A microinjection device

Abstract

The present invention belongs to the technical field of blending and modification equipment, and specifically relates to a microinjection device for adding auxiliary materials to the main pipeline of a mixer-based mixing system. The microinjection device includes an injection sleeve with a hollow cavity, a piston coaxially mounted on the injection sleeve, a drive device for driving the piston to slide along the injection sleeve, a feed hopper connected to the hollow cavity of the injection sleeve, and an exhaust valve connected to the hollow cavity of the injection sleeve. The end of the injection sleeve is connected to a pipeline connected to the main pipeline; and an on-off valve is provided between the feed hopper and the injection sleeve. The present invention disposes a piston within the injection sleeve and a heating device outside the injection sleeve to solve the technical problem that current auxiliary material metering devices do not provide sufficient pressurization to add auxiliary materials to pipelines with high-pressure, high-viscosity melts.

Description

Technical Field

[0001] The invention belongs to the technical field of blending and modification equipment, and particularly relates to a microinjection device. Background Art

[0002] Plastic modification refers to the process of improving plastic quality through modification, such as density, hardness, precision, appearance, processability, transparency, mechanical properties, electromagnetic properties, chemical properties, corrosion resistance, aging resistance, wear resistance, thermal properties, flame retardancy, barrier properties, and cost. Plastic modification is the most effective way to reduce costs and improve performance.

[0003] Blending refers to mixing together. It is a physical method to evenly mix several materials to improve the performance of the materials. A typical example is the use of a rubber mixer in industry to evenly mix different rubbers or rubber and plastic into rubber compounds. It is also possible to add certain special properties to the polymer to change the properties of the polymer, such as conductivity.

[0004] Whether it is blending or modification, an indispensable step is the mixing of different melts. The equipment involved is the mixer and metering injection device. The mixing devices currently used in the chemical industry are static mixers or dynamic mixers. The main material metering device is generally a melt gear pump, and the auxiliary material metering device is generally a plunger pump or a melt gear pump.

[0005] However, the current problem is that the main ingredients in the mixture are high temperature (>200°), high pressure (>20Mpa), and high viscosity (>2000Pa.s), while the auxiliary materials are usually PPM (part per million)-level aqueous solutions. As a result, when the sampling melt gear pump adds the aqueous solution medium, there will be a problem of insufficient pressure. This will result in the aqueous solution medium being unable to be added to the high-pressure, high-viscosity melt pipeline, causing inconvenience to plastic modification or blending processing. Summary of the Invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a micro-injection device, in which a piston is arranged inside the injection sleeve and a heating device is arranged outside the injection sleeve to solve the technical problem that the current auxiliary material metering device is not sufficiently pressurized to add the auxiliary material to the pipeline of the high-pressure, high-viscosity melt.

[0007] To achieve the above-mentioned objectives, the technical solution of the present invention is as follows: a microinjection device, which is used to add auxiliary materials to the main pipeline of a mixing system based on a mixer, and the microinjection device includes an injection sleeve with a hollow cavity therein, a piston coaxially sleeved on the injection sleeve, a drive device for driving the piston to slide along the injection sleeve, a feeding hopper connected to the hollow cavity of the injection sleeve, and an exhaust valve connected to the hollow cavity of the injection sleeve; the end of the injection sleeve is connected to a pipeline connected to the main pipeline; and an on-off valve is provided between the feeding hopper and the injection sleeve.

[0008] Preferably, the feeding hopper is coated with a first heating device.

[0009] Preferably, the injection sleeve is coated with a second heating device.

[0010] Preferably, the driving device includes an electric cylinder and an active connector connecting the electric cylinder and the piston.

[0011] Preferably, the electric cylinder is driven by a servo motor.

[0012] Preferably, the microinjection device further comprises a pressure sensor connected to the injection sleeve and used to detect the pressure inside the injection sleeve.

[0013] Preferably, the microinjection device further comprises an injection rod for connecting the pipeline and the main pipeline, and a capillary hole is provided at the end of the injection rod extending into the main pipeline.

[0014] Preferably, the microinjection device further comprises a common base for supporting the injection sleeve and the driving device.

[0015] Preferably, the exhaust valve is provided on the injection sleeve near the end of the pipeline.

[0016] Preferably, the feeding hopper is arranged on the end of the injection sleeve away from the pipeline.

[0017] The beneficial effects of adopting the technical solution of the present invention are:

[0018] The present invention adopts a piston-type injection device to add auxiliary materials, which is convenient for pressurizing the auxiliary materials and adding the auxiliary materials into the main pipeline. By connecting a piston in an injection sleeve, connecting a pipeline to the main pipeline at the end of the injection sleeve away from the piston, connecting a feeding hopper with an on-off valve to the injection sleeve, and connecting an exhaust valve for exhausting air in the injection sleeve to the injection sleeve, the auxiliary materials are added from the feeding hopper to the injection sleeve until it is full, and the air in the injection sleeve is completely exhausted from the exhaust valve by squeezing the piston. After closing the exhaust valve and continuing to push the piston forward until the auxiliary materials fill the pipeline, and adjusting the pressure in the injection sleeve, the auxiliary materials can be added to the main pipeline. The piston squeezing facilitates increasing the pressure, so as to achieve the addition of auxiliary materials to the high-pressure main pipeline. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a schematic diagram of an embodiment of a microinjection device;

[0020] Figure 2 A schematic diagram of an injection sleeve of an embodiment of a microinjection device;

[0021] Figure 3 Schematic diagram of an injection rod of an embodiment of a microinjection device.

[0022] in, Figure 1-3 In the figure, 1-driving device, 11-electric cylinder, 12-movable connector, 2-piston, 21-piston rod, 3-feeding hopper, 31-switching valve, 32-first heating device, 4-exhaust valve, 5-injection sleeve, 51-cylinder bottom, 52-pressure measuring hole, 53-exhaust hole, 54-feeding hopper connecting hole, 55-second heating device, 6-pipeline, 7-injection rod, 71-flow channel, 72-capillary pore, 8-main pipeline. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments, and do not limit the scope of the present invention.

[0024] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended solely to facilitate and simplify the description of the present invention. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and therefore should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0025] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0026] It should be noted that the microinjection device of the present invention is applied in a mixing system based on a mixer, and is used to add auxiliary materials into the main line of the mixing system.

[0027] The specific embodiments are as follows:

[0028] Example 1, as Figure 1-3 As shown, a microinjection device includes an injection sleeve 5, a piston 2, a drive device 1, a feeding hopper 3, and an exhaust valve 4. Specifically, a hollow cavity with two ends open is coaxially provided on the injection sleeve 5; a piston 2 is inserted into the injection sleeve 5 from one end, and the piston 2 slides inside the injection sleeve 5 to adjust the pressure inside the injection sleeve 5 and extrude the auxiliary material. More specifically, a sealing ring and a guide ring are provided on the outer sleeve of the piston 2 to ensure close contact between the piston 2 and the inner wall of the injection sleeve 5. More specifically, a connecting hole is coaxially provided on the piston 2, and a piston rod 21 passes through the connecting hole. The piston rod 21 and the piston 2 are connected together by a locking nut. More specifically, a guide sleeve is provided at the end of the piston rod 21 of the injection sleeve 5 from which it protrudes, a sealing ring is provided between the guide sleeve and the injection sleeve 5, the piston rod 21 passes through the guide sleeve, and a guide ring is provided between the piston rod 21 and the guide sleeve, and a dust ring is also provided on the outside of the guide sleeve to reduce contamination of the auxiliary material in the injection sleeve 5.

[0029] Specifically, a driving device 1 is connected to the end of the piston rod 21 away from the piston 2 , for driving the piston 2 to slide back and forth in the injection sleeve 5 .

[0030] Specifically, a hopper connection hole 54 is provided on the side wall of the injection sleeve 5 near the end. The hopper connection hole 54 is in communication with the interior of the injection sleeve 5 and is connected to the feeding hopper 3 at the hopper connection hole 54. An on-off valve 31 is provided between the feeding hopper 3 and the injection sleeve 5 to close after the injection sleeve 5 is charged from the feeding hopper 3 to prevent air leakage from the injection sleeve 5.

[0031] Specifically, an exhaust hole 53 is provided on the side wall of the injection sleeve 5 away from the end of the feeding hopper connecting hole 54, and the exhaust hole 53 is communicated with the injection sleeve 5. An exhaust valve is connected to the exhaust hole 53 for exhausting the air in the injection sleeve 5.

[0032] In this embodiment, the exhaust valve is an electromagnetic exhaust valve.

[0033] Specifically, the end of the injection sleeve 5 close to the exhaust hole 53 is connected to the cylinder bottom 51, and a detachable connection is achieved by bolts.

[0034] An opening is provided at the center of the cylinder bottom 51, which communicates with the injection sleeve 5. Pipeline 6 is connected to the opening. Pipeline 6 is connected to the main line 8 of the mixing system. The auxiliary material flows from the injection sleeve 5 through pipeline 6 into the main line 8, thereby adding the auxiliary material to the main line 8.

[0035] When using the microinjection device of this embodiment, the auxiliary material is put into the feeding hopper 3 in advance, the switch valve 31 is opened to flow the auxiliary material into the injection sleeve 5, and the switch valve 31 is closed after the auxiliary material is added. The driving device 1 is started, and the piston rod 21 is pushed forward. During the process, the forward amount of the piston rod 21 is adjusted (a few threads / second), and the air in the injection sleeve 5 is slowly advanced to exhaust from the exhaust valve 4. When the auxiliary material is seen to flow out from the exhaust valve 4 or when it is confirmed that the air in the injection sleeve 5 is emptied, the exhaust valve 4 is closed, and the piston rod 21 is continued to be advanced. After the auxiliary material fills the pipeline 6, the mixing work of the mixing system is started. Since the auxiliary material in the injection sleeve 5 is squeezed out by the piston 2, it is convenient to continuously pressurize to adapt to adding the auxiliary material to the main pipeline 8 of the melt with high pressure and high viscosity. Therefore, the microinjection device is particularly suitable for the injection of PPM-level materials or high-temperature and high-pressure aqueous solution materials.

[0036] Furthermore, a first heating device 32 is coated on the outside of the feeding hopper 3 for heating the auxiliary material in the feeding hopper 3 to facilitate melting of auxiliary materials in solid or other forms so that they can flow into the injection sleeve 5 .

[0037] Furthermore, a second heating device 55 is coated on the outside of the injection sleeve 5 for heating the auxiliary material in the injection sleeve 5 to ensure the molten flow state of the auxiliary material.

[0038] Furthermore, the driving device 1 includes an electric cylinder 11 and a movable joint 12. Specifically, the end of the piston rod 21 away from the piston 2 is connected to the movable joint 12, and the other end of the movable joint 12 is connected to the electric cylinder 11 to ensure the linear movement of the piston rod 21.

[0039] In this embodiment, the electric cylinder 11 is driven by a servo motor, which can more accurately control the amount of advance of the piston rod 21 and thus more accurately control the amount of auxiliary material added.

[0040] Furthermore, a pressure measuring hole 52 is provided on the side wall of the injection sleeve 5 near the exhaust hole 53, and a pressure sensor is connected to the pressure measuring hole 52 for detecting the pressure inside the injection sleeve 5, detecting the melt state of the auxiliary material, and being able to adjust the drive device 1 according to the detected pressure to protect the drive device.

[0041] Furthermore, an injection rod 7 is provided between the pipeline 6 and the main pipeline 8. Specifically, a flow channel 71 is coaxially provided within the injection rod 7. One end of the injection rod 7 is connected to the end of the pipeline 6 away from the injection sleeve 5, and the other end is inserted into the main pipeline 8, thereby achieving communication between the main pipeline 8 and the pipeline 6. At the same time, a capillary hole 72 is provided at the end of the injection rod 7 inserted into the main pipeline 8. The capillary hole 72 is connected to the flow channel 71, thereby forming a back pressure between the main pipeline 8 and the pipeline 6, preventing the material in the main pipeline from flowing back into the injection rod.

[0042] Furthermore, the microinjection device further comprises a common base on which the injection sleeve 5 and the drive device 1 are both mounted, thereby improving the overall integration and facilitating overall transfer.

[0043] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A microinjection device for adding PPM-grade solid auxiliary materials into a main pipe (8) of a high-pressure melt greater than 20 MPa and a high-viscosity melt greater than 2000 Pa·s in a mixing system based on a mixer, characterized in that: include: An injection sleeve (5) having a hollow cavity; a piston (2) coaxially sleeved on the injection sleeve (5); A driving device (1) is used to drive the piston (2) to slide along the injection sleeve (5); a feeding hopper (3) is connected to the hollow cavity of the injection sleeve (5) through an on-off valve (31), and the feeding hopper (3) is coated with a first heating device (32) to melt the solid auxiliary material; an exhaust valve (4) is arranged at the end of the side wall of the injection sleeve (5) adjacent to the connection with the pipeline and is connected to the hollow cavity; a pipeline (6) is connected to the end of the injection sleeve (5) and is connected to the main pipeline (8); an injection rod (7) is connected to the pipeline (6) and the main pipeline (8), and a capillary hole is provided at the end of the injection rod (7) extending into the main pipeline (8); wherein the injection sleeve (5) is coated with a second heating device (55), and the exhaust valve (4) is located at the end of the injection sleeve (5) close to the pipeline (6) and is used to discharge gas when the piston (2) is pushed forward.

2. A microinjection device according to claim 1, characterized in that: The driving device (1) comprises an electric cylinder and an active connector connecting the electric cylinder and the piston (2).

3. A microinjection device according to claim 2, characterized in that: The electric cylinder is driven by a servo motor.

4. A microinjection device according to claim 1, characterized in that: It also includes a pressure sensor connected to the injection sleeve (5) and capable of detecting the pressure in the cavity in real time.

5. A microinjection device according to claim 1, characterized in that: It also comprises a common base for supporting the injection sleeve (5) and the driving device (1).

6. A microinjection device according to claim 1, characterized in that: The feeding hopper (3) is arranged on the end of the injection sleeve (5) away from the pipeline (6).

Images