JP6171072B1 - Resin fiber manufacturing method, nozzle head and manufacturing apparatus used therefor - Google Patents

Abstract

The present invention provides a method for manufacturing a resin fiber capable of increasing the production amount with high operability, and a nozzle head and a manufacturing apparatus used therefor. A method of manufacturing a resin fiber, which is an ultra-thin fiber obtained by stretching a thermoplastic resin with a high-pressure gas flow. The gas flow from the high-pressure gas jet port applies a negative pressure to the discharge port, and the molten resin inside the discharge port is drawn out and stretched to the outside while being stretched while the molten resin is cooled. The manufacturing apparatus includes an extruder for extruding molten resin from a nozzle at the tip of the barrel while melting the resin with a screw in the barrel, and a nozzle head attached to the tip of the nozzle. The nozzle head has a substantially vertical face surface. A discharge port for extruding the molten resin, and a high-pressure gas injection port that is provided in the vicinity of the discharge port so as to discharge the molten resin inside the discharge port to the outside while being drawn and extended to form a gas flow substantially horizontally, And the discharge port has a diameter of 0.5 mm or more. [Selection] Figure 2

Description

  The present invention relates to a method for producing a resin fiber, which is obtained by drawing an extruded thermoplastic resin with a high-pressure gas to form an aggregate of long fibers, and a nozzle head and a production apparatus used therefor, in particular, an ultra-fine length having a nano-order diameter. The present invention relates to a resin fiber manufacturing method, a manufacturing apparatus, and a nozzle head used therein.

  Resin fibers made of an aggregate of extra fine fibers having a diameter of several microns to submicrons are used as various filters and nonwoven fabrics. As a method for producing such a resin fiber, an electrospinning (electrospinning) method has been proposed for a long time, but a thermoplastic resin extruded from an extruder is blown with a high-pressure gas at a nozzle portion to be released into the air to produce a long fiber. In recent years, many researches have been made on the melt-blowing method for the assembly of these materials because of their high productivity and safety (see Non-Patent Document 1).

  For example, Patent Document 1 discloses a method for producing a resin fiber made of an aggregate of polypropylene extra long fibers by a melt blow method. In Example 2, the tip of the central discharge port through which the molten resin is extruded is wrapped with a hot air outlet, and stretched while maintaining the molten state of the resin in the hot air converging cylindrical portion extending downstream, and the resin is brought into the air from the opening. A collection of long fibers is collected at a collection part which is discharged and arranged in the horizontal direction. Here, the diameter of the central discharge port should be 0.1 to 0.2 mm, but since the molten state for stretching the resin is controlled by the hot air converging cylinder, the inner diameter and the internal temperature adjustment are performed. It is said that depending on the situation, it becomes impossible to discharge or only microfibers of micron order can be obtained.

  Furthermore, Patent Document 2 also discloses a method for producing a resin fiber made of an aggregate of thermoplastic resin extra-fine long fibers by a melt blow method. A plurality of small molten resin injection ports are provided around the widest diameter opening for injecting a gas heated to a temperature higher than the temperature of the molten resin to the outside of the apparatus in the horizontal direction, and the molten resin injected under pressure is a gas injection port It is supposed that it is drawn into the flow of gas injected from the largest diameter opening and injected to the outside of the apparatus and extended in the injection direction. Here, as one embodiment, the pressure is applied by reducing the tube diameter of 3 mm to 0.4 mm for the molten resin injection port, the gas is injected from the gas injection port of 2 mm diameter, and the maximum diameter opening of 22 mm diameter It is stated that gas is ejected from the outside of the apparatus.

Shinji Kunihiro, “The World of Nanofibers”, Electrical Functional Materials Industries Association, Electrical Materials Journal, No. 626, 2015.5-7, pp. 16-18

JP 2013-185272 A Japanese Unexamined Patent Publication No. 2016-23399

  In the manufacturing method of thermoplastic resin extra-fine long fibers by the melt blow method, the diameter is reduced by stretching the resin. The production amount can be increased with high operability by stably controlling the stretching process of the resin. In Patent Document 1, a hot air converging cylindrical portion is provided to block the stretching process from the outside. A high-temperature gas flow having a larger heat capacity than that of the first gas is formed, and resin is injected into the gas flow to block the outside from the outside.

  The present invention has been made in view of the situation as described above, and an object of the present invention is to provide a resin fiber manufacturing method capable of further greatly increasing the production amount with high operability, and a nozzle used therefor It is to provide a head and a manufacturing apparatus.

  A method for producing a resin fiber according to the present invention is a method for producing a resin fiber, which is an ultra-thin fiber in which a thermoplastic resin is drawn by a high-pressure gas flow, and a high-pressure resin in which a molten resin extruded from a discharge port is provided in the vicinity of the discharge port. In the method in which the gas flow from the gas jet port is given and discharged into the air and the molten resin is cooled and stretched, the gas flow from the high pressure gas jet port applies a negative pressure to the discharge port, and the discharge port The molten resin inside is drawn out to the outside and released into the air while being stretched.

  According to such an invention, the molten resin is drawn out and stretched to a very long fiber by a negative pressure due to the gas flow, but the operation is stabilized only by adjusting the gas flow corresponding to the extrusion amount of the resin, and high operability can be obtained. Since it is easy to increase the extrusion amount, the production amount can be further increased with high operability.

  In the above-described invention, the molten resin extruded from the discharge port is supplied from an extruder, and the molten resin remains inside the discharge port even when the supply of the molten resin from the extruder is stopped. May be drawn to the outside by a negative pressure and stretched. According to this invention, the molten resin can be surely drawn out and drawn into very long fibers by the negative pressure generated by the gas flow from the high-pressure gas outlet.

  In the above-described invention, the discharge port may have a diameter that reduces a flow resistance of the molten resin so that the molten resin can be drawn out by a negative pressure due to the gas flow. In the above-described invention, the diameter of the discharge port may be 0.5 mm or more. According to this invention, the molten resin can be reliably pulled out by the negative pressure due to the gas flow from the high-pressure gas jet port and can be drawn to the ultra-long fibers, and the production amount can be further increased.

  Furthermore, a resin fiber manufacturing apparatus according to the present invention is a resin fiber manufacturing apparatus that is an ultra-thin fiber obtained by stretching a thermoplastic resin with a high-pressure gas flow, and the barrel tip while melting the resin with a screw in the barrel. An extruder for extruding the molten resin from the nozzle of the nozzle, and a nozzle head attached to the tip of the nozzle, the nozzle head having a discharge port for extruding the molten resin on a substantially vertical face surface, and the discharge port A high-pressure gas outlet that is in the vicinity and forms a gas flow substantially horizontally, and the high-pressure gas outlet is provided so that the molten resin inside the discharge outlet is discharged to the outside while being drawn out and extended. It is located in the vicinity of the discharge port, and the diameter of the discharge port is 0.5 mm or more.

  According to such an invention, the molten resin can be drawn out and stretched to ultrafine fibers by a negative pressure due to the gas flow, and the operation is stabilized only by adjusting the amount of the gas flow according to the extrusion amount of the resin. It is possible to increase the production amount by increasing the extrusion amount.

  In the above-described invention, a plurality of pairs of the high-pressure gas ejection port and the ejection port may be provided on the face surface. In the above-described invention, the plurality of pairs may be provided on the face surface along a horizontal line. Furthermore, in the above-described invention, the plurality of pairs of the high-pressure gas jets may be provided so as to spread in a fan shape with their respective axes directed in the jet direction. According to this invention, the production amount can be further increased with high operability.

  Furthermore, the nozzle head according to the present invention is a resin fiber manufacturing apparatus that is an ultra-thin fiber in which a thermoplastic resin is drawn with a high-pressure gas flow, and melts the resin from the nozzle at the tip of the barrel while melting the resin with a screw in the barrel. A nozzle head that is attached to the tip of the nozzle and that extrudes the molten resin to a substantially vertical face when attached to the manufacturing apparatus; and the discharge port A high-pressure gas outlet that is in the vicinity and forms a gas flow substantially horizontally, and the high-pressure gas outlet is provided so that the molten resin inside the discharge outlet is discharged to the outside while being drawn out and extended. It is located in the vicinity of the discharge port, and the diameter of the discharge port is 0.5 mm or more.

  According to this invention, by attaching to a resin fiber manufacturing apparatus, the molten resin can be drawn out and drawn to ultra-long fibers with a negative pressure due to the gas flow, and the amount of gas flow is adjusted according to the amount of resin extrusion Just doing this will stabilize the operation and provide high operability. Further, the amount of extrusion can be increased to further increase the production amount.

  In the above-described invention, a plurality of pairs of the high-pressure gas ejection port and the ejection port may be provided on the face surface. In the invention described above, the plurality of pairs may be provided on the face surface along a horizontal line when attached to the manufacturing apparatus. Further, in the above-described invention, the plurality of pairs of the high-pressure gas jets may be provided so as to spread in a fan shape with their respective axes directed in the jet direction. According to this invention, the production amount can be further increased with high operability.

It is sectional drawing (partial block diagram) of the principal part of the manufacturing apparatus of the resin fiber in one Example by this invention. It is (a) front view and (b) side sectional drawing of a nozzle head. It is sectional drawing of a nozzle head. It is a SEM photograph of the resin fiber manufactured by the resin fiber manufacturing measure.

  A resin fiber manufacturing apparatus according to one embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 1, a resin fiber manufacturing apparatus 9 is a resin fiber manufacturing apparatus that is a very long fiber obtained by stretching a thermoplastic resin with a high-pressure gas flow, and an extruder 1 that extrudes molten resin from a nozzle 2a. And a nozzle head 10 attached to the tip of the nozzle 2a.

  The extruder 1 includes a barrel 2 and a screw 3 that heat and melt raw materials such as pellets made of a thermoplastic resin and convey them toward the nozzle 2a, and supply a raw material into the barrel 2 4 is provided. Moreover, the barrel 2 is provided with a heater 5 on its outer periphery, and can heat the inside. A nozzle head 10 for discharging resin is fixed to the tip of the nozzle 2a provided in the resin extrusion direction of the barrel 2. The nozzle head 10 is connected to the gas heating unit 7 by piping or the like, and is supplied after being heated with high-pressure gas supplied from a gas supply unit 6 such as a gas compressor connected to the nozzle head 10. . For example, the gas heating unit 7 may include a heating unit such as a heater around the gas pressure feeder.

  As shown in FIG. 2, the nozzle head 10 has an outer peripheral attachment portion 19 for attaching the nozzle head 10 to the extruder 1 and a main surface arranged substantially vertically when attached to the extruder 1 ( And a central face portion 11 (with the normal of the main surface oriented horizontally). The attachment portion 19 includes a bolt hole (not shown) for fixing the nozzle head 10 to the extruder 1. The face portion 11 is provided so as to protrude in the resin extrusion direction with respect to the attachment portion 19.

  The face portion 11 is provided with a discharge port 12 for discharging resin and a gas discharge port 13 for discharging high-pressure gas. The discharge port 12 and the gas ejection port 13 form a pair arranged one by one near each other. In this embodiment, a plurality of pairs of discharge ports 12 and gas jet ports 13 are provided, which is preferable because the production amount per unit time of the resin fiber can be improved.

  The discharge port 12 communicates with the resin inflow chamber 16. When the nozzle head 10 is attached to the extruder 1, the resin inflow chamber 16 is positioned in the resin extrusion direction with respect to the nozzle 2 a of the barrel 2, thereby forming a flow path for the molten resin supplied from the nozzle 2 a. The molten resin can be guided to the discharge port 12. The resin inflow chamber 16 is separated from the gas inflow chamber 14 serving as a gas flow path by a partition 15. The gas inflow chamber 14 is connected to the gas outlet 13 and is connected to an inflow port 14 a for high-pressure gas guided from the outside of the nozzle head 10. The inlet 14a is connected to the gas heating unit 7 described above. Thereby, the gas inflow chamber 14 can guide the inflowed high-pressure gas to the gas ejection port 13. Further, the gas outlet 13 is arranged so that its axis is substantially horizontal so that a gas flow is formed in a substantially horizontal direction by the high-pressure gas ejected. The discharge port 12 is also preferably arranged in a substantially horizontal direction in accordance with the direction of the gas jet port 13 that makes a pair.

  As described above, the gas outlet 13 is disposed in the vicinity of the discharge port 12. In particular, the gas ejection port 13 is close to the ejection port 12 so that the resin melted from the inside of the ejection port 12 can be drawn out by the negative pressure generated by the gas flow to be formed and can be discharged into the air while being stretched. Arranged. The discharge port 12 has an inner diameter so that the flow resistance of the molten resin is reduced and the resin is drawn out from the inside by a negative pressure due to the gas flow. The flow resistance of the molten resin decreases as the inner diameter increases. For example, the inner diameter of the outlet portion of the discharge port 12 (near the surface of the face portion 11) is preferably 0.5 mm or more. In the present embodiment, the inner diameter of the discharge port 12 is 1.0 mm, the inner diameter of the gas ejection port 13 is 1.5 mm, and the distance between the centers is 1.75 mm.

  Since the resin can be drawn out as described above, the gas outlet 13 can be arranged in any direction regardless of whether it is upward, downward, or lateral to the outlet 12. In the present embodiment, in the face portion 11, a pair in which the gas jets 13 are arranged below the discharge ports 12 is arranged in the upper stage, and a pair in which the gas jets 13 are arranged in the upper stage is arranged in the lower stage.

  As shown in FIG. 3, in a plurality of pairs of discharge ports 12 and gas outlets 13 arranged in the lower stage of the face portion 11, the axes of the gas outlets 13 are mutually aligned in the horizontal direction toward the ejection direction (upward in the drawing). It is provided so as to spread in a fan shape. For example, the axial lines of the gas outlets 13 at both ends overlap the two radii of a sector shape having a central angle α surrounded by two radii and an arc, and the axis lines of the other jet outlets 13 also intersect the two radii of the same sector shape. It is arranged to pass through the center point. Similarly, each axis of the discharge port 12 is provided so as to spread in a fan shape toward the discharge direction. By arranging in this way, it can be adjusted so as to suppress excessive entanglement between the resin fibers that are drawn out from each pair and released into the air, so the discharge amount per unit time of the resin can be increased, It is preferable because the production amount per unit time can be increased. The same applies to a plurality of pairs of discharge ports 12 and gas outlets 13 arranged in the upper stage of the face portion 11.

  In addition, since the other details of the extruder 1 are well-known, description is abbreviate | omitted. Moreover, the manufacturing apparatus 9 is appropriately provided with a collecting unit that collects the resin fibers to be discharged.

  Referring again to FIG. 1, when the resin fiber is manufactured by the manufacturing apparatus 9, the resin melted by the extruder 1 is supplied to the nozzle head 10 and discharged from the discharge port 12, while the gas supply unit 6 and the gas heating are performed. The high-pressure gas heated by the unit 7 is supplied to the nozzle head 10 and gas is ejected from the gas ejection port 13 to form a gas flow. As a result, the gas flow from the gas outlet 13 applies a negative pressure to the front side of the discharge port 12, draws the molten resin inside the discharge port 12 to the outside, and discharges the molten resin into the air while stretching it into ultra-long fibers. That is, a resin fiber can be manufactured by a kind of melt blow method in which molten resin is discharged into the air and stretched while being cooled. At this time, the operation can be easily stabilized by making the resin extrusion amount constant and adjusting the gas flow amount accordingly.

  In particular, even if the supply of the molten resin from the extruder 1 is stopped during the production of the resin fiber, the resin fiber is continuously produced for a while only by the supply of the high-pressure gas. That is, it can be seen that the resin remaining inside the discharge port 12 is reliably pulled out and stretched by the negative pressure due to the gas flow from the gas jet port 13.

  As shown in FIG. 4, it can be seen that the resin fiber manufactured by the manufacturing apparatus 9 is an extremely long fiber such as a so-called nanofiber having a diameter of about a few hundred nanometers. In addition, the resin fibers are appropriately entangled with each other, and almost no short-cut fibers or particulate resins are generated.

  As described above, according to the manufacturing apparatus 9, the melted resin in the discharge port 12 is drawn out by the negative pressure due to the gas flow from the gas jet port 13 and released into the air, and is drawn while being cooled, and is made of ultrafine fibers. A resin fiber can be manufactured. Since the resin is drawn out from the discharge port 12, the operation can be stabilized only by adjusting the amount of the gas flow according to the amount of the resin extruded from the extruder 1, and high operability can be obtained. As described above, even when the discharge amount of the resin is increased by arranging a plurality of pairs of the discharge ports 12 and the gas discharge ports 13 or the like, the amount of the gas flow may be adjusted according to this, and the productivity is high. The production volume can be further increased.

  Further, the manufacturing apparatus 9 can manufacture ultra-fine fibers such as nanofibers, but the inner diameter of the discharge port 12 is very large compared to the fiber diameter, and is set to 1 mm in the present embodiment as described above. That is, the diameter of the resin fiber manufactured by the manufacturing apparatus 9 is not dependent on the diameter of the discharge port 12 but is considered to depend on the balance between the gas flow from the ejection port 13 and the amount of resin supplied. It is done. That is, by adjusting the amount of gas flow according to the amount of molten resin supplied, the flow velocity and negative pressure from the jet nozzle 13 are adjusted. It is considered that the amount of the resin drawn out is adjusted by this, and the diameter is adjusted in relation to the flow rate of the gas flow. By balancing the amount of gas flow in accordance with the amount of molten resin that is supplied, it is possible to produce ultrafine fibers having a desired diameter. For this reason, it is preferable that the diameter of the discharge port 12 be relatively large so that the flow resistance of the molten resin is reduced to facilitate the drawing of the molten resin as described above. It is also easy to increase the production volume per unit time by increasing the discharge amount of the resin by adjusting the diameter of the discharge port 12 and adjusting the gas flow amount accordingly. It is.

  In addition, since the diameter of the discharge port 12 is large, there is little clogging and maintenance is also very easy.

  Further, the number of pairs of discharge ports 12 and gas outlets 13 of the nozzle head 10 is further increased, and for example, the production amount per unit time is further increased by providing three or more rows of pairs in the face portion 11. It can also be made.

  As mentioned above, although the Example by this invention and the modification based on this were demonstrated, this invention is not necessarily limited to these examples. In addition, those skilled in the art will be able to find various alternative embodiments and modifications without departing from the spirit of the present invention or the scope of the appended claims.

10 Nozzle head 11 Face 12 Discharge port 13 Gas outlet

Claims (10)

A method for producing a resin fiber, which is an ultrafine fiber that stretches a thermoplastic resin with a high-pressure gas flow,
Gas flow to release said molten resin inside the discharge port by applying a negative pressure to the discharge port in the air while the drawer extends to the outside from the high-pressure gas ejection port formed in a discharge opening neighborhood of the molten resin is extruded A method for producing a resin fiber characterized by the above.   The molten resin extruded from the discharge port is supplied from an extruder, and the molten resin remaining inside the discharge port is externally applied by negative pressure even when the supply of the molten resin from the extruder is stopped. The method for producing a resin fiber according to claim 1, wherein the resin fiber is drawn and drawn.   The method for producing a resin fiber according to claim 1 or 2, wherein the discharge port has a diameter that reduces a flow resistance of the molten resin so that the molten resin can be drawn out by a negative pressure due to the gas flow.   The method for producing a resin fiber according to claim 3, wherein the diameter of the discharge port is 0.5 mm or more. An apparatus for producing a resin fiber, which is a very long fiber that stretches a thermoplastic resin with a high-pressure gas flow,
An extruder for extruding the molten resin from the nozzle at the tip of the barrel while melting the resin with a screw in the barrel;
A nozzle head attached to the tip of the nozzle,
The nozzle head has a substantially vertical face surface.
A discharge port for extruding the molten resin;
A pair of high-pressure gas jets that form a gas flow substantially horizontally in the vicinity of the discharge port, and are given a plurality of pairs ,
The high-pressure gas outlet is positioned in the vicinity of the outlet, and the diameter of the outlet is 0.5 mm or more so that the molten resin inside the outlet is drawn out and released into the air while being stretched. A resin fiber manufacturing apparatus. 6. The resin fiber manufacturing apparatus according to claim 5, wherein the plurality of pairs are provided on the face surface along a horizontal line. 7. The apparatus for producing a resin fiber according to claim 6, wherein the plurality of pairs of the high-pressure gas outlets are provided so as to spread out in a fan shape with their respective axes directed in the ejection direction. In an apparatus for producing a resin fiber that is a very long fiber that stretches a thermoplastic resin with a high-pressure gas flow, the nozzle is used for an extruder that extrudes a molten resin from a nozzle at the tip of the barrel while melting the resin with a screw in the barrel. A nozzle head attached to the tip of the
On the face surface that is substantially vertical when attached to the manufacturing apparatus,
A discharge port for extruding the molten resin;
A pair of high-pressure gas jets that form a gas flow substantially horizontally in the vicinity of the discharge port, and are given a plurality of pairs ,
The high-pressure gas jet port is positioned in the vicinity of the discharge port and the diameter of the discharge port is set to 0.5 mm or more so that the molten resin inside the discharge port is drawn out and released into the air while being stretched. Characteristic nozzle head. The nozzle head according to claim 8 , wherein the plurality of pairs are provided on the face surface so as to follow a horizontal line when attached to the manufacturing apparatus. The nozzle head according to claim 9, wherein the plurality of pairs of the high-pressure gas outlets are provided so as to spread in a fan shape with their respective axes directed in the ejection direction.