Process for forming plastic clamshell-type cavity structure with flow guide partition inside

Abstract

The present invention relates to a process for forming a plastic clamshell-type cavity structure with a flow guide partition inside. According to the solution, pre-forming of two shells is first completed respectively by means of a pre-forming mold and two half injection molds, main body structures of the shells are cooled and shaped in the pre-forming stage, but an area to be welded is still in a high-temperature and weldable state; the two half injection molds are opened, and the pre-forming mold is moved out; the left and right half molds are closed for the second time, by means of a mold closing force, the shells in the two half molds make contact and are squeezed, and finally welding is implemented; by means of the positions of an inlet and an outlet of the product itself, the mold can introduce pressurized air into a cavity, thereby further enhancing the cooling and shaping of the product; and finally, the product is formed and taken out.

Description

A molding process for a plastic clamshell cavity structure with an internal flow guide partition Technical Field

[0001] The present invention relates to a molding process, in particular to a molding process of a plastic clamshell cavity structure with an internal flow guide partition, which belongs to the extension and expansion of the field of injection molding processing technology. Background Art

[0002] Parts with a plastic clamshell cavity structure with an internal flow-guiding partition are a relatively common type of parts in the injection molding field. Such parts are usually made of two separate parts on the left and right that are welded together to form a hollow cavity structure with a flow-guiding partition, such as common oil-gas separation parts, oil-liquid separation parts, etc.; if there are no strict sealing requirements between the flow-guiding partitions, a physical partition with a concave-convex fit can be used; if there are sealing requirements between the flow-guiding partitions, welding is generally used. In traditional technology, similar clamshell parts are usually completed by injection molding followed by heating and welding. In terms of hardware, two sets of equipment, injection molding and welding, are required, and in terms of process, the two processes, injection molding and welding, need to be coordinated and completed. Combined with many uncontrollable factors such as the logistics transfer of parts, the production cycle is long, the equipment investment is large, and there are many uncontrollable factors in the manufacturing process, so product quality control is also relatively difficult. Hot-melt welding has high technical requirements, usually with strict requirements on welding time, welding temperature, welding pressure, ambient temperature and other conditions. Even slight changes in process conditions can easily cause localized cold welds, leading to the risk of leakage. These defects are also difficult to detect after they occur. Therefore, a new solution is urgently needed to solve the above technical problems.

[0003] Summary of the Invention

[0004] The present invention is aimed at the problems existing in the prior art and provides a molding process for a plastic clamshell cavity structure with an internal flow guide partition. This technical solution solves the current problem of cold welds in clamshell parts, while improving production efficiency. It efficiently integrates the injection molding and welding processes, allowing welding to be completed directly during the injection molding process, simplifying the process flow and further ensuring product quality.

[0005] In order to achieve the above-mentioned object, the technical solution of the present invention is as follows: a molding process of a plastic clamshell cavity structure with an internal flow guide partition, the process comprising the following steps:

[0006] Step 1: The left and right mold halves are in a separated and open state, and the preform mold is initially set outside the mold movement range;

[0007] Step 2: The preform mold is moved between the left and right half molds via a mobile platform;

[0008] Step 3: The left and right mold halves move relative to each other and clamp the middle mold to complete one mold closing. The contours on both sides of the preforming mold are consistent with the parting surface contours of the left and right mold halves, forming two independent sealed cavities.

[0009] Step 4: The injection molding machine head injects molten rubber into the main gate of the preform mold. Under the action of injection pressure, the rubber is distributed through specially designed runners and injected into the left and right sealed cavities at the same time. The size and direction of the runners should be designed according to the size, weight and structural characteristics of the shells on both sides.

[0010] Step 5: After the injection is completed, the nozzle and the main gate of the preforming mold are separated. After a certain period of cooling and holding pressure, the left and right half molds preform two half shells. The cooling and holding time will be adjusted according to different products.

[0011] Step 6: The left and right mold halves are opened, and the preform mold moves out of the mold movement range. At this time, the shells in the two mold halves remain in their respective molds. By controlling the temperature of the mold and the middle mold, the main structure of the shell has basically cooled and solidified, but the area to be welded is in a high temperature and weldable state;

[0012] Step 7: After removing the preform mold, the left and right mold halves are clamped for a second time. The shells in the left and right mold halves are contacted and squeezed under the clamping force of the mold, and finally melted into one. At the same time, with the help of the product's own inlet and outlet positions, the mold will introduce pressurized air into the cavity to further enhance the cooling and shaping of the product;

[0013] Step 8: After a certain period of cooling and holding pressure, the product is completely cooled and shaped. The cooling and holding pressure time will be adjusted according to different products;

[0014] Step 9: The mold is opened and the product is taken out.

[0015] As an improvement of the present invention, an infrared heating device is provided on the outside of the preforming mold in step 1, and the infrared heating device and the preforming mold are fixed together, or the infrared heating device is provided in an independently moving device. In step 6, after the mold is opened for the first time, the preforming mold moves out of the movement range of the mold. At the same time, the infrared heating device on the outside of the preforming mold will be synchronously moved between the two half molds, and auxiliary heating is performed on the area to be welded of the shell in the two half molds. By controlling the temperature and heating time of the mold and the infrared heating device, the area to be welded of the two half shells is in a high-temperature weldable state.

[0016] As an improvement of the present invention, the movable platform is located between the two half molds and arranged in a cross shape with the mold opening direction of the injection molding machine, preferably in a spatial cross perpendicular to the mold opening direction. The movable platform is installed on a fixed base and can move under program control.

[0017] As an improvement of the present invention, the preforming mold is installed on a mobile platform. Driven by the mobile platform, the preforming mold can be moved in and out between the left and right half molds according to a set program.

[0018] As an improvement of the present invention, the contours of both sides of the preforming mold respectively match the parting lines of the corresponding half molds, and can form a sealed injection space with the corresponding half molds.

[0019] As an improvement to the present invention, the preform mold is equipped with a main gate and a bifurcated runner. The main gate can be located at the top of the preform mold to facilitate the injection and distribution of the rubber compound. The size and direction of the bifurcated runner are designed based on the size, weight, and structural characteristics of the shells on either side. After the preform mold and the left and right mold halves are closed, the rubber compound entering through the main gate can flow through the bifurcated runners into the left and right mold halves.

[0020] As an improvement to the present invention, the preform mold is equipped with an internal temperature control system, specifically employing a common hot runner system in the industry, to ensure that the rubber in the runner does not cool during operation. Furthermore, the preform mold's welded area is individually temperature-controlled, specifically by providing a separate water channel within the mold and utilizing a mold temperature controller for effective control.

[0021] As an improvement of the present invention, according to different product characteristics, the left and right injection mold halves include a temperature control system, which can be specifically achieved by locally setting up separate water channels and controlling the medium temperature in the water channels through a mold temperature controller.

[0022] Compared with the existing technology, the advantages of the present invention are as follows: the present invention can simultaneously complete the injection molding and welding of the two side shells on a single injection molding device, and its key process parameters such as welding temperature, pressure, time, etc. are controlled by the injection molding machine and the mold. Its parameters are relatively more controllable, the manufacturing process is shorter, and it is not easily disturbed by external uncontrollable factors. It effectively solves the defects of traditional processes that easily cause cold welding and improves the bonding quality of the joint position. In addition, the traditional process adopts a process of first injection molding, cooling and shaping, and then heating and welding. The temperature of the shell in the welding stage of the present invention is guaranteed by the residual heat of the product, so it is also more energy-saving and environmentally friendly. The process method of the present invention is particularly suitable for replacing the traditional welding process of a plastic clamshell cavity structure with an internal diversion partition. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic diagram of the initial state of the production process;

[0024] Figure 2 is a schematic diagram of the state where the preforming mold is moved between the two half molds;

[0025] FIG3 is a schematic diagram showing the first mold closing state when two mold halves move relative to each other and clamp the preform mold;

[0026] FIG4 is a schematic diagram showing the state where the two shells are completed and removed from the preforming mold;

[0027] Figure 5 is a schematic diagram of the secondary mold closing state of the two half molds;

[0028] Figure 6 is a schematic diagram of the secondary mold opening and product removal state;

[0029] Figure 7 is a schematic diagram of the flow channel structure;

[0030] Figures 8-15 are schematic diagrams of the entire production process in which an infrared heating device is provided on the outside of the preforming mold.

[0031] In the figure: 1, die head, 2, left mold half, 3, right mold half, 4, preforming mold, 5, nozzle, 6, main gate, 7, pressurized gas inlet, 8, pressurized gas inlet, 9, moving platform, 10, plastic clamshell cavity, 11, runner. DETAILED DESCRIPTION

[0032] In order to deepen the understanding of the present invention, this embodiment is described in detail below with reference to the accompanying drawings.

[0033] Example 1: Referring to Figures 1 to 7, a molding process for a plastic clamshell cavity structure with an internal flow guide partition is provided, the process comprising the following steps:

[0034] Step 1: Referring to FIG1 , the left mold half 2 and the right mold half 3 are in a separated open state, and the preform mold 4 is initially set outside the mold motion trajectory;

[0035] Step 2: Referring to FIG2 , the preforming mold 4 is moved between the left and right mold halves via the movable platform 9 ;

[0036] Step 3: Referring to FIG3 , the left and right mold halves move relative to each other and clamp the middle mold, i.e., the preform mold 4, to complete the first mold closing. In this scheme, the contours of the two sides of the preform mold 4 are consistent with the contours of the parting surfaces of the left and right mold halves, forming two independent sealed cavities.

[0037] Step 4: During the first mold closing process, the injection molding machine head 1 simultaneously injects molten rubber into the main gate 6 of the preform mold. Under the action of injection pressure, the rubber is distributed by the specially designed runner 11 and injected into the left and right sealed cavities at the same time. The size and direction of the runner should be designed according to the size, weight and structural characteristics of the shells on both sides;

[0038] Step 5: After the injection is completed, the nozzle 5 and the main gate 6 of the preforming mold are separated. After a certain period of cooling and holding pressure, the left and right half molds preform two half shells. The cooling and holding time will be adjusted according to different products.

[0039] Step 6: Referring to FIG4 , the left and right mold halves are opened, and the preform mold 4 is removed from the mold. At this time, the shells in the two mold halves remain in their respective molds. By controlling the temperature of the molds and the intermediate preform mold, the main structure of the shell has been basically finalized, but the area to be welded is in a high-temperature weldable state.

[0040] Step 7: Referring to FIG5 , after removing the preform mold 4, the left and right mold halves are clamped for a second time. The shells in the left and right mold halves are contacted and squeezed under the clamping force of the mold, and finally melted into one. At the same time, with the help of the product's own inlet and outlet positions, the mold introduces pressurized air into the cavity through the pressure gas inlet 1 to further enhance the cooling and shaping of the product.

[0041] Step 8: Refer to Figure 6. After a certain period of cooling and holding pressure, the product is completely cooled and shaped. The cooling and holding pressure time will be adjusted according to different products.

[0042] Step 9: The left and right mold halves are opened, the product is formed, and the product is taken out.

[0043] Example 2: Referring to Figures 8 to 15 , a molding process for a plastic clamshell cavity structure with an internal flow guide partition is provided, the process comprising the following steps:

[0044] Step 1: Referring to Figure 8 , the left and right mold halves 2 and 3 are in a separated, open position, and the preform mold 4 is initially positioned outside the mold's motion trajectory. In this embodiment, an infrared heating device is positioned outside the preform mold 4, which moves synchronously with the preform mold. Alternatively, the infrared heating device may be a separate, movable device.

[0045] Step 2: Referring to FIG9 , the preforming mold 4 is moved between the left and right mold halves via the movable platform 9 ;

[0046] Step 3: Referring to FIG10 , the left and right mold halves move relative to each other and clamp the middle mold, i.e., the preform mold 4, to complete the first mold closing. In this scheme, the contours of the two sides of the preform mold 4 are consistent with the contours of the parting surfaces of the left and right mold halves, forming two independent sealed cavities.

[0047] Step 4: During the first mold closing process, the injection molding machine head 1 simultaneously injects molten rubber into the main gate 6 of the preform mold. Under the action of injection pressure, the rubber is distributed by the specially designed runner 11 and injected into the left and right sealed cavities at the same time. The size and direction of the runner should be designed according to the size, weight and structural characteristics of the shells on both sides;

[0048] Step 5: After the injection is completed, the nozzle 5 and the main gate 6 of the preforming mold are separated. After a certain period of cooling and holding pressure, the left and right half molds preform two half shells. The cooling and holding time will be adjusted according to different products.

[0049] Step 6: Referring to Figures 11 and 12, the left and right mold halves are opened, and the pre-forming mold 4 is moved out of the mold. At this time, the shells in the two half molds still remain in their respective molds, and the pre-forming mold moves out of the movement range of the mold. At the same time, the infrared heating device on the outside of the pre-forming mold will be synchronously moved between the two half molds and auxiliary heating is performed on the shells in the two half molds to be welded. By controlling the temperature and heating time of the mold and the infrared heating device, the areas to be welded of the two half shells are kept in a high-temperature weldable state.

[0050] Step 7: Referring to FIG14 , after removing the preform mold 4, the left and right mold halves are clamped for a second time. The shells in the left and right mold halves are contacted and squeezed under the clamping force of the mold, and finally melted into one. At the same time, with the help of the product's own inlet and outlet positions, the mold introduces pressurized air into the cavity through the pressure gas inlet 1 to further enhance the cooling and shaping of the product.

[0051] Step 8: See Figure 15. After a certain period of cooling and holding pressure, the product is completely cooled and shaped. The cooling and holding pressure time will be adjusted according to different products.

[0052] Step 9: The left and right mold halves are opened, the product is formed, and the product is taken out.

[0053] Example 3: Referring to Figures 1-7 , in the above scheme, the movable platform is positioned between the two mold halves, arranged crosswise with the mold opening direction of the injection molding machine, preferably in a spatial cross configuration. The movable platform is mounted on a fixed base and can be moved under program control. The remaining design is identical to that of Examples 1 or 2.

[0054] Example 4: Referring to Figures 1-7 , in the above-described embodiment, preform mold 4 is mounted on a movable platform 9. Driven by the movable platform, preform mold 4 can be moved in and out between the left and right mold halves according to a pre-set program. The contours of the two sides of the preform mold align with the parting lines of the corresponding mold halves, forming a sealed injection space with the corresponding mold halves. The remaining design is identical to that of Examples 1 or 2.

[0055] Example 5: Referring to Figures 1-7 , in the above-described embodiment, the preform mold 4 is provided with a main gate 6 and a bifurcated runner 11. The main gate 6 can be positioned at the top of the preform mold to facilitate injection and distribution of the rubber compound. The size and orientation of the bifurcated runner 11 should be designed based on the size, weight, and structural characteristics of the housings on either side. After the preform mold and the left and right mold halves are closed, the rubber compound entering through the main gate can be routed through the bifurcated runners to the left and right mold halves. The remaining design is identical to that of Examples 1 or 2.

[0056] Example 6: Referring to Figures 1-7, in the above scheme, the preform mold is equipped with an internal temperature control system. Specifically, a common hot runner system can be used to ensure that the rubber in the runner does not cool during operation. Furthermore, the preform mold's welded area is independently temperature-controlled. Specifically, a separate water channel can be provided within the mold and effectively controlled using a mold temperature controller. The remaining design is identical to that of Examples 1 or 2.

[0057] Example 7: Referring to Figures 1-7 , in the above scheme, depending on the product characteristics, the left and right injection mold halves include a temperature control system. Specifically, this can be achieved by locally providing separate water channels, with the medium temperature in the channels controlled by a mold temperature controller. The remaining design is identical to that of Examples 1 or 2.

[0058] The present invention can also combine at least one of the technical features described in Examples 3, 4, 5, 6, and 7 with Example 1 or 2 to form a new implementation method.

[0059] The present invention can simultaneously complete the injection molding and welding of the two shells on a single injection molding machine. Key process parameters such as welding temperature, pressure, and time are controlled by the injection molding machine and mold. These parameters are relatively more controllable, the manufacturing process is shorter, and it is less susceptible to interference from external uncontrollable factors. This effectively solves the defects of traditional processes that easily cause cold welds and improves the joint quality of the joints. Furthermore, while traditional processes use a process of injection molding, cooling, and shaping, followed by heating and welding, the present invention relies on the residual heat of the product to ensure the temperature of the shell during the welding stage, making it more energy-efficient and environmentally friendly.

[0060] It should be noted that the above embodiments are not intended to limit the scope of protection of the present invention, and equivalent changes or substitutions made on the basis of the above technical solutions fall within the scope of protection of the claims of the present invention.

Claims

1. A molding process of a plastic clamshell cavity structure with an internal flow guide partition, characterized in that: The process comprises the following steps: Step 1: The left and right mold halves are in a separated open state, and the preform mold is initially set outside the mold movement range; Step 2: The preform mold is moved between the two half molds through a mobile platform; Step 3: The left and right half molds move relative to each other and clamp the preforming mold to complete a mold closing. The contours on both sides of the preforming mold are consistent with the contours of the parting surfaces of the left and right half molds, and two independent sealed cavities are formed. Step 4: The nozzle of the injection molding machine injects molten rubber into the main gate of the preform mold. Under the action of injection pressure, the rubber is distributed through the runner and injected into the left and right sealed cavities at the same time; Step 5: After the injection is completed, the nozzle and the main gate of the preforming mold are separated, and after cooling and pressure holding, the left and right half molds preform two half shells; Step 6: The mold is opened, and the preform mold moves out of the moving range of the mold. At this time, the shells in the two half molds still stay in their respective molds. By controlling the temperature of the mold and the preform mold, the main structure of the shell has been cooled and shaped, and the area to be welded is in a high-temperature weldable state; Step 7: After removing the preform mold, the mold is closed for the second time. The shells in the left and right half molds contact and squeeze each other under the mold clamping force, and finally melt into one. At the same time, with the help of the product's own inlet and outlet positions, the mold will introduce compressed air into the cavity to strengthen the cooling and shaping of the product inside. Step 8: After cooling and holding pressure, the product is completely cooled and shaped; Step 9: The mold is opened and the product is taken out.

2. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 1 is characterized in that: In step 1, an infrared heating device is arranged on the outer side of the preforming mold, and the infrared heating device and the preforming mold are fixed together, or the infrared heating device is arranged in an independently moving device. In step 6, after the mold is opened for the first time, the preforming mold moves out of the moving range of the mold. At the same time, the infrared heating device on the outer side of the preforming mold will be synchronously moved between the two half molds, and the area to be welded of the shell in the two half molds will be auxiliary heated. By controlling the temperature and heating time of the mold and the infrared heating device, the area to be welded of the two half shells is in a high-temperature weldable state.

3. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 1 or 2, characterized in that: The mobile platform is located between the two half molds and arranged in a cross shape with the mold opening direction of the injection molding machine. The mobile platform is installed on a fixed base and moves under the control of the program.

4. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 3 is characterized in that: The preforming mold is installed on a mobile platform. Driven by the mobile platform, the preforming mold moves in and out between the left and right half molds according to a set program.

5. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 4 is characterized in that: The contours on both sides of the preforming mold are respectively matched with the parting lines of the corresponding half molds, forming a sealed injection space with the corresponding half molds.

6. The injection molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 5, characterized in that: The preforming mold is provided with a main gate and a bifurcated flow channel. When the preforming mold and the left and right half molds are closed, the rubber material entering from the main gate enters the left and right half molds respectively through the bifurcated flow channel.

7. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 6 is characterized in that: The interior of the preforming mold is equipped with a temperature control system and a hot runner system is used to ensure that the rubber in the runner will not cool down during the working time.

8. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 1 is characterized in that: A temperature control system is set in the left and right half molds, and a separate water channel is set locally. The temperature of the medium in the water channel is controlled by a mold temperature controller.

9. The molding process of the plastic clamshell cavity structure with internal flow guide partition according to claim 8, characterized in that: The shell of the plastic clamshell cavity structure parts processed by this process has inlets and outlets for fluid to flow in and out. After the mold is closed for the second time, pressurized gas is introduced into the inlet and outlet positions of the shell on both sides to enhance the cooling and shaping inside the shell.

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