Hot-runner distribution system for polymer melts for filling mold cavities

Abstract

A hot-runner distribution system for polymer melts for filling mold cavities, wherein a plurality of heating tube elements are connected to each other, and are encircled and heated by only one heating wire or tubular heating element.

Description

[0001] 28-08-2025-43502301 -Skin» tPos t-0033 PCT / DE2025 / 000088 Hot runner distribution system for polymer melts, filling mold cavities. Description: The present invention is a hot runner distribution system for polymer melts, for filling mold cavities. In modern polymer processing, hot runner systems are often used, in which the distribution system distributes the polymer melt to several components. The core component is located below the hot runner nozzles. Furthermore, a connection to the injection molding machine is screwed on above the injection nozzle. The polymer melt is fed to the hot runner nozzles via the injection nozzle. From the hot runner nozzles, the melt is fed into the cavities of the injection mold. The mold expands due to heating. For this reason, the hot runner nozzles must be able to move. Hot runner systems must also be precisely designed and installed in the mold to accommodate thermal expansion, especially since the outer mold structure must be cooler so that the molded parts made of polymer can cool sufficiently after the injection process and be demoldable.Processing pressures in polymer injection molding can exceed 1000. A precise surface treatment and clean integration of the hot runner nozzle length are necessary between the hot runner nozzle and the nozzle. Even when changing the polymer with a different melting temperature, leaks or deformation of hot runner components can occur due to different thermal expansion of the hot runner and nozzle. Every hot runner system 28"Ö8-2Q25-4350£301-HäU" iPas t"ÖO34 PCT / DE2025 / 000088 requires energy or no cold gate spider. Hot runner molds are cooled, yet energy is still consumed, and the climate is affected. The regularly large surface area of ​​the hot runner and the contact points with the mold, mentioned above, ensure the sealing of the system. This can have little impact on the energy balance if the energy consumption of hot runner nozzles is high, as most of the energy is used to cool the mold. A significant effort is required in hot runner systems due to the large number of heating points with the necessary cooling capacity.Temperature sensors. Due to the mass of conventional hot runner components, hot runner nozzles and other components become heavy, necessitating complex control technology, which in turn increases the costs and low energy consumption of hot runner systems, especially when temperatures are exactly as originally designed or when polymer decomposition causes the injection pressure to be changed by the operator. Heating and temperature sensors with exceptionally large connector technology can render the entire system unusable due to overmolding and resulting contamination, leading to the system having to be completely replaced. A hot runner distribution system with polymer melts would be desirable for filling mold cavities with multiple hot tube elements, heating, and controlling the components, as well as the energy consumption of known systems. 28-08-2025-43502301~HauP tPos t"0035 PCT / DE2025 / 000088 This task is accomplished with the features of theCharacteristics of the claim, further developments and embodiments of the invention according to the further claims. According to the invention, a hot runner distribution system for polymer melts is used for filling mold cavities, wherein several hot tube elements are connected to each other and wrapped with only one heating wire or tubular heating element. With the proposed system, the aforementioned disadvantages of the prior art are largely avoided. Energy is used for heating the hot runner system. This is achieved by the fact that the polymer melt is distributed across the hot tubes. Essentially, the system consists of several hot tube elements, in particular the hot runner nozzle body and the injection nozzle. It is proposed that several hot tube elements are wrapped around the hot tube elements by a heating wire using suitably designed windings. This creates several heating zones compared to conventional hot runner systems. For hot runner systems with two hot runner nozzles 35, only one heating zone is proposed. For this purpose, only a temperature sensor 47 is required.In hot runner manifold systems with hot runner nozzles 35, heating zones are proposed, wherein two hot runner nozzles 35 are connected with one 37 and injection nozzle 34 with two 37. The system is based on the number of hot runner nozzles 35. In order to be able to wind from one hot tube element 39 to two heating elements 44, double winding is proposed on the hot tube element, wherein the heating wire 44 is located at the branch point opposite both heating wires. The heating wire windings of the hot tube elements 39 can be provided entirely or with sheathing tubes 48 for protection. The sheathing tubes 48 also serve as a pressure plate for the heating wire 44 on the hot tube elements 39 and also as a reflector to direct energy to the hot tube element 39. The sheathing tubes 48 can... Heating wires 44 can be made with fiberglass or metal tubes (tubular heating elements). The use of heating conductors with galvanic thick-film technology is also conceivable. The needle valve nozzle 29 is attached to the mold plate. The hot end can be sealed.30 of the hot runner nozzle 35 Hot runner nozzle 35 also diaphragm cylinders are sealed. The frame elements 40 preferably a closed frame box. This also ensures protection against contact. 49 can be inserted between the hot tube elements and the frame box. This allows the hot tube elements to be separated again from the mold plate 20. At the hot runner nozzle with needle valve 29, heating wire 44 double winding 65 so that the heating wire 44 is returned to the frame element 40 and connected to the connecting cable with terminal 63. The heating wire 44 is supplied with 230V AC. The system is only suitable for needle valve nozzles 29 and diaphragm cylinders, as well as conventional needle actuation systems and hot runner nozzles without needle valves. Since large mold assemblies can be created with the proposed system, this allows for two-component applications with hot runners to and on molds from other molds. This requires rotating the hot runner nozzles and injection nozzle, which is necessary for this system. 28-08-2025-43502301 -MainPost-0037 PCT / DE2025 / 000088 Preferably, the system is designed with novel hot runner nozzles with needle valves, preferably with a novel diaphragm cylinder, which are more complex than standard hot runner nozzles. It is proposed that nozzles on the mold plate, but rather on the contact point 59, hot runner nozzle 35, are heated by a type of cooler in the area of ​​the melt channel. Here, hot runner nozzles 35 have needle shaft seals 22 at contact points on the mold plate for sealing the needle on the needle shaft 3 49 to the diaphragm cylinder. The hot runner nozzle 35 with needle valve is protected by suitable winding of the heating wire 44 in the upper area in the melt channel, ensuring minimal heat transfer to the mold plate and further protected by the needle shaft seal 22. This is especially important when, due to thermal expansion, the hot runner nozzle 35 is still completely attached to the mold plate. The temperature at contact point 59 is also reduced by the fact that heat transfer brakes 58 are formed in the form of thin spots before the contact point. This is also made possible by the fact that, in contrast to...In conventional systems, less system pressure is required, and no nozzle needs to be sealed. The hot runner system is mechanically combined with a seal. Hot runner nozzle 35 with torpedo union nut 57 56 without torpedo union nut 57 provides a simple combination. The hot runner system has two injection points 36, and thus two connections between the two hot runner nozzles 35 and injection nozzle 34. The connection between 37 and injection nozzle 34 and hot runner nozzle 35 is achieved through dimensioned press fits 38 and / or seals, which can compensate for thermal expansion 37. The press fit on the pipe stub is achieved by a pipe end stub with a wall thickness between and mm. By appropriately selecting the wall thickness of the pipe end stub 5, the system's pipe end stub 5 is suitable for sealing against high pressures and its outer diameter. 28-08-2025-435Ö230 -Main Post -0038PCT / DE2025 / 000088 The heated hot runner system 33 should ideally have no gaps 42 at the connection points of the hot pipe elements 39 to avoid this, so that color changes are possible.To prevent the hot tube elements 39 from being excessively pressed together by the injection pressure, they are held together by frame elements 40 or multi-part frame elements 40. Frame element 40 consists of two half-shells 53 connected to each other. Threaded connectors 54 are located between the two frame elements. Here, preferably two pressure elements, preferably in the form of pressure screws 41, press the hot tube elements 39 together on the frame element 40 or on the threaded connector 54. The hot runner nozzle body 43 and injection nozzle 34 are only connected to the hot runner system at contact points on the frame elements in the assembled state. The hot runner system has few contact points 52 between the hot tube elements 39 and the frame elements, thus minimizing heat loss. The frame element 40 has a spacer ring 55 with small contact points on its upper edge, preferably made of a material that directs the nozzle towards the mold. The invention is described below with reference to the drawings.Closer view from below, needle valve hot runner system 28 with two needle valve nozzles 35 and next to the sprue nozzle. Above the needle valve nozzle, upper diaphragm piston assembly - diaphragm part with the diaphragm sealing edge and diaphragm piston - 28-08-2025-43502301 - Main position t-0033PCT / DE2025 / 000088. The needle 1 between diaphragm piston stiffener 7 and hot runner nozzle 35. 2 through needle valve hot runner system with two needle valve nozzles and next to the sprue nozzle. Above the needle valve nozzle of the diaphragm cylinder, shape of upper diaphragm piston stiffener, diaphragm part 2 with the diaphragm sealing edge and diaphragm piston stiffener. View from above, needle valve hot runner system with two needle valve nozzles and next to the sprue nozzle. Above needle valve nozzle, upper diaphragm piston stiffening, diaphragm part with the diaphragm sealing edge and sealing screw to 4, a hot runner system via needle valve. Mold plates: Top mold mounting plate. Below the mold plate 20, also the diaphragm cylinder cover 24.Membrane part 2 consisting of membrane piston wall, membrane side wall 4 and membrane sealing edge. The seal 25, the membrane cylinder cover and needle shaft seal, form 22 on the mold plate 20 and on the upper of the needle valve hot runner nozzle 29. To be seen 16, the needle stroke over needle head 14 over needle head support plate, membrane piston wall thereby pressed in. The sealing screw 18 adjustment bore with seal, the membrane cylinder. With the connecting screw, the membrane piston stiffener, the upper membrane piston stiffener 6 and the membrane piston stiffener 7 with the membrane piston wall clamped in between. The pneumatic connection bores 27 above the upper membrane piston stiffener 6 and below the lower membrane piston stiffener 7. The membrane cylinder with its piston movement volume is marked. View of heating wire 44 with upward extension and two extensions with double winding 65 and the heating wire ends 46 with deflection 64 double winding. AfterPreferred embodiments of the invention are described with reference to the accompanying drawings, the invention is limited to precise embodiments, and various changes and modifications to it can be carried out by a person skilled in the art without deviating from the scope of the invention as defined in the accompanying claims.

[0002] 28-08-2025-4350230 i-HauP tPos*-004 PCT / DE2025 / 000088 Diaphragm cylinder Diaphragm part Needle Mold plate Needle shaft seal Needle valve hot runner system with clamping housing. Hot runner nozzle with needle valve upper seals Needle valve nozzle Needle shaft Injection nozzle Hot runner nozzle Injection point Press fit Hot tube elements Frame element Pressure screw Intervals Hot runner nozzle body Heating wire Double wire coil Heating wire end Temperature sensor Sheathing tube Hot runner mold Tube stub. Contact points Half shell Threaded connector Spacer ring 28“08_2025_43502301“'HauP tPos 1-0042 PCT / DE2025 / 000088 Lower torpedo union nut Heat transfer brake Contact point Melt channel Mold cavity Mold Nozzle side Connection terminal Deflection Double winding Double winding

Claims

28-08-2025-43502301-KauP iPos i~0044 PCT / DE2025 / 000088 Claims Hot runner distribution system for polymer melts for filling mold cavities, characterized in that several hot tube elements are connected to one another and wrapped with only one heating wire or tubular heater and are provided with a double winding and two further hot tube elements with one of the heating wires extending from the hot tube element. Hot runner distribution system for polymer melts for filling mold cavities according to claim characterized in that hot tube elements are held together by a frame element. Hot runner distribution system for polymer melts for filling mold cavities characterized in that 28-08-2025-43502301-Hau P p □ st-0045 PCT / DE2025 / 000088 Several hot tube elements are connected to each other and wrapped with only one heating wire or tubular heating element, and hot tube elements are provided with a double winding. The heating wire end of the double winding coming from the deflection is preferably provided with a clamping frame housing with a connection terminal. Hot runner distribution system polymer melts for filling mold cavities according to claim characterized in that the system hot runner nozzles with needle valve and needles are preferably moved with a diaphragm cylinder. System polymer melts for filling mold cavities according to claim characterized in that hot tube elements are joined to each other with an interference fit.Hot runner distribution system for polymer melts, the filling of the mold cavity according to the claim is characterized by hot tube elements being joined to each other with a press fit and a heating wire being wound over them, and the winding being designed so that movement between the connected hot tube elements due to thermal expansion is compensated by the heating wire. 28-08-2025-4350230I-HâuP Pos “0048 PCT / DE2025 / 000088 Hot runner distribution system for polymer melts, for filling mold cavities according to claim, characterized in that hot tube elements are held together by a frame element and the frame element is preferably constructed with half-shells, pressure screws and / or threaded connectors. Hot runner distribution system for polymer melts, for filling mold cavities according to claim, characterized in that the hot runner nozzle with or without a needle valve on the mold plate, nozzle direction and hot runner nozzle at the contact point, at least 50°C temperature in the melt channel. Hot runner distribution system for polymer melts, for filling molds according to claim, characterized in that the melt channel, hot runner nozzle with the melt channel of the approaching hot runner distribution system for polymer melts, for filling molds according to claim, characterized in that the orientation with respect to the injection nozzle and hot runner nozzle is 180° but preferably 90° or also another angle.

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