A full-color printing method and a color workpiece based on an FDM forming mode

Abstract

The application discloses a full-color printing method based on an FDM forming mode and a color workpiece, and belongs to the field of FDM forming, and comprises the following processes: S1, a color 3D model of a color workpiece to be printed is established, and the color 3D model is divided into a plurality of two-dimensional slices to obtain slice information of the color 3D model; S2, based on the slice information of the color 3D model, a printing strategy of the color 3D model is determined; S3, according to the slice information of the color 3D model and the printing strategy, a colored cylindrical filament is obtained through a colored injection molding forming or a colored filament winding of a thermoplastic sheet; S4, according to the printing strategy of the color 3D model, printing parameters of an FDM printer are set; and S5, the colored cylindrical filament is subjected to FDM forming printing in a set printing parameter according to the printing strategy of the color 3D model, so that the color workpiece is obtained. The color printing rate, color resolution and color accuracy are improved.

Description

Technical Field

[0001] This invention belongs to the field of FDM molding and relates to a full-color printing method and a color workpiece based on FDM molding. Background Technology

[0002] 3D printing, as an emerging manufacturing technology, is based on computer digital technology. It involves three-dimensional modeling, model slicing, information processing, and layer-by-layer printing to ultimately form a three-dimensional entity. It integrates various modern technologies such as digital processing, computer technology, numerical control, and materials technology, and has been widely applied in various fields. Among them, Fused Deposition Modeling (FDM) technology, as one of the most representative and widely used technologies in the 3D printing field, has already shone brightly in many areas, including hobbyists, primary and secondary schools and universities, and small manufacturing workshops, due to its advantages such as low equipment cost, simple operation, and diverse material selection.

[0003] Color printing has significant applications in many fields, such as product design, education, healthcare, and cultural and creative industries. For example, in product design, color printing can more intuitively showcase the appearance and color effects of a product, helping designers communicate and interact better with clients. In education, color printing can create more vivid and engaging teaching models, improving teaching effectiveness. In healthcare, color printing can create human organ models with different color markings, facilitating medical teaching and surgical planning. In cultural and creative industries, color printing enables the creation of personalized artworks and decorations, meeting people's demand for personalized and creative products.

[0004] Traditional FDM printing has long been limited to monochrome output, mainly focusing on the layer-by-layer deposition of a single material to build a solid. Research on color 3D printing mainly involves coloring during or after printing, coloring the material before printing, or using multiple pure colors in combination for printing. These methods have a lag problem in color mixing, resulting in uneven color mixing, which makes it difficult to meet the increasingly diverse demands for refined, personalized, and artistic product appearance. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a full-color printing method and color workpiece based on FDM molding, which improves the printing speed, color resolution and color accuracy.

[0006] To achieve the above objectives, the present invention employs the following technical solution:

[0007] A full-color printing method based on FDM molding includes the following processes:

[0008] S1. Create a color 3D model of the color workpiece to be printed, and divide the color 3D model into multiple two-dimensional slices to obtain the slice information of the color 3D model.

[0009] S2, Based on the slice information of the color 3D model, determine the printing strategy of the color 3D model;

[0010] S3, based on the slicing information of the color 3D model and the printing strategy, colored cylindrical filaments are obtained by color injection molding or by coloring and spinning thermoplastic sheets.

[0011] S4, Set the printing parameters of the FDM printer according to the printing strategy of the color 3D model;

[0012] S5. Following the printing strategy of the color 3D model, the colored cylindrical filament is FDM printed using the set printing parameters to obtain the colored workpiece.

[0013] Preferably, the slicing information includes the size, position, layer thickness, number of layers, and color information of each two-dimensional slice.

[0014] Preferably, the printing strategy uses an outside-to-inside offset composite scanning path for printing, with segmented color printing outside the scanning path and reciprocating printing of the original color short side inside the scanning path.

[0015] Preferably, the process of coloring and winding thermoplastic sheet is as follows: the color data of the color 3D model is converted into data of the printing four-color mode, the color 3D model is decomposed into multiple color layers, each color layer corresponds to a printing four-color mode, and multiple color layers are combined into corresponding colors according to the slicing information and printing strategy of each two-dimensional slice, and then the thermoplastic sheet is matched and colored to obtain a colored thermoplastic sheet, and the colored thermoplastic sheet is spirally wound into a colored cylindrical filament.

[0016] Furthermore, inkjet printing or laser printing is used to color the thermoplastic sheet.

[0017] Furthermore, the laser printing process involves using laser scanning to form a latent charge image on the drum. Then, based on the slicing information of the color 3D model and the printing strategy, the corresponding color toner is adsorbed and transferred onto the thermoplastic sheet.

[0018] Furthermore, the inkjet printing process involves spraying four colors of ink—cyan, magenta, yellow, and black—onto a thermoplastic sheet to form ink droplets. After the four colors of ink are stacked on the thermoplastic sheet, a heating and fixing process is performed to firmly adhere the ink to the thermoplastic sheet.

[0019] Preferably, the coloring injection molding process is as follows: based on the slicing information of the color 3D model and the printing strategy, liquid colorants of different colors are prepared and mixed with the plastic melt in a predetermined ratio to obtain injection materials of different colors. The injection materials of different colors are injected into the cylindrical mold cavity according to the printing strategy and wait for solidification to form colored cylindrical filaments.

[0020] Preferably, the printing parameters are set as follows: layer height is 0.05mm~0.4mm, nozzle temperature is 180℃~250℃, printing speed is 30mm / s~100mm / s, and heated bed temperature is 30℃~110℃.

[0021] A colored workpiece obtained by the full-color printing method based on the aforementioned FDM molding method.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] This invention involves continuous layer-by-layer slicing of a color 3D model before color 3D printing to obtain various data for the slices. Colored cylindrical filaments are then obtained through colored injection molding or by coloring and spinning thermoplastic sheets. Using a single cylindrical filament, color 3D printing can be achieved, overcoming the limitations of traditional FDM printers such as multiple nozzles, limited color options, complex structures, and high costs. It also solves problems such as difficulty in changing colors and filaments in flexible materials and poor interlayer bonding, thus improving the speed of color printing and material utilization. The one-time-molded color workpiece can be preserved for a long time and has high artistic value, resisting fading, deformation, or damage. With high resolution and high precision, this invention can print models with rich details and smooth surfaces, accurately reproducing the color and texture of objects. It enables the creation of color models with various complex shapes and unique designs, meeting personalized needs. Attached Figure Description

[0024] Figure 1 This is a flowchart of the full-color printing method based on FDM molding according to the present invention;

[0025] Figure 2 This is a schematic diagram illustrating the preparation of the colored cylindrical filaments according to the present invention;

[0026] Figure 3 This is a schematic diagram of the printing device structure of the present invention.

[0027] Among them: 1-long strip thermoplastic sheet; 2-inkjet device; 3-filament winding device; 4-heated nozzle; 5-support; 6-exterior of colored workpiece; 7-interior of colored workpiece; 8-heated bed; 9-connecting rod. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Example 1

[0030] like Figure 1 The image shows the full-color printing method based on FDM molding described in this embodiment, which includes the following processes:

[0031] S1. Create a color 3D model of the color workpiece to be printed, and divide the color 3D model into multiple two-dimensional slices to obtain the slice information of the color 3D model.

[0032] S2, Based on the slice information of the color 3D model, determine the printing strategy of the color 3D model.

[0033] S3. Based on the slicing information of the color 3D model and the printing strategy, colored cylindrical filaments are obtained by color injection molding or by coloring and spinning thermoplastic sheets.

[0034] S4: Set the printing parameters of the FDM printer according to the printing strategy of the color 3D model.

[0035] S5. Following the printing strategy of the color 3D model, the colored cylindrical filament is FDM printed using the set printing parameters to obtain the colored workpiece.

[0036] Example 2

[0037] The full-color printing method based on FDM molding described in this embodiment includes the following processes:

[0038] S1. Obtain the structural data, color data, and material texture features of the color workpiece to be printed, establish a color 3D model of the color workpiece to be printed, input the color 3D model into the FDM printer, divide it into multiple two-dimensional slices, and obtain the slice information of the color 3D model.

[0039] S2, based on the slice information of the color 3D model, determines the printing strategy of the color 3D model, specifically:

[0040] The slicing information of the color 3D model includes the size, position, layer thickness, number of layers, and color information of each two-dimensional slice. The color information of each two-dimensional slice is obtained according to the color 3D model and represented in bitmap form to guide the heating nozzle to use the correct color at the corresponding position.

[0041] Set the time frame corresponding to the lowest plane and the highest plane of the color 3D model, as well as the maximum length and width, to determine whether the volume of the color 3D model exceeds the maximum printing volume of the FDM printer.

[0042] After computer processing, a printing strategy is determined, which includes the printing area, printing path, and printing parameters. The printing path is an offset composite scanning path from the outside in; that is, segmented color printing is used outside the scanning path, while the original color is used for repeated printing along the short side inside the scanning path. Specifically, the printed color solid model has colored exteriors, while the interior remains the original color.

[0043] Segmented color printing involves dividing the printing area into multiple regions, each printed using a different color. This method allows for complex color gradients and multi-color designs while avoiding color mixing and contamination.

[0044] Primary colors refer to basic colors that are not created by mixing with other colors; they are the foundation of all other colors. Primary color short-side reciprocating printing means that during the printing process, the heated nozzle 4 reciprocates along the short side of the paper or printing platform, and the printing material inside the heated nozzle 4 is the primary color.

[0045] S3. Based on the slicing information of the color 3D model and the printing strategy, colored cylindrical filaments are obtained by color injection molding or by coloring and spinning thermoplastic sheets.

[0046] The process of coloring and spinning thermoplastic sheets is as follows: Figure 2 As shown, the computer converts the color data of the 3D color model into printing four-color (magenta, cyan, yellow, and black) data and transmits it to the FDM printer. The FDM printer driver further processes this data, decomposing the 3D color model into multiple color layers, each corresponding to a printing four-color. Based on the color information of each two-dimensional slice and the printing path (the color information comes from the slice information, and the printing path comes from the printing strategy), multiple color layers are combined into corresponding colors, thereby matching and coloring the thermoplastic sheet. All two-dimensional slices are then sequentially applied to the thermoplastic sheet according to the printing order to obtain a colored thermoplastic sheet.

[0047] Methods for coloring thermoplastic sheets include, but are not limited to, inkjet printing and laser printing.

[0048] Laser printing uses laser scanning to form a charge latent image on the drum. Then, based on the slicing information of the color 3D model and the printing strategy, it adsorbs the corresponding color toner and transfers the toner onto the thermoplastic sheet.

[0049] The inkjet printing process is as follows: Based on the slicing information of the color 3D model and the printing strategy, in inkjet unit 2, the printhead of inkjet unit 2 precisely sprays four colors of ink—cyan, magenta, yellow, and black—onto a thermoplastic sheet according to computer instructions, forming tiny ink droplets. After the four colors of ink are sequentially superimposed on the thermoplastic sheet, a heating and fixing process is performed to firmly adhere the ink to the sheet. Due to the different dot distribution and concentration of each color, they interact and superimpose with each other, producing rich color levels and details, ultimately forming a colored thermoplastic sheet. For example, if the color information of the color 3D model contains blue, purple, black, and white, after computer processing, the color data is combined with the corresponding lengths, and blue, purple, black, and white are sequentially and quantitatively sprayed onto the thermoplastic sheet (the specific range depends on the actual amount required by the color 3D model). Finally, the thermoplastic sheet contains different color segments.

[0050] Colored thermoplastic sheets are spirally wound into colored cylindrical filaments at a 30°~60° angle.

[0051] Thermoplastic sheet materials include, but are not limited to, polylactic acid (PLA), acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene terephthalate (PETG), nylon (PA), and thermoplastic polyurethane (TPU).

[0052] The obtained colored thermoplastic sheet is spirally wound upwards at a specific angle to form a colored cylindrical filament. Compared with common FDM printing thermoplastic materials, this cylindrical filament contains different colors, enabling the printing of multiple colors from a single piece of material.

[0053] The coloring injection molding process is as follows: Based on the slicing information of the color 3D model and the printing strategy, the precise amount of liquid colorant is determined using a color chart or specialized software, combined with the amount of injection molding material. Different colored liquid colorants are then mixed with the molten plastic in predetermined proportions to obtain injection molding materials of different colors. For example, if the color information of the color 3D model includes blue, purple, black, and white, the amounts of blue, purple, black, and white colorants are prepared according to the corresponding color order and the corresponding proportions on the color chart. These are then mixed with the molten plastic in different proportions to obtain injection molding materials of different colors, thus obtaining the desired colors for the color 3D model. The injection molding process parameters are adjusted to ensure that the different colored injection molding materials are injected into the cylindrical mold cavity in a suitable order, pressure, and speed, ensuring that the colors are distributed within the cylinder according to the printing sequence. After solidification, the final product is a colored cylindrical filament.

[0054] S4, based on the printing strategy of the color 3D model, adjusts the printing platform of the FDM printer and sets printing parameters such as printing speed, nozzle temperature and layer height.

[0055] The printing parameters are set as follows: layer height is 0.05mm to 0.4mm, nozzle temperature is 180℃ to 250℃, printing speed is 30mm / s to 100mm / s, and heated bed temperature is 30℃ to 110℃.

[0056] S5. Following the printing strategy of the color 3D model, the colored cylindrical filament is FDM printed using the set printing parameters to obtain the colored workpiece.

[0057] Example 3

[0058] The above-mentioned full-color printing method using thermoplastic sheet coloring method is as follows: Figure 3 The printing device shown includes an inkjet unit 2, a filament winding unit 3, a heated nozzle 4, a support 5, a heated bed 8, and a connecting rod 9.

[0059] The thermoplastic sheet adopts a long strip thermoplastic sheet 1. The front end of the long strip thermoplastic sheet 1 is connected to the inkjet device 2. The inkjet device 2 sprays ink onto the long strip thermoplastic sheet 1 in a metered manner. After being colored, the front end of the long strip thermoplastic sheet 1 is fed into the filament winding device 3. After being processed by the filament winding device 3, the long strip thermoplastic sheet 1 is transformed into a colored cylindrical filament. The front end of the colored cylindrical filament is fed into the heating printhead 4, heated by the heating printhead 4, and output for printing.

[0060] A connecting rod 9 is connected to the bottom of the heated bed 8. The connecting rod 9 is connected to a moving device. The moving device controls the height and direction of the heated bed 8. The heating nozzle 4 is located directly above the heated bed 8. The heating nozzle 4 melts the colored cylindrical filament and first prints out the support 5. Then, it prints out the outer part 6 and the inner part 7 of the colored workpiece layer by layer. Finally, the colored workpiece is printed on the heated bed 8.

[0061] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0062] It should be understood that the above description is for illustrative purposes and not for limitation. Many embodiments and applications beyond the provided examples will become apparent to those skilled in the art upon reading the above description.

Claims

1. A full-color printing method based on FDM molding, characterized in that, The process includes the following: S1. Create a color 3D model of the color workpiece to be printed, and divide the color 3D model into multiple two-dimensional slices to obtain the slice information of the color 3D model. S2, Based on the slice information of the color 3D model, determine the printing strategy of the color 3D model; The printing strategy uses an outside-to-inside offset composite scanning path for printing. Segmented color printing is used outside the scanning path, while the original color short side is printed repeatedly inside the scanning path. S3, based on the slicing information of the color 3D model and the printing strategy, colored cylindrical filaments are obtained by coloring and winding thermoplastic sheets; The process of coloring and spinning thermoplastic sheets is as follows: the color data of the color 3D model is converted into the data of the printing four-color mode, the color 3D model is decomposed into multiple color layers, each color layer corresponds to a printing four-color mode, and according to the slicing information and printing strategy of each two-dimensional slice, the multiple color layers are combined into the corresponding colors, and then the thermoplastic sheet is matched and colored to obtain the colored thermoplastic sheet. The colored thermoplastic sheet is then spirally wound into colored cylindrical filaments. Coloring of thermoplastic sheets is achieved using inkjet printing or laser printing. The laser printing process is as follows: using laser scanning, a charge latent image is formed on the drum. Then, according to the slicing information of the color 3D model and the printing strategy, the corresponding color toner is adsorbed and the toner is transferred onto the thermoplastic sheet. The inkjet printing process is as follows: four colors of ink, namely cyan, magenta, yellow and black, are sprayed onto a thermoplastic sheet to form ink droplets. After the four colors of ink are stacked on the thermoplastic sheet, a heating and fixing process is carried out to make the ink firmly adhere to the thermoplastic sheet. S4, Set the printing parameters of the FDM printer according to the printing strategy of the color 3D model; S5. Following the printing strategy of the color 3D model, the colored cylindrical filament is FDM printed using the set printing parameters to obtain the colored workpiece.

2. The full-color printing method based on FDM molding as described in claim 1, characterized in that, The slicing information includes the size, location, layer thickness, number of layers, and color information of each two-dimensional slice.

3. The full-color printing method based on FDM molding as described in claim 1, characterized in that, Set the printing parameters as follows: layer height 0.05mm~0.4mm, nozzle temperature 180℃~250℃, printing speed 30mm / s~100mm / s, heated bed temperature 30℃~110℃.

4. A color workpiece obtained by a full-color printing method based on FDM molding as described in any one of claims 1-3.

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