Double-color injection molding process grating and preparation process thereof

Abstract

The invention relates to the technical field of automobile part manufacturing, in particular to a double-color injection molding process grating and a preparation process thereof. The grating comprises a white sheet and a black sheet; the white sheet is made of a transparent material, the black sheet is made of a non-transparent material, and the white sheet is located on the front side of the black sheet; the white sheet is designed to be unequal in material thickness, the front side surface of the black sheet is provided with a brand logo mounting area and a front camera mounting area, cutting openings are formed in the positions, corresponding to the brand logo mounting area and the front camera mounting area, of the white sheet, and the brand logo mounting area and the front camera mounting area are exposed out of the cutting openings. Through the double-layer design of the white piece and the black piece, the Logo mounting hole and the camera exposed area are integrated, disassembly parts are reduced, the white piece is subjected to CNC cutting, multi-brand Logo rapid adaptation is achieved, the black piece is directly exposed, a support is omitted, the manufacturing cost is remarkably reduced, and finally the refinement and light weight of the grating are achieved, and the percent of pass is increased.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile parts manufacturing, in particular to a two-color injection molding process grid and a preparation process thereof. Background Art

[0002] The automotive industry's requirements for front grilles are no longer limited to traditional decorative and air intake and cooling functions. As the automotive industry continues to evolve, automakers and customers are increasingly demanding the aesthetics of vehicle exteriors, leading to an increasing diversity in front grille designs. Simultaneously, to meet wind resistance requirements and meet the demands of new energy vehicle front end designs, grilles using two-color injection molding and injection molding processes are gaining popularity. These processes utilize injection molding and compression molding of different colored materials to achieve complex shapes and integrated multifunctional designs, enhancing the vehicle's refined appearance and brand recognition. While maintaining a decorative effect, they also address essential functions such as air intake and heat dissipation.

[0003] Existing technology uses a two-color injection molding process to achieve a combination of different colors and shapes on the grille. Two plastic materials of different colors are injected sequentially through an injection molding machine. The shape and structure of the mold cavity are then used to fuse the two materials at a specific location, forming a grille with a specific appearance and function. However, existing technology still has the following problems in terms of cost control, process complexity, and compatibility with surrounding structures:

[0004] First, there are structural and assembly issues: ① The brand logo and camera need to be installed on separate brackets, which increases the number of disassembled parts, resulting in increased costs and easy loosening; ② The glue sealing at the parting line between the transparent layer (white film) and the black layer (black film) is insufficient, posing a risk of cutting hands.

[0005] Secondly, process defects: ① Large transparent parts will shrink due to uneven material thickness, sudden changes in material thickness and a point of glue feeding; ② Traditional injection molding cannot suppress the shrinkage of polycarbonate, resulting in dimensional fluctuations and affecting the gap between the grille and the body. Summary of the Invention

[0006] In response to the shortcomings of the existing technology, the purpose of the embodiments of the present invention is to provide a two-color injection-molded grille. Through the double-layer design of white and black sheets, the logo installation hole and the camera exposed area are integrated to reduce the need for disassembly. The white sheet is CNC cut to achieve rapid adaptation of multiple brand logos, and the black sheet directly exposes the camera to eliminate the need for a bracket, significantly reducing manufacturing costs and ultimately achieving refinement, lightweighting and improved pass rate of the grille.

[0007] In order to achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0008] A two-color injection-molded grille includes a white sheet and a black sheet; the white sheet is made of transparent material, the black sheet is made of opaque material, and the white sheet is located in front of the black sheet; the white sheet is designed with unequal material thickness, and the front surface of the black sheet has a brand logo installation area and a front camera installation area. Cutting openings are provided at the positions of the white sheet corresponding to the brand logo installation area and the front camera installation area, and the brand logo installation area and the front camera installation area are exposed from the cutting openings.

[0009] Optionally, a chamfer structure is provided at the parting line of the white piece.

[0010] Optionally, the white sheet and the black sheet are fastened by gantry clamps and screws.

[0011] The embodiment of the present invention further provides a process for preparing a two-color injection molding grid according to any one of claims 1 to 3, comprising the following steps:

[0012] Injecting transparent melt into a single glue inlet point of the first cavity to form a white sheet semi-finished product;

[0013] Close the injection molding machine nozzle and push the cavity to slightly move and compress the melt;

[0014] Apply holding pressure and cool;

[0015] Transfer the blank semi-finished product to the second cavity;

[0016] Injecting opaque melt onto the back of the white semi-finished product to form a black sheet;

[0017] The finished two-color grille is ejected.

[0018] Optionally, the movement speed of the compressed melt is uniform.

[0019] Optionally, the holding time of the holding pressure is dynamically adjusted according to the ambient temperature.

[0020] Optionally, also include:

[0021] Real-time monitoring of melt pressure in multiple areas of the cavity;

[0022] Dynamically adjust the compression speed according to the pressure difference between the edge area and the central area;

[0023] Real-time monitoring of the change rate of the melt dielectric constant;

[0024] When the dielectric constant decrease rate is lower than the set threshold, it switches to the pressure holding stage.

[0025] Optionally, when the pressure difference exceeds a first set threshold, the compression speed is reduced until the pressure difference falls below a second set threshold and then restored.

[0026] Optionally, during the holding stage, a compensation pressure higher than the standard holding pressure is applied to the center area of ​​the cavity, and a compensation pressure lower than the standard holding pressure is applied to the edge area.

[0027] Optionally, the compensation pressure in the central area is 1.1-1.2 times the standard holding pressure, and the compensation pressure in the edge area is 0.85-0.95 times the standard holding pressure.

[0028] One or more technical solutions provided in the embodiments of the present invention have at least the following technical effects or advantages:

[0029] 1. In this invention's two-color injection-molded grille, the white panel is made of a transparent material, with unequal thicknesses creating a three-dimensional shape, enhancing the grille's refinement and layering of light and shadow. The black panel is made of an opaque material, and its front surface integrates the brand logo and front camera mounting areas. Cutouts are provided in the white panel corresponding to the brand logo mounting area, allowing the logo to be directly mounted on the black panel surface. The front camera mounting area is left exposed on the black panel surface, eliminating the need for a separate bracket. This structure, through the stacking of white and black panels, integrates functional areas (logo, camera) with the light-transmitting area, reducing the number of disassembled components, lowering costs, and improving assembly reliability.

[0030] 2. The two-color injection molding process grille of the present invention meets the requirements of appearance refinement, assembly, PQ, strength, etc., and improves satisfaction. The product has been used in two new models, and the refinement of the front face appearance has been significantly improved. In order to ensure the integrity of the injection molding process and the problem of weld marks, the white sheet has fewer openings, and low-pressure injection molding is used first, followed by spraying and cutting to ensure the overall beauty and diversity of the product.

[0031] 3. By combining single-point glue injection with a compression process, the blank fill rate is improved and short shots are avoided. Through the coordinated control of compression and pressure holding, the shrinkage of prismatic features is controlled. The cooling shrinkage rate of key areas of the blank is controlled to improve dimensional stability.

[0032] Additional advantages of the present invention will be given in the description which follows, and in part will be obvious from the description which follows, or may be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] To more clearly illustrate the embodiments of this application or the technical solutions in the prior art, the following briefly introduces the drawings required for the embodiments or the description of the prior art. Obviously, the drawings described below are only some of the embodiments described in this application. For those skilled in the art, other drawings can be derived from these drawings without inventive effort. In addition, the sizes or spacings between components are exaggerated to show the positions of the components, and the schematic diagrams are for illustrative purposes only.

[0034] Figure 1 is a schematic diagram of a grille explosion provided by an embodiment of the present invention;

[0035] Figure 2 is a schematic diagram of the grille appearance provided by an embodiment of the present invention;

[0036] Figure 3 is a schematic cross-sectional view of a grid provided by an embodiment of the present invention;

[0037] Figure 4 This is a schematic diagram of brand logo installation provided by an embodiment of the present invention;

[0038] Figure 5 This is a schematic diagram of the installation of a front camera provided by an embodiment of the present invention;

[0039] Figure 6 is a cross-sectional schematic diagram of the connection structure between the front fender and the grille provided by an embodiment of the present invention;

[0040] Figure 7 Schematic diagram of the sealing surface provided by an embodiment of the present invention;

[0041] Figure 8 This is a schematic diagram of chamfering a white piece provided by an embodiment of the present invention;

[0042] Figure 9 Schematic diagram of the preparation process provided by an embodiment of the present invention;

[0043] Figure 10 is a schematic diagram of a preparation device provided in an embodiment of the present invention;

[0044] In the picture: 1. White film; 2. Black film; 3. Brand logo; 4. Front camera; 5. Sealing surface; DETAILED DESCRIPTION

[0045] It should be noted that the following detailed description is illustrative and is intended to further illustrate the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof.

[0046] Example 1

[0047] This embodiment proposes a two-color injection molding process grille, which uses a 3600T large-scale injection molding machine as well as two-color injection molding, CNC cutting, and injection molding processes on the radiator grille. The design of unequal thickness of PC white sheet 1 solves the problems of process diversification and cost reduction. At the same time, a shielding bracket is added at the air intake position to solve the problem of leaking body beams and internal structures, achieving a breakthrough in novel and exquisite appearance.

[0048] like Figure 1 、 Figure 2 、 Figure 3 As shown, the double-color injection molding process grid includes a white sheet 1 and a black sheet 2; the white sheet 1 is made of transparent material, and the black sheet 2 is made of opaque material. The white sheet 1 is located in front of the black sheet 2. The white sheet 1 is designed with unequal material thickness, that is, a structural design with different thicknesses in different areas. Figure 4 、 Figure 5 As shown, the front surface of the black sheet 2 has a brand logo 3 installation area and a front camera 4 installation area, and the white sheet 1 positions corresponding to the brand logo 3 installation area and the front camera 4 installation area are provided with cutting openings, and the brand logo 3 installation area and the front camera 4 installation area are exposed from the cutting opening positions.

[0049] White panel 1 is transparent, while black panel 2 is opaque. Positioned in front of black panel 2, the combination of materials and positioning creates a two-tone visual effect, meeting the aesthetic demands of automotive exteriors while also adapting to the use of new energy vehicle fronts on gasoline-powered vehicles. The varying thickness of white panel 1 creates a three-dimensional effect, addressing the need for refined grille design. The brand logo 3 and front camera 4 mounting areas on the front of black panel 2 are directly exposed through corresponding cutouts in white panel 1, eliminating the need for additional disassembly and reducing the number of disassembled parts. This addresses the need for a versatile and diverse grille. The structural coordination of white panel 1 and black panel 2 optimizes the reliability of the overall design, meeting the demands of automotive quality and refined production.

[0050] White sheet 1 is a transparent layer, i.e. one shot, with different thickness to reflect the three-dimensional structure, black sheet 2 is a black piece, with different thickness not exceeding 5mm, and paint can be sprayed onto white sheet 1 from the hollow back of black sheet 2 to increase the color effect of the shape. Figure 6 As shown, it is a cross-sectional diagram of the connection structure between the front guard and the grille, and the grille periphery white piece 1 and black piece 2 double-color injection molding sealing surface 5 (as shown Figure 7 shown).

[0051] like Figure 8 As shown, the upper sealing surface 5 of the white piece 1 and the black piece 2 of the grid is solved. Due to process problems, it is impossible to insert the sealing glue. The 0.2mm position of the parting line of the white piece 1 is chamfered by 0.5mm, which not only ensures the sealing of the white piece 1, but also takes into account the human-machine interaction to prevent the parting line from cutting hands.

[0052] The white plate 1 and black plate 2 are fastened together using gantry clamps and screws. The gantry clamps provide pre-positioning and initial locking, simplifying the assembly process; the screws enhance the connection strength and ensure the stability of the grille's mating. This synergistic effect eliminates the problem of loosening the grille due to vibration and improves assembly efficiency.

[0053] In summary, this embodiment uses unequal material thicknesses to achieve a three-dimensional effect on the grille's highlights. A 3600T two-color injection molding machine and injection molding process are directly employed. White sheet 1 is designed with transparent PC material, while black sheet 2 is designed with black PC+ABS material. By varying the material thickness on white sheet 1, a three-dimensional effect is achieved, making the entire grille more refined and beautiful. Differently shaped holes are then made on black sheet 2, through which white sheet 1 emerges. Back-spray painting allows for a color design of the grille's shape. Furthermore, to position different brand logos, the grille utilizes CNC cutting at the logo location on white sheet 1. White sheet 1 is cut open, and each brand logo is assembled, achieving market segmentation. At the front camera 4 location, black sheet 2 is directly exposed, reducing the cost of disassembling components and arranging mounting brackets.

[0054] Example 2

[0055] When using transparent PC material for a front grille (1100×495mm), the appearance requirements prevent the use of multiple glue injection points, resulting in filling defects and shrinkage of the prismatic features of the two-color grille. This embodiment provides a preparation process for the two-color injection molding process described in Example 1. Through the compression process, it solves the problems of flow balance control and post-shrinkage suppression for single-point glue injection of large transparent parts.

[0056] The preparation process includes the following steps: injecting a transparent melt into a single glue inlet point of the first cavity to form a white semi-finished product; closing the injection molding machine nozzle, pushing the cavity slightly to compress the melt; applying holding pressure and cooling; transferring the white semi-finished product to the second cavity; injecting an opaque melt into the back of the white semi-finished product to form a black sheet; and ejecting the two-color grille finished product.

[0057] A transparent melt is injected into the single injection point of the first cavity to form a white semi-finished product. This single injection point avoids weld lines caused by multiple injection points and ensures the appearance integrity of the white product. After closing the nozzle, the cavity is slightly moved to compress the melt, which can compensate for insufficient pressure at the end of the melt flow, eliminate bubbles, and compact the resin, improving the filling quality of the white product. Applying holding pressure and cooling can suppress the post-shrinkage of the transparent material and ensure the dimensional stability of the white product. The white semi-finished product is transferred to the second cavity, providing an accurate position for the black product molding and ensuring the precise docking of the two-color structure. An opaque melt is injected into the back of the white product to form a black product, so that the black product covers the non-transparent area and forms the desired two-color structure. Finally, the finished product is ejected, completing the entire manufacturing cycle. Through the synergistic effect of the injection molding process, problems such as transparent material filling defects and unstable structural dimensions are solved, and the product qualification rate is improved.

[0058] The compressed melt moves at a constant speed, ensuring uniform pressure transfer from the mold cavity to the melt, avoiding local pressure spikes or drops caused by speed variations. This uniform pressure ensures even filling of the mold cavity, minimizing defects such as bubbles and sink marks caused by uneven localized force. This, combined with the melt compression process, ensures the structural integrity of the blank semi-finished product and improves its molding quality.

[0059] Specific steps are as follows Figure 9 ( Figure 10 As shown in the equipment schematic diagram, it includes:

[0060] Step 1: Mold Closure and First Shot of Blank Sheet: Close the mold and inject transparent PC material (melt temperature 280-300°C) into the cavity through a single injection point, with the injection volume accounting for 95% of the cavity volume. This ensures a seamless grille appearance and avoids weld lines caused by multiple injection points.

[0061] Step 2: Mold compression: Keeping the injection molding machine nozzle closed, control the ejector lever to push the cavity slightly backward 1.1 mm, and compress the melt at a constant speed of 0.8 mm / s for 3 seconds. This compression compensates for the insufficient pressure at the end of the flow during single-point injection, eliminates bubbles, and compacts the resin.

[0062] Step 3: Hold pressure and cool: Apply 80 MPa holding pressure for 40-45 seconds (dynamically selected based on ambient temperature), while circulating water in the cooling channel at 15°C to reduce the temperature. This suppresses the PC material's shrinkage and ensures dimensional stability in the prismatic feature area.

[0063] Step 4: Mold opening and turntable rotation: The mold is opened, and the robot grips the white semi-finished product; the turntable rotates 180° to move the white piece to the second cavity, preparing for the black piece molding station of two-color injection molding.

[0064] Step 5: Second mold closing and second shot of the black film: Close the second cavity and inject black PC+ABS material (melt temperature 250-260°C) onto the back of the white film at an injection pressure of 70 MPa. This creates a two-color structure, with the black film covering the non-transparent area.

[0065] Step 6: Open the mold, eject the part, and take out the component: Open the mold, the ejector mechanism ejects the grille assembly, and the robot takes the part, completing the two-color grille manufacturing cycle.

[0066] This embodiment solves the problem that the ejector structure cannot be arranged on the surface of transparent materials. Due to the requirements of transparent PC materials and the appearance of the grille, it is impossible to arrange the glue feeding point. The mold uses the injection molding process to inject glue at one point to achieve the injection molding of 1100*495 white pieces. The injection molding process has an additional compression process compared to the ordinary injection molding process. The cavity and the core are slightly separated by a distance. The ejector bar makes the cavity move forward slowly for compression, and the pressure is maintained and cooled, so that the molding is done in one color. Figure 8 shown.

[0067] At the same time, the problem of surface shrinkage at the position of the prismatic features of the two-color grille was solved. From a structural perspective, the height difference between the prismatic features and the surface was controlled within 1mm. From a process perspective, during the injection molding process, the mold was slightly opened by 1.1mm for compression molding. The amount of glue fed into the first shot of transparent PC was controlled to reduce the degree of subsequent shrinkage. The holding pressure and time of the second shot of black glue were lengthened, and the cooling time was increased to 40-45s.

[0068] Example 3

[0069] When ambient temperature and humidity fluctuate, fixed compression parameters (1.1mm slight opening, 40-45s hold) can lead to insufficient filling in the center area and inaccurate timing of the hold transition during the production of ultra-large two-color grilles (1100×495mm), resulting in a decrease in product yield. This embodiment integrates pressure gradient sensing with dielectric freezing point monitoring to achieve dynamic and precise control of the compression-hold process, improving the yield rate of two-color grille production.

[0070] The holding pressure duration is dynamically adjusted based on the ambient temperature. When the ambient temperature is high, the material cools slowly, so extending the holding time appropriately ensures sufficient melt solidification. When the ambient temperature is low, the material cools quickly, so shortening the holding time appropriately allows for faster cooling. This dynamic adjustment adapts to varying environmental conditions, ensuring that the holding stage effectively suppresses material shrinkage and maintains the dimensional stability of the white flakes and subsequent black flakes. This, combined with the holding and cooling steps, improves product dimensional consistency.

[0071] The preparation process also includes: real-time monitoring of the melt pressure in multiple areas of the cavity; dynamically adjusting the compression speed based on the pressure difference between the edge area and the center area; real-time monitoring of the rate of change of the dielectric constant of the melt; and switching to the holding pressure stage when the rate of decrease of the dielectric constant is lower than the set threshold.

[0072] Real-time monitoring of melt pressure in multiple areas of the cavity allows for a timely understanding of the melt's distribution within the cavity. Dynamically adjusting the compression speed based on the pressure differential between the edge and center areas prioritizes filling areas with insufficient pressure, ensuring uniform melt filling. Real-time monitoring of the melt's dielectric constant change rate captures the melt's critical solidification point. When the dielectric constant decreases below a set threshold, the system switches to the holding stage, avoiding shrinkage or energy waste caused by premature or late holding. Through feedback adjustment of pressure and dielectric constant, the fill fullness of the blank's center area is improved, the timing of holding pressure is controlled accurately, and shrinkage of prismatic features is reduced. This, in conjunction with the overall process steps, improves product qualification rates.

[0073] When the pressure differential exceeds a first set threshold, the compression speed is reduced, slowing melt flow in higher-pressure areas and allowing lower-pressure areas more time to fill. Once the pressure differential falls below a second set threshold, the speed is restored to ensure overall compression efficiency. This adjustment method dynamically balances the pressure distribution of the melt in various areas of the cavity, preventing incomplete filling or structural defects caused by localized excessive or insufficient pressure. This, in conjunction with the pressure monitoring step, improves blank filling quality.

[0074] During the packing phase, a compensating pressure higher than the standard packing pressure is applied to the center area. This compensates for slower heat dissipation and greater material shrinkage in the center, which requires higher pressure to compensate. A compensating pressure lower than the standard packing pressure is applied to the edge areas, where heat dissipates faster and shrinks less. This lower pressure prevents structural deformation caused by excessive compression. This regional packing and packing cooling process coordinates shrinkage in each area, ensuring dimensional stability in key areas such as the prismatic grille features and improving product dimensional accuracy.

[0075] The compensation pressure in the center area is 1.1-1.2 times the standard holding pressure, while the compensation pressure in the edge area is 0.85-0.95 times the standard holding pressure. This range is determined based on the shrinkage characteristics of transparent and opaque materials and the differences in heat dissipation in the mold cavity. The pressure range in the center area effectively compensates for the larger shrinkage, while the pressure range in the edge area prevents excessive compression. These two factors, combined with the regional holding pressure design, further refine the holding parameters, keeping dimensional fluctuations in key grille areas within a reasonable range, and improving product dimensional consistency and pass rate.

[0076] The specific steps include:

[0077] Step 1: Mold cavity zone pressure monitoring

[0078] Piezoelectric pressure sensors are embedded in the four corners (A, B, C, D) and center (E) of the injection mold cavity to collect the resin filling pressure P in real time. A 、P B 、P C 、P D 、P E (Unit: MPa) Identify the pressure difference between the edge and center areas and detect flow imbalance.

[0079] Step 2: Adaptive adjustment of compression speed

[0080] Calculate the pressure gradient ΔP=|(P A +P B +P C +P D ) / 4-P EIf ΔP ≤ 4 MPa (determined based on PC material rheological experiments), the compression speed V = 1.0 mm / s is maintained. If ΔP > 4 MPa, the compression speed is automatically reduced to V = 0.5 mm / s until ΔP ≤ 2 MPa, after which it is restored. ΔP is the absolute value of the difference between the average pressure at the edge and the pressure at the center; V is the compression speed of the mold cavity. By preferentially filling the low-pressure area (usually the center), shrinkage caused by flow lag is eliminated.

[0081] Step 3: Real-time monitoring of dielectric constant

[0082] A dielectric sensor is embedded in the center of the core to measure the resin's dielectric constant, ε, and calculate the rate of change of the dielectric constant, K, as % / s (Δε / Δt), where Δt is the data sampling interval (0.1s). A sudden decrease in the rate of ε indicates the onset of solidification, thereby capturing the critical point of the resin phase transition.

[0083] Step 4: Intelligent switching between compression and holding pressure

[0084] When K≤-0.8% / s (determined by DSC testing of the PC glass transition point), that is, the dielectric constant decreases by 0.8% per second, the compression phase is immediately terminated and pressure holding is initiated. By capturing the starting point of resin solidification, premature pressure holding (resulting in shrinkage) and late pressure holding (resulting in energy waste) are avoided.

[0085] Step 5: Execute pressure packing in different areas

[0086] According to the five-zone pressure data in step 1, the pressure of each zone is dynamically adjusted during the pressure holding phase:

[0087] The holding pressure of the center area E = standard holding pressure × 1.15, and the holding pressure of the edge areas A / B / C / D = standard holding pressure × 0.9, to compensate for the shrinkage caused by slow heat dissipation in the center area.

[0088] This embodiment uses ΔP-driven variable speed compression to improve the filling fullness of the central area of ​​the white sheet, and controls the pressure holding trigger error within 0.3 seconds through dielectric feedback, which is 6 times more accurate than manual setting and reduces energy consumption by 11%. By maintaining pressure in different areas, the fluctuation of the position size of the grille's prismatic features is ≤±0.04mm, which is better than the industry standard and improves the pass rate of the two-color grille.

[0089] Although the above describes the specific embodiments of the present invention in conjunction with the accompanying drawings, it is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art on the basis of the technical solution of the present invention without creative work are still within the scope of protection of the present invention.

Claims

1. A two-color injection molding process grid, characterized in that: Includes white and black pieces; The white sheet is made of transparent material, the black sheet is made of opaque material, and the white sheet is located in front of the black sheet; The white sheet is designed with unequal material thickness, and the front surface of the black sheet has a brand logo installation area and a front camera installation area. The white sheet positions corresponding to the brand logo installation area and the front camera installation area are provided with cutting openings, and the brand logo installation area and the front camera installation area are exposed from the cutting opening positions.

2. The two-color injection molding process grid according to claim 1, characterized in that: A chamfer structure is provided at the parting line of the white piece.

3. The two-color injection molding process grid according to claim 1, characterized in that: The white sheet and the black sheet are fastened by gantry clamps and screws.

4. A process for preparing a two-color injection molding grid according to any one of claims 1 to 3, characterized in that: The following steps are involved: Injecting transparent melt into a single glue inlet point of the first cavity to form a white sheet semi-finished product; Close the injection molding machine nozzle and push the cavity to slightly move and compress the melt; Apply holding pressure and cool; Transfer the blank semi-finished product to the second cavity; Injecting opaque melt onto the back of the white semi-finished product to form a black sheet; The finished two-color grille is ejected.

5. The preparation process according to claim 4, wherein: The moving speed of the compressed melt is uniform.

6. The preparation process according to claim 4, wherein: The holding time of the holding pressure is dynamically adjusted according to the ambient temperature.

7. The preparation process according to claim 4, wherein: Also includes: Real-time monitoring of melt pressure in multiple areas of the cavity; Dynamically adjust the compression speed according to the pressure difference between the edge area and the central area; Real-time monitoring of the change rate of the melt dielectric constant; When the dielectric constant decrease rate is lower than the set threshold, it switches to the pressure holding stage.

8. The preparation process according to claim 7, wherein: When the pressure difference exceeds a first set threshold, the compression speed is reduced until the pressure difference falls below a second set threshold and then restored.

9. The preparation process according to claim 7, wherein: During the holding stage, a compensating pressure higher than the standard holding pressure is applied to the center area of ​​the cavity, and a compensating pressure lower than the standard holding pressure is applied to the edge area.

10. The preparation process according to claim 9, wherein: The compensation pressure in the central area is 1.1-1.2 times the standard holding pressure, and the compensation pressure in the edge area is 0.85-0.95 times the standard holding pressure.

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