Meltblown spinning device without spinneret holes and meltblown spinning method

Abstract

A meltblown spinning device without spinneret holes and a meltblown spinning method are provided. The meltblown spinning device without spinneret holes includes a melt tank, a heat source, a carrier, and a nozzle. The melt tank defines an accommodation space for accommodating a melt. The heat source is used to heat the raw material of the melt. At least a part of the carrier can enter and exit the accommodation space to carry out the melt. The nozzle is used to inject an air flow onto the carrier carrying the melt, and the air flow stretches the melt to form filaments.

Description

Technical Field

[0001] The present application relates to the field of fiber spinning, and more particularly to a meltblown spinning device without spinnerets and a meltblown spinning method. Background Art

[0002] Micro-nano fibers refer to linear materials with a diameter in the micron or nano scale and a large aspect ratio. Due to their unique physical and chemical properties, micro-nano fibers are widely used in various new functional materials.

[0003] Currently, common methods for preparing micro-nano fibers include stretching method, template synthesis method, self-assembly method, meltblown spinning, wet spinning, centrifugal spinning, etc. Meltblown spinning is the most widely used method in industrial production at present, which has the advantages of high production efficiency and no need to use solvents. However, meltblown spinning extrudes the melt through spinnerets to form filaments, which makes the meltblown spinning device prone to spinneret blockage, restricting the long-term operation of the meltblown spinning device. Therefore, it is of great significance to develop a meltblown spinning device without needle blockage problems. Summary of the Invention

[0004] In view of the state of the above-mentioned prior art, the present application is made. The purpose of the present application is to provide a meltblown spinning device without spinnerets and a meltblown spinning method, which can overcome at least one of the disadvantages described in the above background art.

[0005] In order to achieve the above purpose, the present application adopts the following technical solutions.

[0006] The present application provides a meltblown spinning device without spinnerets as follows. The meltblown spinning device without spinnerets includes: a melt tank, which defines an accommodation space for accommodating the melt; a heat source for heating the raw material of the melt; a carrier, at least a part of which can enter and exit the accommodation space to carry out the melt; and a nozzle for spraying air flow onto the carrier carrying the melt, and the air flow stretches the melt to form filaments.

[0007] In an optional solution, the carrier is a flexible body and is supported as a U-shaped structure, the bottom of the U-shaped structure is located in the accommodation space, the meltblown spinning device without spinnerets includes two nozzles facing opposite directions, the two nozzles are located inside the U-shaped structure, and the carrier can reciprocate along its extending direction, so that the air flow sprayed from the two nozzles can alternately stretch the melt.

[0008] In another optional solution, the carrier is a metal wire, and the diameter of the carrier is 0.1 mm to 0.5 mm.

[0009] In another alternative, the carrier is a mesh fabric, and the mesh number of the carrier is from 10 mesh to 2000 mesh.

[0010] In another alternative, the number of the carriers is plural, and the plural carriers are arranged side by side and spaced apart from each other.

[0011] In another alternative, the nozzle includes a plurality of hollow tubes, and the plurality of hollow tubes are arranged side by side.

[0012] In another alternative, the nozzle is an air knife.

[0013] In another alternative, the distance between the output end of the nozzle and the carrier is from 2 mm to 10 mm.

[0014] In another alternative, it further includes a collector, the collector is spaced apart from the nozzle, the nozzle is aligned with the collector, and at least a part of the melt can be located between the collector and the nozzle, so that the micro-nano fibers formed by the melt can adhere to the collector.

[0015] In another alternative, it further includes a compressed air source, and the output end of the compressed air source is communicated with the nozzle for supplying the air flow to the nozzle.

[0016] This application also provides a meltblown spinning method using the above meltblown spinning device without spinneret holes. The meltblown spinning method includes: making at least a part of the carrier located in the accommodation space, the melt adhering to at least a part of the carrier; moving at least a part from the accommodation space to the flow path of the air flow; and stretching the melt by the air flow.

[0017] In an alternative, moving at least a part from the accommodation space to the flow path of the air flow includes: making at least a part reciprocate between the accommodation space and the flow path of the air flow.

[0018] By adopting the above technical solution, by using the carrier to convey the melt, the meltblown spinning device without spinneret holes can perform meltblown spinning without using a meltblown die head, avoiding the problem of melt clogging the spinneret holes, and effectively improving the stability of the meltblown spinning device. Description of the Drawings

[0019] Figure 1 A perspective view of a meltblown spinning device without spinneret holes according to a first embodiment of the present application is shown.

[0020] Figure 2 Shown is Figure 1 A schematic diagram of the meltblown spinning device without spinneret holes in, where the arrow indicates the moving direction of the moving body.

[0021] Figure 3 shows Figure 1 a scanning electron microscope image of micro-nano fibers prepared by a meltblown spinning device without spinneret holes in

[0022] Figure 4 shows a scanning electron microscope image of micro-nano fibers prepared by a meltblown spinning device without spinneret holes according to the second embodiment of the present application.

[0023] Figure 5 shows a perspective view of a meltblown spinning device without spinneret holes according to the third embodiment of the present application.

[0024] Figure 6 shows Figure 5 a scanning electron microscope image of micro-nano fibers prepared by a meltblown spinning device without spinneret holes in

[0025] Description of reference numerals

[0026] 1 Melt supply unit; 11 Melt tank; 11a Accommodation space; 12 Carrier; 13 Support; 14 Moving body; 14a Arm; 1a Melt

[0027] 2 Gas supply unit; 21 Compressed gas source; 22 Pressure reducing valve; 23 Nozzle

[0028] 3 Collection unit; 31 Collector Detailed implementation manners

[0029] The exemplary embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood that these specific descriptions are only used to teach those skilled in the art how to implement the present application, and are not used to exhaust all feasible ways of the present application, nor to limit the scope of the present application.

[0030] (First embodiment)

[0031] Figure 1 and Figure 2 shows a meltblown spinning device without spinneret holes according to the first embodiment of the present application, and the meltblown spinning device may include a melt supply unit 1, a gas supply unit 2, and a collection unit 3.

[0032] The melt supply unit 1 may include a melt tank 11, a heat source (not shown in the figure), a carrier 12, a support 13, and a moving body 14. Specifically, the melt tank 11 may be made of stainless steel, which may define a receiving space 11a for receiving the melt 1a. The heat source may be an electric heating element, which may be installed on the melt tank 11. For example, the heat source may be a tubular electric heater element. The carrier 12 may be a flexible body, such as a stainless steel wire. A plurality (illustrated as three) of carriers 12 may be arranged side by side in the axial direction of the support 13 and spaced apart from each other. The support 13 may be a roller, and a plurality (illustrated as four) of supports 13 may be arranged parallel to each other. Among them, two of the four supports 13 may be located in the receiving space 11a, and the other two of the four supports 13 may be located above the melt tank 11. The moving body 14 may include two support arms 14a fixed to each other, and the two support arms 14a may be arranged spaced apart. One end of the carrier 12 may be fixed to one support arm 14a, and the other end of the carrier 12 may be fixed to the other support arm 14a. The carrier 12 may abut against the four supports 13, so that the carrier 12 can be supported as a U-shaped structure under the guidance of the support 13. The bottom of the U-shaped structure may be located in the receiving space 11a.

[0033] Furthermore, the carrier 12 may have a specific diameter. For example, the diameter of the carrier 12 may be from 0.1 mm to 0.5 mm. In this way, the carrier 12 will neither carry too much melt 1a due to too large a diameter, causing the melt 1a to form droplets, nor carry too little melt 1a due to too small a diameter, thus affecting the spinning efficiency. Preferably, the diameter of the carrier 12 may be 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, or 0.5 mm. In this embodiment, the diameter of the carrier 12 may be 0.4 mm.

[0034] The gas supply unit 2 may include a compressed gas source 21, a pressure reducing valve 22, and a nozzle 23. Specifically, the compressed gas source 21 may be an air compressor, and the output end of the air compressor may be connected to the nozzle 23 through the pressure reducing valve 22. The nozzle 23 may include a hollow tube, and a plurality of hollow tubes may be arranged side by side in the axial direction of the support 13. The inner diameter of each hollow tube may be from 4 mm to 10 mm. In this embodiment, the inner diameter of the hollow tube may be 4 mm, and the outer diameter of the hollow tube may be 6 mm. The nozzle 23 may be provided above the melt tank 11. The output end of the nozzle 23 may face the carrier 12 and be spaced apart from the carrier 12, and the air flow ejected from the nozzle 23 may vertically pass through the carrier 12. Two nozzles 23 may be provided in the U-shaped structure, and the output ends of the two nozzles 23 may be arranged opposite to each other.

[0035] Further, the nozzle 23 and the carrier 12 can be spaced apart by a specific distance. For example, the distance between the output end of the nozzle 23 and the carrier 12 can be from 2 mm to 10 mm. In this way, the nozzle 23 will neither be contaminated by the melt 1a due to too small a spacing distance nor cause excessive air flow dissipation due to too large a spacing distance. Preferably, the distance between the output end of the nozzle 23 and the carrier 12 can be 2 mm, 4 mm, 6 mm, 8 mm or 10 mm. In this embodiment, the distance between the output end of the nozzle 23 and the carrier 12 can be 4 mm.

[0036] The collection unit 3 can include a collector 31, and the collector 31 can be a hollow cage. Specifically, the collector 31 can be spaced apart from the nozzle 23, and the output end of the nozzle 23 can be aligned with the collector 31. A part of the carrier 12 can be located between the collector 31 and the nozzle 23.

[0037] The following introduces the meltblown spinning method using this nozzleless meltblown spinning device. This meltblown spinning method can generally include:

[0038] Place at least a part of the carrier 12 in the accommodation space 11a, and the melt 1a adheres to at least a part of the carrier 12;

[0039] Move at least a part of the carrier 12 from the accommodation space 11a to the flow path of the air flow; and

[0040] Stretch the melt 1a by the air flow.

[0041] It can be in the Figure 2 shown state as the initial state of the nozzleless meltblown spinning device. Specifically, the user can place the raw material of the melt 1a in the accommodation space 11a. The raw material can be polypropylene, and the mass of the raw material can be 20 g. The heat source can heat the raw material and transform it into the melt 1a, and the heating temperature can be 220 °C. After the raw material is transformed into the melt 1a, the melt 1a can adhere to the bottom of the U-shaped structure. The moving body 14 can move to one side ( Figure 2 the right side in Figure 2 ), so that the melt 1a can be transported by the carrier 12 to the flow path of the air flow of a nozzle 23 ( Figure 2 the nozzle on the right in ). The air flow can stretch the melt 1a attached to the carrier 12 into a jet. After the jet solidifies, micro-nano fibers can be formed, and the micro-nano fibers can adhere to the collector 31 along with the air flow.

[0042] After that, the moving body 14 can move to the other side ( Figure 2 the left side in Figure 2The flow path of the air flow of the nozzle on the left side in the middle). The moving body 14 can reciprocate between one side and the other side, so that the carrier 12 can reciprocate along its extending direction, and the melt 1a can be alternately drawn by the air flows ejected from the two nozzles 23.

[0043] Compared with the traditional meltblown spinning device, by using the carrier 12 to convey the melt 1a, this nozzleless meltblown spinning device can perform meltblown spinning without using a meltblown die head, avoiding the problem of the melt 1a clogging the spinneret holes, and effectively improving the stability of the meltblown spinning device.

[0044] Furthermore, the carrier 12 can convey the melt 1a at a specific speed. For example, the moving speed of the carrier 12 can be from 0.5 cm / s to 20 cm / s. In this way, the melt 1a will neither solidify due to the too slow moving speed of the carrier 12 nor form large droplets due to the too fast moving speed of the carrier 12, thus affecting the quality of the micro-nano fibers. Preferably, the supply speed of the carrier 12 can be 0.5 cm / s, 1 cm / s, 2 cm / s, 5 cm / s, 10 cm / s or 20 cm / s. In this embodiment, the supply speed of the carrier 12 can be 5 cm / s.

[0045] By adjusting the pressure reducing valve 22, the air flow can be ejected from the nozzle 23 at a specific pressure. For example, the gauge pressure of the air flow can be from 0.01 MPa to 1 MPa. When the gauge pressure of the air flow is within the above range, the drawn melt 1a is continuous and uniform. In this way, the melt 1a will neither fail to be sufficiently drawn due to the too low gauge pressure of the air flow nor break due to the too high gauge pressure of the air flow. Preferably, the gauge pressure of the air flow can be 0.01 MPa, 0.05 MPa, 0.1 MPa, 0.2 MPa, 0.5 MPa or 1 MPa. In this embodiment, the gauge pressure of the air flow can be 0.08 MPa.

[0046] Refer to Figure 3 , which shows the scanning electron microscope (SEM) image of the micro-nano fibers. It can be seen from Figure 3 that the micro-nano fibers are continuous and smooth.

[0047] (Second Embodiment)

[0048] The nozzleless meltblown spinning device according to the second embodiment of the present application is a variant of the first embodiment, and for the features that are the same as or similar to those of the first embodiment, the detailed introduction is omitted.

[0049] In this embodiment, still refer to Figure 1 and Figure 2, the melt tank 11 can be made of aluminum alloy. The nozzle 23 can be an air knife, and the width of the nozzle 23 can be from 1 cm to 10 cm. For example, the width of the nozzle 23 can be 3 cm, and the distance between the output end of the nozzle 23 and the carrier 12 can be 6 mm. The compressed air source 21 can be a high-pressure gas cylinder. The moving speed of the carrier 12 can be 4 cm / s. The raw material of the melt 1a can be asphalt, and the mass of the raw material can be 30 g. The heating temperature of the heat source can be 310 °C.

[0050] Referring to Figure 4 , which shows the scanning electron microscope image of the micro-nano fibers produced in this embodiment. From Figure 4 it can be seen that the micro-nano fibers are continuous and smooth.

[0051] (Third Embodiment)

[0052] The nozzleless meltblown spinning device according to the third embodiment of the present application is a variant of the first embodiment. For the features that are the same or similar to those of the first embodiment, the same reference numerals are used in this embodiment, and the detailed description of these features is omitted.

[0053] Referring to Figure 5 , in this embodiment, the carrier 12 can be a strip-shaped mesh cloth, and the width of the carrier 12 can be 2 cm. The melt 1a can cover the mesh holes on the carrier 12, and the air flow ejected from the nozzle 23 can penetrate the mesh holes and stretch the melt 1a covering the mesh holes. The nozzle 23 can be an air knife, and the width of the nozzle 23 can be from 1 cm to 10 cm. For example, the width of the nozzle 23 can be 3 cm, and the distance between the output end of the nozzle 23 and the carrier 12 can be 2 mm. The moving speed of the carrier 12 can be 3 cm / s. The raw material of the melt 1a can be polycarbosilane, and the mass of the raw material can be 25 g. The heating temperature of the heat source can be 230 °C. The gauge pressure of the air flow can be 0.1 MPa.

[0054] Furthermore, the carrier 12 can have a specific mesh number. For example, the mesh number of the carrier 12 can be from 10 mesh to 2000 mesh. In this way, the nozzleless meltblown spinning device will not have a low spinning efficiency due to too small a mesh number of the carrier 12, and the jets formed by the melt 1a will not interfere with each other due to too large a mesh number of the carrier 12. Preferably, the mesh number of the carrier 12 can be 20 mesh, 50 mesh, 80 mesh, 100 mesh, 200 mesh, 500 mesh, 800 mesh, 1000 mesh, 1500 mesh or 2000 mesh. In this embodiment, the mesh number of the carrier 12 can be 50 mesh.

[0055] Referring to Figure 6 , which shows the scanning electron microscope image of the micro-nano fibers produced in this embodiment. From Figure 6 it can be seen that the micro-nano fibers are continuous and smooth.

[0056] It should be understood that the above embodiments are merely exemplary and are not used to limit the present application. Those skilled in the art can make various modifications and changes to the above embodiments under the teaching of the present application without departing from the scope of the present application.

[0057] It should be understood that the heat source can be in direct contact with the raw material of the melt 1a or the melt 1a, or the raw material of the melt 1a or the melt 1a can be heated through a heat medium. For example, the heat medium can be the wall of the melt tank 11 and heat-conducting oil.

[0058] It should be understood that the raw material of the melt 1a is not limited to polypropylene, asphalt, and polycarbosilane, and it can include any possible materials well-known to those skilled in the art. For example, the raw material of the melt 1a can include polymer materials and inorganic non-metallic materials. Preferably, the polymer materials can include one or more of polyethylene, polypropylene, polystyrene, polyethylene terephthalate, polyvinyl alcohol, polyethylene glycol, polylactic acid, poly(lactic acid-glycolic acid) copolymer, polycaprolactone, polyurethane, polyvinylidene fluoride, polymethyl methacrylate, nylon, ethylene / vinyl alcohol copolymer, polyimide, polyamide, polyethersulfone, lignin, polyvinyl butyral, polycarbonate, asphalt, polycarbosilane, and polysilazane. The inorganic non-metallic materials include one or more of silicon dioxide, alumina, boron oxide, and aluminum silicate.

[0059] It should be understood that the carrier 12 is not limited to a flexible body and can be, for example, a rigid body. In the first embodiment and the second embodiment, the carrier 12 is not limited to being made of stainless steel. For example, the carrier 12 can also be made of copper or nickel-chromium alloy. The number of carriers 12 is not limited to three and can be single or multiple. The carrier 12 is not limited to continuously extending and can also be discontinuous.

[0060] It should be understood that the melt tank 11 is not limited to being made of stainless steel or aluminum alloy. For example, the melt tank 11 can be made of enamel.

[0061] It should be understood that the support 13 is not limited to a roller. For example, the support 13 can be a shaft body fixed to the melt tank 11.

[0062] It should be understood that the nozzle 23 is not limited to a hollow tube or an air knife. For example, the nozzle 23 can be a duckbill nozzle.

[0063] It should be understood that the collector 31 is not limited to a hollow cage. For example, the collector 31 can be a mesh cloth or a drum.

Claims

1. A meltblown spinning device without spinneret holes, characterized in that, comprising: a melt tank (11) that defines a receiving space (11a) for receiving a melt (1a); a heat source for heating the raw material of the melt (1a); a carrier (12), at least a part of which can enter and exit the receiving space (11a) to carry out the melt (1a); a nozzle (23) for injecting an air flow onto the carrier (12) carrying the melt (1a), the air flow stretching the melt (1a) to form the melt (1a) into filaments, a moving body (14) comprising two support arms (14a) fixed to each other, the two support arms (14a) being arranged at intervals, one end of the carrier (12) being fixed to one of the support arms (14a), and the other end of the carrier (12) being fixed to the other support arm (14a); and a support body (13), the carrier (12) abuts against the support body (13), and a plurality of the carriers (12) are arranged side by side and spaced apart from each other in the axial direction of the support body (13); the carrier (12) is a flexible body and is supported by the support body (13) into a U-shaped structure, the bottom of the U-shaped structure is located in the receiving space (11a), the meltblown spinning device without spinneret holes includes two nozzles (23) facing in opposite directions, the two nozzles (23) are located within the U-shaped structure, and the carrier (12) can reciprocate along its extending direction so that the air flow ejected from the two nozzles (23) can alternately stretch the melt (1a).

2. The meltblown spinning device without spinneret holes according to claim 1, characterized in that, the carrier (12) is a metal wire, and the diameter of the carrier (12) is 0.1 mm to 0.5 mm.

3. The meltblown spinning device without spinneret holes according to claim 1, characterized in that, the carrier (12) is a mesh cloth, and the mesh number of the carrier (12) is 10 mesh to 2000 mesh.

4. The meltblown spinning device without spinneret holes according to any one of claims 1 to 3, characterized in that, the nozzle (23) includes a plurality of hollow tubes arranged side by side.

5. The meltblown spinning device without spinneret holes according to any one of claims 1 to 3, characterized in that, the nozzle (23) is an air knife.

6. The meltblown spinning device without spinneret holes according to any one of claims 1 to 3, characterized in that, the distance between the output end of the nozzle (23) and the carrier (12) is 2 mm to 10 mm.

7. A meltblown spinning method, characterized in that, using the meltblown spinning device without spinneret holes according to any one of claims 1 to 6, the meltblown spinning method includes: placing at least a part of the carrier (12) in the receiving space (11a), and the melt (1a) adheres to the at least a part; moving the at least a part from the receiving space (11a) to the flow path of the air flow; and stretching the melt (1a) by the air flow.

8. The meltblown spinning method according to claim 7, characterized in that, causing at least a part thereof to move from the accommodation space (11a) to the flow path of the air stream includes: causing at least a part thereof to reciprocate between the accommodation space (11a) and the flow path of the air stream.

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