A hot runner injection molding system with side gating
The hot runner injection molding system addresses the complex servicing issue of side gating by implementing self-acting sealing interfaces, ensuring efficient molten material distribution and maintenance, and enhancing thermal management without mechanical joints.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- VASANTHA TOOL CRAFTS PVT LTD
- Filing Date
- 2025-12-05
- Publication Date
- 2026-06-11
Smart Images
Figure IN2025052011_11062026_PF_FP_ABST
Abstract
Description
A HOT RUNNER INJECTION MOLDING SYSTEM WITH SIDE GATINGCROSS REFERENCE TO RELATED APPLICATIONThis Application is based on and derives the benefit of Indian Provisional Application 202441096265 filed on 6thDecember 2024, the contents of which are incorporated herein by reference.TECHNICAL FIELD
[0001] The embodiments herein generally relate to injection molding systems and more particularly to a hot runner injection molding system with side gating of cavity inserts in a linear arrangement or a radial arrangement.BACKGROUND
[0002] A hot runner inj ection molding system is a type of inj ection molding system that enables the efficient flow of molten plastic into mold cavities, keeping it heated until the moment it fills the mold. Unlike conventional cold runner injection molding systems where excess plastic solidifies in the runner channels and requires trimming, the hot runner injection molding system maintains the plastic in a molten state within heated channels, reducing waste and improving production efficiency. The hot runner injection molding system typically includes a heated manifold, nozzles, and temperature controllers. The heated manifold channels the molten plastic from the injection molding machine’s barrel into the various cavities, ensuring consistent and precise flow. The nozzles inject the molten plastic directly into the cavities, while the temperature controllers regulate heat throughout the system to prevent premature solidification.
[0003] Conventionally, the hot runner injection molding system includes vertical gating in which the molten plastic enters a mold cavity vertically, typically from the top or bottom of the mold. In vertical gating, molten plastic is directed vertically into the center or core of the cavity, filling the mold in a balanced and symmetrical pattern. However, some hot runner injection molding systems include side gating, also known as horizontal gating, in which the molten plastic enters a melt block from the nozzle, into the cavity from the side rather than from the top or bottom, making it suitable for parts with flat or asymmetrical shapes. In side gating, the gate components, are placed on the part’ s / component’ s side or edge, directing the flow horizontally into the cavity. This allows the filling of the cavity more precisely, avoiding weld lines and flow marks that could compromise the quality and strength of the final part. The horizontal flow can also help reduce visible defects on the part’s surface, as the molten plastic can be directed more precisely to achieve a smooth, uniform finish.
[0004] Typically, the gate components for side gating include a gate bushing that channels the molten plastic from the melt block to the cavity side through a tip that is threaded with the gate bushing. The threading of the tip with the gate bushing provides sealing between the tip and the gate bushing, thereby preventing leakage of the molten plastic when it flows into the cavity. The mechanical interlocking between the tip and the gate bushing complicates the servicing of the tip, which is a component that requires frequent maintenance and replacement. To service the tip, other sub-assemblies, such as the melt block and nozzle, must be dismantled, making the process timeconsuming and cumbersome.
[0005] Therefore, there exists a need for a hot runner injection molding system with side gating of cavity inserts which obviates the aforementioned drawbacks.OBJECTS
[0006] The principal object of embodiments herein is to provide a hot runner injection molding system with side gating of cavity inserts for simplifying servicing of side gate assembly by eliminating the need to dismantle / dis-assemble other parts of the hot runner injection molding system.
[0007] Another objective of embodiments herein is to provide the hot runner injection molding system with side gating of multiple cavity inserts in linear or radial arrangements.
[0008] Another objective of the embodiments herein is to provide the hot runner injection molding system with side gating assemblies that ensures self-acting sealing at an interface of the side gate components of the side gate assembly under injection pressure of molten material flowing through the side gate components, and thermal expansion of the side gate assembly, thereby eliminating the necessity for a mechanical joint interface between the side gate components of the side gate assembly.
[0009] Another objective of the embodiments herein is to provide the hot runner injection molding system that allow efficient distribution and injection of molten material into multiple cavity inserts while simplifying maintenance and improving thermal management.
[0010] These and other objects of embodiments herein will be better appreciated and understood when considered in conjunction with following description and accompanying drawings. It should be understood, however, that the following descriptions, while indicating embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.BRIEF DESCRIPTION OF DRAWINGS
[0011] The embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:
[0012] Fig. 1 depicts a perspective view of a hot runner injection molding system with side gating of cavity inserts in a radial arrangement, according to embodiments as disclosed herein;
[0013] Fig. 2 depicts a sectional view of the hot runner injection molding system with side gating of cavity inserts in the radial arrangement, according to embodiments as disclosed herein
[0014] Fig. 3 depicts another perspective view of the hot runner injection molding system with side gating of cavity inserts in a linear arrangement, according to embodiments as disclosed herein;
[0015] Fig. 4 depicts a sectional view of the hot runner injection molding system with side gating of cavity inserts in the linear arrangement, according to embodiments as disclosed herein; and
[0016] Fig. 5 depicts a sectional view of a side gate assembly, according to embodiments as disclosed herein.DETAILED DESCRIPTION
[0017] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.
[0018] The words / phrases "exemplary", “example”, “illustration”, “in an instance”, “and the like”, “and so on”, “etc.”, “etcetera”, “e.g.,”, “i.e.,” are merely used herein to mean "serving as an example, instance, or illustration. Any embodiment or implementation of the present subject matter described herein using the words / phrases "exemplary", “example”, “illustration”, “in an instance”, “and the like”, “and so on”, “etc.”, “etcetera”, “e.g.,”, “i.e.,” is not necessarily to be construed as preferred or advantageous over other embodiments.
[0019] The accompanying drawings are used to help easily understand various technical features and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any modifications, equivalents, and substitutes in addition to those which are particularly set out in the accompanying drawings and the corresponding description. Usage of words such as first, second, third etc., to describe components / elements / steps is for the purposes of this description and should not be construed as sequential ordering / placement / occurrence unless specified otherwise.
[0020] The embodiments herein achieve a hot runner injection molding system that simplifies servicing of the side gate assembly by eliminating the need to dismantle / disassemble other parts of the hot runner injection molding system. Further, the embodiments herein achieve the hot runner injection molding system with side gating of multiple cavity inserts linear or radial arrangements. Referring now to the drawings Figs. 1 through 5, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.
[0021] Fig. 1 depicts a perspective view of the hot runner injection molding system (1000) with radial arrangement of cavity inserts (1300), according to embodiments as disclosed herein. Fig. 3 depicts a perspective view of the hot runner injection molding system (1000) with linear arrangement of cavity inserts (1300), according to embodiments as disclosed herein. In an embodiment, the hot runner injection molding system (1000) includes a nozzle assembly (1100), a melt block assembly (1200 A, 1200B), one or more than one cavity inserts (1300) and one or more than one side gate assemblies (1400). The nozzle assembly (1100) is coupled to a manifold (not shown in figures) to receive the molten material. The melt block assembly (1200A, 1200B) is connected to the nozzle assembly (1100). Each side gate assembly (1400) is connected to the melt block assembly (1200A, 1200B). Each cavity insert (1300) is adapted to be connected to the melt block assembly (1200A, 1200B) through the corresponding side gate assembly (1400). This configuration allows for effective side gating of the cavity inserts (1300) with the nozzle assembly (1100). The nozzle assembly (1100) is configured to receive molten material from the manifold (not shown in figures) of the system (1000) and transfer it to the melt block assembly (1200 A, 1200B). The melt block assembly (1200A, 1200B) is configured to distribute the molten material in a sidewise / horizontal direction into each cavity insert (1300) through the corresponding side gate assembly (1400).
[0022] As shown in fig. 2, in an embodiment, the nozzle assembly (1100) includes a nozzle (1102), a flange (1104), a manifold plate (1106), a nozzle heater (1108), a guiding member (1110), a wave spring (1112), a heater washer (1114) and a heater retainer (1116). The nozzle (1102) is adapted to receive the molten material from the manifold. The flange (1104) is connected to a top end of thenozzle (1102) and is adapted to mount the nozzle (1102) on the manifold plate (1106). Further, the flange (1104) is adapted to restrict radial movement of the nozzle (1102) and to maintain concentricity of the nozzle assembly (1100) with respect to the melt block assembly (1200A, 1200B). The manifold plate (1106) is adapted to mount / support the nozzle (1102) along with the nozzle heater (1108) thereon. The guiding member (1110) is adapted to couple the nozzle assembly (1100) to the melt block assembly (1200A, 1200B). The guiding member (1110) is in fluid communication with the nozzle (1102) to receive the molten material from the nozzle (1102). A portion of the guiding member (1110) is inserted into a bottom end of the nozzle (1102), and the guiding member (1110) is thread fitted to the nozzle (1102) such that another portion of the guiding member (1110) is positioned outside the nozzle (1102). It is also within the scope of the invention to connect the guiding member (1110) to the nozzle (1102) by using clamps, snap fits, locking pins, fasteners or any other temporary joints or permanent joints. Further, it is also within the scope of the invention to provide the guiding member (1110) as an integral part of the nozzle (1102).
[0023] Further, the wave spring (1112) is mounted on or near to a first end (top end) of the nozzle (1102). For example, the wave spring (1112) is provided on the nozzle (1102) and is loaded in between a top end of the nozzle heater (1108) and the flange (1104). The wave spring (1112) is configured to exert an axial force on the nozzle assembly (1100) in a direction towards the melt block assembly (1200 A, 1200B) thereby allowing the nozzle assembly (1100) to maintain seating pressure against the melt block assembly (1200A, 1200B). The nozzle heater (1108) is coupled with the nozzle (1102) and is configured to heat the nozzle (1102) through the plurality of nozzle heating elements (1109) to facilitate uniform heating of the nozzle (1102) thereby ensuring a homogenous flow of the molten material through a channel defined in the nozzle (1102). The heater washer (1114) and the heater retainer (1116) are mounted on the nozzle (1102) and are in contact with the nozzle heater (1108) to restrain displacement of the nozzle heater (1108) with respect to the nozzle (1102).
[0024] As shown in fig. 2, in an embodiment, the melt block assembly (1200 A, 1200B) includes a melt block (1202A, 1202B), a melt block snorkel (1204), a melt block heater (1206), a locator (1208), a first retainer (1210), a disc spring (1212), a low head screw (1214), a support pad (1216), a second retainer (1218), a plurality of manifold plugs (1220), a plurality of manifold plug crush rings (1222) and a plurality of grub screws (1224). The melt block assembly (1200A, 1200B) is adapted to convert axial molten material flow from the nozzle assembly (1100) into horizontal molten material flow into the cavity inserts (1300) via the side gate assemblies (1400). The melt block snorkel (1204) is adapted to couple the nozzle (1102) to the melt block (1202A, 1202B). The melt block snorkel (1204) is adapted to receive the molten material from the nozzle (1102) via the guiding member (1110) and transfer the molten material to the melt block (1202A, 1202B). One end (topend) of the melt block snorkel (1204) is coupled with the nozzle (1102) through the guiding member (1110) and another end (bottom end) of the melt block snorkel (1204) is coupled (thread fitted) with the melt block (1202A, 1202B). A first portion (1204A) (as shown in fig. 4) of the melt block snorkel (1204) is inserted or guided into a bottom end of the guiding member (1110) of the nozzle assembly (1100) such that the guiding member (1110) slides over the first portion of the melt block snorkel (1204) for compensating thermal expansion of the nozzle assembly (1100) thereby restricting force or stress transfer to the melt block assembly (1200 A, 1200B) or the side gate assemblies (1400). A second portion (1204B) (as shown in fig. 4) of the melt block snorkel (1204) is removably connected (thread fitted) to the melt block (1202A, 1202B). It is also within the scope of the invention to connect the melt block snorkel (1204) to the melt block (1202A, 1202B) by using clamps, snap fits, locking pins, fasteners or any other temporary joints or permanent joints. Further, it is also within the scope of the invention to provide the melt block snorkel (1204) as an integral part of the melt block (1202A, 1202B). An intermediate portion (1204C) (as shown in fig. 4) of the melt block snorkel (1204) is positioned outside the guiding member (1110) and the melt block (1202A, 1202B). The intermediate portion (1204C) of the melt block snorkel (1204) is adapted to connect the first portion of the melt block snorkel (1204) to the second portion of the melt block snorkel (1204). The intermediate portion (1204C) of the melt block snorkel (1204) defines a hexagonal profile adapted to facilitate tightening (screwing) of the melt block snorkel (1204) with respect to the melt block (1202B) by using tools.
[0025] In an embodiment, the melt block snorkel (1204) includes a converging section (1204V) (as shown in fig. 2) provided at its inlet portion, wherein the converging section (1204V) is configured to regulate the molten material entering the passage and creates an injection pressure zone. For example, the converging section (1204V) of the melt block snorkel (1204) is adapted to constrict the flow of the molten material entering the passage defined in the melt block snorkel (1204). As the molten material flows from the nozzle (1102), into the guiding member (1110), and the melt block snorkel (1204), an injection pressure of the molten material on the melt block snorkel (1204) created by the constricted flow at the converging section (1204V), and thermal expansion of the melt block snorkel (1204) due to the heat expelled by the molten material, create a self-acting sealing interface between the melt block snorkel (1204) and the guiding member (1110), thereby preventing leakage of the molten material at a junction between the guiding member (1110) and the melt block snorkel (1204). The creation of the self-acting sealing interface between the melt block snorkel (1204) and the guiding member (1110) due to the injection pressure and thermal expansion of the melt block snorkel (1204), therefore compensates for the thermal expansion of the nozzle assembly (1100). The melt block snorkel (1204) is adapted to allow the molten material to flow from the nozzle (1102) into the melt block (1202A, 1202B), wherein the melt block (1202A, 1202B) is configured to distributethe molten material into each cavity insert (1300) through the corresponding side gate assembly (1400). The melt block snorkel (1204) is adapted to absorb the thermal expansion of the nozzle (1102) inside the melt block (1202) thereby restricting force or stress transfer to the melt block (1202 A, 120B) or the plurality of side gate assemblies (1400). The melt block (1202 A, 1202B) is positioned inside the cavity plate.
[0026] The melt block (1202) includes a plurality of flow channels, wherein each flow channel is configured to direct the molten material toward the corresponding side gate assembly (1400) and the cavity insert (1300) in the sidewise direction of the melt block (1202 A, 1202B). Further, the melt block heater (1206) is coupled with the melt block (1202A, 1202B) through the low head screw (1214) (as shown in fig. 4). The melt block heater (1206) includes a plurality of melt block heating elements (1207) (as shown in fig. 2) configured to heat the melt block (1202) and the melt block snorkel (1204) to allow a uniform flow of the molten material in the melt block assembly (1200). The melt block heater (1206) can also be called as a side heater. The locator (1208) is provided on a top end of the melt block (1202A, 1202B). The locator (12080 is adapted to locate or position the melt block assembly (1200 A, 1200B) with respect to a cavity plate (not shown in figures) of the hot runner injection molding system (1000). Further, the locator (1208) is adapted to maintain concentricity of the melt block assembly (1200A, 1200B) with respect to the nozzle assembly (1100). The first retainer (1210) is mounted onto the top end of the melt block (1202A, 1202B) adjacent to an inner base wall of the locator (1208) for retaining the locator (1208) onto the melt block (1202A, 1202B). The disc spring (1212) is provided on the melt block (1202 A, 1202B) and is loaded between an outer base wall of the locator (1208) and a top face of the melt block (1202A, 1202B). The disc spring (1212) is adapted to exert spring force onto the melt block assembly (1200 A, 1200B) thereby allowing the melt block assembly (1200A, 1200B) to maintain seating pressure against the cavity plate.
[0027] The support pad (1216) is provided at a bottom end of the melt block (1202A, 1202B). The support pad (1216) is adapted to support or locate the melt block assembly (1200A, 1200B) onto the cavity plate. Further, the support pad (1216) is adapted to maintain concentricity of the melt block assembly (1200A, 1200B) with respect to the nozzle assembly (1100). A portion of the support pad (1216) is adapted to be inserted into / received by a support pad receiving portion (cavity) (not shown in figures) of the melt block (1202A, 1202B). The second retainer (1218) is provided onto the bottom end of the melt block (1202 A, 1202B) adjacent to an inner base wall (inner melt block seating wall) of the support pad (1216) for retaining the support pad (1216) onto the melt block (1202 A, 1202B). Furthermore, each manifold plug (1220) is provided in fluid communication with a central flow channel of the melt block assembly (1200). Each manifold plug (1220) is connected with the melt block (1202 A, 1202B) through a corresponding grub screw (1224) and a corresponding manifold plugcrush ring (1222) (as shown in fig. 4). The plurality of manifold plugs (1220) are adapted to facilitate managing of the flow of molten material through the plurality of flow channels of the melt block (1202 A, 1202B).
[0028] As shown in figs (1 and 2), in an embodiment, the melt block (1202A) is a cylindrical melt block that is adapted to facilitate the radial arrangement of the cavity inserts (1300) around the cylindrical face of the melt block (1202A) of the melt block assembly (1200A). As shown in fig. 3, in another embodiment, the melt block (1202B) is a cuboidal melt block that is adapted to facilitate the linear arrangement of the cavity inserts (1300) along the side faces of the melt block (1202B) (as shown in fig. 3) of the melt block assembly (1200B).
[0029] As shown in figs. 2 and 5, in an embodiment, each side gate assembly (1400) includes a side gate snorkel (1402) and a side gate tip (1404). The side gate snorkel (1402) of each side gate assembly (1400) is positioned inside the melt block assembly (1200A, 1200B) and is provided in fluid communication with a corresponding flow channel of the melt block (1202 A, 1202B) to receive the molten material therefrom. The side gate snorkel (1402) is slidably connected with the melt block (1202 A, 1202B). In an embodiment, the melt block (1202 A, 1202B) includes a plurality of snorkel receiving channels (not shown in figures), each adapted to receive the side gate snorkel (1402) of the respective side gate assembly (1400). The side gate tip (1404) of each side gate assembly (1400) is positioned outside the melt block (1202A, 1202B) and is provided in surface contact with the respective side gate snorkel (1402). The side gate tip (1404) of each side gate assembly (1400) is adapted to be coupled with the corresponding cavity insert (1300). For example, a first end (1404A) of the side gate tip (1404) is in engagement / surface contact with the side gate snorkel (1402), and a second end (1404B) of the side gate tip (1404) is coupled with the respective cavity insert (1300). Further, each side gate assembly (1400) includes a nut (1410) coupled with the side gate tip (1404) by receiving a portion of the side gate tip (1404) therethrough, wherein the nut (1410) is adapted to be connected (thread fitted) with the corresponding cavity insert (1300), thereby connecting the sidegate tip (1404) with the corresponding cavity insert (1300). The side gate tip (1404) of each side gate assembly (1400) is provided in fluid communication with the respective side gate snorkel (1402) to receive the molten material therefrom. The side gate snorkel (1402) of each side gate assembly (1400) is adapted to receive the molten material through the corresponding flow channel of the melt block (1202A, 1202B), and the side gate tip (1404) is configured to inject the molten material into a cavity defined in the corresponding cavity insert (1300) to form a component. Furthermore, the side gate snorkel (1402) of each side gate assembly (1400) includes a converging section (1402V) (as shown in fig. 5) provided towards a first end portion / inlet portion of the side gate snorkel (1402), wherein the molten material from the corresponding flow channel of the melt block (1202A, 1202B) isconfigured to enter the side gate snorkel (1402) of each side gate assembly (1400) via the converging section (1402V) and flow through a passage defined in the side gate snorkel (1402), and the molten material flows in a direction towards an outlet defined in the side gate tip (1404). The converging section (1402V) of the side gate snorkel (1402) of each side gate assembly (1400) is adapted to regulate the molten material entering the passage and creates an injection pressure zone. For example, the converging section (1402V) of the side gate snorkel (1402) of each side gate assembly (1400) is adapted to constrict the flow of the molten material entering the passage defined in the side gate snorkel (1402) thereby creating injection pressure on the side gate snorkel (1402). As the molten material flows from the nozzle (1102), into the melt block (1202), and the side gate assembly (1400), an injection pressure of the molten material on the side gate snorkel (1402) created by the constricted flow at the converging section (1402V), and thermal expansion of the side gate tip (1404) and the side gate snorkel (1402) due to the heat expelled by the molten material, create a second self-acting sealing interface between the side gate snorkel (1402) and the side gate tip (1404), thereby preventing leakage of the molten material at a junction between the side gate tip (1404) and the side gate snorkel (1402). The creation of the second self-acting sealing interface between the side gate snorkel (1402) and the side gate tip (1404) due to the injection pressure and thermal expansion of the side gate assembly (1400), therefore overcomes the need to provide a mechanical joint interface between the side gate tip (1404) and the side gate snorkel (1402).
[0030] Further, the injection pressure on the side gate snorkel (1402) combined with the thermal expansion of the side gate snorkel (1402), create a third self-acting sealing interface between the inlet portion of the side gate snorkel (1402) and the corresponding flow channel of the melt block (1202A, 1202B) thereby preventing leakage of the molten material.
[0031] As shown in fig. 5, In an embodiment, each side gate assembly (1400) further includes at least one biasing member (1406) and a washer (1408) coupled with the side gate snorkel (1402), wherein the biasing member (1406) is held in place on the side gate snorkel (1402) by the washer (1408). The biasing member (1406) is adapted to exert a preloading force (spring force) on the side gate snorkel (1402) in a direction toward the side gate tip (1404) thereby maintaining the surface contact of the side gate tip (1404) with the side gate snorkel (1402). Further, this preloading force (spring force) assists in sealing the side gate snorkel (1402) with the side gate tip (1404) and holds the side gate snorkel (1402) in position within the melt block (1202 A, 1202B), thereby preventing the loosening of the side gate snorkel (1402) with respect to the melt block (1202A, 1202B). Further, when the side gate tip (1404) is engaged with the melt block (1202A, 1202B), the side gate tip (1404) is pushed against the side gate snorkel (1402) to allow alignment of the side gate tip (1404) with the side gate snorkel (1402). The biasing member (1406) allows the side gate snorkel (1402) to be pushedinwards into the melt block (1202 A, 1202B) and return to its original position in the snorkel receiving channel of the melt block (1202 A, 1202B), thereby allowing the side gate tip (1404) to align with the side gate snorkel (1402). In an embodiment, the biasing member (1406) is a bevel spring / disc spring. However, it is also within the scope of the invention to provide any other type of biasing members for exerting spring force onto the side gate snorkel (1402) without otherwise deterring the intended function of the biasing member (1406) as can be deduced from the description and corresponding drawings. In an embodiment, each of the side gate snorkel (1402) and the side gate tip (1404) have a chamfer end surface (1402C, 1404C) (as shown in fig. 5), wherein the chamfer end surfaces (1402C, 1404C) facilitates alignment and engagement of the side gate tip (1404) and the side gate snorkel (1402) with respect to each other as well as the melt block (1202 A, 1202B).
[0032] When the system (1000) is turned off, the flow of molten material in the system (1000) stops, thereby releasing the injection pressure on the side gate snorkel (1402) and relieving the thermal expansion of the side gate tip (1404) and the side gate snorkel (1402). This loosens the side gate tip (1404) from the side gate snorkel (1402), allowing the side gate tip (1404) to easily disengage from the melt block assembly (1200). In an embodiment, the side gate tip (1404) of each side gate assembly (1400) is disengaged from the respective side gate snorkel (1402) by removing the respective cavity insert (1300) from a mounting plate through which the cavity insert (1300) is mounted in the system (1000). This facilitates ease in servicing the side gate tip (1404), a component that needs frequent maintenance and replacement. Further, by eliminating the need to provide the mechanical joint interface between the side gate tip (1404) and the side gate snorkel (1402), the system (1000) allows servicing of the side gate tip (1404) without the need to disassemble the melt block assembly (1200A, 1200B) and the nozzle assembly (1100).
[0033] The technical advantages of the hot runner injection molding system (1000) with side gating of cavity inserts (1300) are as follows. Ease in servicing the side gate tip (1404) of the side gate assembly (1400) without the need to dismantle / disassemble the melt block assembly (1200A, 1200B) and the nozzle assembly (1100)of the system (1000). The self-acting sealing at an interface of the side gate components (1402, 1404) of the side gate assembly (1400) under injection pressure of molten material flowing through the side gate components (1402, 1404), and thermal expansion of the side gate assembly (1400) eliminates the need to provide a mechanical joint interface between the side gate tip (1404) and the side gate snorkel (1402). The hot runner injection molding system (1000) allows side gating of multiple cavity inserts (1300) in linear and radial arrangements. The hot runner injection molding system (1000) allows efficient distribution and injection of molten material into multiple cavity inserts (1300) while simplifying maintenance and improving thermal management.
[0034] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and / or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modifications within the spirit and scope of the embodiments as described herein.
Claims
STATEMENT OF CLAIMSWe Claim:
1. A hot runner injection molding system (1000) comprising: a nozzle assembly (1100) having a nozzle (1102) configured to receive molten material; a melt block assembly (1200 A, 1200B) having a melt block (1202 A, 1202B) coupled with the nozzle (1102); one or more than one cavity inserts (1300); and one or more than one side gate assemblies (1400), wherein each side gate assembly (1400) comprises: a side gate snorkel (1402) slidably connected with the melt block (1202 A, 1202B); and a side gate tip (1404), wherein a first end (1404A) of the side gate tip (1404) is engaged with the side gate snorkel (1402), and a second end (1404B) of the side gate tip (1404) is coupled with the respective cavity insert (1300).
2. The hot runner injection molding system (1000) as claimed in claim 1, wherein the side gate snorkel (1402) and the side gate tip (1404) are configured to form a self-acting sealing interface therebetween under at least one of injection pressure of the molten material flowing through the side gate snorkel (1402), and thermal expansion of the side gate snorkel (1402) and the side gate tip (1404) thereby preventing leakage of molten material.
3. The hot runner injection molding system (1000) as claimed in claim 1, wherein the first end (1404A) of the side gate tip (1404) is in surface contact with the side gate snorkel (1402), wherein each side gate assembly (1400) includes: at least one biasing member (1406) configured to apply a pre-loading force onto the respective side gate snorkel (1402) in a direction towards the side gate tip (1404) for pushing the side gate snorkel (1402) against the side gate tip (1404) thereby maintaining the surface contact of the side gate tip (1404) with the side gate snorkel (1402).
4. The hot runner injection molding system (1000) as claimed in claim 1, wherein the nozzle assembly (1100) includes: a nozzle heater (1108) comprising a plurality of nozzle heating elements (1109) configured to uniformly heat the nozzle (1102); and a guiding member (1110) connected to the nozzle (1102).
5. The hot runner injection molding system (1000) as claimed in claim 4, wherein the melt block assembly (1200 A, 1200B) comprises: a melt block snorkel (1204) configured to be connected with the guiding member (1110) thereby coupling the melt block (1202A, 1202B) with the nozzle (1102) of the nozzle assembly (1100); and a melt block heater (1206) having a plurality of melt block heating elements (1207) configured to maintain uniform temperature within the melt block (1202 A, 1202B), wherein a first portion (1204 A) of the melt block snorkel (1204) is inserted or guided into bottom end of the guiding member (1110) of the nozzle assembly (1100) and a second portion (1204B) of the melt block snorkel (1204) is connected to the melt block (1202A, 1202B); and the melt block snorkel (1204) is configured to compensate for thermal expansion of the nozzle assembly (1100) thereby restricting force or stress transfer to the melt block assembly (1200A, 1200B).
6. The hot runner injection molding system (1000) as claimed in claim 5, wherein the melt block snorkel (1204) includes a converging section (1204V) provided at its inlet portion, wherein the converging section (1204V) is configured to constrict the molten material entering the melt block snorkel (1204) thereby generating injection pressure combined with thermal expansion of the melt block snorkel (1204) for facilitating formation of a self-acting sealing interface between the melt block snorkel (1204) and the guiding member (1110), thereby preventing leakage of the molten material at a junction between the guiding member (1110) and the melt block snorkel (1204).
7. The hot runner injection molding system (1000) as claimed in claim 1, wherein the side gate snorkel (1402) of each side gate assembly (1400) includes a converging section (1402V) provided at its inlet portion, wherein the converging section (1402V) is configured to constrict the molten material entering the side gate snorkel (1402) thereby generating injection pressure combined with thermal expansion of the side gate snorkel (1402) and the side gate tip (1404) for facilitating formation of the self-acting sealing interface between the side gate snorkel (1402) and the side gate tip (1404).
8. The hot runner injection molding system (1000) as claimed in claim 7, wherein each of the side gate tip (1404) and the side gate snorkel (1402) of each side gate assembly (1400) comprise chamfered end surfaces (1402C, 1404C) configured to facilitate self-alignment and engagement of the side gate tip (1404) with the side gate snorkel (1402); andthe injection pressure on the side gate snorkel (1402) combined with the thermal expansion of the side gate snorkel (1402) create a self-acting sealing interface between the inlet portion of the side gate snorkel (1402) and the corresponding flow channel of the melt block (1202 A, 1202B) thereby preventing leakage of the molten material.
9. The hot runner injection molding system (1000) as claimed in claim 1, wherein the side gate tip (1404) of each side gate assembly (1400) is configured to disengage from the respective side gate snorkel (1402) upon removal of the respective cavity insert (1300) when the system (1000) is turned off, thereby facilitating servicing or replacement of the side gate tip (1404) without disassembly of the melt block assembly (1200A, 1200B) or the nozzle assembly (1100); and the melt block (1202A) of the melt block assembly (1200A) is a cylindrical melt block configured to facilitate radial arrangement of the cavity inserts (1300).
10. The hot runner injection molding system (1000) as claimed in claim 1, wherein the melt block (1202B) of the melt block assembly (1200B) is a cuboidal melt block configured to facilitate linear arrangement of the cavity inserts (1300).