Binder for binder jet 3D printing and preparation method thereof

Abstract

The present invention discloses a binder comprising, based on 100 parts by mass of the binder, 15-50 parts by mass of polyethylene glycol, 5-15 parts by mass of ethylene acrylic acid, 0-10 parts by mass of diethylene glycol or hexylene glycol, and 100 parts by mass of ethanol. The binder of the present invention has high versatility and can be used for powder bed binder jetting additive manufacturing printing of most metals and some ceramics. It has a low degreasing temperature and leaves no residue, and is applicable to materials ranging from low-melting-point metals to high-sintering-temperature ceramics.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and in particular to a binder for binder jetting 3D printing and a preparation method thereof. Background Art

[0002] Binder Jetting (BJ) 3D printing technology is an additive manufacturing technology based on a powder bed (PB) that selectively sprays a binder according to a Computer Aided Design (CAD) model to form the powder. Compared with traditional forming technologies, it is an additive manufacturing technology that meets the design, optimization and manufacturing of complex structural parts; compared with other powder bed additive manufacturing technologies, it has higher production efficiency and lower costs. Binders play a vital role in this technology and have a significant impact on the process parameters of printing and subsequent sintering, and even the final performance of the parts. Finding a binder that meets the requirements of efficient binder jet printing, has a complete structure, sufficient strength and good surface quality of the green body after curing, has a fast degreasing speed, low temperature and no residue, and has no effect on the performance of the sintered parts, is an urgent problem to be solved. Summary of the Invention

[0003] In order to solve the above technical problems, the present invention provides a binder suitable for binder jet printing of metal and ceramic powders, and a preparation method and application thereof.

[0004] The present invention adopts the following technical solutions:

[0005] A binder comprises the following components in parts by mass based on 100 parts by mass of the binder: 15 to 50 parts of a main binder, 5 to 15 parts of a reinforcing agent, and 100 parts of a solvent. The main binder is polyethylene glycol, and the reinforcing agent is ethylene acrylic acid.

[0006] In the above formula, the main binder primarily binds the powder into shape, while the reinforcing agent improves toughness and rigidity. The solvent dissolves the main binder, reinforcing agent, and surfactant, and the surface tension and viscosity of the binder can be adjusted by adjusting the solvent.

[0007] Preferably, the binder further includes 0 to 5 parts of a surfactant, wherein the surfactant is polyvinyl pyrrolidone (PVP) or ethylene glycol butyl ether surfactant, which plays a role in improving the wetting effect and adjusting the viscosity. The amount of surfactant can be appropriately adjusted according to the thickness of the printed layer. The thicker the layer, the greater the amount used to ensure the penetration and wetting effect.

[0008] Preferably, the solvent is ethanol, a combination of ethanol and diethylene glycol, or a combination of ethanol and hexylene glycol. Ethanol, diethylene glycol, and hexylene glycol are selected as solvents because they are volatile and have strong permeability.

[0009] Preferably, the amount of the diethylene glycol or the hexylene glycol is 0 to 10 parts, and the ethanol is supplemented to 100 parts.

[0010] Preferably, the viscosity of the adhesive at a temperature of 40±3° C. is 12±5 cps, and the surface tension of the adhesive is 40±15 mN / m. Within this viscosity and surface tension range, the adhesive can better meet the parameter requirements of the nozzle jet printing.

[0011] Preferably, the average molecular weight of the polyethylene glycol is 200 to 8500 g / mol, more preferably the average molecular weight of the polyethylene glycol is 4000 to 8000 g / mol. If the molecular weight is too large, it will increase the difficulty of viscosity adjustment and degreasing efficiency; the AA (Acrylic Acid) content of the ethylene acrylic acid is 8 to 30%, and the MI (Melting Index) is 10 to 1000. Within this range, it has good strength and toughness; the weight average molecular weight / number average molecular weight of the polyvinyl pyrrolidone is 44000 to 54000 g / mol, the viscosity is suitable and does not affect the subsequent degreasing efficiency. Preferably, a binder, based on 100 parts by mass of the binder, includes the following components in parts by mass: 20 to 40 parts of polyethylene glycol, 8 to 12 parts of ethylene acrylic acid, 2 to 5 parts of polyvinyl pyrrolidone, 0 to 8 parts of diethylene glycol or hexylene glycol, and 100 parts of ethanol. The binder performance under this formula is better.

[0012] The present invention also provides a method for preparing a binder, comprising the following steps:

[0013] The main binder, reinforcing agent, surfactant, and solvent are weighed as described above; the solvent is ethanol, a combination of ethanol and diethylene glycol, or ethanol and hexylene glycol;

[0014] Add the enhancer to ethanol and heat and stir at 25-35°C with a magnetic stirrer for 60-200 minutes to dissolve;

[0015] Add the main binder and heat with a magnetic stirrer at 25-35°C for 30-90 minutes to dissolve;

[0016] Add surfactant, stir thoroughly with a magnetic stirrer, and let stand until bubbles in the solution are eliminated.

[0017] Furthermore, after adding the surfactant and stirring the solution thoroughly with a magnetic stirrer, the solution is allowed to stand until bubbles in the solution are eliminated, and diethylene glycol or hexylene glycol is added and stirred thoroughly with a magnetic stirrer.

[0018] The present invention also provides the use of the binder in forming metal powder or ceramic powder in a binder jet 3D printing process.

[0019] Compared with the prior art, the present invention has the following advantages:

[0020] 1. The binder of the present invention uses polyethylene glycol as the main binder, supplemented by ethylene acrylic acid for reinforcement and toughening, and polyvinyl pyrrolidone to promote infiltration and penetration, to meet the requirements of green parts, and can basically print green parts with complete structure, sufficient strength and good precision;

[0021] 2. The binder of the present invention is green and economical, the raw materials are easily available and cheap, and the harm to the environment is small. The main product after degreasing is small molecular gas, which will not remain in the parts and will not affect the final composition and performance of the parts after sintering.

[0022] 3. The binder of the present invention has strong versatility and can be used for printing most metals and some ceramic powder bed binder jetting additive manufacturing technology. It has a low degreasing temperature and no residue, and can be applied to everything from low melting point metals to high sintering temperature ceramics.

[0023] 4. The adhesive of the present invention is flexible and adaptable to various materials, structures and stress conditions. The adhesive composition can be adjusted according to the actual printing conditions (according to the material, structure and size of the manufactured parts, etc.) to meet the requirements of the green parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a green sheet diagram of Example 3;

[0025] Figure 2 yes Figure 1 The green body shown is after degreasing and sintering.

[0026] Figure 3 is a green sheet diagram of Example 4;

[0027] Figure 4 This is a green sheet diagram of Example 6.

[0028] In order to facilitate understanding of the technical solution of the present invention, a detailed description is given below with reference to the accompanying drawings and specific embodiments.

[0029] Example 1

[0030] Binder preparation: 15 parts polyethylene glycol (average molecular weight 2000 g / mol), 5 parts ethylene acrylic acid (AA: 12, MI: 20), 2 parts polyvinyl pyrrolidone (average molecular weight 48000 g / mol), 70 parts ethanol, and 8 parts 1,2-hexanediol were weighed. Ethylene acrylic acid was first added to ethanol and stirred with a magnetic stirrer at 30°C for 120 minutes to obtain solution S1. Polyethylene glycol was then added to solution S1 and stirred with a magnetic stirrer at 30°C for 60 minutes to obtain solution S2. Polyvinyl pyrrolidone was added to solution S2 and stirred thoroughly with a magnetic stirrer for 30 minutes to obtain solution S3. Hexanediol was then added to solution S3 and stirred thoroughly with a magnetic stirrer for 30 minutes. The solution was then allowed to stand for 2 hours to eliminate bubbles, resulting in the final binder. The binder had a viscosity of 10 cps and a surface tension of 40 mN / m at 40°C, meeting the technical requirements for the printhead.

[0031] The above binder is used in binder jet printing, and the specific steps are as follows:

[0032] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0033] 2. If the jetting test is normal, set the parameters of binder saturation to 90%, print layer thickness to 0.08mm, and curing time to 25s;

[0034] 3. After the above preparations are ready, the steps of powder laying (the powder here refers to stainless steel 316L powder, with a particle size of 15-53μm and a normal distribution), binder spraying and curing are carried out in sequence, and the cycle continues until the printing is completed;

[0035] 4. After printing is completed, the powder is cleaned to obtain a green body. The green body compressive strength is measured to be 0.4 MPa. It is stored in a dry environment to avoid moisture. After degreasing at 600℃ for 2h and sintering at 1360℃ for 3h, the final density of the sample is measured to be 7.69g / cm 3 , the density is 96.37%.

[0036] Example 2

[0037] Preparation of the binder: 22 parts polyethylene glycol (average molecular weight 4000 g / mol), 10 parts ethylene acrylic acid (AA: 20, MI: 300), 4 parts polyvinyl pyrrolidone (average molecular weight 48000 g / mol), 60 parts ethanol, and 4 parts diethylene glycol were weighed. The ethylene acrylic acid was first added to the ethanol and heated and stirred at 30°C for 120 minutes using a magnetic stirrer to obtain solution S1. The polyethylene glycol was then added to solution S1 and heated and stirred at 30°C for 60 minutes using a magnetic stirrer to obtain solution S2. The polyvinyl pyrrolidone was then added to solution S2 and stirred thoroughly with a magnetic stirrer for 30 minutes to obtain solution S3. Diethylene glycol was then added to solution S3 and stirred thoroughly with a magnetic stirrer for 30 minutes. The solution was allowed to stand for 1 hour to eliminate bubbles, resulting in the final binder. The binder had a viscosity of 12 cps and a surface tension of 40 mN / m at 40°C, meeting the technical requirements for the printhead.

[0038] The above binder is used in binder jet printing, and the specific steps are as follows:

[0039] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0040] 2. If the jetting test is normal, set the binder saturation to 85%, the printing layer thickness to 0.10mm, and the curing time to 25s;

[0041] 3. After the above preparations are ready, the steps of spreading powder (the powder here refers to 420 stainless steel powder, with a particle size of -25μm (referring to a particle size less than 25μm), and the particle size is normally distributed), spraying binder and curing are carried out in sequence, and the cycle continues until the printing is completed;

[0042] 4. After printing is completed, the powder is cleaned to obtain a green body. The green body compressive strength is measured to be 1.5 MPa. It is stored in a dry environment to avoid moisture. After degreasing at 600℃ for 2h and sintering at 1350℃ for 3h, the final density of the sample is measured to be 7.55g / cm 3 , the density reaches 97.42%.

[0043] Example 3

[0044] Binder preparation: 30 parts polyethylene glycol (average molecular weight 4000 g / mol), 8 parts ethylene acrylic acid (AA: 20, MI: 300), 5 parts polyvinyl pyrrolidone (average molecular weight 48000 g / mol), 54 parts ethanol, and 3 parts diethylene glycol were weighed. Ethylene acrylic acid was first added to the ethanol and heated and stirred at 30°C for 120 minutes using a magnetic stirrer to obtain solution S1. Polyethylene glycol was then added to solution S1 and heated and stirred at 30°C for 60 minutes using a magnetic stirrer to obtain solution S2. Polyvinyl pyrrolidone was then added to solution S2 and stirred thoroughly with a magnetic stirrer for 30 minutes to obtain solution S3. Diethylene glycol was then added to solution S3 and stirred thoroughly with a magnetic stirrer for 30 minutes. The solution was allowed to stand for 2 hours to eliminate bubbles, resulting in the final binder. The binder had a viscosity of 12 cps and a surface tension of 42 mN / m at 40°C, meeting the technical requirements for the printhead.

[0045] The above binder is used in binder jet printing, and the specific steps are as follows:

[0046] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0047] 2. If the jetting test is normal, set the binder saturation to 80%, the print layer thickness to 0.15mm, and the curing time to 20s;

[0048] 3. After the above preparations are ready, the steps of spreading powder (the powder here refers to 420 stainless steel powder, particle size -25μm), spraying binder and curing are carried out in sequence, and the cycle continues until the printing is completed;

[0049] 4. After printing is completed, the powder is cleaned to obtain the green body. Figure 1 As shown in Figure 2, the green body compressive strength is measured to be 2.0 MPa. It is stored in a dry environment to avoid moisture, degreased at 600 ° C for 1 h, and sintered at 1350 ° C for 3 h. Figure 2 As shown, the final measured sample density is 7.48 / cm 3 , the density reaches 96.52%.

[0050] Example 4

[0051] Binder preparation: 36 parts polyethylene glycol (average molecular weight 6000 g / mol), 10 parts ethylene acrylic acid (AA: 20, MI: 300), 4 parts polyvinyl pyrrolidone (average molecular weight 48000 g / mol), 48 parts ethanol, and 2 parts diethylene glycol were weighed. Ethylene acrylic acid was first added to the ethanol and heated and stirred at 30°C for 120 minutes using a magnetic stirrer to obtain solution S1. Polyethylene glycol was then added to solution S1 and heated and stirred at 30°C for 60 minutes using a magnetic stirrer to obtain solution S2. Polyvinyl pyrrolidone was then added to solution S2 and stirred thoroughly with a magnetic stirrer for 30 minutes to obtain solution S3. Diethylene glycol was then added to solution S3 and stirred thoroughly with a magnetic stirrer for 30 minutes. The solution was allowed to stand for 2 hours to eliminate bubbles, resulting in the final binder. The binder had a viscosity of 11 cps and a surface tension of 41 mN / m at 40°C, meeting the technical requirements for the printhead.

[0052] The above binder is used in binder jet printing, and the specific steps are as follows:

[0053] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0054] 2. If the jetting test is normal, set the binder saturation to 80%, the printing layer thickness to 0.12mm, and the curing time to 20s;

[0055] 3. After the above preparations are ready, the steps of spreading powder (stainless steel 316L powder, particle size 15-53μm, normal particle size distribution), spraying binder and curing are carried out in sequence, and the cycle continues until the printing is completed;

[0056] 4. After printing is completed, clean the powder to obtain the green body. Figure 3 As shown in the figure, the green body compressive strength was measured to be 2.2 MPa. The sample was stored in a dry environment to avoid moisture, degreased at 600 °C for 2 h, and sintered at 1360 °C for 3 h. The final density of the sample was 7.72 g / cm 3 , the density reaches 96.74%.

[0057] Example 5

[0058] Binder preparation: Weigh 50 parts polyethylene glycol (average molecular weight 6000 g / mol), 15 parts ethylene acrylic acid (AA: 20, MI: 300), 2 parts polyvinyl pyrrolidone (average molecular weight 48000 g / mol), and 33 parts ethanol. First, add the ethylene acrylic acid to the ethanol and heat and stir at 30°C with a magnetic stirrer for 120 minutes to obtain solution S1. Then, add the polyethylene glycol to solution S1 and heat and stir at 30°C with a magnetic stirrer for 60 minutes to obtain solution S2. Then, add the polyvinyl pyrrolidone to solution S2 and stir thoroughly with a magnetic stirrer for 30 minutes to obtain solution S3. The solution was allowed to stand for 2 hours to eliminate bubbles, resulting in the final prepared binder. The binder had a viscosity of 12 cps and a surface tension of 42 mN / m at 40°C, meeting the technical parameter requirements for the printhead.

[0059] The above binder is used in binder jet printing, and the specific steps are as follows:

[0060] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0061] 2. If the jetting test is normal, set the binder saturation to 90%, the print layer thickness to 0.10mm, and the curing time to 18s;

[0062] 3. After the above preparations are ready, the steps of spreading powder (stainless steel 420SS powder, particle size -25μm, normal particle size distribution), spraying binder and curing are carried out in sequence, and the cycle continues until the printing is completed;

[0063] 4. After printing is completed, the powder is cleaned to obtain a green body. The green body compressive strength is measured to be 2.8 MPa. It is stored in a dry environment to avoid moisture. After degreasing at 600℃ for 2h and sintering at 1350℃ for 3h, the final density of the sample is measured to be 7.49g / cm 3 , the density reaches 96.65%.

[0064] Example 6

[0065] Binder preparation: Weigh 22 parts of polyethylene glycol (average molecular weight 4000 g / mol), 9 parts of ethylene acrylic acid (AA: 12, MI: 20), 60 parts of ethanol, and 22 parts of 1,2-hexanediol. First, add the ethylene acrylic acid to the ethanol and heat and stir at 30°C with a magnetic stirrer for 120 minutes to obtain solution S1. Then, add the polyethylene glycol to solution S1 and heat and stir at 30°C with a magnetic stirrer for 60 minutes to obtain solution S2. Then, add 1,2-hexanediol to solution S2 and stir thoroughly with a magnetic stirrer for 30 minutes. The mixture was allowed to stand for 2 hours to obtain the final binder. The binder had a viscosity of 11 cps and a surface tension of 41 mN / m at 40°C, meeting the technical parameter requirements for the printhead.

[0066] The above binder is used in binder jet printing, and the specific steps are as follows:

[0067] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0068] 2. If the jetting test is normal, set the binder saturation to 88%, the print layer thickness to 0.06mm, and the curing time to 25s;

[0069] 3. After the above preparations are ready, the steps of spreading powder (stainless steel 420SS powder, particle size -25μm, normal particle size distribution), spraying binder and curing are carried out in sequence, and the cycle continues until the printing is completed;

[0070] 4. After printing is completed, clean the powder to obtain the green body. Figure 4 As shown in the figure, the green body compressive strength was measured to be 1.1 MPa. The sample was stored in a dry environment to avoid moisture, degreased at 600 °C for 2 h, and sintered at 1350 °C for 3 h. The final density of the sample was 7.45 g / cm 3 , the density reaches 96.13%.

[0071] Example 7

[0072] Binder preparation: 35 parts polyethylene glycol (average molecular weight 6000 g / mol), 11 parts ethylene acrylic acid (AA: 20, MI: 300), 3 parts polyvinyl pyrrolidone (average molecular weight 48000 g / mol), 48 parts ethanol, and 3 parts diethylene glycol were weighed. Ethylene acrylic acid was first added to the ethanol and heated and stirred at 30°C for 120 minutes using a magnetic stirrer to obtain solution S1. Polyethylene glycol was then added to solution S1 and heated and stirred at 30°C for 60 minutes using a magnetic stirrer to obtain solution S2. Polyvinyl pyrrolidone was then added to solution S2 and stirred thoroughly with a magnetic stirrer for 30 minutes to obtain solution S3. Diethylene glycol was then added to solution S3 and stirred thoroughly with a magnetic stirrer for 30 minutes. The solution was allowed to stand for 2 hours to eliminate bubbles, resulting in the final binder. The binder had a viscosity of 12 cps and a surface tension of 40 mN / m at 40°C, meeting the technical requirements for the printhead.

[0073] The above binder is used in binder jet printing, and the specific steps are as follows:

[0074] 1. Clean the ink cartridge and ink path, add adhesive to the ink cartridge, pump the adhesive into the ink path, exhaust the air, adjust the negative pressure to -1.5kPa, and perform a jet test. Printing can only be carried out after the jetting is normal.

[0075] 2. If the jetting test is normal, set the binder saturation to 80%, the printing layer thickness to 0.13mm, and the curing time to 25s;

[0076] 3. After the above preparations are ready, the steps of spreading powder (ZrO2 powder, particle size 500 mesh, normal particle size distribution), spraying binder and curing are carried out in sequence, and the cycle is repeated until the printing is completed;

[0077] 4. After printing is completed, the powder is cleaned to obtain a green body. The compressive strength of the green body is measured to be 2.3Mpa. After degreasing at 600℃ for 2h and sintering at 1650℃ for 3h, the final density of the sample is measured to be 5.61g / cm3, and the density reaches 92.42%.

[0078] Currently, the binder commonly used in binder jet printing of metals is phenolic resin. The printed green body has high strength. According to relevant reports, the compressive strength of the green body can reach 10MPa. However, its degreasing temperature is high, about 1050℃, and a large amount of carbon is easily left after degreasing, which not only affects the composition of the metal but also the density of the part (it is difficult to exceed 95%).

[0079] The binder of the present invention has a degreasing temperature of approximately 600°C, and the degreasing product is discharged as a small molecule gas with almost no residue, which can meet the printing requirements of most metal, alloy, and ceramic powders. Different ratios of binder components are selected based on the physical properties of the powder material used for printing, the part structure, and the stress conditions, so as to meet the requirements for obtaining qualified green parts. For example, the dosage of the main binder and reinforcing agent can be appropriately reduced for aluminum alloy parts with low density, simple structure, and low stress requirements. On the other hand, the dosage of the main binder and reinforcing agent can be appropriately increased for stainless steel parts with high density, complex structure, and high load-bearing capacity. The green strength obtained by printing within this formula range is within the range of 0.1-2.8MPa, which can meet the requirements of most situations. For example, the density of stainless steel powder after printing and sintering can reach over 95%. While achieving better part performance, the binder of the present invention has a low degreasing temperature and short degreasing time, which reduces energy consumption, improves efficiency and economic benefits, and has greater commercial application value.

[0080] The above are only preferred embodiments of the present invention. The scope of protection of the present invention shall be based on the scope defined by the claims. Several improvements and modifications made by those skilled in the art without departing from the spirit and scope of the present invention should also be regarded as the scope of protection of the present invention.

Claims

1. A binder, characterized in that: The invention relates to a binder comprising 100 parts by mass of the following components: 15 to 50 parts of a main binder, 5 to 15 parts of a reinforcing agent, and 100 parts of a solvent. The main binder is polyethylene glycol, and the average molecular weight of the polyethylene glycol is 200 to 8500 g / mol. The reinforcing agent is ethylene acrylic acid. The acrylic acid content of the ethylene acrylic acid is 8 to 30%, and the melt index is 10 to 1000. The binder further comprises 0 to 5 parts of a surfactant, and the surfactant is polyvinyl pyrrolidone or ethylene glycol butyl ether. The solvent is ethanol, a combination of ethanol and diethylene glycol, or ethanol and 1,2-hexanediol. The amount of the diethylene glycol or the 1,2-hexanediol is 0 to 10 parts, and the ethanol is sufficient to make up 100 parts.

2. The adhesive according to claim 1, wherein: The viscosity of the adhesive at a temperature of 40±3° C. is 12±5 cps, and the surface tension of the adhesive is 40±15 mN / m.

3. The adhesive according to claim 1, wherein: The average molecular weight of the polyvinyl pyrrolidone is 44,000 to 54,000 g / mol.

4. An adhesive according to claim 1, characterized in that: The binder comprises 100 parts by mass of the following components: 20-40 parts by mass of polyethylene glycol, 8-12 parts by mass of ethylene acrylic acid, 2-5 parts by mass of polyvinyl pyrrolidone, 0-8 parts by mass of diethylene glycol or 1,2-hexanediol, and 100 parts by mass of ethanol.

5. A method for preparing the adhesive according to any one of claims 1 to 4, characterized in that The following steps are involved: Weigh the main binder, reinforcing agent, surfactant, and solvent according to any one of claims 1 to 4; the solvent is ethanol, a combination of ethanol and diethylene glycol, or ethanol and 1,2-hexanediol; Add the enhancer to ethanol and heat and stir at 25-35°C with a magnetic stirrer for 60-200 minutes to dissolve; Add the main binder and heat with a magnetic stirrer at 25-35°C for 30-90 minutes to dissolve; Add surfactant, stir thoroughly with a magnetic stirrer, and let stand until bubbles in the solution are eliminated.

6. The method for preparing the adhesive according to claim 5, wherein: After adding the surfactant and stirring the solution thoroughly with a magnetic stirrer, the solution is allowed to stand until bubbles in the solution are eliminated, and diethylene glycol or 1,2-hexanediol is added and stirred thoroughly with a magnetic stirrer.

7. Use of the binder according to any one of claims 1 to 4 in the molding of metal powder or ceramic powder in a binder jet 3D printing process.

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