A color mixing method and color mixing device for consumables for 3D printing

Abstract

The present invention discloses a color mixing method and a color mixing device for 3D printing consumables, and relates to the technical field of production of 3D printing consumables, including a color mixing module and an extrusion module. The color mixing module includes a central control module and a color mixing module, and the extrusion module includes an extrusion module connected to the color mixing module. The present invention uses a specific color mixing combination method for 3D printing consumables to add data of a target three-dimensional model to the production of 3D printing consumables in the production stage, so that the finished 3D printing consumables itself has the multi-color printing demand of the target hand-made model. During the multi-color printing process, an individual user only needs to use a single-nozzle 3D printer to print according to predetermined data to complete the printing and forming of the target hand-made model, thereby enabling the individual user to realize multi-color printing conveniently and at low cost, greatly expanding the application scope of the 3D printer, and making relatively small changes to the existing model 3D printer, which is conducive to promotion. The present invention can meet more color requirements of the objects to be printed.

Description

Technical Field

[0001] The present invention relates to the technical field of production of consumables for 3D printing, and in particular to a color mixing method and a color mixing device for consumables for 3D printing. Background Art

[0002] The published patent "A single-nozzle multi-color 3D printer and its multi-color printing method" with publication number CN105856561A is used as comparative document 1. It is pointed out in comparative document 1 that 3D printing is also called rapid prototyping, that is, putting data and raw materials into a 3D printer, and printing the product layer by layer through computer program control to finally form a finished product. Existing 3D printers include single-nozzle 3D printers and multi-nozzle 3D printers. A single-nozzle 3D printer supports the printing of a single color consumable, so that the printed product is a solid color; if multi-color printing is to be performed, the printing material can only be manually replaced when the color needs to be changed. Manually replacing materials requires active intervention from the user, which is highly dependent on the user, and the printing process is cumbersome, prone to defects or intervals, which has a great impact on the quality of the print.

[0003] Multi-nozzle 3D printers add additional print heads. Since multiple print heads are used, there is a problem of heating two print heads at the same time, resulting in energy loss. Moreover, the multiple print heads are independent of each other. When changing colors, the front print head needs to be moved away, and then another print head needs to be moved to continue printing. However, during the process of the two print heads taking over, their positions cannot be completely overlapped, causing problems in the front and back connection, thus affecting the exquisiteness of the product. For multi-color printing, the impact is even more serious when the colors are changed frequently.

[0004] The published patent "A 3D printer and printing method" with the publication number CN104290330B is used as reference document 2. Reference document 2 points out that rapid prototyping can be used in the prototyping process of three-dimensional objects, and the manufacturing of three-dimensional objects is realized through the conversion process of computer data. Generally, rapid prototyping mainly includes three types: stereolithography, laminated object manufacturing and selective deposition modeling.

[0005] The basic principle of selective deposition modeling is to slice a three-dimensional object layer by layer to obtain data information of each cross-section, and then manufacture the object based on this information. An existing selective deposition modeling is fused deposition modeling (FDM). The fused deposition modeling equipment includes an extrusion head, in which a wire feeding device can be set. After the extrusion head is heated by a heating element, the extrusion head can extrude molten fluid material, and the extruded material forms a solid structure after cooling and solidification.

[0006] In the prior art, there are technical solutions for 3D printers that can be used for the molding of colored objects. Based on the principle of the ratio of the three primary colors of red, green and blue, the mass ratio of the three different colors of silk materials in the heating chamber is adjusted to extrude the materials of the desired color. However, this 3D printer for the production of colored objects has a complex structure, high cost, and high requirements for the precision of the control system. In addition, the Chinese invention patent application with application number CN201410073577.5 discloses a feeding device that can be used for multiple silk materials, including at least two print boxes, at least two print heads, each print head receives consumables supplied by a print box, and also includes a switching device. When the material of one color is molded, the print head is moved to the switching device by the driving device, and the next color is printed. The 3D printer of this solution has a large number of print heads, a complex structure and a high cost, and needs to be further improved.

[0007] To sum up, individual users need to use a multi-nozzle 3D printer for printing in the process of multi-color printing. However, for individual users, the structure of the multi-nozzle 3D printer is complex and the cost is high, and the existing single-nozzle 3D printer only supports the printing of a single color consumable. This application aims to develop a method that can achieve multi-color printing through a single-nozzle 3D printer, so as to solve the problems of complex structure and high cost encountered by individual users in the process of multi-color printing. Summary of the invention

[0008] In order to overcome the above-mentioned shortcomings, the present invention aims to provide a technical solution for solving the above-mentioned problems by providing a color mixing method and a color mixing device for 3D printing consumables.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] A color mixing method for consumables for 3D printing, comprising a color mixing module and an extrusion module, wherein the color mixing module comprises a central control module and a color mixing module, and the extrusion module comprises an extrusion module connected to the color mixing module;

[0011] The operation of the central control module, color mixing module and extrusion module includes the following steps:

[0012] S100: The target three-dimensional model is imported into the central control module, and the target three-dimensional model is sliced. The target three-dimensional model is sliced ​​from bottom to top into a first single slice, a second single slice, ..., and an N1th single slice in order;

[0013] S200: Place the single piece in the plane coordinate system P1, set the peripheral contour line of the first single piece to L, obtain the color information of the starting point o on L and store it as c1, perform a traversal on L in one direction, and record the traversal path length l1, when the color of L changes, stop the traversal and record the position coordinate information M1, the first traversal is recorded as path L1, obtain the color information on M1 and store it as c2, start from point M1 and perform a second traversal along L in the same direction as the first traversal, and record the traversal path length l2, when the color of L changes, stop the traversal and record the position coordinate information M2, the second traversal is recorded as path L2, and so on, the peripheral contour line L is decomposed into a data group consisting of path L1, path L2, ..., path Ln;

[0014] The maximum outer diameter length of the first single piece is obtained and recorded as L0, and the maximum outer diameter width of the first single piece is obtained and recorded as W0;

[0015] S300: The color mixing module includes a color cylinder group, which includes an auxiliary material cylinder and a first color cylinder, a second color cylinder, ... and an nth color cylinder, wherein the consumable raw materials in the auxiliary material cylinder are used for printing operations of the support structure and the lining structure, the consumable color in the first color cylinder corresponds to the same color as c1, the consumable color in the second color cylinder corresponds to the same color as c2, and so on, the consumable color in the nth color cylinder corresponds to the same color as cn;

[0016] S400: the extrusion module extrudes the consumable raw material into a filament. The operation of the extrusion module includes n auxiliary material extrusions and m color material extrusions. During one auxiliary material extrusion process, the consumable raw material in the auxiliary material cylinder is added to the extrusion module. The extrusion module extrude the auxiliary material with a length of 2 (L0 + W0) + N2 (L0 + W0), where N2>2, and N2 is a positive integer;

[0017] After one extrusion of auxiliary materials is completed, color material extrusion is performed m times in sequence, where m≥2, and m is a positive integer. The consumable raw materials of the first color cylinder are added to the extrusion module, and wire extrusion of a length of l1 and color c1 is performed. The consumable raw materials of the second color cylinder are added to the extrusion module, and wire extrusion of a length of l2 and color c2 is performed. And so on. One closed loop is recorded as one color material extrusion. After m times of color material extrusion, auxiliary material extrusion is performed again until the extrusion of the first single piece of consumables is completed, and then the consumable extrusion operations of the second single piece, the third single piece, ..., and the N1th single piece are completed by analogy.

[0018] As a further solution of the present invention: during the slicing operation, the following steps are included:

[0019] S110: includes color proofreading from bottom to top, and after the color proofreading is passed, the first slicing and the second slicing are performed, the target three-dimensional model is first sliced ​​in the height direction with the color as the boundary, the printing line diameter of the 3D printer is set to Φ1, and the second slicing is performed according to Φ1, and the thickness of a single slice is set to d, where d=nΦ1, n≥1, and n is a positive integer.

[0020] As a further solution of the present invention: S110 further includes the following steps:

[0021] S120: If the color calibration fails, the target three-dimensional model is sliced ​​thinly, and n=1 and m=2 in the slices.

[0022] As a further solution of the present invention: S200 includes the following steps:

[0023] S210: During the traversal of the path Ln, when there are two colors in the height direction, the value of cn is the portion where the area of ​​the same color is greater than 50%.

[0024] As a further solution of the present invention: during the traversal of the path Ln, when there are multiple colors in the height direction, the value of cn is the part with the largest area of ​​the same color.

[0025] As a further solution of the present invention: when the color at the end point Q of the first single piece is the same as the color at the starting point o of the second single piece, the value of Mn skips point o.

[0026] As a further solution of the present invention: the color cylinder group also includes a plurality of color difference transition cylinders, the consumable raw materials in the color difference transition cylinders have a color between cn and cn-1, and when there are multiple colors at the position of cn, it is marked as a color mixing part, and the color difference transition cylinders are used for extrusion molding of the color mixing part.

[0027] As a further solution of the present invention: the color cylinder set also includes a color difference compensation module, and the color difference compensation module is used to calibrate the appearance color of the target three-dimensional model.

[0028] As a further solution of the present invention: In an embodiment of the present invention, the extrusion wire diameter of the wire is set to Φ2, wherein Φ2=nΦ1, n≥1, and n is a positive integer.

[0029] A color mixing device for consumables for 3D printing comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the above method when executing the computer program.

[0030] Compared with the prior art, the present invention has the following beneficial effects:

[0031] The present invention uses a specific color mixing and combination method for 3D printing consumables to add the data of the target three-dimensional model to the production of 3D printing consumables during the production stage, so that the finished 3D printing consumables themselves can meet the multi-color printing requirements of the target figure. During the multi-color printing process, individual users only need to use a single-nozzle 3D printer to print according to predetermined data to complete the printing and forming of the target figure, thereby enabling individual users to achieve multi-color printing conveniently and at low cost, greatly expanding the application scope of 3D printers, and requiring relatively little modification to existing 3D printer models, which is conducive to promotion. The present invention can meet more color requirements for objects to be printed. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic diagram of the process principle of FDM in the prior art;

[0033] Figure 2 is a structural stereogram of a target figure in one embodiment;

[0034] Figure 3 yes Figure 2 Schematic diagram of the slice of the target figure;

[0035] Figure 4 It is a schematic diagram of the routing path of the nozzle during the FDM operation in the prior art;

[0036] Figure 5 is a convenient schematic diagram of the first single piece in the present invention;

[0037] Figure 6 is a schematic diagram of the structure of a target three-dimensional model in one embodiment of the present invention;

[0038] Figure 7 is a schematic structural diagram of a target three-dimensional model in another embodiment of the present invention;

[0039] Figure 8 yes Figure 7 Partial view at R in the middle;

[0040] Fig. 9 It is a schematic diagram of the structure of the filament printing in the present invention;

[0041] Fig.10 It is the overall flow chart of the present invention;

[0042] Fig.11 This is a workflow diagram in one embodiment of the present invention;

[0043] Fig.12 is a work flow chart in another embodiment of the present invention;

[0044] The reference numerals and names in the figures are as follows:

[0045] Material rack-001, filament-002, temperature control unit-003, nozzle-004, printing platform-005, support structure-006, lining structure-007, cross-sectional profile-008, straight line printing-010. DETAILED DESCRIPTION

[0046] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] See also Figure 1-12 , a color mixing method for consumables for 3D printing, comprising a color mixing module and an extrusion module, the color mixing module comprising a central control module and a color mixing module, the extrusion module comprising an extrusion module connected to the color mixing module;

[0048] The operation of the central control module, color mixing module and extrusion module includes the following steps:

[0049] S100: The target three-dimensional model is imported into the central control module, and the target three-dimensional model is processed as follows Figure 3 The slicing process shown cuts the target 3D model into the first slice, the second slice, ..., the N1 slice in order from bottom to top. The combination of the N1 slices contains the complete size and color information of the target 3D model. The target 3D model can be obtained by combining the N1 slices.

[0050] S200: Figure 5 As shown, the single piece is placed in the plane coordinate system P1, and the peripheral contour line of the first single piece is set to L. The peripheral contour line L of the first single piece is the appearance display color of the target hand, so by obtaining the color of the peripheral contour line L, the appearance color information of the target hand can be obtained. In one embodiment, L coincides with the origin O of P1, and the color information of L at O ​​is obtained and stored as c1. A traversal is performed along L in a single direction, and the traversal path length l1 is recorded. When the color of L changes, the position coordinate information M1 (x1, y1) is recorded. The length l is obtained by one traversal. 1. The path with color c1 is recorded as path L1. Then, starting from point M1, a second traversal is performed along L in the same direction as the first traversal. The length of the traversal path is recorded as l2. When the color of L changes, the position coordinate information M2 (x2, y2) is recorded. The second traversal obtains a path with a length of l2 and a color of c2, which is recorded as path L2. By analogy, the peripheral contour line L is decomposed into a data group consisting of path L1, path L2, ..., path Ln. The N1 single pieces are traversed in sequence, so that the path information of the peripheral contour lines L of all single pieces can be obtained.

[0051] The maximum length of the first single piece is obtained and recorded as L0, and the maximum width of the first single piece is obtained and recorded as W0;

[0052] S300: The color mixing module includes a color cylinder group, which includes an auxiliary material cylinder, a first color cylinder, a second color cylinder, ... and an nth color cylinder, wherein the consumable raw materials in the auxiliary material cylinder are used for printing operations of the support structure 006 and the lining structure 007, the consumable color in the first color cylinder corresponds to the same color as c1 and the consumable in the first color cylinder is used for extrusion molding of L1, the consumable color in the second color cylinder corresponds to the same color as c2 and the consumable in the second color cylinder is used for extrusion molding of L2, and so on, the color cylinder group includes all color types of the target three-dimensional model;

[0053] S400: The extrusion module extrudes the consumable raw materials into Figure 1 The filament 002 shown in the figure, in the extrusion operation of the extrusion module, the sequence and length of the 3D printing filaments of different colors are designed, such as Figure 4 As shown, first, an auxiliary material extrusion is performed, and the consumable raw materials of the auxiliary material cylinder are added to the extrusion module, and the auxiliary material with a length of 2 (L0 + W0) + N2 (L0 + W0) is extruded, where N2>2, and N2 is a positive integer. After one auxiliary material extrusion is completed, m color material extrusions are performed, m≥2, and m is a positive integer. During one color material extrusion, a wire with a length of l1 and a color of c1 is first extruded, and then a wire with a length of l2 and a color of c2 is extruded successively. Completion of a printing closed loop is recorded as one color material extrusion, and so on. After m color material extrusions are performed, another auxiliary material extrusion is performed, and the cycle is repeated until the consumable extrusion of the first single piece is completed, and then the consumable extrusion operations of the second single piece, the third single piece, ..., and the N1th single piece are completed by analogy, thereby completing the consumable extrusion operation of the target figure. The above-mentioned N2 and m are set to fixed values, and N2 is Figure 4 The number of straight lines printed as shown in , m is the printing accuracy of the cross-sectional profile 008, and individual users can print according to the factory preset value of the consumables during the printing process, and print the target three-dimensional model according to the preset path;

[0054] FDM technology has become the preferred process for consumer-grade 3D printing (3D printing for individual users) due to its low cost and threshold. FDM heats and melts various filaments (such as PLA, ABS, etc.) and then forms them cumulatively. Specifically, through the control of a computer or embedded software and hardware, the nozzle moves in the XOY plane according to the cross-sectional profile information of the product. At the same time, the material is sent to the nozzle under the action of the extruder to be heated and melted into a semi-liquid state, and then extruded, cooled and solidified. After completing a layer, the nozzle will move up a certain distance (or the printing platform will drop a certain distance), and the reciprocating cycle will eventually form the required three-dimensional part product. The process principle of FDM is shown in Figure 1;

[0055] The process of printing the target model shown in FIG2 by a single-nozzle 3D printer includes the following steps: using the slicing software to slice the target three-dimensional model of the target model into the following Figure 3 The sliced ​​target 3D model data is imported into the control system of the 3D printer, and then the printer prints layer by layer according to the slice information. During the single-layer printing process, the nozzle routing path is as follows Figure 4 As shown, in order to ensure that the cross-sectional profile 008 can be stably printed on the printing platform during the printing process, the single-layer printing includes product printing (i.e., printing of the cross-sectional profile 008) and auxiliary material printing. The auxiliary material printing includes a support structure 006 added to the outer circle of the cross-sectional profile 008 and an inner lining structure 007 added to the inner circle of the cross-sectional profile 008. The support structure 006 is used to provide printing support for the cross-sectional profile 008, and the inner lining structure 007 is used to provide force support for the interior of the cross-sectional profile 008.

[0056] In the single-layer printing process, the 3D printer first prints the auxiliary materials, then Figure 4 As shown, a frame is printed along the path of a1, b1, c1, d1, a1, and then spaced and parallel straight lines are printed 010 in the frame in the order of a2-b2, b3-a3, a4-b4... The support structure 006 and the lining structure 007 are printed and formed by multiple horizontal and vertical straight line printings 010. After the support structure 006 and the lining structure 007 are printed, the product is printed. During the printing process of the product, the printing of the cross-sectional profile 008 needs to be more dense. In addition, in order to save raw materials and facilitate the peeling of the support structure 006 after the target figure is printed, the support structure 006 is generally The printing density of the support structure 006 and the lining structure 007 is smaller than that of the cross-sectional profile 008. Therefore, the number of printing circles of the cross-sectional profile 008 is more frequent than that of the support structure 006 and the lining structure 007. In the process of printing a single layer of the support structure 006 and the lining structure 007, when printing the auxiliary material once, it is necessary to print the cross-sectional profile 008 multiple times. The target figure is formed by printing and stacking multiple layers of the support structure 006 and the lining structure 007 and the cross-sectional profile 008. The printing of the auxiliary material during the printing process is used to support the formation of the support structure 006 and the lining structure 007.

[0057] The printing process of multi-color target figures involves the combination of printing consumables of various colors. The applicant innovates the color mixing of 3D printing consumables. In the production process of 3D printing consumables, a specific color mixing and combination method of 3D printing consumables is used to enable individual users to print 3D models of figures of various colors through a single-nozzle 3D printer.

[0058] First, build a three-dimensional model of the target. The target three-dimensional model is built by three-dimensional scanning or three-dimensional modeling. Three-dimensional scanning uses a 3D scanner to scan the target hand-made model (as described in the published patent with announcement number CN107547771B). Three-dimensional modeling is to build a model through three-dimensional modeling software to generate a model such as Figure 2 The target three-dimensional model of the target figure shown, after the individual user builds the target three-dimensional model, the target three-dimensional model data is sent to the consumables manufacturer (i.e., the applicant);

[0059] S100: The target three-dimensional model is imported into the central control module, and the target three-dimensional model is processed as follows Figure 3 The slicing process shown cuts the target 3D model into the first slice, the second slice, ..., the N1 slice in order from bottom to top. The combination of the N1 slices contains the complete size and color information of the target 3D model. The target 3D model can be obtained by combining the N1 slices.

[0060] S200: Figure 5 As shown, the first single piece is placed in the plane coordinate system P1, and the peripheral contour line of the first single piece is set to L. The peripheral contour line L of the first single piece is the appearance display color of the target figure, so by obtaining the color of the peripheral contour line L, the appearance color information of the target figure can be obtained. In one embodiment, L coincides with the origin O of P1, and the color information of L at O ​​is obtained and stored as c1. A traversal is performed along L in a single direction, and the traversal path length l1 is recorded. When the color of L changes, the position coordinate information M1 (x1, y1) is recorded. A path with a length of l1 and a color of c1 is obtained by one traversal. The path is L1, and then a second traversal is performed along L from point M1 in the same direction as the first traversal, and the traversal path length l2 is recorded. When the color of L changes, the position coordinate information M2 (x2, y2) is recorded. The second traversal obtains a path with a length of l2 and a color of c2, which is recorded as path L2. And so on, where the sum of l1+l2+…+ln can obtain the perimeter of a single piece, and the perimeter contour line L is decomposed into a data group consisting of path L1, path L2, …, path Ln. The N1 single pieces are traversed in turn, so that the path information of the perimeter contour lines L of all single pieces can be obtained;

[0061] The maximum length of the first single piece is obtained and recorded as L0, and the maximum width of the first single piece is obtained and recorded as W0;

[0062] S300: The color mixing module includes a color cylinder group, which includes an auxiliary material cylinder, a first color cylinder, a second color cylinder, ... and an nth color cylinder, wherein the consumable raw materials in the auxiliary material cylinder are used for printing operations of the support structure 006 and the lining structure 007, the consumable color in the first color cylinder corresponds to the same color as c1 and the consumable in the first color cylinder is used for printing L1, the consumable color in the second color cylinder corresponds to the same color as c2 and the consumable in the second color cylinder is used for printing L2, and so on, the color cylinder group includes all color types of the target three-dimensional model;

[0063] S400: The extrusion module extrudes the consumable raw materials into Figure 1 The filament 002 shown in the figure, in the extrusion operation of the extrusion module, the sequence and length of the 3D printing filaments of different colors are designed, such as Figure 4 As shown, firstly, an auxiliary material extrusion is performed, and the consumable raw materials of the auxiliary material cylinder are added to the extrusion module, and the auxiliary material with a length of 2 (L0 + W0) + N2 (L0 + W0) is extruded, where N2>2, and N2 is a positive integer. After one auxiliary material extrusion is completed, m color material extrusions are performed, m≥2, and m is a positive integer. During one color material extrusion, a wire with a length of l1 and a color of c1 is first extruded, and then a wire with a length of l2 and a color of c2 is extruded successively. The completion of a printing closed loop is recorded as one color material extrusion. A printing closed loop at means that the length of the color material extrusion is equal to the circumference of the single piece, that is, one circle of printing is completed during the color material printing operation, and so on, after m times of color material extrusion (that is, the length of the color material extrusion can complete the printing operation of m circles), another auxiliary material extrusion is performed, and the cycle is repeated until the extrusion of the consumable material of the first single piece is completed, and then the consumable material extrusion operation of the second single piece, the third single piece, ..., and the N1th single piece is completed by analogy, thereby completing the consumable material extrusion operation of the target hand. The above-mentioned N2 and m are set to fixed values, and N2 is Figure 4 The number of straight line prints shown in depends on the size and quality of the target 3D model. The larger the quality of the target 3D model and the larger the size of the target 3D model, the greater the support force required, so the value of N2 will also be larger. m is the printing accuracy of the cross-sectional profile 008. Individual users can print according to the factory preset value during printing, and the target 3D model can be printed according to the preset path.

[0064] The present invention uses a specific color mixing and combination method for 3D printing consumables to add the data of the target three-dimensional model to the production of 3D printing consumables during the production stage, so that the finished 3D printing consumables themselves can meet the multi-color printing requirements of the target figure. During the multi-color printing process, individual users only need to use a single-nozzle 3D printer to print according to predetermined data to complete the printing and forming of the target figure, thereby enabling individual users to achieve multi-color printing conveniently and at low cost, greatly expanding the application scope of 3D printers, and requiring relatively little modification to existing 3D printer models, which is conducive to promotion. The present invention can meet more color requirements for objects to be printed.

[0065] In the embodiment of the present invention, the slicing operation process includes the following steps:

[0066] S110: including color proofreading from bottom to top, performing primary slicing and secondary slicing after the color proofreading is passed, performing primary slicing on the target three-dimensional model in the height direction with the color as the boundary, setting the printing line diameter of the 3D printer to Φ1, performing secondary slicing according to Φ1, and setting the thickness of a single slice to d, wherein d=nΦ1, n≥1, and n is a positive integer;

[0067] In order to facilitate traversal and obtain the color of the peripheral contour line L, it is necessary to control the color of the single piece in the vertical direction to be consistent, that is, the color of the same single piece in the height direction is consistent, so as to avoid the problem of color confusion in the process of traversal and color acquisition. Figure 6 As shown, color proofreading is to check whether there is obvious color stratification in the vertical direction in part of the target 3D model. If the target 3D model can be obviously stratified according to color, it means that the color proofreading has passed. In the process of slicing the target 3D model, if the color of the target 3D model is inconsistent from top to bottom at h1, then slice it once from h1, and then slice p1 twice. If the color of the target 3D model is inconsistent from top to bottom at h2, then slice it once from h2, and then slice p2 twice. The entire slicing operation is completed by analogy, where d=nΦ1, where n is n auxiliary material extrusions. When n is equal to 3, auxiliary material extrusion is performed once, and then color material extrusion is performed m times. This action is repeated three times, and auxiliary material extrusions are performed three times, and color material extrusions are performed 3 times m times. In this way, the target 3D model can be better printed and restored during the printing process, and the printing accuracy is guaranteed while simplifying the printing data.

[0068] In the embodiment of the present invention, S110 further includes the following steps:

[0069] S120: If the color calibration fails, the target 3D model is sliced ​​thinly, where n=1 and m=2 in the slices;

[0070] like Figure 7 As shown in Figure 2, the vertical color stratification in some target 3D models is not obvious, such as Figure 7 The middle edge curve h3 has two different colors above and below. After being sliced, M5 will contain two colors in the height direction. According to step S110, the color calibration mode fails, and the first slice cannot be performed in the height direction. Then, the target three-dimensional model is directly sliced. Through the refined slicing, the target three-dimensional model is refined and divided into multiple single pieces in a similar differential form. The multiple single pieces can approach the target three-dimensional model in a manner similar to integration. The appearance colors and contours of the multiple single pieces are slightly different from the original target three-dimensional model, but are close to the original target three-dimensional model.

[0071] In the actual printing process, the output of the extrusion module includes n auxiliary material extrusions and m color material extrusions, wherein the auxiliary material is extruded once, and after the auxiliary material extrusion is completed, the color material is extruded m times, and then the auxiliary material is extruded once, and the color material is extruded m times again, and then the auxiliary material is extruded once, and then the color material is extruded m times, and then the auxiliary material is extruded once, and then the color material is extruded m times, and so on. Fig. 9 As shown, a printing operation is performed on plane p6, firstly, the support structure 006 and the lining structure 007 are printed once, and then the cross-sectional profile 008 is printed once on the support structure 006 and the lining structure 007, and then the support structure 006 and the lining structure 007 are printed twice on this basis, and then the cross-sectional profile 008 is printed twice on the basis of the second printing of the support structure 006 and the lining structure 007, and the cycle is repeated to complete the printing of the first single piece, and the printing of the N1th single piece is completed by analogy;

[0072] When n=1 and m=2 in the thin slice, it means that the thickness of a single piece only allows two color material extrusions, that is, after the first auxiliary material extrusion is completed, the second color material extrusion is performed, and the first single piece printing is completed;

[0073] The differentiation of the original target three-dimensional model is made more precise, the printing error is reduced, and the combination of multiple single pieces is closer to the original target three-dimensional model. At the same time, the printing density of the cross-sectional profile 008 is ensured to be greater than the printing density of the support structure 006 and the lining structure 007, which facilitates the demoulding of the support structure 006;

[0074] Here, one color material extrusion refers to the alternating discharge of the first color cylinder, the second color cylinder, ... and the nth color cylinder, etc., and the completion of one color material extrusion means a printing closed loop.

[0075] In the embodiment of the present invention, S200 includes the following steps:

[0076] S210: During the traversal of the path Ln, when there are two colors in the height direction, the value of cn is the portion where the area of ​​the same color is greater than 50%;

[0077] like Figure 8As shown in the figure, after the target 3D model is sliced, during the traversal of the path Ln, M6 contains two colors in the height direction, and there will be confusion in the color selection process of cn. Therefore, when the color is selected upward and downward at the position of M6, if the area of ​​a certain color at M6 accounts for more than 50%, then the color is used as the value of cn, so that the single slice has a higher degree of restoration of the original target 3D model, as shown in the figure. Figure 8 As shown, it is a schematic diagram after refinement and slicing, so the size of M6 here should also be enlarged accordingly. M6 should be understood as an interval value, which serves as the minimum traversal unit in the traversal process of the path Ln.

[0078] In the embodiment of the present invention, during the traversal of the path Ln, when there are multiple colors in the height direction, the value of cn is the part with the largest area of ​​the same color;

[0079] In some embodiments, during the traversal of the path Ln, some points contain multiple colors in the height direction, and confusion may occur in the color selection process of cn. Therefore, when selecting colors upward and downward at the position of cn, the value of cn is the part with the largest area of ​​the same color.

[0080] In the embodiment of the present invention, when the color at the end point Q of the first single piece is the same as the color at the starting point o of the second single piece, the value of Mn skips point o;

[0081] like Figure 8 As shown, point Q is the printing end point of the first single piece and also the printing start point of the second single piece. If the color at the end point Q of the first single piece is the same as the color at the starting point o of the second single piece, it means that printing can continue, that is, the extrusion module does not need to replace the color barrel, and the extruded color is the same, which means that Mn can be traversed backward until the color changes. Similarly, if the color of the end point of the previous single piece is the same as the starting point of the next single piece, continuous printing can be carried out, thereby simplifying the process.

[0082] In the embodiment of the present invention, the color cylinder group further includes a plurality of color difference transition cylinders, the consumable raw material in the color difference transition cylinders has a color between cn and cn-1, and when there are multiple colors at the position of cn, it is marked as a color mixing part, and the color difference transition cylinders are used for extrusion molding of the color mixing part;

[0083] In some embodiments, during the traversal of path Ln, some points contain multiple colors in the height direction, and confusion will occur in the color picking process of cn. Therefore, the color picking mark at the position of cn is marked as a color mixing part, and the color material of the color mixing part is extruded and picked up from the color difference transition module. The color picking of the color difference transition is between cn and cn-1, making the color transition between cn and cn-1 more natural.

[0084] In the embodiment of the present invention, the color cylinder set further includes a color difference compensation module, and the color difference compensation module is used to calibrate the appearance color of the target three-dimensional model.

[0085] In actual use, the cross-sectional profile 008 will partially intersect with the support structure 006 and the lining structure 007. Since the support structure 006 and the lining structure 007 use auxiliary materials in the intersection portion, the appearance color of the cross-sectional profile 008 will be affected, and there will be a slight color difference in the overlapping portion of the cross-sectional profile 008 and the support structure 006 and the lining structure 007. Therefore, a color difference compensation module is set. When the actual printed model is inconsistent with the color appearance shown in the target three-dimensional model, the color adjustment of the color cylinder group is proofread through the color difference compensation module to make the target three-dimensional model more similar to the actual model.

[0086] In the embodiment of the present invention, the extrusion wire diameter of the wire is set to Φ2, where Φ2=nΦ1, n≥1, and n is a positive integer;

[0087] It is convenient for proportional conversion of extrusion length and printing length, and at the same time, the wire diameter of the wire is proportionally enlarged, which is conducive to storage. Too thin wire is not conducive to storage and transportation.

[0088] In an embodiment of the present invention, the extrusion module includes a print head having the same print line diameter as the 3D printer;

[0089] The extruded filament can be directly used for printing, which is more convenient to use.

[0090] In the embodiment of the present invention, the density of the consumable raw material used in the auxiliary material cylinder is smaller than that of the first color cylinder, the second color cylinder, ... and the nth color cylinder;

[0091] This facilitates demoulding of the supporting structure 006.

[0092] A color mixing device for consumables for 3D printing comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the color mixing method when executing the computer program.

[0093] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

Claims

1. A method for mixing colors of consumables for 3D printing, characterized in that: It includes a color mixing module and an extrusion module, the color mixing module includes a central control module and a color mixing module, and the extrusion module includes an extrusion module connected to the color mixing module; The operation of the central control module, color mixing module and extrusion module includes the following steps: S100: The target three-dimensional model is imported into the central control module, and the target three-dimensional model is sliced. The target three-dimensional model is sliced ​​from bottom to top into a first single slice, a second single slice, ..., and an N1th single slice in order; S200: Place the single piece in the plane coordinate system P1, set the peripheral contour line of the first single piece to L, obtain the color information of the starting point o on L and store it as c1, perform a traversal on L in one direction, and record the traversal path length l1, when the color of L changes, stop the traversal and record the position coordinate information M1, the first traversal is recorded as path L1, obtain the color information on M1 and store it as c2, start from point M1 and perform a second traversal along L in the same direction as the first traversal, and record the traversal path length l2, when the color of L changes, stop the traversal and record the position coordinate information M2, the second traversal is recorded as path L2, and so on, the peripheral contour line L is decomposed into a data group consisting of path L1, path L2, ..., path Ln; The maximum outer diameter length of the first single piece is obtained and recorded as L0, and the maximum outer diameter width of the first single piece is obtained and recorded as W0; S300: The color mixing module includes a color cylinder group, which includes an auxiliary material cylinder and a first color cylinder, a second color cylinder, ... and an nth color cylinder, wherein the consumable raw materials in the auxiliary material cylinder are used for printing operations of the support structure and the lining structure, the consumable color in the first color cylinder corresponds to the same color as c1, the consumable color in the second color cylinder corresponds to the same color as c2, and so on, the consumable color in the nth color cylinder corresponds to the same color as cn; S400: the extrusion module extrudes the consumable raw material into a filament. The operation of the extrusion module includes n auxiliary material extrusions and m color material extrusions. During one auxiliary material extrusion process, the consumable raw material in the auxiliary material cylinder is added to the extrusion module. The extrusion module extrude the auxiliary material with a length of 2 (L0 + W0) + N2 (L0 + W0), where N2>2, and N2 is a positive integer; After one extrusion of auxiliary materials is completed, color material extrusion is performed m times in sequence, where m≥2, and m is a positive integer. The consumable raw materials of the first color cylinder are added to the extrusion module, and wire extrusion of a length of l1 and color c1 is performed. The consumable raw materials of the second color cylinder are added to the extrusion module, and wire extrusion of a length of l2 and color c2 is performed. And so on. One closed loop is recorded as one color material extrusion. After m times of color material extrusion, auxiliary material extrusion is performed again until the extrusion of the first single piece of consumables is completed, and then the consumable extrusion operations of the second single piece, the third single piece, ..., and the N1th single piece are completed by analogy. The slicing process includes the following steps: S110: includes color proofreading from bottom to top, and after the color proofreading is passed, the first slicing and the second slicing are performed, the target three-dimensional model is first sliced ​​in the height direction with the color as the boundary, the printing line diameter of the 3D printer is set to Φ1, and the second slicing is performed according to Φ1, and the thickness of a single slice is set to d, where d=nΦ1, n≥1, and n is a positive integer. S110 also includes the following steps: S120: If the color calibration fails, the target three-dimensional model is sliced ​​thinly, and n=1 and m=2 in the slices.

2. A method for mixing colors of consumables for 3D printing according to claim 1, characterized in that: S200 includes the following steps: S210: During the traversal of the path Ln, when there are two colors in the height direction, the value of cn is the portion where the area of ​​the same color is greater than 50%.

3. A method for mixing colors of consumables for 3D printing according to claim 1, characterized in that: When there are multiple colors in the height direction during the traversal of path Ln, the value of cn is the part with the largest area of ​​the same color.

4. A method for mixing colors of consumables for 3D printing according to claim 1, characterized in that: When the color at the end point Q of the first single piece is the same as the color at the starting point o of the second single piece, the value of Mn skips point o.

5. A method for mixing colors of consumables for 3D printing according to claim 1, characterized in that: The color cylinder group also includes a plurality of color difference transition cylinders. The consumable raw materials in the color difference transition cylinders have colors between cn and cn-1. When there are multiple colors at the cn position, it is marked as a color mixing part. The color difference transition cylinders are used for extrusion molding of the color mixing part.

6. A method for mixing colors of consumables for 3D printing according to claim 1, characterized in that: The color cylinder set also includes a color difference compensation module, which is used to calibrate the appearance color of the target three-dimensional model.

7. A method for mixing colors of consumables for 3D printing according to any one of claims 1 to 6, characterized in that: The extruded wire diameter of the wire is set to Φ2, where Φ2=nΦ1, n≥1, and n is a positive integer.

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