Polylactic acid melt-blown fiber production and treatment process and device

Abstract

The invention provides a polylactic acid melt-blown fiber production treatment process and device. The polylactic acid melt-blown fiber production device comprises an extrusion device, a melt-blown module, an airflow system and a receiving device, wherein the receiving device is arranged below the discharge end of the melt-blown module; the melt-blowing module comprises a hot melting die head, a spinneret plate and a spinneret, and a material channel is arranged in the hot melting die head; the discharging end of the extrusion device is connected with the feeding end of the material channel, and the spinneret plate is installed at the discharging end of the material channel. A mounting groove is formed in the spinneret plate, and the spinneret is detachably mounted in the mounting groove; a spinning hole communicated with the material channel is formed in the spinning nozzle; according to the spinneret plate, the problems that in the prior art, when spinneret orifices directly machined in the spinneret plate are blocked or damaged, the whole spinneret plate needs to be cleaned or replaced, and the hole diameter, the hole distance and the hole shape of the spinneret orifices cannot be adjusted can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of meltblown devices, and specifically to a production and processing process and device for polylactic acid meltblown fibers. Background Art

[0002] Meltblowing is a process technology for producing ultra-fine fiber non-woven fabrics (non-woven cloth), mainly applied in fields such as filter materials, medical protective supplies, and oil-absorbing materials. The meltblowing technology endows materials with high-efficiency filtering and adsorption properties through the unique structure of the produced ultra-fine fibers, and is irreplaceable especially in the manufacture of medical protective supplies, medical hygiene preparations, and the environmental protection field.

[0003] Existing meltblown devices can extrude a melt stream through the spinneret holes provided on the spinneret plate, and then use high-speed hot air to instantaneously stretch the melt to achieve the production of an ultra-fine fiber (web) structure; for example, the invention with the publication number CN118721944A discloses a multi-layer composite non-woven material and its preparation method and preparation system (hereinafter referred to as the prior art 1), that is, the first fiber web layer and the second fiber web layer of the composite material are prepared by meltblowing or spunbonding as the outermost two surface layers of the composite material; at the same time, the short fibers with cardability are obtained through the method of carding into a web to form a carded web, and the short fibers are mixed with the filaments obtained by meltblowing the carded web to form a mixed web, and the carded web and / or the mixed web are used as the intermediate water-absorbing layer web of the composite material, and the composite non-woven material is obtained after hot rolling, pre-hydroentangling, hydroentangling, and drying.

[0004] The spinneret holes in the prior art 1 are directly processed on the spinneret plate, so that when the spinneret head is blocked or damaged, the entire spinneret plate needs to be cleaned or replaced, with high maintenance costs and long maintenance time; and the aperture, hole pitch, and hole shape of the spinneret holes in the prior art 1 are determined during manufacturing and cannot be adjusted according to product requirements. Summary of the Invention

[0005] The purpose of the present invention is to provide a production and processing process and device for polylactic acid meltblown fibers, which can solve the problems in the prior art that when the spinneret holes directly processed on the spinneret plate are blocked or damaged, the entire spinneret plate needs to be cleaned or replaced, with high maintenance costs and long maintenance time, and the aperture, hole pitch, and hole shape of the spinneret holes cannot be adjusted during actual use.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A polylactic acid meltblown fiber production device includes an extrusion device, a meltblown module, an air flow system, and a receiving device. The receiving device is arranged below the discharge end of the meltblown module;

[0008] The melt - blown module includes a hot - melt die head, a spinneret plate, and a spinneret. A material channel is provided inside the hot - melt die head; the discharge end of the extrusion device is connected to the feed end of the material channel, and the spinneret plate is installed at the discharge end of the material channel; an installation groove is provided on the spinneret plate, and the spinneret is detachably installed in the installation groove;

[0009] The spinneret is provided with spinneret holes communicating with the material channel, and the hot - melt die head is used to heat the material in the material channel.

[0010] Preferably, the air - flow system includes an air - knife system and an air - outlet system. The air - outlet system is arranged below the receiving device. The air - knife system includes a hot - air blower and an air - knife flow channel, and the air - knife flow channel is communicated with the material channel.

[0011] Preferably, the air - outlet system includes an air box and an air - distributing hood installed in the air box. The air - distributing hood is provided with air - outlet holes.

[0012] Preferably, a filter screen is installed inside the air box.

[0013] Preferably, the extrusion device includes a housing and a conveying assembly. A material cavity and a heating assembly are provided inside the housing. A feed hopper is installed at the feed inlet of the material cavity, and the discharge outlet of the material cavity is connected to the feed end of the hot - melt die head; the heating assembly is used to heat the material in the material cavity, and the conveying assembly is used to convey the material in the material cavity.

[0014] Preferably, the heating assembly includes a heating plate, a first heating coil, and a second heating coil. The heating plate is installed in the feed hopper, and the first heating coil and the second heating coil are installed inside the housing.

[0015] Preferably, the conveying assembly includes a driving motor and a screw. The screw is rotatably installed on the housing, and the driving motor is used to drive the screw to rotate.

[0016] Preferably, the feed hopper is installed on the housing. The discharge end of the feed hopper is connected with a telescopic pipe. The feed hopper is connected to the feed end of the housing through the telescopic pipe, and a telescopic device for driving the telescopic pipe to expand and contract is installed on the feed hopper.

[0017] Preferably, a heat - conducting block is provided inside the air - knife flow channel.

[0018] A production and treatment process for polylactic acid melt - blown fibers, specifically a method for producing and treating polylactic acid fibers, includes the following steps:

[0019] Step 1: Pretreat the polylactic acid fiber raw material;

[0020] Step 2: Heat and melt the polylactic acid fiber raw material through an extrusion device, and transport the melted material to the meltblown module;

[0021] Step 3: The meltblown module extrudes the melt into fibers, and the fibers are stretched and refined through an air flow system;

[0022] Step 4: Collect the fibers through a receiving device, so that the fibers form a fiber web structure on the receiving device.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] In the present invention, a plurality of installation grooves are provided on the spinneret plate, and a spinneret head can be detachably installed in each installation groove; there are a plurality of spinneret holes provided on each spinneret head, and the spinneret holes can be circular, triangular, cross-shaped, annular, C-shaped, strip-shaped or other circular or non-circular cross-sectional structures;

[0025] By replacing the spinneret heads in different installation grooves, the diameter, shape and hole pitch of the spinneret holes installed on the spinneret plate can be changed, and fibers with different cross-sectional shapes can be produced according to actual needs. A composite mixed fiber structure can also be produced by replacing one or several spinneret heads with different-shaped spinneret holes. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention, and therefore should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 Is a perspective view of the present invention.

[0028] Figure 2 Is a structural schematic diagram of the present invention.

[0029] Figure 3 Is the present invention Figure 2 The partial enlarged view of A in.

[0030] Figure 4 Is the present invention Figure 2 The partial enlarged view of B in.

[0031] Figure 5 Is the present invention Figure 2 The partial enlarged view of C in.

[0032] Figure 6 Is a schematic diagram of the connection relationship between the spinneret head and the spinneret plate in the present invention.

[0033] Figure 7 For the present invention Figure 6 is a partial enlarged view of the D part in the present invention.

[0034] In the attached drawings, the list of components represented by each reference numeral is as follows:

[0035] 1 - Extrusion device, 2 - Melt - blowing module, 3 - Air - flow system, 4 - Receiving device, 11 - Housing, 12 - Conveying component, 13 - Material cavity, 14 - Heating component, 15 - Feed hopper, 21 - Hot - melt die head, 22 - Spinneret plate, 23 - Spinneret head, 121 - Driving motor, 122 - Screw, 141 - Heating plate, 142 - First heating coil, 143 - Second heating coil, 151 - Telescopic tube, 152 - Telescopic device, 211 - Material channel, 221 - Installation groove, 222 - Baffle, 223 - Slide groove, 224 - Relief groove, 225 - Limit groove, 226 - Roller, 231 - Spinning holes, 31 - Air - knife system, 32 - Air - outlet system, 311 - Hot - air blower, 312 - Air - knife flow channel, 321 - Air box, 322 - Air - distributing hood, 323 - Air - outlet holes. Detailed implementation manners

[0036] In the following text, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments of the present invention. Therefore, the drawings and the description are considered to be exemplary in nature rather than restrictive.

[0037] In the description of the embodiments of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "length", "vertical", "horizontal", "top", "bottom", etc. is the orientation or positional relationship based on the drawings, and is only for the convenience of describing the embodiments of the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus cannot be understood as a limitation to the embodiments of the present invention.

[0038] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the embodiments of the present invention, "a plurality" means two or more unless otherwise specifically defined.

[0039] In the embodiments of the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "connected", "fixed", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection, an electrical connection, or a communication connection; it can be directly connected, or indirectly connected through an intermediate medium, and can be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific situations.

[0040] In the embodiments of the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0041] The following disclosure provides many different embodiments or examples for implementing different structures of the embodiments of the present invention. To simplify the disclosure of the embodiments of the present invention, the components and settings of specific examples are described below. Of course, they are only examples and are not intended to limit the embodiments of the present invention. In addition, the embodiments of the present invention may repeat reference numerals and / or reference letters in different examples. This repetition is for the purpose of simplification and clarity, and does not itself indicate the relationship between the various embodiments and / or settings discussed.

[0042] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Embodiment 1

[0044] Refer to Figures 1-5 , this embodiment discloses a polylactic acid meltblown fiber production device, including an extrusion device 1, a meltblown module 2, an air flow system 3, and a receiving device 4. The receiving device 4 is arranged below the discharge end of the meltblown module 2;

[0045] The meltblown module 2 includes a hot melt die head 21, a spinneret plate 22, and a spinneret 23. A material channel 211 is arranged inside the hot melt die head 21; the discharge end of the extrusion device 1 is connected to the feed end of the material channel 211, and the spinneret plate 22 is installed at the discharge end of the material channel 211; an installation groove 221 is arranged on the spinneret plate 22, and the spinneret 23 is detachably installed in the installation groove 221;

[0046] The spinneret 23 is provided with spinneret holes 231 communicating with the material channel 211, and the hot melt die head 21 is used to heat the material in the material channel 211.

[0047] In this embodiment, the polylactic acid fiber raw material is a polylactic acid PLA raw material. A conventional heating device in the prior art is connected to the hot melt die head 21, and the heating device is used to heat the hot melt module to 170-190 °C. The structure and function of the heating device will not be elaborated here one by one. The spinneret plate 22 is installed at the discharge end of the hot melt die head 21. There are several installation grooves 221, and a spinneret 23 can be detachably installed in each installation groove 221. There are several spinneret holes 231 provided on each spinneret 23. The spinneret holes 231 can be circular, triangular, cross-shaped, annular, C-shaped, strip-shaped or other circular or non-circular cross-sectional structures. The spinneret holes 231 with a circular cross-section can form cylindrical fibers, which have the advantages of simple processing, low cost and being suitable for large-scale production. The spinneret holes 231 with a triangular / trefoil cross-section can form fibers with a triangular prism or trefoil cross-section. Compared with cylindrical fibers, the specific surface area of the fibers with a triangular prism or trefoil cross-section can be increased by 30% to 50%, which can improve the filtration efficiency, enhance the interception and inertial collision effects, and are mostly used for manufacturing high-efficiency filter materials. The spinneret holes 231 with a cross-shaped / star-shaped cross-section can produce fibers with micro-grooves or protrusions on the surface, thereby increasing the roughness of the fiber surface, improving the air permeability and enhancing the fluffiness of the fiber web, and increasing the liquid adsorption capacity (capillary effect); the hollow spinneret holes 231 can produce hollow fibers that can improve the heat insulation and sound insulation performance and enhance the wicking effect when used for transporting liquids. In this embodiment, there are three installation grooves 221. The number of spinneret holes 231 on the three installation grooves 221 is 100-300, and the diameter of the spinneret holes 231 is 0.2-0.5 mm. By replacing the spinnerets 23 in different installation grooves 221, spinneret holes 231 with different diameters and shapes can be replaced, and fibers with different cross-sectional shapes can be produced according to actual needs. A composite mixed fiber structure can also be produced by replacing one or several spinnerets 23 with spinneret holes 231 of different shapes. The spinneret 23 and the spinneret plate 22 are detachably connected by locking bolts. In this embodiment, the receiving device 4 is a conventional drum-type receiver or a mesh curtain-type receiver in the prior art. In this embodiment, the receiving device 4 is a mesh curtain-type porous conveying mechanism, which can improve the uniformity of the fiber web after forming. The specific structure and function will not be elaborated here one by one.

[0048] Among them, the air flow system 3 includes an air knife system 31 and an air outlet system 32. The air outlet system 32 is arranged below the receiving device 4. The air knife system 31 includes a hot air blower 311 and an air knife flow channel 312, and the air knife flow channel 312 is communicated with the material channel 211. The air knife flow channels 312 are symmetrically arranged on the left and right sides of the discharge port of the material channel 211 and are communicated with the material channel 211. The two air knife flow channels 312 are both inclined towards the discharge port of the material channel 211, so that the two air knife flow channels 312 are arranged in a V-shaped structure. In this embodiment, the hot air blower 311 is used to input hot air flow at 160-180°C into the air knife flow channel 312. After the hot air flow enters the air knife flow channel 312, it exchanges heat with the hot melt die head 21, so that the temperature of the hot melt die head 21 can be maintained between 170-190°C. While maintaining the fluidity of the melt, it avoids high-temperature scorching of the molten material in the hot melt die head 21. Under the guidance of the air knife flow channel 312, the hot air flow can be accurately guided to the outlet of the spinneret hole 231 to effectively stretch the molten material. The air channels symmetrically distributed on both sides of the material channel 211 can also ensure that the hot air uniformly surrounds the molten material and effectively stretches and refines the extruded molten material to form polylactic acid fibers.

[0049] Further optimized, the air outlet system 32 includes an air box 321 and a wind distribution cover 322 installed in the air box 321, and air outlet holes 323 are arranged on the wind distribution cover 322. In this embodiment, there are several air outlet holes 323 arranged on the wind distribution cover 322. By setting the wind distribution cover 322, the air flow blown out through the air outlet holes 323 can be evenly distributed. The hot air blower 311 is used to draw in external air into the air box 321 and then blow it out through the air outlet holes 323. The air flow blown out through the air outlet holes 323 forms a convection with the polylactic acid fibers extruded from the spinneret hole 231, increasing the contact time between the air flow and the fibers. While further stretching the polylactic acid fibers, it can also cool the polylactic acid fibers to facilitate the shaping of the polylactic acid fibers on the receiving device 4. The air blown out from the air outlet holes 323 can also extend the flight path and time of the fibers in the air, so that the polylactic acid fibers can be fully dispersed before contacting the receiving device 4. Since the air flow direction is opposite to the gravity direction of the polylactic acid fibers, the landing point of the polylactic acid fibers can be adjusted, avoiding local accumulation of the polylactic acid fibers due to gravity and improving the uniformity of the fiber web structure thickness on the surface of the receiving device 4.

[0050] Among them, a filter screen is installed in the air box 321. The filter screen is installed at the air suction port of the hot air blower 311. By setting the filter screen, the air flow drawn into the air box 321 can be filtered to avoid the air flow carrying impurities from contaminating the polylactic acid fibers after contacting them, affecting the quality of polylactic acid fiber production.

[0051] Further optimization, the extrusion device 1 includes a housing 11 and a conveying component 12. A material cavity 13 and a heating component 14 are arranged in the housing 11. A feed hopper 15 is installed at the feed inlet of the material cavity 13, and the discharge outlet of the material cavity 13 is connected to the feed end of the hot melt die head 21. The heating component 14 is used to heat the material in the material cavity 13, and the conveying component 12 is used to convey the material in the material cavity 13. After the pretreated raw material is put into the feed hopper 15, it falls into the material cavity 13. Through the heating component 14, the material in the material cavity 13 can be heated and melted into a homogeneous melt, and then conveyed into the hot melt die head 21 through the conveying component 12.

[0052] Among them, the heating component 14 includes a heating plate 141, a first heating coil 142 and a second heating coil 143. The heating plate 141 is installed in the feed hopper 15, and the first heating coil 142 and the second heating coil 143 are installed in the housing 11. During the heating process of the polylactic acid raw material, the addition temperature needs to be controlled in segments. The temperature of the heating plate 141 installed in the feed hopper 15 is 40 - 50 °C, which is used to dry the raw material. The temperature of the first heating coil 142 is 80 - 120 °C, which prevents the polylactic acid raw material from softening prematurely and causing blockage of the material cavity 13. The temperature of the second heating coil 143 is 180 - 190 °C, reaching the melting temperature of polylactic acid to ensure complete melting and uniform plasticization. During the heating and melting process, the temperature of the second heating coil 143 should be avoided to exceed 200 °C to prevent the degradation of the polylactic acid raw material.

[0053] Further optimization, the conveying component 12 includes a driving motor 121 and a screw 122. The screw 122 is rotatably installed on the housing 11, and the driving motor 121 is used to drive the screw 122 to rotate. The driving motor 121 is used to drive the screw 122 to rotate. Through the rotating screw 122, the raw material entering the material cavity 13 can be moved towards the feed end of the hot melt die head 21. The inside of the housing 11 is divided into a feed section and a melting section. The first heating coil 142 is correspondingly arranged with the feed section, and the second heating coil 143 is correspondingly arranged with the melting section. Through the cooperation of the screw 122 and the first heating coil 142, the raw material can be conveyed. After the polylactic acid raw material is pushed by the screw 122 to the melting section, under the cooperation of the second heating coil 143 and the screw 122, the raw material completes the transformation from the solid state to the molten state. During the process of conveying the raw material, the screw 122 further mixes the raw material at the same time, eliminating the local differences in the temperature and composition of the molten material to ensure the uniformity of the melt.

[0054] For further optimization, the feed hopper 15 is installed on the housing 11. The discharge end of the feed hopper 15 is connected with a telescopic pipe 151. The feed hopper 15 is connected with the feed end of the housing 11 through the telescopic pipe 151. A telescopic device 152 for driving the telescopic pipe 151 to expand and contract is installed on the feed hopper 15. A support frame is fixedly connected to the feed hopper 15. The feed hopper 15 is connected with the housing 11 through the support frame. The discharge end of the feed hopper 15 is arranged above the feed end of the housing 11. The discharge end of the feed hopper 15 is connected with the feed end of the housing 11 through the telescopic pipe 151. A connecting block is fixedly connected to the telescopic pipe 151. The telescopic end of the telescopic device 152 installed on the feed hopper 15 is connected with the connecting block. When the telescopic end of the telescopic device 152 moves, it can drive the connecting block to move, so as to drive the telescopic pipe 151 to extend or shorten. During the repeated expansion and contraction of the telescopic pipe 151, the pipe volume can be changed to form a pressure fluctuation, which can push the material to flow faster and avoid the stagnation and accumulation of raw materials.

[0055] Wherein, a heat conducting block is arranged in the air knife flow channel 312. By arranging the heat conducting block, the moving path of the high-temperature air flow entering the air knife flow channel 312 and the contact time between the high-temperature air flow and the hot melt die head 21 can be increased, so as to improve the heating efficiency of the hot melt die head 21.

[0056] Based on the above-described polylactic acid fiber production device, this embodiment also describes a production and treatment process for polylactic acid meltblown fibers, including the following steps:

[0057] Step 1: Pretreat the polylactic acid fiber raw material;

[0058] Step 2: Heat and melt the polylactic acid fiber raw material through the extrusion device 1, and convey the melted material to the meltblowing module 2;

[0059] Step 3: The meltblowing module 2 extrudes the melt into fibers, and the fibers are drawn and refined by the air flow system 3;

[0060] Step 4: Collect the fibers through the receiving device 4, so that the fibers form a fiber web structure on the receiving device 4.

[0061] In step 1, when pretreating the polylactic acid fiber raw material, it is necessary to first clean and dry the polylactic acid raw material. A sieve plate is installed on the feed hopper 15. Through the sieve plate, the raw material after cleaning and drying can be screened to avoid the residual impurities in the raw material from entering the material cavity 13. The residual moisture in the raw material can be further dried by the heating plate 141 arranged in the material cavity 13 to ensure the quality of the polylactic acid fiber finished product.

[0062] Embodiment Two

[0063] See also Figure 3 , Figure 6 and Figure 7 This embodiment is further optimized on the basis of the first embodiment. In this embodiment, the spinneret 22 is slidably mounted on the discharge end of the hot melt die head 21. The left and right ends of the spinneret 22 are provided with fixing bolts. The spinneret 22 is detachably connected to the hot melt die head 21 through the fixing bolts. When it is necessary to clean and replace the spinneret 23 installed on the spinneret plate 22, the fixing bolts can be removed first and then the spinneret 22 can be pulled out from the left and right sides of the hot melt die head 21, and the spinneret 22 and the spinneret 23 installed on the spinneret plate 22 can be replaced and cleaned; in this embodiment, a step groove is provided at the discharge end of the hot melt die head 21, and a slider for cooperating with the step groove is provided on the spinneret 22, and the spinneret 22 is slidably installed in the step groove through the slider; by making the spinneret 22 slidably connected with the hot melt die head 21 and setting the fixing bolts on the left and right sides of the spinneret 22, it is convenient for the staff to install and replace the spinneret 22.

[0064] Further optimization is provided on the spinneret 22, and a slide groove 223 is connected to the mounting groove 221; a baffle 222 is installed in the slide groove 223; one end of the baffle 222 is rotatably connected to a roller 226; a limiting groove 225 connected to the slide groove 223 is provided on the mounting groove 221, and the roller 226 is slidably installed in the limiting groove 225; the limiting groove 225 and the slide groove 223 form a stepped structure; a yielding groove 224 is provided on the spinneret 22, and the yielding groove 224 is used to yield to the baffle 222 after rotation. When the spinneret 23 needs to be installed in the installation groove 221, the baffle plate 222 is first pushed to move in the direction of the clearance groove 224. When the roller 226 moves to contact the inner wall of the limiting groove 225, the baffle plate 222 moves to the outside of the slide groove 223. At this time, the horizontally arranged baffle plate 222 is rotated to make the baffle plate 222 stand upright so that the baffle plate 222 no longer blocks the installation groove 221, and the spinneret 23 can be installed in the installation groove 221; the space between the clearance groove 224 and the installation groove 221 A step surface is formed, and the vertically arranged baffle 222 is rotated to contact the step surface; when the number and width of the polylactic acid fiber mesh structure need to be adjusted, a suitable number of spinnerets 23 can be taken out according to the actual needs, and then the vertically arranged baffle 222 is rotated to a horizontal state and the baffle 222 is re-entered into the slide groove 223, and then the baffle 222 is pushed in the direction away from the give way groove 224, so that the baffle 222 re-covers the opening of the installation groove 221 and the polylactic acid fiber production is adjusted.

[0065] Among them, a stepped platform is provided on the baffle 222. By providing the stepped platform, after the baffle 222 is flipped to the horizontal setting, the upper surface of the stepped platform and the lower surface of the discharge port of the hot melt die head 21 are located on the same plane.

[0066] This embodiment also records a polylactic acid material, which includes 80-85 parts of polylactic acid raw material (pure PLA), 6-8 parts of citrate plasticizer, 1-3 parts of nano-talc powder, 1-2 parts of zinc stearate, 0.1-1 part of antioxidant and 1-2 parts of polyethylene glycol.

[0067] In this embodiment, the polylactic acid material includes raw materials in the following weight parts: 83 parts of polylactic acid raw material (pure PLA), 7 parts of citrate plasticizer, 2 parts of nano-talc powder, 1 part of zinc stearate, 0.5 part of antioxidant and 1 part of polyethylene glycol; among them, the citrate plasticizer can reduce the melt viscosity of polylactic acid, improve the processing fluidity, and at the same time avoid fiber breakage caused by the brittleness of pure polylactic acid; nano-talc powder is used as a nucleating agent to promote the crystallization of polylactic acid and improve the mechanical strength and heat resistance of the fiber; the antioxidant is vitamin E (tocopherol), which can inhibit the oxidative decomposition of polylactic acid during the high-temperature meltblowing process and avoid the breakage of polylactic acid molecular chains; at the same time, the vitamin E (tocopherol) can also reduce the melt viscosity, improve the uniformity of the meltblown fibers, and the vitamin E (tocopherol) has good biocompatibility, will not activate the immune system, avoid causing allergic or inflammatory reactions, and can slow down the autocatalytic hydrolysis of polylactic acid raw materials caused by moisture absorption; it is suitable for manufacturing medical hygiene preparations such as sanitary napkins, pantiliners and diapers; the zinc stearate can be used as a lubricant to improve the fluidity of the polylactic acid melt, and the polyethylene glycol can synergistically plasticize to reduce the breakage of polylactic acid fibers.

[0068] Table 1 shows the performance comparison between the polylactic acid material in this embodiment and the polylactic acid raw material (pure PLA) in the prior art:

[0069]

[0070]

[0071] Table 1

[0072] It can be seen from Table 1 that compared with the pure polylactic acid in the prior art, the polylactic acid material has improved fluidity during meltblowing, reducing the blockage of spinneret holes; the fibers are finer and more uniform, improving the filtration performance; the fiber ductility is improved, reducing brittle breakage; the nucleating agent promotes crystallization and speeds up the molding speed.

[0073] Among them, the filtration performance fibers of the polylactic acid material in this application are finer and more uniform, with improved filtration performance, and are more suitable for fields such as medical masks and air filtration materials; while significantly improving the fiber uniformity and the mechanical properties of the product, the environmental protection characteristics of the polylactic acid raw material (pure PLA) are maintained.

[0074] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0075] The above description is only for the preferred embodiments of the present invention and is not intended to limit the present invention. It should be noted that any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A polylactic acid meltblown fiber production device, characterized in that: It comprises an extrusion device (1), a melt-blowing module (2), an airflow system (3) and a receiving device (4), wherein the receiving device (4) is arranged below the discharge end of the melt-blowing module (2); The meltblowing module (2) comprises a hot melt die head (21), a spinneret (22) and a spinneret (23), wherein a material channel (211) is arranged in the hot melt die head (21); the discharge end of the extrusion device (1) is connected to the feed end of the material channel (211), and the spinneret (22) is installed at the discharge end of the material channel (211); the spinneret (22) is provided with a mounting groove (221), and the spinneret (23) is detachably installed in the mounting groove (221); The spinneret (23) is provided with a spinneret hole (231) which is in communication with the material channel (211), and the hot melt die head (21) is used to heat the material in the material channel (211).

2. A polylactic acid meltblown fiber production device according to claim 1, characterized in that: The airflow system (3) comprises an air knife system (31) and an air outlet system (32); the air outlet system (32) is arranged below the receiving device (4); the air knife system (31) comprises a hot air blower (311) and an air knife flow channel (312); the air knife flow channel (312) is connected to the material channel (211).

3. A polylactic acid meltblown fiber production device according to claim 2, characterized in that: The air outlet system (32) comprises a wind box (321) and an air distribution cover (322) installed in the wind box (321), and the air distribution cover (322) is provided with an air outlet hole (323).

4. A polylactic acid meltblown fiber production device according to claim 3, characterized in that: A filter screen is installed in the bellows (321).

5. The polylactic acid meltblown fiber production device according to claim 1, characterized in that: The extrusion device (1) comprises a shell (11) and a conveying assembly (12); a material cavity (13) and a heating assembly (14) are arranged in the shell (11); a feed port of the material cavity (13) is provided with a feed hopper (15); and a discharge port of the material cavity (13) is connected to a feed end of the hot melt die head (21); the heating assembly (14) is used to heat the material in the material cavity (13); and the conveying assembly (12) is used to convey the material in the material cavity (13).

6. A polylactic acid meltblown fiber production device according to claim 5, characterized in that: The heating assembly (14) comprises a heating plate (141), a first heating ring (142) and a second heating ring (143); the heating plate (141) is installed in a feed hopper (15); and the first heating ring (142) and the second heating ring (143) are installed in a housing (11).

7. A polylactic acid meltblown fiber production device according to claim 5, characterized in that: The conveying assembly (12) comprises a driving motor (121) and a screw (122); the screw (122) is rotatably mounted on the housing (11); and the driving motor (121) is used to drive the screw (122) to rotate.

8. The polylactic acid meltblown fiber production device according to claim 5, characterized in that: The feed hopper (15) is mounted on the housing (11); a discharge end of the feed hopper (15) is connected to a telescopic tube (151); the feed hopper (15) is connected to the feed end of the housing (11) via the telescopic tube (151); a telescopic device (152) for driving the telescopic tube (151) to telescope is mounted on the feed hopper (15).

9. A polylactic acid meltblown fiber production device according to claim 4, characterized in that: A heat conduction block is arranged in the air knife flow channel (312).

10. A polylactic acid meltblown fiber production and processing process, characterized in that: The invention relates to a polylactic acid meltblown fiber production device using any one of claims 1 to 9, specifically a method for producing and processing polylactic acid fibers, comprising the following steps: Step 1: pretreating the polylactic acid fiber raw material; Step 2: heating and melting the polylactic acid fiber raw material through the extruder (1), and conveying the molten material to the melt-blowing module (2); Step 3: The melt-blowing module (2) extrude the molten material into fibers, and the fibers are drawn and refined through the air flow system (3); Step 4: Collecting the fibers through a receiving device (4) so ​​that the fibers form a fiber web structure on the receiving device (4).

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