An Environmentally Friendly In-Mold Coating Processing Equipment and Process for Plastic Products

Abstract

The present invention discloses an environmentally friendly in-mold coating processing device for plastic products, which 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 A material and a B material tank for supplying B material. The color paste conveying device includes a C material tank for supplying C material. The A material, the B material, and the C material are mixed into a reaction molding coating inside the mixing head, and the discharging end of the mixing head is connected to the coating feeding end of the molding die. The environmentally friendly in-mold coating processing device for plastic products of the present invention has a high degree of equipment integration, can reduce processing procedures, is stable in equipment, flexible and convenient to operate, can obtain a high-quality product surface with various color effects, can be freely matched with different types of injection molding machines and mold turning die sets according to the production needs of customers, and can meet the production needs of customers in different application scenarios.

Description

Technical Field

[0001] The present invention relates to the technical field of plastic molding, and particularly to an environmentally friendly in-mold coating processing device and process for plastic products. Background Art

[0002] The spray painting process is mostly used for the coating operation of plastic products. When the existing spray painting devices are in use, the spraying range is mostly limited due to the relatively fixed spray heads, and the surface of the plastic products cannot be completely covered, which easily leads to the problem of uneven spraying, resulting in poor paint spraying effect and low yield. During the spraying process, the paint scattered on the workbench or in the workshop will seriously pollute the workshop environment and is not easy to clean. For high-end plastic products, the manufacturing process usually requires multiple processes, resulting in low processing efficiency.

[0003] The prior art has made improvements to the defects of poor finished product quality and environmental pollution in the spray painting process. For example, a spray painting device for the production and processing of automobile grilles disclosed in Chinese Patent CN213222874U: The horizontal position, height and rotation of the spray head are adjusted through the mutual cooperation between components such as the first electric telescopic rod, motor, third gear, second electric telescopic rod, square rod and working arm, and the scattered paint is collected through the storage box and groove, solving the problems that the existing spray painting devices are prone to uneven spraying and the paint scattered on the workbench or in the workshop during the spraying process seriously pollutes the workshop environment and is not easy to clean. However, there are still cumulative errors in the process of adjusting the components of the spray painting device in the technical solution disclosed in CN213222874U, and there will be deviations in the thickness and accuracy of the spray paint, thus affecting the quality of the product spray paint; the above technical solution only adds a storage box and a groove, and only collects the scattered paint, without fundamentally solving the pollution source in the workshop.

[0004] The in-mold injection surface decoration process is mainly applied to the surface decoration and functional panels of the interior and exterior of automobiles and household appliances. Since large films are prone to local rupture or deformation during the deep cavity or profiling process, and the shape and position accuracy of the surface patterns or characters are relatively low, it is more difficult to apply to large, deep cavity, profiled parts (such as the panels of notebook computers, interior parts of automobiles, etc.). Since it is difficult to position and operate large films in the mold, a large amount of debugging time is required, resulting in low production efficiency and limited application scenarios.

[0005] The prior art has made improvements to the defect that the in-mold injection surface decoration processing technology is difficult to be applied to large films. For example, a polycarbonate substrate for in-mold decoration and its preparation method disclosed in Chinese Patent CN108727797A: By blending branched polycarbonate with copolyester, the thermal tensile deformation amount and puncture resistance strength of polycarbonate are improved, realizing the application of polycarbonate films on large deep cavities and shaped parts. However, in the process of installing the polycarbonate film in the technical solution disclosed in CN108727797A, there will still be positioning errors due to the need for installation positioning; the substrate of the above technical solution is limited to a modified and optimized polycarbonate material, and the selection of product substrates has limitations; in the forming process of the large film in the above technical solution, it is easy to be locally cracked or deformed, resulting in low shape and position accuracy and blurriness of the patterns and characters on the product surface.

[0006] The reaction injection in-mold coating processing technology can, to a certain extent, overcome the deficiencies in the finished product quality, environmental pollution, and difficulty in applying to large films in the spray painting processing technology and the in-mold injection surface decoration processing technology. Usually, a blank product (substrate product) is first injection molded, and then the blank product is sent to the second PU layer process for processing through a transportation and transfer method.

[0007] The in-mold coating processing technology of the prior art, such as a multi-material injection molding machine and its multi-material injection molding method disclosed in Chinese Patent CN110978387A: During processing, the first mold closing injects the injection molded part a; the first mold opening moves the injection molded part a to the first PU fixed mold base; the second mold closing performs PU layer injection molding on the injection molded part a and injects the injection molded part b; the second mold opening moves the injection molded part b to the second PU fixed mold base; the third mold closing performs PU layer injection molding on the injection molded part b and injects the injection molded part a'; the third mold opening takes out the injection molded part a from the first PU fixed mold base and moves the injection molded part a' to the first PU fixed mold base. In the process of coating the polyurethane coating on the surface of the injection molded substrate in the technical solution disclosed in CN110978387A, it is necessary to transfer the position of the injection molded substrate from the original position A to position B, and switch from one fixed mold cavity to another fixed mold cavity. There is a process of alternating the substrates in the middle. Due to the need for secondary positioning of the product, there will be positioning errors; the polyurethane pouring equipment is connected to the polyurethane fixed mold base and arranged on the front template. The injection molded parts need to be clamped by fixtures on the fixed mold base, and tooling fixtures need to be set on the mold; the many process links of the process lead to complex equipment operation and low production efficiency; this solution requires connecting the PU fixed mold base to a compressed air source, and the compressed air source is used to pass compressed air through the PU fixed mold. In order to ensure the forming effect of the PU layer in the PU fixed mold base, before injecting PU, it is necessary to first inject compressed air into the PU fixed mold base. This solution will increase the production time and affect the efficiency, as well as increase the investment in auxiliary equipment for vacuum pumping and passing compressed air. In addition, the technical solution disclosed in CN110978387A requires connecting the PU fixed mold base to a compressed air source, and the compressed air source is used to pass compressed air through the PU fixed mold. In order to ensure the forming effect of the PU layer in the PU fixed mold base, before injecting PU, it is necessary to first inject compressed air into the PU fixed mold base. This solution will increase the production time and affect the efficiency, as well as increase the investment in auxiliary equipment for vacuum pumping and passing compressed air.

[0008] The in-mold coating processing technology of the prior art also has the problem of a single color of the PU surface layer. There are few product colors available for customers to choose from. Adding color paste to the PU material tank will cause a large amount of time to be spent during subsequent color switching, which affects production efficiency.

[0009] In summary, although the in-mold coating processing technology in the prior art can overcome some technical defects of the spray painting processing technology and the in-mold injection molding surface decoration processing technology, it still has defects such as cumbersome production processes, low efficiency, more production equipment and auxiliary machines invested, occupying a large amount of factory space, high input costs, and single product colors. Summary of the Invention

[0010] In order to solve one or more technical problems in the prior art, the present invention provides an environmentally friendly in-mold coating processing equipment for plastic products.

[0011] An environmentally friendly in-mold coating processing device for plastic products, comprising 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 A material and a B material tank for supplying B material. The color paste conveying device includes a C material tank for supplying C material. The A material, the B material, and the C material are mixed into a reaction molding coating inside the mixing head. The discharging end of the mixing head is connected to the coating feeding end of the molding die;

[0012] The A material tank is connected to the feeding port A of the mixing head through a discharging pipe A and a reflux pipe A;

[0013] The B material tank is connected to the feeding port B of the mixing head through a discharging pipe B and a reflux pipe B;

[0014] The C material tank is connected to the feeding port C of the mixing head through a discharging pipe C and a reflux pipe C;

[0015] The mixing head is provided with a cleaning rod and a control rod. The cleaning rod is used to clean the residual coating material in the mixing head and block the discharging port of the mixing head. The control rod is used to block or open the feeding port A, the feeding port B, and the feeding port C;

[0016] When the control rod is in the closed position: The A material can circulate in the A material tank, the discharging pipe A, and the reflux pipe A. The B material can circulate in the B material tank, the discharging pipe B, and the reflux pipe B. The C material can circulate in the C material tank, the discharging pipe C, and the reflux pipe C.

[0017] Preferably, the A material tank, the B material tank, and the C material tank are all connected with temperature control devices. The temperature control devices include water-type raw material temperature control machines. The water-type raw material temperature control machines are communicated with jacket-type heat exchangers arranged outside the A material tank and the B material tank through water conveying pipelines. An insulating and heat-preserving layer is arranged outside the jacket-type heat exchangers.

[0018] Preferably, the A material tank and the B material tank are both connected with raw material stirrers, and the raw material stirrers can stir continuously or indirectly.

[0019] Preferably, the A material tank and the B material tank are both connected with low-pressure feeding pumps, and the two low-pressure feeding pumps are respectively connected with different high-pressure metering pumps through pipelines.

[0020] Preferably, the high-pressure metering pumps are arranged in a heat-insulating box body, and a volume flowmeter is also arranged in the heat-insulating box body. The volume flowmeter is connected with the high-pressure metering pumps through pipelines.

[0021] Preferably, the A material tank and the B material tank are both connected with vacuum generators.

[0022] Preferably, the mixing head is connected to a hydraulic power station, and the cleaning rod and the control rod are telescopically advanced by the hydraulic power provided by the hydraulic power station.

[0023] Preferably, the A material tank, the B material tank, and the hydraulic power station are all installed on the first bracket, and an AB material electric control cabinet and an AB material automatic feeding device are also provided on the first bracket.

[0024] Preferably, the color paste conveying device is arranged on the color paste station bracket.

[0025] Preferably, the environmentally friendly in-mold coating processing equipment for plastic products further includes an injection molding device, and the injection molding device is provided with a plastic automatic feeding device, a hopper, and a raw material drying system.

[0026] Preferably, the forming mold includes a sliding table template and a fixed template;

[0027] Two half molds, namely a first half mold and a second half mold, are provided on the sliding table template, a third half mold is provided on the fixed template, and the first half mold and the second half mold can be switched to dock with the third half mold by translational sliding;

[0028] The third half mold is connected to the discharge end of the injection molding device and the discharge end of the mixing head;

[0029] An injection molding base material cavity is formed after the first half mold and the third half mold are clamped;

[0030] A reaction molding coating cavity is formed after the second half mold and the third half mold are clamped.

[0031] Preferably, the forming mold includes a moving template and a front template;

[0032] The moving template is provided with a rotating mechanism that rotates 360° around an axis in the vertical direction, the moving template is further provided with a horizontal moving mechanism, and the moving template includes a first half mold and a second half mold;

[0033] The front template is provided with a horizontal moving mechanism, and the front template includes a third half mold and a fourth half mold;

[0034] The third half mold is connected to the discharge end of the injection molding device, and an injection molding base material cavity can be formed after the first half mold and the second half mold are both clamped with the third half mold;

[0035] The fourth half mold is connected to the discharge end of the mixing head, and a reaction molding coating cavity can be formed after the first half mold and the second half mold are both clamped with the fourth half mold.

[0036] Preferably, an automatic workpiece taking device for taking out the workpiece from the forming mold is provided on one side of the forming mold, and an automatic edge trimming device for trimming the workpiece is provided on one side of the automatic workpiece taking device. Both the automatic workpiece taking device and the automatic edge trimming device are arranged in an automatic isolation guardrail.

[0037] Preferably, the number of the C material tanks is more than two.

[0038] Preferably, the environmentally friendly in-mold coating processing equipment for plastic products is controlled by the input and output logic of digital signals. The control logic of the digital signals includes one or more of the following:

[0039] D1. When a fault occurs in the environmentally friendly in-mold coating processing equipment for plastic products, an "DO mechanical fault" signal is output.

[0040] D2. When the injection molding substrate cavity is formed after the first half mold and the third half mold are clamped together, an "DO cleaning rod forward" signal is output and remains output until it is disconnected before the "DO ready to foam" signal is output; after the cleaning rod moves forward in place, the system outputs a "DI cleaning rod forward in place" signal, and the "DI cleaning rod forward in place" signal is valid at high level.

[0041] D3. When the environmentally friendly in-mold coating processing equipment for plastic products is in semi-automatic / full-automatic mode, an "DO automatic operation" signal is output.

[0042] D4. When the reaction injection molding coating cavity is formed after clamping, the "DO ready to foam" signal is triggered and the "DO ready to foam" signal is disconnected before the "DO start foaming" signal is output.

[0043] D5. When the system receives the "DI ready to foam" signal, the "DO start foaming" signal is output; when the system receives the "DI foaming completed" signal, the output of the "DO start foaming" signal is disconnected and the foaming cooling timing is entered. The "DI foaming completed" signal is valid at high level; the "DI ready to foam" signal is valid at high level, and the output of the "DO start foaming" signal is prohibited without a high-level signal; the "DI foaming completed" signal is valid at high level.

[0044] D6. When the foaming machine is foaming, the system outputs a "DI foaming" signal, and the "DI foaming" signal is valid at high level without alarm output.

[0045] D7. The "DO blow cleaning rod" signal is triggered by the "DI foaming completed" signal.

[0046] D8. When a fault occurs in the foaming machine, the system outputs a "DI foaming machine fault" signal. The "DI foaming machine fault" signal is active high. When the "DI foaming machine fault" signal is input into the system, the system alarms "foaming machine fault", the system prohibits entering the automatic mode with "foaming action". If in the automatic mode, it jumps to the manual mode after the cycle ends.

[0047] D9. When the downstream equipment of the injection molding machine detects unqualified products, it inputs a "DI product unqualified" signal into the system. The "DI product unqualified" signal is active high.

[0048] To solve one or more technical problems in the prior art, the present invention also provides an environmentally friendly in-mold coating processing technology for plastic products.

[0049] An environmentally friendly in-mold coating processing technology for plastic products, the environmentally friendly in-mold coating processing equipment for plastic products, includes the following steps:

[0050] S01. Close the mold. At this time, the first half mold and the third half mold are closed to form the injection molding substrate cavity of the first workpiece, and the injection molding device injects the substrate of the first workpiece into the injection molding substrate cavity.

[0051] S02. Keep the mold closed, and perform pressure holding and cooling and shaping of the substrate of the first workpiece.

[0052] S03. Open the mold. The substrate of the first workpiece adheres to the first half mold. After the moving template rotates 180°, the mold is closed. At this time, the first half mold and the fourth half mold are closed to form the reaction molding coating cavity with the substrate of the first workpiece inside, and the second half mold and the third half mold are closed to form the injection molding substrate cavity of the second workpiece.

[0053] S04. Keep the mold closed. While the mixing head injects the reaction molding coating onto the surface of the substrate of the first workpiece, the injection molding device synchronously injects the substrate of the second workpiece.

[0054] S05. Keep the mold closed. While the reaction molding coating reacts and forms on the surface of the substrate of the first workpiece, the pressure holding and cooling and shaping of the substrate of the second workpiece are carried out synchronously.

[0055] S06. Open the mold. The first workpiece with coating adheres to the first half mold, the substrate of the second workpiece adheres to the second half mold, and the automatic workpiece taking device takes out the first workpiece with coating from the first half mold.

[0056] 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 the reaction molding coating cavity with the substrate of the second workpiece inside, and the first half mold and the third half mold are closed to form the injection molding substrate cavity of the third workpiece.

[0057] S08. Keep the mold closed. While the mixing head injects the reaction molding coating onto the surface of the second workpiece substrate, the injection molding device simultaneously injects the third workpiece substrate.

[0058] S09. Keep the mold closed. While the reaction molding coating reacts and forms on the surface of the second workpiece substrate, the pressure holding and cooling and shaping of the third workpiece substrate are carried out synchronously.

[0059] S010. Open the mold. The second workpiece completed with coating adheres to the second half - mold, the third workpiece substrate adheres to the first half - mold, and the automatic workpiece taking device takes out the second workpiece completed with coating from the second half - mold.

[0060] 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.

[0061] Preferably, when the reaction molding coating is polyurethane and the molding die includes the moving template and the front template, the melting temperature of the barrel of the injection molding device is 200°C - 320°C, the mold temperature of the first half - mold, the second half - mold, and the third half - mold is 80°C - 110°C, the mold temperature of the fourth half - mold is 90°C - 130°C, the temperature of the polyurethane material entering the reaction molding coating cavity is 60°C - 90°C, 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.

[0062] Preferably, the injection molding substrate material is polypropylene, the melting temperature of the barrel of the injection molding device is 170°C - 250°C, the injection molding substrate is a polypropylene substrate, and the in - mold coating process of the polypropylene substrate includes the following steps:

[0063] S11. The injection molding device injects the polypropylene substrate into the injection molding substrate cavity.

[0064] S12. Rotate the completed injection - molded polypropylene substrate through a turntable and send it to a PLASMA surface treatment device of model SPA2800 for plasma treatment.

[0065] S13. Close the mold and inject the polyurethane material onto the surface of the plasma - treated polypropylene substrate.

[0066] S14. Open the mold and take out the finished product with the polypropylene and the polyurethane material bonded together.

[0067] 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 treatment width 20 - 90mm.

[0068] Preferably, the voltage is 220V, the frequency is 50HZ, the current is 0.31A, the air pressure is 0.6bar, and the treatment width is 75mm.

[0069] Preferably, the technical parameters of the PLASMA surface treatment equipment are that the height of the plasma from the surface of the substrate is 8mm - 15mm, the moving speed of the plasma is 50mm / s - 150mm / s, and the plasma temperature is 70°C - 100°C.

[0070] Preferably, the height of the plasma from the surface of the substrate is 10mm, the moving speed of the plasma is 100mm / s, and the plasma temperature is 90°C.

[0071] Advantages of the present invention:

[0072] (1) The present invention can solve the technical problem of low production efficiency caused by the cumbersome process technology and equipment in the prior art:

[0073] Chinese Patent CN117382096A discloses the application of the in - mold painting and injection - molding process of PUR film in the production of interior car lights. It mentions that there are 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 give any inspiration for setting up a color paste conveying device. That is, those skilled in the art can only think of adding color paste pigments in tank A or tank B according to this patent scheme. When switching colors, tank A or tank B needs to be cleaned, which is a cumbersome and inefficient process and will cause material waste. However, in this patent, by setting up a color paste conveying device and setting the number of tank C to more than two, rapid switching of the color of the reaction - forming coating can be achieved by switching the connection between the feed port C and different tank C, and there is no need to clean the tank, with high production efficiency, environmental protection, and economy.

[0074] Chinese Patent CN114147915A discloses an in - mold spraying system and its process method. In this patent, the mold moves left and right, that is, first injects the substrate, then moves the mold to the PU cavity for painting, and after painting, opens the mold and moves to the substrate cavity to inject the substrate, and only one single cavity can be produced each time. Based on the processing process steps S01 - S010 provided by this patent, the produced substrate can be moved to the PU cavity first, painted, and at the same time, the injection of the substrate can be completed synchronously on the other side, and the production can be cycled alternately all the time, with a substantial improvement in efficiency.

[0075] The conventional processing method in the prior art is to first injection mold the raw material (substrate) product and then transport and transfer the substrate to in-mold coating. This method has cumbersome processes, resulting in low production efficiency and large product positioning errors. By combining a reaction molding device and an injection molding device, the present invention can effectively reduce the in-mold painting process, complete the painting process in one go without demolding the product in the mold, and can solve the problems of product deformation and positioning difficulties.

[0076] (2) The present invention can solve the technical problems of the prior art equipment occupying a large factory building space, low equipment system integration, and the need to invest in more auxiliary equipment:

[0077] In the prior art, the heating device, electrical control cabinet, material tank, and vacuum pumping system device are dispersed. The equipment and system in the present invention have a high integration degree, which can effectively reduce the occupied space. In the traditional two-step painting process, a large number of auxiliary equipment are invested. This patent is applicable to the one-step painting process, which can reduce the investment in auxiliary equipment and save the equipment occupied space. The temperature control device of this patent adopts a nested water channel design for the material tank. The small water temperature control system occupies a small area and can reduce the space of the hot air heating and large mold temperature control machine heating devices used in the prior art. This patent integrates the vacuum generator on the material tanks of A material and B material respectively, which can reduce the space and the investment in vacuum pumping auxiliary equipment.

[0078] (3) The processing equipment and processing technology provided by the present invention are very environmentally friendly:

[0079] The spraying equipment in the prior art widely has defects such as large pollution, high energy consumption, many processes, and low efficiency. The present invention adopts an in-mold one-step painting and forming process, which does not require multiple workstations and does not require paint, and perfectly matches the reaction molding paint. Compared with the prior art, the equipment process of the present invention has advantages such as being more environmentally friendly, lower energy consumption, fewer processes, and higher efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] The drawings are used to provide a further understanding of the present invention and constitute a part of the specification. They are used together with the embodiments of the present invention to explain the present invention and do not constitute a limitation to the present invention.

[0081] Figure 1 is a schematic diagram of an environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 1 ;

[0082] Figure 2 is a schematic diagram of an environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 2 ;

[0083] Figure 3 is a schematic diagram of an environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 3 ;

[0084] Figure 4 Schematic diagram of the environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 4 ;

[0085] Figure 5 Schematic diagram of the mixing head according to an embodiment of the present invention;

[0086] Figure 6 Schematic diagram of the connection between the material tank and the vacuum generator according to an embodiment of the present invention;

[0087] Figure 7 Photo of the first type of defective phenomenon;

[0088] Figure 8 Photo of the second type of defective phenomenon;

[0089] Figure 9 Photo of the third type of defective phenomenon;

[0090] Figure 10 Photo of the fourth type of defective phenomenon;

[0091] Figure 11 Overview of the I / O signal block diagram of the turntable mode according to an embodiment of the present invention;

[0092] Figure 12 Overview of the I / O signal block diagram of the sliding table mode according to an embodiment of the present invention;

[0093] Figure 13 Logic diagram of the system for processing unqualified products according to an embodiment of the present invention;

[0094] Figure 14 Schematic diagram of the environmentally friendly in-mold coating processing technology for plastic products according to an embodiment of the present invention;

[0095] Figure 15 Schematic diagram of the mold texture according to an embodiment of the present invention;

[0096] Figure 16 Schematic diagram of the environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 5 ;

[0097] Figure 17 Schematic diagram of the environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 6 ;

[0098] Figure 18 Schematic diagram of the environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 7 ;

[0099] Figure 19Schematic of the environmentally friendly in-mold coating processing equipment for plastic products according to an embodiment of the present invention Figure 8 ;

[0100] In the figure: 1. In-mold coating device; 101. A material tank; 1011. Discharge pipe A; 1012. Return pipe A; 102. B material tank; 1021. Discharge pipe B; 1022. Return pipe B; 103. Raw material stirrer; 104. Low-pressure feeding pump; 105. Heat preservation box; 106. Vacuum generator; 2. Color paste conveying device; 201. C material tank; 2011. Discharge pipe C; 2012. Return pipe C; 3. Mixing head; 301. Feeding port A; 302. Feeding port B; 303. Feeding port C; 304. Cleaning rod; 305. Control rod; 306. Hydraulic power station; 4. Molding die; 401. First half die; 402. Second half die; 403. Third half die; 404. Fourth half die; 5. Temperature control device; 501. Water-type raw material temperature control machine; 601. Bracket 1; 6011. AB material electric control cabinet; 6012. AB material automatic feeding equipment; 602. Bracket 2; 7. Injection molding device; 701. Automatic feeding equipment; 8. Automatic isolation guardrail; 801. Automatic part picking device; 802. Automatic trimming device; 9. Central control system. Detailed implementation manners

[0101] The present invention will be further described in detail below in conjunction with embodiments. The following embodiments are explanations of the present invention and the present invention is not limited to the following embodiments.

[0102] The embodiments according to the present invention will be described in detail below with reference to the accompanying drawings.

[0103] As Figures 1 to 19 shown, 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 A material and a B material tank 102 for supplying B material. The color paste conveying device 2 includes a C material tank 201 for supplying C material. The A material, the B material and the C material are mixed into a reaction molding coating inside the mixing head 3. The discharge end of the mixing head 3 is connected to the coating feeding end of the molding die 4;

[0104] In specific use, the preferred reaction molding coating of this patent is polyurethane (Polyurethane, PUR). At this time, the A material is polyether polyol, the B material is isocyanate, and the C material is polyether polyol containing color paste / pigment. The reaction molding coating can also be polyurea (Polyurea, PUA) or other two-component or multi-component coatings in addition to polyurethane.

[0105] The A material tank 101 is connected to the feed port A301 of the mixing head 3 through the discharge pipe A1011 and the reflux pipe A1012;

[0106] The B material tank 102 is connected to the feed port B302 of the mixing head 3 through the discharge pipe B1021 and the reflux pipe B1022;

[0107] The C material tank 201 is connected to the feed port C303 of the mixing head 3 through the discharge pipe C2011 and the reflux pipe C2012;

[0108] During specific design, the discharge pipe A1011, the reflux pipe A1012, the discharge pipe B1021, the reflux pipe B1022, the discharge pipe C2011, and the reflux pipe C2012 can all be set as pipelines with heating functions.

[0109] 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 residual coating material in the mixing head 3 (mainly the residual coating material on the mixing chamber and the pipe wall of the discharge pipe of the mixing head 3) and 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 the injection molding operation). The control rod 305 is used to block or open the feed port A301, the feed port B302, and the feed port C303;

[0110] When the control rod 305 is in the closed position: The A material can circulate in the A material tank 101, the discharge pipe A1011, and the reflux pipe A1012. The B material can circulate in the B material tank 102, the discharge pipe B1021, and the reflux pipe B1022. The C material can circulate in the C material tank 201, the discharge pipe C2011, and the reflux pipe C2012.

[0111] As Figure 1 、 2 As shown in 4 and 5, the main functions of the mixing head 3 are that the A material and the B material, through the control system of the in-mold coating device 1, respectively reach the high-pressure metering pump from the corresponding material tanks through the feeding pumps, and enter the mixing head 3 together with the C material flowing out from the color paste tank (C material tank 201) through the specific pipelines with heating according to the preset flow rate, ratio, and pressure (such as 150 bar). The A material, the B material, and the C material are intensively mixed in the mixing head 3 in a turbulent flow manner. After mixing, they enter the mold from the runner and form a colored coating layer on the surface of the substrate in the mold.

[0112] The main function of the cleaning rod 304 is to clean the PUR residual material in the mixing chamber of the in-mold mixing head and the pipe wall of the discharge pipe.

[0113] The control rod 305 is hydraulically controlled to precess. The function of the control rod 305 is to circulate the raw materials through the return chute of the control rod 305. More specifically, a self-sealing groove may be provided on the control rod 305. When the mixing head 3 mixes, the raw materials are injected into the self-sealing groove on the control rod 305 to react and foam, so as to seal the gap between the control rod 305 in the mixing head 3 and the inner wall of the mixing head, preventing the raw materials from leaking.

[0114] In specific design, by setting a return chute (keyway) on the surface of the control rod 305, it is convenient for material A, material B, and material C to flow back from the discharge pipe to the return pipe and the material tank. The circulating flow of the raw materials can ensure the timely reaction and operation of the equipment, prevent liquid accumulation, and ensure the stable operation of the equipment. At this time, the raw materials of the mixing head 3 enter the spray nozzle of the spray barrel through the feed hole of the mixing head 3 and then enter the return chute of the control rod 305.

[0115] In a specific embodiment of the present invention, the A material tank 101, the B material tank 102, and the C material tank 201 are all connected with a temperature control device 5. The temperature control device 5 includes a water-type raw material temperature control machine 501. The water-type raw material temperature control machine 501 is communicated with a jacketed heat exchanger arranged outside the A material tank 101 and the B material tank 102 through a water delivery pipeline, and a heat insulation and heat preservation layer is arranged outside the jacketed heat exchanger.

[0116] By controlling the water temperature in the jacketed heat exchanger, the temperatures of material A and material B can be indirectly controlled. In specific production, a water storage tank and an electric heater are installed inside the water-type raw material temperature control machine 501. The control accuracy of the water-type raw material temperature control machine 501 is ±1°C. The water-type raw material temperature control machine 501 is respectively installed near the A material tank 101, the B material tank 102, and the C material tank 201. The water-type raw material temperature control machine 501 continuously supplies circulating hot water to the jacketed heat exchangers of the A material tank 101, the B material tank 102, and the C material tank 201. The efficient circulating water temperature control system can ensure that the temperature control of the material tank is accurately controlled to reach ±1°C.

[0117] In a specific embodiment of the present invention, the A material tank 101 and the B material tank 102 are both connected with a raw material stirrer 103, and the raw material stirrer 103 can stir continuously or indirectly. Through stirring, the uniformity and temperature stability of materials A and B can be maintained.

[0118] In a specific embodiment of the present invention, the A material tank 101 and the B material tank 102 are both connected with a low-pressure feeding pump 104, and the two low-pressure feeding pumps 104 are respectively connected to different high-pressure metering pumps through pipelines. In specific design, the low-pressure feeding pump 104 can be arranged below the A material tank 101 and the B material tank 102, and is used to pump the raw materials out of the material tank and convey them to the side of the high-pressure metering pump.

[0119] In a specific embodiment of the present invention, the high-pressure metering pump is arranged in the heat preservation box body 105, and a volumetric flowmeter is also arranged in the heat preservation box body 105. The volumetric flowmeter is connected to the high-pressure metering pump through a pipeline. The volumetric flowmeter can be used to measure the conveying rate of the high-pressure metering pump.

[0120] In a specific embodiment of the present invention, a vacuum generator 106 is connected to both the A material tank 101 and the B material tank 102.

[0121] During specific design, the vacuum generator 106 can be respectively arranged on the A material tank 101 and the B material tank 102 to continuously extract air from the material tanks, so as to ensure that the vacuum degree in the raw material tanks can be less than 0.2 bar (i.e., the air pressure can be less than 0.8 bar), and ensure that the air in the raw materials is discharged as much as possible. As Figure 6 shown, by installing the vacuum generator 106 on the A material tank 101 and the B material tank 102 respectively, the following beneficial effects can be obtained: ① It can solve the problems of bubbles and poor appearance existing in the polyurethane (PUR) layer on the product surface; ② When new materials are added to the A material tank 101 and the B material tank 102, the bubbles generated in the material tanks can be effectively extracted in time, thereby ensuring the product quality; ③ By integrating the vacuum generator 106 on the A material tank 101 and the B material tank 102 respectively, the investment in plant space and auxiliary equipment can be effectively reduced.

[0122] In a specific embodiment of the present invention, the mixing head 3 is connected to the hydraulic power station 306, and the cleaning rod 304 and the control rod 305 are telescoped and advanced by the 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.

[0123] In a specific embodiment of the present invention, the A material tank 101, the B material tank 102, and the hydraulic power station 306 are all installed on the first bracket 601, and an AB material electric control cabinet 6011 and an AB material automatic feeding device 6012 are also arranged on the first bracket 601.

[0124] The AB material electric control cabinet 6011 is used to control the main process parameters such as the flow rate, temperature, ratio, opening time of the mixing head, and injection speed of the A and B raw materials in the equipment. As Figure 3 shown, the heat preservation box body 105 is arranged on the second bracket 602. The integration of the equipment on the first bracket 601 can greatly compress the site space required by the equipment. By independently arranging the heat preservation box body 105 on the second bracket 602, the interference of the vibration of the equipment on the first bracket 601 to the high-pressure metering pump and the volumetric flowmeter in the heat preservation box body 105 can be reduced, thereby effectively ensuring the processing accuracy.

[0125] In a specific embodiment of the present invention, the color paste conveying device 2 is arranged on the color paste station bracket.

[0126] The color paste conveying device 2 specifically includes a C material tank 201, a water-based raw material temperature control machine connected to the C material tank, a pumping piston pump, a volumetric flow meter, and a C material electric control cabinet. The present invention also includes a centralized control system 9, which is used to control each group of device equipment in the present invention (including the AB material electric control cabinet and the C material electric control cabinet).

[0127] During specific use, according to the physical property requirements of the customer's materials, the C material is set according to the mixing ratio of 1% to 8% of the total volume of the A material, B material, and C material. The C material flows out from the C material tank 201 through a pumping piston pump (the pumping piston pump can make the maximum pressure of the C material reach 220 bar, which belongs to a high-pressure pump) at a preset flow rate, pressure (such as 150 bar), and ratio from the discharge pipe C2011 with a heating function; the A material and the B material respectively flow from the corresponding material tanks, pass through the low-pressure feeding pump 104 to reach the high-pressure metering pump, and flow out from the discharge pipes A1011 and B1021 with heating functions at a preset flow rate, pressure (such as 150 bar), and ratio; the A material, B material, and C material are intensively mixed in a turbulent manner in the mixing head 3, and after the mixing is completed, the reaction-molded coating enters the forming mold 4 from the pipeline and forms a colored PUR polyurethane / PUA polyurea coating layer on the surface of the substrate in the forming mold 4.

[0128] In a specific embodiment of the present invention, the environmentally friendly in-mold coating processing equipment for plastic products further includes an injection molding device 7, and the injection molding device 7 is provided with a plastic automatic feeding device 701, a hopper, and a raw material drying system.

[0129] In a specific embodiment of the present invention, the forming mold 4 includes a sliding table template and a fixed template;

[0130] Two half molds, namely half mold one and half mold two, are provided on the sliding table template, and half mold three is provided on the fixed template. The half mold one and the half mold two can be switched to dock with the half mold three by translational sliding;

[0131] The half mold three is connected to the discharge end of the injection molding device 7 and the discharge end of the mixing head 3;

[0132] After the half mold one and the half mold three are clamped, an injection molding substrate cavity is formed;

[0133] After the half mold two and the half mold three are clamped, a reaction-molded coating cavity is formed.

[0134] In a specific embodiment of the present invention, the forming mold 4 includes a moving template and a front template;

[0135] Such as Figure 14As shown, the moving template is provided with a rotating mechanism that rotates 360° around 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;

[0136] The front template is provided with a horizontal moving mechanism. The front template includes a third half mold 403 and a fourth half mold 404;

[0137] The third half mold 403 is connected to the discharging end of the injection molding device 7. The first half mold 401 and the second half mold 402 can both form an injection molding base material cavity after being clamped with the third half mold 403;

[0138] The fourth half mold 404 is connected to the discharging end of the mixing head 3. The first half mold 401 and the second half mold 402 can both form a reaction molding coating cavity after being clamped with the fourth half mold 404.

[0139] Taking PUR polyurethane coating and plastic base material as an example, in specific design, ejector pins and exhaust mechanisms are arranged on the first half mold 401 and the second half mold 402 of the moving template, and a PUR polyurethane feeding runner is arranged on the fourth half mold 404 of the fixed mold. Preferably, the temperature control unit 1 controls the first half mold 401 and the second half mold 402 of the moving template and the third half mold 403 of the front template. According to different specifications and types of raw materials, the mold temperatures of the first half mold 401, the second half mold 402, and the third half mold 403 are 80°C to 110°C. Preferably, the mold temperature control unit 2 controls the fourth half mold 404 of the front template, and the mold temperature of the fourth half mold 404 is 90°C to 130°C. Controlling the mold temperatures of the moving template and the front template can further reduce the adverse effects of the mold temperature on PUR polyurethane and base material. Setting the mold temperatures of the first half mold 401 and the second half mold 402 of the moving template and the third half mold 403 of the front template in the range of 80°C to 110°C and the mold temperature of the fourth half mold 404 of the front template in the range of 90°C to 130°C can enable the PUR material to react and cure steadily after entering the cavity without affecting the product quality and subsequent processes. When the mold temperature of the fourth half mold 404 is lower than 90°C and the mold temperatures of the first half mold 401, the second half mold 402, and the third half mold 403 of the front template are lower than 80°C, there will be Figure 7 、 8 such poor curing and insufficient reaction of the PU layer as shown. When the mold temperature of the fourth half mold 404 is higher than 130°C and the mold temperatures of the first half mold 401, the second half mold 402, and the third half mold 403 of the front template are higher than 110°C, there will be Figure 9 、 10 such adverse phenomena as difficult glue injection resulting in material shortage and overall deformation of the product as shown.

[0140] In specific use, taking PUR polyurethane coatings and plastic substrates as examples, after the two half-molds of the moving template and the two half-molds of the front template are closed, an injection-molded substrate cavity and a reaction-injection molded coating cavity (PUR polyurethane cavity) are respectively formed. After the forming mold 4 is closed, injection starts in the injection-molded substrate cavity formed by the first half-mold 401 of the moving template and the third half-mold 403 of the front template. When the substrate is completed with injection, pressure holding, filling, and cooling, the mold is opened. The moving template rotates 180° to send the first half-mold with the injected substrate to the fourth half-mold 404. The forming mold 4 is closed again. Injection of plastic starts in the injection-molded substrate cavity formed by the second half-mold 402 of the moving template and the third half-mold 403 of the front template. And in the reaction-injection molded coating cavity (PUR polyurethane cavity) formed by the first half-mold 401 and the fourth half-mold 404 of the front template, a reaction injection molding (RIM) device starts to inject and pour the reaction-injection molded coating (PUR polyurethane). At this time, the injection-molded substrate in the reaction-injection molded coating cavity (PUR polyurethane cavity) can form an in-mold painting coated product with high surface quality, without placing the injection-molded substrate product into another set of equipment for surface spraying or painting processing. Through the present invention, the painting process can be realized in the mold, thereby effectively improving production efficiency.

[0141] In a specific embodiment of the present invention, an automatic workpiece taking device 801 for taking out workpieces from the forming mold 4 is provided on one side of the forming mold 4. An automatic trimming device 802 for trimming workpieces is provided on one side of the automatic workpiece taking device 801. Both the automatic workpiece taking device 801 and the automatic trimming device 802 are arranged in the automatic isolation guardrail 8.

[0142] In a specific embodiment of the present invention, the number of the C material tanks 201 is two or more.

[0143] Setting the number of the C material tanks 201 to two or more takes into account color switching. The present invention can quickly complete multiple color switches within 5 minutes. As Figure 4 shown, the A and B components in the A material tank 101 and the B material tank 102 are kept clean. Color pastes are added to the color paste conveying device 2. Different color C material tanks 201 are switched through the replacement unit of the color paste conveying device 2, and different color switches can be completed in about 5 minutes.

[0144] In a specific embodiment of the present invention, the environmentally friendly in-mold coating processing equipment for plastic products is controlled by the input and output logic of digital signals. The control logic of the digital signals includes one or more of the following:

[0145] D1. When a failure occurs in the environmentally friendly in-mold coating processing equipment for plastic products, an "DO mechanical failure" signal is output;

[0146] D2. When the first half - mold and the third half - mold are clamped to form an injection - molded substrate cavity, output the signal "DO cleaning rod advances", and keep outputting until it is disconnected before the signal "DO ready for foaming" is output; after the cleaning rod 304 advances in place, the system outputs the signal "DI cleaning rod advances in place", and the "DI cleaning rod advances in place" signal is active at high level;

[0147] 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 when injecting the plastic substrate. In the turntable mode (the molding die 4 includes a moving template and a front template), there is no need to output the signal "DO cleaning rod advances", while in the sliding - table mode (the molding die 4 includes a sliding - table template and a fixed template), when the first half - mold and the third half - mold are clamped to form an injection - molded substrate cavity, it is necessary to output the "DO cleaning rod advance signal", and keep outputting until it is disconnected before the "DO ready for foaming" signal is output. This is because of the different mold structures. In the turntable - mode mold, the injection of the substrate and the injection of polyurethane are respectively connected to different half - molds (the third half - mold 403 is connected to the discharge end of the injection device 7, and the fourth half - mold 404 is connected to the discharge end of the in - mold coating device 2), so there is no need to consider the problem of the substrate entering the injection gun head of the polyurethane equipment. However, the sliding - table mode is different. In the sliding - table mode, the injection of the substrate and the injection of polyurethane share a cavity surface (the third half - mold is connected to the discharge end of the injection device 7 and the discharge end of the in - mold coating device 2), so when clamping the mold to inject the substrate, it is necessary to prevent the plastic substrate from entering the injection gun head of the polyurethane equipment. Therefore, the cleaning rod 304 should be kept in the advanced position and last until the polyurethane injection preparation signal is output. In the turntable mode, the "DO cleaning rod advances" signal skips the control process and directly enters the next program.

[0148] Active at high level means that if the signal is a high - charge to activate the alarm, 0 represents low level, 1 represents high level, 0 - 14V is low level, and 15 - 28V is high level. In the sliding - table mode, before the injection molding machine (IMM) injects, it checks the signal "DI cleaning rod advances in place". If the "DI cleaning rod advances in place" signal is lost, the plastic injection action is prohibited, and an alarm "cleaning rod is not in the advanced position" is prompted. At this time, there is no need to jump out of the automatic mode. Just wait in place. After the "DI cleaning rod advances in place" signal is input into the system, the plastic injection can continue. Monitoring the position of the cleaning rod 304 in the sliding - table mode is for the consideration of quality, safety, and equipment stability. Because in the sliding - table mode, the injection of the substrate and the injection of polyurethane share a cavity surface (the third half - mold) on the fixed - template (also called the stationary mold) side, so when injecting the substrate, it is necessary to ensure that the cleaning rod 304 is in the advanced position to prevent the substrate from being injected into the gun head of the polyurethane equipment.

[0149] D3. When the environmentally friendly plastic product in - mold coating processing equipment is in semi - automatic / full - automatic mode, output the signal "DO automatic operation";

[0150] The differences between the semi-automatic and fully-automatic environmental protection plastic product in-mold coating processing equipment lie in that after a complete cycle in the semi-automatic mode, it is necessary for manual confirmation and pressing the start button to execute the next cycle, while in the fully-automatic mode, the next cycle can be automatically executed without manual confirmation after a complete cycle.

[0151] D4. When the reaction injection molding coating cavity is formed after mold closing, trigger the "DO ready to foam" signal and disconnect the "DO ready to foam" signal before the output of the "DO start to foam" signal;

[0152] During specific design, the output delay time of the "DO ready to foam" signal can be set. The task executed between the "DO ready to foam" signal and the "DO start to foam" signal is to build high pressure for polyurethane, that is, to build high pressure for polyurethane material A and material B (entering the high-pressure metering pump) to prepare for injection into the molding cavity.

[0153] D5. When the system receives the "DI ready to foam" signal, output the "DO start to foam" signal; when the system receives the "DI foam completed" signal, disconnect the output of the "DO start to foam" signal and enter the foam cooling timing. The "DI foam completed" signal is valid at high level; the "DI ready to foam" signal is valid at high level, and the output of the "DO start to foam" signal is prohibited without the high-level signal; the "DI foam completed" signal is valid at high level; the purpose of the foam cooling timing is to accurately measure the polyurethane curing and cooling time to ensure product quality. When the conveying speeds of polyurethane material A and material B in the polyurethane equipment reach the set injection speed and there is no fluctuation during operation at this speed for more than 2 s, the system will judge that the polyurethane injection condition is met and output the "DI ready to foam" signal.

[0154] D6. When the foaming machine is foaming, the system outputs the "DI foaming" signal, and the "DI foaming" signal is valid at high level with no alarm output;

[0155] D7. Trigger the "DO blow cleaning rod" signal through the "DI foam completed" signal;

[0156] During the specific design, the "DO blow cleaning rod" signal can set the delay time and output time. After the "DO blow clean the cleaning rod" signal is sent, a blowing valve will act at the gun head of the polyurethane foaming equipment, aiming to remove the residual polyurethane material around the cleaning rod 304 and prevent defects during the next cycle injection. More specifically, the system does not require the "DO cleaning rod retraction" signal. When polyurethane is injected and foamed, the cleaning rod 304 will automatically perform a retraction action, and when the foaming is completed, the cleaning rod 304 will automatically perform a forward action. This program can be set through the built-in settings of the polyurethane equipment. Setting the delay time is to more precisely control the reasonable blowing timing, and the output time is to precisely control the blowing time.

[0157] D8. When a failure occurs in the foaming machine, the system outputs the "DI foaming machine failure" signal. The "DI foaming machine failure" signal is active high. When the "DI foaming machine failure" signal is input to the system, the system alarms "foaming machine failure", and the system prohibits entering the automatic mode with "foaming action". If in the automatic mode, it will jump to the manual mode after the cycle ends;

[0158] 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 mode and the full-automatic mode proposed above. The manual mode is the third mode of the environmentally friendly plastic product in-mold coating processing equipment. In this mode, the system does not send control signals to the polyurethane equipment.

[0159] D9. When the downstream equipment of the injection molding machine detects unqualified products, it inputs the "DI product unqualified" signal to the system. The "DI product unqualified" signal is active high.

[0160] When the system receives the "DI product unqualified" signal, the IMM injection molding machine system outputs the "DI product unqualified" signal (waste product signal) to the automation equipment (including the automatic picking device 801, the automatic trimming device 802, etc.). In specific use, the control software of the polyurethane reaction molding equipment can accurately measure whether the weight, time, and speed of the injected polyurethane meet the set requirements. If the measured actual weight, time, or speed of the injected polyurethane deviates from the actual set value by more than 1%, the polyurethane reaction molding equipment will output a high-level product unqualified signal to the IMM injection molding machine system, and the IMM injection molding machine system will automatically output the product unqualified signal to the automation equipment after receiving this signal. Figure 13 It shows the logic diagram of the system's handling of unqualified products in the present invention.

[0161] Preferably, Figure 11 、 12 It is an overview of the I / O signal block diagram in the rotary table mold and the sliding table mode.

[0162] The above control logic can flexibly match different types of injection molding equipment and mold - turning equipment according to the production requirements of customers to meet the production of products with different specifications. The "system" mentioned in the above control logic can be integrated in, for example, Figure 2 the centralized control system 9 shown in

[0163] An environmentally friendly in - mold coating processing technology for plastic products uses environmentally friendly in - mold coating processing equipment, as shown in Figure 14 and includes the following steps:

[0164] S01. Clamp the mold. At this time, the first half - mold 401 and the third half - mold 403 are clamped to form an injection - molding substrate cavity for the first workpiece, and the injection device 7 injects the first workpiece substrate into the injection - molding substrate cavity.

[0165] S02. Keep the mold clamped and perform pressure holding and cooling and shaping of the first workpiece substrate.

[0166] S03. Open the mold. The first workpiece substrate adheres to the first half - mold 401. After the moving template rotates 180°, the mold is clamped again. At this time, the first half - mold 401 and the fourth half - mold 404 are clamped to form a reaction - forming coating cavity with the first workpiece substrate inside, and the second half - mold 402 and the third half - mold 403 are clamped to form an injection - molding substrate cavity for the second workpiece.

[0167] S04. Keep the mold clamped. While the mixing head 3 injects the reaction - forming coating onto the surface of the first workpiece substrate, the injection device 7 synchronously injects the second workpiece substrate.

[0168] S05. Keep the mold clamped. While the reaction - forming coating reacts and forms on the surface of the first workpiece substrate, the pressure holding and cooling and shaping of the second workpiece substrate are carried out synchronously.

[0169] S06. Open the mold. The first workpiece with coating adheres to the first half - mold 401, the second workpiece substrate adheres to the second half - mold 402, and the automatic workpiece - taking device 801 takes out the first workpiece with coating from the first half - mold 401.

[0170] S07. After the moving template rotates 180°, the mold is clamped again. At this time, the second half - mold 402 and the fourth half - mold 404 are clamped to form a reaction - forming coating cavity with the second workpiece substrate inside, and the first half - mold 401 and the third half - mold 403 are clamped to form an injection - molding substrate cavity for the third workpiece.

[0171] S08. Keep the mold clamped. While the mixing head 3 injects the reaction - forming coating onto the surface of the second workpiece substrate, the injection device 7 synchronously injects the third workpiece substrate.

[0172] S09. Keep the mold closed. While the reactive molding coating is being formed on the surface of the second workpiece substrate, the pressure holding and cooling and shaping of the third workpiece substrate are carried out synchronously.

[0173] S010. Open the mold. The second workpiece with the coating adheres to the second half-mold 402, the third workpiece substrate adheres to the first half-mold 401, and the automatic workpiece picking device 801 takes out the second workpiece with the coating from the second half-mold 402.

[0174] Repeating steps S07 - S010 can achieve continuous and efficient production of environmentally friendly in-mold coating for plastic products.

[0175] S01 - S010 are the processes for one-step in-mold coating after the injection molding machine forms the substrate once. In this process, the substrate does not need to be demolded first and then transported to the painting station through a transfer method for painting. It can solve the problems of product deformation and difficult secondary positioning at the painting station. Specifically, in implementation, it can be summarized as follows: The molding die 4 closes. First, a thermoplastic substrate is injected. After pressure holding, filling, and cooling are completed, the molding die 4 opens and rotates 180° in the direction of the operating side through a turntable to move the injection-molded substrate to another cavity corresponding to the casting of PUR polyurethane. The molding die 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 onto the surface of the substrate (simultaneously, the injection molding machine injects the substrate for the next cycle). After the coating equipment finishes casting, the workpiece in the mold is cured by reaction, and then the molding die 4 opens and ejects the workpiece, and the automatic workpiece picking device 801 (mechanical gripper) takes out the workpiece.

[0176] In a specific embodiment of the present invention, the injection molding substrate material of the injection molding device includes one or more of polypropylene, PC, ABS, PC + ABS, PA66, and carbon fiber.

[0177] In a specific embodiment of the present invention, when the reactive molding coating is polyurethane and the molding die 4 includes the moving template and the front template, the melting temperature of the barrel of the injection molding device 7 is 200°C - 320°C, the mold temperature of the first half-mold 401, the second half-mold 402, and the third half-mold 403 is 80°C - 110°C, the mold temperature of the fourth half-mold 404 is 90°C - 130°C, the temperature of the polyurethane material entering the reactive molding coating cavity is 60°C - 90°C, the working pressure of the polyurethane material entering the reactive molding coating cavity is 11 MPa - 21 MPa, and the curing time of the polyurethane material in the reactive molding coating cavity is 20 s - 200 s.

[0178] In a specific embodiment of the present invention, the injection-molded substrate material is polypropylene, the melting temperature of the barrel of the injection molding device 7 is 170°C to 250°C, the injection-molded substrate is a polypropylene substrate, and the in-mold coating process of the polypropylene substrate includes the following steps:

[0179] S11. The injection molding device 7 injects a polypropylene substrate into the injection-molded substrate cavity;

[0180] S12. The polypropylene substrate after injection molding is sent to a PLASMA surface treatment device of model SPA2800 by a turntable rotation for plasma treatment;

[0181] S13. Inject polyurethane material into the mold on the surface of the polypropylene substrate after plasma treatment;

[0182] S14. Open the mold to take out the finished product with polypropylene and polyurethane materials bonded together.

[0183] In a specific embodiment of the present invention, the technical parameters of the PLASMA surface treatment device are: voltage 190V - 250V, frequency 40HZ - 60HZ, current 0.25A - 0.35A, air pressure 0.4bar - 0.8bar, treatment width 20 - 90mm. Preferably, the voltage is 220V, the frequency is 50HZ, the current is 0.31A, the air pressure is 0.6bar, and the treatment width is 75mm.

[0184] In a specific embodiment of the present invention, the technical parameters of the PLASMA surface treatment device are that 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°C - 100°C. 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°C.

[0185] In a specific embodiment of the present invention, the environmentally friendly in-mold coating processing equipment in the present invention can select various types of mold microstructures for production according to customer production requirements, such as: flower broken patterns, mirror surfaces, genuine leather, sandblasted textures, diamond cut surfaces, engraved patterns, etc. fine textures. During specific implementation, polyurethane, as a "smart" material, has characteristics such as being soft or hard, wear-resistant, scratch-resistant, self-healing, etc., and the color can be freely matched, with the characteristic of bright color. The unique perfect replication and other advantages of polyurethane materials enable the mold surface texture to be replicated almost 99% completely. To better present the effect and meet the actual functional requirements, the mold texture can be made on the substrate surface or on the PUR polyurethane surface layer. The specific texture effects include Figure 15 the following effects shown in

[0186] A. Genuine leather effect: The texture of the genuine leather effect can be applied to the surface of the substrate or on the PUR polyurethane surface layer to achieve a perfect replication effect;

[0187] B. LOGO effect: The texture of the LOGO effect can be applied to the surface of the substrate or on the PUR polyurethane surface layer to achieve a perfect replication effect;

[0188] C. Smart film effect: The smart film can be embedded using IMD, IML, and IMR processes to achieve a smart surface effect;

[0189] D. Multiple types of texture effects: The woven texture, diagonal texture, wave texture, and Figure 15 other effect textures shown in D can be applied to the surface of the substrate or on the PUR polyurethane surface layer to achieve a perfect replication effect.

[0190] E. Diamond cut surface effect: The diamond cut surface effect and Figure 15 other effect textures shown in E can be applied to the surface of the substrate or on the PUR polyurethane surface layer to achieve a perfect replication effect.

[0191] F. Wood grain texture effect: The texture effect of wood and Figure 15 other effect textures shown in F can be embedded using IMD, IML, and IMR processes to achieve a high - level sensory effect of wood grain; The texture in the wood grain texture effect adheres to the surface of the substrate, and the texture surface layer is the PUR polyurethane surface layer.

[0192] In a specific embodiment of the present invention, the environmentally friendly in - mold coating processing equipment for plastic products in the present invention can be flexibly paired with the following different types of injection molding machines according to the production requirements of customers:

[0193] As Figure 16 shown, the environmentally friendly in - mold coating processing equipment for plastic products can be paired with an electric injection molding machine with a clamping force of 50 tons to 450 tons or even a larger tonnage, so as to meet the in - mold coating process requirements for precision small - gram - weight products of 30 g to 450 g.

[0194] As Figure 17 shown, the environmentally friendly in - mold coating processing equipment for plastic products can be paired with a hydraulic injection molding machine with a clamping force of 450 tons to 5500 tons or even a larger clamping force tonnage, to meet the in - mold coating process requirements for products of 500 g to 3000 g or even larger.

[0195] As Figure 18 shown, the environmentally friendly in - mold coating processing equipment for plastic products can be paired with a shuttle or multi - shot multi - component injection molding machine with a clamping force of 450 tons to 5500 tons or even a larger clamping force tonnage, to meet the in - mold coating process requirements for products of 500 g to 4000 g or even larger.

[0196] As Figure 19 shown, the environmentally friendly in-mold coating processing equipment for plastic products can be paired with a mold turning die carrier equipment with a clamping force ranging from 50 tons to 1300 tons or even greater, meeting the in-mold coating process requirements of products in different application scenarios.

[0197] In summary, the environmentally friendly in-mold coating processing equipment of the present invention has a high degree of equipment integration, can reduce processing procedures, is stable, flexible and convenient to operate, can obtain a high-quality product surface with various color effects, can be freely paired with different types of injection molding machines and mold turning die carrier equipment according to customer production needs, and can meet the customer production needs in different application scenarios.

[0198] It should be noted that the terms used in the present invention are only for describing specific embodiments and do not limit the scope of the present invention. As shown in the specification of the present invention, unless the context clearly indicates an exception, words such as "a", "an", "one" and / or "the" are not specifically singular and may also include the plural. The term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or elements inherent to such process, method or device. Without further limitation, an element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method or device including the element.

[0199] It should also be noted that the orientation or positional relationship indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Unless otherwise clearly specified and limited, the terms "installation", "connection", "connection", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0200] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the technical solutions of the embodiments of the present invention.

[0201] In addition, it should be noted that for the specific embodiments described in this specification, the shapes, names of the components, etc. can be different. Any equivalent or simple changes made according to the structure, features, and principles described in the inventive concept of the present invention are included in the protection scope of the present invention. Those skilled in the technical field to which the present invention pertains can make various modifications or supplements to the described specific embodiments, or use similar ways for substitution, as long as they do not deviate from the structure of the present invention or exceed the scope defined by the claims, they should fall within the protection scope of the present invention.

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 mold (4), characterized in that: The in-mold coating device (1) comprises an A material tank (101) for supplying A material, and a B material tank (102) for supplying B material. The color paste conveying device (2) comprises a C material tank (201) for supplying C material. The A material, the B material, and the C material are mixed inside the mixing head (3) to form a reactive molding coating. The discharge end of the mixing head (3) is connected to the coating feed end of the molding die (4). The A material tank (101) is connected to the feed port A (301) of the mixing head (3) via a discharge pipe A (1011) and a return pipe A (1012); The B material tank (102) is connected to the feed port B (302) of the mixing head (3) via a discharge pipe B (1021) and a return pipe B (1022). The C material tank (201) is connected to the feed port C (303) of the mixing head (3) via a discharge pipe C (2011) and a return pipe C (2012); The mixing head (3) is provided with a cleaning rod (304) and a control rod (305), wherein the cleaning rod (304) is used to clean paint residues in the mixing head (3) and to block the discharge port of the mixing head (3), and the control rod (305) is used to block or open the feed port A (301), the feed port B (302) and the feed port C (303); When the control rod (305) is in the closed position: the A material can circulate in the A material tank (101), the discharge pipe A (1011) and the return pipe A (1012); the B material can circulate in the B material tank (102), the discharge pipe B (1021) and the return pipe B (1022); and the C material can circulate in the C material tank (201), the discharge pipe C (2011) and the return pipe C (2012); Among them, the control rod is provided with a self-sealing groove and a return groove. When the mixing head is mixing, the raw materials are injected into the self-sealing groove on the control rod for reaction and foaming, so that the gap between the control rod in the mixing head and the inner wall of the mixing head is sealed to prevent the raw materials from leaking.

2. The environmentally friendly in-mold coating processing equipment for plastic products according to claim 1 is 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) comprising a water-type raw material temperature controller (501), the water-type raw material temperature controller (501) being connected to a jacketed heat exchanger arranged outside the A material tank (101) and the B material tank (102) via a water pipeline, and a heat insulation layer is arranged outside the jacketed heat exchanger.

3. The environmentally friendly in-mold coating processing equipment for plastic products according to claim 2 is characterized in that: The A material tank (101) and the B material tank (102) are both connected to a raw material stirrer (103), and the raw material stirrer (103) can stir continuously or indirectly.

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

5. The environmentally friendly in-mold coating processing equipment for plastic products according to claim 4 is characterized in that: The high-pressure metering pump is arranged in a heat-insulating box (105), and a volume flow meter is also arranged in the heat-insulating box (105), and the volume flow meter is connected to the high-pressure metering pump via a pipeline.

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

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

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

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

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

11. The environmentally friendly in-mold coating processing equipment for plastic products according to claim 10, characterized in that: The forming mold (4) comprises a slide mold plate and a fixed mold plate; The slide template is provided with two half-molds, half-mold 1 and half-mold 2, and the fixed template is provided with half-mold 3. The half-mold 1 and the half-mold 2 can be switched to dock with the half-mold 3 by translation and sliding; The third half 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 molded together to form an injection molding substrate cavity; The second half mold and the third half mold are molded together to form a reaction molding coating cavity.

12. The environmentally friendly in-mold coating processing equipment for plastic products according to claim 10, characterized in that: The forming mold (4) comprises a movable mold plate and a front mold plate; The movable platen is provided with a rotating mechanism capable of rotating 360° along a vertical axis, and the movable platen is also provided with a horizontal movement mechanism, and the movable platen comprises 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 comprises 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), and the first half mold (401) and the second half mold (402) can be molded together with the third half mold (403) to form an injection molding base material cavity; The fourth half mold (404) is connected to the discharge end of the mixing head (3), and the first half mold (401) and the second half mold (402) can be molded together with the fourth half mold (404) to form a reaction molding coating cavity.

13. The environmentally friendly in-mold coating processing equipment for plastic products according to claim 12, characterized in that: An automatic piece taking device (801) for taking a workpiece out of the forming mold (4) is provided on one side of the forming mold (4), and an automatic trimming device (802) for trimming the workpiece is provided on one side of the automatic piece taking device (801), and both the automatic piece taking device (801) and the automatic trimming device (802) are arranged in the automated isolation fence (8).

14. The environmentally friendly in-mold coating processing 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 more than two.

15. The environmentally friendly in-mold coating processing equipment for plastic products according to any one of claims 10 to 12, characterized in that: The environmentally friendly in-mold coating processing equipment for plastic products is controlled by the input and output logic of digital signals, and the control logic of the digital signals includes one or more of the following: D1. When the environmentally friendly plastic product in-mold coating processing equipment fails, the output "DO mechanical failure" signal; D3. When the environmentally friendly plastic product in-mold coating processing equipment is in semi-automatic / fully automatic mode, the output "DO automatic operation" signal; D4. When the reaction molding coating cavity is formed after mold closing, the "DO ready to foam" signal is triggered, and the "DO ready to foam" signal is disconnected before the "DO start foaming" signal is output; 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 timing, the "DI foaming completed" signal is valid at a high level; the "DI ready for foaming" signal is valid at a high level, and the "DO start foaming" signal output is prohibited if no high-level signal is received; the "DI foaming completed" signal is valid at a high level; D6. When the foaming machine is foaming, the system outputs a "DI is foaming" signal. The "DI is foaming" signal is valid at a high level, and no alarm is output; D7. Trigger the "DO cleaning rod blowing" signal through the "DI foaming completed" signal; D8. When the foaming machine fails, the system outputs a "DI foaming machine failure" signal. The "DI foaming machine failure" signal is valid at a high level. When the "DI foaming machine failure" signal is input into the system, the system alarms "foaming machine failure" and prohibits the system from entering the automatic mode with "foaming action". If in the automatic mode, it jumps to the manual mode after the cycle ends; D9. When the downstream equipment of the injection molding machine detects unqualified products, a "DI product unqualified" signal is input to the system, and the "DI product unqualified" signal is valid at a high level.

16. An environmentally friendly in-mold coating process for plastic products, using the environmentally friendly in-mold coating process equipment for plastic products as claimed in claim 13, characterized in that: The steps include: S01. Mold closing, at which time the first half mold (401) and the third half mold (403) are molded together to form an injection molding substrate cavity for the first workpiece, and the injection molding device (7) injects the first workpiece substrate into the injection molding substrate cavity; S02. Maintaining the mold, maintaining pressure and cooling the first workpiece substrate; S03. Open the mold, attach the first workpiece substrate to the first half mold (401), and close the mold after the movable mold plate rotates 180 degrees. At this time, the first half mold (401) and the fourth half mold (404) are closed to form a reaction molding coating cavity with the first workpiece substrate built in, and 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 maintaining the mold, the mixing head (3) injects the reaction molding coating onto the surface of the first workpiece substrate, while the injection molding device (7) simultaneously injects the second workpiece substrate; S05. While the mold is being closed, the reaction-molded coating is reacted and molded on the surface of the first workpiece substrate, while the pressure holding and cooling of the second workpiece substrate are performed simultaneously; S06. The mold is opened, the first workpiece that has been painted is attached to the first half mold (401), the second workpiece substrate is attached to the second half mold (402), and the automatic removal device (801) removes the first workpiece that has been painted from the first half mold (401); S07. After the movable mold plate is rotated 180 degrees, the mold is closed. At this time, the second mold half (402) and the fourth mold half (404) are closed to form a reaction molding coating cavity with a second workpiece substrate built in, and the first mold half (401) and the third mold half (403) are closed to form an injection molding substrate cavity for the third workpiece; S08. While maintaining the mold, the mixing head (3) injects the reaction molding coating onto the surface of the second workpiece substrate, while the injection molding device (7) simultaneously injects the third workpiece substrate; S09. While the mold is being closed, the reaction-molding coating is being reacted and molded on the surface of the second workpiece substrate, while the pressure holding and cooling of the third workpiece substrate are being performed simultaneously; S010. Open the mold, attach the painted second workpiece to the second half mold (402), attach the third workpiece substrate to the first half mold (401), and remove the painted second workpiece from the second half mold (402) using the automatic pick-up device (801).

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, and PA66.

18. 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 carbon fiber and at least one of polypropylene, PC, ABS, PC+ABS, and PA66.

19. 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 mold (4) includes the movable mold plate and the front mold plate, the melting temperature of the barrel of the injection molding device (7) is 200°C to 320°C, the mold temperatures of the first half mold (401), the second half mold (402) and the third half mold (403) are 80°C to 110°C, the mold temperature of the fourth half mold (404) is 90°C to 130°C, the temperature of the polyurethane material entering the reaction molding coating cavity is 60°C to 90°C, the working pressure of the polyurethane material entering the reaction molding coating cavity is 11MPa to 21MPa, and the curing time of the polyurethane material in the reaction molding coating cavity is 20s to 200s.

20. The environmentally friendly in-mold coating process for plastic products according to claim 19, characterized in that: The injection molding substrate material is polypropylene, the melting temperature of the barrel of the injection molding device (7) is 170° C. to 250° C., the injection molding substrate is a polypropylene substrate, and the in-mold coating process of the polypropylene substrate comprises the following steps: S11. The injection molding device (7) injects a polypropylene substrate into the injection molding substrate cavity; S12. The completed injection-molded polypropylene substrate is sent to the PLASMA surface treatment equipment model SPA2800 by rotating the turntable for plasma treatment; S13. Injection molding of polyurethane material on the surface of a plasma-treated polypropylene substrate; S14. Open the mold and take out the finished product with polypropylene and polyurethane materials bonded together.

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: voltage 190V~250V, frequency 40HZ~60HZ, current 0.25A~0.35A, air pressure 0.4bar~0.8bar, and treatment width 20~90mm.

22. The environmentally friendly in-mold coating process for plastic products according to claim 21, 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 8 mm to 15 mm, the plasma moving speed is 50 mm / s to 150 mm / s, and the plasma temperature is 70° C. to 100° C.

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