Test mold and evaluation method for flash value

Abstract

The present application relates to the technical field of mould, disclose a kind of test mould and overflow edge value evaluation method, test mould includes the mould core component for injection molding, at least two cavities are provided in mould core component, mould core component includes movable mould and fixed mould, the opposite side of movable mould and fixed mould is first parting surface, the opposite side of fixed mould and movable mould is second parting surface, when fixed mould and movable mould adhere, first parting surface and second parting surface abut, the outside of each cavity is equipped with several exhaust groove, exhaust groove can exhaust the gas in cavity to the outside of mould core component, exhaust groove is set on first parting surface and / or second parting surface, the depth of exhaust groove connected with same cavity is same, the depth of exhaust groove connected with different cavities is different.Using the test mould and overflow edge value evaluation method of the technical scheme of the present application, the influencing factors of overflow edge value can be analyzed for different materials, and it is determined how to avoid overflow during injection molding.

Description

Technical Field

[0001] This invention relates to the field of mold technology, and in particular to a test mold and a method for evaluating overflow value. Background Technology

[0002] Currently, flash is a very common defect in plastic and rubber injection molding. The solutions typically involve manual post-processing by the molding plant or minimizing the flash gap by the mold factory. The former is time-consuming and labor-intensive, or requires additional equipment, and cannot remove flash in small structures. The latter, however, is limited by mold structure, product structure, and molding difficulty, and is not always effective. When flash is difficult to resolve or processing costs are too high, the only options are to lower product requirements or restrict mold and product structure design.

[0003] Practice has shown that flash during injection molding is highly correlated with the material. Different categories of materials, or materials within the same category with different modification directions, exhibit varying tendencies and severity of flash under similar process conditions. To eliminate or mitigate flash from the material perspective, it is first necessary to establish a method for evaluating and testing material flash values.

[0004] Certain instruments, such as capillary rheometers, can be used to test and evaluate the ability of molten plastics and rubber to pass through tiny gaps. However, this testing method differs greatly from the actual injection molding process. This is because the temperature, pressure, speed, and other conditions in the instrument testing process are too idealized compared to the actual injection molding process. In reality, these conditions change rapidly during injection molding, ultimately causing the test evaluation to fail and become unusable as a valid reference. Summary of the Invention

[0005] The purpose of this invention is to provide a test mold and a method for evaluating flash value. This test mold and flash value evaluation method can effectively analyze the influencing factors of flash value for different materials, thereby determining how to avoid flash during injection molding.

[0006] To achieve the above objectives, the present invention provides a test mold, including a mold core assembly for injection molding. The mold core assembly has at least two cavities. The mold core assembly includes a moving mold and a fixed mold. The side of the moving mold opposite to the fixed mold is a first parting surface, and the side of the fixed mold opposite to the moving mold is a second parting surface. When the fixed mold and the moving mold are fitted together, the first parting surface abuts against the second parting surface. Each cavity has a plurality of venting grooves on its outer side. The venting grooves can discharge gas in the cavity to the outside of the mold core assembly. The venting grooves are disposed on the first parting surface and / or the second parting surface. Venting grooves connected to the same cavity have the same depth, while venting grooves connected to different cavities have different depths.

[0007] In some embodiments of this application, the dimensions and shapes of each cavity are the same, and the width and length of each exhaust groove are the same.

[0008] In some embodiments of this application, a venting groove is provided outside the venting groove, the venting groove communicates with the outer wall of the mold core assembly, the depth of the venting groove is greater than the depth of the venting groove, one end of the venting groove is connected to the cavity, and the other end of the venting groove is connected to the venting groove.

[0009] In some embodiments of this application, the extension direction of the exhaust groove is referred to as the length direction, and the direction perpendicular to the extension direction of the exhaust groove is referred to as the width direction. The width range of the exhaust groove is 3mm-10mm, and the length of the exhaust groove is 3mm-6mm.

[0010] In some embodiments of this application, the test mold further includes a controller, and each cavity is provided with a temperature sensor and a pressure sensor, both of which are electrically connected to the controller.

[0011] In some embodiments of this application, the moving mold is provided with a main runner and a branch runner connected to each other, the fixed mold is provided with a feed port for molten plastic material to enter, the main runner is located at a position opposite to the feed port, and the main runner is connected to each cavity through the branch runner.

[0012] In some embodiments of this application, the venting grooves on the outer side of the same cavity are spaced apart along the flow direction of the plastic material on the outer side of the cavity.

[0013] In some embodiments of this application, exhaust grooves are provided on both the first parting surface and the second parting surface, and the exhaust grooves provided on the first parting surface and the exhaust grooves provided on the second parting surface do not overlap.

[0014] For the same purpose, the present invention also provides a method for evaluating overflow value, comprising the following steps:

[0015] S1. At least two cavities of the same shape and size are machined on the mold core assembly. Several venting grooves are respectively opened on the parting surface of the mold core assembly. The venting grooves connect the cavity and the outside of the mold core assembly. The venting grooves connected to the same cavity have the same depth, and the venting grooves connected to different cavities have different depths.

[0016] S2. After injection molding, observe the overflow around the solidified material in each cavity using a microscope;

[0017] S3. Input the overflow situation and the depth of the venting channel into the controller. Use the controller to classify, statistically analyze and categorize the overflow situation based on the depth of the venting channel, obtain a graph of the venting channel depth and the overflow situation, and store it in the controller.

[0018] In some embodiments of this application, the step S1 is followed by the following step:

[0019] During injection molding, temperature and pressure sensors installed in the cavity are used to obtain the temperature and pressure in each cavity.

[0020] Temperature and pressure are input into the controller. The controller classifies, statistically analyzes, and categorizes the temperature, pressure, and corresponding overflow conditions during injection molding, and generates a graph of temperature, pressure, and overflow conditions, which is then stored in the controller.

[0021] The present invention provides a test mold and a method for evaluating overflow value. Compared with the prior art, its advantages are as follows:

[0022] The test mold and flash value evaluation method of this invention, by setting multiple cavities and setting venting grooves of a certain depth outside each cavity, allows for the observation of the injection-molded product to determine the relationship between the depth of the venting grooves and the flash value. This enables the measurement of the true flash value of samples from the actual injection molding process, which is closer to the actual production situation and has strong authenticity. Furthermore, by changing the raw materials used in injection molding, the relationship between the flash value and the depth of the venting grooves of different raw materials can be measured using a single mold. This can take into account the possible differences in flash gaps that may occur in different materials, and can achieve flash value measurement for various materials, with a wide coverage, thus facilitating the formation of references for subsequent mold design and avoiding flash formation on the molded product. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the mold core assembly according to an embodiment of the present invention;

[0024] Figure 2 This is a schematic diagram of the structure of the moving mold in an embodiment of the present invention;

[0025] Figure 3 yes Figure 2 A magnified view of a section at point A in the middle;

[0026] Figure 4 This is a schematic diagram of the structure of the test mold in an embodiment of the present invention;

[0027] Figure 5 This is a schematic diagram of the connection structure between the temperature sensor, pressure sensor, and controller;

[0028] In the diagram, 1 is the moving mold, 1a is the first cavity, 1b is the second cavity, 1c is the third cavity, 1d is the fourth cavity, 1e is the venting groove, 1f is the ventilation groove, 1g is the positioning groove, 2 is the fixed mold, 3 is the main runner, 4 is the feed port, 5 is the moving mold plate, 6 is the fixed mold plate, 7 is the fixed mold fixing plate, 8 is the ejection system, 9 is the positioning ring, and 10 is the heat insulation plate. Detailed Implementation

[0029] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] It should be understood that the terms "first," "second," etc., are used in this invention to describe various types of information, but these terms are not limited to them; they are only used to distinguish information of the same type from one another. For example, without departing from the scope of this invention, "first" information may also be referred to as "second" information, and similarly, "second" information may also be referred to as "first" information.

[0031] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0032] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will be further explained and described below with reference to the accompanying drawings and specific embodiments. The step numbers in the embodiments of the present invention are only for ease of explanation and do not limit the order of the steps. The execution order of each step in the embodiments can be adaptively adjusted according to the understanding of those skilled in the art.

[0033] like Figures 1 to 5As shown, a test mold according to a preferred embodiment of the present invention includes a mold core assembly for injection molding. The mold core assembly has at least two cavities. The mold core assembly includes a moving mold 1 and a fixed mold 2. The side of the moving mold 1 opposite to the fixed mold 2 is a first parting surface, and the side of the fixed mold 2 opposite to the moving mold 1 is a second parting surface. When the fixed mold 2 and the moving mold 1 are fitted together, the first parting surface and the second parting surface abut against each other. Each cavity has a plurality of venting grooves 1e on its outer side. The venting grooves 1e can discharge the gas in the cavity to the outside of the mold core assembly. The venting grooves 1e are set on the first parting surface and / or the second parting surface. The venting grooves 1e connected to the same cavity have the same depth, and the venting grooves 1e connected to different cavities have different depths.

[0034] Based on the above technical solution, by setting multiple cavities and creating venting grooves 1e of a certain depth outside each cavity, the relationship between the depth of the venting grooves 1e and the flash value can be obtained by observing the injection-molded product. This allows for the measurement of the true flash value of samples from the actual injection molding process, which is closer to the actual production situation and has strong authenticity. Furthermore, by changing the raw materials used in injection molding, the relationship between the flash value and the depth of the venting grooves 1e of different raw materials can be measured using a single mold. This can take into account the possible differences in flash gaps that may occur in different materials, enabling the measurement of flash values ​​for various materials with a wide coverage. This facilitates the formation of a reference for subsequent mold design, preventing flash from forming on the molded product.

[0035] In some embodiments of this application, there are four cavities, and the depths of the venting grooves 1e connected to the four cavities are all different, with the depths of the venting grooves 1e gradually increasing. The cavities are designated as first cavity 1a, second cavity 1b, third cavity 1c, and fourth cavity 1d, respectively. The depths of the venting grooves 1e in the first cavity 1a, second cavity 1b, third cavity 1c, and fourth cavity 1d gradually increase, thereby enabling the simultaneous formation of multiple sets of controls and allowing for simultaneous testing of the influence of various venting groove 1e depths on the overflow value for a single material.

[0036] In some embodiments of this application, the size and shape of each cavity are the same, and the width and length of each venting groove 1e are the same, thereby ensuring that the only variable is the depth of the venting groove 1e, thus ensuring that the parameters of each cavity are consistent, and ensuring that the depth of the venting groove 1e is the only variable affecting the overflow value, thereby ensuring that the obtained relationship is accurate and can serve as a reference.

[0037] In some embodiments of this application, an exhaust groove 1e is provided with a venting groove 1f, which is connected to the outer wall of the mold core assembly. The depth of the venting groove 1f is greater than the depth of the exhaust groove 1e. One end of the exhaust groove 1e is connected to the cavity, and the other end of the exhaust groove 1e is connected to the venting groove 1f, thereby facilitating the rapid discharge of gas.

[0038] In some embodiments of this application, the depth of the venting groove 1e ranges from 0.002 to 0.06 mm, thereby adapting to the injection molding requirements of various materials.

[0039] In some embodiments of this application, the extension direction of the venting groove 1e is denoted as the length direction, and the direction perpendicular to the extension direction of the venting groove 1e is denoted as the width direction. The width range of the venting groove 1e is 3mm-10mm, and the length of the venting groove 1e is 3mm-6mm, thereby ensuring that it serves a detection function while facilitating the processing of the mold core assembly.

[0040] In some embodiments of this application, the test mold further includes a controller (not shown in the figure), and each cavity is equipped with a temperature sensor (not shown in the figure) and a pressure sensor (not shown in the figure), both of which are electrically connected to the controller. Specifically, the first cavity 1a is equipped with a first temperature sensor and a first pressure sensor, the second cavity 1b is equipped with a second temperature sensor and a second pressure sensor, the third cavity 1c is equipped with a third temperature sensor and a third pressure sensor, and the fourth cavity 1d is equipped with a fourth temperature sensor and a fourth pressure sensor. The first temperature sensor, the first pressure sensor, the second temperature sensor, the second pressure sensor, the third temperature sensor, the third pressure sensor, the fourth temperature sensor, and the fourth pressure sensor are all electrically connected to the controller. By monitoring the temperature and pressure within the cavities, the actual filling state of the material during the injection molding process can be indirectly monitored. The relationship between temperature and pressure and flash can be statistically analyzed, providing a deeper and more refined characterization of the flash phenomenon.

[0041] In some embodiments of this application, the moving mold 1 is provided with a main flow channel 3 and a branch flow channel that are connected to each other, and the fixed mold 2 is provided with a feed port 4 for molten plastic material to enter. The main flow channel 3 is located opposite to the feed port 4. The main flow channel 3 is connected to each cavity through the branch flow channel. In this embodiment, each branch flow channel has the same length, thereby ensuring that the speed, temperature and pressure of the material flow in each cavity are the same, thereby ensuring the accuracy of the comparison test results.

[0042] In some embodiments of this application, the venting grooves 1e on the outer side of the same cavity are spaced apart along the flow direction of the plastic material on the outer side of the cavity, thereby enabling the monitoring of overflow phenomenon when the material flows at different flow lengths, and thus determining whether there is a relationship between the material flow distance and the overflow value.

[0043] In some embodiments of this application, when exhaust grooves 1e are provided on both the first parting surface and the second parting surface, the exhaust grooves 1e provided on the first parting surface and the exhaust grooves 1e provided on the second parting surface do not overlap, thereby avoiding the problem of increased exhaust groove depth caused by the relative arrangement of exhaust grooves 1e on both sides, which may affect the measurement results.

[0044] In some embodiments of this application, the test mold further includes a mold frame, which includes a heat insulation plate 10, a fixed mold fixing plate 7, a fixed template 6, a moving template 5, and a moving mold fixing plate. The fixed mold 2 is installed in the fixed template 6, and the moving mold 1 is installed in the moving template 5. An ejection system 8 is provided between the moving template 5 and the moving mold fixing plate. The ejection system 8 includes ejector pins and pin plates. A positioning ring 9 is provided on the fixed mold fixing plate 7 for positioning in conjunction with the injection molding machine nozzle, thereby facilitating the normal operation of injection molding and ejection.

[0045] In some embodiments of this application, positioning grooves 1g are provided on both the first parting surface and the second parting surface, which facilitates the positioning and installation of the moving mold 1 and the fixed mold 2, avoids errors in the assembly direction of the fixed mold 2 and the moving mold 1, and plays a role in preventing mistakes.

[0046] For the same purpose, the present invention also provides a method for evaluating overflow value, comprising the following steps:

[0047] S1. At least two cavities of the same shape and size are machined on the mold core assembly. Several venting grooves 1e are respectively opened on the parting surface of the mold core assembly. The venting grooves 1e connect the cavity and the outside of the mold core assembly. The venting grooves 1e connected to the same cavity have the same depth, and the venting grooves 1e connected to different cavities have different depths.

[0048] S2. After injection molding, observe the overflow around the solidified material in each cavity using a microscope;

[0049] S3. Input the overflow situation and the depth of the venting channel 1e into the controller. Use the controller to classify, statistically analyze and analyze the overflow situation based on the depth of the venting channel 1e, obtain the graph of the overflow situation between the depth of the venting channel 1e and the overflow situation, and store it in the controller.

[0050] In some embodiments of this application, the step S1 is followed by the following step:

[0051] During injection molding, temperature and pressure sensors installed in the cavity are used to obtain the temperature and pressure in each cavity.

[0052] Temperature and pressure are input into the controller. The controller classifies, statistically analyzes, and categorizes the temperature, pressure, and corresponding overflow conditions (including the length and thickness of the overflow edge) during injection molding, and generates a graph of temperature, pressure, and overflow conditions, which is then stored in the controller.

[0053] The working process of this invention is as follows: After injection molding, the overflow situation around the solidified material in each cavity is observed using a microscope. The overflow situation and the depth of the venting groove 1e are input into the controller. The controller classifies, statistically analyzes, and correlates the overflow situation with the depth of the venting groove 1e, generating a graph of the relationship between the depth of the venting groove 1e and the overflow situation, which is then stored in the controller. Simultaneously with injection molding, temperature and pressure sensors installed in the cavity are used to acquire the temperature and pressure within each cavity. The temperature and pressure are input into the controller. The controller classifies, statistically analyzes, and correlates the overflow situation with the temperature and pressure during injection molding, generating a graph of the relationship between temperature and pressure and the overflow situation, which is then stored in the controller.

[0054] Since the overflow phenomenon is directly dependent on the pressure and temperature during the filling process, temperature and pressure sensors are installed along the material flow direction in certain cavities. An external monitoring system monitors the mold temperature and cavity pressure at different locations within the mold cavity during the actual injection molding process. Using an optical microscope to observe and measure the overflow condition of the injection-molded sample allows for quantitative determination of whether overflow occurs at different overflow gaps and the overflow length.

[0055] In summary, the embodiments of the present invention provide a method for evaluating the flash value of a test mold. The test mold is configured with multiple cavities, and an venting groove 1e of a certain depth is set outside each cavity. By observing the injection-molded product, the relationship between the depth of the venting groove 1e and the flash value can be obtained. This method achieves a true measurement of the flash value of samples from the actual injection molding process, which is closer to the actual production situation and has strong authenticity. Furthermore, by changing the raw materials used in injection molding, the relationship between the flash value and the depth of the venting groove 1e of different raw materials can be measured with a single mold. This method can take into account the possible differences in flash gaps that may occur in different materials, and can achieve flash value measurement for various materials with a wide coverage. This facilitates the formation of a reference for subsequent mold design and avoids flash formation on the molded product.

[0056] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," "longitudinal," "X-axis direction," "Y-axis direction," and "Z-axis direction," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, some of the above terms, in addition to indicating orientation or positional relationships, may also be used to indicate other meanings; for example, the term "upper" may in some cases be used to indicate a certain dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances.

[0057] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and substitutions can be made without departing from the technical principles of the present invention, and these improvements and substitutions should also be considered within the scope of protection of the present invention.

Claims

1. A test mold, characterized in that, The device includes a mold core assembly for injection molding, the mold core assembly having at least two cavities, the mold core assembly including a moving mold and a fixed mold, the side of the moving mold opposite to the fixed mold being a first parting surface, and the side of the fixed mold opposite to the moving mold being a second parting surface, wherein when the fixed mold and the moving mold are fitted together, the first parting surface abuts against the second parting surface. Each cavity is provided with a plurality of venting grooves on its outer side. The venting grooves can discharge the gas in the cavity to the outside of the mold core assembly. The venting grooves are provided on the first parting surface and / or the second parting surface. The venting grooves connected to the same cavity have the same depth, while the venting grooves connected to different cavities have different depths. The cavity includes a first cavity and a second cavity, and the depth of the exhaust groove communicating with the second cavity is greater than the depth of the exhaust groove communicating with the first cavity. All cavities have the same size and shape, and all venting grooves have the same width and length. The moving mold has a main runner and branch runners that are connected to each other, and the fixed mold has a feed port for molten plastic material to enter. The main runner is located opposite to the feed port, and the main runner is connected to each cavity through the branch runners. All branch runners have the same length.

2. The test mold according to claim 1, characterized in that, The venting groove is provided with a ventilation groove outside the venting groove. The ventilation groove is connected to the outer wall of the mold core assembly. The depth of the ventilation groove is greater than the depth of the venting groove. One end of the venting groove is connected to the cavity, and the other end of the venting groove is connected to the ventilation groove.

3. The test mold according to claim 1, characterized in that, The extension direction of the exhaust groove is denoted as the length direction, and the direction perpendicular to the extension direction of the exhaust groove is denoted as the width direction. The width range of the exhaust groove is 3mm-10mm, and the length of the exhaust groove is 3mm-6mm.

4. The test mold according to claim 1, characterized in that, It also includes a controller, and each cavity is equipped with a temperature sensor and a pressure sensor, both of which are electrically connected to the controller.

5. The test mold according to claim 1, characterized in that, The venting grooves on the outer side of the same cavity are spaced apart along the flow direction of the plastic material on the outer side of the cavity.

6. The test mold according to claim 1, characterized in that, Both the first parting surface and the second parting surface are provided with exhaust grooves, and the exhaust grooves provided on the first parting surface and the exhaust grooves provided on the second parting surface do not overlap.

7. A method for evaluating overflow value using a test mold as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. At least two cavities of the same shape and size are machined on the mold core assembly. Several venting grooves are respectively opened on the parting surface of the mold core assembly. The venting grooves connect the cavity and the outside of the mold core assembly. The venting grooves connected to the same cavity have the same depth, and the venting grooves connected to different cavities have different depths. S2. After injection molding, observe the overflow around the solidified material in each cavity using a microscope; S3. Input the overflow situation and the depth of the venting channel into the controller. Use the controller to classify, statistically analyze and categorize the overflow situation based on the depth of the venting channel, obtain a graph of the venting channel depth and the overflow situation, and store it in the controller.

8. The overflow value evaluation method according to claim 7, characterized in that, The steps following step S1 include: During injection molding, temperature and pressure sensors installed in the cavity are used to obtain the temperature and pressure in each cavity. Temperature and pressure are input into the controller. The controller classifies, statistically analyzes, and categorizes the temperature, pressure, and corresponding overflow conditions during injection molding, and generates a graph of temperature, pressure, and overflow conditions, which is then stored in the controller.

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