Hot runner system capable of reducing weld lines
By employing manifolds, floating plates, and heating elements in the hot runner system, combined with real-time temperature monitoring by thermocouples and control of valve needle movement, the problem of weld lines in injection molding is solved, improving the structural strength and lifespan of the product.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-17
- Publication Date
- 2026-04-10
AI Technical Summary
The formation of weld lines during injection molding reduces the structural strength and lifespan of the product, and existing technologies are unable to effectively reduce the occurrence of weld lines.
It adopts a design of manifold and floating plate, combined with heating elements and thermocouples to monitor the temperature in real time. The cylinder controls the valve needle to make the heating nozzle fill the glue simultaneously, and heating at the corner to ensure that the melt temperature is consistent. Multiple heating nozzles and valve needles are used to injection mold regular plastic parts.
It effectively reduces the formation of weld lines, improves the structural strength and lifespan of products, ensures uniform melt temperature and consistent flow rate, and enhances injection molding quality.
Smart Images
Figure CN224103422U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to injection molding hot nozzle assembly, hot runner technical field, concretely is a hot runner system of reducing weld line. BACKGROUND
[0002] Hot nozzle assembly injection molding as the core technology of plastic product production, its efficiency and quality directly affect production cost and product competitiveness, all want to carry out heating before injecting the cavity, thereby control molten state plastic injection cavity, thereby realize continuous stable injection molding.
[0003] Injection molding will appear weld line, it is a common defect in the injection molding process, mainly due to the flow of plastic melt in the mold cavity, two or more melt flow front meet after not completely fused and form linear marks.
[0004] When meeting, melt temperature, pressure is insufficient or flow rate is inconsistent, cannot completely fuse, form weld line;Unreasonable runner design (such as each branch runner length, cross section is inconsistent), leading to melt to reach different time of different regions, the melt temperature of first arrival reduces, and the melt of later arrival is not fully fused when merging;Poor flowability of plastic material (such as high viscosity material), too low molding temperature, injection speed is too slow, will make melt viscosity increase when merging, difficult to fuse.
[0005] Weld line is difficult to avoid in traditional injection molding, only can reduce, therefore the utility model discloses a hot runner system of reducing weld line. UTILITY MODEL CONTENT
[0006] To solve the above technical problems, according to one aspect of the utility model, the utility model provides the following technical scheme:
[0007] A hot runner system of reducing weld line, including the shunt plate, the shunt plate is equipped with main hot nozzle, and a plurality of branch hot nozzles are connected with the runner of main hot nozzle;It also includes a cavity, the cavity has a plurality of straight edges, the adjacent straight edge has a corner between, the gate of a plurality of branch hot nozzles is distributed at the center of a plurality of straight edges, and a plurality of branch hot nozzles simultaneously fill glue liquid at the center of a plurality of straight edges.
[0008] A further technical scheme of the hot runner system of reducing weld line, the thickness of the center of the corner is H1, the thickness of the straight edge is H2, and H1 is greater than H2.
[0009] A further technical scheme of the hot runner system of reducing weld line, a plurality of corners are each equipped with a heating element.
[0010] A further technical solution of the hot runner system for reducing the weld line, the heating element comprises heating wires, which are respectively located at the inner side and the outer side of the corner.
[0011] A further technical solution of the hot runner system for reducing the weld line, the fixed mold is connected with thermocouples, which respectively monitor the temperature of each corner in real time.
[0012] A further technical solution of the hot runner system for reducing the weld line, comprising a floating plate, a plurality of valve needles are arranged on the floating plate, and the plurality of valve needles are arranged on the same central axis of a plurality of hot nozzles, a cylinder is arranged on the floating plate, and the cylinder drives the floating plate to move the valve needles up and down.
[0013] A further technical solution of the hot runner system for reducing the weld line, a guide column is arranged on the cylinder.
[0014] The utility model discloses a kind of hot runner systems for reducing the weld line, object is the plastic piece cube, cuboid structure of overall structure rule, injection molding uses a plurality of hot nozzles cooperate with a plurality of valve needles simultaneously injection molding, valve needle is controlled by cylinder to make gate simultaneously fill glue solution;Corner heating heating wire, heating wire is threaded into fixed mold, bypasses corner, cooperate thermocouple, thermocouple is respectively monitored each corner point temperature in real time, guarantee the accuracy of temperature. BRIEF DESCRIPTION OF DRAWINGS
[0015] Figure 1 It is the structure schematic diagram of the utility model;
[0016] Figure 2 It is the structure top view of a specific embodiment of corner cooperation heating element;
[0017] Figure 3 It is the structure side view of a specific embodiment of corner cooperation heating element. DETAILED DESCRIPTION
[0018] To make the purpose, technical scheme and advantage of the utility model more clear, the following will be combined with the drawings to the embodiment of the utility model further detailed description.
[0019] The utility model discloses a kind of hot runner systems for reducing the weld line, please refer to Figures 1-3 , purpose is to reduce the trace of weld line, because weld line can reduce the structural firmness and life of product, and the utility model discloses is the plastic piece of overall structure rule, such as cube cuboid etc., with cube as object, reference Figure 1 、 Figure 2 , with 4 corners and equal straight side, for such plastic piece, its mold reference Figure 1The plastic part uses the cavity 3 of the mold, and the injection of the plastic part uses multiple hot nozzles and multiple valve needles to simultaneously inject. The valve needles are controlled by the cylinder 8 to simultaneously fill the glue liquid in the gate 21. Thus, the welding lines are 4, which are located on the four corners. The reason is that the thickness of the center of the corner 32 is greater than the thickness of the straight edge 31, and the strength of the center of the corner 32 is greater than the strength of the straight edge 31.
[0020] According to a specific embodiment, with reference to Figure 1 、 Figure 2 and Figure 3 , the cavity 3 is defined by the fixed mold 10 and the movable mold 20. The cavity 3 has a plurality of straight edges 31, and the adjacent straight edges 31 have corners 32. The fixed mold 10 is on the top, and the movable mold 20 is on the bottom. The fixed mold 10 and the movable mold 20 are concave-convex matched. The mold further includes a flow distribution plate 5 above the fixed mold 10. The flow distribution plate 5 is provided with a main hot nozzle 1 and a plurality of sub-hot nozzles 2 connected with the flow channel of the main hot nozzle 1. The sub-hot nozzles 2 are partially located in the fixed mold 10 and partially located on the flow distribution plate 5. Taking a cube as an object, the number of straight edges 31 and corners 32 is 4.
[0021] The gates 21 of the plurality of sub-hot nozzles 2 are respectively distributed at the centers 33 of the plurality of straight edges 31. The plurality of sub-hot nozzles 2 simultaneously fill the glue liquid at the centers 33 of the plurality of straight edges 31.
[0022] Taking a cube as an object, the number of sub-hot nozzles 2 is 4, and the number of gates 21 is 4. The gates 21 are respectively distributed directly above the centers 33 of the four straight edges 31. In order to produce the same flow rate of injection, the length and width of the straight edges 31 need to be the same.
[0023] In a further embodiment, the thickness of the center of the corner 32 is H1, and the thickness of the straight edge 31 is H2. The H1 is greater than the H2, so that the strength of the center of the corner 32 is greater than the strength of the straight edge 31.
[0024] In a further embodiment, in order to make the four sub-hot nozzles 2 simultaneously fill the glue liquid at the centers 33 of the plurality of straight edges 31, the specific structure is that a floating plate 6 is arranged above the flow distribution plate 5 in the mold. The floating plate 6 is provided with a plurality of valve needles 7 located directly above the sub-hot nozzles 2, that is, the plurality of valve needles 7 are located on the same central axis as the plurality of sub-hot nozzles 2. In this embodiment, the number of valve needles 7 is 4.
[0025] The floating plate 6 is provided with a cylinder 8. The cylinder 8 drives the floating plate 6 to move the valve needles 7 to control the opening and closing of the sub-hot nozzles 2. The number of cylinders 8 is 1 or 2.
[0026] Specifically, the cylinder 8 includes a piston 81, the piston 81 is connected with a piston rod 82, the piston rod 82 is connected with the floating plate 6, the floating plate 6 is connected with the four valve needles 7, the cylinder 8 receives the instruction of the control system to start, the piston rod 82 pushes the floating plate 6, the four valve needles 7 can move up and down at the same time, and the four valve needles 7 cooperate with the four hot nozzles 2, the four hot nozzles 2 fill the glue liquid at the center 33 of the four straight edges 31 at the same time, and thus the welding line is generated at the center of the corner 32 or the position close to the center.
[0027] The floating plate 6 is provided with a guide column 9, so that the four valve needles 7 cooperate with the four hot nozzles 2 accurately.
[0028] The working process of the cylinder 8 driving the needle valve type hot nozzle is as follows:
[0029] Initial state: the valve needle 7 closes the gate 21 under the action of the cylinder 8, so as to prevent the melt from flowing.
[0030] Injection stage: when the injection machine injects, the control system triggers the electromagnetic valve (not shown in the figure) of the corresponding nozzle, the cylinder 8 pushes the valve needle 7 to retreat, and opens the gate 21.
[0031] The melt flows into the cavity 3 through the hot nozzle runner, and the temperature of the flow front is maintained in the material processing window by the control system.
[0032] The heating element 4 heats the corner 32, so as to reduce the welding line generated by the melt in the runner.
[0033] Mold opening and resetting: the mold is opened, the product is demolded, and the four valve needles 7 are reset under the action of the cylinder 8, to prepare for the next cycle.
[0034] Temperature is crucial to the generation of the welding line, and a large welding line will be generated if there is a temperature difference between the front ends of the two glue liquids, so independent temperature control zones are added at key positions such as the distributor plate 5, the main hot nozzle 1 and the hot nozzle 2, the temperature of each point is monitored in real time by the thermocouple, and the signal is connected with the PLC control system.
[0035] In some specific embodiments, reference is made to Figure 2 , 3 The heating element 4 includes a heating wire 41, the heating wire 41 penetrates into the fixed mold 10, passes around the corner 32, and then penetrates out of the fixed mold 10, the two ends penetrating into and out of the fixed mold 10 are respectively connected with the positive and negative electrodes of the heating power supply, the heating power supply is connected with the thermocouple 30, the thermocouple 30 is four and respectively monitors the temperature of each corner 32 in real time, and is connected with the PLC control system to ensure the accuracy of the temperature.
[0036] In a further specific embodiment, in order to achieve the temperature control effect, the heating wire 41 needs to pass around the corner 32, and pass around the inner side 321 and the outer side 322 of the corner 32 respectively.
[0037] In a further specific embodiment, the fixed mold 10 and the movable mold 20 cooperate to form the cavity 3, and in the height direction, the highest section of the movable mold 20 is lower than the highest section of the fixed mold 10, the thermocouple 30 probe is installed through the fixed mold 10 and the main body is located above the movable mold 20.
[0038] The utility model discloses still a kind of hot runner system for reducing welding line, disclose is the whole structure rule plastic piece, with cube as object, injection molding is simultaneously injection molded with 4 hot nozzle cooperation 4 valve needle, valve needle is controlled by cylinder 8 to make gate 21 simultaneously fill glue liquid;The heating wire 41 heated to corner 32, the heating wire 41 is threaded into fixed mold 10, passes around corner 32, then is threaded out from fixed mold 10, cooperates and connects thermocouple 30, and thermocouple 30 is 4 respectively each real-time monitoring each corner 32 point temperature, guarantee the accuracy of temperature.
[0039] Although the utility model has been described above with reference to the embodiments, various improvements can be made and the components therein can be replaced with equivalents without departing from the scope of the utility model. In particular, as long as there is no structural conflict, each feature in the disclosed embodiments of the utility model can be combined with each other in any way, and the combinations are not exhaustively described in the specification only for the consideration of omitting length and saving resources. Therefore, the utility model is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A hot runner system for reducing weld lines, characterized by, The application relates to a mold for manufacturing a flow distribution plate, which comprises a flow distribution plate provided with a main hot nozzle and a plurality of branch hot nozzles connected with the flow channel of the main hot nozzle; and a cavity, which has a plurality of straight edges and a plurality of corners between adjacent straight edges, and the sprue of the plurality of branch hot nozzles is respectively arranged at the center of the plurality of straight edges, and the plurality of branch hot nozzles simultaneously fill glue liquid at the center of the plurality of straight edges.
2. A hot runner system with reduced weld line according to claim 1, wherein, The thickness of the center of the corner is H1, the thickness of the straight edge is H2, and H1 is greater than H2.
3. A hot runner system with reduced weld line according to claim 2, wherein, A heating element is arranged at each corner.
4. A hot runner system with reduced weld line according to claim 3, wherein, The heating element comprises a heating wire arranged at the inner side and the outer side of the corner.
5. A hot runner system with reduced weld line according to claim 1, wherein, The fixed mold is connected with thermocouples, which respectively monitor the temperature at each corner in real time.
6. A hot runner system with reduced weld line according to claim 1 or 2 or 3 or 4 or 5, characterized in that, The floating plate is provided with a plurality of valve needles, the plurality of valve needles are arranged on the same central axis as the plurality of branch hot nozzles, the floating plate is provided with a cylinder, the cylinder drives the floating plate to move the valve needles up and down.
7. A hot runner system with reduced weld line according to claim 6, wherein, A guide column is arranged on the cylinder.