阅读说明：本技术 一种免去除支撑的3d打印方法 (3D printing method free of removing support ) 是由 王莉 施森 王科 谭鸿迪 王宁 卢秉恒 于 2019-10-12 设计创作，主要内容包括：本发明涉及3D打印技术领域,具体涉及一种免去除支撑的3D打印方法,主要包括以下步骤：1)测试所需打印材料在多组工艺参数成型设备打印的固化深度或熔融烧结深度值,制作工艺参数表；2)对零件设计建模,确定分层厚度参数、成型设备工艺参数值,设计间隙支撑,将包含零件与间隙支撑的装配体文件导出STL模型文件；3)将STL模型文件导入切片软件,切片分析后生成加工文件；4)制作工艺参数设定,添加打印材料,检查设备状态,准备打印；5)设备打印开始,监控打印进程；6)取出零件实体部分,后处理获得零件。本发明在制造过程中打印件与支撑结构不粘连,可在确保有效支撑前提下,实现在后处理工艺中免去除支撑,成型效率高的优势。(The invention relates to the technical field of 3D printing, in particular to a 3D printing method without removing a support, which mainly comprises the following steps: 1) testing the curing depth or the fusion sintering depth value of the printing material to be printed on a plurality of groups of process parameter forming equipment, and making a process parameter table; 2) modeling part design, determining a layering thickness parameter and a forming equipment process parameter value, designing a clearance support, and exporting an assembly body file containing parts and the clearance support from an STL model file; 3) importing the STL model file into slicing software, and generating a processing file after slicing analysis; 4) setting manufacturing process parameters, adding printing materials, checking the equipment state and preparing for printing; 5) starting equipment printing, and monitoring a printing process; 6) and taking out the solid part of the part, and carrying out post-treatment to obtain the part. The printing part is not adhered to the supporting structure in the manufacturing process, so that the advantages of no support removal in the post-processing process and high forming efficiency can be realized on the premise of ensuring effective support.)

1. A3D printing method free of support removal is characterized by comprising the following steps:

1) testing the curing depth or the fusion sintering depth value of the printing material to be printed on a plurality of groups of process parameter forming equipment, and making a process parameter table;

2) modeling a part design, determining a layering thickness parameter according to the precision requirement of the part, selecting a curing depth or a melting sintering depth according to a printing material and the layering thickness, determining a process parameter value of a forming device according to a process parameter table in the step 1), analyzing a part structure, designing a gap support, ensuring that a gap exists between a part and a support interaction surface in the vertical direction through a part assembling distance relation, and exporting an assembly file containing the part and the gap support from an STL model file;

3) importing the STL model file into slicing software, placing a model, carrying out layering treatment on the part and the gap support according to the layering thickness value determined in the step 2), setting parameters for the solid part of the part according to the requirements of the part, setting parameters for the gap support according to the supporting requirements, and generating a processing file after slicing analysis;

4) setting manufacturing process parameters, setting the molding equipment according to the molding equipment process parameter values determined in the step 2), adding printing materials, checking the equipment state, and preparing for printing;

5) starting equipment printing, and monitoring a printing process;

6) and after printing is finished, taking out the solid part of the part, and performing post-processing to obtain the part.

2. A support-free 3D printing method according to claim 1, wherein:

in the step 2), a CAD technology is utilized to model the design of the part and the support.

3. A support-free 3D printing method according to claim 1 or 2, wherein:

in the step 2), the vertical gap distance between the part and the gap support is required to be larger than the difference between the solidification depth or the fusion sintering depth and the layering thickness.

4. A support-free 3D printing method according to claim 3, wherein:

in the step 1), the printing material is powder or paste with high solid content and high viscosity.

Technical Field

The invention relates to the technical field of 3D printing, in particular to a 3D printing method without removing a support.

Background

The 3D printing technology is based on the discrete/accumulation principle, and realizes part molding manufacturing by accumulating materials layer by layer. The 3D printing technology is used for printing the filamentous material, the powder material, the liquid material and the sheet material layer by layer through processes of melting extrusion, sintering, photocuring, cutting and the like, and printing pieces with complex structures and special-shaped structures can be printed by bonding and superposing the layers. The 3D printing technology can select a proper printing process according to the performance requirement of a printed piece, and can also control the precision and mechanical property of the printed piece by adjusting the process parameters such as layering thickness, strickling characteristics, scanning speed and the like.

Due to the principle that the printing layer by layer and the superposition layer by layer are carried out in the 3D printing process, the printed part with the cantilever characteristic structure is bent and deformed under the action of gravity in the printing process, and the forming precision of the printed part is influenced or even the final printing fails. Therefore, a reasonable supporting structure is necessary to be added to the printing piece with the cantilever characteristic structure in the printing process. The reasonable construction of the supporting structure can effectively solve the deformation problem of the cantilever characteristic structure of the printed piece, and meanwhile, the process of removing the support in the post-treatment process of the printed piece is increased. When more supporting structures need to be added to a printed piece, the post-processing support removing work takes long time, and the forming efficiency is greatly reduced. Meanwhile, the removal of the support structure may affect the mechanical properties and forming accuracy of the printed product.

At present, most researches are focused on solving the problem of support optimization design, and few researchers propose a support-free printing method and a water-soluble support material printing technology, wherein the support can be dissolved and fall off in a water solution under certain conditions by utilizing the water-soluble characteristic of the support in a post-treatment process, the two methods can effectively solve the problems that the support is difficult to remove and the fine surface quality of a part is influenced in the post-treatment process, but the two methods are very limited in application range, special forming equipment or special materials are required to be used, and the two methods cannot be realized by the existing forming equipment and materials.

Therefore, the elimination of the support-free printing method remains a problem that needs to be solved in the art.

Disclosure of Invention

In order to solve the problems in the background art, the invention provides the 3D printing method without removing the support.

The technical scheme for solving the problems is as follows: the 3D printing method without removing the support is characterized by comprising the following steps of:

1) testing the curing depth or the fusion sintering depth printed by a plurality of groups of process parameter forming equipment under various printing materials, manufacturing a curing depth or fusion sintering depth process parameter table of related materials and process parameters, and providing data preparation for later printing;

2) modeling the part design, reasonably determining a layering thickness parameter according to the precision requirement of the part, reasonably selecting a curing depth or a melting sintering depth according to a printing material and the layering thickness, determining a process parameter value of a forming device according to a process parameter table in the step 1), simultaneously analyzing the structure of the part, reasonably designing a gap support, ensuring that a certain gap exists between the part and a support interaction surface in the vertical direction through the relation of the assembly distance of the part, and exporting an assembly file containing the part and the gap support from an STL model file;

3) importing the STL model file into slicing software, reasonably placing a model, carrying out layered processing on the part and the gap support according to the layered thickness value determined in the step 2), setting other parameters such as filling rate and the like for the solid part of the part according to the requirements of the part, setting parameters for the gap support according to the supporting requirements, and generating a processing file after slicing analysis;

4) setting manufacturing process parameters, setting the molding equipment according to the molding equipment process parameter values determined in the step 2), adding printing materials, checking the equipment state, and preparing for printing;

5) starting equipment printing, and monitoring a printing process;

6) and after printing is finished, taking out the solid part of the part, and performing post-processing to obtain the part.

Further, in the step 2), the part and the support design are modeled by using a CAD technology.

Further, in step 2), to ensure that the gap support and the component are absolutely not bonded, the vertical gap distance between the component and the gap support is usually greater than the difference between the solidification depth or the fusion sintering depth and the delamination thickness.

Further, in the step 1), the printing material is a material with certain bearing characteristics, such as a paste or powder with high solid content and high viscosity, so that the parts can be prevented from sinking again, and the forming precision in the printing process can be ensured.

The invention has the advantages that:

(1) according to the invention, by utilizing the designed clearance support, under the condition of effectively supporting the cantilever structure, the support does not need to be removed, so that the post-processing process steps can be simplified, and the forming efficiency is greatly improved;

(2) according to the invention, the clearance support is designed in the CAD design stage, and the assembly body file containing the parts and the clearance support is exported out of the STL model, so that the implementation is convenient, no specific trimming software is required, and the feasibility and the applicability are strong;

(3) according to the invention, a support removing method is omitted, post-treatment is not needed after printing to remove the support, the problem that the part forming precision and the surface quality are damaged in the support removing link can be effectively avoided, and the qualified rate of printed parts is greatly improved;

(4) the invention is suitable for traditional powder or paste, can realize removal-free support printing under the conditions of the existing materials and forming equipment, has wide application range and has good application prospect.

Drawings

FIG. 1 is a diagram of a gap support structure in relation to a print according to the present invention;

FIG. 2 is a schematic representation of cure depth versus ply thickness in the present invention;

FIG. 3 is a schematic illustration of the present invention proposed to add support to cure nonblocking;

FIG. 4 is a view of a shaft part and a gap supporting pattern;

fig. 5 is a DLP print exposure layer diagram.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.

The principle of the invention is as follows:

the method for preventing the gap between the part and the gap supporting action surface from being not adhered is used, and particularly, materials with certain bearing performance, such as paste with the characteristics of high viscosity and high solid content and powder with the characteristics of certain supporting strength are used as printing materials, the method has certain supporting performance on the part above, and can effectively prevent the part from sinking under the action of gravity in the printing process due to the tiny gap in the printing process, so that the problem of printing fault layers is solved. Therefore, as shown in fig. 1, the elimination of the support in the post-treatment process can be realized on the premise that the effective support can be ensured by the tiny gap between the gap support and the action surface of the part.

The principle of vertical clearance distance between the clearance support and the action surface of the part is as follows: in order to ensure that the support structure and the printed material are stacked layer by layer and bonded layer by layer without falling off, as shown in fig. 2, generally the curing depth or the melting sintering depth is often larger than the layering thickness, according to the principle, the support structure and the printed material are not bonded, and a certain vertical gap is required to be reserved between the support and the action surface of the part, as shown in fig. 3, when the vertical gap value is required to ensure that the next layer is cured or melted and sintered, the deepest curing position or melting sintering position is above the support entity, the vertical gap distance value is larger than the difference value between the curing depth or the melting sintering depth and the layering thickness, so that the part and the support are not bonded, and when the vertical gap value is the difference value between the curing depth and the layering thickness, the two are not bonded, so that the support structure and the.

A3D printing method without support removal is disclosed, taking ceramic paste photocuring forming process as an example, firstly, modifying ceramic powder alumina, adding the modified ceramic alumina powder into low-viscosity photosensitive premixed liquid prepared by mixing a photoinitiator, an active diluent and a prepolymer, and stirring to obtain photosensitive paste with solid content of 70-90 wt%.

Specifically, the method comprises the following steps:

1) the curing depth process parameter table of the forming equipment under the parameters of a plurality of groups of light source power, a plurality of groups of exposure time or scanning speed and the like is measured by experiments;

2) designing and modeling the shaft part by utilizing a CAD technology, reasonably determining the layering thickness to be 50 mu m according to the precision requirement of the part, reasonably selecting the technological parameter values of forming equipment according to the printing material and the layering thickness, designing a gap supporting structure, and exporting an STL model file which comprises the part and the gap support simultaneously as shown in figure 4, wherein the vertical gap distance between the part and a supporting action surface is 20 mu m (more than 0.3 times of the layer thickness);

3) importing the STL model file into DLP printing slicing software, carrying out layering treatment on the part and the gap support according to the layering thickness of 50 mu m determined in the step 2), generating 580-layer slicing exposure sections as shown in figure 5, and generating a G code processing file;

4) setting manufacturing process parameters, setting the molding equipment according to the molding equipment process parameter values determined in the step 2), adding printing materials, checking the equipment state, and preparing for printing;

5) starting equipment printing, and monitoring a printing process;

6) and (5) after printing is finished, taking out the solid part of the part, and performing prototype post-processing to obtain the part.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures or equivalent flow transformations made by using the contents of the specification and the drawings, or applied directly or indirectly to other related systems, are included in the scope of the present invention.