WO2017219618A1

WO2017219618A1 - Forming method

Info

Publication number: WO2017219618A1
Application number: PCT/CN2016/109047
Authority: WO
Inventors: 唐天
Original assignee: 唐天
Priority date: 2016-06-23
Filing date: 2016-12-08
Publication date: 2017-12-28
Also published as: CN106113498A

Abstract

A forming method. Visible light is output by a visible light digital image output device, visible light curable resin is used as a consumable, and layer-by-layer accumulation of visible light curable resin thin layers is controlled by a model platform (5) that can finely move. In the forming process, the visible light digital image output device (3) outputs a two-dimensional section visible light image (7), and visible light signals within the image range stimulate liquid visible light curable resin thin layers to make the visible light curable resin thin layers undergo a photochemical effect and then be cured; a new resin thin layer is formed by longitudinal movement of a model; the curing process is repeated and layer-by-layer curing and accumulation are conducted to form a three-dimensional curing model. The forming method does not depend on an ultraviolet source system, and features a wide optional range of light source devices, a stable and reliable system, a simple device and low manufacturing costs.

Description

One molding method

Technical field

The invention relates to the field of additive manufacturing technology, and in particular to a molding method.

Background technique

Additive manufacturing (also known as 3D printing) is a kind of rapid prototyping technology. It is based on digital model files and uses powder, liquid glue or ink, wire and other materials to construct objects by layer-by-layer printing. It can overcome the special structural obstacles that traditional machining cannot achieve, and can realize the rapid prototyping of components and the production of arbitrarily complex structural components. Existing additive manufacturing technologies are mainly divided into three categories: FDM melt extrusion, photocuring, and SLM/SLS laser selective powder sintering.

Existing light-curing 3D printing technologies include SLA laser scanning light curing and DLP digital micro-mirror projection light curing technology. The light source systems used are: laser scanning SLA (355/405nm laser) and UV-containing DLP projection (UVA). There are two types of light sources: 320nm-400nm; the corresponding resin consumables are UV-curable liquid resins, and the UV-curable liquid resins are photosensitive only to ultraviolet light (wavelengths of 405 nm and below). That is, the existing photo-curing three-dimensional printing technology relies heavily on an ultraviolet light source, and is limited to a DLP projection technology containing ultraviolet light and a complicated laser/galvanometer system, and has high requirements on a light source system. DLP digital micromirror technology is currently monopolized by Texas Instruments, and the laser devices and galvanometer scanning technology used by SLA are mainly owned by large foreign companies. Moreover, the three-dimensional printing method of DLP and SLA has high technical requirements, expensive equipment, complicated structure and poor stability. In addition, the models printed by the above techniques require complex post-processing steps, including the use of chemical dissolution. The agent cleans the surface and sends it to the UV curing chamber for long-time exposure and post-cure treatment.

Summary of the invention

In order to overcome the deficiencies of the prior art, the object of the present invention is to provide a molding method which does not need to rely on an ultraviolet light source system. The light source device has a wide range of options, the system is stable and reliable, the device is simplified, and the manufacturing cost is low.

The object of the invention is achieved by the following technical solutions:

A molding method comprising the following steps:

1) constructing a molding system, and providing a resin tank, a model platform, a driving component, a visible light digital image output device, a computer, and a hood in the molding work area;

The resin tank is an upper open structure for receiving a visible light curing resin;

The model platform is disposed above the resin tank for carrying a printed model;

The driving component is fixedly connected to the model platform, and the computer controls and drives the model platform to move in an up and down direction, that is, the model platform is driven to move upwards away from the resin groove or downwardly into the resin groove. ;

The visible light digital image output device is disposed above or below the resin tank, and is controlled by the computer to output visible light that cures the visible light curing resin;

The hood encloses the molding working area;

2) creating a two-dimensional cross-sectional view, the computer decomposing the three-dimensional modeling map of the preset model into a plurality of layers according to a preset direction and a preset slitting thickness, each layer being a two-dimensional cross-sectional view of the preset model;

3) moving the model platform, the driving component drives the model platform to move upward or downward, such that a visible light curing resin layer having a predetermined thickness is formed below or above the model platform, the predetermined thickness and the minute Cutting thickness is equal;

4) outputting visible light, the visible light digital image output device outputs visible light, the visible light acts on the visible light curing resin layer, and the visible light contour conforms to the two-dimensional cross-sectional view;

5) print molding, after the preset time, the visible light curing resin layer in the visible light irradiation region is solidified and adhered to the model platform to form a semi-finished curing model;

6) Repeat steps 3)-5) in sequence, and cumulatively print layer by layer to obtain a three-dimensional solidification model;

Wherein, in step 3), the driving component drives the model platform to move upward or downward, so that a visible light curing resin layer of a predetermined thickness is formed below or above the semi-finished curing model on the model platform;

In the step 4), the visible light-curable resin layer in the visible light irradiation region is cured and adhered to the semi-finished curing model.

Preferably, the method further comprises the following steps: step 7), after the removal of the three-dimensional solidification model from the model platform, the following operations are sequentially performed: surface cleaning, irradiation curing and drying.

Specifically, the specific operations of the surface cleaning, the irradiation curing and the drying are as follows: the surface of the three-dimensional model is washed with water of 25-50 ° C or an aqueous solution of detergent, and then immersed in a transparent container filled with water. And use sunlight or light for 0.5-2h, then Dry naturally. Dishwashing detergent is a general household detergent, such as branded detergents such as white, white cat, skillful hand, carved brand, and axe brand.

Preferably, the visible light curing resin has a curing response wavelength of 400-760 nm; correspondingly, the visible light digital image output device outputs visible light having a wavelength of 400-760 nm.

Preferably, the visible light digital image output device comprises an LCD display, a mobile phone display screen, a flat panel display, a television, a projector, a visible light laser imaging system, and a cathode ray tube display device.

Preferably, the hood is made of one or any combination of the following materials: plastic, wood and metal; the hood is red translucent, orange translucent, brown translucent and opaque. One or any combination.

Preferably, the slitting thickness is from 0.025 to 0.200 mm.

Preferably, the driving component is a support member for supporting the fixing of the model platform, a slider and a guide rail for guiding the movement of the support member, a stepping motor, and a synchronous coupling with the rotating shaft of the stepping motor. a drive screw for driving the support member, and a lead screw nut that is sleeved on the drive screw and fixedly connected to the support member.

Preferably, the resin groove is provided with a light transmissive bottom wall or a bottom film; the visible light digital image output device is disposed under the resin groove, and the visible light is irradiated from the bottom to the top through the transparent bottom wall The visible light-curing resin layer; when the printing is performed, the model platform moves upwards, so that a visible light curing with a predetermined thickness is formed between the mold platform or the semi-finished curing model and the transparent bottom wall or the bottom film a resin layer, the predetermined thickness being equal to the slit thickness.

Preferably, the visible light digital image output device is disposed above the resin groove, and visible light is irradiated onto the visible light curing resin layer from top to bottom; when the printing is performed, the model platform moves downward to make the model Forming the platform or the semi-finished curing model into the visible light curing resin, and forming a visible light curing resin layer of a predetermined thickness on the mold platform or the semi-finished curing model, the predetermined thickness being equal to the slitting thickness .

Compared with the prior art, the beneficial effects of the present invention are:

(1) The molding method provided by the present invention can select a digital display device as a light source system, and use visible light curing resin as a consumable material to realize three-dimensional printing. The light source system of the present invention does not require any type of light source system (for example, 405 nm wavelength ultraviolet DLP projection, or SLA with 355 nm or 405 nm wavelength laser galvanometer system) depending on the wavelength of ultraviolet light (405 nm and below), and is free from foreign DLP technology or laser/ Monopoly restrictions on galvanometer technology. Any existing mature digital display device, including projectors, monitors, and mobile device screens, can be selected in a wide range; and the current visible light source technology is mature, which makes the entire 3D printing system more stable and reliable, the device is more streamlined, and the manufacturing cost is lower. .

(2) The molding method provided by the present invention can adopt a large-scale digital image output system, so that the three-dimensional model has a larger molding size and a larger volume output per unit time.

(3) According to the molding method provided by the present invention, the hood can be made of a red translucent material, an orange translucent material, a brown translucent material or an opaque material, and can effectively shield the ambient illumination (daylight/indoor lighting) from having a wavelength of 400- The light wave of 630nm effectively avoids the phenomenon that the visible light curing resin in operation is deteriorated due to ambient light irradiation.

(4) The molding method provided by the present invention does not require complicated three-dimensional solid model The post-treatment exposure process has good mechanical strength, high molding precision, good surface quality, dry surface and no adhesive residue.

DRAWINGS

1 is a molding system used in a molding method according to Embodiment 1 of the present invention;

2 is a molding system used in a molding method according to Embodiment 2 of the present invention;

3 is a molding system used in a molding method according to Embodiment 3 of the present invention;

In the figure: 1, drive components; 2, resin tank; 3, visible light digital image output equipment; 4, hood; 5, model platform; 6, semi-finished solidification model; 7, two-dimensional cross-section visible light image.

detailed description

The present invention will be further described below in conjunction with the drawings and specific embodiments.

A molding method comprising the following steps:

1) constructing a molding system, providing a resin tank 2, a model platform 5, a drive assembly 1, a visible light digital image output device 3, a computer and a hood 4 in a molding work area;

The resin tank 2 is an upper open structure for receiving a visible light curing resin;

The model platform 5 is disposed above the resin tank 2 for carrying the printed model;

The driving assembly 1 is fixedly connected to the model platform 5, and is controlled by the computer to drive the model platform 5 to move in the up and down direction, that is, to drive the model platform 5 to move upwards away from the resin tank 2 or downwardly into the resin tank 2;

The visible light digital image output device 3 is disposed above or below the resin tank 2, Computer controls and outputs visible light that cures the visible light curing resin;

The hood 4 encloses the molding working area;

2) Create a two-dimensional sectional view, and input a preset three-dimensional modeling drawing by a computer, and decompose it into several layers according to a preset direction and a preset cutting thickness by a slicing algorithm to obtain a two-dimensional sectional view of a series of preset models;

3) moving the model platform 5, loading a certain amount of liquid visible light curing resin into the resin tank 2, and then driving the assembly 1 to move the model platform 5 upward or downward, so that a predetermined thickness is formed below or above the model platform 5. a visible light curing resin layer, the predetermined thickness being equal to the slitting thickness;

4) outputting visible light, the visible light digital image output device 3 outputs visible light, the visible light acts on the visible light curing resin layer, and the visible light contour conforms to the two-dimensional cross-sectional view;

5) print molding, in the visible light irradiation region, the visible light curing resin layer after a predetermined exposure time, the liquid is converted into a solid state by photochemical reaction, and adhered to the model platform 5 to form a semi-finished solidification model 6; The portion of the visible light curing resin in the resin bath 2 is still in a liquid state; after the mold platform 5 drives the semi-finished solidification model 6 to move, the liquid visible light curing resin is redistributed to fill the resin tank 2;

Wherein, in step 3), the driving component 1 drives the model platform 5 to move upward or downward, so that a predetermined thickness of the visible light curing resin layer is formed below or above the semi-finished curing model 6 on the model platform 5;

In the step 4), the visible light-curable resin layer in the visible light irradiation region is cured and adhered to the semi-finished cured mold 6.

Example 1

As shown in FIG. 1, the visible light digital image output device 3 is preferably a 7-inch LCD liquid crystal screen, TFT type, display area size is 142 x 107 mm, brightness is 1000 cd/m ² , contrast is 800:1, resolution is 800 x 600, and pixel size is 0.18x0.18mm. The two-dimensional cross-sectional visible light image 7 is a white/blue/cyan pattern in the visible light range output by the visible light digital image output device 3, which is a mirror image of a two-dimensional cross-sectional view of the corresponding layer thickness. The resin bath 2 is provided with a visible light curable resin, and the bottom wall thereof is a light transmissive film which is in close contact with the surface of the visible light digital image output apparatus 3. The model platform 5 is connected to a drive assembly 1 comprising a stepper motor/slider/rail, the total stroke of the drive assembly 1 being 200 mm, preferably 0.10 mm per step height.

In the molding process, the height of the semi-finished curing model 6 is determined by the driving unit 1, and the lower end of the semi-finished curing mold 6 is immersed in the resin tank 2, and the lower portion thereof is a thin layer of visible light-curing resin, and the layer thickness is preferably 0.10 mm. The visible light digital image output device 3 is controlled by a computer to output visible light, and the output visible light contour is consistent with the current two-dimensional cross-sectional visible light image 7, and the visible light is transmitted through the transparent film at the bottom of the resin tank 2 on the thin layer of the visible light curing resin. . After a certain exposure time (about 20-30 seconds), the thin layer of the visible light curing resin irradiated by visible light is chemically polymerized and solidified to form a new solid thin layer, and the shape of the solid thin layer is determined by the two-dimensional cross-sectional visible light image 7 The cured thin layer is attached to the lower end of the semi-finished curing model 6. In addition to the light field of the two-dimensional cross-section visible image 7, the resin The other visible light curable resin in the tank 2 is not exposed to light and remains in a liquid state. Subsequently, the model platform 5 drives the semi-finished solidification model 6 to rise, separating the newly formed solid thin layer from the bottom wall of the resin tank 2. At the same time, the liquid visible light curable resin in the resin tank 2 flows freely, and a new resin thin layer is newly formed at the bottom of the semi-finished solidification mold 6, and the layer thickness of the drive unit 1 is controlled to 0.10 mm. At this time, the visible light digital image output device 3 gives a new layer of the two-dimensional cross-section visible light image 7, and the liquid visible light curing resin in the resin bath 2 is selectively photocured. Repeat the above steps and accumulate layer by layer to complete the solidification molding of the entire 3D model.

In the molding process, the accuracy in the xy plane is 0.18 mm, the z-axis accuracy is 0.10 mm, the printing speed is about 15 mm/h, and the print output rate is up to 100 ml/h.

Example 2

As shown in FIG. 2, the visible light digital image output device 3 is preferably a 42-inch LCD screen with a display area size of 930x522 mm, a brightness of 800 cd/m ² , a contrast ratio of 1200:1, a resolution of 3840×2160, and a pixel size of 0.24×0. 24mm. The two-dimensional cross-section visible light image 7 is an array of white/blue/cyan patterns output by the liquid crystal panel, which is a mirror image of a two-dimensional cross-sectional view of the corresponding layer thickness. As shown in FIG. 2, if the size of the preset three-dimensional model is small, two to hundreds of identical model copies or different model combinations can be arranged in the display range of the visible light digital image output device 3, and they are evenly arranged in an array. The resin bath 2 is provided with a visible light curable resin, and the bottom wall thereof is a light transmissive film which is in close contact with the surface of the visible light digital image output apparatus 3. The model platform 5 preferably has a size of 900 x 500 mm and is connected by a drive unit 1 equipped with a large slider rail system. The total stroke of the drive unit 1 is 700 mm, and the step height is preferably 0.15 mm per step.

In the molding process, the height of the semi-finished curing model 6 is determined by the driving unit 1, and the lower end of the semi-finished curing mold 6 is immersed in the resin tank 2, and the lower portion thereof is a thin layer of visible light-curing resin, and the layer thickness is preferably 0.15 mm. The visible light digital image output device 3 is controlled by a computer to output visible light, and the output visible light contour conforms to the current two-dimensional cross-section visible light image 7, and the visible light passes through the transparent film at the bottom of the resin tank 2, and is irradiated on the thin layer of the visible light curing resin. on. After a certain exposure time (about 40-60 seconds), the thin layer of visible light-curing resin irradiated by visible light is chemically polymerized and solidified to form a new solid thin layer, and the shape of the solid thin layer is determined by the two-dimensional cross-sectional visible light image 7 The cured thin layer is attached to the lower end of the semi-finished curing model 6. In addition to the light field of the two-dimensional cross-section visible light image 7, the other visible light-curing resin in the resin bath 2 is not irradiated with light, and remains in a liquid state. Subsequently, the model platform 5 drives the semi-finished solidification model 6 to rise, separating the newly formed solid thin layer from the light-transmissive film of the resin tank 2. At the same time, the liquid visible light curable resin in the resin tank 2 flows freely, and a new resin thin layer is newly formed at the bottom of the semi-finished solidification model 6, and the layer thickness of the drive unit 1 is controlled to 0.15 mm. At this time, the visible light digital image output device 3 gives a new layer of the two-dimensional cross-section visible light image 7, and the liquid visible light curing resin in the resin bath 2 is selectively photocured. Repeat the above steps and accumulate layer by layer to complete the solidification molding of the entire 3D model.

In the molding process, the accuracy in the xy plane is 0.24 mm, the z-axis accuracy is 0.15 mm, the printing speed is about 12 mm/h, and the print output rate is up to 400 ml/h.

Example 3

As shown in FIG. 3, the visible light digital image output device 3 is preferably a high-definition high-brightness projector and its accompanying optical lens set, with a projection distance of 250 mm, a projection area size of 192 x 108 mm, a projector brightness of 10,000 ANSI lumens, and a contrast ratio of 1000:1. The resolution is 3840x2160 and the pixel size is 0.05x0.05mm. The two-dimensional cross-section visible light image 7 is an array of white/blue/cyan patterns output by the liquid crystal panel, which is a mirror image of a two-dimensional cross-sectional view of the corresponding layer thickness. The resin tank 2 is filled with a liquid visible light curing resin, and the visible light curing resin has a depth of more than 150 mm. The model platform 5 is of a lower suspension type, and the model platform 5 is immersed in the resin tank 2, the platform size is 160x130 mm, the total stroke is 150 mm, and the step height is preferably 0.05 mm.

In the molding process, the height of the semi-finished curing model 6 is determined by the driving unit 1, and the semi-finished curing model 6 is immersed in the resin tank 2. The top end of the semi-finished curing model 6 is a thin resin layer, and the layer thickness is preferably 0.05 mm. The visible light digital image output device 3 is controlled by a computer to project a current two-dimensional cross-sectional visible light image 7 on the surface of the resin thin layer. The thin layer of resin irradiated by visible light is chemically polymerized and solidified after a certain exposure time (about 1-2 seconds) to form a new solid thin layer, and the shape is determined by the two-dimensional cross-sectional visible light image 7; the cured thin layer is adhered At the top of the semi-finished curing model 6. Outside the light field of the two-dimensional cross-section visible light image 7, the thin resin layer is not illuminated by light and remains in a liquid state. Subsequently, the model platform 5 drives the semi-finished solidification model 6 to fall, immersed under the resin liquid surface. The top of the semi-finished curing model 6 reforms a new thin layer of resin, controlled by the drive assembly 1 to a layer thickness of 0.05 mm. At this time, the optical digital image output device 3 is given a new one-dimensional two-dimensional visible light image 7, and the liquid visible light curing resin in the resin tank 2 is selectively photocured. Repeat the above steps and accumulate layer by layer to complete the solidification molding of the entire 3D model.

In the molding process, the precision in the xy plane is 0.05 mm, the z-axis accuracy is 0.05 mm, the printing speed is about 100 mm/h, and the print output rate is up to 1000 ml/h.

Various other changes and modifications may be made by those skilled in the art in light of the above-described technical solutions and concepts, and all such changes and modifications are intended to fall within the scope of the appended claims.

Claims

A molding method, comprising the steps of:

1) constructing a molding system, and providing a resin tank, a model platform, a driving component, a visible light digital image output device, a computer, and a hood in the molding work area;

The resin tank is an upper open structure for receiving a visible light curing resin;

The model platform is disposed above the resin tank for carrying a printed model;

The driving component is fixedly connected to the model platform, and the computer controls and drives the model platform to move in an up and down direction, that is, the model platform is driven to move upwards away from the resin groove or downwardly into the resin groove. ;

The visible light digital image output device is disposed above or below the resin tank, and is controlled by the computer to output visible light that cures the visible light curing resin;

The hood encloses the molding working area;

2) creating a two-dimensional cross-sectional view, the computer decomposing the three-dimensional modeling map of the preset model into a plurality of layers according to a preset direction and a preset slitting thickness, each layer being a two-dimensional cross-sectional view of the preset model;

3) moving the model platform, the driving component drives the model platform to move upward or downward, such that a visible light curing resin layer having a predetermined thickness is formed below or above the model platform, the predetermined thickness and the minute Cutting thickness is equal;

4) outputting visible light, the visible light digital image output device outputs visible light, the visible light acts on the visible light curing resin layer, and the visible light contour conforms to the two-dimensional cross-sectional view;

5) Printing and molding, after a preset time, in the visible light irradiation area The visible light curing resin layer is cured and adhered to the model platform to form a semi-finished curing model;

6) Repeat steps 3)-5) in sequence, and cumulatively print layer by layer to obtain a three-dimensional solidification model;

Wherein, in step 3), the driving component drives the model platform to move upward or downward, so that a visible light curing resin layer of a predetermined thickness is formed below or above the semi-finished curing model on the model platform;

In the step 4), the visible light-curable resin layer in the visible light irradiation region is cured and adhered to the semi-finished curing model.
The molding method according to claim 1, further comprising a step 7), subsequent processing, after removing the three-dimensional solidification model from the model platform, sequentially performing the following operations: surface cleaning, irradiation curing, and dry.
The molding method according to claim 2, wherein the surface cleaning, the irradiation curing, and the drying are performed as follows: the surface of the three-dimensional model is washed with water of 25-50 ° C or an aqueous solution of detergent, and then placed Soak in a clear container filled with water and illuminate with sunlight or light for 0.5-2 hours, then dry naturally.
The molding method according to claim 1, wherein the visible light curing resin has a curing response wavelength of 400 to 760 nm; correspondingly, the visible light digital image output device outputs visible light having a wavelength of 400 to 760 nm.
The molding method according to claim 1, wherein said visible light digital image output device comprises an LCD display, a mobile phone display, a flat panel display, a television, a projector, a visible light laser imaging system, and a cathode ray tube display device.
The molding method according to claim 1, wherein the hood is made of one or any combination of the following materials: plastic, wood, and metal; the hood is red translucent, orange One or any combination of translucent, brown translucent, and opaque.
The molding method according to claim 1, wherein the slitting thickness is from 0.025 to 0.200 mm.
The molding method according to claim 1, wherein the driving assembly is a support member for supporting the fixing of the mold platform, a slider and a guide rail for guiding movement of the support member, a stepping motor, a drive screw synchronously coupled with the rotating shaft of the stepping motor and configured to drive the support member, and a lead screw nut that is coupled to the drive screw and fixedly coupled to the support member.
The molding method according to claim 1, wherein the resin groove is provided with a light transmissive bottom wall or a bottom film; the visible light digital image output device is disposed below the resin groove, and the visible light is from the bottom to the bottom Irradiating on the visible light curing resin layer through the light transmissive bottom wall; when the printing is performed, the model platform moves upwards, so that the model platform or the semi-finished curing model and the transparent bottom wall or bottom A visible light curing resin layer having a predetermined thickness is formed between the films, and the predetermined thickness is equal to the slitting thickness.
The molding method according to claim 1, wherein the visible light digital image output device is disposed above the resin groove, and visible light is irradiated onto the visible light curing resin layer from top to bottom; The model platform moves downward such that the model platform or the semi-finished curing model is immersed in the visible light curing resin, and a visible light of a predetermined thickness is formed on the model platform or the semi-finished curing model The resin layer is cured, and the predetermined thickness is equal to the slit thickness.