Injection molding mold based on pipette tip

Abstract

The injection molding mold comprises a forming mold body, the forming mold body comprises a lower mold set and an upper mold set, a cavity injection molding assembly used for injection molding is arranged in the lower mold set, the cavity injection molding assembly comprises a cavity mold, and a cold flow groove used for accelerating cooling molding of a molded part is formed in the cavity mold; a flow guide mechanism is arranged in the cavity die, a hot runner is arranged on one side of the flow guide mechanism, a pouring head mechanism is arranged on the hot runner and movably abuts against the inner side of the cavity die, die pressing assemblies for driving the flow guide mechanism to ascend and descend are symmetrically arranged on the two sides of the lower die set correspondingly, and each die pressing assembly comprises a driving part and a limiting mechanism. The limiting mechanism is arranged on one side of the lower module. Therefore, the movable pouring head mechanism is arranged in the lower die set, raw materials are prevented from overflowing while the feeding pressure is guaranteed through seamless attachment in the pouring head mechanism, rapid separation is achieved during forming, it is guaranteed that the tip part is free of deformation and damage, and the overall quality of a formed part is effectively guaranteed.

Description

Technical Field

[0001] This application relates to the technical field of injection molding dies for pipette tips, and more particularly to an injection molding die based on a pipette tip. Background Technology

[0002] Pipettes, commonly used in laboratories and biomedical fields for micro-liquid transfer, are typically manufactured using plastic injection molding due to their need for high precision and low adhesion. Their structural characteristics include a pointed bottom (tip) and a wide top (body), forming an asymmetrical frustum-shaped structure. This unique structure leads to significant differences in cooling rates between different parts during injection molding—the tip, being smaller and having a relatively larger heat dissipation area, cools much faster than the larger, slower-dissipating body. If the injection mold's cooling system is not optimized to account for this difference, or if the demolding timing is improperly controlled, the tip may not fully cool and may stick to the mold, or break or deform during demolding due to localized stress concentration, severely impacting product yield and performance.

[0003] Traditional pipette tip injection molds typically employ a universal design, with the gating mechanism often being fixed or an integral lifting structure. After injection molding, it is necessary to wait for the entire part to solidify before the mold can be opened and demolded, which can lead to problems such as tearing or breakage of the tip due to excessive solidification or excessive contact with the mold. Summary of the Invention

[0004] This application aims to at least partially address one of the technical problems in the related art.

[0005] Therefore, the purpose of this application is to propose an injection molding mold based on a pipette tip, which adopts a movable gating mechanism in the lower mold assembly. The gating mechanism fits seamlessly to ensure feeding pressure while preventing material overflow. It can also quickly separate during molding to ensure that the tip is free from deformation and damage, thus effectively ensuring the overall quality of the molded part.

[0006] To achieve the above objectives, this application proposes an injection molding die based on a pipette tip, comprising a molding die, which includes a lower die assembly and an upper die assembly. The lower die assembly has a cavity injection molding component for injection molding, the cavity injection molding component includes a cavity mold, the cavity mold has a cold runner for accelerating the cooling and molding of the molded part, the cavity mold has a flow guiding mechanism, a hot runner is provided on one side of the flow guiding mechanism, a gating mechanism is provided on the hot runner, and the gating mechanism is movably abutting against the inside of the cavity mold; on both sides of the lower die assembly are symmetrically provided compression molding assemblies for driving the flow guiding mechanism to move up and down, the compression molding assembly includes a driving component and a limiting mechanism, the driving component is provided on one side of the lower die assembly, the limiting mechanism is provided on one side of the lower die assembly, and the driving component is abutting against the limiting mechanism.

[0007] In addition, the injection mold based on the pipette tip proposed in the above application may also have the following additional technical features: Specifically, it also includes a positioning component, which includes a fixed template disposed on one side of the cavity mold, a movable plate disposed between the fixed template and the cavity mold, and the hot runner disposed on the side of the movable plate away from the fixed template. A reset component is provided between the fixed template and the movable plate, and extension plates are symmetrically disposed on both sides of the movable plate along the X-axis.

[0008] Specifically, the gating mechanism includes a main gating pipe, a stop block, and an overflow prevention part, wherein the main gating pipe is disposed on the hot runner; the stop block is disposed on the main gating pipe; and the overflow prevention part is disposed at the bottom end of the cavity mold, and the overflow prevention part and the main gating pipe are in contact connection.

[0009] Specifically, the flow guiding mechanism includes an outer movable flow guiding tube, an inner fixed flow guiding tube, and a scraper collar, wherein the inner fixed flow guiding tube is disposed inside the cavity mold; the outer movable flow guiding tube is movably sleeved outside the inner fixed flow guiding tube; the scraper collar is disposed inside the outer movable flow guiding tube and is sleeved outside the inner fixed flow guiding tube.

[0010] Specifically, the limiting mechanism includes an outer fixing frame and an inner limiting block, wherein the outer fixing frame is disposed on one side of the extension plate; and the inner limiting block is disposed inside the outer fixing frame.

[0011] Specifically, the output end of the driving component is connected to a movable push rod, the movable push rod and the inner limiting block are in abutting connection, and the inner limiting block and the movable push rod are respectively provided with matching inclined end faces on their opposite end faces.

[0012] Specifically, the fixed template has a positioning rod on the side near the movable plate, and one side of the positioning rod is connected to the cavity mold; the movable plate has a positioning pin on the side away from the fixed template, and the positioning pin is movably inserted into the cavity mold.

[0013] Specifically, the outer side of the top wall port of the main pouring pipe is provided with an inwardly inclined end face, and the bottom wall of the anti-overflow part is seamlessly attached to the inwardly inclined end face.

[0014] Compared with the prior art, the beneficial effects of the injection molding mold based on the pipette tip in this application are as follows: A movable plate is set in the lower module, and the sprue mechanism and flow guiding mechanism move with the movable plate. The sprue mechanism can be separately controlled during the injection molding process of the pipette. The main sprue and the tip are separated during the injection molding stage of the pipette, thereby preventing problems such as tearing and breakage due to excessive cooling and solidification. The anti-overflow part and the inner inclined end face in the sprue mechanism are seamlessly connected to ensure the injection material delivery pressure and prevent the injection material from overflowing. This ensures sufficient material supply during injection molding by the pipette and guarantees the overall quality of the molded parts.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the structure of this application; Figure 2 This is a schematic diagram of the positioning component structure in this application; Figure 3 This is a schematic diagram of the gating mechanism structure in this application; Figure 4 This is a schematic diagram of the inclined end face structure within this application; Figure 5 This is a schematic diagram of the flow guiding mechanism structure in this application; Figure 6 This is a schematic diagram of the connection structure between the module and the core template in this application; Figure 7 This is a schematic diagram of the core template structure of this application.

[0017] As shown in the figure: 10. Molding mold; 101. Lower mold assembly; 102. Upper mold assembly; 103. Core template; 20. Compression molding assembly; 201. Driving component; 202. Limiting mechanism; 2021. External fixed frame; 2022. Internal limiting block; 30. Cavity injection assembly; 301. Cavity mold; 302. Cold runner; 303. Hot runner; 304. Sprue mechanism; 3041. Main sprue; 3042. Stop block; 3043. Overflow prevention part; 3044. Inner inclined end face; 305. Guide mechanism; 3051. External movable guide tube; 3052. Internal fixed guide tube; 3053. Scraper collar; 40. Positioning assembly; 401. Fixed template; 402. Reset component; 403. Movable plate; 404. Positioning rod; 405. Positioning pin; 406. Extension plate. Detailed Implementation

[0018] Embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application. Rather, embodiments of this application include all variations, modifications, and equivalents falling within the appended spirit and connotation.

[0019] The following describes an embodiment of the injection molding die based on a pipette tip, with reference to the accompanying drawings.

[0020] like Figure 1-7 As shown, the injection molding mold based on the pipette tip in this embodiment includes a molding mold 10, which includes a lower mold assembly 101 and an upper mold assembly 102. The upper mold assembly 102 is provided with a core template 103, and the lower mold assembly 101 is provided with a cavity mold 301 that matches the core template 103. The upper mold assembly 102 and the lower mold assembly 101 are respectively installed on the injection molding equipment drive in the prior art. The upper mold assembly 102 is moved by the injection molding equipment drive to complete the mold closing, mold opening, injection molding, and demolding of the molded part.

[0021] The lower mold 101 is provided with a cavity injection molding assembly 30 for injection molding. The cavity injection molding assembly 30 includes a cavity mold 301. The cavity mold 301 is provided with a cold runner 302 for accelerating the cooling and molding of the molded part. The cavity mold 301 is provided with a flow guiding mechanism 305. A hot runner 303 is provided on one side of the flow guiding mechanism 305. A gating mechanism 304 is provided on the hot runner 303, and the gating mechanism 304 is movably abutted against the inside of the cavity mold 301.

[0022] It should be noted that the cold runner 302 in the cavity mold 301 described in this embodiment is located on the outside of the cavity, and the cooling system on the injection mold is connected to the cold runner 302. Furthermore, because the pipette tip body is narrow at the bottom and wide at the top, the cooling rate at the bottom is faster than at the top. Based on multiple experimental records of the pipette tip's condensation time, the downward movement of the gating mechanism 304 and the detachment of the tip are controlled. The flow guiding mechanism 305 is connected to the barrel inside the injection mold used to transport the injection molding liquid raw material. The raw material enters the flow guiding mechanism 305 and then enters the hot runner 303, and is then transported through the gating mechanism 304 to the cavity to cooperate with the core mold 103 for injection molding of the pipette tip.

[0023] The lower module 101 is symmetrically provided on both sides with a molding assembly 20 that drives the flow guiding mechanism 305 to move up and down. The molding assembly 20 includes a driving component 201 and a limiting mechanism 202. The driving component 201 is located on one side of the lower module 101, and the limiting mechanism 202 is located on one side of the lower module 101. The driving component 201 is in contact with the limiting mechanism 202.

[0024] It should be noted that the drive component 201 is a bidirectional hydraulic cylinder, which operates via a control switch and power supply. When the drive component 201 operates, it moves the movable ejector rod, causing it to abut against the limiting mechanism 202. The limiting mechanism 202 is connected to the extension plate 406 on the movable plate 403, which in turn causes the gating mechanism 304 to rise and fall. This allows the injection molded part to detach directly after the tip has solidified, preventing damage to the tip during subsequent demolding.

[0025] In one embodiment of this application, such as Figure 1 and Figure 2 As shown, it also includes a positioning component 40, which includes a fixed template 401 disposed on one side of the cavity mold 301, a movable plate 403 disposed between the fixed template 401 and the cavity mold 301, and a hot runner 303 disposed on the side of the movable plate 403 away from the fixed template 401. A reset component 402 is provided between the fixed template 401 and the movable plate 403, and extension plates 406 are symmetrically disposed on both sides of the movable plate 403 along the X-axis.

[0026] It should be noted that the positioning component 40 described in this embodiment is installed inside the lower module 101, the fixed template 401 is fixedly installed at the bottom of the cavity mold 301, and there is a gap between the fixed template 401 and the cavity mold 301. The movable plate 403 is movably installed in the gap. The reset component 402 is a reset spring. The two ends of the reset component 402 are respectively connected to the movable plate 403 and the fixed template 401. The pouring mechanism 304 is automatically reset through the reset component 402.

[0027] Furthermore, in order to ensure that the gating mechanism 304 and the cavity mold 301 fit tightly together during the spring pushing process, the overall elastic performance of the reset component 402 needs to be set according to actual needs to ensure that no liquid raw material overflows during the injection molding process.

[0028] In one embodiment of this application, such as Figure 2 and Figure 3 As shown, the pouring mechanism 304 includes a main pouring pipe 3041, a stop block 3042, and an overflow prevention part 3043.

[0029] The main gating pipe 3041 is installed on the hot runner 303, the baffle 3042 is installed on the main gating pipe 3041, and the overflow prevention part 3043 is installed at the bottom of the cavity mold 301, and the overflow prevention part 3043 and the main gating pipe 3041 are in contact connection.

[0030] It should be noted that the main gating pipe 3041 and the hot runner 303 are integrally formed and interconnected. The stop block 3042 is an annular stop block with a limiting groove on the inner side of the bottom wall of the cavity mold 301. When the stop block 3042 moves, it will engage in the limiting groove. The movement of the stop block 3042 limits the movement and enhances the overall sealing to prevent raw material from dripping.

[0031] In one embodiment of this application, such as Figure 2 and Figure 5 As shown, the flow guiding mechanism 305 includes an external movable flow guiding pipe 3051, an internal fixed flow guiding pipe 3052, and a scraper collar 3053.

[0032] The inner fixed guide tube 3052 is installed inside the cavity mold 301, the outer movable guide tube 3051 is movably sleeved outside the inner fixed guide tube 3052, and the scraper collar 3053 is installed inside the outer movable guide tube 3051 and sleeved outside the inner fixed guide tube 3052.

[0033] It should be noted that the inner fixed guide tube 3052 is fixedly installed. The injection molding liquid raw material is transported through the inner fixed guide tube 3052 and enters the outer movable guide tube 3051. The outer movable guide tube 3051 and the hot runner 303 are interconnected. Therefore, when the hot runner 303 moves with the movable plate 403, the outer movable guide tube 3051 moves synchronously. The scraper collar 3053 then moves on the surface of the inner fixed guide tube 3052, preventing backflow of the raw material and scraping off the raw material adhering to the surface of the inner fixed guide tube 3052.

[0034] Furthermore, the inner fixed guide tube 3052, the outer movable guide tube 3051, and the scraper collar 3053 are made of the same material, which is heat-resistant and has a high melting point, unaffected by the liquid injection molding material. The scraper collar 3053 and the inner fixed guide tube 3052 are connected by a transition fit, thereby preventing the injection molding material from flowing back while ensuring the scraper collar 3053 moves.

[0035] In one embodiment of this application, such as Figure 1 As shown, the limiting mechanism 202 includes an outer fixed frame 2021 and an inner limiting block 2022.

[0036] The outer fixing frame 2021 is located on one side of the extension plate 406, and the inner limiting block 2022 is located inside the outer fixing frame 2021.

[0037] It should be noted that a slot is provided on the lower module 101 for the extension plate 406 to extend out. The outer fixing frame 2021 is installed at the bottom of the extension plate 406. The outer fixing frame 2021 is a hollow frame, and the inner limiting block 2022 is installed inside the outer fixing frame 2021.

[0038] In one embodiment of this application, such as Figure 1 As shown, the output end of the drive component 201 is connected to the movable push rod, and the movable push rod and the inner limit block 2022 are in contact connection. The inner limit block 2022 and the movable push rod are respectively provided with matching inclined end faces.

[0039] One embodiment is as follows: the tilt angle of the inner limiting block 2022 is as follows Figure 1 As shown, when the inner limit block 2022 and the movable top rod cooperate, the movable plate 403 will move downward as the drive component 201 runs.

[0040] Another embodiment is as follows: the inclination angle of the inner limit block 2022 is symmetrically arranged within the outer fixed frame 2021 along the horizontal direction. When the driving component 201 is running, the movable push rod abuts against the inner limit block 2022 during its movement, pushing the movable plate 403 upward. At this time, the function of the reset component 402 is to drive the movable plate 403 downward to reset.

[0041] Furthermore, based on the time required for injection molding, a time relay is added to the injection molding equipment to cycle the drive component 201 in a timely manner, so as to ensure that the drive component 201 is operated in a timely manner within the time required from mold closing to demolding.

[0042] In one embodiment of this application, such as Figure 2 As shown, a positioning rod 404 is provided on the side of the fixed template 401 near the movable plate 403. One side of the positioning rod 404 is connected to the cavity mold 301. A positioning pin 405 is provided on the side of the movable plate 403 away from the fixed template 401. The positioning pin 405 is movably inserted into the cavity mold 301.

[0043] It should be noted that, in this embodiment, the positioning rod 404 passes through the movable plate 403, and the movable plate 403 is provided with a through hole that matches the positioning rod 404. The positioning pin 405 is inserted into the cavity mold 301, and the cavity mold 301 is provided with a positioning hole, so that the movable plate 403 is limited to rise and fall when it moves.

[0044] In one embodiment of this application, such as Figure 3 and Figure 4 As shown, the outer side of the top wall port of the main pouring pipe 3041 is provided with an inwardly inclined end face 3044, and the bottom wall of the overflow prevention part 3043 is seamlessly attached to the inwardly inclined end face 3044.

[0045] It should be noted that the top wall of the main gating pipe 3041 has an inwardly inclined end face, and the overflow prevention part 3043 is seamlessly attached to the top wall of the main gating pipe 3041. Conversely, the bottom wall of the overflow prevention part 3043 has a corresponding inclined end face. The inclined end face design and seamless attachment ensure prevention of overflow and guarantee the quality of the molded part during the injection molding process.

[0046] Furthermore, the inner inclined end face 3044 is formed by the downward inward slope of the outer side of the top wall of the main gating pipe 3041, and the inclination angle is set according to the actual injection molding requirements. Similarly, the bottom wall of the anti-overflow part 3043 is provided with an outer inclined end face that slopes upward from the inner side of the bottom wall to the outer side.

[0047] Specifically, the operation steps of the pipette tip injection molding mold are as follows: the upper mold assembly 102 and the lower mold assembly 101 are closed by the injection molding equipment, and the injection material is transported into the inner fixed guide tube 3052. The injection material is then transported into the outer movable guide tube 3051 and the hot runner 303. At this time, the movable plate 403 moves upward so that the gating mechanism 304 fits together seamlessly, and the injection material is transported into the cavity mold 301. The injection material is then injection molded into the pipette tip according to the core template 103.

[0048] In the sprue mechanism 304, the main sprue 3041 moves upward and is limited by the stop block 3042, while the anti-overflow part 3043 and the inner inclined end face 3044 fit together seamlessly, ensuring pressure while delivering raw materials into the mold cavity 301. During the molding process of the pipette tip, the cooling system and cold runner 302 in the injection molding equipment are connected to cool the injection molded part. When the tip of the injection molded part solidifies, the running drive component 201 drives the movable ejector rod to move. The movable ejector rod moves and cooperates with the inner limit block 2022, causing the movable plate 403 to move downward and disengage the main sprue 3041 and the anti-overflow part 3043. At this time, the tip is in a state of just solidification, thereby preventing the tip of the pipette tip from deforming or breaking due to the overall solidification time being too long during demolding.

[0049] In summary, the injection molding mold based on the pipette tip in this application adopts a movable gating mechanism in the lower mold assembly. The seamless fit of the gating mechanism ensures the feeding pressure while preventing material overflow. The rapid separation during molding ensures that the tip is free from deformation and damage, effectively guaranteeing the overall quality of the molded part.

[0050] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An injection molding die based on a pipette tip, comprising a molding die (10), said molding die (10) comprising a lower die assembly (101) and an upper die assembly (102), characterized in that, The lower mold (101) is provided with a cavity injection molding assembly (30) for injection molding. The cavity injection molding assembly (30) includes a cavity mold (301). The cavity mold (301) is provided with a cold runner (302) for accelerating the cooling and molding of the molded part. The cavity mold (301) is also provided with a flow guiding mechanism (305). A hot runner (303) is provided on one side of the flow guiding mechanism (305). A gating mechanism (304) is provided on the hot runner (303), and the gating mechanism (304) is movably abutting against the inside of the cavity mold (301). The lower module (101) is symmetrically provided on both sides with a molding assembly (20) that drives the flow guiding mechanism (305) to move up and down. The molding assembly (20) includes a driving component (201) and a limiting mechanism (202). The drive component (201) is disposed on one side of the lower module (101); The limiting mechanism (202) is disposed on one side of the lower module (101), and the driving component (201) abuts against the limiting mechanism (202).

2. The injection molding die based on a pipette tip according to claim 1, characterized in that, It also includes a positioning component (40), which includes a fixed template (401) disposed on one side of the cavity mold (301), a movable plate (403) disposed between the fixed template (401) and the cavity mold (301), and the hot runner (303) disposed on the side of the movable plate (403) away from the fixed template (401), a reset component (402) disposed between the fixed template (401) and the movable plate (403), and extension plates (406) symmetrically disposed on both sides of the movable plate (403) along the X-axis.

3. The injection molding die based on a pipette tip according to claim 1, characterized in that, The gating mechanism (304) includes a main gating pipe (3041), a stop block (3042), and an overflow prevention part (3043), wherein, The main gating pipe (3041) is disposed on the hot runner (303); The stop block (3042) is disposed on the main pouring pipe (3041); The overflow prevention part (3043) is provided at the bottom end of the cavity mold (301), and the overflow prevention part (3043) and the main gating pipe (3041) are in contact connection.

4. The injection molding mold based on a pipette tip according to claim 1, characterized in that, The flow guiding mechanism (305) includes an outer movable flow guiding pipe (3051), an inner fixed flow guiding pipe (3052), and a scraper collar (3053), wherein, The internal fixed guide tube (3052) is disposed inside the cavity mold (301); The external movable guide tube (3051) is movably sleeved outside the internal fixed guide tube (3052); The scraper collar (3053) is disposed inside the outer movable guide tube (3051), and the scraper collar (3053) is sleeved outside the inner fixed guide tube (3052).

5. The injection molding die based on a pipette tip according to claim 2, characterized in that, The limiting mechanism (202) includes an outer fixing frame (2021) and an inner limiting block (2022), wherein, The external fixing frame (2021) is disposed on one side of the extension plate (406); The inner limiting block (2022) is disposed within the outer fixing frame (2021).

6. The injection molding die based on a pipette tip according to claim 5, characterized in that, The output end of the drive component (201) is connected to the movable push rod, and the movable push rod and the inner limit block (2022) are in abutting connection. The inner limit block (2022) and the movable push rod are respectively provided with matching inclined end faces on their opposite end faces.

7. The injection molding die based on a pipette tip according to claim 2, characterized in that, The fixed template (401) is provided with a positioning rod (404) on the side near the movable plate (403), and one side of the positioning rod (404) is connected to the cavity mold (301). The movable plate (403) is provided with a positioning pin (405) on the side opposite to the fixed template (401), and the positioning pin (405) is movably inserted into the cavity mold (301).

8. The injection molding die based on a pipette tip according to claim 3, characterized in that, The main pouring pipe (3041) has an inwardly inclined end face (3044) on the outer side of its top wall port, and the bottom wall of the anti-overflow part (3043) is seamlessly attached to the inwardly inclined end face (3044).

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