WO2021003984A1

WO2021003984A1 - Water-cured 3d printing method and device

Info

Publication number: WO2021003984A1
Application number: PCT/CN2019/123108
Authority: WO
Inventors: 张津津; 郑丽娜; 贾凯杰; 朱梦梦; 李慧; 杨乃涛; 孟秀霞
Original assignee: 山东理工大学
Priority date: 2019-07-05
Filing date: 2019-12-04
Publication date: 2021-01-14
Also published as: CN110154387B; CN110154387A

Abstract

The present application relates to the technical field of three-dimensional (3D) printing, and in particular, to a water-cured 3D printing method and device. The method comprises: using a water-cured material or a slurry doped with the water-cured material as a raw material; loading the raw material into a material cylinder of a 3D printer; designing and drawing a pre-printed object model by using 3D drawing software; controlling the 3D printer to extrude materials in the material cylinder; and curing the materials by contacting with water so as to prepare an entity. The present application is a novel water-cured 3D printing method capable of being applied to various fields of production and life; without restrictions of conditions such as temperature and illumination, the water-cured material is used as the main component of the slurry, and can be cured and formed by simply contacting with water, the entity with arbitrary complex shape can be prepared, and the operation is simple and rapid; the heating is not needed, the energy is saved, and the consumption is reduced; a water-cured 3D printing process is free of pollution, operated at room temperature, is simple, convenient and feasible in operation, and is green and economical. The present application further provides a water-cured 3D printing device.

Description

Water curing 3D printing method and device

Cross references to related applications

This application claims the priority of the Chinese patent application with the application number 201910602083.4 and the title "Water curing 3D printing method and device" filed with the Chinese Patent Office on July 5, 2019, the entire content of which is incorporated into this application by reference.

Technical field

This application belongs to the field of 3D printing technology, and specifically relates to a water-cured 3D printing method and device.

Background technique

Different from the traditional manufacturing process of raw material removal-cutting and assembly, 3D printing is a "bottom-up" manufacturing method through material accumulation, which makes complex structural parts that were previously restricted by traditional manufacturing methods and could not be realized. Manufacturing becomes possible. In addition, 3D printing does not require molds in the manufacturing process, nor does it need to turn molds. The core idea of 3D printing technology is to deposit or superimpose materials layer by layer, and finally obtain three-dimensional components drawn by digital drawings. The basic principle is: digital layering-physical layering, that is, first establish a digital model of the printed object and perform digital layering to obtain the two-dimensional processing path or trajectory of each layer, and then select the appropriate material and corresponding process In this way, driven by the two-dimensional digital path of each layer obtained above, printing layer by layer, and finally the printed object is accumulated and manufactured.

At present, the more mature 3D printing methods include light curing molding technology (SLA and DLP), fused deposition molding technology (FDM), laser selective sintering technology (SLS) and inkjet printing molding technology (IJP). Among them, SLA and DLP technology have high molding accuracy, but due to the limitation of light curing principle, it is difficult to realize the printing of dark paste; FDM technology needs to heat and melt filamentous materials, which requires higher materials, and the melting point of printing materials is relatively low. It is difficult to realize the printing of high-boiling inorganic materials. SLS technology requires high-power lasers, high energy consumption, and expensive equipment. It mainly prints metal powders, and it is difficult to print and form inorganic materials with higher boiling points. IJP technology has great advantages in printing thin-film devices, but it is very difficult to prepare high aspect ratio devices with complex geometric configurations.

Summary of the invention

In view of the shortcomings of 3D printing methods such as light curing molding technology, fused deposition molding technology, laser selective sintering technology, and inkjet printing molding technology, the purpose of this application is to provide a water curing 3D printing method without material restrictions, no temperature and light, etc. Conditional restrictions, no heating, energy saving and consumption reduction, operation at room temperature, simple and easy operation, no pollution, green economy and broad development prospects; this application also provides a water curing 3D printing device.

The water-curing 3D printing method described in this application uses water-curable materials or slurry doped with water-curable materials as raw materials, fills the raw materials into a 3D printer barrel, uses three-dimensional drawing software to design and draw pre-printed physical models, and control The 3D printer squeezes out the material in the barrel and solidifies with water.

The water curing material is one or more of monomolecular polyurethane materials, silicate materials and water-based high molecular polymers.

The preparation method of monomolecular polyurethane materials is:

(1) Add polyethylene glycol and KOH to the reaction flask, dehydrate under the oil bath with a vacuum degree of 0.10-0.11MPa and a temperature of 100-102℃, and cool down to 68-70℃; vacuum and nitrogen replacement reaction Bottle, to remove the air in the reaction flask; keep the temperature unchanged, slowly add propylene oxide dropwise under the protection of nitrogen, and continue the reaction until there is no reflux phenomenon after the dropwise addition is complete, and cool to room temperature to obtain crude polyol ；

(2) Add dichloromethane to the crude polyol obtained in step (1), use a vacuum filtration device, replace the filter paper with diatomaceous earth to remove KOH, adjust the pH to 5±0.2, and add a desiccant calcium chloride to proceed. Concentrate to obtain polyol;

(3) Add the polyol obtained in step (2) into the reaction flask, add dibutyltin dilaurate catalyst and diphenylmethane diisocyanate under the condition of increasing the temperature to 48-50°C, and react for 1.4-1.6h , Then add antioxidant and ultraviolet absorber, heat preservation reaction for 1-1.1h, reduce the temperature to room temperature, add methyl ethyl ketone, and obtain the polyurethane prepolymer with the end group of -NCO group;

(4) Mixing the polyurethane prepolymer obtained in step (3) with water to prepare a hydrophilic one-component water-curable polyurethane.

Among them: the relative molecular weight of polyethylene glycol is 1000, and the relative molecular weight of polyethylene glycol is selected to make the slurry viscosity suitable for printing.

The mass ratio of polyethylene glycol, KOH, propylene oxide, dibutyltin dilaurate catalyst and diphenylmethane diisocyanate is 40:0.40-0.42:3.0-3.02:0.20-0.21:0.60-0.62.

The aforementioned monomolecular polyurethane materials have the advantages of acid resistance, alkali resistance, high temperature resistance and high mechanical strength.

The preparation method of silicate materials is:

35-40 parts by weight of tricalcium silicate, 5-5.5 parts by weight of calcium hydroxide, 3-3.5 parts by weight of tetracalcium phosphate, 5-5.5 parts by weight of calcium hydrogen phosphate, 4-4.5 parts by weight of hydroxyapatite Parts by weight, 8-8.5 parts by weight of hydroxybutyl chitosan, 5-5.5 parts by weight of tantalum pentoxide and 5-5.5 parts by weight of zirconium dioxide are mixed, dissolved in 27-29 parts by weight of water-soluble silicone oil, in a ball mill Ball milling and mixing are carried out for 10-14 hours to obtain silicate materials.

Preferably, the preparation method of the silicate material is: 37 g of tricalcium silicate, 5 g of calcium hydroxide, 3 g of tetracalcium phosphate, 5 g of calcium hydrogen phosphate, 4 g of hydroxyapatite, and hydroxybutyl shell with a particle size of less than 10 μm. 8 g of polysaccharides, 5 g of tantalum pentoxide and 5 g of zirconium dioxide were mixed, dissolved in 28 g of water-soluble silicone oil, and ball milled and mixed in a ball mill for 12 hours to obtain silicate materials.

The above-mentioned silicate materials have the advantages of simple preparation process, easily available materials and low cost.

The water-based polymer is polyethersulfone; the preparation method of the slurry doped with water-curable materials is: using ethanol as a solvent, mixing nickel oxide and yttria-stabilized zirconia at a mass ratio of 70:30, at 240 rpm Ball mill at a rotating speed for 12-13 hours. After drying and sieving the ball milled slurry, the anode powder is obtained. The above-mentioned anode powder, polyethersulfone and n-methylpyrrolidone are in a mass ratio of 7.9-8.1:1.0:3.0 -3.1 Mechanical stirring to obtain slurry doped with water-curable material.

Water-based polymer has the advantages of large molecular weight (generally above 10,000), unique structure, easy modification and easy processing.

This application uses water-curable materials or slurry doped with water-curable materials as raw materials, and uses three-dimensional drawing software to design and draw pre-printed physical models based on phase inversion principles and extrusion methods, and realizes by computer printing software to control the water-cured 3D printer The preparation of objects with arbitrary complex shapes. Preferably, the water-curing 3D printing method described in this application includes the following steps:

(1) Stir and dissolve the water-curing material in a solvent to prepare a slurry, and fill it into the 3D printer barrel;

(2) Use 3D drawing software to design and draw pre-printed physical models, slice and layer by 3D printing software, and use 3D printer to print in layers;

(3) The slurry in the 3D printer barrel is extruded from the material nozzle by pressure extrusion, and solidified on the forming platform to form a blank.

among them:

In step (1), the water-curable material is stirred and dissolved in a solvent. The solvent is methanol, ethanol or n-methylpyrrolidone. At the same time, inorganic powder is added to the slurry to prepare a paste slurry. The inorganic powder is hydroxide Calcium, tetracalcium phosphate or dicalcium phosphate.

The raw material obtained in step (3) is subjected to post-processing to obtain the actual product; the post-processing includes heat treatment or dip coating of the device to obtain the entity, and the heat treatment is degreasing or sintering.

The 3D drawing software is 3Dmax, Catia or UG.

The way of encountering water in step (3) can be water immersion or water spraying.

A device for realizing the water-cured 3D printing method includes a material cylinder, the material cylinder is arranged on a housing, the material cylinder is connected to a nozzle through a conveying pipe, and a lifting platform is arranged under the nozzle. The lifting platform is located inside the water tank, and the nozzle is connected to a sliding rod. The rod is connected to the driving device.

In the mixer, the water-curing material or the slurry mixed with the water-curing material is fully mixed by rotating and stirring, and then the slurry is pumped into the barrel by a pressure pump, and water is pumped into the tank at the same time, and then the slurry is pressurized by the air pump Extruding from the nozzle, the air pump is preferably connected to a computer and a controller, and the computer and the controller control the pressure of the air pump to maintain the required pressure, thereby controlling the spraying speed of the slurry. At the same time, lower the lifting platform to the lower tank so that the surface of the platform is full of water, then raise the lifting platform to receive the slurry sprayed by the nozzle, and then lower the lifting platform so that the slurry is completely immersed in the water, repeat the above process until the lifting The slurry on the platform is solidified and formed to obtain a solidified part of the required shape, and the printing and solidification are completed, and the printing of the required sample is finally completed.

Among them: according to the required shape of the raw body, choose nozzles of different shapes (such as circular nozzles for round raw bodies, and square nozzles for square raw bodies). The size of the raw body can be adjusted by the nozzle opening.

The front and back travel speed of the spray head and the lifting speed of the lifting platform are the speed at which the embryo body is formed.

In this application, the slurry is pumped into the barrel, and then the pressure difference is used to make the slurry enter the nozzle from the barrel through the conveying pipe and then spray the slurry. In this process, the system can continuously and stably transport the material.

In this application, the slurry is pumped into the barrel, and the pressure difference between the barrel and the nozzle is kept within a certain range to control the spray speed of the water-cured slurry. The slurry in the nozzle is extruded under pressure and solidified on the lifting platform. The cured part is formed into the required shape to realize the simultaneous printing and curing, and finally the printing of the required sample is completed.

Compared with the prior art, this application has the following advantages:

(1) The water-cured 3D printing method described in this application has no material restrictions, no temperature and light conditions, no heating, and energy saving and consumption reduction. It can be cured only when it meets water, and the water-curing 3D printing process is pollution-free. It is easy to operate at room temperature and can be applied to various fields of production and life according to actual needs. Model data can be made into solid models at low cost, green economy, and broad development prospects.

(2) The water-curing 3D printing device provided by the present application has a simple and reasonable structure, can realize the solidification and molding of slurry in water, and is simple and quick to operate.

Description of the drawings

FIG. 1 is a schematic diagram of the structure of the water curing 3D printing device in Example 1;

In the picture: 1-shell, 2-barrel, 3-conveying pipe, 4-nozzle, 5-lifting platform, 6-sink.

Detailed ways

The application will be further described below in conjunction with embodiments.

Example 1

A water curing 3D printing method includes the following steps:

(1) 40g polyethylene glycol with a relative molecular mass of 1000 and 0.4g KOH were added to a four-necked flask, dehydrated for 1 hour under the conditions of an oil bath with a vacuum of 0.1MPa and a temperature of 100°C, and the temperature was reduced to 70°C;

(2) Connect the condenser, thermometer and nitrogen interface to the four-necked flask, evacuate and replace with nitrogen 5 times to remove the air in the four-necked flask; keep the temperature unchanged, and pass through under nitrogen protection Slowly add 3 g of propylene oxide dropwise to the constant pressure dropping funnel, continue the reaction until there is no reflux phenomenon after the dropwise addition is completed, and cool to room temperature to obtain a crude polyol;

(3) Add 80 mL of dichloromethane to the crude polyol obtained in step (2), use a vacuum filtration device, replace the filter paper with diatomaceous earth to remove KOH, adjust the pH to 5, and add a desiccant calcium chloride to proceed. Concentrate to obtain polyol;

(4) Add the polyol obtained in step (3) to a three-necked flask equipped with a thermometer and an electric stirrer, and add 0.20 g of dibutyltin dilaurate catalyst and 0.60 g of dibutyl tin dilaurate under the condition of raising the temperature to 50°C. Phenylmethane diisocyanate, react for 1.5h, then add 1.0g antioxidant and 0.10g ultraviolet absorber, keep the reaction for 1h, reduce the temperature to room temperature, add 4mL methyl ethyl ketone, obtain the polyurethane prepolymer with end group -NCO group;

(5) Weigh 10.0 g of the polyurethane prepolymer obtained in step (4) and mix with 10 mL of water to prepare a hydrophilic one-component water-curable polyurethane.

100g of monomolecular water-curable polyurethane, 2g of silane coupling agent and 10g of defoamer obtained in step (5) were stirred at 70°C for 20 minutes; the temperature was reduced to 60°C, and the vacuum was defoamed for 5 minutes at -0.07MPa to prepare Out the slurry. Fill the slurry into the 3D printer barrel; use the 3D drawing software to design and draw the pre-printed physical model, slice and layer with the 3D printing software, and use the 3D printer to print layer by layer; the slurry in the 3D printer barrel is extruded by pressure It is extruded from the material nozzle and solidified on the forming platform to form a blank.

A device for realizing the above-mentioned water curing 3D printing method, comprising a material barrel 2, the material barrel 2 is arranged on the housing 1, the material barrel 2 is connected to a nozzle 4 through a conveying pipe 3, a lifting platform 5 is arranged under the nozzle 4, and the lifting platform 5 is located in a water tank Inside 6, nozzle 1 is connected to a sliding rod, and the sliding rod is connected to a driving device.

The slurry is pumped into the barrel 2 by a pressure pump, and water is pumped into the tank 6 at the same time. The circular nozzle 1 is selected and the opening of the nozzle 1 is controlled to 3mm. Then the slurry is pressurized by the air pump to squeeze the slurry from the nozzle 4. The air pump is preferably connected to a computer and a controller, and the pressure of the air pump is controlled by the computer and the controller to maintain the required pressure, thereby controlling the spray speed of the slurry. At the same time, the lifting platform 5 is lowered in advance to the lower tank 6 so that the surface of the platform is soaked with water, and then the lifting platform 5 is raised to receive the slurry sprayed by the nozzle 4, and then the lifting platform 5 is lowered so that the slurry is completely immersed in the water, repeat In the above process, until the slurry on the lifting platform 5 is cured and formed to obtain a cured part of the desired shape, the printing and curing are completed, and the printing of the desired sample is finally completed.

Example 2

A water curing 3D printing method includes the following steps:

(1) Using ethanol as solvent, mixing nickel oxide and yttria stabilized zirconia at a mass ratio of 70:30, ball milling at 240 rpm for 12 hours, drying and sieving the ball milled slurry to obtain anode powder.

(2) The above-mentioned anode powder, polyethersulfone and n-methylpyrrolidone are mixed in a mixer with a mass ratio of 8:1:3 to fully mix the polyethersulfone slurry to obtain a slurry.

The slurry is pumped into the barrel through the pressure pump, and water is pumped into the tank at the same time. A round nozzle is selected and the nozzle opening is controlled to 3mm. At the same time, the computer and controller are operated to keep the air pump pressure at the required pressure to control the slurry The jetting speed is increased by the air pump to squeeze the slurry out of the nozzle, and the lifting platform is lowered in advance to the lower tank so that the surface of the platform is filled with water, then the platform is raised to receive the slurry sprayed by the nozzle, and then the platform is lowered to make the slurry All the materials are immersed in water, and the above process is repeated until the solidified part of the desired shape is obtained on the lifting platform, and the printing and solidification are completed at the same time, and the printing of the required sample is finally completed.

Example 3

A water curing 3D printing method includes the following steps:

(1) 37g of tricalcium silicate, 5g of calcium hydroxide, 3g of tetracalcium phosphate, 5g of calcium hydrogen phosphate, 4g of hydroxyapatite, 8g of hydroxybutyl chitosan, 5g of tantalum pentoxide and Mix 5 g of zirconium dioxide, dissolve in 28 g of water-soluble silicone oil, and perform ball milling and mixing in a ball mill for 12 hours to obtain Portland cement slurry.

(2) Pump the aforementioned Portland cement slurry into the barrel through a pressure pump, and pump water into the tank at the same time. A round nozzle is selected and the nozzle opening is controlled to 3mm. At the same time, the computer and the controller are operated to keep the air pump pressure at The required pressure is used to control the spraying speed of the Portland cement slurry, and then pressurized by the air pump to extrude the Portland cement slurry from the nozzle, and the lifting platform is lowered in advance to the lower tank so that the surface of the platform is flooded with water. Then the rising platform accepts the slurry ejected by the nozzle, and then the lower platform so that the slurry is completely immersed in water, repeat the above process until the lifting platform is solidified and formed to obtain a cured part of the desired shape, and the printing and curing are completed at the same time, and the required sample is finally completed Pieces of printing.

Claims

A water-curing 3D printing method, which is characterized in that: using water-curing materials or slurry doped with water-curing materials as raw materials, filling the raw materials into a 3D printer barrel, using three-dimensional drawing software to design and draw a pre-printed physical model, Control the 3D printer to squeeze out the material in the barrel and solidify with water to prepare the entity.
The water-curing 3D printing method according to claim 1, wherein the water-curing material is one of monomolecular polyurethane materials, silicate materials, aluminate materials, and water-based high molecular polymers. Many kinds.
The water-curing 3D printing method according to claim 2, wherein the preparation method of the monomolecular polyurethane material is:

(1) Add polyethylene glycol and KOH to the reaction flask, dehydrate under the oil bath with a vacuum degree of 0.10-0.11MPa and a temperature of 100-102℃, and cool down to 68-70℃; vacuum and nitrogen replacement reaction Bottle, to remove the air in the reaction flask; keep the temperature unchanged, slowly add propylene oxide dropwise under the protection of nitrogen, and continue the reaction until there is no reflux phenomenon after the dropwise addition is complete, and cool to room temperature to obtain crude polyol ；

(2) Add dichloromethane to the crude polyol obtained in step (1), use a vacuum filtration device, replace the filter paper with diatomaceous earth to remove KOH, adjust the pH to 5±0.2, and add a desiccant calcium chloride to proceed. Concentrate to obtain polyol;

(3) Add the polyol obtained in step (2) to the reaction flask, and under the condition of raising the temperature to 48-50°C, add dibutyltin dilaurate catalyst and diphenylmethane diisocyanate, and react for 1.4-1.6h, Then add antioxidants and ultraviolet absorbers, heat preservation reaction for 1-1.1h, reduce the temperature to room temperature, add methyl ethyl ketone, and obtain the polyurethane prepolymer whose end group is -NCO group;

(4) Mixing the polyurethane prepolymer obtained in step (3) with water to prepare a hydrophilic one-component water-curable polyurethane.
The water curing 3D printing method according to claim 3, wherein the relative molecular mass of polyethylene glycol is 1000; polyethylene glycol, KOH, propylene oxide, dibutyltin dilaurate catalyst and diphenylmethane The mass ratio of isocyanate is 40:0.40-0.42:3.0-3.02:0.20-0.21:0.60-0.62.
The water-cured 3D printing method according to claim 2, characterized in that: the preparation method of the silicate material is: 35-40 parts by weight of tricalcium silicate with a particle size of less than 10 μm, and 5-5.5 parts by weight of calcium hydroxide Parts, 3-3.5 parts by weight of tetracalcium phosphate, 5-5.5 parts by weight of calcium hydrogen phosphate, 4-4.5 parts by weight of hydroxyapatite, 8-8.5 parts by weight of hydroxybutyl chitosan, 5-5.5 parts by weight of tantalum pentoxide 5 parts by weight and 5-5.5 parts by weight of zirconium dioxide, dissolved in 27-29 parts by weight of water-soluble silicone oil, ball milling and mixing in a ball mill for 10-14 hours to obtain silicate materials.
The water-curing 3D printing method according to claim 2, wherein the water-based polymer is polyethersulfone; the slurry doped with water-curing material is: ethanol is used as a solvent, and nickel oxide and yttrium oxide The stabilized zirconia is mixed at a mass ratio of 70:30, ball milled at 240 rpm for 12-13 hours, and the ball milled slurry is dried and sieved to obtain anode powder; the above anode powder, polyethersulfone and n- The methylpyrrolidone is mechanically stirred in a mass ratio of 7.9-8.1:1.0:3.0-3.1 to obtain a slurry doped with water-curable materials.
The water curing 3D printing method according to any one of claims 1 to 6, characterized in that it comprises the following steps:

(1) Use a water-curing material as a slurry or stir and dissolve the water-cured material in a solvent to obtain a slurry, and fill the slurry into the 3D printer barrel;

(2) Use 3D drawing software to design and draw pre-printed physical models, slice and layer by 3D printing software, and use 3D printer to print in layers;

(3) The slurry in the 3D printer barrel is extruded from the material nozzle by pressure extrusion, and solidified on the forming platform to form a blank.
The water-curing 3D printing method according to claim 7, characterized in that: in step (1), the water-curing material is stirred and dissolved in a solvent, the solvent is methanol, ethanol or n-methylpyrrolidone, and the slurry is added at the same time A paste slurry is prepared from inorganic powder, and the inorganic powder is calcium hydroxide, tetracalcium phosphate or calcium hydrogen phosphate.
The water-cured 3D printing method according to claim 7, characterized in that: the raw material obtained in step (3) is subjected to post-processing to obtain the actual product; the post-processing includes heat treatment or dipping and coating of the device to obtain the entity, and the heat treatment is degreasing or sintering.
A device for realizing the water curing 3D printing method according to any one of claims 1 to 6, characterized in that it comprises a barrel (2), the barrel (2) is arranged on the housing (1), and the barrel (2) The nozzle (4) is connected through the conveying pipe (3), a lifting platform (5) is arranged under the nozzle (4), the lifting platform (5) is located inside the water tank (6), the nozzle (1) is connected with a sliding rod, and the sliding rod is connected with a driving device.