Preparation method of powder product
By dividing the curing printing area and setting compensating supports in the binder jet molding technology, the problem of uneven densification of the lower surface of the powder bed was solved, and the consistency of the upper and lower surface quality of the powder product and the improvement of the mechanical properties were achieved.
Patent Information
- Application Number
- CN202510891248.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-30
- Publication Date
- 2025-10-03
AI Technical Summary
During the printing process of existing binder jet molding technology, non-uniform densification areas are easily formed on the lower surface of the metal powder bed, resulting in step effects, contour distortion and pore defects on the lower surface after sintering, affecting the quality and mechanical properties of parts.
By dividing the curing printing area on the two-dimensional slice and adopting different inkjet spacing and compensation support methods, it is ensured that each layer of the powder product has a support or fixing ring to prevent the powder from loosening and lateral diffusion, thereby improving the lower surface quality.
It effectively improves the consistency of the upper and lower surface quality of powder products, reduces the roughness difference, and improves the overall mechanical properties and appearance quality of the parts.
Smart Images
Figure CN120734346A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of additive manufacturing, and in particular to a method for preparing a powder product using a bonding spray molding technology. Background Art
[0002] Binder Jetting Additive Manufacturing (BJ) is a metal additive manufacturing technology based on the principle of "surface forming". Its core process flow is: liquid binder is precisely sprayed onto the pre-laid metal powder layer through a piezoelectric nozzle, and the powder layer is densified and evenly laid under the synergistic action of the double compaction powder rollers, and a three-dimensional green body is formed after layer-by-layer stacking. This technical route finally obtains metal parts with engineering application value through post-processing steps such as low-temperature curing of the binder skeleton, degreasing and high-temperature sintering. Compared with high-energy beam additive manufacturing technologies such as selective laser melting (SLM) and electron beam melting (EBM), BJ technology has become an important technical path for the production of mass-customized metal parts due to its high-throughput forming efficiency, sub-millimeter forming accuracy and significant cost advantages.
[0003] However, the existing BJ process suffers from a critical flaw that hinders its industrial application: during the printing process, the lower surface of the metal powder bed remains in an unconsolidated, loose state, which easily leads to non-uniform densification under the mechanical action of the double-compaction powder rollers. This difference in the powder bed state leads to non-synergistic effects between the binder injection zone and the compaction zone. Specifically, the lower surface region exhibits feature loss (such as step effects and contour distortion) due to a lack of effective support, while the binder penetration path is blocked, resulting in insufficient sintering activity in localized areas. More seriously, this non-uniform densification phenomenon accumulates with the number of printed layers, ultimately leading to systematic porosity defects on the lower surface of the sintered part (porosity can reach 5% to 15%), significantly degrading mechanical properties (such as fatigue life reduction of over 40%). The industry has yet to establish an effective solution, resulting in significant asymmetry between the upper and lower surface quality of BJ-printed parts. This defect is particularly prominent in the manufacturing of consumer electronics and medical devices, which have stringent requirements for surface quality, and has seriously hindered the industrialization and promotion of BJ technology in high-end manufacturing. Summary of the Invention
[0004] In view of the problems that the lower surface of the above powder products has a step effect and contour distortion due to the loose powder base, and there are serious voids on the lower surface after sintering, as well as a large difference in upper and lower surface quality.
[0005] Given that when using binder jetting technology to print powder products, the lower surface of the product is in direct contact with the loose powder bed. When subjected to roller compaction, the powder tends to diffuse and flow laterally. This can lead to two major problems: first, the amount of powder in the lower surface area of the product is reduced, resulting in a lower density; second, the loose powder bed forms an uneven, rough cross-section. Furthermore, this rough surface makes it easier for the sprayed binder droplets to diffuse longitudinally along the pores of the powder bed, resulting in insufficient ink in the lower surface area, ultimately leading to a decrease in structural strength in this area. Therefore, it is necessary to propose a preparation method for powder products that can effectively improve the consistency of the upper and lower surface quality of powder products produced using binder jetting.
[0006] A method for preparing a powder product, comprising slicing a three-dimensional model of the product, wherein the method for slicing the three-dimensional model of the product comprises:
[0007] S01, 2D slicing, cutting the 3D model of the product into several 2D slices;
[0008] S02, 2D slice analysis, obtain the total number of 2D slice layers N and the printing contour data L of each layer i (1≤i≤N);
[0009] S03, print area division, divide each layer of two-dimensional slice into a regular print area and a curing print area, the method of printing area division is to divide L i+1 Layer and current layer L i The printing contour data of the layer is subtracted to obtain the solidified printing contour data T i , that is, T i =L i+1 -L i ; Specifically, if T i is a negative value, that is, L i+1 The area of the layer is smaller than the current layer L i The area of the layer, the current layer L i Layer relative L i+1 The exposed area of the layer is the solidified printing area of the current layer, and the remaining printing area is the regular printing area; otherwise, give T i Assign the calculation result and lay out the solidified printing area on the current layer L i The outer layer forms the current layer L i The outer curing printing area of the layer, correspondingly, L i The print outline data of the entire layer area consists of L i The general printing area of the layer;
[0010] S04, printing of powder products, using a first printing method to print a conventional printing area of N layers of two-dimensional slices, and using a second printing method to print a solidified printing area of N layers of two-dimensional slices.
[0011] Through the implementation of the above technical solution, each layer of two-dimensional slices has a corresponding support or fixing ring, thereby avoiding the problem of reduced powder amount and lower density of the powder product caused by the powder being squeezed out of the contour range of the powder product due to compaction in a loose powder state. In addition, the solidified printing area with the support and fixing ring function can provide support and fixing for the next layer of powder surface.
[0012] Furthermore, the inkjet volume of the first printing method is the amount of ink required to prepare each two-dimensional slice of the powder product; the inkjet volume for preparing a single layer of the powder product is defined as the first inkjet volume; that is, the first printing method involves spraying the first inkjet volume once on each two-dimensional slice. Specifically, the inkjet pitch of the first printing method is no greater than -30μm at a resolution of 800DPI.
[0013] Furthermore, the second printing method involves spraying the first inkjet volume at least twice onto the cured print area, strengthening the cured print area and effectively avoiding the problem of reduced powder volume and density on the lower surface caused by lateral diffusion of the powder due to compaction force. Specifically, the inkjet pitch of this second printing method is no greater than 31.75 μm at a resolution of 800 DPI.
[0014] Improve printing efficiency by setting different inkjet spacing.
[0015] Another improved technical solution can avoid the surface quality problem of the product caused by the adhesion between the outer contour of the product and the surface of the product due to the reinforcement of the outer contour of the powder product in the above-mentioned technical solution. A compensation support method is proposed. Specifically, the compensation support is at least two compensation layers arranged below the first two-dimensional slicing layer of the powder product, and the printing contour data of the compensation layer is the same as that of the two-dimensional slice of the powder product.
[0016] Furthermore, the method for preparing the powder product having the compensation layer comprises:
[0017] S11, two-dimensional slicing, dividing the three-dimensional model of the product into several two-dimensional slices;
[0018] S12, 2D slice analysis, obtain the total number of layers N of the 2D slice and the printing contour data L of each layer i (1≤i≤N);
[0019] S13, set M layers of compensation layers below the first layer of two-dimensional slices. The printing contour data of the compensation layers is the same as the printing contour data L1 of the first layer of the two-dimensional slices of the powder product. The printing contour data of the compensation layers is recorded as B j (1≤j≤M);
[0020] S14, dividing the compensation layer area, calculating the difference between the printing contour data of each compensation layer and the second two-dimensional slice layer, and obtaining the solidified printing area T of the compensation layer. i , T i =L2-B j , solidify the printed area T i Set on the periphery of each compensation layer, the M-th compensation layer sets the M-layer curing printing area, the compensation layer and the first layer of two-dimensional slices have the same printing contour as the regular printing area of the compensation layer, and the additional M-layer curing printing area is the curing printing area of the compensation layer;
[0021] S15, powder product printing, using a first printing method to print N layers of two-dimensional slices and a conventional printing area of the compensation layer, and using a second printing method to print a solidified printing area of the compensation layer.
[0022] By arranging a compensation layer under the first layer of the powder product, a base layer with a certain hardness and a certain supporting effect is provided for the first layer of the powder product, thereby effectively avoiding defects on the lower surface of the powder product caused by dispersion of the base layer under compaction.
[0023] Furthermore, to avoid excessive ink waste and maintain printing efficiency, the compensation layer utilizes spot printing. This involves evenly sampling 30% to 70% of the points in the regular print profile data within the regular print area of the compensation layer as printing points. These points are then printed using the first printing method. By using spot printing, only the selected points are printed, significantly reducing inkjet volume and conserving binder. This improves printing efficiency, avoids overhardening of the solidified print profile, and facilitates subsequent powder recycling.
[0024] Furthermore, the principle for selecting the number of printing dots is that the higher the printing process temperature, the fewer the number of extracted dots, and the lower the printing process temperature, the more the number of extracted dots.
[0025] Furthermore, in order to save inkjet volume, the first printing method can be used to print the solidified printing area of the compensation layer, and the spot printing and the first printing method can be used to print the regular printing area of the compensation layer, which improves the printing efficiency and reduces the difficulty of powder recovery and cleaning.
[0026] Furthermore, the removal or cleaning of the solidified print profile printed by the binder jet printing with a non-water-based component can also be performed by cleaning or washing the solidified print profile with an alcohol-based solvent, thereby ensuring the quality of the lower surface of the powder product.
[0027] As another supplement to the present technical solution, in order to ensure the printing efficiency of the product and the compactness and consistency of the outer surface of the product, a curing printing area can be set on the periphery of the product. The preparation method of the powder product with the peripheral curing printing area includes:
[0028] S21, two-dimensional slicing, dividing the three-dimensional model of the product into several two-dimensional slices;
[0029] S22, 2D slice analysis, obtain the total number of layers N of the 2D slice and the printing contour data L of each layer i (1≤i≤N);
[0030] S23, peripheral solidification area division, L i+1 Layer and current layer L i The printing contour data of the layer is subtracted to obtain the printing contour data T of the solidified printing area i , and will L i+1 Layer and current layer L i The absolute value of the difference between the layer's print contour data is assigned to T i , that is, T i =|L i+1 -L i |, will solidify the print contour data T of the print area i The area set on the periphery of the current layer is called the peripheral curing printing area of the current layer;
[0031] S24, powder product printing, adopting the first printing method to print N layers of two-dimensional slices, and adopting the second printing method to print the peripheral solidified printing area.
[0032] As a supplement to this embodiment, in order to facilitate powder cleaning and powder recovery, a sampling printing method is used to print the peripheral solidified printing area. In this embodiment, the sampling rate of the printing dots is 30%, and the small-step printing of the second printing method is sampled, with an inkjet pitch of 30μm.
[0033] As another supplement to this embodiment, in order to improve printing efficiency, the solidified printing area is printed by using the sampling printing plus the first printing method, wherein the sampling rate of the printing dots is 70% and the inkjet spacing is 35 μm.
[0034] The beneficial effects of the technical solution of the present invention are as follows: by dividing the solidification printing area on the two-dimensional slice and adopting the second printing method to print the solidification printing area, the problems of reduced density and increased surface texture of the lower surface of the powder product caused by the loose base layer are avoided, and the quality of the lower surface is effectively improved, so that the roughness difference between the lower surface and the upper surface is ≤Ra 1um, thereby ensuring the consistency of the quality of the upper and lower surfaces of the powder product. BRIEF DESCRIPTION OF THE DRAWINGS
[0035] Figure 1 It is a three-dimensional model of a tapered product;
[0036] Figure 2 This is a layer structure of an implementation method of the solution in Example 1;
[0037] Figure 3 This is a layer structure of another implementation of the solution in Example 1;
[0038] Figure 4 This is the layer structure of the solution in Example 2;
[0039] Figure 5 This is the layer structure of the solution in Example 3. DETAILED DESCRIPTION
[0040] In order to more clearly illustrate the technical solution of the present invention, the following description is of some typical embodiments of the present invention. For ordinary technicians in this field, other solutions can be obtained based on these embodiments without any creative work.
[0041] The technical solution of the present invention is used to print Figure 1 The cone-shaped powder product shown is made of metal powder.
[0042] Example 1
[0043] The method of solidifying the outer contour of the powder product is adopted. When the contour of the i+1 layer is larger than the contour of the i layer, in order to ensure the compactness and flatness of the i+1 layer powder surface, T is arranged on the periphery of the i layer. i Solidify the printed outline.
[0044] In one embodiment, a method for preparing a conical metal powder product, and a method for slicing a three-dimensional model of the product include the following:
[0045] S01, two-dimensional slicing, cutting the three-dimensional model of the product into several two-dimensional slices; specifically, Figure 1 The three-dimensional model of the product is cut in a direction parallel to the largest cross section;
[0046] S02, 2D slice analysis, obtain the total number of 2D slice layers N and the printing contour data L of each layer i (1≤i≤N); Specifically, the three-dimensional model of the product is divided into 100 layers with a thickness of 0.3 mm, that is, N=100;
[0047] S03, print area division, divide each layer of two-dimensional slice into a regular print area and a curing print area, the method of printing area division is to divide L i+1 Layer and current layer L iThe printing contour data of the layer is subtracted, and the area where the obtained printing contour data is located is the solidified printing area, and the rest of the area is the conventional printing area; specifically, the solidified printing area is recorded as T i , that is, T i =L i+1 -L i , if T i is a negative value, that is, L i+1 The area of the layer is smaller than the current layer L i The area of the layer, then give T i Assign a value of 0, otherwise give T i Assignment operation result; In this embodiment, if Figure 2 As shown, L i+1 -L i The value of is positive, that is, T i The value of is greater than zero, and the area of the next layer is greater than the area of the current layer, then T i Subsidy to current level L i The outer side of the layer forms a solidified printing area outside the edge of the current layer. All the printing contours of the current layer are regular printing areas, so that the solidified printing area is arranged in a surrounding form on the outer circle of the Li layer, playing a role of ring solidification. In another embodiment, as Figure 3 As shown, L i+1 -L i The value of T is negative, that is, i The value of is less than zero, and the area of the next layer is smaller than the area of the current layer, then the current layer L i The extra area for the next layer is the solidified printing area of the current layer, and the remaining area is the regular printing area;
[0048] S04, powder product printing, using the first printing method to print the conventional printing area for forming 100 layers of two-dimensional slices of the conical product, and using the second printing method to print the solidified printing area for forming the first 99 layers of two-dimensional slices of the conical product.
[0049] As a supplement to this embodiment, the inkjet volume of the first printing method is the amount of ink required to produce each two-dimensional slice layer of the powder product; the inkjet volume for producing a single layer of the powder product is defined as the first inkjet volume. In other words, the first printing method involves spraying ink once per two-dimensional slice layer with the first inkjet volume. Specifically, the inkjet spacing of the first printing method is no greater than 35μm-30μm at 800DPI resolution. In this embodiment, using an 800DPI print head, based on the print profile data of 100 two-dimensional slice layers, inkjet ink is sprayed once at a 35μm inkjet spacing on the two-dimensional slices of the printed product.
[0050] As a further supplement to the present technical solution, the second printing method is to spray the first inkjet amount on the solidified printing area at least twice to achieve the strengthening of the solidified printing area, thereby effectively avoiding the problem of reduced powder amount and reduced density on the lower surface due to lateral diffusion of powder caused by compaction force. Specifically, the inkjet spacing of the second printing method is no more than 31.75μm at a resolution of 800DPI. In this embodiment, a print head with an 800DPI resolution is used for the solidified printing area of the first 99 layers of the powder product, and each layer of the solidified printing area is sprayed twice with an inkjet spacing of 31.75μm to form a solidified printing area with a certain consolidation ability, ensuring that the i layer will not be loosened when compacted after the i+1 layer of powder is spread, causing problems such as reduced powder amount and uneven powder surface.
[0051] Example 2
[0052] By setting a compensation layer in the Z direction, when the outline of the i+1 layer is smaller than the outline of the i layer, in this case, as long as the base layer has a certain support, the subsequent powder surface can be guaranteed to be compact and smooth.
[0053] One implementation method, which can avoid the surface quality issues associated with the aforementioned technical solution, where the outer contour of the powder product adheres to the surface due to reinforcement of the outer contour, proposes a compensatory support method. Specifically, the compensatory support comprises at least two compensation layers disposed below the first layer of two-dimensional slices of the powder product, and the compensation layers have the same printed contour data as the two-dimensional slices of the powder product. In this implementation, there are two compensation layers: the first compensation layer has the same printed contour as the first layer of two-dimensional slices, and the second compensation layer also has the same printed contour as the first layer of two-dimensional slices, thereby effectively supporting the first layer of two-dimensional slices.
[0054] As a supplement to this embodiment, a method for preparing a powder product having a compensation layer includes:
[0055] S11, two-dimensional slicing, dividing the three-dimensional model of the product into several two-dimensional slices;
[0056] S12, two-dimensional slice analysis, obtain the total number of two-dimensional slice layers 80 and the printing contour data L of each layer i (1≤i≤80);
[0057] S13, set M layers of compensation layers below the first layer of two-dimensional slices. The printing contour data of the compensation layers is the same as the printing contour data L1 of the first layer of the two-dimensional slices of the powder product. The printing contour data of the compensation layers is recorded as B j (1≤j≤M);
[0058] S14, compensation layer area division, the two compensation layers and the second two-dimensional slice layer printing contour data difference is obtained to obtain the compensation layer solidification printing area T i , T i =L2-B j , the rest of the area is the regular printing area of the compensation layer; in this embodiment, Figure 4 As shown, a circle of curing printing areas is provided around the second compensation layer, and two circles of curing printing areas are provided around the first compensation layer, thereby forming a stable support for the lower surface of the powder preparation. That is, when the outline of the i+1 layer is smaller than the outline of the i layer, each layer is supported by the ground, avoiding the problem of reduced powder amount and uneven powder surface caused by the compaction of the upper layer due to loose ground support. Therefore, the compensation layer includes a conventional printing area with the same print outline as the first layer and a curing printing area provided on the periphery.
[0059] S15, powder product printing, using the first printing method to print 80 layers of two-dimensional slices and two layers of compensation layer in the regular printing area, and using the second printing method to print the solidified printing area of the compensation layer.
[0060] As a further supplement to this embodiment, to avoid excessive ink waste and maintain printing efficiency, the compensation layer utilizes spot printing. This spot printing method involves evenly sampling 30% to 70% of the regular printing profile data within the regular printing area of the compensation layer as printing points. The first printing method is then used to print these points within the regular printing area of the compensation layer. By employing spot printing, only the selected points are printed, significantly reducing inkjet volume and conserving binder. This improves printing efficiency, avoids excessive hardening of the compensation layer, and facilitates subsequent powder recycling. In this embodiment, the sampled print point data represents 45% of the regular printing profile data for the entire compensation layer.
[0061] As a further supplement to this embodiment, the principle for selecting the number of printing dots is that the higher the printing process temperature, the fewer the number of extracted dots, and the lower the printing process temperature, the more the number of extracted dots.
[0062] As a further supplement to this embodiment, to further improve printing efficiency and facilitate powder recovery, the cured printing area of the compensation layer can also be printed using the first printing method. In this embodiment, the inkjet pitch of the first printing method is 33μm, which ensures both efficiency and product compactness.
[0063] As a further supplement to this embodiment, in the first printing mode, the conventional area of the compensation layer is printed with an inkjet pitch of 35μm, and the cured printing area of the compensation layer is printed with a step pitch of 30μm, thereby improving the printing efficiency, ensuring that the powder-prepared compensation layer has a certain strength of support, and facilitating the recycling of the powder.
[0064] As a further supplement to this embodiment, the removal or cleaning of the solidified print profile printed by jet printing with a non-water-based binder can also be performed by cleaning or washing the solidified print profile with an alcohol-based solvent, thereby ensuring the quality of the lower surface of the powder product.
[0065] Through the implementation of this technical solution, a supporting base layer or a confining area with a certain strength is provided for the lower surface of the powder product, ensuring that when the i layer is compacted after the i+1 layer is spread, it will not be loosened, causing problems such as reduced powder amount and uneven powder surface.
[0066] Example 3
[0067] In order to ensure the printing efficiency of the product and the compactness and consistency of the outer surface of the powder product, a curing printing area can be set on the periphery of the powder product. The preparation method of the powder product with the peripheral curing printing area includes:
[0068] S21, two-dimensional slicing, dividing the three-dimensional model of the product into several two-dimensional slices;
[0069] S22, two-dimensional slice analysis, obtain the total number of two-dimensional slice layers 60 and the printing contour data L of each layer i (1≤i≤60);
[0070] S23, peripheral solidification area division, L i+1 Layer and current layer L i The printing contour data of the layer is subtracted to obtain the printing contour data T of the solidified printing area i , and will L i+1 Layer and current layer L i The absolute value of the difference between the layer's print contour data is assigned to T i , that is, T i =|L i+1 -L i |, will solidify the print contour data T of the print area i Set at the periphery of the current layer, called the peripheral curing printing area of the current layer; in this embodiment, if L i+1 -L i If it is not equal to zero, the solidified printing area is shifted to the current layer L i The outer layer is the outer curing printing area of the current layer. If L i+1 -Li If equal to zero, set at least two current layers L i The area of layer thickness is used as the peripheral curing print area;
[0071] S24, powder product printing, using the first printing method to print 60 layers of two-dimensional slices and a peripheral solidified printing area. In this embodiment, the inkjet spacing of the first printing method is 30 μm, thereby ensuring the tightness and density of the product bonding.
[0072] As a supplement to this embodiment, to facilitate powder cleaning and recovery, a spot printing method is implemented in the peripheral solidified print area, in addition to the first printing method. In this embodiment, the inkjet pitch of the first printing method is 35 μm, using the maximum inkjet pitch of the first printing method, and the print points are 70% of the data points of the print outline of the peripheral solidified print area. This improves printing efficiency while reducing inkjet volume, which in turn reduces the difficulty of subsequent powder recovery.
[0073] The above embodiment is only a description of a typical application of the technical solution of the present invention, and reasonable expansion can be made on a reasonable basis without requiring creative work.
Claims
1. A method for preparing a powder product, characterized in that: include, S01, 2D slicing, cutting the 3D model of the product into several 2D slices; S02, 2D slice analysis, obtain the total number of 2D slice layers N and the printing contour data L of each layer i (1≤i≤N); S03, print area division, divide each layer of two-dimensional slice into a regular print area and a curing print area, the method of printing area division is to divide L i+1 Layer and current layer L i The printing contour data of the layer is subtracted to obtain the solidified printing contour data T i , that is, T i =L i+1 -L i ; Current layer L i Layer relative L i+1 The exposed area of the layer is the solidified printing area of the current layer, and the remaining printing area is the regular printing area; Otherwise, give T i Assign the result of the operation and lay out the solidified printing outline data on the current layer L i The outer layer forms the current layer L i The outer edge of the layer solidifies the printed area, while L i The entire area of the layer is L i The general printing area of the layer; S04, printing of powder products, using a first printing method to print a conventional printing area of N layers of two-dimensional slices, and using a second printing method to print a solidified printing area of N layers of two-dimensional slices.
2. The method for preparing a powder product according to claim 1, wherein: The first printing method is to spray once on each two-dimensional slice with a first inkjet volume.
3. The method for preparing a powder product according to claim 2, wherein: The second printing method is to spray the first inkjet amount on the curing printing area at least twice.
4. A method for preparing a powder product, characterized in that: include, S11, two-dimensional slicing, dividing the three-dimensional model of the product into several two-dimensional slices; S12, 2D slice analysis, obtain the total number of layers N of the 2D slice and the printing contour data L of each layer i (1≤i≤N); S13, set M layers of compensation layers below the first layer of two-dimensional slices. The printing contour data of the compensation layers is the same as the printing contour data L1 of the first layer of the two-dimensional slices of the powder product. The printing contour data of the compensation layers is recorded as B j (1≤j≤M); S14, dividing the compensation layer area, calculating the difference between the printing contour data of each compensation layer and the second two-dimensional slice layer, and obtaining the solidified printing area T of the compensation layer. i , T i =L2-B j , solidify the printed area T i Set on the periphery of each compensation layer, the M-th compensation layer sets the M-layer curing printing area, the original compensation layer with the same printing contour as the first layer of two-dimensional slice is recorded as the regular printing area of the compensation layer, and the additional M-layer curing printing area is the curing printing area of the compensation layer; S15, powder product printing, using the first printing method to print N layers of two-dimensional slices and the conventional printing area of the compensation layer, and using the second printing method to print the solidified printing area of the compensation layer.
5. The method for preparing a powder product according to claim 4, wherein: The compensation layer is printed by sampling. The method of sampling is to evenly extract 30% to 70% of the dots in the regular printing contour data in the regular printing area of the compensation layer as printing dots, and use the first printing method to print the printing dots in the regular printing area of the compensation layer.
6. The method for preparing a powder product according to claim 5, wherein: The principle for selecting the number of printing points is that the higher the printing process temperature, the fewer the number of extraction points, and the lower the printing process temperature, the more the number of extraction points.
7. The method for preparing a powder product according to claim 4, wherein: The solidified printing area of the compensation layer may also be printed using the first printing method.
8. A method for preparing a powder product, characterized in that: include, S21, two-dimensional slicing, dividing the three-dimensional model of the product into several two-dimensional slices; S22, 2D slice analysis, obtain the total number of layers N of the 2D slice and the printing contour data L of each layer i (1≤i≤N); S23, peripheral solidification area division, L i+1 Layer and current layer L i The printing contour data of the layer is subtracted to obtain the printing contour data T of the solidified printing area i , and will L i+1 Layer and current layer L i The absolute value of the difference between the layer's print contour data is assigned to T i , that is, T i =|L i+1 -L i |, will solidify the print contour data T of the print area i The area set on the periphery of the current layer is called the peripheral curing printing area of the current layer; S24, powder product printing, adopting the first printing method to print N layers of two-dimensional slices, and adopting the second printing method to print the peripheral solidified printing area.
9. The method for preparing a powder product according to claim 8, wherein: In S23, if L i+1 -L i If equal to zero, set at least two current layers L i The area of the layer thickness is used as the peripheral curing print area.
10. The method for preparing a powder product according to any one of claims 8 or 9, characterized in that: Removal or cleaning of a cured print profile printed using a binder jet having a non-water-based composition can be performed by cleaning the cured print profile using an alcohol-based solvent.