Extruder discharge structure for polylactic acid foamed particle production

Abstract

The utility model belongs to extruder discharge structure improvement technical field, concretely relates to a kind of extruder discharge structure for polylactic acid foamed particle production, including cylinder, discharge screw is rotationally connected in cylinder, cylinder is fixedly connected with pressure regulating seat by multiple connecting ribs, the inside of pressure regulating seat is equipped with piston hole, the side wall of pressure regulating seat is equipped with the pressure-reducing port and booster port corresponding with piston hole respectively in left and right ends, pressure-reducing port and booster port are all through cylinder, and are sealingly connected with cylinder, piston is slidably connected in piston hole, valve core is fixedly connected on the right end surface of piston, valve core is through pressure regulating seat, and is slidably connected with pressure regulating seat, pressure regulating seat is connected with the sealing ring corresponding with valve core, cylinder is also fixed with the valve seat corresponding with valve core.The extruder discharge structure for polylactic acid foamed particle production can adjust discharge pressure, thereby guarantee the forming quality of subsequent product.

Description

Technical Field

[0001] This utility model relates to an extruder discharge structure for the production of polylactic acid foamed granules, and belongs to the technical field of extruder discharge structure improvement. Background Technology

[0002] Polylactic acid (PLA) foam granules are widely used in packaging, 3D printing, and medical materials due to their environmental friendliness, biodegradability, and cushioning properties. In the production process of PLA foam granules, the molten material extruded from the extruder needs to be cut into shape using a pelletizing device. Traditional extruders lack a pressure regulating structure at the discharge end, making it impossible to adjust the discharge pressure. This leads to pressure fluctuations in the melt conveyed to the pelletizing device at the underwater pelletizing die, resulting in uneven geometric dimensions of the cut foam granules and affecting the product's molding quality. Utility Model Content

[0003] In view of the shortcomings of the prior art, the technical problem to be solved by this utility model is to provide an extruder discharge structure for the production of polylactic acid foamed granules with adjustable discharge pressure.

[0004] The extruder discharge structure for polylactic acid foam granule production described in this utility model includes a cylinder, a discharge screw rotatably connected inside the cylinder, and a pressure regulating seat fixedly connected inside the cylinder by multiple connecting ribs. The pressure regulating seat has a piston hole inside, and pressure reducing port and pressure increasing port corresponding to the piston hole are respectively provided at the left and right ends of the side wall of the pressure regulating seat. Both the pressure reducing port and the pressure increasing port penetrate the cylinder and are sealed to the cylinder. A piston is slidably connected inside the piston hole, and a valve core is fixedly connected to the right end face of the piston. The valve core penetrates the pressure regulating seat and is slidably connected to the pressure regulating seat. A sealing ring corresponding to the valve core is connected to the pressure regulating seat. A valve seat corresponding to the valve core is also fixed inside the cylinder.

[0005] Furthermore, a pressure stabilizing plate is fixedly connected inside the cylinder. The pressure stabilizing plate is located between the discharge screw and the pressure regulating seat. The left end of the pressure stabilizing plate is provided with multiple main channels, and the right end of the pressure stabilizing plate is provided with multiple branch channels corresponding to each main channel.

[0006] Furthermore, the left end of the voltage regulating seat is conical.

[0007] Furthermore, there are three connecting ribs, which are evenly distributed in a circle on the outside of the pressure regulating seat.

[0008] Furthermore, the inner cavity of the valve seat is funnel-shaped.

[0009] Furthermore, a left limiting ring is fixedly connected inside the piston hole, and the left limiting ring is located between the pressure reducing port and the piston.

[0010] Furthermore, a right limiting ring is fixedly connected inside the piston hole, and the right limiting ring is located between the piston and the booster port.

[0011] Working principle and process:

[0012] In use, both the pressure-reducing port and the pressure-boosting port are connected to the hydraulic system. The discharge screw conveys the foamed granule melt to the pressure stabilizing plate. The pressure stabilizing plate adopts a large-inlet and small-outlet design, which can effectively reduce the discharge pressure, thereby making the melt pressure more stable. The melt flowing out of the pressure stabilizing plate continues to flow to the right under the guidance of the pressure regulating seat through the gap between the pressure regulating seat and the cylinder, and flows out through the gap between the valve core and the valve seat and is conveyed to the underwater pelletizing die. When the pressure at the underwater pelletizing die is too high, the hydraulic system can control the inlet of liquid at the pressure-reducing port and the outlet of liquid at the pressure-boosting port, thereby causing the piston to move to the right, which in turn drives the valve core to move to the right, reducing the gap between the valve core and the valve seat, thus reducing the discharge pressure. When the pressure at the underwater pelletizing die is too low, the hydraulic system can control the inlet of liquid at the pressure-boosting port and the outlet of liquid at the pressure-reducing port, thereby causing the piston to move to the left, which in turn drives the valve core to move to the left, increasing the gap between the valve core and the valve seat, thus increasing the discharge pressure.

[0013] The advantages of this utility model compared with the prior art are:

[0014] The extruder discharge structure for producing polylactic acid foamed granules described in this invention allows for adjustment of the discharge pressure, thereby ensuring the molding quality of subsequent products. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model;

[0016] Figure 2 yes Figure 1 A magnified view of point M in the middle.

[0017] In the diagram: 1. Cylinder; 2. Discharge screw; 3. Pressure stabilizing plate; 4. Main channel; 5. Branch channel; 6. Pressure regulating seat; 7. Connecting rib; 8. Left limit ring; 9. Pressure reducing port; 10. Piston; 11. Pressure increasing port; 12. Valve seat; 13. Valve core; 14. Sealing ring; 15. Right limit ring. Detailed Implementation

[0018] The embodiments of this utility model will be further described below with reference to the accompanying drawings:

[0019] Example 1:

[0020] like Figure 1 , Figure 2As shown, the extruder discharge structure for polylactic acid foamed granule production of this utility model includes a cylinder 1, a discharge screw 2 rotatably connected inside the cylinder 1, and a pressure regulating seat 6 fixedly connected inside the cylinder 1 by multiple connecting ribs 7. The pressure regulating seat 6 has a piston hole inside, and the left and right ends of the side wall of the pressure regulating seat 6 are respectively provided with a pressure reducing port 9 and a pressure increasing port 11 corresponding to the piston hole. Both the pressure reducing port 9 and the pressure increasing port 11 penetrate the cylinder 1 and are sealed to the cylinder 1. A piston 10 is slidably connected inside the piston hole, and a valve core 13 is fixedly connected to the right end face of the piston 10. The valve core 13 penetrates the pressure regulating seat 6 and is slidably connected to the pressure regulating seat 6. A sealing ring 14 corresponding to the valve core 13 is connected to the pressure regulating seat 6. A valve seat 12 corresponding to the valve core 13 is also fixed inside the cylinder 1.

[0021] In use, both the pressure reducing port 9 and the pressure boosting port 11 are connected to the hydraulic system. The discharge screw 2 transports the foamed granule melt to the pressure regulating seat 6, and then continues to flow to the right through the gap between the pressure regulating seat 6 and the cylinder 1. It then flows out through the gap between the valve core 13 and the valve seat 12 and is transported to the underwater pelletizing die. When the pressure at the underwater pelletizing die is too high, the hydraulic system can control the inlet of liquid at the pressure reducing port 9 and the outlet of liquid at the pressure boosting port 11, which will cause the piston 10 to move to the right, thereby driving the valve core 13 to move to the right and reducing the gap between the valve core 13 and the valve seat 12, thus reducing the discharge pressure. When the pressure at the underwater pelletizing die is too low, the hydraulic system can control the inlet of liquid at the pressure boosting port 11 and the outlet of liquid at the pressure reducing port 9, which will cause the piston 10 to move to the left, thereby driving the valve core 13 to move to the left and increasing the gap between the valve core 13 and the valve seat 12, thus increasing the discharge pressure.

[0022] Example 2:

[0023] like Figure 1 , Figure 2 As shown, based on Example 1,

[0024] Furthermore, a pressure stabilizing plate 3 is fixedly connected inside the cylinder 1. The pressure stabilizing plate 3 is located between the discharge screw 2 and the pressure regulating seat 6. The left end of the pressure stabilizing plate 3 is provided with multiple main channels 4, and the right end of the pressure stabilizing plate 3 is provided with multiple branch channels 5 corresponding to each main channel 4. Since the pressure stabilizing plate 3 adopts a large-mouth inlet and small-mouth outlet method, it can effectively reduce the discharge pressure, thereby making the melt pressure more stable.

[0025] Furthermore, the left end of the pressure regulating seat 6 is conical, which can guide the melt and facilitate the melt to flow out through the gap between the pressure regulating seat 6 and the cylinder 1.

[0026] Furthermore, there are three connecting ribs 7, which are evenly distributed circumferentially on the outer side of the pressure regulating seat 6. The structural layout is reasonable, ensuring both the structural stability of the pressure regulating seat 6 and the smooth flow of the melt.

[0027] Furthermore, the inner cavity of the valve seat 12 is funnel-shaped to facilitate the flow of the melt.

[0028] Furthermore, a left limiting ring 8 is fixedly connected inside the piston hole, and the left limiting ring 8 is located between the pressure reducing port 9 and the piston 10. The left limiting ring 8 can limit the piston 10, effectively preventing the piston 10 from blocking the pressure reducing port 9 when pressurizing.

[0029] Furthermore, a right limiting ring 15 is fixedly connected inside the piston hole, and the right limiting ring 15 is located between the piston 10 and the pressure boosting port 11. The right limiting ring 15 can limit the piston 10, effectively preventing the piston 10 from blocking the pressure boosting port 11 when the pressure is reduced.

[0030] It should be noted that in the description of this utility model, the terms "left" and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not require that this utility model must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

Claims

1. A discharge structure for an extruder used in the production of polylactic acid foamed granules, comprising a cylinder (1) and a discharge screw (2) rotatably connected inside the cylinder (1), characterized in that: A pressure regulating seat (6) is fixedly connected inside the cylinder (1) by multiple connecting ribs (7). The pressure regulating seat (6) has a piston hole inside. The left and right ends of the side wall of the pressure regulating seat (6) are respectively provided with a pressure reducing port (9) and a pressure increasing port (11) corresponding to the piston hole. The pressure reducing port (9) and the pressure increasing port (11) both penetrate the cylinder (1) and are sealed to the cylinder (1). A piston (10) is slidably connected inside the piston hole. A valve core (13) is fixedly connected to the right end face of the piston (10). The valve core (13) penetrates the pressure regulating seat (6) and is slidably connected to the pressure regulating seat (6). A sealing ring (14) corresponding to the valve core (13) is connected on the pressure regulating seat (6). A valve seat (12) corresponding to the valve core (13) is also fixed inside the cylinder (1).

2. The extruder discharge structure for producing polylactic acid foamed granules according to claim 1, characterized in that: The cylinder (1) is also fixedly connected to a pressure stabilizing plate (3). The pressure stabilizing plate (3) is located between the discharge screw (2) and the pressure regulating seat (6). The left end of the pressure stabilizing plate (3) is provided with multiple main channels (4), and the right end of the pressure stabilizing plate (3) is provided with multiple branch channels (5) corresponding to each main channel (4).

3. The extruder discharge structure for producing polylactic acid foamed granules according to claim 1, characterized in that: The left end of the pressure regulating seat (6) is conical.

4. The extruder discharge structure for producing polylactic acid foamed granules according to claim 1, characterized in that: There are three connecting ribs (7), which are evenly distributed in a circle on the outside of the pressure regulating seat (6).

5. The extruder discharge structure for producing polylactic acid foamed granules according to claim 1, characterized in that: The inner cavity of the valve seat (12) is funnel-shaped.

6. The extruder discharge structure for producing polylactic acid foamed granules according to any one of claims 1 to 5, characterized in that: A left limiting ring (8) is fixedly connected inside the piston hole, and the left limiting ring (8) is located between the pressure reducing port (9) and the piston (10).

7. The extruder discharge structure for producing polylactic acid foamed granules according to claim 6, characterized in that: A right limiting ring (15) is fixedly connected inside the piston hole, and the right limiting ring (15) is located between the piston (10) and the pressure port (11).

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