Polyurethane supercritical foaming 3D printer

Abstract

The invention belongs to the field of supercritical foaming, and provides a polyurethane supercritical foaming 3D printer which comprises a multidirectional sliding mechanism, a mixing printing unit is mounted on the multidirectional sliding mechanism, a gas injection unit is mounted on the left side of the multidirectional sliding mechanism, and a plasticizing unit is mounted on the right side of the multidirectional sliding mechanism. The multidirectional sliding mechanism is provided with two groups of pipeline limiting assemblies which are respectively matched with the gas injection unit and the plasticizing unit for use; according to the invention, simultaneous output or independent output can be realized through a plurality of pressure regulating valves, design requirements of different structure positions are inconsistent, and for part of functional finished products, the nozzle is required to form molten resin with foaming pore structures in different states through different calibers and shapes; the mixing printing unit is driven by the multidirectional sliding mechanism to move in the X / Y / Z axial direction, 3D printing is carried out according to the design drawing requirement and the structure size requirement, a final finished product is formed, a traditional mold forming mode is abandoned, and meanwhile the personalized customization requirement for stable precision is met.

Description

Technical Field

[0001] The invention belongs to the field of supercritical foaming, in particular to a polyurethane supercritical foaming 3D printer. Background Art

[0002] A supercritical foaming fluid (such as CO2 or N2) is dissolved in a polymer (such as polyurethane) under high pressure. Rapid decompression or heating triggers foaming, forming a microporous structure. This process can produce highly resilient, lightweight materials, often used in shoe soles, packaging, and other fields.

[0003] In the existing technology, foam materials are mainly injection-molded through injection molding machines to achieve the production of high-rebound, lightweight soles, packaging and other objects. However, the existing injection molding machines mainly rely on molds to shape the materials. However, due to the fixed shape of the molds, different products require different molds, the investment cost of the molds is high, and it is difficult to meet personalized customization needs. In addition, the molds need to be continuously cleaned during the continuous production process, and their production efficiency needs to be improved. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a polyurethane supercritical foaming 3D printer to solve the problems raised in the above background technology.

[0005] A polyurethane supercritical foaming 3D printer, comprising a multi-directional sliding mechanism, a mixing and printing unit mounted on the multi-directional sliding mechanism, a gas injection unit mounted on the left side of the multi-directional sliding mechanism, a plasticizing unit mounted on the right side of the multi-directional sliding mechanism, two sets of pipeline limit assemblies mounted on the multi-directional sliding mechanism, one for each of the gas injection unit and the other for the plasticizing unit, and a cleaning mechanism mounted on the rear side of the multi-directional sliding mechanism;

[0006] The mixing and printing unit includes a rod-shaped mixing bin, in which a feeding screw is rotatably installed in the inner cavity of the rod-shaped mixing bin, a second motor is installed on the top surface of the rod-shaped mixing bin, and the rotating end of the second motor is rotatably connected to the upper end of the feeding screw. A nitrogen pumping head is provided on the left outer wall of the rod-shaped mixing bin, and a plasticizing feed port is provided on the right outer wall of the rod-shaped mixing bin. Several pressure regulating valves are installed on the bottom surface of the rod-shaped mixing bin, and a nozzle is installed at the discharge end of the pressure regulating valve. A pin mixing section is provided between the feeding screw and the inner cavity of the rod-shaped mixing bin.

[0007] Preferably, the multi-directional sliding mechanism includes a base, a printing table that can slide back and forth along the Z-axis direction is installed on the top surface of the base, Y-axis driving arms are symmetrically fixedly installed in the middle of both ends of the top surface of the base, an X-axis driving arm that can slide back and forth along the Y-axis direction is installed between the two Y-axis driving arms, and a sliding seat that can slide back and forth along the X-axis direction is installed on the front wall surface of the X-axis driving arm.

[0008] Preferably, the rod-shaped mixing bin is fixedly mounted on the middle portion of the sliding seat.

[0009] Preferably, the cleaning mechanism includes two support seats symmetrically installed on the top surface of the rear end of the base, a roller brush is rotatably installed between the two support seats, a motor mounting seat is installed on the outer wall surface of one side of the support seat, a first motor is installed on the motor mounting seat, and the rotating end of the first motor is fixedly installed on one end of the roller brush.

[0010] Preferably, the two groups of pipeline limiting assemblies both include a sliding groove opened on the front wall surface of the Y-direction driving arm on the same side, and the sliding groove is slidably installed with a connecting seat, and the connecting seat is fixedly installed on the front wall surface at the end of the X-direction driving arm on the same side, and two guide wheels are installed on the connecting seat in an upper and lower symmetrical rotation.

[0011] Preferably, the gas injection unit includes a nitrogen booster, a nitrogen bottle is installed at the air inlet of the nitrogen booster, and an injection pipe is installed at the air outlet of the nitrogen booster, and the outlet end of the injection pipe passes through the two guide wheels on the left and is connected to the nitrogen pumping head.

[0012] Preferably, the plasticizing unit comprises a polyurethane plasticizing machine, the discharge end of the polyurethane plasticizing machine is connected to a constant temperature pipe, and the discharge end of the constant temperature pipe passes through two guide wheels on the right side and is connected to the plasticizing feed port.

[0013] Preferably, the spacing between the two guide wheels on the left connecting seat matches the diameter of the gas injection pipe, and the spacing between the two guide wheels on the right connecting seat matches the diameter of the constant temperature pipe.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] 1. The present invention can output simultaneously or independently through multiple pressure regulating valves. Different structural positions have different design requirements. For some functional finished products, the nozzles are required to form molten resin with foaming pore structures in different states through different calibers and shapes. The mixing and printing unit is driven by a multi-directional sliding mechanism to move along the X / Y / Z axes. 3D printing is performed according to the requirements of the design drawings and structural dimensions to form the final product. While abandoning the traditional mold forming method, it realizes the personalized customization requirements of stable precision.

[0016] 2. The present invention drives the printing table to slide backward after printing is completed. During the sliding process, the first motor drives the roller brush to rotate, thereby quickly cleaning the polyurethane material remaining on the surface of the printing table, thereby avoiding affecting the continuous progress of production and improving production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 It is a schematic structural diagram of the multi-directional sliding mechanism of the present invention;

[0019] Figure 3 It is a cross-sectional view of the mixing and printing unit of the present invention;

[0020] Figure 4 This is an enlarged schematic diagram of the structure at point A of the present invention;

[0021] Figure 5 It is a schematic structural diagram of the cleaning mechanism of the present invention;

[0022] Figure 6 Schematic diagram of the gas injection unit structure of the present invention;

[0023] Figure 7 Schematic diagram of the plasticizing unit structure of the present invention.

[0024] In the picture:

[0025] 1. Multi-directional sliding mechanism; 101. Base; 102. Printing table; 103. Y-axis driving arm; 104. X-axis driving arm; 105. Sliding seat;

[0026] 2. Cleaning mechanism; 201. Support base; 202. Roller brush; 203. Motor mounting base; 204. First motor;

[0027] 3. Gas injection unit; 301. Nitrogen booster; 302. Nitrogen cylinder; 303. Gas injection pipe;

[0028] 4. Plasticizing unit; 401. Polyurethane plasticizing machine; 402. Constant temperature pipeline;

[0029] 5. Mixing and printing unit; 501. Rod-shaped mixing chamber; 502. Feeding screw; 503. Second motor; 504. Nitrogen pump head; 505. Plasticizing feed port; 506. Pressure regulating valve; 507. Nozzle;

[0030] 6. Pipeline limit assembly; 601. Sliding groove; 602. Connecting seat; 603. Guide wheel. DETAILED DESCRIPTION

[0031] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.

[0032] Example 1:

[0033] Reference Attachment Figure 1 To the attached Figure 7As shown, a polyurethane supercritical foaming 3D printer includes a multi-directional sliding mechanism 1, a mixing and printing unit 5 is installed on the multi-directional sliding mechanism 1, a gas injection unit 3 is installed on the left side of the multi-directional sliding mechanism 1, a plasticizing unit 4 is installed on the right side of the multi-directional sliding mechanism 1, two sets of pipeline limit assemblies 6 are installed on the multi-directional sliding mechanism 1, which are respectively matched with the gas injection unit 3 and the plasticizing unit 4, and a cleaning mechanism 2 is installed on the rear side of the multi-directional sliding mechanism 1;

[0034] The mixing and printing unit 5 includes a rod-shaped mixing chamber 501, in which a feeding screw 502 is rotatably installed in the inner cavity of the rod-shaped mixing chamber 501, a second motor 503 is installed on the top surface of the rod-shaped mixing chamber 501, and the rotating end of the second motor 503 is rotatably connected to the upper end of the feeding screw 502, a nitrogen pumping head 504 is provided on the left outer wall of the rod-shaped mixing chamber 501, and a plasticizing feed port 505 is provided on the right outer wall of the rod-shaped mixing chamber 501, a plurality of pressure regulating valves 506 are installed on the bottom surface of the rod-shaped mixing chamber 501, and a nozzle 507 is installed at the discharge end of the pressure regulating valve 506, and a pin mixing section is provided between the feeding screw 502 and the inner cavity of the rod-shaped mixing chamber 501;

[0035] The multi-directional sliding mechanism 1 includes a base 101, on the top surface of which is mounted a printing table 102 that can slide back and forth along the Z-axis. Y-axis driving arms 103 are symmetrically fixedly mounted in the middle of both ends of the top surface of the base 101. An X-axis driving arm 104 that can slide back and forth along the Y-axis is mounted between the two Y-axis driving arms 103. A sliding seat 105 that can slide back and forth along the X-axis is mounted on the front wall of the X-axis driving arm 104.

[0036] The rod-shaped mixing chamber 501 is fixedly mounted in the middle of the sliding seat 105;

[0037] The gas injection unit 3 includes a nitrogen booster 301, a nitrogen bottle 302 is installed at the gas inlet of the nitrogen booster 301, and a gas injection pipe 303 is installed at the gas outlet of the nitrogen booster 301. The gas outlet end of the gas injection pipe 303 passes through the two guide wheels 603 on the left side and is connected to the nitrogen pumping head 504;

[0038] The plasticizing unit 4 includes a polyurethane plasticizing machine 401, the discharge end of the polyurethane plasticizing machine 401 is connected to a constant temperature pipe 402, and the discharge end of the constant temperature pipe 402 passes through two guide wheels 603 on the right side and is connected to the plasticizing feed port 505;

[0039] As can be seen from the above, the foaming material resin particles are placed in the polyurethane plasticizing machine 401 and heated to 180-300 degrees [adaptively adjusted according to demand], and transported to the plasticizing feed port 505 through the constant temperature pipe 402, and then enter the inner cavity of the rod-shaped mixing chamber 501;

[0040] The nitrogen cylinder 302 provides a gas source for the nitrogen booster 301. The gas is precisely controlled to be supercritical nitrogen. After being pressurized, maintained at a constant pressure, and regulated, the gas is transported to the nitrogen pumping head 504 through the gas injection pipe 303 and then input into the inner cavity of the rod-shaped mixing chamber 501 through the nitrogen pumping head 504.

[0041] The second motor 503 drives the feeding screw 502 to rotate at high speed. At the same time, the pin mixing section between the rod-shaped mixing chamber 501 and the feeding screw 502 is used to quickly mix the molten polyurethane fluid and high-pressure nitrogen, thereby generating a supercritical fluid [pressure ≥ 250 bar, temperature 31.1 ± 5°C];

[0042] After passing through the pressure regulating valve 506, the supercritical fluid is rapidly and continuously released in pulses [pressure relief rate ≥ 50 bar / ms] and sprayed onto the printing table 102 through the nozzle 507, thereby causing the supercritical fluid to rapidly expand to form a dense and uniform pore-shaped polyurethane fluid, and then quickly form a finished product on the printing table 102;

[0043] It should be noted here that: several pressure regulating valves 506 can output simultaneously or independently, and the design requirements of different structural positions are inconsistent. For some functional finished products, the nozzle 507 is required to form molten resin with foaming pore structure in different states through different caliber sizes and shapes [round holes and flat holes]. The mixing and printing unit 5 is driven by the multi-directional sliding mechanism 1 to move along the X / Y / Z axis, and 3D printing is performed according to the requirements of the design drawings and structural dimensions. Thermal expansion and contraction [2% shrinkage rate] are taken into consideration during the design to form the final product. While abandoning the traditional mold forming method, stable and precise personalized customization needs are achieved.

[0044] Example 2:

[0045] Reference Attachment Figure 1 To the attached Figure 7 As shown, the cleaning mechanism 2 includes two support bases 201 symmetrically mounted on the top surface of the rear end of the base 101, a roller brush 202 is rotatably mounted between the two support bases 201, a motor mounting base 203 is mounted on the outer wall of one side of the support base 201, a first motor 204 is mounted on the motor mounting base 203, and the rotating end of the first motor 204 is fixedly mounted to one end of the roller brush 202;

[0046] After printing is completed, the printing table 102 is driven to slide backward. During the sliding process, the first motor 204 drives the roller brush 202 to rotate, thereby quickly cleaning the polyurethane material remaining on the surface of the printing table 102, thereby avoiding affecting the continuous progress of production and improving production efficiency.

[0047] The two sets of pipeline limiting components 6 each include a sliding groove 601 provided on the front wall of the Y-direction driving arm 103 on the same side. A connecting seat 602 is slidably mounted on the sliding groove 601. The connecting seat 602 is fixedly mounted on the front wall of the end of the X-direction driving arm 104 on the same side. Two guide wheels 603 are symmetrically mounted on the connecting seat 602 for vertical rotation.

[0048] The spacing between the two guide wheels 603 on the left connecting seat 602 matches the diameter of the gas injection pipe 303, and the spacing between the two guide wheels 603 on the right connecting seat 602 matches the diameter of the constant temperature pipe 402;

[0049] On it, two sets of pipeline limiting components 6 are used to limit and clamp the gas injection pipe 303 and the constant temperature pipe 402, so as to prevent the gas injection pipe 303 and the constant temperature pipe 402 from being drawn onto the printing table 102 when the X-axis driving arm 104 moves, thereby affecting the rapid progress of printing.

[0050] The embodiments of the present invention are provided for the purpose of illustration and description. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations of the present invention. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A polyurethane supercritical foaming 3D printer, characterized by: The invention comprises a multi-directional sliding mechanism (1), a mixing and printing unit (5) is installed on the multi-directional sliding mechanism (1), an air injection unit (3) is installed on the left side of the multi-directional sliding mechanism (1), a plasticizing unit (4) is installed on the right side of the multi-directional sliding mechanism (1), two sets of pipeline limit assemblies (6) respectively matched with the air injection unit (3) and the plasticizing unit (4) are installed on the multi-directional sliding mechanism (1), and a cleaning mechanism (2) is installed on the rear side of the multi-directional sliding mechanism (1); The mixing and printing unit (5) comprises a rod-shaped mixing bin (501), a feeding screw (502) is rotatably installed in the inner cavity of the rod-shaped mixing bin (501), a second motor (503) is installed on the top surface of the rod-shaped mixing bin (501), the rotating end of the second motor (503) is rotatably connected to the upper end of the feeding screw (502), a nitrogen pumping head (504) is provided on the left outer wall surface of the rod-shaped mixing bin (501), a plasticizing feed port (505) is provided on the right outer wall surface of the rod-shaped mixing bin (501), a plurality of pressure regulating valves (506) are installed on the bottom surface of the rod-shaped mixing bin (501), a nozzle (507) is installed at the discharge end of the pressure regulating valve (506), and a pin mixing section is provided between the feeding screw (502) and the inner cavity of the rod-shaped mixing bin (501).

2. A polyurethane supercritical foaming 3D printer as claimed in claim 1, characterized in that: The multi-directional sliding mechanism (1) comprises a base (101), a printing table (102) capable of reciprocatingly sliding along the Z-axis direction is installed on the top surface of the base (101), Y-direction driving arms (103) are symmetrically fixedly installed in the middle of both ends of the top surface of the base (101), an X-direction driving arm (104) capable of reciprocatingly sliding along the Y-axis direction is installed between the two Y-direction driving arms (103), and a sliding seat (105) capable of reciprocatingly sliding along the X-axis direction is installed on the front wall surface of the X-direction driving arm (104).

3. A polyurethane supercritical foaming 3D printer as claimed in claim 2, characterized in that: The rod-shaped mixing chamber (501) is fixedly mounted on the middle portion of the sliding seat (105).

4. A polyurethane supercritical foaming 3D printer as claimed in claim 2, characterized in that: The cleaning mechanism (2) comprises two support seats (201) symmetrically mounted on the top surface of the rear end of the base (101); a roller brush (202) is rotatably mounted between the two support seats (201); a motor mounting seat (203) is mounted on the outer wall surface of one side of the support seat (201); a first motor (204) is mounted on the motor mounting seat (203); and a rotating end of the first motor (204) is fixedly mounted to one end of the roller brush (202).

5. A polyurethane supercritical foaming 3D printer as claimed in claim 3, characterized in that: The two groups of pipeline limiting components (6) both include a sliding groove (601) provided on the front wall surface of the Y-direction driving arm (103) on the same side, and a connecting seat (602) is slidably mounted on the sliding groove (601). The connecting seat (602) is fixedly mounted on the front wall surface at the end of the X-direction driving arm (104) on the same side, and two guide wheels (603) are symmetrically mounted on the connecting seat (602) for vertical rotation.

6. A polyurethane supercritical foaming 3D printer as claimed in claim 4, characterized in that: The gas injection unit (3) comprises a nitrogen booster (301), a nitrogen bottle (302) is installed at the gas inlet of the nitrogen booster (301), a gas injection pipe (303) is installed at the gas outlet of the nitrogen booster (301), and the gas outlet end of the gas injection pipe (303) passes through two guide wheels (603) on the left side and is connected to a nitrogen pumping head (504).

7. A polyurethane supercritical foaming 3D printer as claimed in claim 6, characterized in that: The plasticizing unit (4) comprises a polyurethane plasticizing machine (401), the discharge end of the polyurethane plasticizing machine (401) is connected to a constant temperature pipe (402), and the discharge end of the constant temperature pipe (402) passes through two right guide wheels (603) and is connected to a plasticizing feed port (505).

8. A polyurethane supercritical foaming 3D printer as claimed in claim 7, characterized in that: The spacing between the two guide wheels (603) on the left connecting seat (602) matches the diameter of the gas injection pipe (303), and the spacing between the two guide wheels (603) on the right connecting seat (602) matches the diameter of the constant temperature pipe (402).

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