Three-dimensional object printing method and device, three-dimensional printing material

Abstract

The present application provides a printing method and apparatus for a three-dimensional object, and a three-dimensional printing material, the printing method includes the steps of: forming a powder material layer including a molded region and a non-molded region using a powder material; injecting a first liquid material and a second liquid material in the molded region of the powder material layer at a first ratio according to layer printing data, which promotes a polymerization reaction of the first liquid material to form a layer solid portion of the three-dimensional object; and injecting the first liquid material and the second liquid material in the non-molded region of the powder material layer at a second ratio according to the layer printing data to form a layer protection portion of the three-dimensional object, the first ratio being greater than the second ratio. The printing method and apparatus for a three-dimensional object, and the three-dimensional printing material provided by the embodiments of the present application can enhance the storage stability of the liquid material, improve the surface accuracy of the three-dimensional object, and reduce the difficulty of post-processing.

Description

[Technical field]

[0001] The present application relates to the field of three-dimensional printing technology, and in particular to a method and apparatus for printing three-dimensional objects, and three-dimensional printing materials. [Background technology]

[0002] The main process of three-dimensional object additive manufacturing technology is to obtain a digital model of a three-dimensional object, slice the digital model into layers, and perform data processing and conversion for each sliced ​​layer to obtain printing data for each sliced ​​layer. A printing device prints and stacks layers according to the sliced ​​layer printing data to manufacture a three-dimensional object.

[0003] In the conventional three-dimensional object additive manufacturing technology, the technology of combining powder and inkjet printing, for example, in the powder material layer, the print head injects the liquid material into the molding area according to the layer printing data of the three-dimensional object, and then supplies radiation to polymerize the liquid material to encapsulate the powder particles in contact with the liquid material to form a layer of the three-dimensional object, or the liquid material contains a radiation absorber, which absorbs radiation and converts it into thermal energy to melt the powder particles in contact with the liquid material to form a layer of the three-dimensional object. However, this type of three-dimensional object additive manufacturing technology has the problem that the injected liquid material penetrates into the non-molding area, and the powder particles in the non-molding area adhere to and encapsulate the surface of the adjacent three-dimensional object, or the powder particles in the non-molding area melt and stick to the surface of the three-dimensional object, which ultimately increases the surface roughness of the three-dimensional object and makes post-processing difficult.

[0004] Therefore, in additive manufacturing technology that combines powder and inkjet printing, how to improve the surface accuracy of three-dimensional objects and reduce the difficulty of post-processing of the three-dimensional objects has become a technical problem that must be solved by those skilled in the art. Summary of the Invention [Problem to be solved by the invention]

[0005] The embodiments of the present application provide a three-dimensional object printing method and apparatus, and a three-dimensional printing material, which can increase the storage stability of liquid materials, improve the surface precision of three-dimensional objects, and reduce the difficulty of post-processing. [Means for solving the problem]

[0006] In a first aspect, the present application provides a method of printing a three-dimensional object, the method comprising the steps of: forming a powder material layer using the powder material, the powder material layer including formed and non-formed regions; adding, in a first ratio according to layer print data, within a molding area of ​​the powder material layer, a first liquid material and a second liquid material that promotes a polymerization reaction of the first liquid material to form a layer substantial portion of a three-dimensional object; and adding a first liquid material and a second liquid material in a second ratio in a non-molded area of ​​the powder material layer according to layer printing data to form a layer protection portion of the three-dimensional object, wherein the first ratio is greater than the second ratio, such that the amount of the second liquid material in a unit volume of the molding area is less than the amount of the second liquid material in a unit volume of at least partial non-molded area, and the amount of the first liquid material in a unit volume of the molding area is greater than the amount of the first liquid material in a unit volume of at least partial non-molded area.

[0007] With reference to the first aspect, in one possible embodiment, the first ratio is a volume ratio of the first liquid material to the second liquid material, the first ratio being (1 to 10):1, and / or the second ratio is a volume ratio of the first liquid material to the second liquid material, the second ratio being (0 to 0.95):1.

[0008] Referring to the first aspect, in one possible embodiment, the layer substance portion and the layer protection portion are located on the same horizontal plane, and the layer substance portion and the layer protection portion are arranged adjacent to each other.

[0009] With reference to the first aspect, in one possible embodiment, the amount of second liquid material per unit volume of the non-molding region gradually decreases along a direction away from the molding region.

[0010] Referring to the first aspect, in one possible embodiment, the width of the layer protection portion is greater than or equal to the smallest diameter of droplets of the applied first and second liquid materials.

[0011] With reference to the first aspect, in one possible embodiment, before the step of adding a first liquid material and a second liquid material in a shaped area of ​​the powder material layer in a first ratio according to layer printing data, and ejecting the first liquid material and the second liquid material in a second ratio in a non-shaped area of ​​the powder material layer in accordance with layer printing data, the method for printing a three-dimensional object includes: The method further includes pre-heating the powder material layer.

[0012] Referring to the first aspect, in one possible embodiment, the preheating temperature is 5° C. to 100° C. lower than the melting point or melting temperature of the powder material.

[0013] With reference to the first aspect, in one possible embodiment, after the step of adding a first liquid material and a second liquid material in a second ratio in the non-shaped areas of the powder material layer according to layer printing data, the method for printing the three-dimensional object comprises: The method further includes the step of heating the powder material bed to which the second liquid material has been added.

[0014] Referring to the first aspect, in one possible embodiment, the heating temperature is higher than 70°C and at least 5°C lower than the melting point or melting temperature of the powder material in order to promote evaporation of water in the second liquid material and / or promote dissolution of the powder material by the first liquid material and promote the polymerization reaction of the first liquid material.

[0015] Referring to the first aspect, in one possible embodiment, the pre-heating and heating energy includes at least one of radiant energy and thermal energy.

[0016] Referring to the first aspect, in one possible embodiment, the first liquid material includes a first active ingredient that at least partially dissolves the powder material, and the second liquid material includes a second auxiliary agent for promoting a polymerization reaction of the first liquid material, a powder release agent, a stripping agent, a hydrocarbon chain surfactant, and water.

[0017] With reference to the first aspect, in one possible embodiment, when the total weight of the second liquid material is taken as 100%, the second liquid material includes, by weight, 0.1% to 40% of a second auxiliary, 30% to 90% of water, 0.01% to 10% of a powder release agent, 1% to 30% of a stripping agent, and 0.1% to 10% of a hydrocarbon chain surfactant.

[0018] Referring to the first aspect, in one possible embodiment, (1) The second assistant is at least one selected from an initiator, an initiation promoter, and a catalyst; (2) The powder release agent is at least one selected from the group consisting of a silicon-containing water-soluble release agent, a silicon-containing water-dispersible release agent, a fluorine-containing water-soluble release agent, and a fluorine-containing water-dispersible release agent. (3) The powder release agent is at least one selected from the group consisting of a silicone oil emulsion, a fluorine-containing nonionic surfactant, and a fluorine-containing anionic surfactant; (4) The release agent is selected from at least one of a water-soluble polymer and a water-dispersible polymer having a glass transition temperature of less than 40° C.; (5) The release agent satisfies at least one of the following characteristics: the release agent is at least one selected from the group consisting of polyether resins, polyester resins, poly(methyl)acrylate resins, and polyurethane resins, each having a glass transition temperature lower than 40°C.

[0019] Referring to the first aspect, in one possible embodiment, the second liquid material contains, by weight, 0.05% to 30% of a co-solvent.

[0020] Referring to the first aspect, in one possible embodiment, the co-solvent is at least one selected from an alcohol, an alcohol ether, an amide, a pyrrolidone, an organic acid, and an organic salt.

[0021] Referring to the first aspect, in one possible embodiment, after the step of forming a layer substantial portion and a layer protection portion of the three-dimensional object, the printing method of the three-dimensional object includes: The method further includes a step of repeatedly forming a powder material layer and adding a first liquid material and a second liquid material to stack the obtained sliced ​​layers, each of which includes a layer substance portion and a layer protection portion, layer by layer to form a three-dimensional object.

[0022] In a second aspect, an embodiment of the present application provides a non-transitory computer-readable storage medium, the storage medium including a program stored therein, the program, when executed, controlling an apparatus equipped with the storage medium to perform the above-mentioned method of printing a three-dimensional object.

[0023] In a third aspect, an embodiment of the present application provides a computing device including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the above-mentioned method for printing a three-dimensional object is implemented when the processor executes the computer program.

[0024] In a fourth aspect, an embodiment of the present application provides a three-dimensional object obtained by printing according to the method for printing a three-dimensional object described above.

[0025] In a fifth aspect, embodiments of the present application provide a three dimensional printing material for use with a powder material for three dimensional printing, the three dimensional printing material comprising a first liquid material and a second liquid material; the first liquid material comprises a first active ingredient capable of at least partially dissolving the powder material; When the total weight of the second liquid material is 100%, the second liquid material contains, by weight, 0.1% to 40% of a second auxiliary for promoting the polymerization reaction of the first liquid material, 30% to 90% water, 0.01% to 10% powder release agent, 1% to 30% stripping agent, and 0.1% to 10% hydrocarbon chain surfactant.

[0026] In a sixth aspect, embodiments of the present application provide a three dimensional printing material, the three dimensional printing material comprising a powder material, a first liquid material, and a second liquid material; the powder material is used to form a powder material layer, the first liquid material includes a first active ingredient that at least partially dissolves the powder material; When the total weight of the second liquid material is 100%, the second liquid material contains, by weight, 0.1% to 40% of a second auxiliary for promoting the polymerization reaction of the first liquid material, 30% to 90% water, 0.01% to 10% powder release agent, 1% to 30% stripping agent, and 0.1% to 10% hydrocarbon chain surfactant.

[0027] Referring to the sixth aspect, in one possible embodiment, the powder material layer includes a shaping region in which the first liquid material and the second liquid material are added in a first ratio, and a non-shaping region in which the first liquid material and the second liquid material are added in a second ratio, the first ratio being greater than the second ratio.

[0028] With reference to the sixth aspect, in one possible embodiment, the first ratio is a volume ratio of the first liquid material to the second liquid material, the first ratio being (1 to 10):1, and / or the second ratio is a volume ratio of the first liquid material to the second liquid material, the second ratio being (0 to 0.95):1.

[0029] With reference to the sixth aspect, in one possible embodiment, the amount of the second liquid material in a unit volume of the molding region is less than the amount of the second liquid material in a unit volume of at least a portion of the non-molding region, and the amount of the first liquid material in a unit volume of the molding region is greater than the amount of the first liquid material in a unit volume of at least a portion of the non-molding region.

[0030] Referring to the sixth aspect, in one possible embodiment, the powder material comprises at least one of polystyrene, polyvinyl chloride, polyacrylonitrile, acrylonitrile-styrene-acrylate copolymers, polyamides, polyesters, polyurethanes, poly(methyl)acrylates, polyvinyl fluorides, chlorinated polyolefins, block and / or graft copolymers soluble in the first active ingredient, hydroxyl-containing polyvinyl alcohol, cellulose, modified cellulose.

[0031] With reference to the fifth or sixth aspect, in one possible embodiment, the first active component has an active group capable of participating in a polymerization reaction, the active group comprising at least one of a carbon-carbon double bond, a hydroxyl, a carboxyl, a heterocyclic propane group, a carbonate-based group, an epoxy group, a liquid cyclic lactone structure, and a cyclic acetal structure.

[0032] Referring to the fifth or sixth aspect, in one possible embodiment, the first liquid material comprises a second active ingredient having an active group capable of participating in a polymerization reaction and not dissolving the powder material, The second active ingredient includes at least one of isobornyl acrylate, isobornyl methacrylate, dodecyl acrylate, dodecyl methacrylate, cyclic trimethylolpropane formal acrylate, a carbon-carbon double bond-containing prepolymer, an epoxy group-containing prepolymer, a monomer that promotes ring-opening polymerization of an epoxy group, a prepolymer that promotes ring-opening polymerization of an epoxy group, a solid cyclic lactone, and a cyclic amide-based compound.

[0033] With reference to the fifth or sixth aspect, in one possible embodiment, when the total weight of the first liquid material is 100%, the weight percentage of the first active ingredient in the first liquid material is 10% to 95%.

[0034] With reference to the fifth or sixth aspect, in one possible embodiment, when the total weight of the first liquid material is 100%, the weight percentage of the second active ingredient in the first liquid material is 5% to 90%.

[0035] With reference to the fifth or sixth aspect, in one possible embodiment, when the total weight of the first liquid material is 100%, the first liquid material further contains, by weight, 0.01% to 30% of a first auxiliary agent.

[0036] The first auxiliary agent includes at least one of a high temperature initiator, a leveling agent, an antifoaming agent, a polymerization inhibitor, an antioxidant, a plasticizer, a dispersant, a pigment, and a dye.

[0037] With reference to the fifth or sixth aspect, in one possible embodiment, (1) The second assistant is at least one selected from an initiator, an initiation promoter, and a catalyst; (2) The powder release agent is at least one selected from the group consisting of a silicon-containing water-soluble release agent, a silicon-containing water-dispersible release agent, a fluorine-containing water-soluble release agent, and a fluorine-containing water-dispersible release agent. (3) The powder release agent is at least one selected from the group consisting of a silicone oil emulsion, a fluorine-containing nonionic surfactant, and a fluorine-containing anionic surfactant; (4) The release agent is selected from water-soluble polymers and / or water-dispersible polymers having a glass transition temperature of less than 40° C.; (5) The release agent satisfies at least one of the following characteristics: the release agent is at least one selected from the group consisting of polyether resins, polyester resins, poly(methyl)acrylate resins, and polyurethane resins, each having a glass transition temperature lower than 40°C.

[0038] With reference to the fifth or sixth aspect, in one possible embodiment, when the total weight of the second liquid material is 100%, the second liquid material further contains, by weight, 0.05% to 30% of a co-solvent.

[0039] Referring to the fifth or sixth aspect, in one possible embodiment, the co-solvent is at least one selected from an alcohol, an alcohol ether, an amide, a pyrrolidone, an organic acid, and an organic salt.

[0040] With reference to the fifth or sixth aspect, in one possible embodiment, the hydrocarbon chain surfactant is one or more selected from fatty alcohol polyoxyethylene ethers, sodium alkyl sulfonates, sodium alkyl benzene sulfonates, sodium alkyl sulfates, sodium alkyl succinic acid sulfonates, sodium sulfamate, polyethers, polyoxyethylene polyoxypropylene ether block copolymers.

[0041] In a seventh aspect, embodiments of the present application provide an apparatus for printing a three-dimensional object, the apparatus comprising a powder supply member, a building platform, a print head, and a controller; The powder supplying member supplies a powder material to form a powder material layer including a molded region and a non-molded region, the building platform supports the formed layer of powder material; the controller controls the print head to dispense, in a first ratio, a first liquid material and a second liquid material, which promotes a polymerization reaction of the first liquid material to form a layer substantial portion of the three-dimensional object, within a molding area of ​​the powder material layer according to layer printing data; The controller controls the print head to add a first liquid material and a second liquid material in a second ratio in a non-molded area of ​​the powder material layer according to layer printing data to form a layer protection portion of the three-dimensional object, the first ratio being greater than the second ratio, such that the amount of the second liquid material in a unit volume of the molding area is less than the amount of the second liquid material in a unit volume of at least partial non-molded area, and the amount of the first liquid material in a unit volume of the molding area is greater than the amount of the first liquid material in a unit volume of at least partial non-molded area.

[0042] With reference to the seventh aspect, in one possible embodiment, the print head includes a first orifice array for ejecting a first liquid material and a second liquid material in a first ratio, and a second orifice array for ejecting the first liquid material and the second liquid material in a second ratio.

[0043] With reference to the seventh aspect, in one possible embodiment, the print head includes a first orifice array and a second orifice array used for ejecting a first liquid material and a second liquid material, respectively, in a first ratio in the molding area, and for ejecting the first liquid material and the second liquid material, respectively, in a second ratio in the non-molding area.

[0044] With reference to the seventh aspect, in one possible embodiment, the printing apparatus for the three-dimensional object further includes a lifting mechanism, and each time one three-dimensional object slice layer including a layer solid portion and a layer protection portion is formed, the lifting mechanism drives the molding platform to move downward a distance equivalent to the thickness of one powder layer.

[0045] With reference to the seventh aspect, in one possible embodiment, the three dimensional printing apparatus further includes a pre-heating member, the pre-heating member being disposed above the molding platform and pre-heating the powder material layer.

[0046] With reference to the seventh aspect, in one possible embodiment, the three dimensional printing apparatus further includes a heating member, the heating member being positioned above the molding platform and configured to heat the powder material layer onto which the second liquid material is jetted. Effect of the Invention

[0047] The technical solution of the present application has at least the following beneficial effects:

[0048] The three-dimensional object printing method provided by the present application not only helps to increase the storage stability of the liquid material and improve the fluency of inkjet printing of the liquid material by storing the first liquid material and the second liquid material separately and adding them in different composition ratios to the molded and non-molded areas of the powder material layer, but also helps to reduce the temperature of the non-molded areas and reduce the effect of the first liquid material on the powder material in the non-molded areas, thereby reducing the difficulty of post-processing of the printed three-dimensional object, especially the difficulty of post-processing of the surface of the three-dimensional object, and as a result, improving the surface accuracy of the printed product.

[0049] For the three-dimensional printing material provided by the present application, the first liquid material and the second liquid material are different types of liquid materials, and the second liquid material contains a component for promoting the polymerization reaction of the first liquid material. By storing the first liquid material and the second liquid material separately, the storage stability of the liquid materials is enhanced, which helps to improve the fluency of inkjet printing of the liquid materials.

[0050] The second liquid material contains water, which evaporates when energy is supplied to the powder material layer to which the second liquid material has been added, increasing the concentration of the second auxiliary agent, thereby accelerating the polymerization reaction rate of the first active component, and when a sufficient amount of water evaporates, it can take the temperature of the powder material in the non-molding region, thereby preventing the powder material in the non-molding region from melting and / or sticking, and the use of water is less costly and more environmentally friendly than the use of other volatile solvents. The second liquid material contains a powder release agent, which helps to improve the surface accuracy of the edge of the molding region when the content of the second liquid material per unit volume sprayed into the molding region of the powder material layer is smaller than the content of the second liquid material per unit volume of the non-molding region. The second liquid material contains a release agent, which, when sprayed into the non-molding region of the powder material, causes the powder in the non-molding region at the edge of the molding region to stick, facilitating the release of the powder in the non-molding region and facilitating separation from the powder in other non-molding regions during powder recovery. The mixing ratio of the second liquid material contributes to reducing the difficulty of post-processing of the printed three-dimensional object, thereby improving the surface accuracy of the printed product and also contributing to the recovery of powder in non-molded areas. [Brief description of the drawings]

[0051] In order to more clearly describe the technical solutions of the embodiments of the present application, the following briefly describes the drawings that need to be used in the description of the embodiments. Of course, the drawings described below are some embodiments of the present application, and those skilled in the art can think of other drawings based on these drawings without creative efforts. [Figure 1] 1 is a flowchart of a method for printing a three-dimensional object provided by an embodiment of the present application. [Diagram 2] 1 is a flowchart of a method for printing a three-dimensional object provided by another embodiment of the present application. [Figure 3a] FIG. 2 is a schematic diagram of a structure of a three-dimensional object to be printed according to an embodiment of the present application. [Figure 3b]FIG. 2 is a structural schematic diagram of a powder material layer provided according to an embodiment of the present application. [Figure 4a] FIG. 2 is a structural schematic diagram of the falling point of an ink droplet when a first liquid material and a second liquid material provided by an embodiment of the present application are ejected in a predetermined ratio. [Figure 4b] FIG. 2 is a structural schematic diagram of the falling point of an ink droplet when a first liquid material and a second liquid material provided by an embodiment of the present application are ejected in a predetermined ratio. [Figure 4c] FIG. 2 is a structural schematic diagram of the falling point of an ink droplet when a first liquid material and a second liquid material provided by an embodiment of the present application are ejected in a predetermined ratio. [Figure 4d] FIG. 2 is a structural schematic diagram of the falling point of an ink droplet when a first liquid material and a second liquid material provided by an embodiment of the present application are ejected in a predetermined ratio. [Figure 4e] FIG. 2 is a structural schematic diagram of the falling point of an ink droplet when a first liquid material and a second liquid material provided by an embodiment of the present application are ejected in a predetermined ratio. [Diagram 5] 1 is a flowchart of a method for printing a three-dimensional object provided by another embodiment of the present application. [Figure 6] FIG. 1 is a structural schematic diagram of a three-dimensional object printing apparatus provided by an embodiment of the present application. [Figure 7a] FIG. 2 is a schematic diagram of a local structure of a liquid supply device in a printing apparatus for a three-dimensional object provided by an embodiment of the present application. [Figure 7b] FIG. 2 is a schematic diagram of a local structure of a liquid supply device in a printing apparatus for a three-dimensional object provided by an embodiment of the present application. [Figure 7c] FIG. 2 is a schematic diagram of a local structure of a liquid supply device in a printing apparatus for a three-dimensional object provided by an embodiment of the present application. [Figure 8a] FIG. 2 is a schematic diagram of the surface structure of a print head nozzle in a three-dimensional object printing device provided by an embodiment of the present application. [Figure 8b] FIG. 2 is a schematic diagram of the surface structure of a print head nozzle in a three-dimensional object printing device provided by an embodiment of the present application. [Figure 8c]FIG. 2 is a schematic diagram of the surface structure of a print head nozzle in a three-dimensional object printing device provided by an embodiment of the present application. [Figure 9] 1 is a schematic diagram of a non-transitory computer-readable storage medium provided by an embodiment of the present application. [Figure 10] FIG. 2 is a structural schematic diagram of a computer device provided by an embodiment of the present application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0052] In order to better understand the technical solutions of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0053] It should be clear that the described embodiments are only some of the embodiments of the present application, but not all of the embodiments. Based on the embodiments of the present application, all other embodiments obtained by a person skilled in the art without creative labor shall fall within the scope of protection of the present application.

[0054] The terms used in the examples of this application are used only for the purpose of describing specific examples, and are not intended to limit the present application. The singular forms "a," "the," and "the" used in the examples of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0055] It should be understood that the term "and / or" used herein is only used to describe the relational relationship of related objects and indicates that three relations may exist, for example, A and / or B may indicate three cases: A exists alone, A and B exist simultaneously, and B exists alone. Also, the character " / " in this specification generally indicates that the related objects before and after it are in an "or" relationship. In this specification, "eject" and "add" have the same meaning and refer to ejecting liquid material in a material storage container through a print head orifice.

[0056] The present application describes an additive manufacturing technology that combines powder materials and inkjet printing, and relates to a method for printing a three-dimensional object, materials required for printing a three-dimensional object, the printed three-dimensional object, a computer-readable storage medium having program instructions stored thereon, a computer device, and an apparatus for printing a three-dimensional object using the method for printing a three-dimensional object of the present application, which can improve the surface accuracy of the target three-dimensional object and reduce the difficulty of post-processing.

[0057] In one aspect, embodiments of the present application provide a three dimensional printing material, the material comprising a powder material, a first liquid material, and a second liquid material; The powder material is used to form a powder material layer, the first liquid material includes a first active ingredient that at least partially dissolves the powdered material; When the total weight of the second liquid material is 100%, the second liquid material contains, by weight, 0.1% to 40% of a second auxiliary for promoting the polymerization reaction of the first liquid material, 30% to 90% water, 0.01% to 10% powder release agent, 1% to 30% stripping agent, and 0.1% to 10% hydrocarbon chain surfactant.

[0058] In the three-dimensional printing material provided by the present application, the powder material layer formed by the powder material includes a molded region and a non-molded region, the first liquid material and the second liquid material are different types of liquid materials, and the second liquid material includes a second auxiliary agent for promoting the polymerization reaction of the first liquid material, specifically, the second auxiliary agent promotes the polymerization reaction of the first active component of the first liquid material to form a substantial part of the three-dimensional object. The first liquid material and the second liquid material are stored separately, which helps to increase the storage stability of the liquid materials and improve the fluency of the inkjet printing of the liquid materials.

[0059] The second liquid material contains water, which evaporates when energy is supplied to the powder material layer to which the second liquid material is added, and can increase the concentration of the second auxiliary in the second liquid material, whereby the high concentration of the second auxiliary in the powder material layer can increase the rate of the polymerization reaction of the first active component, and when a sufficient amount of water evaporates, it can take away the temperature of the powder material in the non-molding region of the powder material layer, thereby preventing the powder material in the non-molding region from melting and / or sticking. In addition, the use of water is less costly and more environmentally friendly than the use of other volatile solvents. The second liquid material further contains a powder release agent that helps to improve the surface accuracy of the edge of the molding region, and the second liquid material further contains a release agent, which helps to release the powder material in the non-molding region from the solid part formed in the molding region, and contributes to separating the recovered powder material from the powder in other non-molding regions. The mixing ratio of the second liquid material contributes to reducing the difficulty of post-processing of the printed three-dimensional object, thereby improving the surface accuracy of the printed product and also contributing to the recovery of powder in non-molded areas.

[0060] In some embodiments, the liquid material may be configured as a three-dimensional printing material and may be combined with an appropriate powder material for printing. In other embodiments, the liquid material may be combined with a powder material for use as a three-dimensional printing material, allowing consumers to use it directly to print three-dimensional objects.

[0061] In some examples, the powder material is in the form of powdered material particles and may be a metallic powder material or a non-metallic powder material.

[0062] The non-metallic powder material is selected from organic polymer powder materials that do not undergo a polymerization reaction with either the first liquid material or the second liquid material, and when the second liquid material comes into contact with the first liquid material at a specific ratio and under appropriate temperature conditions, the second liquid material promotes the polymerization reaction of the first liquid material, and the strength of the polymer formed by the polymerization reaction differs depending on the difference in the ratio between the first liquid material and the second liquid material, so that the strength of the solid part (corresponding to the molded area) and the protective part (corresponding to the non-molded area) of the three-dimensional object formed by printing is different.

[0063] In some embodiments, the organic polymer powder material may be selected from polypropylene, which in practical application cannot be dissolved by the first liquid material.

[0064] In some embodiments, the organic polymer powder material may be at least one selected from polystyrene (PS), polyvinyl chloride (PVC), polyacrylonitrile (PAN), acrylonitrile-styrene-acrylate copolymer (ASA), polyamide (PA), polyester, polyurethane (PU), poly(methyl)acrylate, polyvinyl fluoride, chlorinated polyolefin, block and / or graft copolymers soluble in the first active ingredient, hydroxyl-containing polyvinyl alcohol (PVA), cellulose, modified cellulose, etc. In practical application, the above organic polymer powder materials can be dissolved by the first liquid material.

[0065] In some embodiments, the powder material may further include additives including at least one of flow aids and fillers. The flow aids are for improving the flowability of the powder material, and the flow aids may be, for example, silicon dioxide, talc, etc., and the fillers are for improving the mechanical strength of the three-dimensional object, and the fillers may be, for example, graphene, carbon nanotubes, carbon fibers, glass bubbles, glass fibers, kaolin, etc., but are not limited in this embodiment.

[0066] In each embodiment of the present application, the melting point or melting temperature of the organic polymer powder material may be 60°C to 300°C, specifically, 60°C, 70°C, 80°C, 100°C, 120°C, 150°C, 180°C, 200°C, 240°C, 280°C, or 300°C, etc., and of course, may be other values ​​within the above range and are not limited herein.

[0067] In each embodiment of the present application, the particle shape and particle size of the powder material are not particularly limited. Optionally, the powder material may be at least one of the following shapes: spherical, branched, sliced, disk-shaped, needle-shaped, and rod-shaped. The average particle size of the powder material is 1 μm to 400 μm, such as 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, or other values ​​within the above ranges, and is not limited herein. The average particle size of the powder material is preferably 30 μm to 200 μm. The particle gap of the powder material is approximately 5 nm to 100 μm, for example, 5 nm, 10 nm, 100 nm, 250 nm, 500 nm, 1 μm, 5 μm, 10 μm, 25 μm, 50 μm, 75 μm, or 100 μm, or other values ​​within the above range, and is not limited herein. By making the particle gap of the powder material in each embodiment of the present application within the range of 5 nm to 100 μm, the liquid material can quickly penetrate into the powder material layer through the gap and retain a part of it on the surface layer, and further wet the surface of the powder material in the selected area, contributing to at least partially dissolving the powder material. Note that dissolution in each embodiment of the present application refers to all possible cases except when it is not completely dissolved.

[0068] In each embodiment of the present application, the first active ingredient may include only one substance capable of dissolving the powdered material, or may be a mixture including multiple substances capable of dissolving the powdered material, and the multiple substances may have different or the same solubilities in the powdered material.

[0069] In this embodiment, dissolution refers to all possible cases except when not completely dissolved. For example, when 1 g of powder material is put into 100 g of active ingredient, at most 1% of the powder material dissolves. Preferably, the first active ingredient completely dissolves the powder material. Dissolution is not limited to room temperature, and dissolution of the powder material into the active ingredient may be achieved by heating and / or stirring, and dissolution is not limited to one dissolution, and dissolution may be performed stepwise in several steps, for example, when the active ingredient dissolves slowly when it comes into contact with the powder material, the powder material can be heated to increase the dissolution rate. Preferably, the first active ingredient completely dissolves the powder material in contact with the first active ingredient.

[0070] In this particular embodiment, the weight ratio of the first active ingredient in the first liquid material is 10% to 95% when the total weight of the liquid material is 100%. For example, it may be 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 95%, and of course, the weight ratio can be proportional to the actual usage situation, and is not limited in this specification. Preferably, the weight ratio of the first active ingredient in the liquid material is 30% to 95%. In this embodiment, the weight ratio of the first active ingredient in the first liquid material is 30% or more, and by increasing the ratio of the first active ingredient in the first liquid material, the dissolution speed and dissolution degree of the first active ingredient in the powder material can be improved, thereby improving the mechanical strength of the printed matter.

[0071] Specifically, the first active component has an active group capable of participating in a polymerization reaction, and the active group includes at least one of a carbon-carbon double bond, a hydroxyl, a carboxyl, an ethylene sulfide group, a carbonate ester group, an epoxy group, a liquid cyclic lactone structure, and a cyclic acetal structure. Note that the first active component does not undergo a polymerization reaction with the powder material.

[0072] The first active ingredient may be at least one selected from a carbon-carbon double bond-containing monomer, a composition of a substance containing an epoxy group and a substance that promotes ring-opening polymerization of the epoxy group, a cyclic lactone, a thioheterocyclic compound, a carbonate compound, and a cyclic amide compound.

[0073] Specifically, the carbon-carbon double bond-containing monomer may be a (methyl)acrylate type, a vinyl ether type, an allyl ether type, styrene, acryloylmorpholine, N-vinylpyrrolidone, or the like.

[0074] The composition of the material containing epoxy groups and the material promoting ring-opening polymerization of the epoxy groups may be an epoxy diluent-containing and / or hydroxyl-containing small molecule or prepolymer, an epoxy diluent and / or a carboxyl-containing small molecule or prepolymer. The cyclic lactone may be γ-butyrolactone, δ-pentanolactone, ε-caprolactone, and the like.

[0075] Examples of the thioheterocyclic compounds include ethylene sulfide and thietane.

[0076] The carbonate ester compound may be dimethyl carbonate, diethyl carbonate, or the like.

[0077] The cyclic amide compound may be caprolactam or the like.

[0078] Illustratively, the first active ingredient may be styrene or gamma-butyrolactone, and the powder material may be polystyrene that is dissolvable by styrene or gamma-butyrolactone.

[0079] The first active ingredient may be a (methyl)acrylate-based monomer, and the powder material may be poly(methyl)acrylate, cellulose, modified cellulose, hydroxyl-containing polyvinyl alcohol, polyester, polyurethane, modified polyamide, etc., which is dissolved by the (methyl)acrylate-based monomer.

[0080] The first active ingredient may be acryloylmorpholine, and the powder material may be polyurethane, cellulose, modified cellulose, hydroxyl-containing polyvinyl alcohol, etc., which are partially soluble by acryloylmorpholine.

[0081] The first active ingredient may be epichlorohydrin, an epoxy diluent, hydroxyethylacrylamide, and the powder material may be polycarbonate, polyamide, modified polyamide, cellulose ester, cellulose ether, etc., which can be dissolved by epichlorohydrin or an epoxy diluent or hydroxyethylacrylamide.

[0082] The first active ingredient may be gamma-butyrolactone, and the powder material may be polyacrylonitrile, acetate fiber, polymethylmethacrylate, polyvinylfluoride, polystyrene, etc., which are soluble by gamma-butyrolactone.

[0083] The first active ingredient may be ε-caprolactone and the powder material may be a chlorinated polyolefin, polyurethane, etc. that is soluble by ε-caprolactone.

[0084] In addition, the first liquid material may include a second active ingredient having an active group, and the second active ingredient does not dissolve the powder material, i.e., the second active ingredient does not completely dissolve the powder material. Optionally, the second active ingredient may undergo a polymerization reaction by itself or may participate in a polymerization reaction together with the first active ingredient.

[0085] In this embodiment, when the total weight of the first liquid material is 100%, the weight ratio of the second active component in the first liquid material is 5% to 90%. For example, it may be 5%, 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90%, and of course, the weight ratio can be proportional to the actual usage situation, and is not limited in this specification. Preferably, the weight ratio of the second active component in the first liquid material is 20% to 70%. By controlling the ratio of the second active component in the first liquid material, the second active component forms a performance complement with the first active component, on the premise that the first active component is ensured to dissolve the powder material, and as a result, the three-dimensional object has higher properties such as reduced shrinkage than when only the first active component is contained.

[0086] In addition, during printing of the three-dimensional object, the second active component can be filled into the voids between particles of the powder material or inside the powder particles to reduce the porosity of the molded object and increase the molding density of the object. In addition, the second active component can also form a performance complement with the first active component, so that the three-dimensional object has higher properties than if it contained only the first active component.

[0087] The second active ingredient includes at least one of isobornyl acrylate, isobornyl methacrylate, dodecyl acrylate, dodecyl methacrylate, caprolactone acrylate, cyclic trimethylolpropane formal acrylate, a carbon-carbon double bond-containing prepolymer, an epoxy group-containing prepolymer, a monomer that promotes ring-opening polymerization of an epoxy group, a prepolymer that promotes ring-opening polymerization of an epoxy group, a solid cyclic lactone, and a cyclic amide-based compound.

[0088] For example, the carbon-carbon double bond-containing prepolymer may be, for example, an epoxy or (modified) acrylate-based prepolymer, a polyester acrylate-based prepolymer, a polyurethane acrylate-based prepolymer, a pure acrylate-based prepolymer, etc. The epoxy group-containing prepolymer may be, for example, epoxy resin E-51, epoxy resin E-41, etc., and the cyclic lactone may be, for example, lactide, glycolide, etc., and the cyclic lactone itself is a solid and has poor solubility. Some compounds having a cyclic acetal structure, such as triformaldehyde, are solid themselves. (Methyl)acrylate-based monomers have different abilities to dissolve polymers due to differences in their structures, and for example, isobornyl acrylate, isobornyl methacrylate, dodecyl acrylate, dodecyl methacrylate, cyclic trimethylolpropane formal acrylate, etc. have poor effects of dissolving polyurethane-based powders and basically do not dissolve them.

[0089] Furthermore, the first liquid material further includes a first auxiliary, and the first auxiliary includes at least one of a high-temperature initiator, a leveling agent, an antifoaming agent, a polymerization inhibitor, an antioxidant, a plasticizer, a dispersant, and a colorant. Specifically, when the total weight of the first liquid material is 100%, the weight ratio of the first auxiliary in the liquid material is 0.1% to 30%, specifically, it may be 0.1%, 1%, 5%, 10%, 15%, 19.5%, 24.5%, 27%, or 30%, etc., and of course, the weight ratio can be proportional according to the actual usage situation, and is not limited in this specification.

[0090] Exemplarily, the weight percentage of the high-temperature initiator in the first liquid material is 0% to 10%, specifically, 0%, 0.1%, 1%, 3.4%, 5.7%, 6.0%, 7.5%, 8.5%, 9.7%, or 10%, and the weight percentage of the leveling agent in the first liquid material is 0.01% to 3%, specifically, 0.01%, 0.05%, 0.1%, 0.5%, 1.2%, 1.8%, 2.1%, 2.5%, 2.7%, 3.0%, 3.5 ... %, or 3%, etc., the weight ratio of the defoaming agent in the first liquid material is 0.01% to 3%, specifically, 0.01%, 0.05%, 0.1%, 0.5%, 1.2%, 1.8%, 2.1%, 2.5%, 2.7%, or 3%, etc., and the weight ratio of the polymerization inhibitor in the first liquid material is 0.05% to 3%, specifically, 0.05%, 0.1%, 0.5%, 1.2%, 1.8%, 2.1% , 2.5%, 2.7%, or 3%, etc., the weight percentage of the antioxidant in the first liquid material may be 0.05% to 3%, specifically, 0.05%, 0.1%, 0.5%, 1.2%, 1.8%, 2.1%, 2.5%, 2.7%, or 3%, etc., the weight percentage of the plasticizer in the first liquid material may be 0% to 25%, specifically, 0%, 1%, 5%, 10%, 15%, 17.5%, 20%, or may be 25%, the weight percentage of the dispersant in the first liquid material is 0% to 5%, specifically, 0%, 0.1%, 1%, 1.4%, 1.7%, 2.0%, 2.5%, 3.5%, 4.2%, or 5%, and the weight percentage of the pigment or dye in the first liquid material is 0 to 10%, specifically, 0%, 0.1%, 1%, 2%, 4%, 5%, 6%, 7%, 9%, or 10%, etc. Of course, the weight percentage of each of the above components in the first liquid material can be proportional depending on the actual usage situation, and is not limited in this specification.

[0091] In addition, since the high-temperature initiator does not significantly initiate the active components of the first liquid material, such as the first active component or the first active component and the second active component, under room temperature conditions, the first liquid material containing the high-temperature initiator is relatively stable at room temperature and can be stored for 3 to 6 months or even longer. In this application, the high-temperature initiator is preferably defined as an initiator having a 1-hour half-life of greater than 120°C. Although the high-temperature initiator has a good initiation effect under high-temperature environment, the allowable temperature of some polymer powder materials is often lower than the decomposition temperature of the high-temperature initiator, so there is a need for an initiation accelerator that promotes the initiation effect of the high-temperature initiator at a low temperature.

[0092] Specifically, the high temperature initiator may be at least one selected from tert-amyl peroxypivalate, tert-amyl perbenzoate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butyl peroxybenzoate, ethyl 3,3-bisbutanoate, ethyl 3,3-bis(tert-butylperoxy)butanoate, ethyl 3,3-bis(tert-amylperoxy)butanoate, dicumyl peroxide, di-tert-pentyl peroxide, di-tert-butyl peroxide, tert-amyl peroxide, tert-butyl peroxide, cumene hydroperoxide, and the like.

[0093] The leveling agent plays a role of improving the fluidity of the first liquid material and the wettability of the powder material, while adjusting the surface tension of the first liquid material to enable normal printing. In the present application, as long as the leveling agent used can meet the above performance requirements, there is no limitation on the type of leveling agent to be selected, and it may be, for example, BYK333, BYK377, BYK1798, BYK-UV3530, BYK-UV3575, BYK-UV3535, etc. of BYK Company, TEGO wet 500, TEGO wet 270, TEGO Glide450, TEGO RAD 2010, TEGO RAD 2011, TEGO RAD 2100, TEGO RAD 2200, etc. of TEGO brand.

[0094] The antifoaming agent plays a role in suppressing, reducing, and removing bubbles in liquid materials. In the present application, as long as the antifoaming agent used can achieve the above-mentioned effects, there is no limitation on the specific antifoaming agent to be selected, and examples thereof include BYK055, BYK088, BYK020, BYK025, etc. of BYK Company, TEGO Airex 920, TEGO Airex 921, TEGO Airex 986, TEGO Foamex 810, TEGO Foamex N, etc. of TEGO brand, and Efka 7081, Efka 7082, etc. of Efka brand.

[0095] The polymerization inhibitor may be one that improves the stability of the active ingredient of the first liquid material at high temperatures, or one that prevents the active ingredient from causing a polymerization reaction under a non-printing state and improves the storage stability of the liquid material. For example, it may be hydroquinone, 4-methoxyphenol, 1,4-benzoquinone, 2-tert-butylhydroquinone, phenothiazine, etc., GENORAD*16, GENORAD*18, GENORAD*20, GENORAD*22, etc. from RAHN, Tinuvin234, Tinuvin770, Irganox245 from BASF, S100, Cytec130, etc. from Cytec, Irgastab UV10, Irgastab UV22, etc. from Ciba Specialty Chemicals.

[0096] The antioxidant mainly plays a role in retarding or inhibiting the oxidation of the polymer, and may be, for example, 2,6-di-tert-butyl-4-methylphenol, β-tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid] pentaerythritol ester, β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionic acid-n-octadecanol ester, 1,1,3-tris(2-methyl-4-hydroxyl-5-tert-butylphenyl)butane, 4-[(4,6-dioctylthio-1,3,5-triazin-2-yl)amino]-2,6-di-tert-butyl-phenol, dilauryl thiodipropionate, tris(nonylphenyl)phosphite, triphenylphosphite, 2-mercaptobenzimidazole, and the like.

[0097] The plasticizer mainly serves to improve the toughness of the finished three-dimensional object, and may be, for example, dioctyl phthalate, benzyl butyl phthalate, diisononyl phthalate, diisodecyl phthalate, diethyl adipate, dibutyl adipate, diisobutyl adipate, bis(2-butoxyethyl) adipate, bis(2-ethylhexyl) adipate, triethyl citrate, acetyl triethyl citrate, tributyl citrate, or acetyl tributyl citrate.

[0098] The dispersant mainly plays a role of enhancing and improving the dispersion stability of the colorant.For example, there is no restriction on the specific dispersant to be selected, and there are many products currently on the market, but it may be BYK102, BYK108, BYK110, BYK180, BYK9133, BYK9076, BYK9131, TEGO Dispers655, Dispers675, Dispers688, Dispers750, Dispers670, etc.

[0099] In the present application, when neither the first liquid material nor the second liquid material contains a colorant, the polymer formed by the polymerization reaction of the active ingredient and the powder material can be mixed at the molecular level, and then a colorless or light-colored transparent three-dimensional object can be easily obtained.

[0100] Coloring of the three-dimensional object can be achieved if the first liquid material and / or the second liquid material contains a colorant, which may be a dye or a pigment.

[0101] Specifically, the pigment is one or more selected from CI Pigment White 6, CI Pigment Red 3, CI Pigment Red 5, CI Pigment Red 7, CI Pigment Red 9, CI Pigment Red 12, CI Pigment Red 13, CI Pigment Red 21, CI Pigment Red 31, CI Pigment Red 49:1, CI Pigment Red 58:1, CI Pigment Red 175; CI Pigment Yellow 63, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 16, CI Pigment Yellow 83; CI Pigment Blue 1, CI Pigment Blue 10, CI Pigment Blue B, Phthalocyanine Blue BX, Phthalocyanine Blue BS, CI Pigment Blue 61:1, and the like.

[0102] The dyes are specifically CI Acid Red 37, CI Acid Red 89 (Weak Acid Red 3B, 2BS), CI Acid Red 145 (Weak Acid Bright Red GL), CI Acid Orange 67 (Weak Acid Yellow RXL), CI Acid Orange 116 (Acid Orange AGT), CI Acid Orange 156 (Weak Acid Orange 3G), CI Acid Yellow 42 (Weak Acid Yellow Rs, Acid Yellow R), CI Acid Yellow 49 (Acid Yellow GR200), CI Acid Blue 277, CI Acid Blue 344, CI Acid Blue 350, CI Acid Blue 9 (Brilliant Blue FCF), CI Green 17, CI Acid Green 28, CI Acid Green 41, CI Acid Green 81, It may be selected from CI Acid Violet 17 (Acid Violet 4BNS), CI Acid Violet 54 (Weak Acid Brilliant Red 10B), CI Acid Violet 48, CI Acid Brown 75, CI Acid Brown 98, CI Acid Brown 165, CI Acid Brown 348, CI Acid Brown 349, CI Acid Black 26, CI Acid Black 63, CI Acid Black 172, CI Acid Black 194, CI Acid Black 210, CI Acid Black 234, CI Acid Black 235, CI Acid Black 242, Orasol Red 395 / BL, and the like.

[0103] In the second liquid material of the present application, the second auxiliary is for accelerating the polymerization reaction of the first liquid material, specifically for initiating or catalyzing the polymerization reaction of the active component of the first liquid material. Specifically, the second auxiliary includes at least one of an initiator, an initiation accelerator, and a catalyst, and when the total weight of the second liquid material is 100%, the weight ratio of the second auxiliary in the second liquid material is 0.1% to 40%, specifically, it may be 0.1%, 1%, 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, or of course, it may be other values ​​within the above range, and is not limited in the present specification.

[0104] The initiator is selected from water-soluble or water-dispersible initiators, and may be azodiisobutylamidine hydrochloride, azodiisobutylimidazoline salt, azodicyanovaleric acid, azodiisopropylimidazoline, sodium persulfate, ammonium persulfate, potassium persulfate, azo-containing polymethacrylate, azo-containing self-emulsifying polyurethane, or some aqueous dispersion of organic peroxide (reference: Zhigang Tei. PVC initiator-aqueous dispersion of organic peroxide [J] Polyvinyl chloride, 1995, 2nd period).

[0105] The initiator accelerator can be selected from some of the water-soluble initiator accelerators such as ferrous lactate, dimethylaniline, tetramethylthiourea, dimethylthiourea, etc. When the first liquid material contains a high-temperature initiator, the initiator accelerator is added to the second liquid material to reduce the polymerization temperature of the first liquid material, thereby achieving the effect of improving strength.

[0106] The catalyst may be benzyltriethylammonium chloride, triethylamine, triethanolamine, methyl fluorosulfonate, ethyl fluorosulfonate, methyl nitrobenzenesulfonate, methyl methanesulfonate, and the like.

[0107] The second liquid material contains water, and the weight ratio of water in the second liquid material is 30% to 90%, specifically, it may be 30%, 35%, 40%, 45%, 50%, 55%, 60%, 80%, 85%, 90%, and of course, it may be other values ​​within the above range, and is not limited in this specification. The purpose of making the second liquid material contain water is mainly that when the second liquid material is sprayed in the non-molding area, the water can lower the temperature of the powder material in the non-molding area, and in the process of evaporating the water, the evaporated moisture takes away the temperature of the powder material in the non-molding area, thereby preventing the powder material in the non-molding area from melting and / or being dissolved by the first liquid material, adhering to the surface of the molded object, and affecting the surface accuracy of the object, and further, the use of water is less costly and more environmentally friendly than the use of other volatile solvents.

[0108] The second liquid material contains a powdered release agent, and the weight ratio of the powdered release agent in the second liquid material is 0.01% to 10%. The powdered release agent is at least one selected from a silicon-containing water-soluble release agent, a silicon-containing water-dispersible release agent, a fluorine-containing water-soluble release agent, and a fluorine-containing water-dispersible release agent.

[0109] Specifically, the silicon-containing water-soluble release agent or the silicon-containing water-dispersible release agent may be selected from silicone oil emulsions, and the fluorine-containing water-soluble release agent or the fluorine-containing water-dispersible release agent may be selected from fluorine-containing nonionic surfactants or fluorine-containing anionic surfactants.

[0110] Illustratively, the silicone oil emulsion may be a mixture containing a polysiloxane polymer with water as a dispersant.

[0111] The fluorine-containing nonionic surfactant may be a fluorinated aliphatic alcohol-containing polyoxyethylene ether, a fluorinated phenol-containing polyoxyethylene ether, a fluorinated carboxylic acid-containing polyoxyethylene ester, a fluorinated alkylsulfonylamide-containing polyoxyethylene ether, or a fluorinated mercaptan-containing polyoxyethylene ether.

[0112] The fluorine-containing anionic surfactant may be a fluorine-containing carboxylate, a fluorine-containing sulfonate, a fluorine-containing phosphate, or the like.

[0113] The three-dimensional printing material provided by this embodiment is applied to printing three-dimensional objects, and during printing of the three-dimensional object, the amount of the second liquid material in a unit volume of the molding area is controlled to be less than the amount of the second liquid material in a unit volume of the non-molding area, and the second liquid material in the molding area mainly plays a role of promoting the polymerization reaction of the first liquid material to form a polymer, and the second liquid material in the non-molding area mainly plays a role of reducing the temperature of the powder material in the non-molding area, preventing the first liquid material in the molding area from diffusing into the non-molding area, and improving the surface accuracy of the formed three-dimensional object.

[0114] The powder release agent contained in the second liquid material serves to reduce the surface tension of the powder surface. Furthermore, the content of the second liquid material injected per unit volume of the molding area is less than the amount of the second liquid material injected per unit volume of the surrounding non-molding area. Therefore, the surface tension of the powder surface or between the powder particles in the non-molding area surrounding the molding area is less than the surface tension of the powder surface or between the powder particles in the molding area, and the first liquid material in the molding area is less likely to spread to the edges.

[0115] The present application controls the weight percentage of the powder release agent to 0.01%-10%, specifically, it may be 0.01%, 0.05%, 0.08%, 0.1%, 0.5%, 0.9%, 1.1%, 2.6%, 3.9%, 4%, 5%, 6.6%, 7.9%, 9.9%, 10%, or other values ​​within the above range, and is not limited in the present specification. After many tests, it was found that when the weight percentage of the powder release agent is less than 0.01%, it cannot effectively prevent the first liquid material in the molding area from diffusing to the non-molding area. When the weight percentage of the powder release agent is more than 10%, the present application found that some powder release agents exceed a certain content, which too much affects the penetration of the first liquid material into the powder material layer and too much suppresses the effect of the first liquid material in the molding area diffusing to the edge, which is disadvantageous to improving the surface precision of the edge of the molding area.

[0116] The second liquid material contains a release agent, and the weight ratio of the release agent in the second liquid material is 1% to 30%, specifically, it may be 1%, 2%, 5%, 8%, 12%, 15%, 18%, 19%, 22%, 24%, 25%, 28%, 29%, 30%, or other values ​​within the above range, and is not limited in this specification. The release agent is selected from water-soluble polymers and / or water-dispersible polymers having a glass transition temperature lower than 40°C, and is preferably a water-soluble polymer or water-dispersible polymer having a glass transition temperature lower than 0°C in order to make it easier to break during sandblasting treatment.

[0117] Specifically, the water-soluble polymer or water-dispersible polymer is at least one selected from a polyether resin, a polyester resin, a poly(methyl)acrylate resin, and a polyurethane resin.

[0118] It will be appreciated that when a second liquid material is added to the non-molded areas of the powder material, the release agent causes the powder material in the non-molded areas at the edges of the molded area to adhere, the release agent helps to release the powder material in the non-molded areas from the substantial portion formed in the molded area, and contributes to separating the recovered powder material from the powder in other non-molded areas.

[0119] The second liquid material contains a hydrocarbon chain surfactant, and the weight percentage of the hydrocarbon chain surfactant in the second liquid material is 0.1% to 10%, specifically, 0.1%, 0.5%, 0.9%, 1.1%, 2.6%, 3.9%, 4%, 5%, 6.6%, 7.9%, 9.9%, 10%, or other values ​​within the above range, and is not limited herein. Adding an appropriate amount of a hydrocarbon chain surfactant to the second liquid material is advantageous for dissolving or dispersing the second auxiliary, powder release agent, and release agent in water, and is advantageous for forming a homogeneous liquid.

[0120] Specifically, the hydrocarbon chain surfactant is one or more selected from fatty alcohol polyoxyethylene ethers, sodium alkyl sulfonates, sodium alkylbenzene sulfonates, sodium alkyl sulfates, sodium alkyl succinic acid sulfonates, sodium sulfamate, polyethers, and polyoxyethylene polyoxypropylene ether block copolymers.

[0121] In another alternative embodiment, the second liquid material further includes a co-solvent, and the weight ratio of the co-solvent in the second liquid material is 0.05% to 30%, specifically, 0.05%, 0.1%, 1%, 2%, 5%, 8%, 12%, 15%, 18%, 19%, 22%, 24%, 25%, 28%, 29%, 30%, or other values ​​within the above range, and is not limited herein. The co-solvent is at least one selected from alcohols, alcohol ethers, amides, pyrrolidones, organic acids, and organic salts. Adding an appropriate amount of co-solvent to the second liquid material can effectively increase the solubility of the second assistant, powder release agent, release agent, etc. in the second liquid material, and further improve the surface precision of the formed three-dimensional object.

[0122] Specifically, the alcohol-based agent may be at least one of ethylene glycol, propylene glycol, glycerol, butanediol, diethylene glycol, etc. The alcohol ether-based agent may be at least one of polyethylene glycol 200, polyethylene glycol 400, propylene glycol ether, etc. The amide-based agent may be at least one of urea, acetamide, etc. The pyrrolidone-based agent may be at least one of pyrrolidone, hydroxyethylpyrrolidone, methylpyrrolidone, etc. The organic acid-based agent may be at least one of paraaminobenzoic acid, benzenesulfonic acid, ascorbic acid, etc., and the organic salt-based agent may be at least one of sodium benzoate, sodium salicylate, etc.

[0123] FIG. 1 is a flow chart of a method for printing a three-dimensional object provided by an embodiment of the present application. As shown in FIG. 1, in another aspect, the present application provides a method for printing a three-dimensional object, comprising the steps of: In step S10, a powder material is used to form a powder material layer including formed and non-formed regions. In step S20, according to the layer printing data, a first liquid material and a second liquid material that promotes a polymerization reaction of the first liquid material to form a layer solid portion of the three-dimensional object are added in a first ratio within the molding area of ​​the powder material layer. In step S30, the first liquid material and the second liquid material are added in a second ratio in the non-molding area of ​​the powder material layer according to the layer print data to form a layer protection portion of the three-dimensional object, the first ratio being greater than the second ratio, such that the amount of the second liquid material in a unit volume of the molding area is less than the amount of the second liquid material in a unit volume of the at least partial non-molding area, and the amount of the first liquid material in a unit volume of the molding area is greater than the amount of the first liquid material in a unit volume of the at least partial non-molding area.

[0124] In the above solution, by storing the first liquid material and the second liquid material separately and adding them in different composition ratios to the molded and non-molded areas of the powder material layer, it is not only useful for increasing the storage stability of the liquid material and improving the fluency of inkjet printing of the liquid material, but also for lowering the temperature of the non-molded area and reducing the effect of the first liquid material on the powder material in the non-molded area, thereby reducing the difficulty of post-processing of the printed three-dimensional object, especially the difficulty of post-processing of the surface of the three-dimensional object, and as a result, improving the surface accuracy of the printed product.

[0125] In the present application, the powder material is the above-mentioned metal powder material or organic polymer powder material, and when the powder material is an organic polymer powder material, the organic polymer powder material may be insoluble in the first liquid material and at the same time insoluble in the second liquid material, or at least a portion of the organic polymer powder material may be dissolved by the first liquid material but not dissolved by the second liquid material, which specifically depends on the specific configuration of the first liquid material.

[0126] Specifically, when the powder material is not dissolved by the first liquid material and at the same time not dissolved by the second liquid material, the reaction mechanism of the embodiment in this case is that the second liquid material promotes the polymerization reaction of the first liquid material in the forming region of the powder material layer, and the polymer formed by the reaction encapsulates the powder material in contact with the first liquid material to form the layer solid part of the three-dimensional object. By controlling the magnitude of the second ratio in the non-forming region of the powder material layer, the first liquid material in the non-forming region is diluted in content or concentration, and an effective polymerization reaction to form a polymer does not occur, or a small amount of free polymer formed by the polymerization reaction of the first liquid material in the non-forming region cannot effectively encapsulate the powder material, but can form particles larger than the original powder material particles. In the non-molded area of ​​the powder material layer, the second liquid material mainly serves to reduce the temperature of the powder material in the non-molded area, and / or at the same time prevent the first liquid material in the molded area from diffusing into the non-molded area to form a layer protection part of the three-dimensional object, thereby improving the surface accuracy of the three-dimensional object and reducing the ratio of the first liquid material in the non-molded area, so that the polymer cannot effectively encapsulate the powder material but can form particles larger than the original powder particles, which is beneficial to sandblasting and powder recovery and screening, and reduces the difficulty of post-processing.

[0127] When at least a portion of the powder material is dissolved by the first liquid material but not by the second liquid material, the reaction mechanism of this embodiment is that in the molding area of ​​the powder material layer, the first liquid material dissolves the powder material in contact with this liquid material, and the second liquid material promotes the polymerization reaction of the first liquid material to form a polymer to form the layer solid part of the three-dimensional object, and the formed polymer mixes with the dissolved powder material, in particular, mixes with the dissolved powder material at the molecular level to form a polymer alloy, and the powder materials, the powder materials and the formed polymer, and the printed layers all have good connection effects, resulting in a "sea-island structure" or homogeneous structure, which can improve the mechanical strength of the three-dimensional object. By controlling the magnitude of the second ratio in the non-molding region of the powder material layer, the first liquid material has a content or concentration that is not enough to dissolve the powder material in contact with the liquid material, but can form particles larger than the original powder material particles and the first liquid material cannot effectively polymerize to form a polymer, or the first liquid material can polymerize to form a small amount of polymer that is free in the non-molding region. In the non-molding region of the powder material layer, the second liquid material mainly plays a role in reducing the temperature of the powder material in the non-molding region and / or at the same time preventing the first liquid material in the molding region from diffusing into the non-molding region to form a layer protection part of the three-dimensional object, thereby improving the surface accuracy of the three-dimensional object and reducing the difficulty of post-processing.

[0128] When the first and second liquid materials are added to the powder material layer, the liquid materials can quickly penetrate into the powder material layer through the gaps and retain a part of them on the surface layer, and further wet the surface of the powder material in a selected area to at least partially dissolve the powder material. Note that dissolution in each embodiment of the present application refers to all possible cases except for the case where the powder material is not completely dissolved.

[0129] It should be noted that the step numbers in the flowchart of the present application do not indicate the order during printing of a three-dimensional object; in the actual printing process, step S20 may be performed before step S30, after step S30, or simultaneously with step S30; this is related to the printing method and / or the shape of the object to be printed, and only some cases are described in the specification of the present application, not all of them.

[0130] Please refer to Figure 2. Hereinafter, a detailed description will be given with reference to specific embodiments.

[0131] Before step S10, the method further includes step S01; In step S01, a digital model of a three-dimensional object is acquired, the digital model of the three-dimensional object is sliced ​​into layers, a plurality of slice layers and slice layer image data are acquired, and layer printing data including layer printing data of a molding area and layer printing data of a non-molding area is generated according to the slice layer image data.

[0132] In a particular implementation, raw data of a three-dimensional object is obtained by scanning, and three-dimensional modeling is performed to obtain a digital model of the three-dimensional object, or a three-dimensional object model is constructed by design to obtain a digital model of the three-dimensional object, and the data format of the digital model is converted into a format that can be recognized by slicer software, such as STL format, PLY format, WRL format, etc., and the slicer software is used to slice and layer the model to obtain sliced ​​layer image data, and the layer image data is processed to obtain layer printing data representing the object, including layer printing data of a molding area indicating object shape information and layer printing data of a non-molding area indicating the periphery of the object.

[0133] In the present application, the shape of the three-dimensional object to be printed is not limited, and may be an object of any shape. Figure 3a is a structural schematic diagram of a three-dimensional object to be printed provided by an embodiment of the present application, and as shown in Figure 3a, in a specific embodiment, the three-dimensional object 1 to be printed may be, for example, a cylinder, and after the three-dimensional object 1 to be printed is sliced ​​and layered, multiple slice layers of the three-dimensional object are obtained, and the layer substance part can be printed and formed according to the layer printing data of the molding area 1n in the slice layer.

[0134] In step S10, a powder material is used to form a powder material layer including formed and non-formed regions.

[0135] In the actual printing process, the molding area 1n of the powder material layer forms the substantial part of the three-dimensional object, i.e., the outline of the three-dimensional object to be printed and the area within the outline, and the non-molding area is the area other than the outline of the three-dimensional object to be printed. In this embodiment, a protection part of the three-dimensional object is formed in the non-molding area of ​​the powder material layer.

[0136] 3b is a structural schematic diagram of a powder material layer provided by an embodiment of the present application, and as shown in FIG. 3b, the area other than the molded area 1n on the powder material layer L0 is a non-molded area, and the area 1n' is at least a part of the non-molded area, located around the molded area 1n, and is called a layer protection part. In other embodiments, the area 1n' may be a non-molded area.

[0137] The powder material used in this embodiment is the same as the three-dimensional printing material described above, and will not be described again here. The thickness of the formed 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, 500 μm, or other values ​​within the above range, and is not limited herein. The thickness of the powder material layer is preferably 50 μm to 150 μm. It should be understood that when the thickness of the powder material layer is thin, an object with high resolution can be formed, but the time required to manufacture the object is significantly longer and the manufacturing cost increases, while when the thickness of the powder material layer is thick, the time for the liquid material to penetrate the powder material is longer, and the resolution of the object formed by manufacturing is reduced, making it difficult to meet expectations.

[0138] In some embodiments, after step S10 and before step S201, the printing method further includes step S11: In step S11, the powder material layer is preheated.

[0139] It will be understood that thermal energy is supplied to the formed powder material layer to preheat the powder material, and the preheating temperature is 5°C to 100°C lower than the melting point or melting temperature of the powder material, and that by preheating the powder material, the polymerization reaction of the first liquid material that is subsequently added to the molding area can be effectively promoted, preventing the first liquid material in the molding area from diffusing to the non-molding area and affecting the surface accuracy of the molded product, and / or promoting the evaporation of a portion of the components (e.g., water) in the second liquid material that is subsequently added to the molding area, increasing the concentration of the auxiliary agent of the second liquid material in the molding area, and further accelerating the rate of the polymerization reaction of the first liquid material.

[0140] In some embodiments, the preheating energy includes at least one of radiation energy and thermal energy, and specifically, preheating can be performed by infrared irradiation, visible light irradiation, or the like.

[0141] In order to effectively improve the inkjet printing efficiency, the first liquid material and the second liquid material can be inkjet printed in the same scanning direction during printing.

[0142] A specific implementation of step S20 may be step S201, In step S201, in the same scanning direction, a first liquid material and a second liquid material that promotes a polymerization reaction of the first liquid material to form a layer solid portion of the three-dimensional object are added in a first ratio within the molding area of ​​the powder material layer according to the layer printing data of the molding area.

[0143] In some embodiments, storing the first and second liquid materials separately and adding them in different composition ratios to the molded and non-molded areas of the powder material layer not only enhances the storage stability of the liquid materials, but also helps to improve the inkjet printing fluency of the liquid materials.

[0144] In an embodiment of the present application, the first liquid material comprises a first active ingredient, the weight percentage of the first active ingredient in the first liquid material is 10% to 95%, and the first active ingredient at least partially dissolves the powder material.

[0145] Specifically, the first active component has an active group capable of participating in a polymerization reaction, and the active group includes at least one of a carbon-carbon double bond, a hydroxyl, a carboxyl, an ethylene sulfide group, a carbonate ester group, an epoxy group, a liquid cyclic lactone structure, and a cyclic acetal structure. The first active component may be at least one selected from a carbon-carbon double bond-containing monomer, a composition of a substance containing an epoxy group and a substance that promotes ring-opening polymerization of the epoxy group, a cyclic lactone, a thioheterocyclic compound, a carbonate ester compound, and a cyclic amide compound. Note that the first active component does not cause a polymerization reaction with the powder material. Specific examples can be referred to the above-mentioned description of the three-dimensional printing material, and will not be described here repeatedly.

[0146] The second liquid material comprises, by weight, 0.1%-40% of a second auxiliary, 30%-90% of water, 0.01%-10% of a powder release agent, 1%-30% of a stripping agent, and 0.1%-10% of a hydrocarbon chain surfactant, and the second auxiliary is for promoting the polymerization reaction of the first liquid material, specifically, for initiating or catalyzing the polymerization reaction of a first active component of the first liquid material.

[0147] Specifically, the second auxiliary agent includes at least one of an initiator, an initiation promoter, and a catalyst, the initiator is selected from a water-soluble or water-dispersible initiator, the initiation promoter can be selected from a part of a water-soluble initiation promoter, and the catalyst can be benzyltriethylammonium chloride, triethylamine, triethanolamine, methyl fluorosulfonate, ethyl fluorosulfonate, methyl nitrobenzenesulfonate, methyl methanesulfonate, etc.

[0148] The powder release agent is at least one selected from the group consisting of silicon-containing water-soluble release agents, silicon-containing water-dispersible release agents, fluorine-containing water-soluble release agents, and fluorine-containing water-dispersible release agents. Through repeated testing, it has been found that the powder release agent can reduce the surface tension of the powder surface, and an appropriate amount of the powder release agent can affect the penetration of the first liquid material into the powder material layer and inhibit the first liquid material in the molding area from diffusing to the edge, which is helpful in improving the surface precision of the edge of the molding area.

[0149] The release agent is selected from water-soluble polymers and / or water-dispersible polymers having a glass transition temperature lower than 40° C., and is preferably a water-soluble polymer or water-dispersible polymer having a glass transition temperature lower than 0° C. Specifically, the water-soluble polymer or water-dispersible polymer is at least one selected from polyether resins, polyester resins, poly(methyl)acrylate resins, and polyurethane resins. The release agent is useful for releasing the powder material in the non-molding region from the substantial portion formed in the molding region, and contributes to separating the recovered powder material from the powder in other non-molding regions.

[0150] The hydrocarbon chain surfactant is one or more selected from fatty alcohol polyoxyethylene ether, sodium alkyl sulfonate, sodium alkylbenzene sulfonate, sodium alkyl sulfate, sodium alkyl succinate sulfonate, sodium sulfamate, polyether, polyoxyethylene polyoxypropylene ether block copolymer. Adding an appropriate amount of a hydrocarbon chain surfactant to the second liquid material is favorable for dissolving or dispersing the second auxiliary, powder release agent, and release agent in water, and favorable for forming a homogeneous liquid.

[0151] The second liquid material contains water, and the main role of water is mainly that when the second liquid material is sprayed in the non-molded area, the water can reduce the temperature of the powder material in the non-molded area; and during the process of evaporating water, the evaporated moisture will take away the temperature of the powder material in the non-molded area, thereby preventing the powder material in the non-molded area from melting and / or being dissolved by the first liquid material and sticking to the surface of the molded object, thereby affecting the surface precision of the object; and furthermore, the use of water is less costly and more environmentally friendly than the use of other volatile solvents.

[0152] In another alternative embodiment, the second liquid material further contains a co-solvent with a weight ratio of 0.05% to 30%, and the co-solvent is at least one selected from alcohols, alcohol ethers, amides, pyrrolidones, organic acids, and organic salts. Adding an appropriate amount of co-solvent to the second liquid material can effectively increase the solubility of the second auxiliary agent, powder release agent, peeling agent, etc. in the second liquid material, and further improve the surface precision of the formed three-dimensional object.

[0153] Specifically, the first ratio is the ratio between the amount of the first liquid material added to the molding area of ​​the powder material layer and the amount of the second liquid material added. Note that the "amount" is a measure of how much the first liquid material and the second liquid material are present, and may be volume, weight, or number of ink droplets, and is not limited in the present application.

[0154] In a specific embodiment, the first ratio is the volume ratio of the first liquid material to the second liquid material, the first ratio is (1-10):1, the first ratio may be specifically 1:1, 2:1, 3:1, 5:1, 6:1, 7:1, 8:1, 10:1, etc., and in the molding area of ​​the powder material layer, the magnitude of the first ratio is controlled so that the second liquid material promotes the rapid polymerization reaction of the first liquid material, thereby obtaining a layer solid part of a three-dimensional object with a predetermined material performance. When the second liquid material is insufficient, the polymerization reaction of the first liquid material is slow and incomplete, and finally the strength of the three-dimensional object is reduced, and the first liquid material does not fully participate in the polymerization reaction to form a polymer, so that the excess first liquid material is easy to penetrate into the non-molding area, which affects the molding accuracy of the object. If there is an excess of the second liquid material, the second liquid material will tend to lower the temperature of the powder material in the molding area, slow down the rate of the polymerization reaction of the first liquid material and / or slow down the dissolution rate at which the first liquid material dissolves the powder material.

[0155] Accordingly, a specific implementation of step S30 may be step S301, In step S301, in the same scanning direction as step S201, a first liquid material and a second liquid material are added in a non-molded area of ​​the powder material layer in a second ratio according to the layer printing data of the non-molded area to form a layer protection portion of a three-dimensional object, wherein the first ratio is greater than the second ratio, and the amount of the second liquid material in a unit volume of the molding area is less than the amount of the second liquid material in a unit volume of at least the partial non-molded area, and the amount of the first liquid material in a unit volume of the molding area is greater than the amount of the first liquid material in a unit volume of at least the partial non-molded area.

[0156] The second ratio is a ratio between the amount of the first liquid material added to the non-molded area of ​​the powder material layer and the amount of the second liquid material added. In the present application, the first ratio is greater than the second ratio, i.e., when the first liquid material and the second liquid material are mixed, the ratio of the mixture occupied by the first liquid material in the first ratio is greater than the ratio of the mixture occupied by the first liquid material in the second ratio.

[0157] In a specific embodiment, the second ratio is a volume ratio of the first liquid material to the second liquid material, and the second ratio is (0 to 0.95):1. Specifically, the second ratio may be 0, 0.05:1, 0.1:1, 0.2:1, 0.5:1, 0.7:1, 0.8:1, 0.95:1, etc., and when the second ratio is 0, it means that only the second liquid material is added to the non-molding region of the powder material layer. In this case, the amount of the second liquid material added to the non-molding region only needs to satisfy that the amount of the second liquid material added per unit volume of the non-molding region is greater than the amount of the second liquid material added per unit volume of the molding region, and the second liquid material is mainly for lowering the temperature of the powder material in the non-molding region and / or preventing the first liquid material in the molding region from penetrating into the non-molding region, thereby improving the surface accuracy of the three-dimensional object to be formed.

[0158] When the second ratio is greater than 0, it means adding the first liquid material and the second liquid material in the non-molding region of the powder material layer, and the second liquid material is mainly for reducing the temperature of the powder material in the non-molding region, and / or using the second liquid material to reduce the concentration of the first liquid material in the non-molding region, thereby preventing the powder material in the non-molding region from being melted by high temperature and sticking to the surface of the three-dimensional object or being dissolved by the first liquid material, and / or preventing the first liquid material in the molding region from penetrating into the non-molding region, thereby improving the surface accuracy of the formed three-dimensional object. It should be understood that, since the amount of the second liquid material per unit volume of the non-molding region is greater than the amount of the second liquid material per unit volume of the molding region, the endothermic evaporation of a part of the components can reduce the temperature of the powder material in the non-molding region, prevent the powder material in the non-molding region from sticking to the surface of the molded three-dimensional object, and improve the surface accuracy of the three-dimensional object.

[0159] In a specific implementation process, the present application controls the amount of the first liquid material in the non-molded area of ​​the powder material layer, and makes the second ratio greater than 0.95:1, so that the second liquid material in the non-molded area promotes the polymerization reaction of the first liquid material, and the formed polymer has sufficient strength, and the polymer formed in the non-molded area will adhere to the surface of the object, reducing the surface accuracy of the formed three-dimensional object and increasing the difficulty of post-processing.

[0160] In the above embodiment, the amount of the second liquid material in the unit volume of the molding region is less than the amount of the second liquid material in the unit volume of the non-molding region. In the molding region, the second liquid material mainly plays the role of accelerating the polymerization reaction of the first liquid material to form a polymer, and when the polymer formed in the molding region is mixed with the dissolved powder material, especially when mixed with the dissolved powder material at the molecular level to form a polymer alloy, the mechanical strength of the three-dimensional object can be improved.

[0161] In the non-molding region, the second liquid material mainly serves to lower the temperature of the powder material in the non-molding region, and in the non-molding region, the second liquid material can also prevent the first liquid material in the molding region from diffusing into the non-molding region. Specifically, the content of the second liquid material injected per unit volume of the molding region is made smaller than the amount of the second liquid material injected per unit volume of the surrounding non-molding region, so that the surface tension of the powder surface or between the powder particles in the non-molding region surrounding the molding region becomes smaller than the surface tension of the powder surface or between the powder particles in the molding region due to the action of the powder release agent of the second liquid material, and the first liquid material in the molding region is less likely to diffuse to the periphery. That is, the first liquid material penetrates into the powder material in the non-molded area, making it difficult to dissolve the powder material in the non-molded area, which helps to reduce the effect of the first liquid material on the powder material in the non-molded area; in addition, the second liquid material contains water, and when a sufficient amount of water evaporates, it can take away the temperature of the powder material in the non-molded area, which helps to lower the temperature of the non-molded area and prevent the powder material in the non-molded area from sticking to the surface of the formed layer substance part (corresponding to the molding area) at a high temperature, thereby forming an interface between the formed layer substance part and the layer protection part without the layer protection part fusing with the layer substance part, thereby improving the surface accuracy of the formed three-dimensional object.

[0162] Furthermore, since the proportion of the first liquid material in the liquid material added in the non-molded area is low, and the polymer formed by the first liquid material cannot effectively encapsulate the powder material, particles larger than the original powder material particles can be formed, which contributes to sandblasting and recovery of the powder material, and reduces the difficulty of post-processing of the three-dimensional object obtained by printing, especially the difficulty of post-processing of the surface of the three-dimensional object, thereby improving the surface accuracy of the printed product.

[0163] 4a to 4e are schematic diagrams of the structure of the landing point of ink droplets when the first liquid material and the second liquid material provided by the embodiment of the present application are ejected in a predetermined ratio. As shown in FIG. 4a to 4e, in FIG. 4a, the x direction is the scanning direction of the print head, and the y direction is the stepping direction of the print head, and each small block represents the smallest printing unit of the printer, which is called a voxel in three-dimensional printing, and which is called a pixel in two-dimensional plane. Each dotted box in the figure represents a hybrid unit, and the first liquid material A and the second liquid material B are ejected in a ratio into the hybrid unit. For example, in the hybrid unit X1, the first liquid material A and the second liquid material B are ejected into different voxels respectively to be mixed in a volume ratio of 5:4. When the first liquid material A and the second liquid material B come into contact with each other, the second liquid material B will promote the polymerization reaction of the first liquid material A. Also, for example, in hybrid unit X2, the first liquid material A is mixed with the second liquid material B at a volume ratio of 1:1. For example, in hybrid unit X3, the first liquid material A is mixed with the second liquid material B at a volume ratio of 0.8:1. In this particular embodiment, the hybrid unit is an area where the first liquid material A and the second liquid material B can be sprayed at a predetermined ratio to be essentially uniformly mixed, and the actual size of the area is not limited herein.

[0164] During printing, the hybrid unit ejects the first liquid material and the second liquid material in a predetermined ratio. During printing of the layer solid portion of the three-dimensional object, the hybrid unit may be in a single form or may be combined with other forms of hybrid units, and is not limited herein.

[0165] FIG. 4b is another structural schematic diagram of the ink droplet landing point of the first liquid material and the second liquid material, where the x direction represents the scanning direction and the Z direction represents the ink droplet stacking direction. In this particular embodiment, the first liquid material A and the second liquid material B are ejected at the same voxel position in a predetermined ratio. During the inkjet printing shown in FIG. 4b, the first liquid material A and the second liquid material B are ejected at the same voxel position V in a volume ratio of 1:1.voxel Alternatively, during inkjet printing as shown in FIG. 4c, the first liquid material A and the second liquid material B are ejected at the same voxel position V voxel Alternatively, during inkjet printing as shown in FIG. 4d, the first liquid material A and the second liquid material B are ejected in a volume ratio of 2:1 at the same voxel position V voxel In the example shown in FIG. 4e, the first liquid material A and the second liquid material B are ejected at the same voxel position V in a 1:1 volume ratio, and the ink droplets are overlapped in the Z direction such that the volume of one ink droplet of the first liquid material A is twice the volume of one ink droplet of the second liquid material B at the same voxel position V. Alternatively, as shown in FIG. 4e, the x direction is the printhead scan direction and the y direction is the printhead step direction, and the first liquid material A and the second liquid material B are ejected at the same voxel position V in a 1:1 volume ratio, and the ink droplets are overlapped in the Z direction such that the volume of one ink droplet of the first liquid material A is twice the volume of one ink droplet of the second liquid material B at the same voxel position V. voxel The ink droplets are ejected in a predetermined ratio to the molding area and the non-molding area, and the ink droplets are arranged on the horizontal plane of the same voxel. In the present application, the first liquid material and the second liquid material are ejected in a predetermined ratio to the molding area and the non-molding area, and the ink droplet falling method may be a combination of the above various methods and is not limited in the present specification.

[0166] Since the powder material in the non-molded areas needs to be removed from around the target object after the printing of the three-dimensional object is completed, the present application preferably reduces the range of the non-molded areas onto which the liquid material is sprayed in order to increase the recycling rate of the powder material.

[0167] In this embodiment, the width d of the layer protection part is equal to or larger than the minimum diameter of the droplets of the first and second liquid materials added while ensuring that the layer protection part fulfills the above-mentioned role. For example, when the minimum droplet diameter during inkjet is 10 um, d in this embodiment is equal to or larger than 10 um.

[0168] In another optional embodiment, the amount of the second liquid material in a unit volume of the non-molding region gradually decreases along the direction of the region 1n' in the non-molding region away from the molding region, thereby reducing the amount of the second liquid material jetted into the non-molding region and reducing the printing cost of the three-dimensional object.

[0169] In each specific embodiment of the present application, in order to increase the strength of the formed three-dimensional object, reduce the possibility that the powder material in the non-molded area will stick to the surface of the three-dimensional object formed by printing, improve the possibility of the powder material in the non-molded area sticking to the surface of the three-dimensional object, and enable the formation of a clear interface between the layer solid portion and the layer protection portion of the three-dimensional object, the amount of the second liquid material in a unit volume of the molding area is limited to be less than the amount of the second liquid material in a unit volume of at least a partial non-molded area, and the amount of the first liquid material in a unit volume of the molding area is limited to be greater than the amount of the first liquid material in a unit volume of at least a partial non-molded area.

[0170] Furthermore, after steps S20 and S30, more specifically, after performing steps S201 and S301, the printing method further includes a step S40 of heating the powder material layer to which the second liquid material has been added.

[0171] Heat energy is supplied to the powder material layer to which the second liquid material is added to heat the powder material layer to which the second liquid material is added, and the temperature of the heating is higher than 70° C. and lower than the melting point or melting temperature of the powder material by 5° C. or more. In this specific embodiment, it is understood that by heating the powder material layer to which the second liquid material is added, the polymerization reaction of the first liquid material in the molding region can be further promoted to prevent the first liquid material in the molding region from diffusing to the non-molding region and affecting the surface accuracy of the molded product, and / or the evaporation of a part of the components of the second liquid material (e.g., evaporation of water) can be promoted, and the concentration of the second auxiliary agent of the second liquid material in the molding region can be increased to further accelerate the rate of the polymerization reaction of the first liquid material, and the amount of the second liquid material per unit volume of the non-molding region is greater than the amount of the second liquid material per unit volume of the molding region, so that the temperature of the powder material in the non-molding region can be effectively reduced by the endothermic evaporation of a part of the components, and the powder material in the non-molding region can be prevented from sticking to the surface of the molded three-dimensional object, and the surface accuracy of the three-dimensional object can be improved.

[0172] In some specific embodiments, the heating energy includes at least one of radiation energy and thermal energy, and specifically, heating can be performed by infrared irradiation, visible light irradiation, or the like.

[0173] During the three-dimensional object printing, after step S40, the printing method further includes step S50: In step S50, it is determined whether the current molding layer of the three-dimensional object is the last layer; if not, the above steps from forming the powder material layer to forming the molding layer are repeatedly performed, and the obtained multiple molding layers are superimposed layer by layer to form the three-dimensional object.

[0174] It should be understood that at least one slice layer is obtained by slicing and layering the digital model of the three-dimensional object, and during the three-dimensional object printing, each formed molding layer needs to be overlapped layer by layer until the printing of all slice layers is completed and the target three-dimensional object is formed, otherwise, according to the layer printing data, it is necessary to repeatedly form a powder material layer and spray the first liquid material and the second liquid material to form a layer solid portion and a layer protection portion, and the layer solid portion and the layer protection portion constitute a molding layer and are overlapped layer by layer to form the three-dimensional object.

[0175] During the printing of the three-dimensional object, the second liquid material is added to the molding area to accelerate the polymerization reaction of the first liquid material and the first liquid material can dissolve at least a portion of the powder material to form a layer solid part of the three-dimensional object. The second liquid material in the non-molding area does not accelerate or accelerates the polymerization reaction of the first liquid material slowly to form a layer protection part of the three-dimensional object. The addition of the second liquid material in the non-molding area mainly prevents the first liquid material in the molding area from penetrating into the non-molding area, preventing the penetrating first liquid material from interacting with the powder material in the non-molding area to affect the surface precision of the molded object, and / or prevents the powder material in the non-molding area from melting and adhering to the surface of the molded object to affect the surface precision of the object, and the small molecule substance does not remain on the three-dimensional object obtained by printing, and the small molecule substance does not precipitate during use, which meets the requirements for safety and environmental protection.

[0176] FIG. 5 is a flowchart of a printing method for a three-dimensional object provided by another embodiment of the present application. Unlike the case of FIG. 2, this embodiment inkjet prints a first liquid material A and a second liquid material B in different scanning directions during printing, and ejects the second liquid material B first, followed by the first liquid material A.

[0177] Specifically, after step S11, the printing method includes the following steps: In step S202, in a first scanning direction, a second liquid material is first added in a molding area of ​​the powder material layer at a first ratio according to the layer printing data of the molding area, and a second liquid material is first added in a non-molding area of ​​the powder material layer at a second ratio according to the layer printing data of the non-molding area. Subsequently, step S40 is carried out to heat the powder material layer to which the second liquid material has been added. Next, execute step S302 to add a first liquid material in a first ratio in the molding area of ​​the powder material layer according to the layer printing data of the molding area, where the second liquid material promotes a polymerization reaction of the first liquid material to form a layer solid portion of the three-dimensional object, and add a first liquid material in a second ratio in the non-molded area of ​​the powder material layer according to the layer printing data of the non-molded area to form a layer protection portion of the three-dimensional object, where the first scanning direction and the second scanning direction are opposite to each other, the first ratio is greater than the second ratio, the amount of the second liquid material in a unit volume of the molding area is less than the amount of the second liquid material in a unit volume of at least the partial non-molded area, and the amount of the first liquid material in a unit volume of the molding area is greater than the amount of the first liquid material in a unit volume of at least the partial non-molded area.

[0178] In this particular embodiment, the first liquid material and the second liquid material are added in different scanning directions, and the second liquid material is added first, and the powder material layer to which the second liquid material has been added is heated, and then the first liquid material is added. In this form, before the first liquid material is ejected, at least a partial evaporable component of the second liquid material is evaporated, so that the amount of the second liquid material in the non-molded area becomes large, and the evaporated component takes away the temperature of the powder material in the non-molded area, so that the temperature of the powder material in the non-molded area decreases and the concentration of other components of the second liquid material increases, which can promote the rate of polymerization reaction of the first liquid material and improve the surface accuracy of the formed object.

[0179] In this application, the following examples and comparative examples are obtained by printing using the three-dimensional object printing method of FIG. 2 based on the three-dimensional printing material provided in the above description, and the printing steps of the examples and comparative examples are the same.

[0180] Example 1: Using polypropylene particles as the powder material, the liquid material is formulated as follows: [Table 1] Note: Water-soluble polyester resin does not react during molding process and has a Tg of 10℃.

[0181] Example 2: Using polyurethane particles as the powder material, the liquid material is prepared as follows. [Table 2] Note: The water-based acrylate emulsion Tg is -10°C.

[0182] Example 3: Using polyurethane particles as the powder material, the liquid material is prepared as follows. [Table 3] Note: Water-based polyurethane Tg is 0°C.

[0183] Example 4: Using polyurethane particles as the powder material, the liquid material is prepared as follows. [Table 4] Note: The water-based acrylate emulsion Tg is -10°C.

[0184] Example 5: Using polyamide particles as the powder material, the liquid material is prepared as follows. [Table 5] Note: The water-based acrylate emulsion Tg is -10°C.

[0185] Example 6: Using polyamide particles as the powder material, the liquid material is prepared as follows. [Table 6] Note: The water-based acrylate emulsion Tg is -10°C.

[0186] Example 7: Using polyamide particles as the powder material, the liquid material is prepared as follows. [Table 7] Note: The water-based acrylate emulsion Tg is -10°C.

[0187] Example 8: Using cellulose acetate as the powder material, the liquid material is prepared as follows: [Table 8] Note: The water-based acrylate emulsion Tg is 40°C.

[0188] Example 9: Using the three-dimensional printing material in Example 5 in combination with the printing method of the three-dimensional object in FIG. 2, the preheating temperature is 175° C., the heating temperature is 180° C., and a single voxel V voxel is printed using eight drops of ink, with the volume of each ink drop being essentially the same, the first ratio is 4:4, meaning that four ink drops of the first liquid material and four ink drops of the second liquid material are ejected into a single voxel in the molding area, and the second ratio is 0:8, meaning that no first liquid material is ejected into the non-molding area, and only eight ink drops of the second liquid material are ejected into a single voxel in the non-molding area.

[0189] Example 10: Using the three-dimensional printing material in Example 5 in combination with the printing method of the three-dimensional object in FIG. 2, the preheating temperature is 175° C., the heating temperature is 180° C., and a single voxel V voxel is printed using 8 drops of ink, with the volume of each ink drop being essentially the same, the first ratio may be 7:1, meaning that 7 drops of the first liquid material and 1 drop of the second liquid material are ejected into a single voxel in the molding area, and the second ratio may be 3:5, meaning that 3 drops of the first liquid material and 5 drops of the second liquid material are ejected into a single voxel in the non-molding area.

[0190] Example 11 Using the three-dimensional printing material in Example 5 in combination with the printing method of the three-dimensional object in FIG. 2, the preheating temperature is 175° C., the heating temperature is 180° C., and a single voxel V in the molding area is printed during inkjet printing. voxel is printed with 8 drops of ink, and a single voxel V in the non-molded area voxel is printed using four drops of ink, with the volumes of each ink drop being essentially the same, the first ratio may be 6:2, meaning that six ink drops of the first liquid material and two ink drops of the second liquid material are ejected into a single voxel in the molding area, and the second ratio may be 1:3, meaning that one ink drop of the first liquid material and three ink drops of the second liquid material are ejected into a single voxel in the non-molding area.

[0191] Comparative Example 1: Using polyurethane particles as the powder material, the liquid material is prepared as follows. [Table 9]

[0192] Comparative Example 2: The polyurethane particles are used as the powder material, and the first liquid material in Example 2 is used as the liquid material in the blending ratio.

[0193] Comparative Example 3: Using polyurethane particles as a powder material and the first liquid material in Example 4 as the blending ratio of the first liquid material to be the jet liquid, the second liquid material is prepared as follows. [Table 10] Note: The water-based acrylate emulsion Tg is -10°C.

[0194] Comparative Example 4: The polyamide particles are used as the powder material, and the first liquid material in Example 5 is used alone as the blending ratio of the jet liquid.

[0195] Comparative Example 5: Using polyamide particles as the powder material and the first liquid material in Example 5 as the blending ratio of the first liquid material to be the jet liquid, the second liquid material is prepared as follows. [Table 11] Note: The water-based acrylate emulsion Tg is -10°C.

[0196] Comparative Example 6: Using polyamide particles as a powder material and the first liquid material in Example 5 as a first liquid material to be ejected, a second liquid material is prepared as follows. [Table 12] Note: The Tg of water-based acrylate emulsion B is 90°C.

[0197] Comparative Example 7: Using polyamide particles as a powder material and the first liquid material in Example 5 as a first liquid material to be ejected, a second liquid material is prepared as follows. [Table 13]

[0198] Comparative Example 8: Using the three-dimensional printing material in Example 5 in combination with the printing method of the three-dimensional object in FIG. 2, the preheating temperature is 175° C., the heating temperature is 180° C., and a single voxel V voxel is printed using four drops of ink, the volumes of each ink drop are essentially the same, the first ratio is 1:1, meaning that two ink drops of the first liquid material and two ink drops of the second liquid material are ejected onto a single voxel in the molding area, and the second ratio is 1:1, meaning that two ink drops of the first liquid material and two ink drops of the second liquid material are ejected onto a single voxel in the non-molding area.

[0199] Comparative Example 9: Using the three-dimensional printing material in Example 5 in combination with the printing method of the three-dimensional object in FIG. 2, the preheating temperature is 175° C., the heating temperature is 180° C., and a single voxel V in the molding area is printed during inkjet printing. voxel is printed with 12 drops of ink, and a single voxel in the non-molded area V voxel is printed using 8 drops of ink, with the volume of each ink drop being basically the same, the first ratio is 11:1, meaning that 11 drops of the first liquid material and 1 drop of the second liquid material are ejected onto a single voxel in the display molding area, and the second ratio is 3:5, meaning that 3 drops of the first liquid material and 5 drops of the second liquid material are ejected onto a single voxel in the non-molding area.

[0200] Comparative Example 10 Using the three-dimensional printing material in Example 5 in combination with the three-dimensional object printing method of Figure 2, the preheating temperature is 175°C, the heating temperature is 180°C, and during inkjet printing, a single voxel Vvoxel in the molding area is printed using 8 drops of ink, and a single voxel Vvoxel in the non-molded area is printed using 4 drops of ink, the volume of each ink drop is basically the same, the first ratio is 4:4, which means that 4 drops of ink drops of the first liquid material and 4 drops of ink drops of the second liquid material are respectively ejected onto a single voxel in the molding area, and the second ratio is 1:3, which means that 1 drop of ink drops of the first liquid material and 3 drops of ink drops of the second liquid material are respectively ejected onto a single voxel in the non-molded area.

[0201] Performance Testing

[0202] 1.First liquid material performance test: The first liquid materials prepared in Examples 1 to 8 and the liquid material prepared in Comparative Example 1 were dried in an oven at room temperature of 25°C and 70°C, respectively, and the test results are shown in Table 1. [Table 14].

[0203] Table 1. Storage stability test of the first liquid material [Table 14]

[0204] From the test data in Table 1. [Table 14], it can be seen that the first liquid material provided by Example 1, Example 3 to Example 5 and Example 8 does not contain a high-temperature initiator, the first liquid material provided by Example 2, Example 6 and Example 7 contains a high-temperature initiator, and the first liquid material provided by Comparative Example 1 contains a low-temperature initiator. From the experimental test data, it can be seen that the first liquid material does not contain an initiator, the first liquid material has excellent storage stability, and if the first liquid material contains a low-temperature initiator, the storage stability of the first liquid material decreases, but even if the first liquid material contains a high-temperature initiator at a temperature that induces the low-temperature initiator to function, it does not affect the storage stability of the first liquid material. Unlike the case of Example 2, the high-temperature initiators in Examples 6 and 7 are all relatively stable at room temperature, and the storage stability of the first liquid material can be ensured.

[0205] 2. Performance testing of 3D objects Based on the powder material provided by Example 1, a sample was printed using the method for printing a three-dimensional object in FIG. 2 (ratio of the first liquid material to the second liquid material) at a preheat temperature of 150° C. The powder materials provided by Examples 2-4 and Comparative Examples 1-3 were printed using the method for printing a three-dimensional object in FIG. 2 at a preheat temperature of 110° C. The powder materials provided by Examples 5-7, Examples 9-11, and Comparative Examples 4-10 were used in combination with the method for printing a three-dimensional object in FIG. 2 at a preheat temperature of 175° C., and the powder material provided by Example 8 was used in combination with the method for printing a three-dimensional object in FIG. 2 at a preheat temperature of 150° C. In Examples 1 to 8, Comparative Example 3, Comparative Example 5, Comparative Example 6, and Comparative Example 7, the total volume of the ink amount in a single voxel in the molding region and the non-molding region is the same, and the volume of each ink drop is basically the same. In the example of ejecting eight ink drops of liquid material into a single voxel, the volume ratio of the first liquid material to the second liquid material in the molding region is 6:2, and the volume ratio of the first liquid material to the second liquid material in the non-molding region is 2:6. The samples were printed according to the printing method for three-dimensional objects. Comparative Example 1, Comparative Example 2, and Comparative Example 4 were printed according to the printing method for three-dimensional objects so that eight ink drops of liquid material were ejected into a single voxel in the molding region.

[0206] 2.1) Tensile strength test of samples: The samples were subjected to tensile strength testing according to GB / T 1040.2-2006 plastic tensile property determination standard.

[0207] 2.2) Sample breaking elongation test: The measurements were performed according to GB / T 1040.2-2006 plastic tensile property determination standard.

[0208] The test results of tensile strength and elongation at break of the samples are shown in Table 2.

[0209] Table 2. Test results of tensile strength and elongation at break of samples [Table 15]

[0210] 2.3) Testing the dimensional stability and roughness of the samples: The target length of the sample was 70.00 mm, the target width was 10.00 mm, and the target thickness was 3.00 mm. The width, thickness, and length of the sample actually obtained by printing were measured, and the difference between the actual measured values ​​and the target values ​​was calculated. △W width = actual measured width - target width △D thickness = actual measured thickness - target thickness △L length = actual measured length - target length

[0211] The roughness values ​​of the printed samples were measured using a surface roughness tester.

[0212] The dimensional stability and roughness test results of the samples are shown in Table 3.

[0213] Table 3. Dimensional stability and roughness test results of samples [Table 16]

[0214] The materials of Example 2 and Comparative Example 2 in Table 2 [Table 15] are formulated using the same first liquid material, and the liquid material provided by Comparative Example 2 does not contain the second liquid material containing the initiation accelerator. Test results show that the sample of Example 2 has significantly better tensile strength and breaking elongation than the sample of Comparative Example 2. This is because the high-temperature initiator of the first liquid material of Example 2 does not produce a good initiation polymerization action unless the second liquid material containing the initiation accelerator is introduced, and the second liquid material containing the initiation accelerator is not added to Comparative Example 2, so that the polymerization reaction does not occur effectively after the first liquid material and the powder material are mixed, and the mechanical properties of the sample are poor.

[0215] In Example 2, the first liquid material and the second liquid material are added to the powder material layer, and in Comparative Example 2, the second liquid material is not added. From Table 3. [Table 16], it can be seen that the values ​​of ΔW, ΔD, ΔL and roughness of Comparative Example 2 are larger, which shows that when the first liquid material is used in combination with the second liquid material, the improving effect on the dimensional stability and roughness of the three-dimensional object is obvious.

[0216] In Example 4 and Comparative Example 3, the same polyurethane powder and the same first liquid material are used, the weight percentage of the powder release agent in the second liquid material provided by Example 4 is 2%, and the weight percentage of the powder release agent in the second liquid material provided by Comparative Example 3 is 15% (more than 10%). From Table 3 [Table 16], it can be seen that the values ​​of ΔW, ΔD, ΔL and roughness of Comparative Example 3 are larger than those of Example 4, which indicates that when the powder release agent exceeds a certain content, the difference in the effect on the actual part and the protective part is not obvious, and the second liquid material does not produce a significant effect.

[0217] In Table 2 [Table 15], the same first liquid material is used in Example 5 and Comparative Example 4, and the second liquid material in Example 5 contains an initiator, but the second liquid material containing an initiator is not added in Comparative Example 4. Therefore, Example 5 is obviously superior in tensile strength and breaking elongation to Comparative Example 4. The values ​​of ΔW, ΔD, ΔL, and roughness of the printed sample in Comparative Example 4 are larger than those in Example 5, which indicates that the effects of the first liquid material and the second liquid material containing an initiator sprayed and added to the powder material layer on dimensional stability and roughness can be confirmed.

[0218] In Example 5 and Comparative Example 5, the same first liquid material is used, and the second liquid material provided by Comparative Example 5 does not contain a powder release agent. From Table 3. [Table 16], it can be seen that, compared with Comparative Example 4 and Comparative Example 5, Comparative Example 5 has a certain degree of improvement effect on dimensional stability and roughness, but there is still a certain gap compared with Example 5, which shows that adding an appropriate amount of powder release agent to the second liquid material has an improvement effect on the dimensional stability and roughness of the three-dimensional object.

[0219] In Example 5 and Comparative Example 6, the same first liquid material is used, and the glass transition temperature Tg point of the release agent (aqueous acrylate emulsion) in the second liquid material provided by Comparative Example 6 is 90 ° C, which is more than 40 ° C, while the glass transition temperature Tg point of the release agent (aqueous acrylate emulsion) in the second liquid material provided by Example 5 is -10 ° C, which is lower than 40 ° C. The ΔW and ΔD of the sample obtained by printing in Comparative Example 6 are positive values, but the roughness is much larger than that of Example 5. This shows that when a release agent with a high glass transition temperature wraps around powder material particles, it is likely to adhere to the surface of the sample, the error value is biased to a positive value, and the surface is rougher, so it is necessary to control the glass transition temperature of the release agent in the second liquid material to be lower than 40 ° C.

[0220] In Example 5 and Comparative Example 7, the same first liquid material is used, and the second liquid material provided by Comparative Example 7 does not contain a release agent, and the values ​​of ΔW, ΔD, ΔL, and roughness of the sample printed in Comparative Example 7 are close to those of the sample in Example 5, but there is still a certain gap with Example 5. This indicates that the inclusion of a release agent in the second liquid material has a certain degree of improving effect on the dimensional stability and roughness of the sample.

[0221] In Examples 5, 9, 10, 11, Comparative Example 8, Comparative Example 9, and Comparative Example 10, the same powder material and liquid material are used, but different printing methods are used.

[0222] In Comparative Example 8, the tensile strength and breaking elongation are much lower than those of Examples 5, 9, 10, and 11. This is probably due to the small amount of ink and the small amount of the first liquid material in Comparative Example 8. However, ΔW, ΔD, and ΔL in Comparative Example 8 are larger than the target values, and the protective part and the substantial part of the non-molded area are adhered as a molding layer during molding.

[0223] The tensile strength and breaking elongation of Comparative Example 9 are much lower than those of Examples 5, 9, 10, and 11. This is believed to be due to the fact that Comparative Example 9 contains too much first liquid material and too little second liquid material, resulting in insufficient second liquid material to promote the polymerization reaction of the first liquid material, and therefore insufficient polymerization of the first liquid material, and as a result, the tensile strength and breaking elongation are too low.

[0224] In comparison example 10, although the volume ratio of the first liquid to the second liquid in the molding area and the volume ratio of the first liquid to the second liquid in the non-molding area were within the range, the amount (volume) of the second liquid material per unit volume of the molding area was larger than the amount (volume) of the second liquid material per unit volume of the non-molding area, and combined with the large overall ink amount of the first liquid material, ΔW, ΔD, and ΔL were larger than the target values, resulting in large roughness.

[0225] In another aspect, FIG. 6 is a structural schematic diagram of a three-dimensional object printing apparatus provided by an embodiment of the present application. As shown in FIG. 6, an embodiment of the present application further provides a three-dimensional object printing apparatus for implementing the above-mentioned three-dimensional object printing method, the printing apparatus includes a powder supply member 2, a molding platform 3, a print head 26, and a controller 9; The powder supplying member 2 supplies a powder material to form a powder material layer L0 including a molded region and a non-molded region, The molding platform 3 supports the formed powder material layer L0, The print head 26 ejects a first liquid material A and a second liquid material B. The controller 9 controls the print head 26 to add the first liquid material A and the second liquid material B, which promotes the polymerization reaction of the first liquid material A, in a first ratio within the molding area of ​​the powder material layer according to the layer printing data, to form a layer substantial portion of the three-dimensional object; The controller 9 controls the print head 26 to add the first liquid material A and the second liquid material B in a second ratio in the non-molded area of ​​the powder material layer according to the layer printing data to form a layer protection portion of the three-dimensional object, wherein the first ratio is greater than the second ratio, and the amount of the second liquid material B in a unit volume of the molding area is less than the amount of the second liquid material B in a unit volume of at least the partial non-molded area, and the amount of the first liquid material A in a unit volume of the molding area is greater than the amount of the first liquid material A in a unit volume of at least the partial non-molded area.

[0226] In this embodiment, the powder supply member 2 includes a powder storage chamber 23, a lifting assembly 22, and a powder spreader 21, the powder storage chamber is for storing powder material 0, and has a movable support plate 231 inside the powder storage chamber 23, the lifting assembly 22 is connected to the support plate 231 and can move the support plate 231 up or down in the Z direction, and the powder spreader 21 is for spreading the powder material 0 in the powder storage chamber 23 onto the molding platform 3 to form a powder material layer L0, and the commonly used powder spreader 21 may be a powder spreading rod or a scraper.

[0227] The print head 26 has a first orifice array 26a and a second orifice array 26b, the first orifice array 26a being for ejecting a first liquid material A and the second orifice array 26b being for ejecting a second liquid material B, or the first orifice array 26a being for ejecting the first liquid material A and the second liquid material B mixed in a first ratio and the second orifice array 26b being for ejecting the first liquid material A and the second liquid material B mixed in a second ratio.

[0228] In the present application, the first liquid material A and the second liquid material B are two different liquid materials, which are stored separately in different material storage containers such as ink cartridges, and the first liquid material and the second liquid material are transported through different liquid material transport lines. The specific compositions of the first liquid material A and the second liquid material B can be referred to in detail in the above description of the three-dimensional printing material, and will not be described again here.

[0229] In one embodiment, the first liquid material A and the second liquid material B may be ejected in a ratio such that the first liquid material A and the second liquid material B are mixed in a ratio before being transported to and ejected from the respective orifice arrays of the print head 26, and then the mixed liquid materials are ejected onto the formed or non-formed areas of the powder material layer.

[0230] FIG. 7a is a schematic diagram of a local structure of a liquid supply device in a printing apparatus for a three-dimensional object provided by an embodiment of the present application. As shown in FIG. 7a, in one embodiment, a first liquid material A is stored in an ink cartridge 21a and transported to a mixing container 25a or 25b through an ink tube 23a via a pump 22a, and a second liquid material B is stored in an ink cartridge 21b and transported to a mixing container 25a or 25b through an ink tube 23b via a pump 22b, and the first liquid material B in the mixing container 25a is mixed with the first liquid material A. The first liquid material A and the second liquid material B are mixed in a first ratio, and the first liquid material A and the second liquid material B in mixing container 25b are mixed in a second ratio, and switches 24a and 24b are for controlling the supply of ink of the first liquid material A and the second liquid material B to mixing container 25a or the supply of ink of the first liquid material A and the second liquid material B to mixing container 25b.Specific switches 24a and 24b are not limited in type as long as they can control the supply of ink of the first liquid material A and the second liquid material B to a specified mixing container, and may be, for example, an electromagnetic valve.

[0231] FIG. 7b is a local structural schematic diagram of a liquid supply device in a three-dimensional object printing apparatus provided by an embodiment of the present application. As shown in FIG. 7b, in another embodiment, the first liquid material A is stored in the ink cartridge 21a, transported to the mixing container 25a via the ink tube 23a via the pump 22a, and transported to the mixing container 25b via the ink tube 23c via the pump 22c; the second liquid material B is stored in the ink cartridge 21b, transported to the mixing container 25a via the ink tube 23b via the pump 22b, and transported to the mixing container 25b via the ink tube 23d via the pump 22d; the first liquid material A and the second liquid material B in the mixing container 25a are mixed in a first ratio, and the first liquid material A and the second liquid material B in the mixing container 25b are mixed in a second ratio. By supplying ink to the first orifice array 26a from a mixture of a first liquid material A and a second liquid material B mixed in a first ratio, and supplying ink to the second orifice array 26b from a mixture of the first liquid material A and the second liquid material B mixed in a second ratio, inkjet printing of molded and non-molded areas of the powder material layer is realized to obtain layer solid portions and layer protected portions of a three-dimensional object.

[0232] In an embodiment of the present application, the first liquid material A and the second liquid material B may be ejected in a ratio by supplying ink from the first liquid material A and the second liquid material B to different orifice arrays of the print head 26 via different ink supply lines, such that the liquid materials are ejected in different ratios on the powder layer.

[0233] Fig. 7c is a schematic diagram of a local structure of a liquid supply device in a printing apparatus for a three-dimensional object provided by an embodiment of the present application, in another embodiment, as shown in Fig. 7c, a first liquid material A is stored in an ink cartridge 21a and transported to a first orifice array 26a of a print head via an ink tube 23a through a pump 22a. A second liquid material is stored in an ink cartridge 21b and transported to a second orifice array 26b of a print head via an ink tube 23b through a pump 22b.

[0234] The controller controls the first orifice array 26a and the second orifice array 26b of the print head 26 to eject the first liquid material A and the second liquid material B, respectively, in a first ratio in the molding area of ​​the powder material layer according to the layer printing data, and controls the first orifice array 26a and the second orifice array 26b to eject the first liquid material A and the second liquid material B, respectively, in a second ratio in the non-molding area of ​​the powder material layer according to the layer printing data, so that the first liquid material A and the second liquid material B are contacted in the powder material layer.

[0235] 8a is a schematic diagram of the surface structure of printhead orifices in a three-dimensional object printing apparatus provided by an embodiment of the present application, as shown in Fig. 8a, the first orifice array 26a and the second orifice array 26b can be an integrated multi-pass printhead, or can be two multi-pass printheads, and the multi-pass printhead 26 includes at least two rows of orifices, such as two rows, three rows, four rows, etc. In one specific embodiment, the printhead 26 has four rows of orifices, and the orifices in each row can be controlled independently.

[0236] FIG. 8b is a structural schematic diagram of the surface of another printhead orifice provided by an embodiment of the present application, and as shown in FIG. 8b, the first orifice array 26a and the second orifice array 26b can be a single-pass printhead, and the printhead 26 is a single-pass printhead.

[0237] 8c is a structural schematic diagram of the surface of another printhead orifice provided by an embodiment of the present application, and as shown in FIG. 8c, the first orifice array 26a and the second orifice array 26b can be an integrated single-pass printhead and a multi-pass printhead. In one specific embodiment, the printhead 26 is an integrated single-pass printhead and a multi-pass printhead, and each orifice is independently controllable, such as controlling whether each orifice inkjet or not and / or whether each orifice ejects ink droplets of variable sizes.

[0238] In the present application, the first liquid material and the second liquid material are stored separately in different ink cartridges and transported using different ink transport lines, thereby improving the storage stability of the liquid materials, preventing the polymerization reaction of the first liquid material, and ensuring the fluency of the ink supply of the liquid material, while at the same time preventing the print head nozzle holes from clogging and damaging the print head.

[0239] Optionally, the printing apparatus for three-dimensional objects further includes a pre-heating member 53, which is disposed above the molding platform 3, for supplying radiant energy or thermal energy to pre-heat the powder material layer L0, which helps the second liquid material in the molding region to promote the polymerization reaction of the first liquid material to form a polymer, and contributes to the evaporation of evaporable components in the second liquid material in the non-molding region to remove the temperature of the powder material in the non-molding region. The pre-heating member 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, and there is no restriction on what kind of pre-heating member is specifically selected.

[0240] Optionally, the printing apparatus for three-dimensional objects further includes a heating member 51 and a heating member 52 for heating the powder layer onto which the second liquid material has been sprayed after the print head sprays the second liquid material, and the heating member 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. The specific form of the heating member to be selected is related to the type of the first active component of the first liquid material, or the type of the first active component and the type of the second auxiliary. When the first active component of the first liquid material generates a photopolymerization reaction, the heating member supplies radiation energy such as ultraviolet radiation to induce the photopolymerization reaction of the first active component by the ultraviolet radiation; when the first active component of the first liquid material generates a thermal polymerization reaction, the heating member supplies thermal energy by an infrared lamp, a microwave, a heating wire, a heating sheet, a heating plate, and the like, to induce the thermal polymerization reaction of the first active component of the first liquid material by the thermal energy.

[0241] Optionally, the three-dimensional object printing apparatus further includes a lifting mechanism 4, which is connected to the molding platform 3 and drives the molding platform 3 to rise or fall along a vertical direction. During printing, each time one three-dimensional object slice layer including a layer substance portion and a layer protection portion is formed, the lifting mechanism 4 drives the molding platform 3 to move downward by a distance equivalent to the thickness of one powder layer.

[0242] In this embodiment, the preheating member 53 may be mounted above the molding platform 3 or at the top of the molding chamber, and the heating member 51, the print head 26, and the heating member 52 are sequentially mounted on the guide rail 11 and can move along the guide rail 11.

[0243] The printing apparatus for the three-dimensional object may further comprise a temperature monitor (not shown) for monitoring the temperature of the powder material layer.

[0244] Additionally, the controller 9 is further used to control the operation of at least one of the powder supplying member 2, the pre-heating member 53, the heating members 51 and 52, and the temperature monitor. For example, the temperature monitor feeds back the monitored temperature to the controller 9, and the controller controls the amount of energy provided by the pre-heating member 53 and / or the heating members 51 and 52 according to the information fed back from the temperature monitor.

[0245] An embodiment of the present application further provides a non-transitory computer-readable storage medium, as shown in FIG. 9, in which the storage medium 91 includes a stored program 911, and when the program is executed, an apparatus equipped with the storage medium 91 is controlled to perform the above-mentioned method for printing a three-dimensional object.

[0246] An embodiment of the present application further provides a computer device, and as shown in FIG. 10, the computer device of the embodiment includes a processor 101, a memory 102, and a computer program 103 stored in the memory 102 and executable on the processor 101. When the processor 101 executes the computer program 103, a printing method for a three-dimensional object in the embodiment is implemented, and the description will be omitted here to avoid repetition.

[0247] The computer device may be a computing device such as a desktop computer, a laptop, a handheld computer, and a cloud server. The computer device may include, but is not limited to, a processor, a memory. Those skilled in the art will appreciate that the computer device may include more or less components than those shown, or a combination of certain components, or different components, for example, the computer device may further include input / output devices, network access devices, buses, etc.

[0248] The so-called processor may be a Central Processing Unit (CPU) or other general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA) or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, etc. The general purpose processor may be a microprocessor, or the processor may be any conventional processor, etc.

[0249] The memory may be an internal storage unit of the computer device, such as a hard disk or memory of the computer device. The memory may be an external storage device of the computer device, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) card, a Flash Card, etc., that is installed in the computer device. Furthermore, the memory may include not only the internal storage unit of the computer device but also an external storage device. The memory is for storing computer programs and other programs and data required by the computer device. The memory may be used to temporarily store data that has been output or is to be output.

[0250] The above are merely preferred embodiments of the present application, and are not intended to limit the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application shall be included in the scope of protection of the present application.

[0251] This application claims priority to a Chinese patent application filed with the China Patent Office on March 11, 2022, bearing application number 202210235881.X and entitled "Method and apparatus for printing three-dimensional objects, and three-dimensional printing materials," the entire contents of which are incorporated herein by reference.

Claims

1. 1. A method for printing a three-dimensional object, comprising: forming a powder material layer using the powder material, the powder material layer including formed and non-formed regions; adding, in a first ratio according to layer print data, within a molding area of ​​the powder material layer, a first liquid material and a second liquid material that promotes a polymerization reaction of the first liquid material to form a layer substantial portion of a three-dimensional object; and adding a first liquid material and a second liquid material in a second ratio in a non-molded area of ​​the powder material layer according to layer printing data to form a layer protection portion of the three-dimensional object, wherein the first ratio is greater than the second ratio, such that the amount of the second liquid material in a unit volume of the molding area is less than the amount of the second liquid material in a unit volume of at least partial non-molded area, and the amount of the first liquid material in a unit volume of the molding area is greater than the amount of the first liquid material in a unit volume of at least partial non-molded area.

2. 2. The printing method of claim 1, wherein the first ratio is a volume ratio of the first liquid material to the second liquid material, the first ratio being (1-10):1; and / or the second ratio is a volume ratio of the first liquid material to the second liquid material, the second ratio being (0-0.95):

1.

3. 2. The printing method according to claim 1, wherein the layer substance portion and the layer protection portion are located on the same horizontal plane, and the layer substance portion and the layer protection portion are arranged adjacent to each other.

4. 2. The printing method of claim 1, wherein the amount of the second liquid material in a unit volume of the non-molding region gradually decreases along a direction away from the molding region of the non-molding region.

5. 2. The printing method of claim 1, wherein the width of the layer protection portion is equal to or greater than the minimum diameter of a droplet of the applied liquid material.

6. Before ejecting a first liquid material and a second liquid material in a shaping area of ​​the powder material layer in a first ratio according to the layer printing data, and before ejecting a first liquid material and a second liquid material in a non-shaping area of ​​the powder material layer in a second ratio according to the layer printing data, the method for printing the three-dimensional object includes: The printing method of claim 1 , further comprising a step of pre-heating the powder material layer.

7. The printing method according to claim 6, wherein the preheating temperature is set to be 5° C. to 100° C. lower than the melting point or melting temperature of the powder material.

8. After adding a first liquid material and a second liquid material in a second ratio in the non-molded areas of the powder material layer according to the layer printing data, the method of printing the three-dimensional object comprises: The printing method of claim 6 , further comprising the step of heating the powder material layer to which the second liquid material has been added.

9. 9. The printing method according to claim 8, wherein the heating temperature is higher than 70°C and lower than the melting point or melting temperature of the powder material by promoting evaporation of water in the second liquid material and / or promoting dissolution of the powder material by the first liquid material and promoting a polymerization reaction of the first liquid material.

10. 9. The printing method according to claim 8, wherein the energy for the preheating and the heating includes at least one of radiation energy and thermal energy.

11. 2. The printing method of claim 1, wherein the first liquid material includes a first active ingredient for at least partially dissolving the powder material, and the second liquid material includes a second auxiliary for promoting a polymerization reaction of the first liquid material, a powder release agent, a stripping agent, a hydrocarbon chain surfactant, and water.

12. 12. The printing method according to claim 11, wherein the second liquid material contains, by weight, 0.1% to 40% of a second assistant, 30% to 90% of water, 0.01% to 10% of a powder release agent, 1% to 30% of a release agent, and 0.1% to 10% of a hydrocarbon chain surfactant, assuming that the total weight of the second liquid material is 100%.

13. (1) The second assistant agent is at least one selected from an initiator, an initiation promoter, and a catalyst; (2) The powder release agent is at least one selected from the group consisting of a silicon-containing water-soluble release agent, a silicon-containing water-dispersible release agent, a fluorine-containing water-soluble release agent, and a fluorine-containing water-dispersible release agent. (3) The powder release agent is at least one selected from the group consisting of a silicone oil emulsion, a fluorine-containing nonionic surfactant, and a fluorine-containing anionic surfactant; (4) The release agent is selected from water-soluble polymers and / or water-dispersible polymers having a glass transition temperature of less than 40° C.; and (5) The printing method according to claim 11 or 12, characterized in that the release agent satisfies at least one of the following characteristics: the release agent is at least one selected from the group consisting of polyether resin, polyester resin, poly(methyl)acrylate resin, and polyurethane resin, each having a glass transition temperature lower than 40° C.

14. The printing method of claim 12, wherein the second liquid material further comprises 0.05% to 30% by weight of a co-solvent.

15. 15. The printing method according to claim 14, wherein the co-solvent is at least one selected from the group consisting of alcohols, alcohol ethers, amides, pyrrolidones, organic acids, and organic salts.

16. After forming the layer substance part and the layer protection part of the three-dimensional object, the printing method includes:

2. The printing method according to claim 1, further comprising repeating the formation of the powder material layer and the addition of the first liquid material and the second liquid material to superimpose the obtained sliced ​​layers, including the layer substance portion and the layer protection portion, layer by layer to form a three-dimensional object.

17. A non-transitory computer-readable storage medium, the non-transitory computer-readable storage medium including a program stored therein, the program being executed to control an apparatus having the non-transitory computer-readable storage medium mounted thereon to execute the method for printing a three-dimensional object according to any one of claims 1 to 16.

18. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, a method for printing a three-dimensional object according to any one of claims 1 to 16 is implemented.

19. A three-dimensional object, characterized in that the three-dimensional object is obtained by printing according to the method for printing a three-dimensional object according to any one of claims 1 to 16.

20. A three-dimensional printing material for use with a three-dimensional printing powder material, the three-dimensional printing material comprising a first liquid material and a second liquid material; the first liquid material includes a first active ingredient capable of at least partially dissolving the powder material; A three-dimensional printing material, characterized in that, when the total weight of the second liquid material is 100%, the second liquid material contains, by weight, 0.1% to 40% of a second auxiliary for promoting a polymerization reaction of the first liquid material, 30% to 90% of water, 0.01% to 10% of a powder release agent, 1% to 30% of a stripping agent, and 0.1% to 10% of a hydrocarbon chain surfactant.

21. 1. A three dimensional printing material, comprising: a powder material, a first liquid material, and a second liquid material; the powder material is used to form a powder material layer, the first liquid material includes a first active ingredient that at least partially dissolves the powder material; A three-dimensional printing material, characterized in that, when the total weight of the second liquid material is 100%, the second liquid material contains, by weight, 0.1% to 40% of a second auxiliary for promoting a polymerization reaction of the first liquid material, 30% to 90% of water, 0.01% to 10% of a powder release agent, 1% to 30% of a stripping agent, and 0.1% to 10% of a hydrocarbon chain surfactant.

22. 22. The three dimensional printing material of claim 21, wherein the powder material layer includes shaped regions and non-shaped regions, and within the shaped regions, the first liquid material and the second liquid material are applied in a first ratio, and within the non-shaped regions, the first liquid material and the second liquid material are applied in a second ratio, the first ratio being greater than the second ratio.

23. 23. The three dimensional printing material of claim 22, wherein the first ratio is a volume ratio of the first liquid material to the second liquid material, the first ratio being (1-10):1; and / or the second ratio is a volume ratio of the first liquid material to the second liquid material, the second ratio being (0-0.95):

1.

24. The three dimensional printing material of claim 22, characterized in that the amount of the second liquid material in a unit volume of the molding region is less than the amount of the second liquid material in a unit volume of at least a portion of the non-molding region, and the amount of the first liquid material in a unit volume of the molding region is greater than the amount of the first liquid material in a unit volume of at least a portion of the non-molding region.

25. 22. The three dimensional printing material of claim 21, wherein the powder material comprises at least one of polystyrene, polyvinyl chloride, polyacrylonitrile, acrylonitrile-styrene-acrylate copolymers, polyamides, polyesters, polyurethanes, poly(methyl)acrylates, polyvinyl fluorides, chlorinated polyolefins, block-containing and / or graft copolymers soluble in the first active component, hydroxyl-containing polyvinyl alcohols, cellulose, modified celluloses.

26. The three-dimensional printing material of claim 20 or 21, characterized in that the first active component has an active group capable of participating in a polymerization reaction, and the active group includes at least one of a carbon-carbon double bond, a hydroxyl, a carboxyl, a heterocyclic propane group, a carbonate ester-based group, an epoxy group, a liquid cyclic lactone structure, and a cyclic acetal structure.

27. the first liquid material includes a second active component having an active group capable of participating in a polymerization reaction and not dissolving the powder material; The three-dimensional printing material of claim 20 or 21, characterized in that the second active component includes at least one of isobornyl acrylate, isobornyl methacrylate, dodecyl acrylate, dodecyl methacrylate, cyclic trimethylolpropane formal acrylate, a carbon-carbon double bond-containing prepolymer, an epoxy group-containing prepolymer, a monomer that promotes ring-opening polymerization of an epoxy group, a prepolymer that promotes ring-opening polymerization of an epoxy group, a solid cyclic lactone, and a cyclic amide-based compound.

28. A three-dimensional printing material as described in claim 20 or 21, characterized in that the weight percentage of the first active component in the first liquid material is 10% to 95% when the total weight of the first liquid material is 100%.

29. The three-dimensional printing material of claim 27, characterized in that the weight percentage of the second active component in the first liquid material is 5% to 90%, when the total weight of the first liquid material is 100%.

30. When the total weight of the first liquid material is 100%, the first liquid material further contains, by weight ratio, 0.01% to 30% of a first auxiliary agent; 22. The three dimensional printing material of claim 20 or 21, wherein the first auxiliary agent comprises at least one of a high temperature initiator, a leveling agent, an antifoaming agent, a polymerization inhibitor, an antioxidant, a plasticizer, a dispersant, a pigment, and a dye.

31. (1) The second assistant agent is at least one selected from an initiator, an initiation promoter, and a catalyst; (2) The powder release agent is at least one selected from the group consisting of a silicon-containing water-soluble release agent, a silicon-containing water-dispersible release agent, a fluorine-containing water-soluble release agent, and a fluorine-containing water-dispersible release agent. (3) The powder release agent is at least one selected from the group consisting of a silicone oil emulsion, a fluorine-containing nonionic surfactant, and a fluorine-containing anionic surfactant; (4) The release agent is selected from water-soluble polymers and / or water-dispersible polymers having a glass transition temperature of less than 40° C.; and (5) The three-dimensional printing material described in claim 20 or 21, characterized in that the release agent satisfies at least one of the following characteristics: the release agent is at least one selected from polyether resin, polyester resin, poly(methyl)acrylate resin, and polyurethane resin, each having a glass transition temperature lower than 40°C.

32. The three-dimensional printing material of claim 20 or 21, characterized in that the second liquid material further contains, by weight, 0.05% to 30% of a co-solvent, when the total weight of the second liquid material is 100%.

33. The three-dimensional printing material of claim 32, characterized in that the co-solvent is at least one selected from an alcohol-based solvent, an alcohol ether-based solvent, an amide-based solvent, a pyrrolidone-based solvent, an organic acid-based solvent, and an organic salt-based solvent.

34. 22. The three-dimensional printing material of claim 20 or 21, characterized in that the hydrocarbon chain surfactant is one or more selected from fatty alcohol polyoxyethylene ethers, sodium alkyl sulfonates, sodium alkyl benzene sulfonates, sodium alkyl sulfates, sodium alkyl succinic acid sulfonates, sodium sulfamates, polyethers, and polyoxyethylene polyoxypropylene ether block copolymers.

35. 1. An apparatus for printing a three-dimensional object, comprising: a powder supply member, a build platform, a print head, and a controller; the powder supplying member supplies powder material to form a powder material layer including a molded region and a non-molded region; the build platform supports the formed layer of powder material; the controller controls the print head to add, in a first ratio according to layer printing data, a first liquid material and a second liquid material that promotes a polymerization reaction of the first liquid material to form a layer substantial portion of the three-dimensional object within a molding area of ​​the powder material layer; wherein the controller controls the print head to add a first liquid material and a second liquid material in a second ratio in a non-molded area of ​​the powder material layer according to layer printing data to form a layer protection portion of the three-dimensional object, the first ratio being greater than the second ratio, such that an amount of the second liquid material in a unit volume of the molding area is less than an amount of the second liquid material in a unit volume of at least partial non-molded area, and an amount of the first liquid material in a unit volume of the molding area is greater than an amount of the first liquid material in a unit volume of the at least partial non-molded area.

36. 36. The apparatus for printing a three-dimensional object of claim 35, wherein the print head includes a first array of orifices for ejecting a first liquid material and a second liquid material in a first ratio, and a second array of orifices for ejecting the first liquid material and the second liquid material in a second ratio.

37. 36. The apparatus for printing a three-dimensional object of claim 35, wherein the print head includes a first orifice array and a second orifice array used to eject the first liquid material and the second liquid material in a first ratio, respectively, in the molding area, and to eject the first liquid material and the second liquid material in a second ratio, respectively, in the non-molding area.

38. The three-dimensional object printing apparatus of claim 35, further comprising a lifting mechanism, wherein each time one three-dimensional object slice layer including a layer solid portion and a layer protection portion is formed, the lifting mechanism drives the molding platform to move downward a distance equivalent to the thickness of one powder layer.

39. 36. The apparatus for printing a three-dimensional object of claim 35, further comprising a pre-heating member disposed above the molding platform and configured to pre-heat the powder material layer.

40. 36. The apparatus for printing a three-dimensional object of claim 35, further comprising a heating member disposed above the molding platform and configured to heat the powder material layer onto which the second liquid material is jetted.

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