CN113478822B

CN113478822B - Three-dimensional object printing method and device, storage medium and computer device

Info

Publication number: CN113478822B
Application number: CN202110729735.8A
Authority: CN
Inventors: 吕如松; 黄雅滢; 蒋韦
Original assignee: Zhuhai Sailner 3D Technology Co Ltd
Current assignee: Zhuhai Sailner 3D Technology Co Ltd
Priority date: 2021-06-29
Filing date: 2021-06-29
Publication date: 2023-06-06
Anticipated expiration: 2041-06-29
Also published as: CN113478822A

Abstract

The application provides a three-dimensional object printing method and device, a storage medium and computer equipment, wherein the method comprises the steps of providing powder material to form a powder material layer with a first height; applying a liquid material to the powder material layer according to the layer printing data to form a molding layer, wherein the molding layer comprises a patterned area and a non-patterned area, and the patterned area has a second height, the second height is smaller than the first height, and the second height is a preset layer thickness; the steps of forming the powder material layer to forming the molding layer are repeatedly performed, so that the obtained patterned areas of the plurality of molding layers are layered one by one to form the three-dimensional object. According to the three-dimensional object printing method and device, the storage medium and the computer equipment, the problem of layer shrinkage caused by the reaction of the powder material and the liquid material can be compensated in advance, so that the height of the patterned area of the formed forming layer meets the preset layer thickness, and the forming precision of the three-dimensional object is improved.

Description

Three-dimensional object printing method and device, storage medium and computer device

Technical Field

The present disclosure relates to the field of three-dimensional object forming technologies, and in particular, to a three-dimensional object printing method and apparatus, a storage medium, and a computer apparatus.

Background

The main process of the three-dimensional object forming technology is to obtain a digital model of a three-dimensional object, slice and layer the digital model, process and convert data of each slice layer to obtain printing data of each slice layer, and print the three-dimensional object layer by layer and stack the printing data according to the printing data of the slice layers by a printing device.

In the process of forming a print layer by selectively spraying a liquid material on a powder layer based on the existing three-dimensional printing technology combining powder and inkjet printing, the liquid material dissolves or melts the powder material due to interaction between the liquid material and the powder material, and/or air overflows between the powder materials when energy is supplied to the powder material layer, etc., all cause an increase in bulk density of the powder material, thereby causing collapse of a molding layer with respect to the powder material layer, making a height of the molding layer smaller than a designated layer height, and thus causing a problem of low molding accuracy of a three-dimensional object finally formed.

Disclosure of Invention

The embodiment of the application provides a three-dimensional object printing method and device, a storage medium and computer equipment, which can compensate the layer shrinkage problem caused by the reaction of a powder material and a liquid material in advance, so that the height of a patterning area of a formed forming layer meets the preset layer thickness, and the forming precision of the three-dimensional object is improved.

In a first aspect, embodiments of the present application provide a three-dimensional object printing method, including:

providing a powder material to form a layer of powder material having a first height;

applying a liquid material to the powder material layer according to layer print data to form a shaping layer, the shaping layer comprising patterned areas and non-patterned areas, the patterned areas having a second height, wherein the second height is less than the first height and the second height is a preset layer thickness;

repeating the steps of forming the powder material layer to forming the molding layer, so that the obtained patterned areas of the plurality of molding layers are layered one by one to form a three-dimensional object.

With reference to the first aspect, in a possible implementation manner, the repeatedly performing the steps from forming the powder material layer to forming the shaping layer includes:

providing a powder material to form an n+1th powder material layer on the N-th molding layer, wherein the n+1th powder material layer has the first height, the first height is based on a patterned area of the N-th molding layer, and N is a natural number greater than or equal to 1;

applying a liquid material to the n+1th powder material layer according to the layer print data to form an n+1th molding layer, the patterned area of the n+1th molding layer having the second height;

And (3) confirming whether the (n+1) th molding layer is the last layer, if not, repeating the steps from forming the powder material layer to forming the molding layer, and enabling the obtained patterning areas of the plurality of molding layers to be stacked one by one to form a three-dimensional object.

With reference to the first aspect, in a possible implementation, the first height is obtained according to the second height and the shrinkage of the powder material layer.

With reference to the first aspect, in a possible embodiment, the powder material layer shrinkage rate r= (R _{Front part} -R _{Rear part (S)} )/R _{Front part} *100, wherein R is _{Front part} Refers to the thickness of the powder material layer before shrinkage, R _{Rear part (S)} Refers to the thickness of the powder material layer after shrinkage.

With reference to the first aspect, in one possible embodiment, the powder material is selected from at least one of polystyrene, polyvinyl chloride, polyacrylonitrile, acrylonitrile-styrene-acrylate copolymer, polyamide, polyester, polyurethane, polylactic acid, poly (meth) acrylate, poly (meth) methyl acrylate, polyvinyl fluoride, chlorinated polyolefin, polyvinyl alcohol containing hydroxyl groups, cellulose, modified cellulose.

With reference to the first aspect, in a possible implementation manner, the preset layer thickness is a constant value.

With reference to the first aspect, in a possible implementation manner, the method meets at least one of the following features:

a. the liquid material dissolves at least a portion of the powder material;

b. the liquid material undergoes thermal polymerization and/or photopolymerization;

c. the liquid material and the powder material are subjected to polymerization reaction;

d. the liquid material melts at least a portion of the powder material.

With reference to the first aspect, in a possible implementation, before the applying of the liquid material on the powder material layer according to the layer print data, the method further comprises:

preheating the layer of powder material.

With reference to the first aspect, in a possible implementation, after the applying of the liquid material onto the powder material layer according to the layer print data, the method further comprises:

providing energy to the layer of powder material after application of the liquid material to form the shaping layer.

With reference to the first aspect, in a possible implementation manner, the energy includes at least one of radiant energy and thermal energy.

In a second aspect, the present application provides a three-dimensional object printing apparatus for implementing the three-dimensional object printing method according to the first aspect, the printing apparatus including:

A powder supply part for supplying a powder material to form a powder material layer;

a forming platform for carrying the powder material layer;

a material dispenser for applying a liquid material to the powder material layer according to layer print data to form a shaping layer, the shaping layer comprising patterned and non-patterned regions, the patterned regions having a second height, wherein the second height is less than the first height and the second height is a preset layer thickness;

and a controller for controlling the powder supply part and the material dispenser to repeatedly perform the steps of forming the powder material layer to forming the molding layer, so that the obtained patterned areas of the plurality of molding layers are stacked one by one to form a three-dimensional object.

With reference to the second aspect, in a possible implementation manner, the printing apparatus further includes:

and an energy supply device for supplying energy to the powder material layer to which the liquid material is applied, so as to form a molded layer of the three-dimensional object.

With reference to the second aspect, in a possible implementation manner, the printing apparatus further includes a lifting mechanism, where the lifting mechanism is connected to the forming platform, and drives the forming platform to lift or descend in a vertical direction.

With reference to the second aspect, in a possible implementation manner, the printing apparatus further comprises a preheating component and/or a heating component, the preheating component being used for preheating the powder material layer; the heating member is for heating the liquid material.

With reference to the second aspect, in a possible embodiment, the energy supply device, the preheating part and the heating part may be at least one selected from an ultraviolet lamp, an infrared lamp, a microwave emitter, a heating wire, a heating sheet, and a heating plate, respectively.

With reference to the second aspect, in a possible implementation manner, the printing apparatus further includes a temperature monitor for monitoring a temperature of the powder material layer.

In a third aspect, the present application provides a non-transitory computer readable storage medium, where the storage medium includes a stored program, and when the program runs, controls a device in which the storage medium is located to execute the three-dimensional object printing method according to the first aspect.

In a fourth aspect, the present application provides a computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, the processor performing the three-dimensional object printing method of the first aspect.

The technical scheme of the application has the following beneficial effects:

the three-dimensional object printing method, the three-dimensional object printing device, the storage medium and the computer device provided by the embodiment of the application are characterized in that powder materials are provided to form a powder material layer with a first height on a forming platform or a previous forming layer, then liquid materials are applied to the powder material layer according to layer printing data to form a forming layer, the forming layer comprises a patterned area and a non-patterned area, and the patterned area is provided with a second height, wherein the second height is smaller than the first height; that is, by providing an excessive amount of powder material in each powder material layer, the problem of layer shrinkage caused by the reaction of the powder material and the liquid material is compensated in advance, so that the patterned region of the formed molding layer can satisfy a predetermined layer thickness (i.e., a predetermined second height) although the height of the formed molding layer is smaller than that of the powder layer, thereby improving the molding accuracy of the three-dimensional object.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the application.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive effort to a person skilled in the art.

Fig. 1 is a schematic flow chart of a three-dimensional object printing method according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a three-dimensional object printing apparatus according to an embodiment of the present application;

FIG. 3 is a schematic flow chart of a three-dimensional object printing method according to another embodiment of the present application;

FIG. 4 is a schematic structural diagram of a three-dimensional object printing process according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a three-dimensional object printing process according to an embodiment of the present application;

FIG. 6 is a schematic structural diagram of a storage medium provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram of a computer device provided in an embodiment of the present application.

Detailed Description

For a better understanding of the technical solutions of the present application, embodiments of the present application are described in detail below with reference to the accompanying drawings.

It should be understood that the described embodiments are merely some, but not all, of the embodiments of the present application. All other embodiments, based on the embodiments herein, which would be apparent to one of ordinary skill in the art without making any inventive effort, are intended to be within the scope of the present application.

The terminology used in the embodiments of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this application and the appended claims, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be understood that the term "and/or" as used herein is merely one relationship describing the association of the associated objects, meaning that there may be three relationships, e.g., a and/or B, may represent: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

Fig. 1 is a flowchart of a three-dimensional object printing method provided in this embodiment, referring to fig. 1, the three-dimensional object printing method provided in this embodiment includes the following steps:

step S10, providing a powder material to form a powder material layer with a first height;

step S20, applying a liquid material onto the powder material layer according to layer printing data to form a molding layer, wherein the molding layer comprises a patterned area and a non-patterned area, and the patterned area has a second height, wherein the second height is smaller than the first height, and the second height is a preset layer thickness;

step S30, repeating the steps of forming the powder material layer to forming the molding layer, so that the obtained patterned areas of the plurality of molding layers are layered one by one to form the three-dimensional object.

In this aspect, a layer of powder material having a first height is formed on a forming platen or a previous forming layer by providing the powder material, and then applying a liquid material on the layer of powder material according to layer print data to form a forming layer having a second height, wherein the second height is less than the first height; that is, by providing an excessive amount of powder material in each powder material layer, the problem of layer shrinkage caused by the reaction of the powder material and the liquid material is compensated in advance, so that the patterned region of the formed molding layer can satisfy a predetermined layer thickness (i.e., a predetermined second height) although the height of the formed molding layer is smaller than that of the powder layer, thereby improving the molding accuracy of the three-dimensional object.

In order to avoid that the shaping layer height deviates from the preset layer thickness, in the present embodiment, the first height H1 may be obtained according to the second height H2 and the powder material layer shrinkage.

Specifically, the shrinkage rate r= (R) _{Front part} -R _{Rear part (S)} )/R _{Front part} *100, wherein R is _{Front part} Refers to the thickness of the powder material layer before shrinkage, R _{Rear part (S)} Refers to the thickness of the powder material layer after shrinkage. In the present embodiment, the ratio of the decrease in the height of the molding layer relative to the height of the powder material layer is taken as the powder material layer shrinkage, and then, the first height h1=the second height H2/(1-R), since the second height H2 is equal to the preset layer thickness, the thickness of the powder material layer of the molding layer to be printed can be calculated from the powder material layer shrinkage.

The powder material may be a single material or a mixed material, and is not limited herein. It will be appreciated that the shrinkage of the powder material layer is determined by the characteristics of the powder material and the liquid material, and that the shrinkage of the powder material layer can be obtained from a plurality of test results under the same environmental conditions.

In the process of printing the three-dimensional object, the preset layer thickness of each molding layer to be printed can be a constant value or a non-constant value, for example, the layer thickness of the molding layers is gradually decreased along with the superposition of the molding layers, and the layer thickness of the molding layers can be sequentially increased along with the superposition of the molding layers. In general, in order to reduce the amount of calculation and improve the printing efficiency, the preset layer thickness of each molding layer is a constant value. Then the first height H1 of each layer of powder material is also constant at a constant second height H2.

When the thickness of the molding layer to be printed is not constant, the preset thickness of the molding layer to be printed at present can be obtained according to the layer printing data, and the thickness (namely the first height) of the powder material layer required by the molding layer to be printed at present is calculated through the shrinkage rate of the powder material layer and the preset thickness.

As an alternative to the present application, the powder material is a material particle in powder form. The powder material includes powdery particulate material, powder-based material, and particulate material. The powder material may be selected from a powder metal material, a powder synthetic material, a powder ceramic material, a powder glass material, a powder resin material, a powder polymer material, and the like, without limitation. In this embodiment, the powder material may not undergo polymerization reaction with the liquid material, and the powder material itself may not undergo polymerization reaction; the powder material can also be polymerized with the liquid material, and the powder material can also be polymerized and can be selected according to actual requirements.

Optionally, the powder material is selected from at least one of Polystyrene (PS), polyvinyl chloride (PVC), polyacrylonitrile, acrylonitrile-styrene-acrylate copolymer (ASA), polyamide (PA), polyester, polyurethane (PU), polylactic acid, poly (meth) acrylate, poly (meth) methyl acrylate, polyvinyl fluoride, chlorinated polyolefin, polyvinyl alcohol (PVA) containing hydroxyl groups, cellulose, modified cellulose.

The melting point or melting temperature of the powder material in this embodiment may be 60 deg.c to 300 deg.c. The powder material provided in this embodiment can satisfy the use requirement when forming the powder layer, the gap formed between the powder materials can be filled with the applied liquid material and the liquid material, and the applied liquid material and the liquid material can wet the surface of the powder material.

Alternatively, the particle shape of the powder material is not particularly limited, and the powder material may be spherical, dendritic, plate-like, disk-like, needle-like, rod-like, or the like in this embodiment according to the difference in process of manufacturing the powder material.

Further, the average particle diameter of the powder material is 1 μm to 400. Mu.m, for example, 1 μm, 5 μm, 10 μm, 30 μm, 50 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm or 400 μm, and other values within the above range are also possible. The particle size of the powder material is too small, so that the liquid material is difficult to permeate to the bottom of the current powder material layer in a short time, and the contact of the liquid material with the powder material is not facilitated. The particle size of the powder material is too large, and gaps among powder particles are too large, so that the molding accuracy of the three-dimensional object can be affected. The average particle diameter of the powder material is preferably 30 μm to 200. Mu.m. The particle gap in the powder material is approximately 5nm to 100. Mu.m, and may be, for example, 5nm, 10nm, 100nm, 250nm, 500nm, 1. Mu.m, 5. Mu.m, 10. Mu.m, 25. Mu.m, 50. Mu.m, 75. Mu.m, or 100. Mu.m, without limitation. The particle gap of the powder material in this embodiment is in the range of 5nm to 100 μm, and when the liquid material is selectively applied to the powder material layer, the liquid material can rapidly penetrate into the powder material layer through the gap and remain partially on the surface layer, thereby wetting the surface of the powder material in the selected region.

Alternatively, the thickness of the powder material layer is 10 μm to 500 μm, and may be, for example, 10 μm, 25 μm, 50 μm, 75 μm, 100 μm, 125 μm, 150 μm, 200 μm, 300 μm, 400 μm or 500 μm. The thickness of the powder material layer is preferably 50 μm to 150 μm. It will be appreciated that when the thickness of the powder material layer is thin, objects with higher resolution can be formed, but the time taken to manufacture the objects is greatly lengthened and the manufacturing cost is increased; when the thickness of the powder material layer is thick, the time for the liquid material to infiltrate the powder material is prolonged, and the resolution of the object to be manufactured is lowered, which is difficult to be expected.

In this application, the powder material may further include a filler, where the filler is used to improve the mechanical strength of the three-dimensional object, and the filler may specifically be at least one of graphene, carbon nanotubes, glass fiber, and kaolin, which is not limited in this embodiment. The mass ratio of the filler in the powder material is 0% to 5%, specifically, 0%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, etc., but it is needless to say that the filler may be other values within the above range, and the present invention is not limited thereto. The filler cannot change in volume in the forming process, and when the mass ratio of the filler is higher, the rigidity and tensile strength of the formed three-dimensional object are stronger, but the toughness is reduced; when the mass ratio of the filler is too high, the formed three-dimensional object is easy to become brittle and easy to damage. It can be appreciated that by adding a proper amount of filler to the powder material, the toughness of the three-dimensional object can be ensured and the mechanical strength of the three-dimensional object can be improved.

In this application, the powder material may further include a flow aid, which is used to improve flowability of the powder material, and the flow aid may specifically be silica, talc, or the like, and is not limited in this embodiment. The flow aid may be present in the powder material in an amount of 0% to 5% by mass, specifically 0%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5% or 5%, or the like, but may be present in other amounts within the above range, and is not limited thereto. It will be appreciated that the flow aid will not undergo a volume change during the forming process and that a suitable amount of flow aid may be advantageous to improve the flowability of the powder material, but that when the flow aid mass ratio is too high, the original performance characteristics of the powder material will be altered.

In one embodiment, the liquid material dissolves at least part of the powder material, and it is noted that dissolution in this example refers to all possible cases except complete insolubilization. For example, when 1g of powder material is placed in 100g of active ingredient, at least 1% of the powder material is dissolved. Preferably, the liquid material completely dissolves the powder material. The dissolution is not limited to normal temperature, and the liquid material can be realized under the condition of heating and/or stirring to dissolve the powder material; the dissolution is not limited to one dissolution but may be staged in stages, such as slow dissolution when the liquid material is contacted with the powder material, and the powder material may be heated to increase the dissolution rate.

In another embodiment, the liquid material undergoes thermal and/or photopolymerization and/or the liquid material undergoes polymerization with the powder material. The present embodiment is not limited to the liquid material as long as it can finally cure and mold the powder material sprayed with the liquid material.

In one embodiment, the liquid material may contain an energy absorber that converts energy into thermal energy upon absorption of the supplied energy, thereby melt-shaping the powder material in contact therewith. In another embodiment, the liquid material is a photocurable material, the liquid material comprises a photocurable component, and the photocurable component is capable of dissolving the powder material, and the photoinitiator causes polymerization of the photocurable component upon irradiation with energy such as radiant energy to entangle and cure the dissolved powder molecules into a shape. In another embodiment, the liquid material is a thermally curable material, the liquid material comprising a thermally curable component, and the thermally curable component is initiated by a thermal initiator to polymerize upon the application of energy, such as thermal energy, to form a polymer that encapsulates the powder material. In another embodiment, the liquid material has an active component that reacts with the powder material and the initiator initiates polymerization of the liquid material with the powder material upon the application of energy.

In an embodiment, the liquid material melts at least part of the powder material, in particular, it may be that the temperature of the heated liquid material is higher than the melting point of at least part of the powder material, so that the liquid material applied on the powder material is able to melt the powder material, which after cooling forms a shaping layer.

Further, the liquid material further comprises an auxiliary agent, in particular selected from the group consisting of an initiator, a leveling agent, a defoaming agent, a surfactant, and the like.

The initiator is used for initiating the liquid material to react, and the initiator can be a photoinitiator, a free radical initiator, an anionic initiator, a cationic initiator and the like according to the type of the liquid material. The leveling agent is used to improve the fluidity of the liquid material and the wettability to the powder material, and at the same time, adjust the surface tension of the liquid material so that it can be printed normally, without limitation in this embodiment. The defoamer is mainly used for preventing foaming of the liquid material, and can be, for example, silicone defoamer, polyether defoamer, fatty acid ester defoamer and the like. Surfactants are mainly used to control the wettability, permeability and surface tension of a liquid material to a powder material, and may be, for example, anionic surfactants, nonionic surfactants and amphoteric surfactants.

The liquid material may also include a colorant, which may be a dye or pigment, when included in the liquid material, may enable a colored 3D object. The pigment may be specifically selected from C.I.pigment White 6, C.I.pigment Red3, C.I.pigment Red 5, C.I.pigment Red 7, C.I.pigment Red 9, C.I.pigment Red 12, C.I.pigment Red 13, C.I.pigment Red 21, C.I.pigment Red31, C.I.pigment Red49:1, C.I.pigment Red 58:1, C.I.pigment Red 175. C.i. pigment Yellow 63, c.i. pigment Yellow 3, c.i. pigment Yellow 12, c.i. pigment Yellow 16, c.i. pigment Yellow 83; one or more of C.I.pigment Blue 1, C.I.pigment Blue 10, C.I.pigment Blue B, phthalocyanine Blue BX, phthalocyanine Blue BS, C.I.pigment Blue61:1, and the like.

The dye is specifically selected from C.I. acid red 37, C.I. acid red 89 (weak acid red 3B, 2 BS), C.I. acid red 145 (weak acid scarlet GL), C.I. acid orange 67 (weak acid yellow RXL), C.I. acid orange 116 (acid orange AGT), C.I. acid orange 156 (weak acid orange 3G), C.I. acid yellow 42 (weak acid yellow Rs, acid yellow R), C.I. acid yellow 49 (acid yellow GR 200), C.I. acid blue 277, C.I. acid blue 344, C.I. acid blue 350, C.I. acid blue 9 (brilliant blue FCF), C.I. acid blue FCF c.i. green 17, c.i. acid green 28, c.i. acid green 41, c.i. acid green 81, c.i. acid violet 17 (acid violet 4 BNS), c.i. acid violet 54 (weak acid brilliant red 10B), c.i. acid violet 48, c.i. acid brown 75, c.i. acid brown 98, c.i. acid brown 165, c.i. acid brown 348, c.i. acid brown 349, c.i. acid black 26, c.i. acid black 63, c.i. acid black 172, c.i. acid black 194, c.i. acid black 210, c.i. acid black 234, c.i. acid black 235, c.i. acid black 242, and the like.

Fig. 2 is a schematic structural diagram of a three-dimensional object printing apparatus provided in a specific embodiment of the present application, and as shown in fig. 2, the embodiment of the present application further provides a three-dimensional object printing apparatus, configured to implement the three-dimensional object printing method, where the printing apparatus includes:

a powder supply part 2 for supplying a powder material to form a powder material layer;

a forming platform 1 for carrying the powder material layer;

a material dispenser 3 for applying a liquid material onto the powder material layer according to layer print data, forming a shaping layer comprising patterned areas and non-patterned areas, the patterned areas having a second height, wherein the second height is smaller than the first height and the second height is a preset layer thickness;

and a controller 4 for controlling the powder supplying part 2 and the material dispenser 3 to repeatedly perform the steps of forming the powder material layer to forming the molding layer, so that the obtained patterned areas of the plurality of molding layers are layered one by one to form a three-dimensional object.

In this embodiment, the powder supplying component 2 includes a powder storage cavity 23, a lifter 22 and a powder spreader 21, the powder storage cavity is used for storing the powder material 0, a movable supporting plate 231 is arranged in the powder storage cavity 23, the lifter 22 is connected with the supporting plate 231, and can drive the supporting plate 231 to ascend or descend in the Z direction; the powder spreader 21 is used to spread the powder material 0 in the powder storage chamber 23 onto the molding bed 1 to form a powder material layer L0, and a commonly used powder spreader 21 may be a powder spreading rod or a scraper.

A material dispenser 3, which can apply at least one liquid material to the layer of powder material according to the layer print data. In particular, the material dispenser 3 may be an inkjet printhead, which may be a single pass printhead or a multi-channel printhead, the number of printheads in this embodiment being dependent on the type of liquid material used and the amount of liquid material to be applied, e.g. when the liquid material comprises functional materials of different colours, the liquid materials of different colours are ejected through different printheads or different channels of the same printhead. For example, when the volume of a single ink droplet, which is larger than the amount of liquid material to be applied, is insufficient, a plurality of printheads or a plurality of channels may be simultaneously used to eject the same kind of material in order to improve printing efficiency.

During the shaping process, the liquid material infiltrates the layers of powder material such that each layer of powder material forms a shaped layer comprising patterned areas and non-patterned areas, and a three-dimensional object is formed by stacking the patterned areas of the shaped layers layer upon layer.

Further, the three-dimensional object printing apparatus may further include an energy supply device 5 for supplying energy to the powder material layer so that a patterned region of the powder material layer to which the liquid material is applied is formed, resulting in a formed layer of the three-dimensional object.

The energy provided by the energy supply means 5 may be radiant energy or thermal energy, and the energy supply means may be selected from at least one of an ultraviolet lamp, an infrared lamp, a microwave emitter, a heating wire, a heating sheet, a heating plate. The specific type of energy supply device and the type of liquid material to be selected are related to the type of powder material. When the active ingredient in the liquid material is subjected to photopolymerization, the energy supply device 5 supplies radiant energy such as ultraviolet radiation by which the active ingredient is induced to undergo photopolymerization; when the thermal polymerization reaction of the active ingredient in the liquid material occurs, the energy supply means supplies heat energy such as an infrared lamp, a microwave, a heating wire, a heating sheet, a heating plate, and the thermal polymerization reaction of the active ingredient is initiated by the heat energy. When the liquid material has an active component that reacts with the powder material, the initiator initiates polymerization of the liquid material with the powder material upon the application of energy, which is not limited herein.

Optionally, the three-dimensional object printing apparatus further includes a lifting mechanism 9, where the lifting mechanism 9 is connected to the forming platform 1, and drives the forming platform 1 to lift or descend in a vertical direction.

Optionally, the three-dimensional object printing apparatus further comprises a preheating part 6 and/or a heating part 7, wherein the preheating part 6 is used for preheating the powder material layer to promote the liquid material to dissolve or melt the powder material; a heating means 7 for heating the liquid material to promote dissolution or melting of the powder material; the preheating part 6 and the heating part 7 can be at least one selected from ultraviolet lamps, infrared lamps, microwave emitters, heating wires, heating plates and heating plates respectively.

In the present embodiment, the preheating part 6, the material dispenser 3, the heating part 7, and the power supply means 5 may be sequentially installed on the guide rail 8, and may be movable on the guide rail 8. In this embodiment, when the energy supply device 5 is a device for supplying heat energy, the heating member 7 may be omitted, and the powder material layer to which the liquid material is applied is heated by the energy supply device 5 and polymerization is initiated.

The three-dimensional object printing apparatus may further comprise a temperature monitor (not shown in the figures) for monitoring the temperature of the powder material layer.

Further, the controller 4 may control the operation of at least one of the powder feeding part 2, the material dispenser 3, the energy supply device 5, the preheating part 6, the heating part 7, and the temperature monitor. For example, the temperature monitor feeds back the monitored temperature to the controller 4, which controls the amount of energy provided by the preheating part 6 and/or the heating part 7 and the energy supply device 5 based on the information fed back by the temperature monitor. In particular, the controller 4 is connected to the various drive and dispensing assemblies of the three-dimensional object printing apparatus. The controller may comprise an ASIC or other type of suitable integrated circuit type controller. For example, the controller includes at least one processor and at least one storage medium. The storage medium includes a non-transitory computer readable memory for at least temporarily storing layer print data representing at least one three-dimensional object to be generated. The processor instructs the drive assembly and the dispensing assembly based on the layer print data and in accordance with other process-specific parameters stored on the storage medium.

Fig. 3 is a schematic flow chart of a three-dimensional object printing method according to another embodiment of the present application, and as shown in fig. 2 and fig. 3, the steps included in the three-dimensional object printing method according to the present application are described in detail:

step S01, a digital model of a three-dimensional object is obtained, the digital model of the three-dimensional object is sliced and layered to obtain a plurality of slice layers and layer image data, and layer printing data are generated according to the layer image data;

in a specific implementation manner, original data of a three-dimensional object can be obtained through a scanning mode and three-dimensional modeling is carried out to obtain a digital model of the three-dimensional object, or the three-dimensional object model is designed and built to obtain the digital model of the three-dimensional object, data format conversion is carried out on the digital model, for example, the digital model is converted into a format which can be identified by slicing software, such as an STL format, a PLY format, a WRL format and the like, then slicing and layering are carried out on the model through the slicing software to obtain slice layer image data, and layer image data are processed to obtain layer printing data representing the object. The layer print data includes information indicating the shape of the object, and/or information indicating the color of the object.

In step S10, a powder material is provided to form a layer of powder material having a first height H1.

In a specific embodiment, as shown in fig. 2, a powder material layer having a first height H1 may be formed by providing powder material onto the forming table 1 using a powder supply part 2.

Further, before applying the liquid material on the layer of powder material, the method further comprises: the powder material layer is preheated.

In a specific embodiment, as shown in fig. 2, after the powder material layer is formed, the preheating part 6 may preheat the powder material layer to raise the temperature of the powder material, which helps to raise the mixing uniformity of the liquid material and the powder material when the liquid material is applied on the powder material layer in step S12. The temperature of the preheating is related to the properties of the powder material used, alternatively the preheating temperature is lower than the melting point or melting temperature of the powder material. It will be appreciated that by controlling the preheating temperature to be below the melting point or melting temperature of the powder material in this embodiment, the powder material is prevented from sticking and penetration of the liquid material into the interstices between the particles of the powder material is facilitated.

And step S20, applying a liquid material onto the powder material layer according to layer printing data to form a molding layer, wherein the molding layer comprises a patterned area and a non-patterned area, and the patterned area has a second height, wherein the second height is smaller than the first height, and the second height is a preset layer thickness.

In a specific embodiment, the material dispenser 3 may apply liquid material on the powder material layer according to the layer print data to form patterned areas, the areas where no liquid material is applied being non-patterned areas; the liquid material permeates into the gaps of the powder material and covers the surface layer of the powder material, thereby wetting the surface of the powder material.

Further, after applying the liquid material on the powder material layer, the method further comprises:

the layer of powder material after application of the liquid material is energized to form a shaped layer.

In particular, the energy supply device 5 may be used to transform patterned areas formed in a layer of powder material to which a liquid material is applied into a shaping layer.

Illustratively, when the liquid material is a photocurable material, the liquid material contains a photocurable component, and the photocurable component is capable of dissolving the powder material, the photoinitiator initiates polymerization of the photocurable component upon the application of energy, such as radiant energy, by the energy supply device 5 to entangle and cure the dissolved powder molecules for molding.

Specifically, the formation of the molding layer may be achieved in various ways, either by solidifying the liquid material and integrally molding the powder material, or by melting and then cooling the powder material. In the case of a binder in the material, the binder may adhere the liquid material to the powder material and/or the molten powder material, and during curing the binder cures with the powder material and the liquid material. The energy supply means 5 may first apply energy (such as light or heat) to the powder material such that at least part of the powder material is heated to a molten state, thereby cooling and solidifying the powder material into one body. In yet another example, the energy supply device 5 may apply energy (such as light) after the powder material is melted, thereby promoting the powder material to integrate or solidify. Further, the energy provided by the energy supply means 5 may be applied to a mixture of powder material and liquid material, wherein the liquid material is capable of absorbing energy such that the powder material is solidified together with the liquid material.

Step S31, providing a powder material to form an n+1th powder material layer on the Nth molding layer, wherein the n+1th powder material layer has a first height, the first height is based on a patterned area of the Nth molding layer, and N is a natural number greater than or equal to 1.

And step S32, applying liquid material to the n+1th powder material layer according to the layer printing data to form an n+1th molding layer, wherein the patterning area of the n+1th molding layer has the second height.

As shown in fig. 4 and 5, the controller 4 is configured to control the powder supplying part 2 to supply the powder material to form the powder material layer 121 having the first height H1 on the nth molding layer based on the patterned region 112 of the nth molding layer; the control material dispenser 3 applies a liquid material on the powder material layer 121 according to the layer print data to form an n+1-th molding layer, the patterned region 122 of the n+1-th molding layer having a second height H2; the second height H2 is smaller than the first height H1, and the second height H2 is equal to the preset layer thickness.

It should be noted that the first height H1 of the first powder material layer 121 is based on the molding table 1, and the first height of the second powder material layer is based on the patterned region 112 of the first molding layer. That is, during the powder spreading process, the powder supply part 2 spreads the powder material on the upper surface of the patterned region 112 and the upper surface of the non-patterned region of the first molding layer. Since the non-patterned region can provide a portion of the powder material, the actual amount of powder spread of the powder material can be reduced, and the utilization rate of the powder material can be improved. Therefore, the part of the powder material layer 111 includes the powder material that is not formed in the previous forming layer and the newly added powder material, and the powder material that is not formed in the part of the N-th forming layer may be utilized in the forming process of the n+1-th forming layer, so that the powder material can be saved and the waste can be avoided.

Step S33, determining whether the n+1th molding layer is the last layer, if not, repeating the steps from forming the powder material layer to forming the molding layer, so that the obtained patterned areas of the molding layers are stacked one by one to form a three-dimensional object.

In the process of forming the three-dimensional object, after forming the forming layer of one three-dimensional object, the forming platform 1 is driven by the lifting mechanism 9 to descend by at least one distance of a preset layer thickness, and in this embodiment, the lifting mechanism 9 descends by at least one distance of a preset layer thickness with reference to the upper surface of the patterned area of the forming layer. The powder supply part 2 provides a new layer of powder material on top of the previously formed layer, the material dispenser 3 applying liquid material according to the layer print data forming patterned areas of the new formed layer on the powder material layer; this process is repeatedly performed to obtain patterned areas of the plurality of build-up layers stacked one upon the other to form a three-dimensional object.

In summary, the present application compensates for the problem of layer shrinkage caused by the reaction of the powder material and the liquid material in advance by providing an excessive amount of the powder material in each layer, so that the height of the formed molding layer is exactly equal to the preset layer thickness although being smaller than the height of the powder material layer, thereby improving the molding accuracy of the three-dimensional object.

The embodiment of the application further provides a non-transitory computer readable storage medium, as shown in fig. 6, where the storage medium 91 includes a stored program 911, and when the program runs, the device where the storage medium 91 is controlled to execute the three-dimensional object printing method described above.

The embodiment of the present application further provides a computer device, as shown in fig. 7, the computer device 100 of the embodiment includes: the processor 101, the memory 102, and the computer program 103 stored in the memory 102 and capable of running on the processor 101, when the processor 101 executes the computer program 103, the three-dimensional object printing method in the embodiment is implemented, and in order to avoid repetition, details are not described herein.

The computer device 100 may be a desktop computer, a notebook computer, a palm computer, a cloud server, or the like. Computer devices may include, but are not limited to, processor 101, memory 102. It will be appreciated by those skilled in the art that fig. 7 is merely an example of computer device 100 and is not limiting of computer device 100, and may include more or fewer components than shown, or may combine certain components, or different components, e.g., a computer device may also include an input-output device, a network access device, a bus, etc.

The processor 101 may be a central processing unit (Central Processing Unit, CPU), but may also be other general purpose processors, digital signal processors (Digital Signal Processor, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), field programmable gate arrays (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 102 may be an internal storage unit of the computer device 100, such as a hard disk or a memory of the computer device 100. The memory 102 may also be an external storage device of the computer device 100, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash Card (Flash Card) or the like, which are provided on the computer device 100. Further, the memory 102 may also include both internal storage units and external storage devices of the computer device 100. The memory 102 is used to store computer programs and other programs and data required by the computer device. The memory 102 may also be used to temporarily store data that has been output or is to be output.

The foregoing description of the preferred embodiment of the present invention is not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

Claims

1. A method of printing a three-dimensional object, the method comprising:

providing a powder material to form an n+1th powder material layer on an N-th molding layer, wherein the n+1th powder material layer has the first height, the first height is based on a patterned region of the N-th molding layer, the first height is obtained according to the second height and the shrinkage rate of the powder material layer, and N is a natural number greater than or equal to 1;

2. The method according to claim 1, characterized in that the shrinkage rate r= (R _{Front part} -R _{Rear part (S)} )/R _{Front part} *100, wherein R is _{Front part} Refers to the thickness of the powder material layer before shrinkage, R _{Rear part (S)} Refers to the thickness of the powder material layer after shrinkage.

3. The method of claim 1, wherein the powder material is selected from at least one of polystyrene, polyvinyl chloride, polyacrylonitrile, acrylonitrile-styrene-acrylate copolymer, polyamide, polyester, polyurethane, polylactic acid, poly (meth) acrylate, poly (meth) methyl acrylate, polyvinyl fluoride, chlorinated polyolefin, hydroxyl-containing polyvinyl alcohol, cellulose, modified cellulose.

4. The method of claim 1, wherein the predetermined layer thickness is a constant value.

5. The method according to claim 1, wherein the method satisfies at least one of the following characteristics:

a. The liquid material dissolves at least a portion of the powder material;

d. the liquid material melts at least a portion of the powder material.

6. The method of claim 1, wherein prior to the applying liquid material on the layer of powder material according to layer print data, the method further comprises:

preheating the layer of powder material.

7. The method of claim 1, wherein after the applying liquid material to the layer of powder material according to layer print data, the method further comprises:

8. The method of claim 7, wherein the energy comprises at least one of radiant energy and thermal energy.

9. A three-dimensional object printing apparatus for carrying out the three-dimensional object printing method according to any one of the preceding claims 1 to 8, characterized in that the printing apparatus comprises:

a powder supply part for supplying a powder material to form a powder material layer having a first height;

A forming platform for carrying the powder material layer;

a material dispenser for applying a liquid material to the powder material layer according to layer print data to form a shaping layer, the shaping layer comprising patterned and non-patterned regions, the patterned regions having a second height, wherein the second height is less than the first height and the second height is a preset layer thickness; the first height is obtained according to the second height and the shrinkage rate of the powder material layer;

and a controller for controlling the powder supply part and the material dispenser to repeatedly perform the steps of forming the powder material layer to forming the molding layers, so that the obtained patterning areas of the plurality of molding layers are stacked one by one to form a three-dimensional object, wherein the (n+1) th powder material layer has the first height, the first height is based on the patterning area of the (N) th molding layer, and N is a natural number greater than or equal to 1.

10. The three-dimensional object printing apparatus according to claim 9, wherein the printing apparatus further comprises:

11. The three-dimensional object printing apparatus according to claim 10, further comprising a lifting mechanism connected to the modeling platform to drive the modeling platform to rise or fall in a vertical direction.

12. The three-dimensional object printing apparatus according to claim 10, further comprising a preheating component for preheating the powder material layer and/or a heating component; the heating member is for heating the liquid material.

13. The apparatus according to claim 12, wherein the energy supply device, the preheating part and the heating part are each at least one selected from the group consisting of an ultraviolet lamp, an infrared lamp, a microwave emitter, a heating wire, a heating sheet, and a heating plate.

14. The three-dimensional object printing apparatus of claim 9, further comprising a temperature monitor for monitoring the temperature of the layer of powder material.

15. A non-transitory computer-readable storage medium, characterized in that the storage medium includes a stored program that, when executed, controls a device in which the storage medium is located to perform the three-dimensional object printing method according to any one of claims 1 to 8.

16. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, characterized in that the processor implements the three-dimensional object printing method according to any one of claims 1-8 when executing the computer program.