Melt-blowing die head assembly for producing hollow fibers
By designing a meltblown die head assembly with a simple structure and low manufacturing cost, and adopting a "C"-shaped spinneret hole and air guide slit structure, the problem that the existing meltblown head cannot prepare hollow fibers is solved, and efficient and economical hollow fiber production is achieved.
Patent Information
- Application Number
- CN202421904745.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-07
- Publication Date
- 2025-05-27
- Estimated Expiration
- 2034-08-07
AI Technical Summary
The existing meltblown heads are mainly used to produce solid fibers, and hollow fibers cannot be effectively prepared, and the transformation plan has problems such as complex structure, low production efficiency and high manufacturing cost.
A meltblown die head assembly with simple structure, low manufacturing cost and high production efficiency is designed. It adopts a "C"-shaped spinneret hole and air guide slit structure to continuously extrude the polymer through the "C"-shaped spinneret hole, and combines the extrusion and traction of high-speed air flow to form hollow fibers.
It realizes efficient, economical and simple process flow for producing hollow fibers, reduces the complexity of equipment and manufacturing costs, and improves production efficiency and product quality.
Smart Images
Figure CN222908174U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to a melt - blown non - woven fabric machine, and particularly to a melt - blown die head assembly for producing hollow fibers. Background Technique
[0002] The melt - blown process is an important method for manufacturing non - woven fabrics. Its principle is to heat and melt a thermoplastic polymer and extrude it through a melt - blown die head. At the same time, high - temperature and high - pressure air is used to stretch it into ultrafine fibers, which are cooled and solidified to form non - woven fabrics. In this process, the melt - blown die head plays a key role. The melt - blown die head mainly includes a spinneret plate, a heating system, an air nozzle, and a polymer flow channel. The fine holes on the spinneret plate determine the diameter and uniformity of the fibers; the heating system ensures that the polymer is melted and suitable for extrusion; the air nozzle provides high - temperature and high - pressure air to stretch and preliminarily cool the fibers; the polymer flow channel ensures the uniform distribution and stable passage of the polymer melt through the spinneret plate. The precise design and coordinated operation of these components directly affect the final quality and performance of the non - woven fabric.
[0003] Hollow fibers have a cavity structure inside, and this special structure endows them with many advantages. First of all, due to the internal cavity, hollow fibers have a low density, significantly reducing the weight while maintaining strength. Secondly, the air cavity inside the hollow fibers has good heat insulation performance and is suitable for thermal insulation materials and clothing fillers. Moreover, the cavity structure of hollow fibers can effectively absorb sound, improving the sound absorption and noise reduction effect of the material, and is suitable for sound insulation materials in buildings and automobiles. The hollow structure also increases the surface area and porosity of the fibers, improving the air permeability of the material, and is suitable for medical protection and high - end filter materials. Finally, the unique structure of hollow fibers gives them better resilience and softness, improving the comfort and durability of the material. These advantages make hollow fibers show great potential and market demand in many application fields.
[0004] However, although the melt - blown process is very important in non - woven fabric production, the existing melt - blown die heads are mainly designed for producing solid fibers, and their spinneret hole structures cannot prepare hollow fibers. To solve this problem, many technical solutions based on modifying traditional melt - blown die heads have been proposed in the industry, but these solutions generally have many deficiencies such as complex structures, low production efficiency, and high manufacturing costs. Summary of the Utility Model
[0005] Aiming at the technical problems existing in the prior art, the purpose of the present utility model is to provide a melt - blown die head assembly for producing hollow fibers with a simple structure, low manufacturing cost, and high production efficiency.
[0006] To achieve the above - mentioned purpose, the present utility model adopts the following technical solutions:
[0007] A meltblown die head assembly for producing hollow fibers, comprising a feed plate, a spinneret plate, an air plate and end caps, the outer shape of which is rectangular. The spinneret plate is located between the feed plate and the air plate and is connected to each other by screws. The end caps are fixed to the front and rear end faces of the feed plate and the spinneret plate by screws. A rectangular groove that completely penetrates along its length direction is opened at the bottom end of the spinneret plate. A protruding inverted conical spinneret head is provided in the middle of the entire groove. The bottom end of the inverted conical spinneret head is milled into a plane, and two rows of "C"-shaped spinneret holes that are parallel to each other but densely arranged in a staggered manner are drilled on the plane. The other end of the spinneret hole communicates with an inwardly concave storage cavity opened in the spinneret plate. A row of air intake through holes are respectively drilled on both sides of the storage cavity. The feed plate is located above the spinneret plate. A feed port is opened in the middle of the feed plate. The feed port communicates with the storage cavity in the spinneret plate. An air intake channel is also opened in the feed plate. The air intake channel communicates with the top end of the air intake through hole in the spinneret plate. There are two air plates, which are installed in the rectangular groove and are located on both sides of the inverted conical spinneret head. A convergent air guiding slit is formed between the two air plates and the two side walls of the inverted conical spinneret head. The air guiding slit extends upward to form an air guiding cavity, and the air guiding cavity communicates with the bottom end of the air intake through hole in the spinneret plate. The air guiding slit extends downward to the bottom end face of the "C"-shaped spinneret hole or below. The width of the air outlet formed at the bottom end of the air guiding slit is greater than or equal to twice the outer diameter of the "C"-shaped spinneret hole.
[0008] Preferably, the inner diameter of the "C"-shaped spinneret hole is 0.2 - 0.8 mm, and the outer diameter is 0.4 - 1.0 mm; the row spacing between the two rows of parallel "C"-shaped spinneret holes is 0.7 - 1.3 mm, and the center distance between two adjacent "C"-shaped spinneret holes in the same row is 0.75 - 1.35 mm. By adopting the above preferred design parameters, it is possible to ensure the processing accuracy when manufacturing the "C"-shaped spinneret holes and greatly reduce the manufacturing cost.
[0009] Preferably, a heating pipeline for introducing high-temperature heat-conducting oil or high-temperature water vapor is also opened in the spinneret plate. The above setting can maintain the entire die head assembly at a suitable temperature, ensure that the polymer melt flowing through the meltblown die head assembly is always in the best molten state, and provide a guarantee for the stable production of high-quality hollow fibers.
[0010] Preferably, a heating element installation hole for burying an electric heating rod, an infrared heating tube or an electromagnetic induction coil is also opened in the spinneret plate. The above setting can maintain the entire die head assembly at a suitable temperature, ensure that the polymer melt flowing through the meltblown die head assembly is always in the best molten state, and provide a guarantee for the stable production of high-quality hollow fibers.
[0011] Preferably, a row of adjusting screws is provided on each of the two side walls of the spinneret plate; the end of the adjusting screw abuts against the side wall surface of the air plate, and the left and right positions of the air plate are finely adjusted by rotating the screwing depth of the adjusting screw, thereby finely adjusting the gap size of the air guiding slit, so as to control the flow rate of the high-temperature air flow in the air guiding slit.
[0012] Preferably, heat insulation and heat preservation layers are also provided on the two side wall surfaces of the feed plate and the spinneret plate. The setting of the heat insulation and heat preservation layer can not only effectively reduce the heat dissipation of the meltblown die head assembly and improve the energy utilization rate, but also avoid the potential safety hazard of causing high-temperature injuries to equipment operators during the production process.
[0013] Preferably, a positioning groove is machined on the contact surface of the spinneret plate with the feed plate; a positioning boss is machined on the contact surface of the feed plate with the spinneret plate; the positioning boss is aligned with the positioning groove, and the two form a clearance fit relationship. The setting of the positioning boss and the positioning groove can ensure the assembly accuracy between the feed plate and the spinneret plate, thereby avoiding the overflow of the high-temperature polymer melt or the leakage of high-temperature and high-pressure gas at the contact surface position of the feed plate and the spinneret plate.
[0014] Preferably, the positioning groove is located between the material storage cavity and the air inlet through hole.
[0015] Preferably, the material storage cavity is strip-shaped and extends along the length direction of the spinneret plate; the upper end of the feed port is located in the middle of the upper plane of the feed plate, and the lower end of the feed port extends along the length direction of the feed plate.
[0016] Preferably, the air guiding chamber is strip-shaped and extends along the length direction of the air plate; the air inlet channel is right-angled, one end of the air inlet channel is located on the side surface of the feed plate, and the other end is located at the bottom of the feed plate; the air inlet through hole penetrates the spinneret plate along the vertical direction.
[0017] The process and principle of producing hollow fibers by the meltblown die head assembly proposed by the present utility model are as follows:
[0018] First, the polymer melt plasticized and melted by the extruder enters the material storage cavity in the spinneret plate through the feed port in the feed plate. Then, these molten polymers are continuously extruded from the "C"-shaped spinneret holes to form a tubular fiber with an open structure. At the same time, high-temperature and high-pressure air passes through the air inlet channel in the feed plate, and then through the air inlet through hole in the spinneret plate, and enters the air guiding chamber. Subsequently, these air form a stable high-speed air flow in the air guiding slit and are ejected from the air outlet of the air guiding slit to squeeze and pull the tubular fiber with an open structure extruded from the "C"-shaped spinneret hole.
[0019] In this process, under the extrusion of the high-speed air flow, the melts on both sides of the opening position of the fiber will come into contact with each other and bond and fuse together to form a closed tubular fiber. At the same time, the air enclosed inside the tube will build up a certain pressure to resist the contact and fusion of the inner wall of the fiber under the extrusion of the high-speed air flow. Finally, under the traction of the high-speed air flow, after the fiber cools and solidifies, ultrafine hollow fibers are formed.
[0020] The utility model has the following beneficial effects compared with the prior art:
[0021] (1) Simple structure. The spinneret plate in the utility model adopts a "C"-shaped spinneret hole. Compared with the spinneret holes with an internal and external multi-layer structure designed in the traditional hollow fiber meltblown die head, the structure of the spinneret plate is simpler.
[0022] (2) Low processing and manufacturing cost. Traditional hollow fiber production equipment requires precision machining of multiple layers of spinneret holes and complex internal channels, while the "C"-shaped spinneret hole proposed in the utility model can be completed by conventional processing equipment without the need for special processing techniques or high-precision equipment. This not only reduces the manufacturing cost of the spinneret plate but also reduces the manufacturing time and labor input of the meltblown die head assembly.
[0023] (3) High production efficiency. The "C"-shaped spinneret hole structure proposed in the utility model reduces the resistance of the molten polymer passing through the spinneret hole, enabling the molten polymer to be extruded more smoothly and reducing the possibility of blockage. Therefore, the maintenance and cleaning of the spinneret plate are also more convenient, thereby reducing the equipment downtime and improving the overall production efficiency. Description of the Drawings
[0024] Figure 1 is the overall structure diagram of the meltblown die head assembly of the utility model.
[0025] Figure 2 is the exploded structure diagram of the meltblown die head assembly of the utility model.
[0026] Figure 3 is the cross-sectional view of the meltblown die head assembly of the utility model.
[0027] Figure 4 is Figure 3 the partial enlarged view at A in
[0028] Figure 5 is the overall structure diagram of the spinneret plate.
[0029] Figure 6 is the bottom view of the spinneret plate.
[0030] Figure 7 is the overall structure diagram of the feed plate.
[0031] Figure 8 is Figure 6 The partial enlarged view at position B in
[0032] Figure 9 is a schematic diagram of the principle for preparing hollow fibers.
[0033] The symbols in the above figures are explained as follows:
[0034] 1 - Feed plate; 11 - Feed inlet; 12 - Air inlet channel; 13 - Positioning boss;
[0035] 2 - Spinneret plate; 21 - Rectangular groove; 22 - Inverted conical spinneret head; 23 - "C"-shaped spinneret holes; 24 - Material storage cavity; 25 - Air inlet through holes; 26 - Mounting holes; 27 - Positioning groove;
[0036] 3 - Air plate; 31 - Air guiding slit; 32 - Air guiding chamber;
[0037] 4 - End cap; 5 - Screw; 6 - Adjusting screw; 7 - Heat insulation layer; 8 - Tubular fiber with an opening structure; 9 - Closed tubular fiber; 10 - Ultra-fine hollow fiber. Specific embodiments
[0038] The present utility model will be further described in detail below in conjunction with embodiments and the accompanying drawings, but the embodiments of the present utility model are not limited thereto.
[0039] Embodiment
[0040] As Figures 1-8 shown, a meltblown die head assembly for producing hollow fibers includes a feed plate 1, a spinneret plate 2, an air plate 3, and an end cap 4 with a cuboid shape. The spinneret plate 2 is located between the feed plate 1 and the air plate 3 and is connected to each other by screws 5; the end cap 4 is fixed to the front and rear end faces of the feed plate 1 and the spinneret plate 2 by screws 5.
[0041] A rectangular groove 21 that completely penetrates along its length direction is provided at the bottom end of the spinneret plate 2, and a protruding inverted conical spinneret head 22 is provided in the middle of the entire rectangular groove 21. The bottom end of the inverted conical spinneret head 22 is milled into a flat surface, and two rows of "C"-shaped spinneret holes 23 that are parallel to each other but densely arranged in a staggered manner are drilled on the flat surface. The other end of the "C"-shaped spinneret holes 23 communicates with the concave material storage cavity 24 provided in the spinneret plate 2, and a row of air inlet through holes 25 are respectively drilled on both sides of the material storage cavity 24. In addition, 2 mounting holes 26 for embedding electric heating rods are also provided in the spinneret plate 2.
[0042] The feed plate 1 is located above the spinneret plate 2. A feed inlet 11 is provided in the middle of the feed plate 1, and the feed inlet 11 communicates with the material storage cavity 24 in the spinneret plate 2. An air inlet channel 12 is also provided in the feed plate 1, and the air inlet channel 12 communicates with the top end of the air inlet through holes 25 in the spinneret plate 2.
[0043] The air plates 3 are two pieces, which are respectively installed in the rectangular grooves 21 on both sides of the inverted conical spinneret 22. A converging air guiding slit 31 is formed between the two air plates 3 and the side walls of the inverted conical spinneret 22. The air guiding slit 31 extends upward to form an air guiding chamber 32. The air guiding chamber 32 communicates with the bottom end of the air inlet through hole 25 in the spinneret plate 2. The air guiding slit 31 extends downward to a position about 2 - 5 mm below the bottom end face of the "C"-shaped spinneret hole 23. The width of the air outlet of the air guiding slit 31 is greater than twice the outer diameter of the "C"-shaped spinneret hole 23, so that the air plate will not block the extrusion of the material from the "C"-shaped spinneret hole downward.
[0044] In this embodiment, the inner diameter of the "C"-shaped spinneret hole 23 is 0.5 mm, and the outer diameter is 0.7 mm; the row spacing between two rows of parallel "C"-shaped spinneret holes 23 is 1 mm, and the center distance between two adjacent "C"-shaped spinneret holes 23 in the same row is 1.05 mm (see Figure 8 ).
[0045] A number of adjusting screws 6 are respectively provided on the side walls of the spinneret plate 2, and the ends thereof are abutted against the side wall surfaces of the air plates 3. By rotating the adjusting screws 6, the gap size of the air guiding slit 31 can be finely adjusted, and further the flow rate of the high-temperature and high-pressure air flow in the air guiding slit 31 can be controlled.
[0046] In addition, heat insulation and heat preservation layers 7 are also provided on the side wall surfaces of the feeding plate 1 and the spinneret plate 2. The setting of the heat insulation and heat preservation layers 7 can not only effectively reduce the heat dissipation of the melt blowing die head assembly and improve the energy utilization rate, but also avoid the safety hazard of high-temperature scalding to the equipment operators during the production process.
[0047] As Figure 5 shown, a positioning groove 27 is machined on the contact surface of the spinneret plate 2 with the feeding plate 1. The positioning groove 27 is between the material storage cavity 24 and the air inlet through hole 25.
[0048] As Figure 7 shown, a positioning boss 13 is machined on the contact surface of the feeding plate 1 with the spinneret plate 3. The positioning boss 13 is opposite to the positioning groove 27, and the two form a clearance fit relationship. The setting of the positioning boss 13 and the positioning groove 27 can ensure the assembly accuracy between the feeding plate 1 and the spinneret plate 2, so as to avoid the overflow of the high-temperature polymer melt or the leakage of the high-temperature and high-pressure gas at the contact surface position of the feeding plate 1 and the spinneret plate 2.
[0049] The working principle of the present utility model is briefly described as follows:
[0050] First, the polymer melt plasticized and melted by the extruder enters the storage cavity 24 in the spinneret plate 2 through the feed port 11 in the feed plate 1. Then, these molten polymers are continuously extruded from the "C"-shaped spinneret holes 23 to form a tubular fiber 8 with an open structure. At the same time, high-temperature and high-pressure air passes through the air inlet channel 12 in the feed plate 1, and then through the air inlet through-hole 25 in the spinneret plate 2, and enters the air guiding chamber 32. Subsequently, this air forms a stable high-speed air flow in the air guiding slit 31 and is ejected from the air outlet of the air guiding slit 31 to squeeze and draw the tubular fiber 8 with an open structure extruded from the "C"-shaped spinneret holes 23.
[0051] In this process, under the squeezing action of the high-speed air flow, the melts on both sides of the opening position of the tubular fiber 8 with an open structure come into contact with each other and bond and fuse together to form a closed tubular fiber 9. At the same time, the air enclosed inside the tube will build up a certain pressure to resist the contact fusion of the inner wall of the fiber under the squeezing action of the high-speed air flow. Finally, under the traction action of the high-speed air flow, after the fiber cools and solidifies, an ultra-fine hollow fiber 10 is formed, as Figure 9 shown.
[0052] The above embodiments are the preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present utility model shall be equivalent replacement methods and are all included in the protection scope of the present utility model.
Claims
1. A meltblowing die head assembly for producing hollow fibers, comprising a feed plate, a spinneret, a wind plate and an end cover in a rectangular shape, wherein the spinneret is located between the feed plate and the wind plate and connected to each other by screws, and the end cover is fixed to the front and rear end surfaces of the feed plate and the spinneret by screws; characterized in that: The bottom end of the spinneret is provided with a rectangular groove which runs completely through the length direction thereof, and a protruding inverted cone spinneret is provided along the middle of the entire groove; the bottom end of the inverted cone spinneret is milled into a plane, and two rows of "C"-shaped spinneret holes which are parallel to each other but densely arranged in a staggered manner are drilled on the plane, and the other end of the spinneret holes is connected to the concave storage cavity provided in the spinneret; a row of air intake holes are drilled on both sides of the storage cavity; the feed plate is located at the upper end of the spinneret, and a feed port is provided in the middle of the feed plate, and the feed port is connected to the storage cavity in the spinneret, and the feed plate An air inlet passage is also provided, which is connected to the top of the air inlet hole in the spinneret; there are two air plates, which are installed in the rectangular groove and located on both sides of the inverted cone spinneret; a convergent air guide slit is formed between the two air plates and the two side walls of the inverted cone spinneret; the air guide slit extends upward to form an air guide chamber, which is connected to the bottom end of the air inlet hole in the spinneret, and the air guide slit extends downward to the bottom end face of the "C"-shaped spinneret orifice or below, and the width of the air outlet formed at the bottom end of the air guide slit is greater than or equal to twice the outer diameter of the "C"-shaped spinneret orifice.
2. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The inner diameter of the "C"-shaped spinneret hole is 0.2-0.8 mm, and the outer diameter is 0.4-1.0 mm; the row spacing between two parallel rows of "C"-shaped spinneret holes is 0.7-1.3 mm, and the center distance between two adjacent "C"-shaped spinneret holes in the same row is 0.75-1.35 mm.
3. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The spinneret is also provided with a heating pipeline for introducing high-temperature heat-conducting oil or high-temperature water vapor.
4. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The spinneret is also provided with a heating element installation hole for burying an electric heating rod, an infrared heating tube or an electromagnetic induction coil.
5. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: A row of adjusting screws is provided on each side wall of the spinneret; the ends of the adjusting screws abut against the side wall surface of the wind plate, and the left and right positions of the wind plate are fine-tuned by rotating the adjusting screws to a certain depth, thereby fine-tuning the gap size of the air guide slit to control the flow rate of the high-temperature airflow in the air guide slit.
6. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The wall surfaces on both sides of the feed plate and the spinneret are also provided with heat insulation layers.
7. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The spinneret is processed with a positioning groove on its contact surface with the feed plate; the feed plate is processed with a positioning boss on its contact surface with the spinneret; the positioning boss is directly opposite to the positioning groove, and the two form a clearance fit relationship.
8. A meltblowing die assembly for producing hollow fibers according to claim 7, characterized in that: The positioning groove is between the material storage cavity and the air intake hole.
9. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The storage cavity is in the shape of an elongated strip and extends along the length direction of the spinneret; the upper end of the feed port is located in the middle of the upper plane of the feed plate, and the lower end of the feed port extends along the length direction of the feed plate.
10. A meltblowing die assembly for producing hollow fibers according to claim 1, characterized in that: The air guide chamber is long and extends along the length of the air plate; the air inlet channel is right-angled, one end of the air inlet channel is located on the side of the feed plate, and the other end is located at the bottom of the feed plate; the air inlet hole penetrates the spinneret in the vertical direction.