Cold glue prevention hot nozzle core structure

Abstract

The utility model provides an anti-cold glue hot nozzle core structure. The anti-cold glue hot nozzle core structure comprises a hot nozzle body, a hot nozzle heating ring, a valve needle assembly, a valve needle guide block, a hot nozzle core, a hot nozzle powder glue ring and a heat insulation cap, wherein the hot nozzle heating ring is positioned on the inner side of the hot nozzle body; the cooling water inlet is formed in one end of the hot nozzle body; the hot nozzle body comprises an inner-layer core body, an outer-layer shell, a heat insulating layer, a distributed heating system, a temperature feedback system and a conical melt runner; the distributed heating system comprises an embedded micro heating element and an outer-layer high-frequency induction coil; the miniature heating element is divided into at least three sections for independent temperature control along the axial direction; the heat insulation layer is made of aerogel or a nano porous ceramic material; and a nano ceramic heat insulation ring is arranged at the front end of the nozzle core.

Description

[Technical Field]

[0001] This utility model relates to the field of hot runner hot nozzle structure technology, and in particular to a cold-resin hot nozzle core structure that can improve injection molding defects such as cold glue whitening of transparent plastic products and reduce cost losses caused by defective injection molded products. [Background Technology]

[0002] In the injection molding process, the hot runner system's hot nozzle is a key component for molten plastic to enter the mold cavity from the runner. In the existing technology, when the hot nozzle core is working for a long time or when the machine is stopped, the front melt is prone to cooling and solidification (commonly known as "cold glue") due to uneven temperature control, which can cause blockage, product surface defects, or reduced production efficiency.

[0003] Traditional solutions typically use a single heating rod or an external heating coil, but these solutions have the following problems:

[0004] A. The temperature gradient is large, and the front end of the nozzle dissipates heat quickly, making it difficult to maintain a constant temperature.

[0005] B. The heating element is far from the melt channel, resulting in a slow response speed;

[0006] C. Disassembly and cleaning of cold glue are required when the machine is shut down, which increases maintenance costs.

[0007] Therefore, there is an urgent need for a hot nozzle core structure that can actively prevent the formation of cold glue and improve the accuracy of temperature control. [Utility Model Content]

[0008] The problem with the prior art that this application addresses is:

[0009] In existing technologies, when hot nozzle cores are in operation for a long time or when the machine is stopped, uneven temperature control can cause the front melt to cool and solidify (commonly known as "cold glue"), resulting in blockage, product surface defects, or reduced production efficiency.

[0010] The solution to the technical problem of this utility model is:

[0011] A cold-resistant hot nozzle core structure is provided, including a hot nozzle body, a hot nozzle heating coil located inside the hot nozzle body, a valve needle assembly, a valve needle guide block, a hot nozzle core, a hot nozzle powder ring, and a heat insulation cap; it also includes a cooling water inlet located at one end of the hot nozzle body; the hot nozzle body includes an inner core, an outer shell, a heat insulation layer, a distributed heating system, a temperature feedback system, and a conical melt flow channel; the distributed heating system includes an embedded micro heating element and an outer high-frequency induction coil; the micro heating element is divided into at least three independently temperature-controlled segments along the axial direction; the heat insulation layer is an aerogel or a nanoporous ceramic material; and a nano-ceramic heat insulation ring is provided at the front end of the nozzle core.

[0012] Preferably, the valve needle assembly has a stepped shaft structure, a conical sealing head, and a split guide sleeve; the inner wall of the split guide sleeve is provided with a graphite self-lubricating layer with a thickness of 0.05-0.2mm; it also includes a dynamic compensation component, which contains an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1mm, and the radial fine adjustment of the guide sleeve is achieved by melt pressure; the elastic compensation ring is a high-temperature alloy spring with an adjustable preload range of 50-200N; the spiral angle of the spiral guide groove on the inner wall of the ceramic bushing is 15-45°.

[0013] Preferably, the outer surface of the valve needle is plated with a hard chrome structural layer, and the outer surface of the hard chrome structural layer is coated with a heat-resistant and non-stick layer; the outer surface of the hard chrome structural layer is covered with nanopores to form a nanopore surface, and the heat-resistant and non-stick layer is tightly bonded to the nanopore surface of the hard chrome structural layer by an integral injection molding method to form an integral structure.

[0014] The technical effects achieved by this application in solving the technical problem are as follows:

[0015] Compared with the prior art, the present invention provides a cold-resistant hot nozzle core structure that improves injection molding defects such as whitening of cold glue in transparent plastic products and reduces cost losses caused by defective injection molded products. [Image Description]

[0016] Figure 1 This is a three-dimensional structural diagram of a cold-resistant hot nozzle core structure according to the present invention.

[0017] Figure 2 and Figure 3 This is a cross-sectional structural diagram of a cold-resistant hot nozzle core structure according to the present invention. [Detailed Implementation]

[0018] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0019] It should be understood that the specific embodiments described herein are merely for explaining the present invention and are not intended to limit the present invention.

[0020] Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0021] It should be noted that when a component is said to be "fixed" to another component, it can be directly on the other component or it can be in a middle component. When a component is said to be "connected" to another component, it can be directly connected to the other component or it may be in a middle component.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0023] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0024] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0025] Please see Figures 1 to 3 This utility model discloses a hot nozzle core structure 1 with anti-cold adhesive, comprising a hot nozzle body 13, a hot nozzle heating coil located inside the hot nozzle body 13, a valve needle assembly 12, a valve needle guide block, a hot nozzle core, a hot nozzle powder ring, and a heat insulation cap; it also includes a cooling water inlet located at one end of the hot nozzle body; the hot nozzle body 13 includes an inner core, an outer shell, a heat insulation layer, a distributed heating system, a temperature feedback system, and a conical melt flow channel; the distributed heating system includes an embedded micro heating element and an outer high-frequency induction coil; the micro heating element is divided into at least three independently temperature-controlled sections along the axial direction; the heat insulation layer is an aerogel or a nanoporous ceramic material; and a nano-ceramic heat insulation ring is provided at the front end of the nozzle core.

[0026] This application simultaneously includes a hot nozzle body 13, a hot nozzle heating coil located inside the hot nozzle body 13, a valve needle assembly 12, a valve needle guide block, a hot nozzle core, a hot nozzle powder ring, and a heat insulation cap. It also includes a cooling water inlet located at one end of the hot nozzle body. The hot nozzle body 13 includes an inner core, an outer shell, a heat insulation layer, a distributed heating system, a temperature feedback system, and a conical melt flow channel. The distributed heating system includes an embedded micro heating element and an outer high-frequency induction coil. The micro heating element is divided into at least three independent temperature control segments along the axial direction. The heat insulation layer is made of aerogel or nanoporous ceramic material. A nano-ceramic heat insulation ring is provided at the front end of the nozzle core. In practical applications, through multi-layer composite heating, axial segmented temperature control, and front-end nano-heat insulation design, the technical problem of cold glue easily generated in traditional hot nozzles is solved. The use of embedded resistance wire and high-frequency induction composite heating method, combined with the aerogel heat insulation layer, significantly improves temperature uniformity and response speed.

[0027] In some other embodiments, the valve needle assembly 12 has a stepped shaft structure, a conical sealing head, and a split guide sleeve; the inner wall of the split guide sleeve is provided with a graphite self-lubricating layer with a thickness of 0.05-0.2mm; it also includes a dynamic compensation component, which contains an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1mm, and the radial fine adjustment of the guide sleeve is achieved by melt pressure; the elastic compensation ring is a high-temperature alloy spring with an adjustable preload range of 50-200N; the spiral angle of the spiral guide groove on the inner wall of the ceramic bushing is 15-45°.

[0028] The outer surface of the valve needle is plated with a hard chrome structural layer, and the outer surface of the hard chrome structural layer is coated with a heat-resistant and non-stick layer; the outer surface of the hard chrome structural layer is covered with nanopores to form a nanopore surface, and the heat-resistant and non-stick layer is tightly bonded to the nanopore surface of the hard chrome structural layer by an integral injection molding method to form an integral structure.

[0029] A hot runner nozzle consists of a nozzle body, a heating coil, a valve needle, a valve needle guide block, a nozzle core, a sealing ring, and a heat shield cap. The injection molding process involves the injection molding machine injecting molten resin into the product through a manifold and the nozzle. The valve needle closes, and after cooling, the mold opens to remove the product. This patented design features a cold-resin-preventing nozzle core structure. For transparent cosmetic products, conventional nozzle core structures with heat shield caps are prone to defects such as cold-resin whitening. The improved core structure features an extended thin sheet at the front end, combined with a heat shield cap to prevent nozzle temperature loss to the mold core, while maintaining a constant temperature at the nozzle tip. This patented structure improves injection molding defects such as cold-resin whitening in transparent plastic products, reducing cost losses caused by defective injection molding products.

[0030] The anti-cold glue hot nozzle core structure features an extended thin sheet structure at the front end of the nozzle core, coupled with a heat insulation cap to prevent heat loss from the nozzle tip to the mold core. Simultaneously, the temperature at the nozzle tip keeps the plastic at a constant temperature. This patented structure improves injection molding defects such as whitening due to cold glue in transparent plastic products, reducing cost losses caused by defective injection molded products.

[0031] Through multi-layer composite heating and insulation design, the axial temperature uniformity of the nozzle core is achieved, avoiding the solidification of the melt and improving energy utilization.

[0032] Multi-layer composite structure: including an inner core, an outer shell, and an insulation layer between them.

[0033] Distributed heating system:

[0034] The inner core contains embedded micro heating elements, which are independently temperature-controlled in segments along the axial direction.

[0035] A high-frequency induction coil is wound around the surface of the outer shell to achieve rapid heating.

[0036] Temperature feedback system: Thermocouples are installed at the front, middle and rear of the nozzle core to monitor the temperature in real time and feed it back to the controller.

[0037] Anti-cold glue flow channel design: The melt flow channel adopts a tapered tapered structure to reduce the stagnation area; a nano-ceramic heat insulation ring is set at the front end to reduce the heat dissipation rate;

[0038] Control methods:

[0039] The target temperature curve is set according to the melt type, and the heating power of each segment is dynamically adjusted through a PID algorithm.

[0040] When the machine is stopped, activate the "heat preservation mode" to maintain the temperature of the nozzle tip 5-10°C above the melt solidification point;

[0041] High-frequency induction heating is used to compensate for the temperature loss of the outer layer;

[0042] Beneficial effects:

[0043] Axial temperature difference ≤ ±2℃, completely avoiding the formation of cold glue;

[0044] Energy consumption is reduced by 30%, and response time is shortened by 50%;

[0045] Supports quick color changes, reducing material waste;

[0046] Taking PA66 material injection molding as an example:

[0047] The inner core (1) is made of tungsten copper alloy with a diameter of 8mm and has 3 independently temperature-controlled resistance wires (4) embedded inside.

[0048] The insulation layer (3) is an aerogel composite material with a thickness of 0.5 mm;

[0049] The nano-ceramic heat insulation ring (11) has an inner diameter of 2 mm and a thermal conductivity of ≤1 W / (m·K);

[0050] The controller adjusts the frequency of the high-frequency induction coil (5) to 20kHz based on the feedback data from the thermocouple (9) to maintain the front-end temperature at 245±2℃.

[0051] By employing multi-layer composite heating, axial segmented temperature control, and front-end nano-insulation design, the technical challenge of cold adhesive buildup in traditional hot runners has been solved. The use of an embedded resistance wire and high-frequency induction composite heating method, combined with an aerogel insulation layer, significantly improves temperature uniformity and response speed. It is particularly suitable for high-end injection molding applications such as precision electronic connectors and optical lenses.

[0052] Compared with the prior art, the present invention provides a cold-resistant hot nozzle core structure 1, which improves the injection molding defects such as whitening of transparent plastic products due to cold glue, and reduces the cost losses caused by defective injection molded products.

[0053] By simultaneously configuring a hot nozzle body 13, a hot nozzle heating coil located inside the hot nozzle body 13, a valve needle assembly 12, a valve needle guide block, a hot nozzle core, a hot nozzle powder ring, and a heat insulation cap, and also including a cooling water inlet located at one end of the hot nozzle body, the hot nozzle body 13 includes an inner core, an outer shell, a heat insulation layer, a distributed heating system, a temperature feedback system, and a conical melt flow channel. The distributed heating system includes an embedded micro heating element and an outer high-frequency induction coil; the micro heating element is divided into at least three independent temperature control segments along the axial direction; the heat insulation layer is made of aerogel or nanoporous ceramic material; and a nano-ceramic heat insulation ring is provided at the front end of the nozzle core. In practical applications, through multi-layer composite heating, axial segmented temperature control, and front-end nano-heat insulation design, the technical problem of cold glue easily generated in traditional hot nozzles is solved. By adopting a composite heating method of embedded resistance wire and high-frequency induction, combined with an aerogel heat insulation layer, the temperature uniformity and response speed are significantly improved.

[0054] The embodiments of this utility model described above do not constitute a limitation on the scope of protection of this utility model. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the scope of protection of the claims of this utility model.

Claims

1. A cold-resistant hot nozzle core structure, characterized in that: The device includes a hot nozzle body, a hot nozzle heating coil located inside the hot nozzle body, a valve needle assembly, a valve needle guide block, a hot nozzle core, a hot nozzle powder ring, and a heat insulation cap; it also includes a cooling water inlet located at one end of the hot nozzle body; the hot nozzle body includes an inner core, an outer shell, a heat insulation layer, a distributed heating system, a temperature feedback system, and a conical melt flow channel; the distributed heating system includes an embedded micro heating element and an outer high-frequency induction coil; the micro heating element is divided into at least three independently temperature-controlled sections along the axial direction; the heat insulation layer is made of aerogel or nanoporous ceramic material; and a nano-ceramic heat insulation ring is provided at the front end of the nozzle core.

2. The anti-cold adhesive hot nozzle core structure as described in claim 1, characterized in that: The valve needle assembly has a stepped shaft structure, a conical sealing head, and a split guide sleeve; the inner wall of the split guide sleeve is provided with a graphite self-lubricating layer with a thickness of 0.05-0.2mm; it also includes a dynamic compensation component, which contains an elastic compensation ring and a floating gap; the radial width of the floating gap is 0.02-0.1mm, and the radial fine adjustment of the guide sleeve is achieved by melt pressure; the elastic compensation ring is a high-temperature alloy spring with an adjustable preload range of 50-200N; the spiral angle of the spiral guide groove on the inner wall of the ceramic bushing is 15-45°.

3. The anti-cold adhesive hot nozzle core structure as described in claim 1, characterized in that: The outer surface of the valve needle is plated with a hard chrome structural layer, and the outer surface of the hard chrome structural layer is coated with a heat-resistant and non-stick layer; the outer surface of the hard chrome structural layer is covered with nanopores to form a nanopore surface, and the heat-resistant and non-stick layer is tightly bonded to the nanopore surface of the hard chrome structural layer by an integral injection molding method to form an integral structure.

Images