INSULATION BODY AND INJECTION MOLDING TOOL WITH SUCH AN INSULATION BODY

Description

[0001] The invention relates to an insulating body of an injection molding tool for thermally insulating a first component from a second component of the injection molding tool, or to an insulating body as a component of a component of the injection molding tool, wherein the insulating body comprises a metal formed directly from a metallic melt and having an amorphous structure. The invention further relates to an injection molding tool with such an insulating body for thermally insulating a first component from a second component of the injection molding tool. STATE OF THE ART

[0002] For example, US 2019 / 0160719 A1 discloses insulation bodies of an injection molding tool for thermally insulating a hot runner manifold body from another tool body configured as a nozzle head. The plate-shaped hot runner manifold is located at the front and rear between two tool bodies, and a hot runner nozzle is arranged on the hot runner manifold body so that plasticized plastic melt can be transferred from the hot runner manifold body into the hot runner nozzle and finally into a mold cavity. The hot runner manifold body and the hot runner nozzle have a temperature at which a plastic melt can be kept flowable, while the surrounding tool bodies, for example, have only room temperature or a slightly elevated temperature, which is, however, significantly lower than the temperature of the hot runner nozzle and the hot runner manifold body.To minimize heat transfer from the hot runner manifold body to the surrounding mold bodies, insulation bodies in the form of pressure pieces are known. These are designed to minimize the heat flow from the hot runner manifold body to the surrounding mold bodies. For example, pressure pieces or nozzle heads can be designed with smaller material cross-sections or contact surfaces to minimize heat conduction. However, the material of the pressure pieces is usually made of the same heat-conducting steel as the material of the other mold bodies, particularly due to the necessary mechanical strength.

[0003] US 7,845,936 B2 shows another insulation body in an injection mold for thermally insulating a first component from a second component of the injection mold, namely for accommodating the hot runner nozzle on the hot runner manifold body, so that the insulation body forms a nozzle head. The nozzle head also rests against the low-temperature mold body, and the transition area of ​​the nozzle head, which ultimately serves for contact with the cold mold body, has a reduced cross-section to minimize heat flow into the cold mold body.

[0004] Thus, insulating bodies are known as components of injection molding tools. These serve to thermally insulate a first component from a second component of the injection molding tool, although the achievable thermal insulation effect is only minimal. Hot runner nozzles, for example, can also have sections made of materials that enable reduced heat transfer, for example, to the mold for forming the cavity itself, particularly through corresponding cross-sectional reductions or small contact surfaces. Disadvantageously, the insulating bodies as components of injection molding tools are made of a material that otherwise has a high thermal conductivity, for example, approximately 15 to 50 W / mK or even significantly higher.Conventional metallic materials exhibit very high thermal conductivities, and insulating bodies of the type in question here must also bear high forces, necessitating the use of conventional metallic materials anyway. The use of ceramics for such insulating bodies is also known, but their brittle nature limits their application.

[0005] EP 4 086 059 A1 and WO 2020 / 050851 A1 each disclose an insulating body of an injection molding tool for thermally insulating a component of the injection molding tool, wherein the insulating body comprises a metal that is formed directly from a metallic melt and has an amorphous structure. The insulating body made of the amorphous structure is designed as a surface coating or as a cover body and thus essentially forms a two-dimensional body on the molding surface of the injection molding tool, which is intended to come into contact with the plastic melt and thermally insulate it when the injection molding tool is in use and a plasticized plastic melt is injected into its cavity. The amorphous metal, also called metallic solid glass, therefore does not form a functional three-dimensional component of the injection molding tool. DISCLOSURE OF THE INVENTION

[0006] The object of the invention is to further improve an insulating body of an injection molding tool for thermally insulating a first component from a second component of the injection molding tool and / or as a component of a component of the injection molding tool. The insulating body should exhibit the lowest possible thermal conductivity while simultaneously maintaining high mechanical strength.

[0007] The object of the invention is achieved starting from an insulating body according to the preamble of claim 1 and starting from an injection molding tool according to the preamble of claim 9 with the respective characterizing features. Advantageous developments of the invention are specified in the dependent claims.

[0008] To achieve the object and to provide a corresponding insulating body, the invention provides that the insulating body forms a pressure piece for arrangement between a hot runner manifold body and a tool body and / or that the insulating body forms a nozzle head for receiving a hot runner nozzle on the hot runner manifold body and / or that the insulating body forms an attachment for arrangement on a nozzle tip of a hot runner nozzle and / or that the insulating body forms a component of a one-piece hot runner nozzle.

[0009] So-called amorphous metals or metallic glasses comprise metal alloys or metal-nonmetal alloys that are not based on a metal lattice but possess an amorphous structure. There are also solid metallic glasses that can form insulating bodies, such as those used for an injection molding tool or as a component of an injection molding tool, or that can be used in a manner suitable for an injection molding tool. The concept of the invention is therefore based on constructing known insulating bodies in an injection molding tool from a completely new material, which is referred to as an amorphous metal, an amorphous alloy, or a so-called metallic glass.

[0010] Amorphous metals also develop an amorphous structure, similar to that of silicon-based glasses, by preventing natural crystallization. Crystallization is usually prevented by very rapid cooling, which can be achieved, for example, by shock freezing a metallic melt. This deprives the atoms of their mobility before they can arrange themselves into a crystal order, resulting in an amorphous structure, and the melt solidifies as it is. Alternatively, a metallic melt can be created by adding certain alloying constituents, such as zirconium as a glass-forming agent.

[0011] Generally, the molten state of the metal must be frozen. The advantage of a 3D printing process is the small melt volume required, provided that too much energy is not applied, as otherwise a crystalline structure will develop. Care must be taken to ensure that the crystallization temperature of the underlying layers is not exceeded when applying additional layers, as otherwise crystallization nuclei can also form.

[0012] Due to their excellent glass-forming properties, alloys suitable for injection molding allow the production of components with wall thicknesses of up to 5 mm, for example. The cooling rates achieved are usually sufficient to freeze the molten metal.

[0013] Typically, alloys of at least two metals, or of one metal and one non-metal, that are capable of amorphization are required. Pure metals can also be used, such as ferrite, to which a so-called glass-forming agent, such as boron or phosphorus, is added, for example, in the composition Fe 4 B. Technically relevant amorphous metals are therefore usually special alloys of several elements for which the required cooling rate is technically achievable. The cooling rate can be in the range of, for example, 10 6 < Ks. At slower cooling rates, crystallization occurs, which is precisely what is to be avoided for amorphous metals.

[0014] Amorphous metals of interest here can have thermal conductivities of, for example, only 2.5 W / mK, while still achieving a Vickers hardness (HV5) of 540. With these values, an insulating body made of an amorphous metal results in very low thermal conductivity with otherwise very high strength, which can be used according to the invention for injection molding tools or as a component for injection molding tools.

[0015] Particularly advantageously, the insulation body is formed as a single piece and manufactured, in particular, using a generative manufacturing process. This allows the insulation body to be freely designed, for example, with a ribbed or lamellar structure, a honeycomb structure, or any other structure with webs and lamellae and corresponding cavities, openings, or internal chambers. The geometric structure of the insulation body can be selected so that the insulation body can withstand high loads in the main loading direction, while at the same time achieving a small material cross-section in order to minimize heat conduction from a first component to a second component of the injection molding tool, even geometrically.In particular, generative manufacturing processes offer a high degree of design freedom with internal cavities, undercuts, lateral openings and the like, so that the insulating body made of the amorphous metal can have both material-specific features and form geometric structures that minimize heat conduction between two components.

[0016] In particular, the one-piece design of the insulation body allows it to be handled individually and avoids connecting elements, fastening elements and the like, in particular screws, rivets or other fastening elements made of highly conductive material, which results in a further optimization of minimal heat conduction.

[0017] According to the invention, the insulation body is designed as a pressure piece for arrangement between a hot runner manifold body and a tool body of the injection molding tool. Pressure pieces are usually screwed onto the hot runner manifold body or the tool body and form spacer elements to maintain a geometric distance between the hot hot runner manifold body and the cold tool body. Consequently, it is particularly advantageous if the insulation body forms such a pressure piece, since the pressure piece is in contact with both a hot component and a cold component, and minimal heat transfer leads to an optimal energy structure of the injection molding tool. Tool bodies can be, for example, a clamping plate or a mold plate, between which the hot runner manifold body, which is usually also plate-shaped, is arranged with a corresponding parallel spacing.

[0018] Alternatively or additionally, according to the invention, the insulating body forms a nozzle head for receiving a hot runner nozzle on a hot runner manifold body, wherein the nozzle head can be in contact with both the hot runner manifold body and another tool body. Nozzle heads are generally used to receive hot runner nozzles on the hot runner manifold body, for example via a threaded connection, and the nozzle head can sit in a planar, movable manner on a connection surface of the hot runner manifold body in order to compensate for heat-induced drift movements between the tool parts. In this respect, the nozzle head is also arranged between a hot first component and a cooler second component, so that further energy optimization of the injection molding tool results from the fact that a nozzle head is also designed as an insulating body according to the invention, which in particular no longer has its own heating elements.

[0019] According to yet another embodiment of the invention, the insulating body forms an attachment, which serves as a particularly annular individual part for arrangement on a nozzle tip of a hot runner nozzle. The attachment can, for example, be screwed or pressed onto the nozzle tip and forms the component which, as a component of the hot runner nozzle and thus also as a component of the injection molding tool, is brought into contact with a mold, for example which forms the cavity for the injection molding itself. It is also conceivable for the insulating body to form a component of a one-piece hot runner nozzle. This can be implemented by applying the insulating body, as a component of the one-piece hot runner nozzle, to a base body of the hot runner nozzle made of a different material, for example tool steel, using the generative manufacturing process.This takes advantage of the fact that the very low thermal conductivity of the attachment, due to the material comprising the amorphous metal, results in only minimal heat input from the hot runner nozzle into the tool body and thus forms an insulating body that structurally merges into another body in one piece.

[0020] The insulating body can contain zirconium as a glass former and thus be zirconium-based. For example, the insulating body can, in particular, comprise a material comprising the alloy Zr 52.5 Ti 5 Cu 17.9 Ni 14.6 Al 10.

[0021] The invention further relates to an injection molding tool with an insulating body for thermally insulating a first component from a second component of the injection molding tool, wherein the insulating body comprises a metal that is formed directly from a metallic melt and has an amorphous structure. According to the invention, it is provided that the insulating body forms a pressure piece for arrangement between a hot runner manifold body and a tool body and / or that the insulating body forms a nozzle head for receiving a hot runner nozzle on the hot runner manifold body and / or that the insulating body forms an attachment for arrangement on a nozzle tip of a hot runner nozzle and / or that the insulating body forms a component of a one-piece hot runner nozzle.The further features and advantages of the amorphous structure and the metal made of an amorphous material, which are described above in connection with the insulating body, apply in the same way to the injection molding tool according to the invention, wherein the injection molding tool can have a plurality of insulating bodies of different designs.

[0022] The insulating body of the injection molding tool can be formed as a single piece and / or manufactured using a generative manufacturing process. Furthermore, the insulating body can form a pressure piece for placement between a hot runner manifold body and a tool body, which pressure piece is created by the insulating body. Finally, the injection molding tool can have a nozzle head for receiving a hot runner nozzle on the hot runner manifold body, which nozzle head is formed by the insulating body.

[0023] Alternatively and / or particularly advantageously, the injection molding tool comprises a hot runner nozzle for guiding a plasticized plastic melt from the hot runner manifold into a mold, with the insulation body forming an attachment for placement on a nozzle tip of the hot runner nozzle. When the hot runner nozzle is installed in the injection molding tool, the attachment can be picked up at the nozzle tip and brought into contact with the mold, which also forms the cavity for the injection molding. Due to the attachment on the amorphous metal, only a very small amount of heat is transferred from the hot hot runner nozzle to the cold mold, as the attachment serves as an insulation body.

[0024] The injection molding tool can also form an insulating body as a component of a one-piece hot runner nozzle by applying the insulating body as a component of a one-piece hot runner nozzle using a generative manufacturing process. The amorphous metal is applied using the generative manufacturing process, for example, to a base body made of a different material, such as tool steel. The insulating body forms, for example, the upper nozzle tip of the hot runner nozzle, which ultimately has sections that serve to contact the injection molding tool. The amorphous metal can also be applied to other components of an injection molding tool not specified here, and the applied amorphous metal then forms an insulating body as a structural section of the component.The insulating body made of amorphous metal can also form only sections of a spacer body and / or a nozzle head or another component. PREFERRED EMBODIMENTS OF THE INVENTION

[0025] Further measures improving the invention are described in more detail below, together with the description of preferred embodiments of the invention, with reference to the figures. It shows: Figure 1 shows a perspective view of a hot runner manifold body with hot runner nozzles, pressure pieces and nozzle heads arranged thereon, Figure 2 shows a cross-sectional view of the arrangement of the hot runner manifold body between two tool bodies, Figure 3 shows a perspective view of a nozzle head, Figure 4 shows a perspective view of a pressure piece, Figure 5 shows a hot runner nozzle with a separately screwed-on attachment and Figure 6 shows a hot runner nozzle with an insulation area made of an insulation body according to the invention. Figure 1 shows a perspective view of a hot runner manifold body 13, on which several hot runner nozzles 16 are accommodated by means of nozzle heads 15. Furthermore, several pressure pieces 12 are located on the hot runner manifold body 13 in order to arrange the hot runner manifold body 13 between two tool bodies, as in the further Figure 2 shown. The hot runner manifold body 13 has melt channels 21 on the inside, which continue into a nozzle channel 22 in the hot runner nozzles 16. Figure 2shows a cross-sectional view of the hot runner manifold body 13 between two tool bodies 14, and on one side, a hot runner nozzle 16 is received on the hot runner manifold body 13 by means of a nozzle head 15. On the opposite side, a pressure piece 12 is arranged on the hot runner manifold body 13. The pressure piece 12 supports the hot runner manifold body 13 against a tool body 14 in the form of a clamping plate 19, and the nozzle head 15 is located in a clamping arrangement between the hot runner manifold body 13 and a tool body 14 in the form of a mold plate 20.

[0026] Within the hot runner manifold body 13, the melt channel 21 is shown, which merges into the nozzle channel 22. The plasticized plastic melt can be guided through the melt channel 21 and the nozzle channel 22, since the hot runner manifold body 13 and the hot runner nozzle 16 are maintained at a temperature of, for example, 270°C. In contrast, the tool bodies 14 in the form of the clamping plate 19 and the mold plate 20 have a significantly lower temperature, for example, even only room temperature.

[0027] The illustration shows the pressure piece 12 and the nozzle head 15 with a corresponding heat-insulating geometric structure. The material of the pressure piece 12 and the nozzle head 15 forms an insulating body 1, which, according to the invention, comprises a metal formed directly from a metallic melt and has an amorphous structure. Thus, the insulating body 1 is formed, in particular, from a metallic glass.In particular, due to the arrangement between a very hot first component 10, for example, the hot runner manifold body 13, and a significantly cooler second component 11, for example, the clamping plate 19 or the mold plate 20, the insulating body 1 made of metallic glass results in very low heat transfer, so that the heating power for controlling the temperature in the hot runner manifold body 13 and the hot runner nozzle 16 can be reduced. At the same time, the cooling power of the tool bodies 14 can also be reduced because less heat is input. Cooling channels 23 are shown in the clamping plate 19 and the mold plate 20 for cooling the plates 19 and 20.

[0028] Figure 3shows a perspective view of a nozzle head 15, which is designed according to the invention as an insulating body 1 with the features of the invention. The nozzle head 15 has a threaded area 24 on the inside and is designed approximately sleeve-shaped, so that the hot runner nozzle 16, see Figure 1 , can be introduced into the threaded area 24 and in particular screwed in. The sleeve-shaped nozzle head 15 extends from a lower annular contact surface 25 for contact against the hot hot runner manifold body 13 to a ring contact surface 26 for contact against the cold tool body 14. The nozzle head 15 for forming the insulation body 1 has been manufactured by means of a generative manufacturing process, in particular by means of an SLM process, and has an amorphous metal.

[0029] The nozzle head 15 is traversed by several hollow chambers 27, which extend tubularly between the two contact surfaces 25 and 26 in order to minimize the heat-transferring cross-section with the nozzle head 15 as much as possible. For structural reinforcement of the nozzle head 15, it also has a honeycomb structure 28.

[0030] Figure 4 shows a perspective view of a pressure piece 12 made of an amorphous metal, so that the pressure piece 12, according to this exemplary embodiment, forms the insulating body 1 of the injection molding tool. The pressure piece 12 also has hollow chambers 27 with a honeycomb structure 28, creating a body structure that makes the pressure piece 12 highly mechanically resilient, particularly between the two contact surfaces 29. The hollow chambers 27 form a minimized material cross-section between the two contact surfaces 29, so that heat transfer between the two contact surfaces 29 is minimized in the same way.

[0031] Figure 5 shows a nozzle tip 18 of a hot runner nozzle 16, in which the nozzle channel 22 is formed. An attachment 17 with a thread 30 is screwed onto the nozzle tip 18, and the attachment 17 forms an insulating body 1 made of an amorphous metal. The attachment 17 serves to bear against the mold of the injection molding tool, in which the cavity is also formed, for which contact surfaces 31 are provided. Due to the low thermal conductivity of the insulating body 1 made of an amorphous metal, only minimal heat transfer occurs from the hot hot runner nozzle 16 to the cooler tool (the latter is not shown).

[0032] A further embodiment of a hot runner nozzle 16 shows Figure 6, and at the nozzle tip 18 is a material section 32 that forms the insulating body 1. This material section is formed by the insulating body 1 being part of the one-piece hot runner nozzle 16. However, the insulating body 1 has been applied to a base body made of a different material than the hot runner nozzle 16 using a generative manufacturing process, and the material section 32 consists of an amorphous metal. The material section 32 serves to bear against the mold of the injection molding plant and has at least one contact surface 31.

[0033] The invention is not limited in its implementation to the preferred embodiment described above. Rather, a number of variants are conceivable, which utilize the presented solution even in fundamentally different embodiments. All features and / or advantages apparent from the claims, the description, or the drawings, including structural details or spatial arrangements, may be essential to the invention both individually and in a wide variety of combinations. The invention is defined in the appended set of claims. List of reference symbols:

[0034] 1Insulating body 10First component 11Second component 12Pressure piece 13Hot runner manifold body 14Tool body 15Nozzle head 16Hot runner nozzle 17Attachment 18Nozzle tip 19Clamping plate 20Mold plate 21Melt channel 22Nozzle channel 23Cooling channel 24Thread area 25Ring support surface 26Ring support surface 27Hollow chamber 28Honeycomb structure 29Contact surface 30Thread 31Contact surface 32Material section

Claims

1. An insulating body (1) of an injection molding tool for the thermal insulation of a first component (10) from a second component (11) of the injection molding tool or as an element of a component of the injection molding tool, wherein the insulating body (1) comprises a metal that is formed directly from a metallic melt and has an amorphous structure, characterized in that the insulating body (1) forms a pressure piece (12) for arrangement between a hot runner distributor body (13) and a tool body (14); and / or in that the insulating body (1) forms a nozzle head (15) for mounting a hot runner nozzle (16) on the hot runner distributor body (13); and / or in that the insulating body (1) forms an attachment (17) for arrangement on nozzle tip (18) of a hot runner nozzle (16); and / or in that the insulating body (1) forms an element of a hot runner nozzle (16) formed in one part.

2. An insulating body (1) in accordance with claim 1, characterized in that the insulating body (1) is formed in one part and / or is produced by means of a generative production method.

3. An insulating body (1) in accordance with claim 1, characterized in that the insulating body (1) is applied as an element of the hot runner nozzle (16) formed in one part by means of the generative production method to a base body of a different material of the hot runner nozzle (16).

4. An insulating body (1) in accordance with one of the preceding claims, characterized in that the insulating body (1) comprises a metal comprising the alloy Zr52.5 Ti5 Cu17,9 Ni14,6 Al10; and / or in that the metal for forming the insulating body (1) is based on zirconium.

5. An injection molding tool having an insulating body (1) for the thermal insulation of a first element (10) from a second element (11) of the injection molding tool, wherein the insulating body (1) comprises a metal that is formed directly from a metallic melt and has an amorphous structure, characterized in that the insulating body (1) forms a pressure piece (12) for arrangement between a hot runner distributor body (13) and a tool body (14); and / or in that the insulating body (1) forms a pressure piece (12) for mounting a hot runner nozzle (16) on the hot runner distributor body (13); and / or in that the insulating body (1) forms an attachment (17) for arrangement on a nozzle tip (18) of a hot runner nozzle (16); and / or in that the insulating body (1) forms an element of a hot runner nozzle (16) formed in one part.

6. An injection molding tool in accordance with claim 5, characterized in that the insulating body (1) is formed in one part and / or is produced by means of a generative production method.

7. An injection molding tool in accordance with claim 5 or claim 6, characterized in that a pressure piece (12) is provided for arrangement between a hot runner distributor body (13) and a tool body (14) that is formed by the insulating body (1).

8. An injection molding tool in accordance with one of the claims 5 to 7, characterized in that that a pressure piece (15) is provided for mounting a hot runner nozzle (16) on the hot runner distributor body (13) that is formed by the insulating body (1).

9. An injection molding tool in accordance with one of the claims 5 to 8, characterized in that a hot runner nozzle (16) is provided for conducting a plasticized plastic melt composed of the hot runner distributor body (13) into a tool, with the insulating body (1) forming an attachment (17) for arrangement at a nozzle tip (18) of the hot runner nozzle (16).

10. An injection molding tool in accordance with one of the claims 5 to 9, characterized in that the insulating body (1) forms an element of a hot runner nozzle (16) formed in one part.

11. An injection molding tool in accordance with one of the claims 5 to 10, characterized in that the insulating body (1) is applied as an element of the hot runner nozzle (16) formed in one part by means of the generative production method to a base body of a different material of the hot runner nozzle (16).