Nozzle insert and nozzle for injection mold

Abstract

The present invention relates to a nozzle insert and a nozzle for an injection mold wherein the nozzle insert (100) comprises a feed duct portion (101) extending within the nozzle insert (100), a plurality of nozzle tips (103) and a plurality of secondary runners (105) wherein each secondary runner (105) of the plurality of secondary runners (105) is connected in fluid communication to the feed duct portion (101) wherein the nozzle tips (103) are arranged in the feed duct portion (101). Each secondary flow channel (105) of the plurality of secondary flow channels (105) is configured to discharge the flowable substance supplied through the feed conduit portion (101) from a respective nozzle tip (103) of the plurality of nozzle tips (103).

Description

Technical Field

[0001] The invention relates to a nozzle insert and a nozzle for an injection mold, as well as an injection mold and a manufacturing method. Background Art

[0002] Nozzle and nozzle insert for injection molding system are disclosed by DE102010013859A1 for example.Therefore, nozzle is made up of material pipe and nozzle insert, and they are configured together like this, that is, flowable plastic material is supplied to separable mold piece (mold nest) under predetermined temperature and relatively high pressure.

[0003] The first end of the material pipe is usually connected to the distributor, while the second end opposite the first end is located in the so-called antechamber area opposite the gate. In order to prevent the plastic material from cooling prematurely in the antechamber, a nozzle insert with a plurality of nozzle tips is formed at the second end of the material pipe. The nozzle tips are formed conically and are guided to the respective gate for the injection molding process.

[0004] For the parallel injection molding of a plurality of articles, multi-cavity molds are known which comprise a plurality of cavities, each of which forms a respective article, wherein each cavity is usually supplied with flowable material via its own gate and nozzle tip.

[0005] In particular, when using nozzles with multiple nozzle tips and control circuits, uneven material flow may occur, which may lead to, for example, streaks and filling differences and / or blockages in the antechamber area. Such phenomena may render the item unusable and result in more waste. Summary of the invention

[0006] Against this background, the object of the present invention is to minimize the amount of waste when manufacturing articles using injection molds, in particular multi-cavity molds.

[0007] According to a first aspect of the present invention, therefore, a nozzle insert for an injection mold is proposed.

[0008] The proposed nozzle insert includes a feed conduit portion extending in the nozzle insert, a plurality of nozzle tips, and a plurality of secondary flow channels, wherein each of the plurality of secondary flow channels is fluidically connected to the feed conduit portion, and wherein each of the plurality of secondary flow channels is configured to discharge a flowable substance supplied through the feed conduit portion from each of the plurality of nozzle tips.

[0009] The proposed invention is based on a nozzle insert, ie a component which is provided for connection to a material pipe.

[0010] The nozzle insert comprises a plurality of channels, which are provided, for example, by drilling. Alternatively, the proposed nozzle insert can also be manufactured in an additive manufacturing process such as 3D printing, wherein the channels are left out so that the material forming the nozzle insert is formed around the channels.

[0011] The channel formed in the nozzle insert is configured to convey a flowable substance and includes a feed conduit portion supplied with the flowable substance from a supply source in operation and a plurality of side channels supplied with the flowable substance from the feed conduit portion in operation. Accordingly, the feed conduit portion opens into the side channels or is fluidly connected with the side channels.

[0012] For fluidic connection of the feed line section with the respective secondary channel, the secondary channel can be inserted into the feed line section, for example one after the other in the flow direction. Alternatively or additionally, the feed line section can open into a storage container, into one of the selected secondary channels or into all of the secondary channels. In this case, the storage container can have a larger volume or a larger cross-section than the feed line section, so that the storage container acts as a buffer, which evens out the material flow through the nozzle insert.

[0013] The fluid-communicating connection of the feed line section to the secondary flow channel ensures that the substance flowing through the feed line section does not flow through the feed line section itself and accordingly does not flow out of the central opening of the nozzle insert as is customary in the prior art.

[0014] In contrast, the proposed nozzle insert does not have a central opening, but rather a plurality of openings formed at the respective nozzle tip, so that the flowable substance is distributed to the respective secondary flow channels of the nozzle insert and flows out of the nozzle insert at a plurality of different points.

[0015] In experiments, it was surprisingly found that the use of a nozzle insert with a plurality of openings results in a particularly uniform material flow of the flowable mass out of the nozzle insert, which in particular minimizes the formation of blockages in the antechamber. It was also found that the proposed nozzle insert minimizes streak formation and promotes uniform forming of the objects in the respective mold. Furthermore, filling differences between the respective objects in a multi-cavity mold are effectively avoided.

[0016] It may be provided that each of the plurality of secondary flow channels extends through a respective nozzle tip of the plurality of nozzle tips.

[0017] The flowable substance flows out of the nozzle tip or drips at the nozzle tip via the corresponding secondary flow channel extending through the respective nozzle tip, so that the substance is supplied with heat energy from the nozzle insert and remains hot accordingly before reaching the outermost edge of the nozzle insert.

[0018] It may also be provided that at least one of the plurality of secondary flow channels is configured to discharge the flowable substance from a side surface of a respective nozzle tip of the plurality of nozzle tips.

[0019] The flowable material flows out at one side of the respective nozzle tip, in particular at the outer surface of the respective nozzle tip, causing the material to flow through the path between the nozzle tip and the antechamber or the mold wall. Accordingly, the material flow is guided through a path with a very small cross section at a correspondingly high pressure or high speed. This determines that there are high shear forces in the material. The shear forces in the material prevent the formation of inhomogeneities or agglomerations, such as plugs, and mix or turn over the flowable material itself.

[0020] It can also be provided that the side surfaces of some of the nozzle tips of the plurality of nozzle tips lie on a cylindrical surface which is oriented concentrically with the central axis of the nozzle insert.

[0021] The concentric arrangement of the nozzle tip side surfaces allows very simple supply of the secondary flow channel with flowable material via a central supply region or, in the case of a cylinder, a central supply region.

[0022] It can also be provided that side surfaces of some of the plurality of nozzle tips at least partially have a contour in the axial direction of the central axis.

[0023] The profile can minimize the distance between the nozzle tip or nozzle insert and the respective gate, such as a conical shape, a stepped outer diameter, etc. Here, the profile can be designed correspondingly to the direction of the recess forming the gate, for example.

[0024] It can also be provided that some of the plurality of secondary flow channels are designed to be of the same length.

[0025] The uniform length of the secondary flow channels ensures a uniform material flow from the nozzle insert, so that, for example, several identical objects can be molded in parallel at the same production rhythm.

[0026] It can also be provided that some of the plurality of secondary flow channels are designed to have different lengths.

[0027] Secondary flow channels of different lengths allow different material flows from the nozzle insert, so that, for example, one nozzle tip discharges material before another nozzle tip of the nozzle insert, and, for example, different objects can be formed in the same process.

[0028] It can also be provided that some of the plurality of secondary flow channels extend symmetrically with respect to a central axis of the nozzle insert.

[0029] The secondary flow channels extending symmetrically with respect to the central axis of the nozzle insert ensure a symmetrical flow of the material through the nozzle insert, so that symmetrical molding of a plurality of, in particular identical, objects can be achieved.

[0030] Alternatively, it can be provided that some of the plurality of secondary flow channels extend asymmetrically with respect to a central axis of the nozzle insert.

[0031] The secondary flow channel extending asymmetrically with respect to the nozzle insert central axis allows material to flow asymmetrically through the nozzle insert, so the asymmetrical molding of several especially different articles can be realized. Here, each secondary flow channel can be different from each other for example in its direction or shape, especially in its curvature.

[0032] It can also be provided that the cross sections of some of the plurality of secondary flow channels are different from one another.

[0033] The different cross-sections of the respective secondary flow channels determine different volume flows of the flowable material flowing through the different secondary flow channels, so that, for example, different objects can be formed simultaneously.

[0034] It can also be provided that some of the plurality of secondary flow channels extend at an acute angle to a central axis of the nozzle insert.

[0035] The acute angle of the respective secondary flow channel relative to the central axis of the nozzle insert results in a very uniform material flow, since the pressure acting in the feed section can be transferred into the respective secondary flow channel.

[0036] It can also be provided that the nozzle insert comprises a first seal which is configured to seal the nozzle insert relative to the material pipe in a radial direction of a center axis of the nozzle insert.

[0037] The first seal can be arranged, for example, at the upper end of the nozzle insert, so that the first seal prevents the flowable substance from escaping into the intermediate region between the respective material pipe and the nozzle insert.

[0038] It can also be provided that the nozzle insert comprises a second seal which is configured to seal the nozzle insert in an axial direction relative to the material pipe in the central axis.

[0039] The second seal can, for example, seal an axially extending surface.

[0040] It can also be provided that the nozzle insert comprises at least two nozzle tips and at least two secondary flow channels.

[0041] In particular, a pair of secondary flow channels or secondary flow channels arranged opposite each other in the respective nozzle tip have proven to be particularly suitable for preventing an uneven material flow.

[0042] It can also be provided that the nozzle insert consists of a material with high thermal conductivity.

[0043] The proposed nozzle insert can be made of a highly thermally conductive material such as bronze, copper, aluminum or steel.

[0044] Highly thermally conductive materials, in particular materials with a thermal conductivity λ greater than 100, ensure very efficient heat transfer from the nozzle insert to the substance flowing through the nozzle insert and along the respective nozzle tip, so that the substance remains at a predetermined temperature for a very long time.

[0045] According to a second aspect, the invention relates to a nozzle for an injection mould.

[0046] The proposed nozzle includes a material pipe, a feed conduit extending through the material pipe for receiving a flowing substance from a supply source, and one possible design of the proposed nozzle insert.

[0047] Due to the proposed nozzle insert, the proposed nozzle allows a particularly uniform material flow.

[0048] It can be provided that the nozzle insert and the material pipe form a single piece.

[0049] The one-piece nozzle determines that heat flows through the nozzle very evenly, so the material flowing through the nozzle is evenly heated.

[0050] It can also be provided that the nozzle insert and the material pipe are connected via a connecting interface.

[0051] A connection interface such as a thread or a mechanical locking mechanism allows the nozzle insert to be replaced, so that the material tube can remain in the injection mold when a different nozzle insert is required.

[0052] It can also be provided that the nozzle insert forms a neck in the region of the connecting interface which is surrounded by the material pipe.

[0053] The neck of the nozzle insert, which is surrounded by the material pipe, ensures a high transfer of thermal energy from the material pipe to the nozzle insert and correspondingly to a particularly uniform material flow through the nozzle insert.

[0054] It can also be provided that the material pipe forms a neck in the region of the connecting interface which is surrounded by the nozzle insert.

[0055] Furthermore, the neck of the material pipe surrounded by the nozzle insert ensures a high heat transfer from the material pipe into the nozzle insert and correspondingly to a particularly uniform material flow through the nozzle insert.

[0056] It can also be provided that the material pipe and the nozzle insert bear flat against one another in the region of the connecting interface.

[0057] The flat contact surface between the material pipe and the nozzle insert allows for quick and easy separation or replacement of the nozzle insert.

[0058] According to a third aspect, the invention relates to an injection mould for processing a flowable mass.

[0059] The proposed injection molding tool comprises one possible design of the proposed nozzle insert and a mold plate with an antechamber.

[0060] It can be provided that the nozzle tip of the nozzle insert is arranged in the antechamber.

[0061] Since the nozzle tip of the proposed nozzle insert is arranged in the die plate antechamber, the flow geometry of the material flowing out of the secondary flow channel is determined by the shape of the nozzle tip and the shape of the antechamber.

[0062] It can also be provided that a respective one of the plurality of side secondary flow channels of the nozzle insert opens into a path in a side surface of the respective nozzle tip which extends between the respective nozzle tip and the antechamber wall.

[0063] The path extending between the respective nozzle tip and the wall of the respective antechamber generally exhibits a very small cross section and determines correspondingly high shear forces in the material flow flowing through this path, so that agglomerations in the material flow are minimized.

[0064] Furthermore, the path extending between the respective nozzle tip and the wall of the respective antechamber determines the transfer of heat energy from the nozzle tip to the material flowing in the path, so that the material is heated up to the end of the nozzle tip.

[0065] It can also be provided that the injection molding tool comprises a multi-cavity mold.

[0066] A multi-cavity mold in combination with the proposed injection mold allows the parallel production of a large number of, in particular, identical, objects.

[0067] It may also be provided that the injection mold comprises a family tool.

[0068] The open mold in combination with the proposed injection mold allows the parallel production of a plurality of, in particular, identical and possibly different, objects.

[0069] According to a fourth aspect, the proposed invention relates to a production method for producing an object, wherein the object is formed by means of one possible design of the proposed nozzle insert.

[0070] Based on the proposed nozzle insert, the proposed production method provides particularly uniform shaped objects and determines low scrap. BRIEF DESCRIPTION OF THE DRAWINGS

[0071] Further features, details and advantages of the present invention are derived from the following description of an embodiment based on the figures. The figures show:

[0072] Figure 1 shows one possible design of the proposed injection molding system with one possible design of the proposed nozzle and one possible design of the proposed nozzle insert,

[0073] Figure 2 is based on Figure 1 Detail of the nozzle insert,

[0074] Figure 3 is based on Figure 1 Detailed illustration of the nozzle, and

[0075] Figure 4 is based on Figure 3 Detail of the nozzle.

[0076] Reference numerals list

[0077] 100 Nozzle Inserts

[0078] 101 Feed Pipeline Department

[0079] 103 Nozzle Tip

[0080] 105 secondary flow channel

[0081] 107 side

[0082] 109 Path

[0083] 200 Nozzles

[0084] 201 Material Pipe

[0085] 203 Feed Pipe

[0086] 300 Injection Mold

[0087] 301 Template

[0088] 303 front room

[0089] 305 wall

[0090] 307 Arrow

[0091] 309 Arrow

[0092] 311 Seal

[0093] 313 Seal

[0094] M Center axis DETAILED DESCRIPTION

[0095] Figure 1 An injection mold 300 is shown. The injection mold 300 comprises a nozzle 200 and a mold plate 301 forming a front chamber 303.

[0096] The nozzle 200 includes a material pipe 201 , a feed conduit 203 extending through the material pipe 201 , and a nozzle insert 100 .

[0097] The nozzle insert 100 includes a feed conduit portion 101 extending through the nozzle insert 100 , a plurality of nozzle tips 103 , and a plurality of secondary flow channels 105 .

[0098] The respective sub-flow passages 105 are connected in fluid communication with the feed conduit portion 101 and are configured to discharge the flowable substance supplied from the supply source through the feed conduit portion 101 from the respective nozzle tips 103 .

[0099] Figure 2 Show according to Figure 1 Detailed view of the nozzle insert 100. It can be seen here that the secondary flow channels 105 extend symmetrically around the central axis M of the nozzle insert 100 and respectively open into a side surface 107 of each nozzle tip 103, so that the flowable material flows along a path 109 at the side surface 107 of the nozzle tip 103, thereby determining that the flowable material is heated by the thermal energy accumulated in the nozzle insert 100 during the entire journey through the path 109 along the nozzle tip 103.

[0100] Since the path 109 between the nozzle tip 103 and the antechamber wall has a very small cross section, the path 109 determines a large shear force in the material flow flowing through the path 109, thereby preventing agglomeration in the material flow.

[0101] In addition, the path 109 determines the transfer of heat energy from the nozzle tip 103 to the material flowing in the path 109 , so the material is heated until the end of the nozzle tip 103 .

[0102] Figure 3 The nozzle 200 is shown in detail. Here it can be seen that the nozzle insert 100 is detachably connected to the material pipe 201, so that the nozzle insert 100 can be replaced.

[0103] Figure 4 A further detail of the nozzle insert 100 is shown. Here, the position of the thick film heater at the end of the material pipe 201 is indicated by arrow 307 and the position of the temperature sensor is indicated by arrow 309 .

[0104] In addition, optional seals 311 and 313 are provided in Figure 4 is shown in .

[0105] The present invention is not limited to one of the above-described embodiments but can be modified in various ways.

[0106] All features and advantages resulting from the description and the drawings, including construction details, spatial arrangements and method steps, may be essential to the invention both individually and in any combination.

Claims

1. A nozzle insert (100) for an injection mold (300), wherein: The nozzle insert (100) comprises: - a feed conduit portion (101) extending inside the nozzle insert (100), - a plurality of nozzle tips (103), and - a plurality of secondary flow channels (105), Wherein, each of the plurality of secondary flow channels (105) is fluidically connected to the feed pipeline section (101), wherein each of the plurality of secondary flow channels (105) is configured to discharge the flowable material supplied through the feed pipeline section (101) from a corresponding nozzle tip (103) among the plurality of nozzle tips (103).

2. The nozzle insert (100) according to claim 1, characterized in that Each of the plurality of secondary flow channels (105) extends through a corresponding nozzle tip (103) of the plurality of nozzle tips (103).

3. The nozzle insert (100) according to claim 1 or 2, characterized in that At least one of the plurality of secondary flow channels (105) is configured to discharge a flowable substance from a side surface (107) of a corresponding nozzle tip (103) of the plurality of nozzle tips (103).

4. The nozzle insert (100) according to claim 3, characterized in that The side surface (107) of the nozzle tip (103) of the plurality of nozzle tips (103) is located on a cylindrical surface, which is oriented concentrically with respect to a central axis (M) of the nozzle insert (100).

5. The nozzle insert (100) according to claim 3 or 4, characterized in that The side surface (107) of the nozzle tip (103) among the plurality of nozzle tips (103) has a contour at least partially in the axial direction of the central axis (M).

6. The nozzle insert (100) according to any one of the preceding claims, characterized in that The secondary flow channels (105) in the plurality of secondary flow channels (105) are designed to have the same length.

7. The nozzle insert (100) according to any one of the preceding claims, characterized in that The secondary flow channels (105) in the plurality of secondary flow channels (105) are designed to have different lengths.

8. The nozzle insert (100) according to any one of the preceding claims, characterized in that The secondary flow channels (105) of the plurality of secondary flow channels (105) extend symmetrically with respect to the central axis (M) of the nozzle insert (100).

9. The nozzle insert (100) according to any one of the preceding claims, characterized in that A secondary flow channel (105) among the plurality of secondary flow channels (105) extends asymmetrically with respect to the central axis (M) of the nozzle insert (100).

10. The nozzle insert (100) according to any one of the preceding claims, characterized in that The cross sections of the secondary flow channels (105) in the plurality of secondary flow channels (105) are different from each other.

11. The nozzle insert (100) according to any one of the preceding claims, characterized in that A secondary flow channel (105) of the plurality of secondary flow channels (105) extends at an acute angle relative to the central axis (M) of the nozzle insert (100).

12. The nozzle insert (100) according to any one of the preceding claims, characterized in that The nozzle insert (100) comprises a first seal (311) which is configured to seal the nozzle insert (100) relative to a material pipe (201) in a radial direction of a central axis (M) of the nozzle insert (100).

13. The nozzle insert (100) according to claim 12, characterized in that The nozzle insert (100) comprises a second seal (313) configured to seal the nozzle insert (100) relative to the material pipe (201) in an axial direction of the central axis (M).

14. The nozzle insert (100) according to any one of the preceding claims, characterized in that The nozzle insert (100) comprises at least two nozzle tips (103) and at least two secondary flow channels (105).

15. The nozzle insert (100) according to any one of claims 1 to 14, characterized in that The nozzle insert (100) is made of a material with high thermal conductivity.

16. A nozzle (200) for an injection mold (300), wherein: The nozzle (200) comprises: - a material pipe (201), - a feed conduit (203) extending through the material pipe (201) for receiving a flowable substance from a supply source, - A nozzle insert (100) according to any one of claims 1 to 15.

17. The nozzle (200) according to claim 16, characterized in that The nozzle insert (100) and the material pipe (201) are formed in one piece.

18. The nozzle (200) according to claim 17, characterized in that The nozzle insert (100) and the material pipe (201) are connected via a connection interface.

19. The nozzle (200) according to claim 18, characterized in that The nozzle insert (100) forms a neck in the region of the connecting interface which is surrounded by the material pipe (201).

20. The nozzle (200) according to claim 18, characterized in that The material pipe (201) forms a neck in the region of the connection interface which is surrounded by the nozzle insert (100).

21. The nozzle (200) according to claim 18, characterized in that The material pipe (201) and the nozzle insert (100) are located adjacent to each other in the area of ​​the connecting interface.

22. An injection mold (300) for processing a flowable substance, wherein: The injection mold (300) comprises a nozzle insert (100) according to any one of claims 1 to 15 and a mold plate (301) with a front chamber (303).

23. The injection mold (300) according to claim 22, characterized in that: The nozzle tip (103) of the nozzle insert (100) is arranged in the antechamber (303).

24. The injection mold (300) according to claim 21 or 22, characterized in that: A corresponding secondary flow channel (105) of the plurality of secondary flow channels (105) of the nozzle insert (100) opens into a path (109) in a side surface (107) of the corresponding nozzle tip (103), the path extending between the corresponding nozzle tip (103) and a wall (305) of the antechamber (303).

25. The injection mold (300) according to any one of claims 21 to 24, characterized in that: Each nozzle tip (103) of the plurality of nozzle tips (103) of the nozzle insert (100) is assigned to a gate.

26. The injection mold (300) according to any one of claims 21 to 25, characterized in that: The injection mold (300) comprises a multi-cavity mold.

27. The injection mold (300) according to any one of claims 21 to 26, characterized in that: The injection mold (300) comprises an open mold.

28. A method for manufacturing an article, wherein: An object is formed by means of a nozzle insert (100) according to any one of claims 1 to 15.

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