discharged from the small diameter portions 143A and 147A falls vertically downward by its own weight.

The diameter φ3 of the small diameter portion 143A of the first nozzle hole 141A and the diameter φ3 of the small diameter portion 147A of the second nozzle hole 145A are substantially the same, and the length L3 of the small diameter portion 143A and the length L3 of the small diameter portion 147A are abbreviated. It is the same. Therefore, the molten polymer can be discharged from the small diameter portion 143A and the small diameter portion 147A under the same conditions.

According to the present embodiment, since one resin nozzle 14A has two nozzle holes (first nozzle hole 141A and second nozzle hole 145A), the amount of resin discharged from one resin nozzle 14A is increased. be able to. Further, by making the diameter φ13 of the small diameter portion 143A and the diameter φ3 of the small diameter portion 147A substantially the same, the production amount of the nanofiber can be doubled and the productivity can be improved.

In the first and second embodiments, the resin nozzle has two nozzle holes (first nozzle hole and second nozzle hole), but the number of nozzle holes possessed by the resin nozzle is not limited to two. .. The resin nozzle may have a plurality of nozzle holes provided adjacent to each other, and the number of nozzle holes may be three or more. For example, the three nozzle holes can be thought of as a combination of two nozzle holes. Further, for example, the resin nozzle may have two first nozzle holes 141A and a second nozzle hole 145A having a diameter different from that of the first nozzle hole 141A, or the first nozzle hole 141A and the second nozzle hole. You may have two 145A each.

Further, in the first and second embodiments, the air nozzle 25 for discharging high temperature air in the horizontal direction is provided, but the form of the air nozzle 25 is not limited to this. For example, an air nozzle 25 for discharging high-temperature air vertically downward may be provided on the die 13 so as to be adjacent to the resin nozzle 14.

Although the embodiment of the present invention has been described in detail with reference to the drawings, the specific configuration is not limited to this embodiment and includes design changes and the like within a range not deviating from the gist of the present invention. .. For example, the above-described embodiment has been described in detail in order to explain the present invention in an easy-to-understand manner, and is not necessarily limited to those having all the described configurations. Further, it is possible to replace a part of the configuration of the embodiment with the configuration of another embodiment, and it is possible to add, delete, replace, or the like with another configuration to the configuration of the embodiment.

Further, in the present invention, the "abbreviation" is a concept including not only the case where the identity is exactly the same but also an error or deformation to the extent that the identity is not lost. For example, the "substantially vertical direction" is not limited to the case of a strictly vertical direction, and is a concept including an error of, for example, several degrees. Further, for example, in the case of simply expressing orthogonality, parallelism, coincidence, etc., not only the case of strictly orthogonality, parallelism, coincidence, etc., but also the case of substantially parallelism, substantially orthogonality, substantially coincidence, etc. shall be included.

Further, in the present invention, the "neighborhood" means to include a region of a certain range (which can be arbitrarily determined) near the reference position. For example, in the case of the vicinity of an edge, it is a concept indicating that it is a region of a certain range near the edge and may or may not include the edge.

1: Melt blow device 10: Resin supply part 11: Hopper 12: Extruder 13: Die 14, 14A: Resin nozzle 14a: Flange part 14ax: Central shaft 14b: Cylindrical part 14c, 14d: Surface 20: Air flow generation part 21 : Compressor 22: Piping 23: Regulator 24: Heater 25: Air nozzle 30: Collection section 31: Suction drum 32: Blower 33: Suction section 34, 35: Non-woven fabric roll 36: Winding drum 51, 52: Non-woven fabric 141, 141A: First nozzle holes 142, 142A: Large diameter portion 143, 143A: Small diameter portion 145, 145A: Second nozzle hole 146, 146A: Large diameter portion 147, 147A: Small diameter portion 149: Hole

Claims (5)

Multiple resin nozzles that eject molten polymer,
An air flow generating unit having a high-temperature air generating unit that generates high-temperature air and an air nozzle that is provided adjacent to the resin nozzle and discharges high-temperature air generated by the high-temperature air generating unit.
A collection unit that collects the fibrous resin produced by stretching the molten polymer with the air discharged from the air nozzle, and
With
The plurality of resin nozzles are provided side by side in a row.
A melt blow device, wherein each of the resin nozzles has a plurality of nozzle holes provided adjacent to each other. The resin nozzle has a first nozzle hole and a second nozzle hole, and 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 is formed in a substantially cylindrical first large-diameter portion into which the molten polymer flows and on the inner side of the first large-diameter portion, and has a diameter larger than the diameter of the first large-diameter portion. It has a small first small diameter part and
The second nozzle hole is formed in a substantially cylindrical second large-diameter portion into which the molten polymer flows and on the inner side of the second large-diameter portion, and has a diameter larger than the diameter of the second large-diameter portion. With a small second small diameter part,
The melt blow device according to claim 1, wherein the molten polymer is discharged from the tips of the first small diameter portion and the second small diameter portion. The melt blow device according to claim 2, wherein the diameter of the first small diameter portion is larger than the diameter of the second small diameter portion. A claim characterized in that 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. Item 3. The melt blow device according to item 3. The diameter of the first small diameter portion and the diameter of the second small diameter portion are substantially the same.
The melt blow device according to claim 2, wherein the length of the first small diameter portion and the length of the second small diameter portion are substantially the same.

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