Non-contact valve needle glue feeding runner structure

Abstract

The present application belongs to the technical field of injection molding, and discloses a non-contact valve needle glue feeding runner structure, which comprises a heating seat, a glue injection hole, a glue injection cavity and a valve needle, wherein the glue injection hole and the glue injection cavity are arranged in the heating seat, the glue injection hole is communicated with the glue injection cavity, a runner separator is arranged in the heating seat, the runner separator is at least partially arranged in the glue injection cavity, at least one runner for the flow of hot molten glue is formed between the runner separator and the glue injection cavity, a valve needle hole is arranged in the runner separator to separate the glue injection cavity and the valve needle, and the heating seat is at least partially tightly combined with the runner separator to enable the heating seat to perform heat transfer on the runner separator. The present application solves the problem of the insufficient improvement of the hot runner structure for the PET plastic injection molding products with a temperature of 280 DEG C or above in the prior art, which leads to the stress line when the valve needle is sealed and contacts the molten glue of the hot runner, and the high waste rate.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of injection molding, and particularly relates to a non-contact valve needle glue feeding runner structure. BACKGROUND

[0002] During the injection molding process of an injection molding machine, the heated PET plastic in a molten state (temperature about 280 degrees) is blocked and divided by a valve needle before entering a heating seat. Since the temperature of the valve needle is about 100 degrees, the low-temperature PET will crystallize, become white, and harden. When the cold material contacting the valve needle enters the mold cavity together, the product will have stress lines, which will affect the appearance quality. When the bottle is blown, there will be one or more stress lines on the bottle body, which will affect the appearance quality and reduce the qualified rate.

[0003] In order to solve the above problems, a valve needle combined hot runner structure is disclosed in Chinese patent 202123132512.8, which comprises a valve needle assembly, the valve needle assembly comprises a valve needle sleeve and an inner valve needle which is in contact with the mold gate.

[0004] The above-mentioned patent isolates the temperature conduction of the molten glue through the valve needle sleeve to the inner valve needle. The inner valve needle is connected to a cooling system, which effectively controls the temperature of the glue gate end face of the valve needle, solves the problem of crystallization and whitening of the product surface position where the valve needle gate contacts, and forms a controllable injection molding structure of the glue gate end face of the valve needle.

[0005] However, the above-mentioned patent has two hidden dangers in the use process:

[0006] First, since the valve needle sleeve is directly in contact with the molten glue in the runner, and the temperature of the valve needle sleeve itself is not high, part of the glue will be blocked by the cold when it first contacts the valve needle sleeve, resulting in stratification and stress lines. Until the temperature of the heat transfer of the valve needle sleeve rises to be basically the same as the temperature of the molten glue; that is, the quality of the injection molded product at the beginning stage will decrease, and the scrap rate will increase.

[0007] Second, the above-mentioned patent is suitable for PET material injection molding process of 120-220℃, and for PET plastic injection molding process of 280℃ and above, since the temperature difference between the valve needle and the molten glue is too high, the part of the valve needle which contacts the runner during needle sealing needs to have a certain high temperature to avoid the generation of stress lines. When the hot runner structure of the above-mentioned patent is used for PET plastic injection molding structure of 280℃ and above, the inner valve needle does not participate in heat transfer. When the inner valve needle seals the injection, since the temperature difference between the inner valve needle and the molten glue is too large, the glue will have a large number of stress lines.

[0008] Therefore, it is necessary to design a hot runner structure for PET plastic injection molding products of 280℃ and above, to reduce the generation of stress lines of the product and improve the quality of the product. SUMMARY

[0009] The present application aims to provide a non-contact valve needle glue feeding runner structure to solve the problem of insufficient improvement of hot runner structure for PET plastic injection molding products at 280℃ and above in the prior art, which causes stress lines when the valve needle is sealed and contacts the molten glue of the hot runner, resulting in a high waste rate.

[0010] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0011] A non-contact valve needle glue feeding runner structure, comprising a heating seat, a glue injection hole, a glue injection cavity and a valve needle, the glue injection hole and the glue injection cavity are arranged in the heating seat, the glue injection hole is in communication with the glue injection cavity, a flow channel separator is arranged in the heating seat, the flow channel separator is at least partially arranged in the glue injection cavity, at least one flow channel for the flow of hot molten glue is formed between the flow channel separator and the glue injection cavity, a valve needle hole is arranged in the flow channel separator to separate the glue injection cavity and the valve needle; the heating seat is at least partially tightly attached to the flow channel separator so that the heating seat can conduct heat to the flow channel separator.

[0012] The number of flow channels for the flow of hot molten glue formed between the flow channel separator and the glue injection cavity is preferably one, two, three or four.

[0013] In the above-mentioned non-contact valve needle glue feeding runner structure, one or more flow channel grooves are arranged on the outer wall of the flow channel separator, and the flow channel is formed between the flow channel grooves and the glue injection cavity.

[0014] Preferably, the number of flow channel grooves is one, two, three or four.

[0015] Further, when the number of flow channel grooves is one, the horizontal cross-sectional area of the flow channel groove is ≥48mm 2 ; when the number of flow channel grooves is two or more, the sum of the horizontal cross-sectional areas of the flow channel grooves is ≥48mm 2 .

[0016] More preferably, the number of flow channel grooves is three, the length of the flow channel groove is 50-60mm, the depth is 3-5mm, and the width is 8-12mm.

[0017] Most preferably, the number of flow channel grooves is one, the length of the flow channel groove is 50-60mm, the depth is 4-7mm, and the width is 12-15mm.

[0018] In the above-mentioned non-contact valve needle glue feeding runner structure, when the flow channel groove is one, one end of the flow channel is in communication with the glue injection hole, and the other end of the flow channel is in communication with the end of the valve needle hole.

[0019] In the non-contact valve needle glue feeding flow channel structure, when the flow channel groove is multiple, the outer wall of the flow channel separator is further provided with a flow channel groove, one end of the flow channel groove is communicated with the flow channel groove, and the other end of the flow channel groove is communicated with the end of the valve needle hole.

[0020] In the non-contact valve needle glue feeding flow channel structure, the top end of the flow channel separator is provided with a positioning block, and the top end of the heating seat is provided with a positioning groove matched with the positioning block.

[0021] In the non-contact valve needle glue feeding flow channel structure, the end of the flow channel separator is closely matched with the end of the glue injection cavity, the end of the flow channel groove is provided with a flow channel hole communicated with the end of the valve needle hole, and when in the glue injection state, the valve needle is above the flow channel hole.

[0022] Further, the non-contact valve needle glue feeding flow channel structure further comprises a piston, a power output end of the piston is fixedly connected with the valve needle, the piston is used for driving the valve needle to ascend or descend in the valve needle hole, the end of the glue injection cavity is provided with an injection port for communicating with an external injection mold, when the valve needle is above the injection port, the hot melt glue flows into the injection port from the flow channel, and when the valve needle descends and is inserted into the injection port, the hot melt glue stays in the flow channel.

[0023] In the non-contact valve needle glue feeding flow channel structure, the outer wall of the valve needle is closely matched with the inner wall of the valve needle hole.

[0024] Compared with the prior art, the non-contact valve needle glue feeding flow channel structure has the following effects:

[0025] I. The flow channel and the valve needle are separated by the flow channel separator, so that the molten PET plastic does not contact the valve needle during the whole injection process, the valve needle in the low-temperature state is avoided, there is no temperature difference in the whole injection process, no cold material appears, and finally the product does not have a stress line;

[0026] II. The heating seat and the flow channel separator are closely contacted, so that the heating seat heats the flow channel separator, the flow channel separator has a certain high temperature, and the molten glue does not encounter cold to generate crystallization, whitening, caking and hardening when contacting the flow channel separator, thereby reducing the product scrap rate;

[0027] III. The valve needle in a part of position is heated by the heat conduction of the flow channel separator, the temperature of the part of the valve needle in contact with the flow channel during needle sealing is improved, the phenomenon that the molten glue and the valve needle have a large temperature difference and the PET low temperature crystallizes, whitens, caking and hardens is avoided to a certain extent, and the product quality is improved;

[0028] Four, the structure design of the runner separator makes the flow of the molten gel not blocked, and the stress line caused by layering is avoided, and the product quality is improved. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is a perspective view of the present application;

[0030] Figure 2 is a front view of the present application;

[0031] Figure 3 is a sectional view of A-A section of Figure 2

[0032] Figure 4 is a left view of the present application;

[0033] Figure 5 is a sectional view of B-B section of Figure 4

[0034] Figure 6 is a front view of the heating seat of the present application;

[0035] Figure 7 is a sectional view of C-C section of Figure 6

[0036] Figure 8 is a perspective view of the runner separator of Example 1 of the present application;

[0037] Figure 9 is a front view of the runner separator of Example 1 of the present application;

[0038] Figure 10 is a sectional view of D-D section of Figure 9

[0039] Figure 11 is a right view of the runner separator of the present application;

[0040] Figure 12 is a perspective view of the runner separator of Example 2 of the present application;

[0041] Figure 13 is a front view of the runner separator of Example 2 of the present application;

[0042] Figure 14 is a sectional view of E-E section of Figure 13

[0043] Figure 15 is a picture of product waste with stress line;

[0044] Figure 16 is a picture of product without stress line.

[0045] ​​​​​Fig. 1, heating seat, 2, glue injection hole, 3, glue injection cavity, 4, valve needle, 5, flow channel separator, 6, flow channel groove, 7, mold, 8, flow channel groove, 9, positioning block, 10, flow channel hole, 11, valve needle hole, 12, piston, 13, injection port. DETAILED DESCRIPTION

[0046] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0047] Embodiment 1

[0048] Please refer to Figures 1-11 , Figure 15 and Figure 16 , the present application provides a technical solution: a non-contact valve needle 4 glue injection flow channel structure, comprising a heating seat 1, a glue injection hole 2, a glue injection cavity 3 and a valve needle 4, the glue injection hole 2 and the glue injection cavity 3 are arranged in the heating seat 1, the glue injection hole 2 is communicated with the glue injection cavity 3, the heating seat 1 is provided with a flow channel separator 5, the flow channel separator 5 is at least partially arranged in the glue injection cavity 3, the flow channel separator 5 and the glue injection cavity 3 form at least one flow channel for the flow of hot melt glue, the inside of the flow channel separator 5 is provided with a valve needle hole 11 for the valve needle 4 to pass through, so as to separate the glue injection cavity 3 and the valve needle 4; the heating seat 1 is at least partially tightly combined with the flow channel separator 5, so that the heating seat 1 can heat the flow channel separator 5.

[0049] The flow channel separator 5 provided in the embodiment effectively avoids the direct contact of the high-temperature hot melt glue in the flow channel with the valve needle 4 with low temperature, avoids the emergence of cold material to cause the generation of stress line of injection molded product; the flow channel separator 5 receives the heating of the heating seat 1 during the entire injection molding process, can be maintained in a suitable temperature range, so that the hot melt glue maintains smooth flow during the entire flow channel flow process;

[0050] And for the injection molding of products at 280℃ and above, the flow channel separator 5 can heat part of the position of the valve needle 4, so that the temperature of part of the position of the valve needle 4 is maintained at 200℃-280℃ due to the heat transfer of the flow channel separator 5, and there is no great temperature difference between the hot melt glue, the probability of PET crystallization, whitening, caking and hardening is reduced, and the product quality is effectively improved.

[0051] See Figure 15 and Figure 16 , Figure 15The arrow mark inside the product is the stress line of the product. The generation of the stress line has a significant impact on the quality of the product.

[0052] In practical application, the heating seat 1 heats the glue injection hole 2, the heating cavity and the flow channel partition 5, so that the hot melt glue maintains a certain temperature during flowing into the mold 7. The hot melt glue will not flow unsmoothly due to temperature difference, and will not produce cold material, which affects the quality of injection molding product and causes stress line of the product.

[0053] The mold is external and is not within the scope of the present application.

[0054] In the embodiment, a plurality of flow channel grooves 6 are arranged on the outer wall of the flow channel partition 5, and the flow channel grooves 6 and the glue injection cavity 3 form the flow channel.

[0055] Preferably, the number of the flow channel grooves 6 is three.

[0056] More preferably, the length of the flow channel groove 6 is 50-60 mm, the depth is 3-5 mm, and the width is 8-12 mm.

[0057] In addition, the sum of the horizontal cross-sectional areas of the three flow channel grooves 6 is ≥48 mm 2 .

[0058] In the embodiment, the length of the flow channel groove 6 is 50 mm, the depth is 3 mm, and the width is 8 mm.

[0059] In the actual injection molding process, the hot melt glue enters the flow channel formed between the flow channel groove 6 and the glue cavity from the glue injection hole 2, and the hot melt glue enters the mold 7 along the flow channel.

[0060] Further, the outer wall of the flow channel partition 5 is also annularly provided with a flow groove 8, one end of the three flow channel grooves 6 communicates with the flow groove 8, and the other end of the flow channel groove 6 communicates with the end of the valve needle 4 hole.

[0061] In practical application, since the glue injection hole 2 is only one, it is necessary to set a flow groove 8 to divide the hot melt glue into each flow channel groove 6. The hot melt glue enters the flow groove 8 from the glue injection hole 2, and then is divided into the flow channel groove 6 connected with the flow groove 8.

[0062] In order to ensure that the flow channel partition 5 will not be displaced during use to cause the flow channel position to change and affect the flow rate and output rate of the hot melt glue, the top end of the flow channel partition 5 is provided with a positioning block 9, and the top end of the heating seat 1 is provided with a positioning groove matched with the positioning block 9. The flow channel partition 5 is positioned and fixed in the heating seat 1 by the cooperation of the positioning block 9 and the positioning groove.

[0063] In the embodiment, the end of the flow channel partition 5 is tightly matched with the end of the glue injection cavity 3, and the end of the flow channel groove 6 is provided with a flow channel hole 10 and the end of the valve needle hole 11 is communicated; when in the glue injection state, the valve needle 4 is above the flow channel hole 10.

[0064] In actual application, the end of the flow channel partition 5 is tightly matched with the end of the glue injection cavity 3 to form a seal, and then the hot melt glue body enters the flow channel hole 10 from the flow channel, enters the valve needle hole 11, and is injected into the mold 7 from the valve needle hole 11.

[0065] Further, the glue injection split flow channel structure of the non-contact valve needle 4 further comprises a piston 12, a power output end of the piston 12 is fixedly connected with the valve needle 4, and the piston 12 is used for driving the valve needle 4 to ascend or descend in the valve needle 4 hole; the end of the glue injection cavity 3 is provided with an injection port 13 for communicating with an external injection mold 7; when the valve needle 4 is above the injection port 13, the hot melt glue body flows into the injection port 13 from the flow channel; when the valve needle 4 descends and is inserted into the injection port 13, the hot melt glue body stays in the flow channel.

[0066] In the embodiment, the outer wall of the valve needle 4 is tightly matched with the inner wall of the valve needle 4 hole, and the purpose is to make the flow channel partition 5 fully contact with a part of the valve needle 4, and improve the heat transfer efficiency of the flow channel partition 5.

[0067] Embodiment 2

[0068] Please refer to Figures 1-7 , Figures 11-16 The application provides a technical scheme: a glue injection split flow channel structure of a non-contact valve needle 4, comprising a heating seat 1, a glue injection hole 2, a glue injection cavity 3 and a valve needle 4, the glue injection hole 2 and the glue injection cavity 3 are arranged in the heating seat 1, the glue injection hole 2 is communicated with the glue injection cavity 3, the heating seat 1 is provided with a flow channel partition 5, the flow channel partition 5 is at least partially arranged in the glue injection cavity 3, the flow channel partition 5 and the glue injection cavity 3 form at least one flow channel for the hot melt glue body to flow, the inside of the flow channel partition 5 is provided with a valve needle hole 11 for the valve needle 4 to pass through, so as to separate the glue injection cavity 3 and the valve needle 4; the heating seat 1 is at least partially tightly matched with the flow channel partition 5, so that the heating seat 1 can perform heat transfer on the flow channel partition 5.

[0069] The flow channel partition 5 arranged in the embodiment can effectively avoid the direct contact between the high-temperature hot melt glue body in the flow channel and the valve needle 4 with a low temperature, and can avoid the emergence of cold material to cause the generation of stress lines of the injection molding product; the flow channel partition 5 receives the heating of the heating seat 1 in the whole injection molding process, can be maintained in a suitable temperature range, and can make the hot melt glue body maintain smooth flow in the whole flow channel flow process;

[0070] And for the product injection molding of 280℃ and above, the runner partition 5 can transfer heat to part of the position of the valve needle 4, so that the temperature of the part of the position of the valve needle 4 is maintained at 200℃-280℃ due to the heat transfer of the runner partition 5, and there is no large temperature difference between the hot melt glue, the probability of PET crystallization, whitening, caking and hardening is reduced, and the product quality is effectively improved.

[0071] See Figure 15 And Figure 16 , Figure 15 The arrow mark in the figure is the stress line of the product, and the generation of the stress line has a significant impact on the quality of the product.

[0072] In actual application, the heating seat 1 heats the glue injection hole 2, the heating cavity and the runner partition 5, so that the entire hot melt glue maintains a certain temperature during flowing into the mold 7, and the hot melt glue will not flow smoothly due to temperature difference, cold material will not be generated, and other factors will affect the quality of injection molding products, and quality problems such as stress lines of products will not occur.

[0073] In this embodiment, a runner groove 6 is arranged on the outer wall of the runner partition 5, and the runner groove 6 and the glue injection cavity 3 form the runner.

[0074] More preferably, the length of the runner groove 6 is 50-60mm, the depth is 4-7mm, and the width is 12-15mm.

[0075] Moreover, the horizontal cross-sectional area of the runner groove 6 is ≥48mm2.

[0076] In this embodiment, the length of the runner groove 6 is 50mm, the depth is 4mm, and the width is 12mm.

[0077] In this embodiment, one end of the runner communicates with the glue injection hole 2, and the other end of the runner communicates with the end of the valve needle 4 hole.

[0078] Further, the end of the runner partition 5 is tightly matched with the end of the glue injection cavity 3, and the end of the runner groove 6 is provided with a runner hole 10 and a valve needle hole 11 which communicate with the end of the valve needle hole 11; when in the glue injection state, the valve needle 4 is above the runner hole 10.

[0079] In actual application, the end of the runner partition 5 is tightly matched with the end of the glue injection cavity 3 to form a seal, then the hot melt glue enters the runner hole 10 from the runner, enters the valve needle hole 11, and is injected into the mold 7 from the valve needle 4 hole.

[0080] Compared with the three runner grooves 6 of embodiment 1, one runner groove 6 has more advantages, and the reason is that:

[0081] Since the hot melt adhesive finally flows into the mold 7 from the flow channel through the valve needle 4 hole, the final flow rate is mainly determined by the size of the valve needle 4 hole, and since the valve needle 4 hole is small, the three flow channels formed by the three flow channel grooves 6 will have a flow rate reduction phenomenon due to the convergence of the three flow channels when they finally converge into the valve needle 4 hole, and the stress lines will be generated due to the blocking of the hot melt adhesive, which will affect the product quality; therefore, one flow channel groove 6 directly enters the valve needle 4 hole, which can reduce the blocking effect caused by the convergence of the three flow channels, so that the product quality is better.

[0082] The non-contact valve needle 4 glue feeding flow channel structure further comprises a piston 12, the power output end of the piston 12 is fixedly connected with the valve needle 4, and the piston 12 is used for driving the valve needle 4 to ascend or descend in the valve needle 4 hole; the end of the glue injection cavity 3 is provided with an injection port 13 for connecting an injection mold 7 of an external device; when the valve needle 4 is above the injection port 13, the hot melt adhesive flows from the flow channel into the injection port 13; when the valve needle 4 descends and inserts into the injection port 13, the hot melt adhesive stays in the flow channel.

[0083] Similarly, in order to ensure that the flow channel divider 5 does not displace during use and cause the flow channel position to change, affecting the flow rate and output rate of the hot melt adhesive, the top end of the flow channel divider 5 is provided with a positioning block 9, and the top end of the heating seat 1 is provided with a positioning groove matched with the positioning block 9, and the flow channel divider 5 is positioned and fixed in the heating seat 1 through the cooperation of the positioning block 9 and the positioning groove.

[0084] In the embodiment, the outer wall of the valve needle 4 is tightly fitted with the inner wall of the valve needle 4 hole, which aims to make the flow channel divider 5 fully contact with a part of the valve needle 4, and improve the heat transfer efficiency of the flow channel divider 5.

[0085] Although the embodiments of the present application have been shown and described, it can be understood by those skilled in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A non-contact valve needle glue feeding runner structure, comprising a heating seat, a glue injection hole, a glue injection cavity and a valve needle, the glue injection hole and the glue injection cavity are arranged in the heating seat, the glue injection hole is communicated with the glue injection cavity, characterized in that, The heating seat is provided with a flow channel partition, which is at least partially arranged in the glue injection cavity, and at least one flow channel for the hot melt glue to flow is formed between the flow channel partition and the glue injection cavity. The flow channel partition is provided with a valve needle hole for the valve needle to pass through, so as to separate the glue injection cavity and the valve needle. The heating seat is at least partially tightly combined with the flow channel partition, so that the heating seat can heat the flow channel partition. The outer wall of the flow channel partition is provided with one or more flow channel grooves, and the flow channel grooves and the glue injection cavity form the flow channel. The end of the flow channel partition is tightly combined with the end of the glue injection cavity, and the end of the flow channel groove is provided with a flow channel hole which is in communication with the end of the valve needle hole. When in the glue injection state, the valve needle is above the flow channel hole. The outer wall of the valve needle is tightly combined with the inner wall of the valve needle hole.

2. The touchless valve pin metering manifold structure of claim 1, wherein, When the flow channel groove is one, one end of the flow channel is in communication with the glue injection hole, and the other end of the flow channel is in communication with the end of the valve needle hole.

3. The touchless valve pin transfer gate structure of claim 2, wherein, The horizontal cross-sectional area of the flow channel groove is ≥ 48 mm 2 .

4. The touchless valve pin-transfer gate structure of claim 1, wherein, When the flow channel groove is multiple, the outer wall of the flow channel partition is further provided with a circulation groove, one end of the flow channel groove is in communication with the circulation groove, and the other end of the flow channel groove is in communication with the end of the valve needle hole.

5. The touchless valve pin transfer gate structure of claim 4, wherein, The sum of the horizontal cross-sectional areas of the plurality of flow channel grooves is ≥ 48 mm 2 .

6. The non-contact valve pin transfer gate structure of any of claims 1-5, wherein, The top end of the flow channel partition is provided with a positioning block, and the top end of the heating seat is provided with a positioning groove matched with the positioning block.

7. The touchless valve pin-transfer gate structure of claim 1, wherein Further comprising a piston, the power output end of the piston is fixedly connected with the valve needle, and the piston is used for driving the valve needle to ascend or descend in the valve needle hole. The end of the glue injection cavity is provided with an injection port for communicating with an external injection mold. When the valve needle is above the injection port, the hot melt glue flows into the injection port from the flow channel. When the valve needle descends and is inserted into the injection port, the hot melt glue stays in the flow channel.

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