Injection mold structure with multiple cavities and non-uniform glue positions for small products made of PP (polypropylene) materials

Abstract

The utility model belongs to the technical field of injection molds, and particularly discloses a multi-cavity and non-uniform-glue-position PP material small product injection mold structure which comprises a shell and a pressing plate, the pressing plate is arranged above the shell, a hanging bracket is installed between the front portion and the rear portion of the top end of the shell, and air cylinders are installed on the two sides of the interior of the hanging bracket respectively. A top die is fixed to the bottom of the pressing plate, and a feeding pipe is longitudinally installed in the center of the interior of the pressing plate. According to the multi-cavity and non-uniform-glue-position PP material small product injection mold structure, a first discharging hole is formed between the side face of a three-way pipe and a top mold, a second discharging hole is formed between the bottom of a lower three-way pipe and the top mold, a hot melt plastic liquid conveying pipeline is fixedly connected with a feeding pipe, and after a material pump is started, thermoplastic liquid is injected into the upper three-way pipe; and then the materials flow into the two groups of lower three-way pipes under the control of the valves on the two sides, and are guided out from the discharge hole I in the side surface and the discharge hole II in the bottom, so that the problem of non-uniform injection molding is solved.

Description

Technical Field

[0001] This utility model relates to the field of injection mold technology, specifically to the structure of a small PP material injection mold with multiple cavities and uneven glue distribution. Background Technology

[0002] Polypropylene (PP) is widely used in injection molding due to its good chemical stability, high temperature resistance, and impact resistance. Multi-cavity injection molding technology is often used for molding multiple small products. However, when the multiple injection holes (glue sites) are uneven, defects such as incomplete filling and air bubble formation frequently occur. Particularly in the injection molding of small products with multiple cavities and uneven glue distribution, inconsistent injection pressure and flow rate often lead to uneven material filling in each cavity, resulting in poor product quality, such as air bubbles, shrinkage, warping, or incomplete filling in certain areas. Therefore, optimizing the mold structure to ensure uniform filling of each cavity during injection molding and improve the molding quality of small products has become a current technical challenge.

[0003] Now, a novel injection mold structure for small PP products with multiple cavities and uneven glue distribution is proposed to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide a multi-cavity injection mold structure for small PP products with uneven glue distribution, so as to solve the problem of uneven injection mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a multi-cavity injection mold structure for small PP products with uneven glue distribution, comprising a shell and a pressure plate. The pressure plate is disposed on the top of the shell. A hanger is installed between the front and rear ends of the top of the shell, and cylinders are respectively installed on both sides inside the hanger. A top mold is fixed to the bottom of the pressure plate. A feed pipe is longitudinally installed at the center of the inside of the pressure plate, and a material pump is installed on the feed pipe. An upper tee pipe is installed at the top of the center of the inside of the top mold, and a valve is installed in the upper tee pipe. Lower tee pipes are respectively fixed to both sides of the bottom of the upper tee pipe, and a discharge hole one is provided between the side of the lower tee pipe and the top mold. A discharge hole two is provided between the bottom of the lower tee pipe and the top mold. Insulation cotton blocks are fixedly installed inside the top mold. A groove is provided inside the shell, and a bottom mold is installed at the bottom end of the groove.

[0006] As a further technical solution of this utility model, the heat insulation cotton block is wrapped around the outside of the upper tee pipe and the lower tee pipe, and the bottom of the feed pipe is connected to the upper tee pipe.

[0007] As a further technical solution of this utility model, the curvature of the lower surface of the top mold matches the inner wall of the bottom mold, and the bottom of the piston rod of the cylinder is fixedly connected to the pressure plate.

[0008] As a further technical solution of this utility model, a drainage chamber is fixed between the two sides of the inner wall of the bottom mold. A liquid inlet pipe is installed between the right side of the drainage chamber and the bottom mold, and a right liquid pump is installed on the liquid inlet pipe. A liquid outlet pipe is installed between the left side of the drainage chamber and the bottom mold, and a left liquid pump is installed on the liquid outlet pipe. A blower is installed on the outer side of the center of the rear of the outer shell. A coil is installed at the center of the interior of the rear of the outer shell, and an air duct is fixed between the front end of the coil and the bottom mold. An air hole is provided between the front and rear of the interior of the bottom mold. A mold cavity is provided inside the bottom mold. A slot is provided inside the front end of the outer shell.

[0009] As a further technical solution of this utility model, the rear of the air hole is fixedly connected to the air duct, and the air outlet of the blower is fixedly connected to the coil.

[0010] As a further technical solution of this utility model, the inlet pipe and the outlet pipe are symmetrically installed on both sides of the drainage chamber, and the curvature of the drainage chamber is the same as that of the mold chamber.

[0011] As a further technical solution of this utility model, three sets of air grooves are respectively provided at the front and rear of the bottom mold, and three sets of air pipes are installed at the rear of the bottom mold, with air valves installed on the air pipes.

[0012] As a further technical solution of this utility model, the front end of the air pipe is connected to the air groove, and the air pipe and the air valve are on the same vertical plane.

[0013] Compared with the prior art, the beneficial effects of this utility model are: the injection mold structure of this multi-cavity and uneven PP material small product not only achieves uniform injection and rapid cooling and shaping, but also avoids the generation of air bubbles;

[0014] (1) By setting a discharge hole one between the side of the three-way pipe and the top mold, and setting a discharge hole two between the bottom of the lower three-way pipe and the top mold, the hot melt plastic liquid conveying pipe is fixedly connected to the feed pipe. After starting the material pump, the hot melt plastic liquid is injected into the upper three-way pipe, and then flows into the two sets of lower three-way pipes under the control of the valves on both sides. The material is discharged from the discharge hole one on the side and the discharge hole two at the bottom. At this time, the hot melt plastic liquid fills the mold cavity between the top mold and the bottom mold. The top mold is also equipped with heat insulation cotton blocks to prevent the temperature from dropping and causing the hot melt plastic liquid to block the pipe. According to the different structural characteristics of multiple injection holes (discharge hole one, discharge hole two), the diameter, length and shape of the flow channel are precisely designed to ensure that each hole can receive uniform material flow during the injection process. By reasonably configuring the flow channel, the PP material can flow evenly to all holes, avoiding uneven filling and air bubbles caused by unreasonable flow channel design.

[0015] (2) By fixing a drainage chamber between the two sides of the inner wall of the bottom mold, start the right liquid pump and inject cold water into the drainage chamber in the center through the liquid inlet pipe. The undulation of the drainage chamber is the same as the bottom of the mold cavity, which can perfectly fit the bottom of the mold cavity and quickly cool and solidify the extruded thermoplastic liquid. This structure can be circulated. After the heated cold water is started, it will be discharged from the liquid outlet pipe on the left side. At the same time, the blower is turned on and blows cold air to the multiple air holes of the bottom mold through the air pipe connected by the coil. This ensures that the coolant can flow evenly through the entire mold so that the material can be cooled evenly in the same time, avoiding warping and dimensional instability caused by uneven cooling. Adjust the flow rate and temperature of the coolant according to the needs of different areas to ensure that each product area achieves the best cooling effect in a suitable time, avoiding the problem of excessively long production cycle caused by long-term cooling.

[0016] (3) By setting three sets of air grooves in the rear of the bottom mold, and installing air grooves in the inner walls of the rear and front ends of the mold cavity, the air inlet and outlet structure of the bottom mold can be adjusted by the air valve installed on the air pipe when the thermoplastic liquid is injected, so as to ensure that the gas can be discharged smoothly during the injection process and avoid the generation of bubbles and voids. Especially in the vicinity of deep cavity and small glue position, tiny air holes are set to ensure that the gas can be discharged quickly and prevent surface defects caused by gas retention. Unlike traditional molds, where the number of air holes is insufficient or the position is improper, resulting in gas retention and affecting the molding quality. Attached Figure Description

[0017] Figure 1 This is a frontal cross-sectional view of the present invention.

[0018] Figure 2 This is a front view cross-sectional structural diagram of the top mold of this utility model;

[0019] Figure 3 This is a front view cross-sectional structural diagram of the outer shell of this utility model;

[0020] Figure 4 This is a side view cross-sectional structural diagram of the outer shell of this utility model.

[0021] In the diagram: 1. Outer shell; 2. Pressure plate; 3. Hanger; 4. Cylinder; 5. Material pump; 6. Feed pipe; 7. Top mold; 8. Groove; 9. Bottom mold; 10. Mold chamber; 11. Air hole; 12. Drainage chamber; 13. Air groove; 14. Discharge hole one; 15. Insulation cotton block; 16. Discharge hole two; 17. Lower tee pipe; 18. Valve; 19. Upper tee pipe; 20. Air valve; 21. Right liquid pump; 22. Liquid inlet pipe; 23. Liquid outlet pipe; 24. Left liquid pump; 25. Groove; 26. Air duct; 27. Coil; 28. Blower; 29. ​​Air pipe. Detailed Implementation

[0022] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0023] Please see Figure 1-4 This utility model provides an embodiment of a PP material small product injection mold structure with multiple cavities and uneven glue distribution, including a shell 1 and a pressure plate 2. The pressure plate 2 is provided on the top of the shell 1. A hanger 3 is installed between the front and rear of the top of the shell 1. A cylinder 4 is installed on both sides inside the hanger 3. A top mold 7 is fixed at the bottom of the pressure plate 2. A feed pipe 6 is installed longitudinally at the center inside the pressure plate 2. A material pump 5 is installed on the feed pipe 6. An upper tee pipe 19 is installed at the top of the center inside the top mold 7. A valve 18 is installed in the upper tee pipe 19. Lower tee pipes 17 are fixed on both sides at the bottom of the upper tee pipe 19. A discharge hole 14 is provided between the side of the lower tee pipe 17 and the top mold 7. A discharge hole 2 16 is provided between the bottom of the lower tee pipe 17 and the top mold 7. A heat insulation cotton block 15 is fixedly installed inside the top mold 7. A groove 8 is provided inside the shell 1. A bottom mold 9 is installed at the bottom of the groove 8.

[0024] The insulation cotton block 15 is wrapped around the outside of the upper tee pipe 19 and the lower tee pipe 17. The bottom of the feed pipe 6 is connected to the upper tee pipe 19. The curvature of the lower surface of the top mold 7 matches the inner wall of the bottom mold 9. The bottom of the piston rod of the cylinder 4 is fixedly connected to the pressure plate 2.

[0025] Specifically, such as Figure 1 and Figure 2 As shown, the hot melt plastic liquid conveying pipe is fixedly connected to the feed pipe 6. After the material pump 5 is started, the hot melt plastic liquid is injected into the upward tee pipe 19. Then, under the control of the valves 18 on both sides, it flows into the two sets of downward tee pipes 17 and is discharged from the side discharge hole 14 and the bottom discharge hole 2 16. At this time, the hot melt plastic liquid fills the mold cavity 10 between the top mold 7 and the bottom mold 9. The top mold 7 is also equipped with heat insulation cotton blocks 15 to prevent the temperature from dropping and causing the hot melt plastic liquid to block the pipe.

[0026] A drainage chamber 12 is fixed between the two sides of the inner wall of the bottom mold 9. An inlet pipe 22 is installed between the right side of the drainage chamber 12 and the bottom mold 9, and a right liquid pump 21 is installed on the inlet pipe 22. An outlet pipe 23 is installed between the left side of the drainage chamber 12 and the bottom mold 9, and a left liquid pump 24 is installed on the outlet pipe 23. A blower 28 is installed on the outer side of the center of the rear of the outer shell 1. A coil 27 is installed at the center of the interior of the rear of the outer shell 1, and an air duct 26 is fixed between the front end of the coil 27 and the bottom mold 9. An air hole 11 is provided between the front and rear of the interior of the bottom mold 9. A mold chamber 10 is provided inside the bottom mold 9. A slot 25 is provided inside the front end of the outer shell 1.

[0027] The rear of the air vent 11 is fixedly connected to the air duct 26, the air outlet of the blower 28 is fixedly connected to the coil 27, the liquid inlet pipe 22 and the liquid outlet pipe 23 are symmetrically installed on both sides of the drainage chamber 12, and the curvature of the drainage chamber 12 is the same as that of the mold chamber 10.

[0028] Specifically, such as Figure 1 , Figure 3 and Figure 4 As shown, the right liquid pump 21 is started, and cold water is injected into the central drainage chamber 12 through the liquid inlet pipe 22. The undulation of the drainage chamber 12 is the same as the bottom of the mold chamber 10, which can perfectly fit under the mold chamber 10 and quickly cool and solidify the extruded thermoplastic liquid. This structure can be circulated. After the heated cold water is started, it will be discharged from the left liquid outlet pipe 23 after the left liquid pump 24 is started. At the same time, the blower 28 is turned on and blows cold air to the multiple air holes 11 of the bottom mold 9 through the air pipe 26 connected by the coil 27.

[0029] Three sets of air grooves 13 are provided at the front and rear of the bottom mold 9, and three sets of air pipes 29 are installed at the rear of the bottom mold 9. Air valves 20 are installed on the air pipes 29. The front end of the air pipes 29 is connected to the air grooves 13, and the air pipes 29 and the air valves 20 are on the same vertical plane.

[0030] Specifically, such as Figure 1 and Figure 4 As shown, air grooves 13 are installed in the inner walls of the rear and front ends of the mold cavity 10, respectively. When the thermoplastic liquid is injected, the air inlet and outlet structure of the bottom mold 9 can be adjusted by the air valve 20 installed on the air pipe 29 to ensure that the gas can be discharged smoothly during the injection process and avoid the generation of bubbles and voids. Especially near the deep cavity and small glue position, tiny air holes 11 are set to ensure that the gas can be discharged quickly and prevent surface defects caused by gas retention.

[0031] Working Principle: In use, this invention first connects the hot-melt plastic liquid delivery pipe to the feed pipe 6 via the cylinder 4, the pressure plate 2, and the top mold 7. After starting the material pump 5, the hot-melt plastic liquid is injected into the upward tee pipe 19. Then, under the control of the valves 18 on both sides, it flows into two sets of downward tee pipes 17, exiting through the side discharge hole 14 and the bottom discharge hole 16. At this time, the hot-melt plastic liquid fills the mold cavity 10 between the top mold 7 and the bottom mold 9. The top mold 7 is also equipped with insulation cotton blocks 15 to prevent the hot-melt plastic liquid from clogging the pipes due to temperature drop. Air grooves 13 are installed on the inner walls of the rear and front ends of the mold cavity 10. During hot-melt plastic liquid injection, the air inlet and outlet structure of the bottom mold 9 can be adjusted via the air valve 20 installed on the air pipe 29 to ensure that gas can be smoothly discharged during the injection process, avoiding air bubbles and voids. The process begins with the right liquid pump 21 being activated, injecting cold water into the central drainage chamber 12 through the inlet pipe 22. The undulations of the drainage chamber 12 are the same as the bottom of the mold chamber 10, allowing it to perfectly fit under the mold chamber 10 and rapidly cool and solidify the extruded thermoplastic liquid. This structure can circulate. The heated cold water will be discharged from the left outlet pipe 23 after the left liquid pump 24 is activated. Simultaneously, the blower 28 is turned on, and cold air is blown through the air pipe 26 connected to the coil 27 to the multiple air holes 11 of the bottom mold 9, ensuring that the coolant can flow evenly through the entire mold so that the material can be cooled evenly in the same amount of time. The cylinder 4, material pump 5, right liquid pump 21, left liquid pump 24, and blower 28 mentioned in this case are all controlled by a mature control system, which is existing technology, so the principle 5 will not be elaborated.

[0032] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A small PP material injection mold structure with multiple cavities and uneven glue distribution, comprising a shell (1) and a pressure plate (2), characterized in that: A pressure plate (2) is provided above the outer shell (1). A hanger (3) is installed between the front and rear ends of the top of the outer shell (1). Cylinders (4) are installed on both sides inside the hanger (3). A top mold (7) is fixed at the bottom of the pressure plate (2). A feed pipe (6) is installed longitudinally at the center inside the pressure plate (2). A material pump (5) is installed on the feed pipe (6). An upper tee pipe (19) is installed at the top center inside the top mold (7). A material pump (5) is installed in the upper tee pipe (19). There is a valve (18), and the bottom sides of the upper three-way pipe (19) are respectively fixed with lower three-way pipes (17), and the side of the lower three-way pipe (17) and the top mold (7) are provided with a discharge hole one (14), the bottom of the lower three-way pipe (17) and the top mold (7) are provided with a discharge hole two (16), the top mold (7) is fixedly installed with a heat insulation cotton block (15), the shell (1) is provided with a groove (8), and the bottom end of the groove (8) is installed with a bottom mold (9).

2. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 1, characterized in that: The insulation cotton block (15) is wrapped around the outside of the upper tee pipe (19) and the lower tee pipe (17), and the bottom of the feed pipe (6) is connected to the upper tee pipe (19).

3. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 1, characterized in that: The curvature of the lower surface of the top mold (7) matches the inner wall of the bottom mold (9), and the bottom of the piston rod of the cylinder (4) is fixedly connected to the pressure plate (2).

4. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 1, characterized in that: A drainage chamber (12) is fixed between the two sides of the inner wall of the bottom mold (9). An inlet pipe (22) is installed between the right side of the drainage chamber (12) and the bottom mold (9), and a right liquid pump (21) is installed on the inlet pipe (22). An outlet pipe (23) is installed between the left side of the drainage chamber (12) and the bottom mold (9), and a left liquid pump (24) is installed on the outlet pipe (23). A blower (28) is installed on the outer side of the rear center of the outer shell (1). A coil (27) is installed at the center of the rear interior of the outer shell (1), and an air duct (26) is fixed between the front end of the coil (27) and the bottom mold (9). An air hole (11) is provided between the front and rear of the bottom mold (9). A mold chamber (10) is provided inside the bottom mold (9). A slot (25) is provided inside the front end of the outer shell (1).

5. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 4, characterized in that: The rear of the air vent (11) is fixedly connected to the air duct (26), and the air outlet of the blower (28) is fixedly connected to the coil (27).

6. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 4, characterized in that: The inlet pipe (22) and outlet pipe (23) are symmetrically installed on both sides of the drainage chamber (12), and the curvature of the drainage chamber (12) is the same as that of the mold chamber (10).

7. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 1, characterized in that: Three sets of air grooves (13) are respectively provided in the front and rear of the bottom mold (9), and three sets of air pipes (29) are installed in the rear of the bottom mold (9), and air valves (20) are installed on the air pipes (29).

8. The injection mold structure for small PP products with multiple cavities and uneven glue distribution according to claim 7, characterized in that: The front end of the air pipe (29) is connected to the air groove (13), and the air pipe (29) and the air valve (20) are on the same vertical plane.

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