Environment-friendly in-mold coating processing device and process for plastic product

Abstract

The present application discloses an environment-friendly in-mold coating processing device for a plastic product. The device comprises an in-mold coating apparatus, a color paste conveying apparatus, a mixing head, and a mold. The in-mold coating apparatus comprises a material A tank for supplying a material A, and a material B tank for supplying a material B. The color paste conveying apparatus comprises material C tanks for supplying a material C. The material A, the material B, and the material C are mixed inside the mixing head to form a reaction molding coating. A discharge end of the mixing head is connected to a coating feed end of the mold. The environment-friendly in-mold coating processing device for a plastic product of the present application has a high device integration level, can reduce processing procedures, is stable, is flexible and convenient to operate, allows to obtain high-quality product surfaces having a plurality of color effects, can flexibly and freely work in conjunction with different types of injection molding machines and mold flip frame devices according to user production requirements, and thus can meet user production requirements in different application scenarios.

Description

An environmentally friendly in-mold coating equipment and process for plastic products

[0001] Cross-reference to related applications: This application claims priority to Chinese Patent Application No. 202411601942.5, filed on November 11, 2024, entitled “An Environmentally Friendly In-Mold Coating Process for Plastic Products”, which is incorporated herein by reference in its entirety. Technical Field

[0002] This application relates to the field of plastic molding technology, and in particular to an environmentally friendly in-mold coating processing equipment and process for plastic products. Background Technology

[0003] Spray painting is a common process for coating plastic products. However, existing spray painting equipment often suffers from limited spraying range due to the relatively fixed nozzles, failing to fully cover the surface of the plastic product and resulting in uneven coating, poor paint quality, and low yield. Furthermore, paint spilled on the workbench or in the workshop during spraying can severely pollute the environment and is difficult to clean. For high-end plastic products, the manufacturing process typically requires multiple steps, leading to low processing efficiency.

[0004] Existing technologies address the shortcomings of poor finished product quality and environmental pollution in spray painting processes. For example, Chinese patent CN213222874U discloses a spray painting device for automobile grille production. This device adjusts the horizontal position, height, and rotation of the spray head through the cooperation of components such as a first electric telescopic rod, a motor, a third gear, a second electric telescopic rod, a square rod, and a working arm. It also collects spilled paint through a collection box and a recess, solving the problems of uneven spraying and severe environmental pollution caused by paint spills on the workbench or in the workshop, which are difficult to clean. However, the technical solution disclosed in CN213222874U still suffers from cumulative errors during the adjustment of the various components of the spray painting device, resulting in deviations in paint thickness and precision, thus affecting the quality of the painted product. Furthermore, the aforementioned technical solution only adds a collection box and a recess to collect spilled paint and does not fundamentally solve the pollution source in the workshop.

[0005] In-mold injection molding for surface decoration is primarily used in the automotive industry for interior and exterior trim, as well as in the surface decoration and functional panels of home appliances. However, large films are prone to localized cracking or deformation during deep-cavity or irregularly shaped molding processes, resulting in lower shape and positional accuracy of surface patterns or text. Therefore, its application on large, deep-cavity, and irregularly shaped parts (such as laptop panels and automotive interior components) is challenging. Furthermore, the difficulty and complexity of positioning large films within the mold, requiring significant time for setup and adjustments, leads to low production efficiency and limited application scenarios.

[0006] Existing technologies address the shortcomings of in-mold injection surface decoration processes, which are difficult to apply to large films. For example, Chinese patent CN108727797A discloses a polycarbonate substrate for in-mold decoration and its preparation method: by blending branched polycarbonate with copolyester, the thermal tensile deformation and puncture resistance of polycarbonate are improved, enabling the application of polycarbonate films in deep cavities and irregularly shaped parts. However, the technical solution disclosed in CN108727797A still suffers from positioning errors during the installation process of the polycarbonate film; the substrate of the above technical solution is limited to modified and optimized polycarbonate materials, which limits the selection of product substrates; and the large films of the above technical solution are prone to local cracking or deformation during the molding process, resulting in low and blurry shape and position accuracy of patterns and text on the product surface.

[0007] Reaction molding in-mold coating process can overcome, to some extent, the shortcomings of spray painting and in-mold injection surface decoration processes, such as poor finished product quality, environmental pollution, and difficulty in being applied to large films. Typically, the material product (substrate product) is first injection molded, and then the material product is transported to the second PU layer process for further processing.

[0008] Existing reaction molding in-mold coating processes, such as the multi-material injection molding machine and its multi-material injection method disclosed in Chinese Patent CN110978387A, involve the following steps: First, the mold is closed to inject part a; second, the mold is opened to move part a to the first PU fixed mold base; third, the mold is closed again to perform PU layer injection on part a and inject part b; fourth, the mold is opened again to move part b to the second PU fixed mold base; fifth, the mold is closed again to perform PU layer injection on part b and inject part a'; sixth, the mold is opened again to remove part a from the first PU fixed mold base and move part a' to the first PU fixed mold base. The technical solution disclosed in CN110978387A requires transferring the position of the injection molding substrate from position A to position B during the process of applying a polyurethane coating to the surface of the injection molding substrate, and changing it from one fixed mold cavity to another. This involves an alternating substrate transfer process, which introduces positioning errors due to the need for secondary product positioning. The polyurethane injection equipment is connected to the polyurethane fixed mold base and is mounted on the front template. The injection molded part needs to be clamped on the fixed mold base, and tooling fixtures need to be installed on the mold. The numerous process steps lead to complex equipment operation and low production efficiency. Furthermore, this solution requires connecting the PU fixed mold base to a compressed air source, which is used to circulate compressed air through the PU fixed mold. To ensure the molding effect of the PU layer inside the PU fixed mold base, compressed air needs to be injected into the PU fixed mold base before injecting the PU. This solution increases production time, affects efficiency, and increases the investment in auxiliary equipment for vacuuming and compressed air circulation. In addition, the technical solution disclosed in CN110978387A requires connecting the PU mold base to a compressed air source. The compressed air source is used to circulate compressed air through the PU mold base. In order to ensure the molding effect of the PU layer inside the PU mold base, compressed air needs to be injected into the PU mold base before injecting PU. This solution will increase production time and affect efficiency, as well as increase the investment in auxiliary equipment for vacuuming and circulating compressed air.

[0009] Existing reaction molding in-mold coating processes still suffer from the problem of limited color options for PU surface layers, resulting in fewer product colors available to customers. Adding color paste to the PU material tank also leads to significant time consumption during subsequent color switching, thus impacting production efficiency.

[0010] In summary, although the existing reaction molding in-mold coating process can overcome some of the technical defects of spray painting and in-mold injection surface decoration processes, it still has the disadvantages of complicated production processes, low efficiency, large amount of production equipment and auxiliary machines, large factory space occupation, high investment costs, and limited product color. Summary of the Invention

[0011] To address one or more technical problems in the prior art, this application provides an environmentally friendly in-mold coating processing device for plastic products.

[0012] An environmentally friendly in-mold coating processing equipment for plastic products includes an in-mold coating device, a color paste conveying device, a mixing head, and a molding die. The in-mold coating device includes an A material tank for supplying material A and a B material tank for supplying material B. The color paste conveying device includes a C material tank for supplying material C. The A material, the B material, and the C material are mixed inside the mixing head to form a reaction molding coating. The discharge end of the mixing head is connected to the coating inlet end of the molding die.

[0013] The A material tank is connected to the inlet A of the mixing head through the discharge pipe A and the return pipe A;

[0014] The B material tank is connected to the inlet B of the mixing head through the discharge pipe B and the return pipe B;

[0015] The C material tank is connected to the inlet C of the mixing head through the discharge pipe C and the return pipe C;

[0016] The mixing head is equipped with a cleaning rod and a control rod. The cleaning rod is used to clean the paint residue inside the mixing head and block the discharge port of the mixing head. The control rod is used to block or open the inlet A, the inlet B and the inlet C.

[0017] When the control lever is in the closed position: material A can circulate in material A tank, discharge pipe A and return pipe A; material B can circulate in material B tank, discharge pipe B and return pipe B; and material C can circulate in material C tank, discharge pipe C and return pipe C.

[0018] Preferably, the A material tank, the B material tank, and the C material tank are all connected to a temperature control device. The temperature control device includes a water-type raw material temperature controller. The water-type raw material temperature controller is connected to a jacketed heat exchanger located outside the A material tank and the B material tank through a water supply pipe. The jacketed heat exchanger is provided with a heat insulation layer on its exterior.

[0019] Preferably, both material tank A and material tank B are connected to a raw material agitator, which can continuously or indirectly agitate the raw materials.

[0020] Preferably, both material tank A and material tank B are connected to low-pressure feeding pumps, and the two low-pressure feeding pumps are respectively connected to different high-pressure metering pumps through pipelines.

[0021] Preferably, the high-pressure metering pump is installed inside the insulation box, and the insulation box is also equipped with a volumetric flow meter, which is connected to the high-pressure metering pump through a pipeline.

[0022] Preferably, both material tank A and material tank B are connected to a vacuum generator.

[0023] Preferably, the mixing head is connected to a hydraulic power station, and the cleaning rod and the control rod are extended and retracted by hydraulic power provided by the hydraulic power station.

[0024] Preferably, the A material tank, the B material tank, and the hydraulic power station are all mounted on the first bracket, and the first bracket is also equipped with an AB material electrical control cabinet and an AB material automatic replenishment device.

[0025] Preferably, the color paste conveying device is mounted on the color paste station bracket.

[0026] Preferably, the environmentally friendly in-mold coating processing equipment for plastic products further includes an injection molding device, which is equipped with an automatic plastic feeding device, a hopper, and a raw material drying system.

[0027] Preferably, the forming mold includes a sliding platen and a fixed platen;

[0028] The sliding template is provided with two half molds, half mold one and half mold two, and the fixed template is provided with half mold three. Half mold one and half mold two can be switched to dock with half mold three by translation and sliding.

[0029] The third half-mold is connected to the discharge end of the injection molding device and the discharge end of the mixing head;

[0030] The first half-mold and the third half-mold are combined to form an injection molded substrate cavity;

[0031] The two semi-molds are combined with the three semi-molds to form a reaction molding coating cavity.

[0032] Preferably, the forming mold includes a moving mold plate and a front mold plate;

[0033] The moving template is equipped with a rotating mechanism that can rotate 360° along the vertical axis, and the moving template is also equipped with a horizontal moving mechanism. The moving template includes a first half-mold and a second half-mold.

[0034] The front template is equipped with a horizontal moving mechanism, and the front template includes a third half-mold and a fourth half-mold.

[0035] The third half-mold is connected to the discharge end of the injection molding device, and the first half-mold and the second half-mold can both be closed with the third half-mold to form an injection molded substrate cavity;

[0036] The fourth half-mold is connected to the discharge end of the mixing head, and the first half-mold and the second half-mold can both be molded together with the fourth half-mold to form a reaction molding coating cavity.

[0037] Preferably, an automatic part-removing device for removing workpieces from the forming mold is provided on one side of the forming mold, and an automatic trimming device for trimming workpieces is provided on one side of the automatic part-removing device. Both the automatic part-removing device and the automatic trimming device are installed in an automated isolation guardrail.

[0038] Preferably, the number of C material tanks is two or more.

[0039] Preferably, the environmentally friendly in-mold coating equipment for plastic products is controlled by digital signal input and output logic, wherein the control logic of the digital signals includes one or more of the following:

[0040] D1. When the environmentally friendly in-mold coating processing equipment for plastic products malfunctions, output a "DO mechanical fault" signal;

[0041] D2. When the first half-mold and the third half-mold are joined to form the injection molding substrate cavity, the system outputs a "DO cleaning rod advance" signal and continues to output the signal until the "DO ready to foam" signal is output. After the cleaning rod advances to the correct position, the system outputs a "DI cleaning rod advance to the correct position" signal, which is active high.

[0042] D3. When the environmentally friendly in-mold coating processing equipment for plastic products is in semi-automatic / fully automatic mode, it outputs a "DO automatic operation" signal;

[0043] D4. When the reaction molding coating cavity is formed after the mold is closed, the "DO prepare to foam" signal is triggered, and the "DO prepare to foam" signal is disconnected before the "DO start foaming" signal is output.

[0044] D5. When the system receives the "DI ready to foam" signal, it outputs the "DO start foaming" signal; when the system receives the "DI foaming complete" signal, it disconnects the "DO start foaming" signal output and enters the foaming and cooling timer. The "DI foaming complete" signal is active high. The "DI ready to foam" signal is active high, and the "DO start foaming" signal output is prohibited if a high-level signal is not received. The "DI foaming complete" signal is active high.

[0045] D6. When the foaming machine is foaming, the system outputs a "DI is foaming" signal. The "DI is foaming" signal is active at a high level and there is no alarm output.

[0046] D7. The "DO blow cleaning rod" signal is triggered by the "DI foaming complete" signal;

[0047] D8. When the foaming machine malfunctions, the system outputs a "DI foaming machine malfunction" signal. The "DI foaming machine malfunction" signal is active at a high level. When the "DI foaming machine malfunction" signal is input into the system, the system alarms "foaming machine malfunction" and prohibits the system from entering the automatic mode with "foaming action". If in automatic mode, it will jump to manual mode after the cycle ends.

[0048] D9. When the downstream equipment of the injection molding machine detects a defective product, it inputs a "DI product defective" signal to the system. The "DI product defective" signal is active high.

[0049] In order to solve one or more technical problems in the prior art, this application also provides an environmentally friendly in-mold coating process for plastic products.

[0050] An environmentally friendly in-mold coating process for plastic products, comprising the following steps:

[0051] S01. Mold closing, at this time the first half mold and the third half mold close to form the injection base cavity of the first workpiece, and the injection device injects the first workpiece base material into the injection base cavity;

[0052] S02. Keep the mold closed and perform pressure holding and cooling shaping of the first workpiece substrate;

[0053] S03. Mold opening: The first workpiece substrate is attached to the first half mold. After the moving mold plate rotates 180°, the mold is closed. At this time, the first half mold and the fourth half mold are closed to form a reaction molding coating cavity containing the first workpiece substrate. The second half mold and the third half mold are closed to form an injection molding substrate cavity for the second workpiece.

[0054] S04. While keeping the mold closed, the mixing head injects the reactive molding coating onto the surface of the first workpiece substrate, and the injection molding device simultaneously injects the second workpiece substrate;

[0055] S05. While the mold is closed, the reaction molding coating reacts and forms on the surface of the first workpiece substrate, and the pressure holding and cooling of the second workpiece substrate are carried out simultaneously.

[0056] S06. The mold is opened, the first workpiece after coating is attached to the first half mold, the second workpiece substrate is attached to the second half mold, and the automatic part removal device removes the first workpiece after coating from the first half mold;

[0057] S07. After the moving template rotates 180°, the mold is closed. At this time, the second half mold and the fourth half mold are closed to form a reaction molding coating cavity containing the second workpiece substrate. The first half mold and the third half mold are closed to form an injection molding substrate cavity for the third workpiece.

[0058] S08. While the mold is closed, the mixing head injects the reactive molding coating onto the surface of the second workpiece substrate, and the injection molding device simultaneously injects the third workpiece substrate;

[0059] S09. While the mold is closed, the reaction molding coating reacts and forms on the surface of the second workpiece substrate, and the pressure holding and cooling of the third workpiece substrate are carried out simultaneously.

[0060] S010. The mold is opened, the second workpiece with the coating completed is attached to the second half mold, the third workpiece substrate is attached to the first half mold, and the automatic part removal device removes the second workpiece with the coating completed from the second half mold.

[0061] Preferably, the injection molding substrate material of the injection molding device includes one or more of polypropylene, PC, ABS, PC+ABS, PA66 and carbon fiber.

[0062] Preferably, when the reaction molding coating is polyurethane, and the molding die includes the moving mold plate and the front mold plate, the melting temperature of the barrel of the injection molding device is 200℃~320℃, the mold temperature of the first half mold, the second half mold and the third half mold is 80℃~110℃, the mold temperature of the fourth half mold is 90℃~130℃, the temperature at which the polyurethane material enters the reaction molding coating cavity is 60℃~90℃, the working pressure of the polyurethane material entering the reaction molding coating cavity is 11MPa~21MPa, and the curing time of the polyurethane material in the reaction molding coating cavity is 20s~200s.

[0063] Preferably, the injection molding substrate material is polypropylene, the melting temperature of the injection molding device barrel is 170℃~250℃, and the injection molding substrate is a polypropylene substrate. The in-mold coating process of the polypropylene substrate includes the following steps:

[0064] S11. The injection molding device injects a polypropylene substrate into the injection molding substrate cavity;

[0065] S12. The injection-molded polypropylene substrate is rotated and sent to the PLASMA surface treatment equipment (model SPA2800) for plasma treatment.

[0066] S13. Inject polyurethane material into a molded surface of a plasma-treated polypropylene substrate;

[0067] S14. Open the mold and remove the part to obtain the finished product in which polypropylene and polyurethane materials are bonded together.

[0068] Preferably, the technical parameters of the PLASMA surface treatment equipment are: voltage 190V~250V, frequency 40Hz~60Hz, current 0.25A~0.35A, air pressure 0.4bar~0.8bar, and processing width 20~90mm.

[0069] Preferably, the voltage is 220V, the frequency is 50Hz, the current is 0.31A, the air pressure is 0.6bar, and the processing width is 75mm.

[0070] Preferably, the technical parameters of the PLASMA surface treatment equipment are as follows: the height of the plasma from the substrate surface is 8mm to 15mm, the plasma moving speed is 50mm / s to 150mm / s, and the plasma temperature is 70℃ to 100℃.

[0071] Preferably, the plasma is 10 mm above the substrate surface, moves at a speed of 100 mm / s, and has a temperature of 90 °C.

[0072] The beneficial effects of this application are:

[0073] (1) This application can solve the technical problem of low production efficiency caused by the cumbersome process and equipment in the existing technology:

[0074] Chinese patent CN117382096A discloses the application of PUR in-mold spraying injection molding technology in the production of interior automotive lights. This patent mentions multiple color schemes available, but does not disclose the method. Chinese patent CN101400498A discloses a method and equipment for manufacturing multi-component plastic molded parts. This patent does not provide guidance on setting up a color paste delivery device. Those skilled in the art, referring to this patent's solution, can only conceive of adding color paste to tank A or tank B. Changing colors requires cleaning tank A or tank B, a cumbersome and inefficient process that leads to material waste. This patent, however, by setting up a color paste delivery device and setting the number of tanks C to two or more, allows for rapid switching of reaction molding coating colors by switching the connection between the inlet C and different tanks C. Furthermore, it eliminates the need to clean the tanks, resulting in high production efficiency, environmental friendliness, and cost savings.

[0075] Chinese patent CN114147915A discloses an in-mold spraying system and its process. This patent involves moving the mold left and right, first injecting the substrate, then moving the mold to the PU cavity for painting, and then opening the mold again to move it to the substrate cavity for substrate injection. Only one individual cavity can be produced at a time. Based on the processing steps S01~S010 provided by this patent, the produced substrate can be moved to the PU cavity, painted, and simultaneously injected into the substrate on the other side. This can be continuously cycled and alternated, significantly improving efficiency.

[0076] The conventional processing method in the prior art is to first injection mold the material (substrate) product, and then transport the substrate to the mold for in-mold coating. This method is cumbersome, resulting in low production efficiency and large product positioning errors. This application combines reaction molding equipment and injection molding equipment, which can effectively reduce the in-mold painting process and achieve the coating process in one step without demolding the product, thus solving the problems of product deformation and positioning difficulties.

[0077] (2) This application can solve the technical problems of existing technology equipment occupying a large factory space, low equipment system integration, and requiring a large investment in auxiliary equipment:

[0078] In existing technologies, heating devices, electrical control cabinets, material tanks, and vacuum systems are scattered. The equipment and system in this application have a high degree of integration, effectively reducing the footprint. Traditional two-step painting processes require numerous auxiliary equipment; this patent is applicable to one-step painting processes, reducing auxiliary equipment investment and saving space. The temperature control device in this patent employs a nested water channel design for the material tanks. The small water temperature control system occupies little space, reducing the space required for hot air heating and large mold temperature controllers used in existing technologies. This patent integrates the vacuum generators into the material tanks for materials A and B respectively, further reducing space requirements and the investment in vacuum auxiliary equipment.

[0079] (3) The processing equipment and processing technology provided in this application are very environmentally friendly:

[0080] Existing spraying equipment suffers from drawbacks such as high pollution, high energy consumption, numerous processes, and low efficiency. This application employs an in-mold one-step coating process, eliminating the need for multiple workstations and paint, and perfectly matching reaction-cured coatings. Compared to existing technologies, the equipment and process of this application offer advantages such as greater environmental friendliness, lower energy consumption, fewer processes, and higher efficiency. Attached Figure Description

[0081] The accompanying drawings are provided to further understand this application and form part of the specification. They are used together with the embodiments of this application to explain this application and do not constitute a limitation thereof.

[0082] Figure 1 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0083] Figure 2 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0084] Figure 3 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0085] Figure 4 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0086] Figure 5 is a schematic diagram of a mixing head according to an embodiment of this application;

[0087] Figure 6 is a schematic diagram of the connection between the material tank and the vacuum generator according to an embodiment of this application;

[0088] Figure 7 is a photograph of the first defect;

[0089] Figure 8 is a photograph of the second defect;

[0090] Figure 9 is a photo of the third adverse phenomenon;

[0091] Figure 10 is a photo of the fourth defect;

[0092] Figure 11 is an overview of the turntable mode I / O signal block diagram according to an embodiment of this application;

[0093] Figure 12 is an overview of the slide mode I / O signal block diagram according to an embodiment of this application;

[0094] Figure 13 is a logic diagram of the system for handling non-conforming products according to an embodiment of this application;

[0095] Figure 14 is a schematic diagram of an environmentally friendly in-mold coating process for plastic products according to an embodiment of this application;

[0096] Figure 15 is a schematic diagram of mold texture according to an embodiment of this application;

[0097] Figure 16 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0098] Figure 17 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0099] Figure 18 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0100] Figure 19 is a schematic diagram of an environmentally friendly in-mold coating equipment for plastic products according to an embodiment of this application;

[0101] In the diagram: 1. In-mold coating device; 101. Material tank A; 1011. Discharge pipe A; 1012. Return pipe A; 102. Material tank B; 1021. Discharge pipe B; 1022. Return pipe B; 103. Raw material mixer; 104. Low-pressure feed pump; 105. Insulation box; 106. Vacuum generator; 2. Pigment conveying device; 201. Material tank C; 2011. Discharge pipe C; 2012. Return pipe C; 3. Mixing head; 301. Inlet A; 302. Inlet B; 303. Inlet C; 304. Cleaning rod 305. Control lever; 306. Hydraulic power station; 4. Molding mold; 401. First half mold; 402. Second half mold; 403. Third half mold; 404. Fourth half mold; 5. Temperature control device; 501. Water-type raw material temperature controller; 601. Bracket one; 6011. AB material electrical control cabinet; 6012. AB material automatic replenishment equipment; 602. Bracket two; 7. Injection molding device; 701. Automatic replenishment equipment; 8. Automated isolation guardrail; 801. Automatic part picking device; 802. Automatic trimming device; 9. Centralized control system. Detailed Implementation

[0102] The present application will be further described in detail below with reference to the embodiments. The following embodiments are explanations of the present application, but the present application is not limited to the following embodiments.

[0103] The various embodiments according to this application will now be described in detail with reference to the accompanying drawings.

[0104] As shown in Figures 1-19, an environmentally friendly in-mold coating processing equipment for plastic products includes an in-mold coating device 1, a color paste conveying device 2, a mixing head 3, and a molding die 4. The in-mold coating device 1 includes an A material tank 101 for supplying material A and a B material tank 102 for supplying material B. The color paste conveying device 2 includes a C material tank 201 for supplying material C. The A material, the B material, and the C material are mixed inside the mixing head 3 to form a reaction molding coating. The discharge end of the mixing head 3 is connected to the coating inlet end of the molding die 4.

[0105] In practical application, the preferred reaction molding coating of this patent is polyurethane (PUR), in which component A is a polyether polyol, component B is an isocyanate, and component C is a polyether polyol containing colorant / pigment. Besides polyurethane, the reaction molding coating can also be polyurea (PUA) or other two-component or multi-component coatings.

[0106] The A material tank 101 is connected to the inlet A301 of the mixing head 3 through the discharge pipe A1011 and the return pipe A1012;

[0107] The B material tank 102 is connected to the inlet B302 of the mixing head 3 through the discharge pipe B1021 and the return pipe B1022;

[0108] The C material tank 201 is connected to the inlet C303 of the mixing head 3 through the discharge pipe C2011 and the return pipe C2012;

[0109] In the specific design, the discharge pipe A1011, return pipe A1012, discharge pipe B1021, return pipe B1022, discharge pipe C2011, and return pipe C2012 can all be set as pipes with heating function.

[0110] The mixing head 3 is equipped with a cleaning rod 304 and a control rod 305. The cleaning rod 304 is used to clean the paint residue inside the mixing head 3 (mainly the paint residue in the mixing chamber and the wall of the discharge pipe of the mixing head 3) and to block the discharge port of the mixing head 3 (blocking the discharge port of the mixing head 3 can prevent the plastic substrate from entering the mixing head 3 during injection molding). The control rod 305 is used to block or open the inlet A301, the inlet B302 and the inlet C303.

[0111] When the control lever 305 is in the closed position: material A can circulate in material A tank 101, discharge pipe A1011 and return pipe A1012; material B can circulate in material B tank 102, discharge pipe B1021 and return pipe B1022; and material C can circulate in material C tank 201, discharge pipe C2011 and return pipe C2012.

[0112] As shown in Figures 1, 2, 4, and 5, the main function and role of the mixing head 3 is as follows: Material A and Material B are fed from their respective material tanks to the high-pressure metering pump via the control system of the in-mold coating device 1. Material A and Material B are fed from the corresponding material tanks via the feeding pump to the high-pressure metering pump. Material B and Material C, which are fed from the color paste tank (C material tank 201) via the heating pipe with a pre-set flow rate and ratio, enter the mixing head 3 together. Material A, Material B, and Material C are mixed together in the mixing head 3 in a turbulent manner. After the mixing is completed, the mixture enters the mold through the flow channel and forms a coating layer with a color effect on the surface of the substrate in the mold.

[0113] The main function and role of the cleaning rod 304 is to clean the residual PUR material in the mixing chamber of the in-mold mixing head and the wall of the discharge pipe.

[0114] The control lever 305 is hydraulically controlled for movement. Its function is to circulate the raw material through its return trough. More specifically, the control lever 305 may be equipped with a self-sealing groove. When the mixing head 3 is mixing, the raw material is injected into this self-sealing groove on the control lever 305 for reaction and foaming, thereby sealing the gap between the control lever 305 and the inner wall of the mixing head 3, preventing material leakage.

[0115] In the specific design, a return groove (keyway) is set on the surface of the control rod 305, which facilitates the return of materials A, B, and C from the discharge pipe to the return pipe and the material tank. The circulation of raw materials ensures timely response and operation of the equipment, prevents liquid accumulation, and ensures stable operation of the equipment. At this time, the raw material of the mixing head 3 enters the nozzle of the spray gun through the feed hole of the mixing head 3 and then enters the return groove of the control rod 305.

[0116] In one specific embodiment of this application, the A material tank 101, the B material tank 102 and the C material tank 201 are all connected to a temperature control device 5. The temperature control device 5 includes a water-type raw material temperature controller 501. The water-type raw material temperature controller 501 is connected to a jacketed heat exchanger located outside the A material tank 101 and the B material tank 102 through a water supply pipe. The jacketed heat exchanger is provided with a heat insulation layer on its exterior.

[0117] The temperatures of materials A and B can be indirectly controlled by controlling the water temperature in the jacketed heat exchanger. In specific manufacturing, the water-type raw material temperature controller 501 is equipped with a water storage tank and an electric heater. The control accuracy of the water-type raw material temperature controller 501 is ±1℃. The water-type raw material temperature controller 501 is installed near material tanks A 101, B 102, and C 201. The water-type raw material temperature controller 501 continuously supplies circulating hot water to the jacketed heat exchangers of material tanks A 101, B 102, and C 201. The efficient circulating water temperature control system ensures precise temperature control of the tanks, achieving ±1℃.

[0118] In one specific embodiment of this application, both material tank A 101 and material tank B 102 are connected to a raw material agitator 103, which can continuously or indirectly agitate the materials. Agitation helps maintain the uniformity and temperature stability of materials A and B.

[0119] In one specific embodiment of this application, both material tank A 101 and material tank B 102 are connected to low-pressure feed pumps 104, and the two low-pressure feed pumps 104 are respectively connected to different high-pressure metering pumps through pipelines. In a specific design, the low-pressure feed pumps 104 can be placed below material tank A 101 and material tank B 102 to draw raw materials from the tanks and transport them to the high-pressure metering pump side.

[0120] In one specific embodiment of this application, the high-pressure metering pump is disposed within an insulated enclosure 105, and a volumetric flow meter is also provided within the insulated enclosure 105. The volumetric flow meter is connected to the high-pressure metering pump via a pipeline. The volumetric flow meter can be used to measure the delivery rate of the high-pressure metering pump.

[0121] In one specific embodiment of this application, both material tank A 101 and material tank B 102 are connected to a vacuum generator 106.

[0122] In the specific design, the vacuum generator 106 can be installed on material tank A 101 and material tank B 102 respectively to continuously extract air from the tanks, ensuring that the vacuum degree inside the raw material tanks is less than 0.2 bar (i.e., the air pressure is less than 0.8 bar) and ensuring that as much air as possible is expelled from the raw materials. As shown in Figure 6, installing the vacuum generator 106 on material tank A 101 and material tank B 102 respectively has the following beneficial effects: ① It can solve the problems of bubbles and poor appearance of the polyurethane (PUR) layer on the product surface; ② When adding new materials to material tank A 101 and material tank B 102, the bubbles generated in the tanks can be extracted in a timely and effective manner, thereby ensuring product quality; ③ Integrating the vacuum generator 106 on material tank A 101 and material tank B 102 respectively can effectively reduce the investment in factory space and auxiliary equipment.

[0123] In one specific embodiment of this application, the mixing head 3 is connected to a hydraulic power station 306, and the cleaning rod 304 and the control rod 305 are extended and retracted by hydraulic power provided by the hydraulic power station 306. The main function of the hydraulic power station 306 is to control the opening and closing of the mixing head 3.

[0124] In one specific embodiment of this application, the A material tank 101, the B material tank 102, and the hydraulic power station 306 are all mounted on the bracket 601. The bracket 601 is also equipped with an AB material electrical control cabinet 6011 and an AB material automatic replenishment device 6012.

[0125] The AB material control cabinet 6011 is used to control the main process parameters of raw materials A and B in the equipment, such as flow rate, temperature, ratio, opening time of the mixing head, and injection speed. As shown in Figure 3, the insulation box 105 is mounted on bracket two 602. The integration of equipment on bracket one 601 can greatly reduce the space required for the equipment. By independently mounting the insulation box 105 on bracket two 602, the interference of vibration from equipment on bracket one 601 on the high-pressure metering pump and volumetric flow meter inside the insulation box 105 can be reduced, thereby effectively ensuring processing accuracy.

[0126] In one specific embodiment of this application, the color paste conveying device 2 is mounted on the color paste station bracket.

[0127] The pigment conveying device 2 specifically includes a C-material tank 201, a water-type raw material temperature controller connected to the C-material tank, a pumping piston pump, a volumetric flow meter, and a C-material electrical control cabinet. This application also includes a centralized control system 9, which is used to control the various groups of devices and equipment in this application (including the AB material electrical control cabinet and the C material electrical control cabinet).

[0128] In practical use, material C is set according to the physical property requirements of the customer's materials, and the mixing ratio is set at 1% to 8% of the total volume of materials A, B and C. Material C flows from material C tank 201 through a suction piston pump (the suction piston pump can make the maximum pressure of material C reach 220 bar, which is a high-pressure pump) and flows out from the heating outlet pipe C2011 according to the preset flow rate, pressure (such as 150 bar) and ratio. Materials A and B flow from their respective tanks through the low-pressure feed pump 104 to the high-pressure metering pump and flow out from the heating outlet pipes A1011 and B1021 according to the preset flow rate, pressure (such as 150 bar) and ratio. Materials A, B and C are mixed together in the mixing head 3 in a turbulent manner. After the mixing is completed, the reaction molding coating enters the molding mold 4 through the pipe and forms a PUR polyurethane / PUA polyurea coating layer with color effect on the surface of the substrate in the molding mold 4.

[0129] In one specific embodiment of this application, the environmentally friendly in-mold coating processing equipment for plastic products further includes an injection molding device 7, which is equipped with an automatic plastic feeding device 701, a hopper, and a raw material drying system.

[0130] In one specific embodiment of this application, the mold 4 includes a sliding template and a fixed template;

[0131] The sliding template is provided with two half molds, half mold one and half mold two, and the fixed template is provided with half mold three. Half mold one and half mold two can be switched to dock with half mold three by translation and sliding.

[0132] The semi-mold 3 is connected to the discharge end of the injection molding device 7 and the discharge end of the mixing head 3;

[0133] The first half-mold and the third half-mold are combined to form an injection molded substrate cavity;

[0134] The two semi-molds are combined with the three semi-molds to form a reaction molding coating cavity.

[0135] In one specific embodiment of this application, the forming mold 4 includes a moving template and a front template;

[0136] As shown in Figure 14, the moving template is provided with a rotating mechanism that rotates 360° along the vertical axis, and the moving template is also provided with a horizontal moving mechanism. The moving template includes a first half-mold 401 and a second half-mold 402.

[0137] The front template is provided with a horizontal moving mechanism, and the front template includes a third half-mold 403 and a fourth half-mold 404;

[0138] The third half mold 403 is connected to the discharge end of the injection molding device 7. The first half mold 401 and the second half mold 402 can both be closed with the third half mold 403 to form an injection molding substrate cavity.

[0139] The fourth half-mold 404 is connected to the discharge end of the mixing head 3. The first half-mold 401 and the second half-mold 402 can both be molded together with the fourth half-mold 404 to form a reaction molding coating cavity.

[0140] Taking PUR polyurethane coatings and plastic substrates as examples, in the specific design, ejector pins and venting mechanisms are provided on the first half-mold 401 and the second half-mold 402 of the moving mold, and a PUR polyurethane feed channel is provided on the fourth half-mold 404 of the fixed mold. Preferably, temperature control unit one controls the first half-mold 401, the second half-mold 402 of the moving mold, and the third half-mold 403 of the front mold. Depending on the different specifications of the raw materials, the mold temperature of the first half-mold 401, the second half-mold 402, and the third half-mold 403 is 80℃~110℃. Preferably, mold temperature control unit two controls the fourth half-mold 404 of the front mold, and the mold temperature of the fourth half-mold 404 is 90℃~130℃. Controlling the mold temperature of the moving mold and the front mold can further reduce the adverse effects of mold temperature on PUR polyurethane and the substrate material. Setting the mold temperature of the first half mold 401 and the second half mold 402 of the moving mold and the third half mold 403 of the front mold in the range of 80℃ to 110℃, and the mold temperature of the fourth half mold 404 of the front mold in the range of 90℃ to 130℃, allows the PUR material to react and cure steadily after entering the cavity, without affecting product quality and subsequent processes. When the mold temperature of the fourth half mold 404 is below 90℃ and the mold temperatures of the first half mold 401, the second half mold 402, and the third half mold 403 of the front mold are below 80℃, the PU layer of the product will exhibit defects such as poor curing and insufficient reaction, as shown in Figures 7 and 8. When the temperature of the fourth half mold 404 is higher than 130℃ and the temperatures of the first half mold 401, the second half mold 402, and the front template third half mold 403 are higher than 110℃, the PU layer of the product will experience problems such as difficulty in injection, resulting in material shortage and overall product deformation, as shown in Figures 9 and 10.

[0141] In practical application, taking PUR polyurethane coating and plastic substrate as an example, after the two half-molds of the moving mold platen and the two half-molds of the front mold platen are closed, injection substrate cavity and reaction molding coating cavity (PUR polyurethane cavity) are formed respectively. After the molding mold 4 is closed, injection begins first in the injection substrate cavity formed by the first half-mold 401 of the moving mold platen and the third half-mold 403 of the front mold platen. After the substrate has been injected, pressure-held, filled and cooled, the mold is opened, the moving mold platen rotates 180° to deliver the first half-mold with the injection substrate attached to the fourth half-mold 404, the molding mold 4 is closed again, and the injection substrate cavity formed by the second half-mold 402 of the moving mold platen and the third half-mold 403 of the front mold platen begins to inject plastic, while in the reaction molding coating cavity (PUR polyurethane cavity) formed by the first half-mold 401 and the fourth half-mold 404 of the front mold platen, reaction injection molding (Reaction Injection) occurs. The molding (RIM) equipment begins to inject reactive molding coating (PUR polyurethane). At this time, the injection substrate in the reactive molding coating cavity (PUR polyurethane cavity) can form a high-quality in-mold painted coating product. There is no need to place the injection-molded substrate product into another set of equipment for surface spraying or painting. This application can realize the painting process in the mold, thereby effectively improving production efficiency.

[0142] In one specific embodiment of this application, an automatic part-removing device 801 for removing workpieces from the molding mold 4 is provided on one side of the molding mold 4, and an automatic trimming device 802 for trimming workpieces is provided on one side of the automatic part-removing device 801. Both the automatic part-removing device 801 and the automatic trimming device 802 are installed in the automated isolation guardrail 8.

[0143] In one specific embodiment of this application, the number of C material tanks 201 is two or more.

[0144] Setting the number of C material tanks 201 to two or more takes color switching into account. This application can quickly complete the switching of multiple colors within 5 minutes. As shown in Figure 4, the A and B material components in A material tank 101 and B material tank 102 are kept clean. The color paste is added to the color paste conveying device 2. By switching the C material tank 201 to different colors through the replacement unit of the color paste conveying device 2, the switching of different colors can be completed in about 5 minutes.

[0145] In one specific embodiment of this application, the environmentally friendly in-mold coating processing equipment for plastic products is controlled by digital signal input and output logic, wherein the control logic of the digital signals includes one or more of the following:

[0146] D1. When the environmentally friendly in-mold coating processing equipment for plastic products malfunctions, output a "DO mechanical fault" signal;

[0147] D2. When the first half-mold and the third half-mold are joined to form the injection molding substrate cavity, the "DO cleaning rod advance" signal is output and continues until the "DO ready to foam" signal is output and then the output is disconnected; after the cleaning rod 304 advances to the position, the system outputs the "DI cleaning rod advance to position" signal, and the "DI cleaning rod advance to position" signal is active at a high level.

[0148] The purpose of executing the "cleaning rod advance signal" is to prevent the plastic substrate from entering the injection gun head of the polyurethane equipment during injection molding. In turntable mode (molding mold 4 includes a moving platen and a front platen), there is no need to output the "DO cleaning rod advance" signal. However, in slide table mode (molding mold 4 includes a slide platen and a fixed platen), when half-mold one and half-mold three are joined to form the injection substrate cavity, the "DO cleaning rod advance signal" needs to be output and continues until the "DO ready to foam" signal is output, at which point the output is disconnected. This is because of the different mold structures. In turntable mode, the injection of the substrate and the injection of polyurethane are connected to different half-molds (the third half-mold 403 is connected to the discharge end of the injection molding device 7, and the fourth half-mold 404 is connected to the discharge end of the in-mold coating device 1), so the issue of the substrate entering the polyurethane equipment injection gun head does not need to be considered. The slide table mode is different. In slide table mode, the injection substrate and polyurethane injection share a cavity surface (the half-mold three is connected to the ejector end of the injection molding device 7 and the ejector end of the in-mold coating device 1). Therefore, when the mold is closed and the injection substrate is being injected, it is necessary to prevent the plastic substrate from entering the injection gun head of the polyurethane equipment. Thus, the cleaning rod 304 must be kept in the forward position until the polyurethane injection preparation signal is output. In turntable mode, the "DO cleaning rod forward" signal skips the control process and directly proceeds to the next step.

[0149] A high-level active signal indicates that a high charge will activate the alarm. 0 represents a low level, and 1 represents a high level. 0~14V is low level, and 15~28V is high level. In slide table mode, the IMM (Injection Molding Machine) checks the "DI cleaning rod forward position" signal before injection. If the "DI cleaning rod forward position" signal is lost, the plastic injection action is prohibited, and an alarm "cleaning rod is not in the forward position" is displayed. At this time, it is not necessary to exit automatic mode; simply wait until the "DI cleaning rod forward position" signal is input into the system before continuing plastic injection. Monitoring the position of the cleaning rod 304 in slide table mode is for quality, safety, and equipment stability considerations. Because in slide table mode, substrate injection and polyurethane injection share a cavity surface (half-mold three) on the fixed mold platen (also called the static mold side), it is necessary to ensure that the cleaning rod 304 is in the forward position during substrate injection to prevent substrate from being injected into the polyurethane injection gun head.

[0150] D3. When the environmentally friendly in-mold coating processing equipment for plastic products is in semi-automatic / fully automatic mode, it outputs a "DO automatic operation" signal;

[0151] The difference between semi-automatic and fully automatic environmentally friendly in-mold coating equipment for plastic products is that in semi-automatic mode, after a complete cycle is completed, manual confirmation and pressing the start button are required to execute the next cycle, while in fully automatic mode, after a complete cycle is completed, the next cycle can be executed automatically without manual confirmation.

[0152] D4. When the reaction molding coating cavity is formed after the mold is closed, the "DO prepare to foam" signal is triggered, and the "DO prepare to foam" signal is disconnected before the "DO start foaming" signal is output.

[0153] In the specific design, the "DO Ready to Foam" signal can be set with an output delay time. The task between the "DO Ready to Foam" signal and the "DO Start Foaming" signal is to establish high pressure for the polyurethane, that is, to establish high pressure for polyurethane A and B materials (entering the high-pressure metering pump) in preparation for injection into the molding cavity.

[0154] D5. When the system receives the "DI Ready for Foaming" signal, it outputs the "DO Start Foaming" signal. When the system receives the "DI Foaming Completed" signal, it disconnects the "DO Start Foaming" signal output and enters the foaming cooling timer. The "DI Foaming Completed" signal is active high. The "DI Ready for Foaming" signal is active high; the "DO Start Foaming" signal output is prohibited if a high-level signal is not received. The purpose of the foaming cooling timer is to accurately measure the curing and cooling time of polyurethane to ensure product quality. When the conveying speed of polyurethane material A and material B in the polyurethane equipment reaches the set injection speed, and the system operates at this speed for more than 2 seconds without fluctuation, the system will determine that the polyurethane injection conditions are met and will output the "DI Ready for Foaming" signal.

[0155] D6. When the foaming machine is foaming, the system outputs a "DI is foaming" signal. The "DI is foaming" signal is active at a high level and there is no alarm output.

[0156] D7. The "DO blow cleaning rod" signal is triggered by the "DI foaming complete" signal;

[0157] In the specific design, the "DO blow cleaning rod" signal can be set with a delay time and an output time. After the "DO blow cleaning rod" signal is issued, an air valve at the nozzle of the polyurethane foaming equipment will activate to remove any residual polyurethane material around the cleaning rod 304, preventing defects in the next injection cycle. More specifically, the system does not require a "DO cleaning rod retract" signal. When polyurethane injection foaming occurs, the cleaning rod 304 will automatically retract, and after foaming is complete, the cleaning rod 304 will automatically advance. This program can be set internally by the polyurethane equipment. Setting the delay time is for more precise control of the appropriate blowing timing, and the output time is for precise control of the blowing time.

[0158] D8. When the foaming machine malfunctions, the system outputs a "DI foaming machine malfunction" signal. The "DI foaming machine malfunction" signal is active at a high level. When the "DI foaming machine malfunction" signal is input into the system, the system alarms "foaming machine malfunction" and prohibits the system from entering the automatic mode with "foaming action". If in automatic mode, it will jump to manual mode after the cycle ends.

[0159] The foaming machine specifically includes an in-mold coating device 1, a color paste conveying device 2, a mixing head 3, and other equipment related to polyurethane foaming. The automatic mode here includes the semi-automatic and fully automatic modes mentioned above. The manual mode is the third mode for environmentally friendly in-mold coating processing equipment for plastic products. In this mode, the system does not send control signals to the polyurethane equipment.

[0160] D9. When the downstream equipment of the injection molding machine detects a defective product, it inputs a "DI product defective" signal to the system. The "DI product defective" signal is active high.

[0161] When the system receives a "DI product defective" signal, the IMM injection molding machine system outputs a "DI product defective" signal (scrap signal) to the automated equipment (including automatic part removal device 801, automatic trimming device 802, etc.). In actual use, the polyurethane reaction molding equipment control software can accurately measure whether the weight, time, and speed of the injected polyurethane meet the set requirements. If the measured actual injected polyurethane weight, time, or speed deviates from the actual set value by more than 1%, the polyurethane reaction molding equipment will output a high-level product defective signal to the IMM injection molding machine system. After receiving this signal, the IMM injection molding machine system will automatically output a product defective signal to the automated equipment. Figure 13 shows the logic diagram of the system's handling of defective products in this application.

[0162] Preferably, Figures 11 and 12 are overviews of the I / O signal block diagrams in the turntable and slide modes.

[0163] The above control logic can be flexibly combined with different types of injection molding equipment and mold-making equipment to meet the production needs of different specifications of products, according to the customer's production requirements. The "system" mentioned in the above control logic can be integrated into the centralized control system 9 shown in Figure 2.

[0164] An environmentally friendly in-mold coating process for plastic products, using environmentally friendly in-mold coating equipment, as shown in Figure 14, includes the following steps:

[0165] S01. Mold closing, at this time the first half mold 401 and the third half mold 403 close to form the injection base cavity of the first workpiece, and the injection device 7 injects the first workpiece base into the injection base cavity;

[0166] S02. Keep the mold closed and perform pressure holding and cooling shaping of the first workpiece substrate;

[0167] S03. Mold opening: The first workpiece substrate is attached to the first half mold 401. After the moving mold plate rotates 180°, the mold is closed. At this time, the first half mold 401 and the fourth half mold 404 are closed to form a reaction molding coating cavity containing the first workpiece substrate. The second half mold 402 and the third half mold 403 are closed to form an injection molding substrate cavity for the second workpiece.

[0168] S04. While the mold is closed, the mixing head 3 injects the reactive molding coating onto the surface of the first workpiece substrate, and the injection molding device 7 simultaneously injects the second workpiece substrate.

[0169] S05. While the mold is closed, the reaction molding coating reacts and forms on the surface of the first workpiece substrate, and the pressure holding and cooling of the second workpiece substrate are carried out simultaneously.

[0170] S06. The mold is opened, the first workpiece after coating is attached to the first half mold 401, the second workpiece substrate is attached to the second half mold 402, and the automatic part removal device 801 removes the first workpiece after coating from the first half mold 401.

[0171] S07. After the moving template rotates 180°, the mold is closed. At this time, the second half mold 402 and the fourth half mold 404 are closed to form a reaction molding coating cavity containing the second workpiece substrate. The first half mold 401 and the third half mold 403 are closed to form an injection molding substrate cavity for the third workpiece.

[0172] S08. While the mold is closed, the mixing head 3 injects the reactive molding coating onto the surface of the second workpiece substrate, and the injection molding device 7 simultaneously injects the third workpiece substrate;

[0173] S09. While the mold is closed, the reaction molding coating reacts and forms on the surface of the second workpiece substrate, and the pressure holding and cooling of the third workpiece substrate are carried out simultaneously.

[0174] S010. The mold is opened, the second workpiece after coating is attached to the second half mold 402, the third workpiece substrate is attached to the first half mold 401, and the automatic part removal device 801 removes the second workpiece after coating from the second half mold 402.

[0175] Repeating steps S07-S010 enables continuous and efficient production of environmentally friendly in-mold coating for plastic products.

[0176] S01~S010 are processes where the substrate is molded in one step by injection molding machine and then coated in the mold in one step. In this process, the substrate does not need to be demolded first and then transported to the painting station for painting. This can solve the problems of product deformation and difficulty in secondary positioning at the painting station. The specific implementation can be summarized as follows: The molding mold 4 closes, the thermoplastic substrate is injected first, and after pressure holding, filling and cooling are completed, the molding mold 4 opens, and the turntable is rotated 180° to the operating side to move the injection-molded substrate to another cavity corresponding to the PUR polyurethane. The molding mold 4 closes again. At this time, the system sends a coating start signal, and the coating equipment opens the mixing head to start injecting PUR polyurethane material into the surface of the substrate (at the same time, the injection molding machine injects substrate for the next cycle). After the coating equipment finishes casting, the part in the mold completes the reaction and solidification. After the molding mold 4 opens, the part is ejected, and the automatic part removal device 801 (mechanical gripper) takes out the part.

[0177] In one specific embodiment of this application, the injection molding substrate material of the injection molding device includes one or more of polypropylene, PC, ABS, PC+ABS, PA66 and carbon fiber.

[0178] In one specific embodiment of this application, when the reaction molding coating is polyurethane, and the molding die 4 includes the moving mold plate and the front mold plate, the melting temperature of the barrel of the injection molding device 7 is 200℃~320℃, the mold temperature of the first half mold 401, the second half mold 402 and the third half mold 403 is 80℃~110℃, the mold temperature of the fourth half mold 404 is 90℃~130℃, the temperature at which the polyurethane material enters the reaction molding coating cavity is 60℃~90℃, the working pressure of the polyurethane material entering the reaction molding coating cavity is 11MPa~21MPa, and the curing time of the polyurethane material in the reaction molding coating cavity is 20s~200s.

[0179] In one specific embodiment of this application, the injection molding substrate material is polypropylene, the melting temperature of the barrel of the injection molding device 7 is 170℃~250℃, the injection molding substrate is a polypropylene substrate, and the in-mold coating process of the polypropylene substrate includes the following steps:

[0180] S11. The injection molding device 7 injects polypropylene substrate into the injection molding substrate cavity;

[0181] S12. The injection-molded polypropylene substrate is rotated and sent to the PLASMA surface treatment equipment (model SPA2800) for plasma treatment.

[0182] S13. Inject polyurethane material into a molded surface of a plasma-treated polypropylene substrate;

[0183] S14. Open the mold and remove the part to obtain the finished product in which polypropylene and polyurethane materials are bonded together.

[0184] In one specific embodiment of this application, the technical parameters of the PLASMA surface treatment equipment are: voltage 190V~250V, frequency 40Hz~60Hz, current 0.25A~0.35A, air pressure 0.4bar~0.8bar, and processing width 20~90mm. Preferably, the voltage is 220V, frequency 50Hz, current 0.31A, air pressure 0.6bar, and processing width 75mm.

[0185] In one specific embodiment of this application, the technical parameters of the PLASMA surface treatment equipment are as follows: the height of the plasma from the substrate surface is 8mm~15mm, the plasma moving speed is 50mm / s~150mm / s, and the plasma temperature is 70℃~100℃. Preferably, the height of the plasma from the substrate surface is 10mm, the plasma moving speed is 100mm / s, and the plasma temperature is 90℃.

[0186] In one specific embodiment of this application, the environmentally friendly in-mold coating equipment for plastic products can select from various types of mold microstructures to produce, such as: floral patterns, mirror finishes, genuine leather textures, matte finishes, diamond-cut facets, engraved lettering, and other fine textures, according to customer production needs. In practical implementation, polyurethane, as a "smart" material, possesses properties such as flexibility, wear resistance, scratch resistance, and self-healing. Its colors can be freely combined, resulting in vibrant hues. The unique perfect replicability of polyurethane allows for nearly 99% complete replication of the mold surface texture. To better present the effect and meet actual functional requirements, the mold texture can be applied to the substrate surface or to the PUR polyurethane surface layer. Specific texture effects include the following effects shown in Figure 15:

[0187] A. Genuine leather effect: The texture of genuine leather can be applied to the surface of the substrate or to the surface of PUR polyurethane to achieve a perfect replica effect;

[0188] B. Logo effect: The logo effect texture can be applied to the surface of the substrate or to the surface of PUR polyurethane to achieve a perfect replication effect;

[0189] C. Smart membrane effect: Smart membranes can be embedded using IMD, IML and IMR processes to achieve smart surface effects;

[0190] D. Multiple texture effects: Weave textures, diagonal textures, wave textures, and other texture effects shown in Figure 15 (D) can be applied to the substrate surface or to the PUR polyurethane surface layer to achieve a perfect replication effect.

[0191] E. Diamond-cut facet effect: The diamond-cut facet effect and other textures shown in E of Figure 15 can be applied to the substrate surface or to the PUR polyurethane surface layer to achieve a perfect replica effect.

[0192] F. Wood grain texture effect: Wood grain texture effect and other texture effects shown in F in Figure 15 can be embedded using IMD, IML and IMR processes to achieve a high-end sensory effect of wood grain; the texture in the wood grain texture effect is attached to the surface of the substrate, and the texture surface layer is a PUR polyurethane surface layer.

[0193] In one specific embodiment of this application, the environmentally friendly in-mold coating equipment for plastic products can be flexibly combined with the following different types of injection molding machines according to customer production needs:

[0194] As shown in Figure 16, environmentally friendly in-mold coating equipment for plastic products can be paired with electric injection molding machines with clamping forces ranging from 50 tons to 450 tons or even larger, thereby meeting the in-mold coating process requirements for precision small-weight products weighing 30g to 450g.

[0195] As shown in Figure 17, environmentally friendly in-mold coating equipment for plastic products can be paired with hydraulic injection molding machines with clamping forces ranging from 450 tons to 5500 tons or even larger, to meet the in-mold coating process requirements of products weighing 500g to 3000g or even larger.

[0196] As shown in Figure 18, environmentally friendly in-mold coating equipment for plastic products can be paired with injection molding machines with clamping forces ranging from 450 tons to 5500 tons or even greater, whether they are multi-shot or multi-component injection molding machines, to meet the in-mold coating process requirements of products weighing 500g to 4000g or even larger.

[0197] As shown in Figure 19, environmentally friendly in-mold coating equipment for plastic products can be paired with mold-turning frame equipment with clamping forces ranging from 50 tons to 1300 tons or even greater, to meet the in-mold coating process requirements of products in different application scenarios.

[0198] In summary, the environmentally friendly in-mold coating equipment for plastic products of this application has a high degree of integration, which can reduce processing steps. The equipment is stable, flexible and convenient to operate, and can obtain high-quality product surfaces with a variety of color effects. It can be flexibly matched with different types of injection molding machines and mold-changing equipment according to customer production needs, and can meet the production needs of customers in different application scenarios.

[0199] It should be noted that the terminology used in this application is for the purpose of describing specific embodiments only and is not intended to limit the scope of this application. As shown in this specification, unless the context clearly indicates otherwise, words such as "a," "an," "an," and / or "the" do not specifically refer to the singular and may include the plural. The terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising an..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element.

[0200] It should also be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application 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 on this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," "linked," etc., 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; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0201] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of this application.

[0202] Furthermore, it should be noted that the shapes and names of the parts and components described in the specific embodiments described in this specification may differ. All equivalent or simple variations made to the structure, features, and principles described in this application are included within the scope of protection of this application. Those skilled in the art to which this application pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, as long as they do not deviate from the structure of this application or exceed the scope defined by the claims, all of which should fall within the scope of protection of this application.

Claims

1. An environmentally friendly in-mold coating processing equipment for plastic products, comprising an in-mold coating device (1), a color paste conveying device (2), a mixing head (3), and a molding die (4), characterized in that, The in-mold coating device (1) includes an A material tank (101) for supplying material A and a B material tank (102) for supplying material B. The color paste conveying device (2) includes a C material tank (201) for supplying material C. The material A, the material B and the material C are mixed inside the mixing head (3) to form a reaction molding coating. The discharge end of the mixing head (3) is connected to the coating feed end of the molding mold (4). The A material tank (101) is connected to the inlet A (301) of the mixing head (3) through the discharge pipe A (1011) and the return pipe A (1012); The B material tank (102) is connected to the inlet B (302) of the mixing head (3) through the discharge pipe B (1021) and the return pipe B (1022); The C material tank (201) is connected to the inlet C (303) of the mixing head (3) through the discharge pipe C (2011) and the return pipe C (2012); The mixing head (3) is provided with a cleaning rod (304) and a control rod (305). The cleaning rod (304) is used to clean the paint residue in the mixing head (3) and block the outlet of the mixing head (3). The control rod (305) is used to block or open the inlet A (301), the inlet B (302) and the inlet C (303). When the control lever (305) is in the closed position: material A can circulate in material A tank (101), discharge pipe A (1011) and return pipe A (1012), material B can circulate in material B tank (102), discharge pipe B (1021) and return pipe B (1022), and material C can circulate in material C tank (201), discharge pipe C (2011) and return pipe C (2012).

2. The environmentally friendly in-mold coating equipment for plastic products according to claim 1, characterized in that, The A material tank (101), the B material tank (102) and the C material tank (201) are all connected to a temperature control device (5). The temperature control device (5) includes a water-type raw material temperature controller (501). The water-type raw material temperature controller (501) is connected to a jacketed heat exchanger located outside the A material tank (101) and the B material tank (102) through a water supply pipe. The jacketed heat exchanger is provided with a heat insulation layer on the outside.

3. The environmentally friendly in-mold coating equipment for plastic products according to claim 2, characterized in that, Both the A material tank (101) and the B material tank (102) are connected to a raw material agitator (103), which can continuously or indirectly agitate the raw material.

4. The environmentally friendly in-mold coating equipment for plastic products according to claim 3, characterized in that, Both the A material tank (101) and the B material tank (102) are connected to a low-pressure feed pump (104), and the two low-pressure feed pumps (104) are respectively connected to different high-pressure metering pumps through pipelines.

5. The environmentally friendly in-mold coating equipment for plastic products according to claim 4, characterized in that, The high-pressure metering pump is installed inside the insulation box (105), and the insulation box (105) is also equipped with a volumetric flow meter, which is connected to the high-pressure metering pump through a pipeline.

6. The environmentally friendly in-mold coating equipment for plastic products according to claim 5, characterized in that, Both tank A (101) and tank B (102) are connected to a vacuum generator (106).

7. The environmentally friendly in-mold coating equipment for plastic products according to claim 6, characterized in that, The mixing head (3) is connected to the hydraulic power station (306), and the cleaning rod (304) and the control rod (305) are extended and retracted by the hydraulic power provided by the hydraulic power station (306).

8. The environmentally friendly in-mold coating equipment for plastic products according to claim 7, characterized in that, The A material tank (101), the B material tank (102), and the hydraulic power station (306) are all installed on the bracket (601). The bracket (601) is also equipped with an AB material electrical control cabinet (6011) and an AB material automatic replenishment device (6012).

9. The environmentally friendly in-mold coating equipment for plastic products according to claim 8, characterized in that, The pigment conveying device (2) is installed on the pigment station bracket.

10. The environmentally friendly in-mold coating equipment for plastic products according to claim 9, characterized in that, The environmentally friendly in-mold coating processing equipment for plastic products also includes an injection molding device (7), which is equipped with an automatic plastic feeding device (701), a hopper, and a raw material drying system.

11. The environmentally friendly in-mold coating equipment for plastic products according to claim 10, characterized in that, The mold (4) being formed includes a slide plate and a fixed plate; The sliding template is provided with two half molds, half mold one and half mold two, and the fixed template is provided with half mold three. Half mold one and half mold two can be switched to dock with half mold three by translation and sliding. The semi-mold is connected to the discharge end of the injection molding device (7) and the discharge end of the mixing head (3); The first half-mold and the third half-mold are combined to form an injection molded substrate cavity; The two semi-molds are combined with the three semi-molds to form a reaction molding coating cavity.

12. The environmentally friendly in-mold coating equipment for plastic products according to claim 10, characterized in that, The mold (4) being formed includes a moving mold plate and a front mold plate; The moving template is provided with a rotating mechanism that can rotate 360° along the vertical axis, and the moving template is also provided with a horizontal moving mechanism. The moving template includes a first half-mold (401) and a second half-mold (402). The front template is provided with a horizontal moving mechanism, and the front template includes a third half-mold (403) and a fourth half-mold (404). The third half mold (403) is connected to the discharge end of the injection molding device (7). The first half mold (401) and the second half mold (402) can both be closed with the third half mold (403) to form an injection molding substrate cavity. The fourth half mold (404) is connected to the discharge end of the mixing head (3). The first half mold (401) and the second half mold (402) can both be molded together with the fourth half mold (404) to form a reaction molding coating cavity.

13. The environmentally friendly in-mold coating equipment for plastic products according to claim 12, characterized in that, The forming mold (4) is provided with an automatic part-removing device (801) for removing workpieces from the forming mold (4) on one side, and an automatic trimming device (802) for trimming workpieces is provided on one side of the automatic part-removing device (801). Both the automatic part-removing device (801) and the automatic trimming device (802) are installed in the automated isolation guardrail (8).

14. The environmentally friendly in-mold coating equipment for plastic products according to any one of claims 1 to 12, characterized in that, The number of the C material tanks (201) is two or more.

15. The environmentally friendly in-mold coating equipment for plastic products according to any one of claims 10 to 12, characterized in that, The environmentally friendly in-mold coating equipment for plastic products is controlled by digital signal input and output logic, wherein the control logic of the digital signals includes one or more of the following: D1. When the environmentally friendly in-mold coating processing equipment for plastic products malfunctions, output a "DO mechanical fault" signal; D2. When the first half-mold and the third half-mold are joined to form the injection molding substrate cavity, the "DO cleaning rod advance" signal is output and continues until the "DO ready to foam" signal is output and then the output is disconnected; after the cleaning rod advances to the position, the system outputs the "DI cleaning rod advance to position" signal, and the "DI cleaning rod advance to position" signal is active high. D3. When the environmentally friendly in-mold coating processing equipment for plastic products is in semi-automatic / fully automatic mode, it outputs a "DO automatic operation" signal; D4. When the reaction molding coating cavity is formed after the mold is closed, the "DO prepare to foam" signal is triggered, and the "DO start foaming" signal is disconnected before the "DO start foaming" signal is output. D5. When the system receives the "DI ready to foam" signal, it outputs the "DO start foaming" signal; when the system receives the "DI foaming complete" signal, it disconnects the "DO start foaming" signal output and enters the foaming and cooling timer. The "DI foaming complete" signal is active high. The "DI ready to foam" signal is active high, and the "DO start foaming" signal output is prohibited if a high-level signal is not received. The "DI foaming complete" signal is active high. D6. When the foaming machine is foaming, the system outputs a "DI is foaming" signal. The "DI is foaming" signal is active at a high level and there is no alarm output. D7. The "DO blow cleaning rod" signal is triggered by the "DI foaming complete" signal; D8. When the foaming machine malfunctions, the system outputs a "DI foaming machine malfunction" signal. The "DI foaming machine malfunction" signal is active at a high level. When the "DI foaming machine malfunction" signal is input into the system, the system alarms "foaming machine malfunction" and prohibits the system from entering the automatic mode with "foaming action". If in automatic mode, it will jump to manual mode after the cycle ends. D9. When the downstream equipment of the injection molding machine detects a defective product, it inputs a "DI product defective" signal to the system. The "DI product defective" signal is active high.

16. An environmentally friendly in-mold coating process for plastic products, employing the environmentally friendly in-mold coating equipment for plastic products as described in claim 13, characterized in that, Includes the following steps: S01. Mold closing, at this time the first half mold (401) and the third half mold (403) are closed to form the injection base cavity of the first workpiece, and the injection device (7) injects the first workpiece base into the injection base cavity; S02. Keep the mold closed and perform pressure holding and cooling shaping of the first workpiece substrate; S03. Mold opening: The first workpiece substrate is attached to the first half mold (401). After the moving mold plate rotates 180°, the mold is closed. At this time, the first half mold (401) and the fourth half mold (404) are closed to form a reaction molding coating cavity containing the first workpiece substrate. The second half mold (402) and the third half mold (403) are closed to form an injection molding substrate cavity for the second workpiece. S04. While the mold is closed, the mixing head (3) injects the reactive molding coating onto the surface of the first workpiece substrate, and the injection device (7) simultaneously injects the second workpiece substrate. S05. While the mold is closed, the reaction molding coating reacts and forms on the surface of the first workpiece substrate, and the pressure holding and cooling of the second workpiece substrate are carried out simultaneously. S06. The mold is opened, the first workpiece after coating is attached to the first half mold (401), the second workpiece substrate is attached to the second half mold (402), and the automatic part removal device (801) removes the first workpiece after coating from the first half mold (401); S07. After the moving template rotates 180°, the mold is closed. At this time, the second half mold (402) and the fourth half mold (404) are closed to form a reaction molding coating cavity containing the second workpiece substrate. The first half mold (401) and the third half mold (403) are closed to form the injection molding substrate cavity of the third workpiece. S08. While the mold is closed, the mixing head (3) injects the reactive molding coating onto the surface of the second workpiece substrate, and the injection device (7) simultaneously injects the third workpiece substrate. S09. While the mold is closed, the reaction molding coating reacts and forms on the surface of the second workpiece substrate, and the pressure holding and cooling of the third workpiece substrate are carried out simultaneously. S010. The mold is opened, the second workpiece with the coating completed is attached to the second half mold (402), the third workpiece substrate is attached to the first half mold (401), and the automatic part removal device (801) removes the second workpiece with the coating completed from the second half mold (402).

17. The environmentally friendly in-mold coating process for plastic products according to claim 16, characterized in that, The injection molding substrate material of the injection molding device includes one or more of polypropylene, PC, ABS, PC+ABS, PA66 and carbon fiber.

18. The environmentally friendly in-mold coating process for plastic products according to claim 17, characterized in that, When the reaction molding coating is polyurethane, and the molding die (4) includes the moving mold plate and the front mold plate, the melting temperature of the barrel of the injection molding device (7) is 200℃~320℃, the mold temperature of the first half mold (401), the second half mold (402) and the third half mold (403) is 80℃~110℃, the mold temperature of the fourth half mold (404) is 90℃~130℃, the temperature of the polyurethane material entering the reaction molding coating cavity is 60℃~90℃, the working pressure of the polyurethane material entering the reaction molding coating cavity is 11MPa~21MPa, and the curing time of the polyurethane material in the reaction molding coating cavity is 20s~200s.

19. The environmentally friendly in-mold coating process for plastic products according to claim 18, characterized in that, The injection molding substrate material is polypropylene, the melting temperature of the barrel of the injection molding device (7) is 170℃~250℃, the injection molding substrate is a polypropylene substrate, and the in-mold coating process of the polypropylene substrate includes the following steps: S11. The injection molding device (7) injects polypropylene substrate into the injection molding substrate cavity; S12. The injection-molded polypropylene substrate is rotated and sent to the PLASMA surface treatment equipment (model SPA2800) for plasma treatment. S13. Inject polyurethane material into a molded surface of a plasma-treated polypropylene substrate; S14. Open the mold and remove the part to obtain the finished product in which polypropylene and polyurethane materials are bonded together.

20. The environmentally friendly in-mold coating process for plastic products according to claim 19, characterized in that, The technical parameters of the PLASMA surface treatment equipment are: voltage 190V~250V, frequency 40Hz~60Hz, current 0.25A~0.35A, air pressure 0.4bar~0.8bar, and processing width 20~90mm.

21. The environmentally friendly in-mold coating process for plastic products according to claim 20, characterized in that, The technical parameters of the PLASMA surface treatment equipment are as follows: the height of the plasma from the substrate surface is 8mm~15mm, the plasma moving speed is 50mm / s~150mm / s, and the plasma temperature is 70℃~100℃.

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