Three-dimensional printed object and printing method thereof

Abstract

The invention discloses a three-dimensional printing object and a printing method thereof. The printing method of the three-dimensional printing object comprises the steps that whether the edge of a current basic printing layer correspondingly protrudes out of the edge of a previous basic printing layer or not is judged; if the edge of the current basic printing layer does not correspondingly protrude out of the edge of the previous basic printing layer, multiple current outer wall color layers are obtained through laminated printing in the edge area of the printing face of the to-be-printed object, the current basic printing layer is obtained through printing in the middle area of the printing face, and a layer-adding printing object is obtained; wherein the lamination thickness of the current outer wall color layers is equal to the thickness of the current basic printing layer; and taking the layer-adding printing object as a new object to be printed, and circularly executing the judgment step until a three-dimensional printing object is printed and obtained. By means of the method, the finer outer wall color layer is used for expressing finer and more real color expression, and the color presentation precision and the color rendition degree are improved.

Description

Technical Field

[0001] This application is applied to the technical field of 3D printing, especially a 3D printed object and its printing method. Background Art

[0002] 3D printing technology is a kind of additive manufacturing technology. With the development of 3D printing technology, the continuous maturity of 3D printing technology has promoted a great leap in related manufacturing industries.

[0003] Currently, 3D printing technology often uses the fused deposition modeling (FDM) technology to print layer by layer.

[0004] However, the 3D printed object printed by this technology has low surface accuracy and poor color restoration. Summary of the Invention

[0005] This application provides a 3D printed object and its printing method to solve the problems of low surface accuracy and poor color restoration of 3D printed objects.

[0006] To solve the above technical problems, this application provides a printing method for a 3D printed object, including obtaining the printing trajectory of the current outer wall color layer and the printing trajectory of the current base printing layer; judging whether the edge of the current base printing layer corresponds to protruding beyond the edge of the previous base printing layer; if the edge of the current base printing layer does not correspond to protruding beyond the edge of the previous base printing layer, layer-by-layer printing is respectively performed in the edge area of the printing surface of the object to be printed to obtain multiple layers of the current outer wall color layer and the current base printing layer is printed in the middle area of the printing surface to obtain an additive printed object; wherein, the stacked thickness of the multiple layers of the current outer wall color layer is equal to the thickness of the current base printing layer, and the edge area is arranged to fit around the middle area; taking the additive printed object as the new object to be printed, and looping through the steps of judging whether the edge of the current base printing layer corresponds to protruding beyond the edge of the previous base printing layer and subsequent steps until a 3D printed object is obtained.

[0007] Among them, the steps of obtaining a laminated printed object by laminating and printing multiple current outer wall color layers in the edge area of the printing surface of the object to be printed and printing the current basic printing layer in the middle area of the printing surface include: laminating and printing multiple current outer wall color layers in the edge area of the printing surface of the object to be printed until the cumulative thickness of the multiple laminated current outer wall color layers reaches one-half of the thickness of the current basic printing layer; printing the current basic printing layer in the middle area of the printing surface of the object to be printed; laminating and printing the current outer wall color layer again on the side of the printed current outer wall color layer away from the printing surface until the cumulative thickness of the multiple laminated current outer wall color layers reaches the thickness of the current basic printing layer to obtain a laminated printed object; among them, the side of the multiple laminated current outer wall color layers close to the current basic printing layer is attached to the current basic printing layer.

[0008] Among them, the steps of obtaining a laminated printed object by laminating and printing multiple current outer wall color layers in the edge area of the printing surface of the object to be printed and printing the current basic printing layer in the middle area of the printing surface include: laminating and printing multiple current outer wall color layers in the edge area of the printing surface of the object to be printed until the cumulative thickness of the multiple laminated current outer wall color layers reaches the thickness of the current basic printing layer; in the middle area of the printing surface of the object to be printed, printing the current basic printing layer by attaching to the multiple current outer wall color layers to obtain a laminated printed object; among them, the side of the multiple laminated current outer wall color layers close to the current basic printing layer is flush.

[0009] Among them, the steps of obtaining a laminated printed object by laminating and printing multiple current outer wall color layers in the edge area of the printing surface of the object to be printed and printing the current basic printing layer in the middle area of the printing surface further include: printing the current fixed color layer in the edge area of the current outer wall color layer on the side of the laminated printed object away from the printing surface; among them, the side of the current fixed color layer close to the middle area protrudes from the side of the current outer wall color layer close to the middle area so that the current fixed color layer is attached to the side of the current basic printing layer away from the printing surface.

[0010] Among them, the steps of determining whether the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer further include: if the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer, alternately laminating and printing the current outer wall transmissive printing layer and the current fixed color layer in the edge area of the printing surface of the object to be printed; and printing the current basic printing layer in the middle area of the printing surface of the object to be printed to obtain a laminated printed object.

[0011] Among them, the steps of obtaining the object to be printed include: obtaining the printing trajectory of the bottom printing layer, and printing the bottom printing layer based on the printing trajectory of the bottom printing layer; integrally printing the first end face color layer on one side of the bottom printing layer to obtain the object to be printed.

[0012] Among them, taking the object with incremental printing as the new object to be printed, and looping through the steps of determining whether the edge of the current basic printing layer protrudes corresponding to the edge of the previous basic printing layer and the subsequent steps until the step of printing the three-dimensional printing object further includes: integrally printing the second end face color layer on the side of the object with incremental printing away from the bottom printing layer to obtain the three-dimensional printing object.

[0013] Among them, the steps of obtaining the printing trajectory of the current outer wall color layer and the printing trajectory of the current basic printing layer include: obtaining the overall shape of the three-dimensional printing object; slicing the overall shape based on the thickness of the basic printing layer to obtain the printing trajectories of multiple layer structures of the three-dimensional printing object; shrinking the printing trajectories of each layer structure by a preset distance to correspondingly obtain the printing trajectories of each basic printing layer, and correspondingly obtaining the printing trajectories of each color layer based on the shrunk preset distance.

[0014] Among them, the steps of respectively laminating and printing multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed and printing the current basic printing layer in the middle area of the printing surface include: respectively using the stereolithography inkjet printing technology to laminate and print multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed and using the fused deposition modeling technology to print the current basic printing layer in the middle area of the printing surface.

[0015] To solve the above technical problems, the present application also provides a three-dimensional printing object, which is printed by the printing method of the three-dimensional printing object in any one of the above, and includes: a printing main body, the printing main body includes multiple layers of basic printing layers that are laminated and attached; a color shell, the color shell is arranged to wrap the exposed side of the printing main body, and the color shell includes multiple layers of outer wall color layers that are laminated and attached; among them, the outer wall color layer and the basic printing layer are laminated relative to the same horizontal layer, and the thickness of the outer wall color layer is less than the thickness of the basic printing layer.

[0016] Among them, the three-dimensional printed object includes one or more of a vertical side wall, an inner inclined side wall, and an overhanging side wall; the sides of the multiple layers of basic printing layers corresponding to the vertical side wall that are away from the printing body are flush; the sides of the multiple layers of outer wall color layers corresponding to the vertical side wall that are away from the printing body are flush; in the direction from the bottom surface to the top surface of the three-dimensional printed object, the edges of the multiple layers of basic printing layers corresponding to the inner inclined side wall that are away from the printing body are gradually shortened layer by layer, and the edges of the multiple layers of outer wall color layers corresponding to the inner inclined side wall that are away from the printing body are inclined layer by layer toward the side close to the printing body; in the direction from the bottom surface to the top surface of the three-dimensional printed object, the edges of the multiple layers of basic printing layers corresponding to the overhanging side wall that are away from the printing body are gradually increased layer by layer, and the edges of the multiple layers of outer wall color layers corresponding to the overhanging side wall that are away from the printing body are inclined layer by layer toward the side away from the printing body.

[0017] Among them, the three-dimensional printed object further includes multiple layers of fixed color layers, and the fixed color layers are arranged in a stacked manner with the outer wall color layers; the side of the fixed color layer close to the printing body protrudes from the side of the corresponding outer wall color layer close to the printing body; and the part of the fixed color layer close to the printing body and protruding from the corresponding outer wall color layer is inserted into the printing body to be arranged in contact with each adjacent two layers of basic printing layers.

[0018] Among them, the basic printing layer includes multiple layers of outer printing layers and inner printing layers; the thickness of the outer printing layer is less than the thickness of the inner printing layer.

[0019] Among them, the outer printing layer of the multiple layers of basic printing layers corresponding to the overhanging side wall is an outer wall transmissive printing layer, and the outer wall transmissive printing layer extends toward the side away from the printing body until it is exposed; a fixed color layer is inserted between every two adjacent outer wall transmissive printing layers.

[0020] Among them, the color layer further includes an end face color layer, and the three-dimensional printed object further includes an end face transmissive printing layer; the printing body includes at least one end face, and the end face color layer is arranged in contact with the end face; among them, the end face includes a bottom surface, a bridge bottom surface, and a top surface; among them, when the end face is the bottom surface or the bridge bottom surface, the end face transmissive printing layer is arranged in contact with the side of the end face color layer away from the printing body.

[0021] To solve the above technical problems, the three-dimensional printed object of the present application obtains the printing trajectory of the current outer wall color layer and the printing trajectory of the current basic printing layer; determines whether the edge of the current basic printing layer corresponds to protruding beyond the edge of the previous basic printing layer; if the edge of the current basic printing layer does not correspond to protruding beyond the edge of the previous basic printing layer, multiple layers of the current outer wall color layer are laminated and printed in the edge area of the printing surface of the object to be printed and the current basic printing layer is printed in the middle area of the printing surface to obtain an additive printing object; the additive printing object is used as a new object to be printed, and the steps of determining whether the edge of the current basic printing layer corresponds to protruding beyond the edge of the previous basic printing layer and subsequent steps are cyclically executed until a three-dimensional printed object is obtained. Since the thickness of the outer wall color layer is less than the thickness of the basic printing layer, the accuracy of the outer wall color layer is higher than that of the basic printing layer, and multiple layers of the outer wall color layer are laminated in the edge area, so that the shape accuracy of the outermost side of the three-dimensional printed object can be improved by using multiple layers of the outer wall color layer, and further the appearance accuracy of the three-dimensional printed object is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic flowchart of an embodiment of the printing method of the three-dimensional printed object provided by the present application;

[0023] Figure 2 is a schematic flowchart of another embodiment of the printing method of the three-dimensional printed object provided by the present application;

[0024] Figure 3 is a schematic cross-sectional structure diagram of an embodiment of the three-dimensional printed object provided by the present application;

[0025] Figure 4 is a schematic structural diagram of an implementation manner of the basic printing layer and the corresponding color layer;

[0026] Figure 5 is a schematic structural diagram of another implementation manner of the basic printing layer and the corresponding color layer;

[0027] Figure 6 is a schematic cross-sectional structure diagram of another embodiment of the three-dimensional printed object provided by the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0029] It should be noted that if there are directional indications (such as up, down, left, right, front, back...) involved in the embodiments of this application, then such directional indications are only used to explain the relative positional relationship, movement conditions, etc. between components in a certain specific posture (as shown in the drawings). If this specific posture changes, then the directional indications will also change accordingly.

[0030] In addition, if there are descriptions such as "first", "second", etc. involved in the embodiments of this application, then such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second" can explicitly or implicitly include at least one such feature. In addition, the technical solutions between various embodiments can be combined with each other, but it must be based on what can be achieved by those of ordinary skill in the art. When the combination of technical solutions results in contradictions or cannot be achieved, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0031] Please refer to Figure 1 , Figure 1 which is a schematic flowchart of an embodiment of the printing method for three-dimensional printed objects provided by this application.

[0032] Step S11: Obtain the printing trajectory of the current outer wall color layer and the printing trajectory of the current base printing layer.

[0033] The object to be printed refers to any intermediate product during the printing process of the three-dimensional printed object. The object to be printed in this embodiment is the one on which the base printing layer and the outer wall color layer still need to be printed.

[0034] In a specific application scenario, the printing trajectory of the current outer wall color layer and the printing trajectory of the current base printing layer can be determined by slicing and dividing based on the appearance of the three-dimensional printed object through experience. In a specific application scenario, the printing trajectory of the current outer wall color layer and the printing trajectory of the current base printing layer can also be determined by dividing based on the appearance of the three-dimensional printed object through the corresponding simulation software or the corresponding trained deep learning model. The specific acquisition method is not limited herein.

[0035] Step S12: Determine whether the edge of the current base printing layer protrudes corresponding to the edge of the previous base printing layer.

[0036] If the edge of the current base printing layer protrudes corresponding to the edge of the previous base printing layer, it indicates that the current base printing layer being printed at this time is a hanging structure. If the edge of the current base printing layer does not protrude corresponding to the edge of the previous base printing layer, it indicates that the current base printing layer being printed at this time is a flat structure or an inwardly inclined structure.

[0037] Step S13: If the edge of the current base printing layer does not protrude corresponding to the edge of the previous base printing layer, multiple layers of the current outer wall color layers are printed in a stacked manner in the edge area of the printing surface of the object to be printed, and the current base printing layer is printed in the middle area of the printing surface, so as to obtain a laminated printing object; wherein, the stacked thickness of the multiple layers of the current outer wall color layers is equal to the thickness of the current base printing layer, and the edge area is arranged to surround and fit the middle area.

[0038] If the edge of the current base printing layer does not protrude corresponding to the edge of the previous base printing layer, it indicates that the current base printing layer being printed at this time is a flat structure or an inwardly inclined structure. At this time, the printing of the outer wall color layer has a bottom layer for attachment, so multiple layers of the current outer wall color layers can be printed in a stacked manner directly in the edge area of the printing surface of the object to be printed, and the current base printing layer can be printed in the middle area of the printing surface, so as to obtain a laminated printing object. If the edge area is arranged to surround and fit the middle area, then the current outer wall color layer also surrounds and fits the current base printing layer.

[0039] In a specific application scenario, the current base printing layer can be printed by the fused deposition modeling (FDM) technology. In a specific application scenario, the current base printing layer can also be printed by printing technologies such as resin three-dimensional printing technology, powder bed fusion printing technology, material jet (M-Jet) printing technology, and plastic freeform (APF) printing technology, etc., which are not limited herein.

[0040] In a specific application scenario, the current color layer can be printed by full-color inkjet stereolithography three-dimensional printing technology. In a specific application scenario, the current color layer can also be printed by ink printing technologies such as thermosetting ink printing technology, curing agent ink printing technology, or other ink printing technologies cured by chemical methods.

[0041] Among them, since the stacked thickness of the multiple layers of the current outer wall color layers is equal to the thickness of the current base printing layer, it indicates that the thickness of the outer wall color layer is less than the thickness of the base printing layer, so that the accuracy and resolution of the outer wall color layer are higher than those of the base printing layer. By stacking multiple layers of the outer wall color layers, the shape accuracy of the outermost side of the three-dimensional printing object can be improved by using the multiple layers of the outer wall color layers arranged in the edge area, and thus the appearance accuracy of the three-dimensional printing object can be improved.

[0042] Step S14: Take the laminated printing object as the new object to be printed, and loop through the steps of judging whether the edge of the current base printing layer protrudes corresponding to the edge of the previous base printing layer and the subsequent steps until a three-dimensional printing object is printed.

[0043] In a specific application scenario, if after adding a base printing layer and multiple color layers on the object to be printed to obtain a printed object with added layers, printing still needs to continue, then the printed object with added layers is used as the new object to be printed, and the above steps S11 - S13 are cyclically executed until the addition of layers is completed to obtain a three-dimensional printed object.

[0044] In a specific application scenario, if after adding a base printing layer and multiple color layers on the object to be printed, the printing is completed, then the printed object with added layers is used as the three-dimensional printed object, and the printing ends.

[0045] Through the above steps, in this embodiment, the printing trajectories of the current outer wall color layer and the current base printing layer are obtained; it is determined whether the edge of the current base printing layer correspondingly protrudes beyond the edge of the previous base printing layer; if the edge of the current base printing layer does not correspondingly protrude beyond the edge of the previous base printing layer, multiple current outer wall color layers are layer-by-layer printed in the edge area of the printing surface of the object to be printed and the current base printing layer is printed in the middle area of the printing surface to obtain a printed object with added layers; the printed object with added layers is used as the new object to be printed, and the steps of determining whether the edge of the current base printing layer correspondingly protrudes beyond the edge of the previous base printing layer and subsequent steps are cyclically executed until a three-dimensional printed object is printed. Since the thickness of the outer wall color layer is less than the thickness of the base printing layer, the accuracy and resolution of the outer wall color layer are higher than those of the base printing layer, and multiple outer wall color layers are stacked in the edge area, so that the shape accuracy and color accuracy of the outermost side of the three-dimensional printed object can be improved by using multiple outer wall color layers, thereby improving the appearance accuracy and color accuracy of the three-dimensional printed object.

[0046] Please refer to Figure 2 , Figure 2 which is a schematic flowchart of another embodiment of the printing method of the three-dimensional printed object provided by this application.

[0047] Step S21: Obtain the printing trajectory of the bottom printing layer, and print the bottom printing layer based on the printing trajectory of the bottom printing layer; print the first end face color layer on the entire plate on one side of the bottom printing layer to obtain the object to be printed.

[0048] In this embodiment, the printing of the entire three-dimensional printed object is divided into layer-by-layer printing of a layer structure. That is, the three-dimensional printed object is obtained by stacking layer structures layer by layer. In a specific application scenario, if the printing of the entire three-dimensional printed object can be divided into a layer structure of 10 layers, then during printing, the layer structure of the first layer, the layer structure of the second layer, the layer structure of the third layer... the layer structure of the tenth layer are printed in sequence, and the three-dimensional printed object is obtained by stacking these 10 layer structures.

[0049] In this step, first obtain the overall shape of the three-dimensional printed object; slice the overall shape based on the thickness of the basic printing layer to obtain the printing trajectories of multiple layer structures of the three-dimensional printed object. Among them, the layer structure includes a single-layer basic printing layer and multiple color layers arranged on the same layer as it.

[0050] After obtaining the printing trajectories of multiple layer structures of the three-dimensional printed object, then shrink the printing trajectories of each layer structure by a preset distance to correspondingly obtain the printing trajectories of each basic printing layer, and correspondingly obtain the printing trajectories of each color layer based on the shrunk preset distance. That is, divide the printing trajectories of the layer structure into the printing trajectories of the basic printing layer and the printing trajectories of the color layer based on the preset distance.

[0051] Among them, the range of the preset distance can include 0.2 - 0.5 millimeters, specifically including 0.2 millimeters, 0.3 millimeters, 0.4 millimeters, or 0.5 millimeters, etc.

[0052] In a specific application scenario, assume that the three-dimensional printed object is a cylinder with a diameter of 5 millimeters. Then the printing trajectory of a certain layer structure is a circle with a diameter of 5 millimeters. If the preset distance is 0.3 millimeters, then the printing trajectory of the basic printing layer of this layer structure is a circle with a diameter of 4.7 millimeters, and the printing trajectories of the corresponding multiple color layers are rings with a ring width of 0.3 millimeters. This application scenario is only for illustration and not for shape limitation.

[0053] Among them, when shrinking the printing trajectories of each layer structure by the preset distance in this embodiment, all the exposed sides of the three-dimensional printed object on this layer structure are shrunk by the preset distance. That is, the outer surface of this layer structure will shrink. If there is a hollow structure, the outer surface of the hollow structure will also shrink by the preset distance. For example: if the three-dimensional printed object is a toroid with a ring width of 5 millimeters, then both the inner and outer sides of the toroid are shrunk by 0.3 millimeters to obtain the printing trajectory of the basic printing layer with a ring width of 4.4 millimeters, and the printing trajectories of two color layers with a ring width of 0.3 millimeters.

[0054] The slicing process can be carried out by slicing software. If the basic printing layer is printed using the FDM (Fused Deposition Modeling) fused deposition modeling technology, then the FDM slicing algorithm can be specifically adopted to slice the overall shape of the three-dimensional printed object to obtain the printing trajectories of the layer structure. When the printing technology of the basic printing layer is other printing technologies, the slicing process can also be correspondingly processed using the appropriate slicing software or model.

[0055] In this step, when starting to print the three-dimensional printed object, first print the bottom printing layer for priming, then obtain the printing trajectory of the bottom printing layer, print the bottom printing layer based on the printing trajectory of the bottom printing layer, and then set the first end face color layer on the side of the bottom printing layer close to the printing main body.

[0056] Since the bottom surface of the three-dimensional printed object also needs to display colors, but the bottom surface often needs to come into contact with other objects, directly setting a color layer may easily cause color peeling. Therefore, in this embodiment, a bottom surface printing layer is first set, and then a first end face color layer is set on the entire plate on the bottom surface printing layer, so as to protect the first end face color layer through the bottom surface printing layer and improve the structural stability of the first end face color layer.

[0057] In a specific application scenario, in order to facilitate the color transmission of the first end face color layer, the bottom surface printing layer can be set as a transmissive printing layer, so that the first end face color layer on the bottom surface is transmitted and displayed through the transmissive printing layer. At this time, covering the outside of the first end face color layer through the bottom surface printing layer can prevent the first end face color layer from being exposed, thereby improving the structural stability of the first end face color layer.

[0058] To ensure the transparency of the bottom surface printing layer, the thickness of the bottom surface printing layer can be less than the thickness of the base printing layer. Specifically, first print a thin and transparent bottom surface printing layer, then adjust the line width of the nozzle, turn on the ironing mode, and gently move on the printing surface in a way that does not extrude or extrudes less material, melting and flattening small particles and irregularities on the surface through heat and pressure. This process can reduce or eliminate the layer-like texture generated during printing, thereby obtaining a smoother surface effect. The purpose of ironing is to improve the smoothness and appearance of the printing surface. Subsequently, print the first end face color layer on the entire plate on the bottom surface printing layer. At this time, the first end face color layer can be not cured first, but after printing the first layer of the base printing layer on the first end face color layer, then perform light curing treatment through the base printing layer, so that both color saturation transmission can be ensured and the interlayer bonding force between the bottom surface printing layer and the base printing layer can be ensured.

[0059] Step S22: Determine whether the edge of the current base printing layer correspondingly protrudes beyond the edge of the previous base printing layer.

[0060] The side wall of the three-dimensional printed object includes one or more of a vertical side wall, an inner inclined side wall, and an overhanging side wall. When the current base printing layer protrudes beyond the previous base printing layer, it means that the overhanging side wall is being printed at this time. When the current base printing layer protrudes beyond the previous base printing layer, it means that the vertical side wall or the inner inclined side wall is being printed at this time.

[0061] Step S23: If the edge of the current base printing layer does not correspondingly protrude beyond the edge of the previous base printing layer, stack and print multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed and print the current base printing layer in the middle area of the printing surface to obtain an additive printed object.

[0062] If the edge of the current base printing layer does not protrude corresponding to the edge of the previous base printing layer, it indicates that the vertical side wall or the inner inclined side wall is being printed. At this time, since there is a bottom attachment for the stacked printing of the color layers, at least two of the following printing methods can be adopted for printing the layer structure:

[0063] The first printing method for the vertical side wall or the inner inclined side wall is: stack and print multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed until the cumulative thickness of the multiple stacked current outer wall color layers reaches one-half of the thickness of the current base printing layer; print the current base printing layer in the middle area of the printing surface of the object to be printed; stack and print the current outer wall color layer again on the side of the printed current outer wall color layer away from the printing surface until the cumulative thickness of the multiple stacked current outer wall color layers reaches the thickness of the current base printing layer, so as to obtain a layer-by-layer printed object.

[0064] Among them, the side of the multiple stacked current outer wall color layers close to the current base printing layer is arranged in a fitting manner with the current base printing layer.

[0065] Since the prepared shape of the current base printing layer may sometimes be arc-shaped, the printing trajectory of the outer wall color layer can be adjusted correspondingly according to the radian of the base printing layer to make it extend to a certain extent, so that the base printing layer is arranged in a fitting manner with the corresponding multiple layers of the outer wall color layer of the same layer. By printing the outer wall color layer in batches, the printing of the outer wall color layer and the printing of the base printing layer do not interfere with each other and do not block each other, and the fitting arrangement of the two is realized.

[0066] The second printing method for the vertical side wall or the inner inclined side wall is: stack and print multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed until the cumulative thickness of the multiple stacked current outer wall color layers reaches the thickness of the current base printing layer; in the middle area of the printing surface of the object to be printed, print the current base printing layer by fitting with the multiple layers of the current outer wall color layer to obtain a layer-by-layer printed object; among them, the side of the multiple stacked current outer wall color layers close to the current base printing layer is arranged flush. Thus, the printing of the multiple layers of the outer wall color layer arranged in the same layer as the current base printing layer is completed coherently, and the printing efficiency of the outer wall color layer is improved.

[0067] In a specific application scenario, after obtaining the incrementally printed object, a current fixed color layer is printed on the edge area of the current outer wall color layer on the side of the incrementally printed object away from the printing surface; wherein, the side of the current fixed color layer close to the middle area protrudes from the side of the current outer wall color layer close to the middle area, so that the current fixed color layer is arranged in a fitting manner with the side of the current basic printing layer away from the printing surface. The fixed color layer is arranged in a fitting manner with the current basic printing layer, thereby increasing the friction area between the two, further increasing the bonding force between the fixed color layer and the current basic printing layer, and further improving the bonding force between the entire color layer and the basic printing layer. The fixed color layer and the outer wall color layer are laminated and arranged in a fitting manner, and the materials are the same. Therefore, by increasing the bonding force between the fixed color layer and the basic printing layer, the bonding force between the entire color layer and the basic printing layer can be improved.

[0068] Step S24: If the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer, the current outer wall transmissive printing layer and the current fixed color layer are alternately laminated and printed in sequence on the edge area of the printing surface of the object to be printed; and the current basic printing layer is printed in the middle area of the printing surface of the object to be printed to obtain the incrementally printed object.

[0069] If the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer, it indicates that the overhanging side wall is being printed at this time. Since there is no bottom attachment for the lamination printing of the color layer at this time, the following method can be adopted for printing: the current outer wall transmissive printing layer and the current fixed color layer are alternately laminated and printed in sequence on the edge area of the printing surface of the object to be printed; and the current basic printing layer is printed in the middle area of the printing surface of the object to be printed to obtain the incrementally printed object.

[0070] Among them, by setting the edge area of the basic printing layer corresponding to the overhanging side wall as the transmissive printing layer, the appearance shape of the three-dimensional printed object in this part is presented. By inserting a fixed color layer between adjacent outer wall transmissive printing layers and combining the transmissive properties of the outer wall transmissive printing layer, the color of the fixed color layer is transmitted, thereby ensuring the appearance color of the three-dimensional printed object in this part.

[0071] In a specific application scenario, the thickness of the outer wall transmissive printing layer can be less than the thickness of the basic printing layer, which can increase the accuracy and resolution of the transmissive printing layer, and further improve the surface accuracy of the three-dimensional printed object.

[0072] Through the above printing method, the vertical side wall, inner inclined side wall and overhanging side wall of the three-dimensional printed object can be printed, so as to combine three-dimensional printed objects with arbitrary appearance shapes. Moreover, the different printing methods adopted for different side walls in this embodiment can improve the printing success rate of different side walls.

[0073] Step S25: Take the incrementally printed object as the new object to be printed, and loop through the steps of determining whether the edge of the current base printing layer protrudes corresponding to the edge of the previous base printing layer and subsequent steps until the increment is completed.

[0074] In a specific application scenario, if, after incrementing a base printing layer and a color layer on the object to be printed, printing still needs to continue, then take the incrementally printed object as the new object to be printed, and loop through the above steps S22 - S24 until the increment is completed to obtain the final incrementally printed object.

[0075] In a specific application scenario, if, after incrementing a base printing layer and a color layer on the object to be printed, printing has been completed, then step S25 will be executed.

[0076] Step S26: On the side of the incrementally printed object away from the bottom printing layer, integrally print the second end - face color layer to obtain a three - dimensional printed object.

[0077] In a specific application scenario, when the three - dimensional printed object needs to print the top end - face, then finally the top printing layer needs to be printed. Also, integrally print the second end - face color layer on the side of the final incrementally printed object away from the bottom printing layer to cover the appearance color of this end - face. If necessary, the printing trajectory of the top printing layer can also be obtained, and based on the printing trajectory of the top printing layer, print the top printing layer on the side of the second end - face color layer away from the incrementally printed object.

[0078] Among them, after printing the second end - face color layer, it can be not cured first. Directly print the top printing layer on the second end - face color layer, reduce the nozzle line width, and turn on the ironing mode to ensure that the top printing layer is flat and delicate. Then, through the top printing layer, perform light curing on the second end - face color layer, thereby improving the inter - layer bonding force between the top printing layer and the incrementally printed object.

[0079] Both the top printing layer and the bottom printing layer in this embodiment are transmissive printing layers. That is, in order to facilitate the color of the top color layer to be transmitted, the top printing layer can be set as a transmissive printing layer so that the second end - face color layer on the top is displayed through the color transmitted by the transparent top printing layer. At this time, by covering the outside of the end - face color layer with the top printing layer, it can prevent the second end - face color layer from being exposed, thereby improving the structural stability of the second end - face color layer.

[0080] In some embodiments, specifically, the fused deposition modeling technology can be used to layer-print the basic printing layer; and the color layer can be layer-printed using photocurable ink. That is, the multiple basic printing layers of the printing body can be printed layer by layer through the fused deposition modeling technology (FDM, Fused Deposition Modeling), thereby improving the printing efficiency of the printing body. The color layer of the color shell can be printed layer by layer through the full-color inkjet photocuring 3D printing technology, thereby improving the accuracy and color fineness of the color layer. Full-color inkjet photocuring 3D printing sprays photocurable ink with a traditional inkjet nozzle, then irradiates it with ultraviolet light to cure the ink, and then sprays photocurable ink on the cured layer according to the printing trajectory, and then cures it again, layer by layer printing until the model printing is completed. Among them, the photocurable ink can include cyan ink, magenta ink, yellow ink, black ink, white ink, transparent ink, white or transparent ink, to adapt to various color requirements. In this embodiment, the printing body of the three-dimensional printed object prepared by the fused deposition modeling technology can use FDM wire instead of relatively expensive photosensitive ink or white ink material, thereby reducing the cost of the three-dimensional printed object.

[0081] Through the above steps, the printing method of the three-dimensional printed object in this embodiment obtains the printing trajectories of each basic printing layer and the printing trajectories of each outer wall color layer by shrinking the printing trajectories of the multiple layer structures of the three-dimensional printed object by a preset distance, and then prints the basic printing layer and the outer wall color layer, so as to improve the shape accuracy of the outermost side of the three-dimensional printed object by using a more delicate color layer, and further improve the appearance accuracy of the three-dimensional printed object. And use the color layer with high precision to express a more delicate and more realistic color performance, improving the color presentation accuracy and color restoration of the three-dimensional printed object. And in this embodiment, a fixed color layer is inserted between every two adjacent basic printing layers to increase the bonding force between the fixed color layer and the basic printing layer, improve the bonding force between the entire color layer and the basic printing layer, and improve the structural stability and reliability of the three-dimensional printed object. And in this embodiment, the edge area of the basic printing layer corresponding to the overhanging side wall is set as a transmissive printing layer to present the appearance shape of the three-dimensional printed object in this part. And by inserting a fixed color layer between adjacent transmissive printing layers and combining the transmissive properties of the transmissive printing layer, the color of the fixed color layer is transmitted, thereby ensuring the appearance color of the three-dimensional printed object in this part. In addition, to ensure the end face color of the three-dimensional printed object, an end face color layer is set at the end face, the end face color layer covers the entire end face, and a transmissive printing layer is set on the side of the end face color layer away from the basic printing layer, so that the color of the end face is transmitted and displayed through the transmissive printing layer. And at this time, by covering the outside of the end face color layer with the transmissive printing layer, it is possible to prevent the end face color layer from being exposed, thereby improving the structural stability of the end face color layer.

[0082] Please refer toFigure 3 , Figure 3 It is a schematic cross-sectional structure diagram of an embodiment of a three-dimensional printed object provided by the present application. The three-dimensional printed object of this embodiment is prepared by the printing method of the three-dimensional printed object of any of the above embodiments.

[0083] The three-dimensional printed object 100 of this embodiment includes a printing main body 110 and a color shell 120. The printing main body 110 is the main printing structure of the three-dimensional printed object 100, and its shape can be specifically designed based on the actual requirements of the three-dimensional printed object 100, including but not limited to: cube, cylinder, cone, frustum, humanoid three-dimensional structure, animal body three-dimensional structure or irregular three-dimensional structure, etc., for supporting the appearance shape of the three-dimensional printed object 100. The color shell 120 is the outermost color structure of the three-dimensional printed object 100, for reflecting the appearance color of the three-dimensional printed object 100. And the color shell 120 is arranged on the outside of the three-dimensional printed object 100, and can also smooth the appearance of the three-dimensional printed object 100.

[0084] The printing main body 110 includes multiple layers of basic printing layers 111 that are stacked and attached. That is, in this embodiment, the printing main body 110 is formed by stacking multiple layers of basic printing layers 111. The color shell 120 is arranged to wrap the exposed side of the printing main body 110, so that the outermost appearance shape and color of the three-dimensional printed object 100 are directly presented by the color shell 120.

[0085] The color shell 120 includes multiple layers of outer wall color layers 121 that are stacked and attached. The outer wall color layers 121 and the basic printing layers 111 are stacked relative to the same horizontal plane, and the thickness of the outer wall color layers 121 is less than the thickness of the basic printing layers 111.

[0086] Since the thickness of the outer wall color layers 121 is less than the thickness of the basic printing layers 111, the accuracy and resolution of the outer wall color layers 121 are higher than those of the basic printing layers 111. By stacking multiple layers of outer wall color layers 121 and wrapping the exposed side of the printing main body 110, the shape accuracy of the outermost side of the three-dimensional printed object 100 can be improved by using the multiple layers of outer wall color layers 121, and further the appearance accuracy of the three-dimensional printed object 100 can be improved.

[0087] And in this embodiment, by separately arranging the multiple layers of outer wall color layers 121 on the exposed side of the three-dimensional printed object 100, the outer wall color layers 121 with high accuracy can also be used to express a more delicate and more realistic color performance, thereby improving the color presentation accuracy and color reduction degree of the three-dimensional printed object 100.

[0088] Through the above steps, the three-dimensional printed object of this embodiment is provided with a printing body including multiple stacked and fitted basic printing layers and a color shell including multiple stacked and fitted color layers. Among them, the color shell is arranged to wrap the exposed side of the printing body. The color layers and the basic printing layers are stacked with respect to the same horizontal plane, and the thickness of the color layers is less than the thickness of the basic printing layers, so as to improve the shape accuracy of the outermost side of the three-dimensional printed object by using the finer and higher-resolution color layers, thereby improving the appearance accuracy of the three-dimensional printed object. And use the high-precision color layers to express more delicate and realistic color performance, improving the color presentation accuracy and color restoration of the three-dimensional printed object.

[0089] In some embodiments, the multiple basic printing layers 111 of the printing body 110 can be printed layer by layer through the fused deposition modeling (FDM) technology, so as to improve the printing efficiency of the printing body 110. And the outer wall color layer 121 of the color shell 120 can be printed layer by layer through the full-color inkjet stereolithography 3D printing technology, so as to improve the accuracy and color fineness of the outer wall color layer 121. The full-color inkjet stereolithography 3D printing is to eject the photocurable ink with a traditional inkjet print head, and then irradiate it with ultraviolet light to cure the ink. Then, the photocurable ink is sprayed on the cured layer according to the printing track, and then cured, and printed layer by layer until the model printing is completed. Among them, the photocurable ink can include cyan ink, magenta ink, yellow ink, black ink, white ink, transparent ink, white or transparent ink, to adapt to various color requirements.

[0090] In some embodiments, the multiple basic printing layers 111 of the printing body 110 can also be printed through high-efficiency printing technologies such as resin 3D printing technology, powder bed fusion printing technology, material jetting (M-Jet) printing technology, and additive plastic fabrication (APF) printing technology. And the outer wall color layer 121 of the color shell 120 can also be printed through high-precision ink printing technologies such as thermosetting ink printing technology and curing agent ink printing technology, which are not specifically limited here.

[0091] In some embodiments, the multiple outer wall color layers 121 arranged on the same layer as the basic printing layer 111 are all fitted with the basic printing layer 111; among them, the outer wall color layer 121 is fitted with the basic printing layer 111, which can improve the tight bonding force between the outer wall color layer 121 and the basic printing layer 111, and improve the structural stability between the color shell 120 and the printing body 110.

[0092] In a specific application scenario, the prepared shape of the base printing layer 111 may sometimes be arc-shaped. In this case, the printing trajectory of the outer wall color layer 121 can be adjusted according to the radian of the base printing layer 111 to make it extend to a certain extent, so that the base printing layer 111 and the corresponding multi-layer outer wall color layer 121 of the same layer are arranged in a fitting manner, thereby improving the tight bonding force between the outer wall color layer 121 and the base printing layer 111. In other application scenarios, the prepared shape of the base printing layer 111 can also be inclined, concave, vertical, etc., which is specifically determined based on the actual preparation situation and will not be limited here.

[0093] Please refer to Figure 4 , Figure 4 which is a schematic structural diagram of an embodiment of the base printing layer and the corresponding color layer.

[0094] In this embodiment, the base printing layer 111 and the outer wall color layer 121 arranged in the same layer are all arranged in a fitting manner, that is, the multi-layer color layers are adjusted and extended slightly along the radian of the base printing layer 111 to be arranged in a fitting manner, thereby improving the tight bonding force between the outer wall color layer 121 and the base printing layer 111.

[0095] In some embodiments, the multi-layer outer wall color layers 121 arranged in the same layer as the base printing layer 111 are arranged flush on the side close to the base printing layer 111. The multi-layer outer wall color layers 121 arranged flush can be printed continuously without considering the printing situation of the base printing layer 111 arranged in the same layer, thereby improving the printing efficiency of the color shell 120.

[0096] Please refer to Figure 5 , Figure 5 which is a schematic structural diagram of another embodiment of the base printing layer and the corresponding color layer.

[0097] In this embodiment, the base printing layer 111 is arranged flush with the outer wall color layer 121 arranged in the same layer. The multi-layer outer wall color layers 121 arranged flush can be printed continuously without considering the printing situation of the base printing layer 111 arranged in the same layer, thereby improving the printing efficiency of the color shell 120.

[0098] Please refer to Figure 6 , Figure 6 which is a schematic cross-sectional structural diagram of another embodiment of the three-dimensional printed object provided by the present application.

[0099] The covering relationship and printing method between the printing main body 210 and the color shell 220 in this embodiment are the same as those in the foregoing embodiments. For this part, please refer to the previous text and will not be elaborated here.

[0100] In some embodiments, the three-dimensional printed object 200 includes one or more of a vertical sidewall 231, an inwardly inclined sidewall 233, and an overhanging sidewall 232. Among them, the vertical sidewall 231 is a part of the printing body 210 having a vertical side surface. The inwardly inclined sidewall 233 is a part of the printing body 210 having a side surface that gradually inclines inward. The overhanging sidewall 232 is a part of the printing body 210 having a side surface that gradually inclines outward. In practical applications, various parts of the three-dimensional printed object 200 can be roughly divided into the above three parts. For the convenience of illustration, in this embodiment, the printing body 210 is taken as an example including a vertical sidewall 231, an inwardly inclined sidewall 233, and an overhanging sidewall 232 for description. However, in practical applications, the specific sidewall shape of the three-dimensional printed object 200 can be set arbitrarily and is not limited herein.

[0101] Specifically, the sides of the multiple layers of the base printing layer 211 corresponding to the vertical sidewall 231 that are away from the printing body 210 are arranged flush to form a vertical sidewall, and the sides of the multiple layers of the color layer 221 corresponding to the vertical sidewall 231 that are away from the printing body 210 are arranged flush to ensure the appearance shape of the three-dimensional printed object 200.

[0102] In the direction from the bottom surface 241 to the top surface 242 of the three-dimensional printed object 200, the edges of the multiple layers of the base printing layer 211 corresponding to the inwardly inclined sidewall 233 that are away from the printing body 210 are gradually shortened layer by layer, and the edges of the multiple layers of the color layer 221 corresponding to the inwardly inclined sidewall 233 that are away from the printing body 210 are inclined layer by layer toward the side closer to the printing body 210.

[0103] In the direction from the bottom surface 241 to the top surface 242 of the three-dimensional printed object 200, the edges of the multiple layers of the base printing layer 211 corresponding to the overhanging sidewall 232 that are away from the printing body 210 are gradually increased layer by layer, and the edges of the multiple layers of the color layer 221 corresponding to the overhanging sidewall 232 that are away from the printing body 210 are inclined layer by layer toward the side away from the printing body 210.

[0104] By assembling and combining the vertical sidewall 231, the inwardly inclined sidewall 233, and the overhanging sidewall 232, a three-dimensional printed object 200 with various sidewall shapes can be formed. Among them, for the convenience of illustration, the sidewall structures of the three-dimensional printed object 200 on the same horizontal plane in this embodiment are the same. However, in actual situations, the sidewall structures on the same horizontal plane can be set arbitrarily based on actual needs and are not limited herein.

[0105] In some embodiments, the color layer 221 corresponding to the vertical sidewall 231 and the color layer 221 corresponding to the inwardly inclined sidewall 233 both include a fixed color layer 223 and an outer wall color layer 222, and the fixed color layer 223 and the outer wall color layer 222 are stacked. The side of the fixed color layer 223 close to the printing body 210 protrudes from the side of the corresponding outer wall color layer 222 close to the printing body 210.

[0106] Wherein, a portion of the fixed color layer 223 that is close to the printing main body 210 and protrudes from the corresponding outer wall color layer 222 is inserted into the printing main body 210, so that a fixed color layer 223 is inserted between every two adjacent basic printing layers 211, that is, the fixed color layer 223 is arranged in contact with two adjacent basic printing layers 211.

[0107] By inserting the fixed color layer 223 between two adjacent basic printing layers 211, the friction area between the fixed color layer 223 and the basic printing layer 211 can be increased, thereby increasing the bonding force between the fixed color layer 223 and the basic printing layer 211. The fixed color layer 223 and the outer wall color layer 222 are stacked and arranged in contact with each other and have the same material. Therefore, by increasing the bonding force between the fixed color layer 223 and the basic printing layer 211, the bonding force between the entire color shell 220 and the basic printing layer 211 can be improved, and the structural stability and reliability between the color shell 220 and the printing main body 210 can be improved.

[0108] In a specific application scenario, the range of the preset distance between the outermost track and the corresponding innermost track of the outer wall color layer 222 can be determined based on experimental measurement of the color reduction effect, specifically, it can be 0.2 - 0.5 mm, specifically, it can be 0.2 mm, 0.3 mm, 0.4 mm or 0.5 mm, etc. The outer wall color layer 222 within this distance range can not only provide sufficient color reduction, but also avoid excessive distance from increasing printing consumption. The distance range between the outermost track and the corresponding innermost track of the fixed color layer 223 can be 0.6 - 1.5 mm, specifically, it can be 0.6 mm, 0.8 mm, 1.0 mm, 1.1 mm, 1.2 mm or 1.5 mm, etc. The fixed color layer 223 within this distance range can not only provide sufficient interlayer bonding force between the color shell 220 and the basic printing layer 211, but also prevent affecting the bonding force between adjacent basic printing layers 211.

[0109] In some embodiments, the basic printing layer 211 includes multiple outer printing layers 212 and an inner printing layer 213; the thickness of the outer printing layer 212 is less than the thickness of the inner printing layer 213.

[0110] By making the thickness of the outer printing layer 212 less than the thickness of the inner printing layer 213, the precision and resolution of the outer printing layer 212 can be increased, thereby improving the surface precision of the printing main body 210 and the three-dimensional printed object 200.

[0111] In a specific application scenario, the outer printing layer 212 of the same layer may include two circles of outer printing layers 212, where the inner circle of the outer printing layer 212 is used to connect the outer printing layer 212 of the outer circle and the inner printing layer 213, so as to improve the bonding force between the two, and further improve the structural stability and reliability of the printing body 210.

[0112] In some embodiments, the thickness of the outer printing layer 212 may also be equal to the thickness of the inner printing layer 213, so as to ensure the printing efficiency of the basic printing layer 211 to a certain extent.

[0113] In some embodiments, the outer printing layer 212 of the multi-layer basic printing layer 211 corresponding to the overhanging side wall 232 is an outer wall transmissive printing layer 215; the color layer 221 corresponding to the overhanging side wall 232 includes a fixed color layer 223; the outer wall transmissive printing layer 215 extends away from the printing body 210 until it passes through the fixed color layer 223 for exposure; a fixed color layer 223 is inserted between every two adjacent outer wall transmissive printing layers 215.

[0114] Since the overhanging side wall 232 is inclined outwards, the stacked printing of the color layer 221 has no bottom attachment. Therefore, in this embodiment, the outer printing layer 212 of the basic printing layer 211 corresponding to the overhanging side wall 232 is set as the outer wall transmissive printing layer 215 and extended to the outside for exposure, so as to present the appearance shape of the three-dimensional printed object 200 in this part. By inserting the fixed color layer 223 between adjacent outer wall transmissive printing layers 215 and combining the transparent property of the outer wall transmissive printing layer 215, the color of the fixed color layer 223 is transmitted, thereby ensuring the appearance color of the three-dimensional printed object 200 in this part.

[0115] In a specific application scenario, the thickness of the outer wall transmissive printing layer 215 may be smaller than the thickness of the outer printing layer 212 corresponding to the vertical side wall 231 or the inner inclined side wall 233, so as to improve the appearance shape accuracy and resolution of the overhanging side wall 232 through multiple outer wall transmissive printing layers 215 with small thickness. Among them, the thickness range of the outer wall transmissive printing layer 215 may be less than 0.05 mm, specifically 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm or 0.05 mm, etc. The thickness range of the outer printing layer 212 corresponding to the vertical side wall 231 or the inner inclined side wall 233 may be 0.15 - 0.25 mm, specifically 0.15 mm, 0.08 mm, 0.20 mm, 0.23 mm or 0.25 mm, etc. The transparency range of the outer wall transmissive printing layer 215 may be above 70%, specifically 70%, 75%, 80%, 85%, 90% or 95%, etc., so as to transmit the color of the fixed color layer 223 and ensure the appearance color of the three-dimensional printed object 200 in this part.

[0116] In some embodiments, the color layer 221 further includes an end face color layer 221, and the three-dimensional printed object 200 further includes an end face transmissive printing layer 214; the printing body 210 includes at least one end face (not labeled in the figure), the end face color layer 221 is disposed in conformity with the entire end face, and the end face transmissive printing layer 214 is disposed in conformity with a side of the end face color layer 221 away from the printing body 210; wherein, the end face may include a bottom face 241, a bottom face of a bridge (not shown in the figure), and a top face 242. The end face transmissive printing layer 214 includes a bottom face printing layer and a top face printing layer.

[0117] The three-dimensional printed object 200 is provided with a bottom face 241, and may also be provided with a top face 242. For example, when the three-dimensional printed object 200 is a pyramid, it has only one bottom face 241 and no top face 242. When the three-dimensional printed object 200 is a cylinder, it has both a bottom face 241 and a top face 242. The bottom face 241 and / or the top face 242 of the same three-dimensional printed object 200 may be one or more. For example: when the three-dimensional printed object 200 is a cylinder, its bottom face 241 is one, and its top face 242 is also one. When the three-dimensional printed object 200 is a four-corner table, it may include four table corners and a tabletop, a total of 5 bottom faces of bridges. When the three-dimensional printed object 200 is a fence, it may include multiple bottom faces of bridges and multiple top faces 242. And so on, which are not limited herein.

[0118] Wherein, in order to ensure the color display and structural stability of the bottom face 241 and the top face 242, in this embodiment, an end face color layer 221 is provided at the bottom face 241 and the top face 242, the end face color layer 221 covers the entire end face, and then an end face transmissive printing layer 214 is provided on a side of the end face color layer 221 away from the printing body 210, so that the colors of the bottom face 241 and the top face 242 are displayed through the color of the end face color layer 221 transmitted by the end face transmissive printing layer 214. At this time, by covering the end face transmissive printing layer 214 outside the end face color layer 221, the exposure of the end face color layer 221 can be prevented, thereby improving the structural stability of the end face color layer 221.

[0119] Wherein, the transparency of the end face transmissive printing layer 214 may be the same as the transparency of the outer wall transmissive printing layer 215. To ensure the transparency, the thickness of the end face transmissive printing layer 214 is less than the thickness of the base printing layer 211, and may be the same as the thickness of the outer wall transmissive printing layer 215.

[0120] In a specific application scenario, the top face 242 may also be provided with only the end face color layer 221 to ensure the appearance color, without providing the end face transmissive printing layer 214.

[0121] With the above structure, the three-dimensional printed object of this embodiment improves the shape accuracy of the outermost side of the three-dimensional printed object by setting a color shell on the exposed side of the printing body, increases the resolution of the outer wall color layer, and further improves the appearance accuracy of the three-dimensional printed object. Moreover, the highly accurate outer wall color layer is used to express a more delicate and realistic color performance, improving the color presentation accuracy and color restoration of the three-dimensional printed object. In this embodiment, a fixed color layer is inserted between every two adjacent basic printing layers to increase the bonding force between the fixed color layer and the basic printing layer, improve the bonding force between the entire color shell and the basic printing layer, and enhance the structural stability and reliability between the color shell and the printing body. The outer printing layer of the multi-layer basic printing layers corresponding to the overhanging sidewall is set as an outer wall transmissive printing layer and extended to the outside for exposure to present the appearance shape of the three-dimensional printed object in this part. A fixed color layer is inserted between every two adjacent outer wall transmissive printing layers to transmit the color of the fixed color layer in combination with the transparent property of the outer wall transmissive printing layer, thereby ensuring the appearance color of the three-dimensional printed object in this part. In addition, to ensure the end face color of the three-dimensional printed object, an end face color layer is set at the end face. The end face color layer covers the entire end face, and an end face transmissive printing layer is set on the side of the end face color layer away from the printing body, so that the color of the end face is displayed through the color of the end face color layer transmitted by the end face transmissive printing layer. At this time, by covering the outer side of the end face color layer with the end face transmissive printing layer, the exposure of the end face color layer can be prevented, and the structural stability of the end face color layer can be further improved.

[0122] The above are only the implementation manners of this application, and do not limit the patent scope of this application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of this application, or directly or indirectly applied in other related technical fields, shall be similarly included in the patent protection scope of this application.

Claims

1. A printing method for a three-dimensional printed object, characterized in that, The printing method of the three-dimensional printed object includes: Obtaining the printing trajectory of the current outer wall color layer and the printing trajectory of the current base printing layer; Judging whether the edge of the current base printing layer correspondingly protrudes from the edge of the previous base printing layer; If the edge of the current base printing layer does not correspondingly protrude from the edge of the previous base printing layer, layer-by-layer printing is respectively performed in the edge area of the printing surface of the object to be printed to obtain multiple layers of the current outer wall color layer and the current base printing layer is printed in the middle area of the printing surface to obtain a laminated printing object; wherein, the laminated thickness of the multiple layers of the current outer wall color layer is equal to the thickness of the current base printing layer, and the edge area is arranged to fit around the middle area; Taking the laminated printing object as a new object to be printed, and looping through the steps of judging whether the edge of the current base printing layer correspondingly protrudes from the edge of the previous base printing layer and subsequent steps until a three-dimensional printed object is printed.

2. The printing method of a three-dimensional printed object according to claim 1, characterized in that, The step of respectively layer-by-layer printing multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed and printing the current base printing layer in the middle area of the printing surface to obtain a laminated printing object includes: Layer-by-layer printing multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed until the cumulative thickness of the multiple layers of the laminated current outer wall color layer reaches one-half of the thickness of the current base printing layer; Printing the current base printing layer in the middle area of the printing surface of the object to be printed; Performing layer-by-layer printing of the current outer wall color layer again on the side of the already printed current outer wall color layer away from the printing surface until the cumulative thickness of the multiple layers of the laminated current outer wall color layer reaches the thickness of the current base printing layer to obtain the laminated printing object; Wherein, the side of the multiple layers of the laminated current outer wall color layer close to the current base printing layer is all arranged to fit with the current base printing layer.

3. The printing method of a three-dimensional printed object according to claim 1, characterized in that The step of respectively layer-by-layer printing multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed and printing the current base printing layer in the middle area of the printing surface to obtain a laminated printing object includes: Layer-by-layer printing multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed until the cumulative thickness of the multiple layers of the laminated current outer wall color layer reaches the thickness of the current base printing layer; Printing the current base printing layer by fitting multiple layers of the current outer wall color layer in the middle area of the printing surface of the object to be printed to obtain the laminated printing object; Wherein, the side of the multiple layers of the laminated current outer wall color layer close to the current base printing layer is arranged flush.

4. The printing method of the three-dimensional printed object according to any one of claims 1-3, characterized in that, The step of respectively layer-by-layer printing multiple layers of the current outer wall color layer in the edge area of the printing surface of the object to be printed and printing the current base printing layer in the middle area of the printing surface to obtain a laminated printing object further includes: Print a current fixed color layer on the edge area of the current outer wall color layer on the side of the incremental printing object away from the printing surface; wherein, one side of the current fixed color layer close to the middle area protrudes from one side of the current outer wall color layer close to the middle area, so that the current fixed color layer is arranged in a fitting manner with the side of the current basic printing layer away from the printing surface.

5. The printing method of the three-dimensional printed object according to claim 4, characterized in that, The step of determining whether the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer further includes: If the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer, alternately stack and print the current outer wall transmissive printing layer and the current fixed color layer in sequence in the edge area of the printing surface of the object to be printed; and print the current basic printing layer in the middle area of the printing surface of the object to be printed to obtain an incremental printing object.

6. The printing method of the three-dimensional printed object according to claim 1, characterized in that, Before the step of determining whether the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer, it further includes: Obtain the printing trajectory of the bottom printing layer, and print the bottom printing layer based on the printing trajectory of the bottom printing layer; Print the first end face color layer on the whole plate on one side of the bottom printing layer to obtain the object to be printed.

7. The printing method of the three-dimensional printed object according to claim 6, characterized in that, The step of taking the incremental printing object as a new object to be printed, and circularly executing the step of determining whether the edge of the current basic printing layer correspondingly protrudes from the edge of the previous basic printing layer and subsequent steps until a three-dimensional printing object is printed further includes: Print the second end face color layer on the whole plate on the side of the incremental printing object away from the bottom printing layer to obtain a three-dimensional printing object.

8. The printing method of the three-dimensional printed object according to claim 1, characterized in that The step of obtaining the printing trajectory of the current outer wall color layer and the printing trajectory of the current basic printing layer includes: Obtain the overall shape of the three-dimensional printing object; Perform slicing processing on the overall shape based on the thickness of the basic printing layer to obtain the printing trajectories of multiple layer structures of the three-dimensional printing object; Shrink the printing trajectories of each layer structure by a preset distance to correspondingly obtain the printing trajectories of each basic printing layer, and correspondingly obtain the printing trajectories of each color layer based on the shrunk preset distance.

9. The printing method of the three-dimensional printed object according to claim 1, characterized in that, The step of respectively stacking and printing multiple current outer wall color layers in the edge area of the printing surface of the object to be printed and printing the current basic printing layer in the middle area of the printing surface includes: Respectively use the stereolithography ink technology to stack and print multiple current outer wall color layers in the edge area of the printing surface of the object to be printed and use the fused deposition modeling technology to print the current basic printing layer in the middle area of the printing surface.

10. A three-dimensional printed object, characterized in that, The three-dimensional printing object is printed by the printing method of the three-dimensional printing object according to any one of claims 1-9 above, and includes: A printing main body, the printing main body includes multiple basic printing layers stacked and arranged in a fitting manner; A color shell, the color shell wraps the exposed side of the printing main body, and the color shell includes multiple outer wall color layers stacked and arranged in a fitting manner; Wherein, the outer wall color layer and the base printing layer are stacked with respect to the same horizontal plane, and the thickness of the outer wall color layer is less than the thickness of the base printing layer.

11. The three-dimensional printed object according to claim 10, wherein, The three-dimensional printed object includes one or more of a vertical side wall, an inner inclined side wall, and a hanging side wall; The sides of the multiple base printing layers corresponding to the vertical side wall that are away from the printing body are flush, and the sides of the multiple outer wall color layers corresponding to the vertical side wall that are away from the printing body are flush; In the direction from the bottom surface to the top surface of the three-dimensional printed object, the edges of the multiple base printing layers corresponding to the inner inclined side wall that are away from the printing body are gradually shortened layer by layer, and the edges of the multiple outer wall color layers corresponding to the inner inclined side wall that are away from the printing body are inclined layer by layer towards the side close to the printing body; In the direction from the bottom surface to the top surface of the three-dimensional printed object, the edges of the multiple base printing layers corresponding to the hanging side wall that are away from the printing body are gradually increased layer by layer, and the edges of the multiple outer wall color layers corresponding to the hanging side wall that are away from the printing body are inclined layer by layer towards the side away from the printing body.

12. The three-dimensional printed object according to claim 11, wherein The three-dimensional printed object further includes multiple fixed color layers, and the fixed color layers are stacked with the outer wall color layers; The side of the fixed color layer close to the printing body protrudes from the side of the corresponding outer wall color layer close to the printing body; and the part of the fixed color layer close to the printing body and protruding from the corresponding outer wall color layer is inserted into the printing body to be arranged in contact with every two adjacent base printing layers.

13. The three-dimensional printed object according to claim 11, wherein, The base printing layer includes multiple outer printing layers and inner printing layers; the thickness of the outer printing layer is less than the thickness of the inner printing layer.

14. The three-dimensional printed object according to claim 13, wherein The outer printing layer of the multiple base printing layers corresponding to the hanging side wall is an outer wall transmissive printing layer, and the outer wall transmissive printing layer extends towards the side away from the printing body until it is exposed; The fixed color layer is inserted between every two adjacent outer wall transmissive printing layers.

15. The three-dimensional printed object according to claim 10, wherein, The color layer further includes an end face color layer, and the three-dimensional printed object further includes an end face transmissive printing layer; The printing body includes at least one end face, and the end face color layer is arranged in contact with the end face; wherein, the end face includes a bottom surface, a bridge bottom surface, and a top surface; Wherein, when the end face is the bottom surface or the bridge bottom surface, the end face transmissive printing layer is arranged in contact with the side of the end face color layer away from the printing body.

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