CN108859097A - 3 D-printing method based on fluid support - Google Patents

Abstract

The invention discloses a kind of 3 D-printing methods based on fluid support.This method comprises the following steps：(1) preparation support fluent material, is put into container；(2) threedimensional model to be printed is sliced, then uses printer print structure in the support fluent material of step (1)；(3) solidify after carrying out the structure of step (2) printing in support fluent material；(4) after the completion of solidifying, printed structure is taken out with strainer.Method of the invention is not required to additional designs, process support structure, can expand the range of structures for being suitable for printing processing, promotes printing yields, simplifies aftertreatment technology, reduces printing cost.

Description

3D printing method based on fluid support

technical field

The invention belongs to the technical field of three-dimensional printing, and in particular relates to a three-dimensional printing method using fluid as a supporting material.

Background technique

The 3D printing technology based on additive manufacturing is a new processing and manufacturing technology in recent years, which has revolutionary significance. After decades of development, the current three-dimensional molding technology is relatively mature, mainly including the following types: material extrusion molding, light curing molding, powder coating laser sintering molding, etc.

The principle of the current 3D printing technology is mainly to print materials into two-dimensional graphics, and form various three-dimensional structures by vertically accumulating and stacking layer by layer. Due to the self-weight of the material, 3D printing technology requires an additional support when manufacturing overhanging structures and moving parts to prevent the processed structure from being deformed, moving and failing during printing. Various powder-based 3D printing technologies, including Selective Laser Melting, Selective Laser Sintering, and Inkjet Powder Printing, all use solid powder as a support. This type of technology uses laser heating or inkjet bonding to make the powder in the treated area combined and formed, and the rear platform moves down to a single layer height, laying down a layer of solid powder and processing, thereby realizing the three-dimensional structure manufacturing through circulation. The untreated powder in the process exists around the processed structure and becomes a support with a supporting and fixing effect. Various non-powder single-material 3D printing technologies, such as Fused Deposition Manufacturing, Stereo Lithography Appearance, Digital Light Processing, Microdrop Printing, etc., In the printing model design stage, it is necessary to design and add additional support structures according to the structural characteristics of the model. The auxiliary structure designed during the printing process will form a solid support to support and fix the manufactured structure. After the printing is completed, the Added fabricated structures require clipping to remove. Various non-powder multi-material 3D printing technologies, including fused deposition modeling (Fused Deposition Manufacturing), microdrop jetting (Microdrop Printing), etc., introduce soluble solid materials, use multiple materials alternately during the printing process and stack them layer by layer. To realize the manufacture of complex three-dimensional structures, the printed soluble solid material is used as a support, and after completion, a suitable solution is used to dissolve and remove the support to obtain the finished three-dimensional structure.

It can be seen that the current 3D printing technology uses solid materials as the support of the manufactured structure to ensure reliable processing of complex 3D structures including overhanging structures and moving parts. After the printing is completed, the three-dimensional structures produced by some printing technologies need to be finished in addition to routine cleaning, including removing the support structure and polishing the surface. These extra steps increase the production time and overall manufacturing cost of 3D printing. At the same time, the current 3D printing technology also requires the processed materials to have high strength, so as to avoid the failure of printing due to force deformation under the action of its own weight, thus limiting the range of applicable materials.

Contents of the invention

Aiming at the existing 3D printing technologies that use solid materials as supports, and the various deficiencies of the corresponding technologies in the printing process and post-processing links, this invention proposes a printing method that uses fluid as a deformable support, and the support body does not need additional design. It can expand the range of structures suitable for printing processing, improve the printing yield, simplify the post-processing process, and the fluid can be reused, which will effectively reduce the overall cost of printing.

In order to realize the foregoing invention object, the technical scheme that the present invention adopts is as follows:

A three-dimensional printing method based on fluid support, comprising the following steps: (1) preparing a support fluid material and putting it into a container; (2) slicing the three-dimensional model to be printed, and then using a printer to print in the support fluid material in step (1) structure; (3) post-curing the structure printed in step (2) in the supporting fluid material; (4) after the curing is completed, take out the printed structure with a colander.

Further, in the step (1), the supporting fluid material is a viscous liquid with a viscosity above 100 cps, or a solid-like fluid.

Further, in the step (2), the printer adopts a fused deposition modeling three-dimensional printer, a droplet injection molding three-dimensional printer, a direct writing three-dimensional printer or a glue dispenser.

Further, in the step (2), the material of the printed structure is a polymer material or a polymer-based composite material.

The present invention proposes a new three-dimensional printing method using fluid as a supporting material, and utilizes the flow characteristics of the fluid to realize dynamic deformation during the printing process. Compared with the prior art, the present invention has the following beneficial effects:

(1) A variety of traditional 3D printing technologies have many restrictions on the processed model structure. For complex structures such as overhanging structures, multi-layer nested structures, and moving parts, additional supports are required to support and fix the manufactured structures. , especially for external solid support structures, it is necessary to design on the target model in the modeling stage. Although this process can be assisted by a large number of commercial or open source software, it often requires the manual participation of experienced operators. The structure of the model determines the orientation of the printed model and adds or removes some key supports. The 3D printing method using fluid as support proposed by the present invention does not need to add additional supports, which eliminates the steps of supporting structure design in the modeling stage, greatly reduces the printing and design experience requirements for operators, can effectively reduce personnel training costs, and also Easy to promote to the public.

(2) The solid material support required by traditional 3D printing technology will bring additional material consumption during printing. For various printing technologies based on powder, due to the limited recovery rate of the powder used for support, they cannot all be used for printing again, resulting in the loss of printing materials. For the printing technology that uses an external structure as a support, printing the support structure will inevitably increase the consumption of printing materials, which will significantly increase the cost of raw materials. For the multi-material printing technology based on soluble support, the support structure needs to be removed by dissolution. Although the support material can be partially recycled, it will inevitably increase the overall cost. The three-dimensional printing method using fluid as support proposed by the present invention does not need to add additional support, which can effectively save printing materials, and the support fluid can also be reused, thereby effectively reducing the cost of printing raw materials.

(3) If the traditional 3D printing technology introduces an external support structure, the manufactured 3D structure requires post-processing before it can be used as a printed product, including removing the support structure and polishing the surface where the support structure was removed. The steps also add to the complexity and cost of manufacturing.

(4) Various existing 3D printing technologies have many restrictions on the modulus, strength and printing size of the material itself, so as to avoid printing failure caused by the deformation of the processed structure due to its own weight. The printing method of the present invention can print traditional high-strength materials with strong self-supporting ability, or materials that do not have self-supporting ability, such as liquid, uncured cross-linked rubber, resin and powder materials.

(5) The fluid support material proposed by the present invention has the following effects: it can resist the gravity or buoyancy of the material printed inside it, and the printed material will not sink or float in the fluid; it can lock the printed lines or graphics In the programmed position, it will not drift in the fluid. This fluid has a supporting and shaping effect on printing materials, and can realize the printing of various complex 3D models, including multi-layer nested structures, suspended structures, moving parts, etc.

(6) The printing method of the present invention is compatible with a variety of three-dimensional printing technologies, such as Fused Deposition Manufacturing (Fused Deposition Manufacturing), droplet jetting (piezoelectric, pneumatic, etc. drive methods) and Direct Ink Writing (including air pressure extrusion) , screw extrusion, syringe pump extrusion and other extrusion methods), etc. The fluid involved in the present invention has a wide range of choices, and can use water phase, oil phase, solvent phase and various composite fluids, and will be adjusted according to the printed material composition, so as to avoid negative effects such as dissolution while achieving the deformable support effect. effect has wide applicability.

Description of drawings

Fig. 1 is a flow chart of the method of the present invention.

Figure 2 is a schematic diagram of a device printed by fused deposition modeling technology, 1-printer, 2-support fluid, 3-model, 4-heater, 5-filament.

Fig. 3 is a schematic diagram of a device printed by droplet jetting technology, 6-actuator, 7-connector, 8-glass wall, 9-raw material, 10-droplet.

Figure 4 is a schematic diagram of the device printed by direct writing molding technology, 11-container, 12-syringe, 13-slurry.

Fig. 5 is a schematic diagram of the printing process of the embodiment of the present invention.

Detailed ways

The three-dimensional printing method of the present invention, as shown in Figure 1, specifically includes the following steps:

1. Preparation of support fluid, which is a deformable dynamic support material for 3D printing structures. The fluid contains two types of materials: high-viscosity liquid and solid-like fluid:

(1) High-viscosity liquids, whose viscosity should be higher than 100cps (for non-Newtonian fluids, the test shear rate is 0.1s ^-1 ), are liquid under static conditions, and have intrinsic fluidity. During the printing process, as the print head slides in the fluid, the fluid around it can flow to fill the gap created by the movement of the print head, thereby fixing the printed material at the discharge position and relying on its viscosity It can effectively offset the gravity or buoyancy effect caused by the difference in density between fluid and 3D printing materials, and realize the support and fixation of the printed structure.

(2) The fluid can also be a solid-like fluid, and should have two typical rheological characteristics, namely solid-liquid transition and shear thinning. The solid-liquid transition is characterized by solid-like rigidity when the fluid is still, but when a sufficient force is applied and the shear stress on the material is greater than the yield point, the sample will flow and exhibit liquid characteristics; shear thinning The characteristic is that the fluid viscosity decreases with the increase of the shear rate. During printing, since the print head moves in the liquid, pushing the surrounding fluid to make it in a liquid state that is easy to flow, so that the gaps generated by the movement of the print head can be filled by flow, and these fluids are then in a static state. Gradually restore the solid-like characteristics and rely on its rigidity to play the role of a support, fixing the printed material at the discharge position.

2. Put the supporting fluid in the container, and the fluid area corresponds to the printable space of 3D printing. The size of the container and the volume of the fluid should be larger than the space range of the printed model. The material in the container should be compatible with the post-curing mode, such as high temperature resistance to meet the heat curing method, UV light transmission to meet the UV curing method, etc.

3. Slice the 3D model to be printed, and then use the printer to print it in a container filled with fluid. This method is compatible with a variety of mainstream 3D printing technologies, such as Fused Deposition Manufacturing (Fused Deposition Manufacturing), droplet jetting (piezoelectric, Pneumatic and other driving methods) and direct writing molding technology (Direct InkWriting, including pneumatic extrusion, screw extrusion, syringe pump extrusion and other extrusion methods), etc., the schematic diagrams are shown in Figures 2, 3 and 4.

4. According to application requirements, the printed structure can be post-cured in fluid. The post-curing process can achieve the curing shape of the material or further increase the strength of the material. The post-curing method can be flexibly selected based on the material system. For example, heat-curing resin, rubber, and composite materials can be post-cured in an oven for the entire container; photosensitive resins can be post-cured by ultraviolet radiation in a UV curing box.

5. After the curing is completed, the printed structure can be taken out with a colander. Due to the fluidity of the support fluid, the fluid will remain in the container and will not be carried out with the processed structure.

The present invention will be described in detail below in conjunction with specific embodiments. The present invention can be realized by using various material systems, and is not limited to the specific embodiments described in this specification. The purpose of providing this embodiment is to make the disclosure of the present invention more thorough and comprehensive to facilitate understanding.

Example 1

Step 1. Add 4.7%-5.2% nano-scale hydrophilic silica to the benzyl silicone oil with a viscosity of 50-100cps and a refractive index of 1.460-1.480, and disperse it evenly with planetary stirring. After the stirring is completed, you can get Fluid Support Material 2. It is filled in a glass container 11, and the container 11 is put into a vacuum defoaming machine to remove the air bubbles in the fluid under vacuum conditions for use.

Step 2: Add a latent curing agent to the epoxy resin and mix it evenly with planetary agitation. After the agitation is completed, the printing material is obtained and poured into the syringe 12 for use.

Step 3. In this example, a direct-writing 3D printer using air pressure extrusion is used to slice the model 3 to be printed, generate G code, and copy it to the controller of printer 1 with a U disk.

Step 4. Place the container 11 containing the oily fluid on the platform of the printer 1, execute the G code and use air pressure control to realize the continuous extrusion of epoxy resin, make it print smoothly in the fluid, and process layer by layer to form the target three-dimensional structure.

Step 5. After the printing is completed, put the container 11 into an oven at 160° C. and heat it for two hours to cure the model 3 .

Step 6. After the container 11 is cooled, take out the model 3 as a whole with a colander, and wash off the oily liquid on the surface of the model 3 with acetone.

Example 2

Step 1: Add 3%-5% magnesium lithium silicate nanopowder to the ultrapure water, disperse it evenly with needle tip ultrasound, and then let it stand for 24 hours until it is stable, and then obtain the supporting fluid 2 .

Step 2. Addition curing liquid silicone rubber is used to mix the two components, then add thickener and crosslinking retarder, and mix well with planetary stirring. After the stirring is completed, the printing material is obtained and poured into the syringe 12 to be used.

Step 3. In this example, a direct-writing 3D printer using air pressure extrusion is used to slice the model 3 to be printed, generate G code, and copy it to the controller of printer 1 with a U disk.

Step 4. Place the container 11 containing the support fluid 2 on the platform of the printer 1, execute the G code and use air pressure control to realize the continuous extrusion of silica gel, so that it can be printed smoothly in the hydrogel fluid and processed layer by layer to form Target 3D structure.

Step 5. After the printing is completed, the container 11 is sealed and placed in an oven at 80° C. for two hours to cure the model 3 .

Step 6. After the container 11 is cooled, take out the model 3 as a whole with a linear colander, and wash off the residual liquid on the surface of the model 3 with alcohol.

Claims (4)

1. The three-dimensional printing method based on fluid support, is characterized in that, comprises the steps: (1) Prepare a support fluid material and put it into a container; (2) slice the three-dimensional model to be printed, and then use the printer to print the structure in the supporting fluid material of step (1); (3) post-curing the structure printed in step (2) in a supporting fluid material; (4) After the curing is completed, take out the printed structure with a colander. 2. The three-dimensional printing method based on fluid support according to claim 1, characterized in that, in the step (1), the support fluid material is a viscous liquid with a viscosity above 100 cps, or a solid-like fluid. 3. The three-dimensional printing method based on fluid support according to claim 1, wherein in the step (2), the printer adopts a fused deposition modeling three-dimensional printer, a droplet injection molding three-dimensional printer, a direct writing three-dimensional printer or Dispenser. 4. The three-dimensional printing method based on fluid support according to claim 1, characterized in that, in the step (2), the material of the printed structure is a polymer material or a polymer-based composite material.