Degradable 3D printing material as well as preparation method and application thereof

Abstract

The invention relates to the technical field of 3D printing, and particularly provides a degradable 3D printing material as well as a preparation method and application thereof, the tensile strength of the degradable 3D printing material is 20-33 MPa, and the tensile elongation at break is 6-31%. The degradable 3D printing material has moderate semi-crystallization time, the shrinkage rate and the warping rate of a printed piece are remarkably reduced, specifically, the shrinkage rate of the printed piece is not larger than 2.5%, the warping rate of the printed piece is not larger than 2%, the printed piece does not have a wiredrawing phenomenon in the printing process, meanwhile, the degradable 3D printing material has excellent tensile strength and tensile elongation at break, and the degradable 3D printing material has good application prospects. According to the degradable 3D printing material disclosed by the invention, the degradable 3D printing material has excellent mechanical properties, is easy to degrade in the environment, and particularly can be effectively degraded in a marine environment, so that the degradable 3D printing material has relatively high environmental protection value and relatively wide application prospects.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing, and in particular to a degradable 3D printing material and a preparation method and application thereof. Background Art

[0002] With the development of economy and social needs, the use of plastic products has become an indispensable item in people's lives, accompanied by the continuous reduction of non-renewable resources and serious environmental pollution. The seriousness of marine pollution has attracted great attention from human beings. The "white garbage" brought by non-degradable plastics has caused countless marine life to be on the verge of extinction and the marine ecosystem has been seriously damaged. In order to meet the world's environmental protection concept and solve the problem of energy required for industry development, biodegradable materials are constantly being used. They are easy to degrade and have little environmental pollution. They have covered the scope of medicine, biology and daily life.

[0003] At present, the research on marine degradable materials at home and abroad is still in its early stages, and only a few marine degradable materials have been born. Due to the differences in microbial groups and environments, general degradable materials do not show the same degradation speed and efficiency under seawater conditions as in composting environments, and some degradable materials do not even degrade in seawater environments. The more common 3D printing materials on the market now include PLA, PETG, ABS, PEEK, etc., but their degradation rates in the ocean are quite low, all below 3%. There are currently no mature marine degradable consumables, so it is particularly important to develop a material that is more in line with marine degradability.

[0004] PHA is a general term for high-molecular polyesters produced by fermentation of microorganisms using a variety of carbon sources. It is a large family of materials. Currently, there are four types of industrialized products: PHB, P34HB, PHBV, and PHBHHx. More than 150 different monomers have been discovered. By combining different monomer ratios, that is, by changing the culture conditions of microorganisms to adjust the monomer composition of PHA, many materials with different properties can be produced. In addition, PHA has good biodegradability and plasticity, and can be made into various products, such as plastic bags, tableware, containers, furniture, etc. At the same time, PHA also has excellent marine degradability, and its degradation efficiency and degradation rate are much higher than those of similar biodegradable materials.

[0005] 3D printing technology is a technology that uses a digital model file as the basis, and uses powdered metal or plastic and other bondable materials to construct objects by printing layer by layer. It is often used to make models in the fields of mold manufacturing, industrial design, etc., and is now gradually being used for the direct manufacturing of some products, especially some high-value applications (such as hip joints or teeth, or some aircraft parts). The most prominent advantage of 3D printing technology is that it can generate parts of any shape directly from computer graphics data without mechanical processing or any molds, thereby greatly shortening the product development cycle, improving productivity and reducing production costs, and has broad application prospects.

[0006] Therefore, combining PHA with 3D printing technology to prepare products can not only reduce costs, but most importantly, it is environmentally friendly. However, the 3D printing filaments currently prepared with PHA materials generally have obvious wire drawing during the printing process, serious shrinkage and warping, and the mechanical properties need to be improved. Summary of the invention

[0007] The present invention aims to solve one of the technical problems in the prior art at least to a certain extent. To this end, one object of the present invention is to provide a degradable 3D printing material and a preparation method and application thereof.

[0008] In a first aspect of the present invention, the present invention provides a degradable 3D printing material, wherein the tensile strength of the degradable 3D printing material is 20MPa~33MPa, and the tensile elongation at break is 6%~31%.

[0009] In some embodiments of the present invention, the half-crystallization time of the degradable 3D printing material is 5s-9s.

[0010] The above-mentioned degradable 3D printing material provided by the present invention has a moderate half-crystallization time, thereby significantly reducing the shrinkage and warpage of the printed part. Specifically, the shrinkage of the printed part is no more than 2.5%, the warpage is no more than 2%, and the printed part has no wire drawing phenomenon during the printing process. At the same time, the degradable 3D printing material has excellent tensile strength and tensile elongation at break, so that the printed part has excellent mechanical properties (strength and toughness).

[0011] In a second aspect of the present invention, the present invention proposes a degradable 3D printing material, wherein the raw materials for preparing the degradable 3D printing material include: a PHA material, a nucleating agent and a filling and reinforcing material, wherein the PHA material is selected from at least one of PHB, PHBV, PHBHHx and P34HB, and the filling and reinforcing material is selected from at least one of magnesium silicate, magnesium trisilicate, mica powder, calcium carbonate, chopped glass fiber, glass fiber powder, chopped carbon fiber and carbon fiber powder.

[0012] According to the above-mentioned degradable 3D printing material of the present invention, on the one hand, by selecting a specific type of PHA material, the 3D printing material not only has mechanical properties of both strength and toughness, but also has a moderate crystallization speed, which can meet the bottom fixation during printing, and is easy to remove after printing. At the same time, the moderate crystallization speed also ensures that the printed part has low shrinkage and low warping (the crystallization speed is too slow, the printed part is not easy to remove from the board, and the post-crystallization is serious, and the material will eventually warp; the crystallization speed is too fast, and the interlayer bonding force of the product is poor). On the other hand, by adding the above-mentioned inorganic filling reinforcement material as a reinforcement system, the above-mentioned inorganic filling reinforcement material is relatively low in price, which not only reduces the cost to a certain extent, but also improves the overall thermal conductivity of the formula, thereby contributing to the cooling and solidification of the PHA material, and is conducive to accelerating the winding speed and printing speed of the degradable 3D printing material when preparing the wire, and the above-mentioned inorganic filling reinforcement material can also reduce the wire drawing problem in the printing process. At the same time, through the mutual compounding and coordination of PHA material, nucleating agent and filling reinforcement material, the wire drawing phenomenon of 3D printing material during printing can be effectively avoided.

[0013] In some embodiments of the present invention, PHBV is selected from at least one of PHBV with a 3HV of 0.1-5 mol%, PHBV with a 3HV of 5-20 mol%, and PHBV with a 3HV of 25-40 mol%; PHBHHx is selected from at least one of PHBHHx with a 3HHx of 0.1-5 mol%, PHBHHx with a 3HHx of 5-15 mol%, and PHBHHx with a 3HHx of 20-40 mol%; P34HB is selected from at least one of P34HB with a 4HB of 0.1-7 mol%, P34HB with a 4HB of 7-20 mol%, and P34HB with a 4HB of 25-40 mol%.

[0014] Preferably, the raw materials for preparing the degradable 3D printing material include: PHA material, nucleating agent and filling reinforcing material, and the PHA material includes at least one of the first degradable material, the second degradable material, the third degradable material and the fourth degradable material; The first degradable material includes a first component, a second component and a third component, the second degradable material includes a first component and a second component, the third degradable material includes a first component and a third component, and the fourth degradable material includes a second component; The first component includes at least one of PHB, PHBV with a 3HV ratio of 0.1-5% by mole, PHBHHx with a 3HHx ratio of 0.1-5% by mole, and P34HB with a 4HB ratio of 0.1-7% by mole; the second component includes at least one of PHBV with a 3HV ratio of 5-20% by mole, PHBHHx with a 3HHx ratio of 5-15% by mole, and P34HB with a 4HB ratio of 7-20% by mole; the third component includes at least one of PHBV with a 3HV ratio of 25-40% by mole, PHBHHx with a 3HHx ratio of 20-40% by mole, and P34HB with a 4HB ratio of 25-40% by mole.

[0015] According to the above-mentioned degradable 3D printing material of the present invention, the raw materials for preparing the degradable 3D printing material include: 75-99 parts by weight of the PHA material, 0.1-3 parts by weight of the nucleating agent and 0.5-30 parts by weight of the filling and reinforcing material. By controlling the addition amount of the PHA material, the nucleating agent and the filling and reinforcing material within the above range, the mechanical properties of the degradable 3D printing material can be effectively improved, while reducing the shrinkage rate and warping rate of the printed part, and avoiding the generation of wire drawing during the printing process.

[0016] Preferably, the raw materials for preparing the degradable 3D printing material include: 80-90 parts by weight of the PHA material, 0.1-1 parts by weight of the nucleating agent and 2-11 parts by weight of the filling and reinforcing material.

[0017] According to the above-mentioned degradable 3D printing material of the present invention, the raw materials for preparing the degradable 3D printing material also include no more than 8 parts by weight of degradable materials, preferably 1 to 5 parts by weight, and the degradable materials are selected from at least one of PLA, PBS, PBAT, PBSA, PBST, PGA, and PCL, preferably PBSA.

[0018] In some embodiments of the present invention, the mesh number of the filling and reinforcing material is 100-2000 mesh, preferably 150 mesh to 1000 mesh, for example, the mesh number is 100 mesh, 300 mesh, 600 mesh, 1000 mesh, 1500 mesh, 2000 mesh, etc., or the range between any two of the above values. The filling and reinforcing material with the above mesh number can be well dispersed in the formulation system mainly composed of PHA materials, and in the subsequent granulation, wire drawing and 3D printing process, it will not be blocked due to too small mesh number and too large particle size, nor will it be unable to be evenly dispersed in the system due to too large mesh number and too small particle size, resulting in poor effect.

[0019] Preferably, the filling and reinforcing material includes at least one of chopped glass fiber, glass fiber powder, chopped carbon fiber, and carbon fiber powder. The above-mentioned fiber-type filling and reinforcing material has good compatibility with PHA materials and can better control the melt index, so that the degradable 3D printing material will not produce too much low-molecular-weight PHA during processing and application, thereby improving the thermal stability of PHA and ensuring the stability of the melt, thereby effectively avoiding the generation of drawing. Therefore, the use of the above-mentioned fiber-type filling and reinforcing material can ensure that there is no drawing during the printing process.

[0020] More preferably, the chopped glass fiber and chopped carbon fiber have an aspect ratio of not less than 40. The use of chopped glass fiber and chopped carbon fiber with an aspect ratio of not less than 40 not only avoids the generation of wire drawing during the printing process, but more importantly, the chopped glass fiber and chopped carbon fiber with an aspect ratio of not less than 40 can be used as the skeleton of the PHA base material, which can limit the final product size, thereby effectively reducing the shrinkage rate of the parts prepared by the degradable 3D printing material.

[0021] According to the above-mentioned degradable 3D printing material of the present invention, the nucleating agent includes at least one of a fatty acid amide nucleating agent, a fatty alcohol derivative nucleating agent, and a hexagonal crystal structure compound.

[0022] In some embodiments of the present invention, fatty acid amide nucleating agents include but are not limited to EBS, erucamide, oleamide, linoleamide, palmitic acid amide, etc., preferably oleamide and erucamide.

[0023] In some embodiments of the present invention, the fatty alcohol derivative nucleating agent includes but is not limited to xylitol, neopentyl glycol, trimethylolethane, pentaerythritol, isosorbide, sorbitol, mannitol, maltitol, erythritol, etc., preferably mannitol, trimethylolethane, isosorbide, pentaerythritol.

[0024] In some embodiments of the present invention, the hexagonal crystal structure compound includes but is not limited to boron nitride, silicon nitride, titanium nitride, boron carbide, silicon carbide, titanium carbide, magnesium oxide, aluminum oxide, etc., preferably boron carbide and boron nitride.

[0025] In some embodiments of the present invention, the nucleating agent also includes AD-506 or LD-6 (Jinan Chengju New Materials Co., Ltd.) and the like.

[0026] In a third aspect of the present invention, the present invention provides a method for preparing the above-mentioned degradable 3D printing material, the method comprising: The PHA material, nucleating agent and filling reinforcement material are mixed and then extruded.

[0027] The PHA material, the nucleating agent and the filling and reinforcing material are fully mixed and then extruded in an extruder to obtain a degradable 3D printing material. Thus, the method can be used to prepare a degradable 3D printing material with excellent mechanical properties, no wire drawing, low shrinkage rate of printed parts, and low warping rate.

[0028] In some embodiments of the present invention, the raw materials can be mixed evenly in a high-speed mixer. Preferably, the speed of the high-speed mixer is 100-1500 r / min, and the mixing time is 30 s-20 min. Further, after mixing, the raw materials are dried at 60-80 degrees Celsius for 0.5-12 hours.

[0029] In some embodiments of the present invention, the extrusion equipment includes a twin-screw extruder.

[0030] Preferably, the screw speed of the twin-screw extruder is 100-200r / min, for example, the speed is 100r / min, 120r / min, 150r / min, 180r / min, 200r / min, etc., or the range between any two of the above values. By controlling the screw speed of the twin-screw extruder within the above range, the material can be fully melted and plasticized, and the molecular weight of PHA is kept at a high level, and it will not be thermally degraded due to excessive shearing, nor will it be incompletely plasticized due to too weak shearing, thereby avoiding the problem of the extruded material strip having no strength, being fragile, and being easy to fall off powder, while ensuring a higher output.

[0031] In some embodiments of the present invention, the feeding rate of the twin-screw extruder is 5-160 kg / h, and the highest zone temperature is 110-180°C.

[0032] In a fourth aspect of the present invention, the present invention proposes a 3D printing wire, which is prepared by using the above-mentioned degradable 3D printing material or the degradable 3D printing material obtained by the above-mentioned method. Specifically, the degradable 3D printing material is prepared into a 3D printing wire by a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.). As a result, the 3D printing wire has excellent mechanical properties, the printed part has a lower shrinkage rate and warpage, and there is no wire drawing phenomenon during the printing process.

[0033] In some embodiments of the present invention, the highest zone temperature during the 3D printing wire preparation process is 120-190°C, the water temperature is 40-60°C, and the production winding speed is 40-80m / min.

[0034] In a fifth aspect of the present invention, the present invention proposes a 3D printing wire, the shear strength of the 3D printing wire is 20MPa-25MPa, and the printing speed of the 3D printing wire is 80mm / s-250mm / s. The 3D printing wire provided by the present invention has excellent shear strength, can improve the mechanical properties of the printed part, and the printing speed of the 3D printing wire is equal to or better than that of the traditional PLA wire, and has a higher printing speed than the marine degradable 3D printing wire products on the market, thereby significantly improving the production efficiency of the printed part.

[0035] In some embodiments of the present invention, the printing temperature using the above-mentioned 3D printing wire is 140-200°C.

[0036] In a sixth aspect of the present invention, a 3D printing wire is provided, wherein the shrinkage rate of a target part printed by the 3D printing wire is no more than 2.5%, the warping rate is no more than 1.9%, and there is no wire drawing during the printing process.

[0037] Specifically, the target piece is a sheet with a size of 20 cm (length)×20 cm (width)×3 mm (thickness).

[0038] Preferably, the shrinkage rate of the target part is 0.8%-2.5%, and the warpage rate is 0.5%-1.9%.

[0039] The present invention has at least the following technical effects: (1) The present invention selects a specific type of PHA material, so that the 3D printing material not only has mechanical properties of strength and toughness, but also has a moderate crystallization speed, which can meet the requirements of firm fixation of the bottom during printing and easy removal after printing. At the same time, the moderate crystallization speed also ensures low shrinkage and warpage of the printed parts. At the same time, the mutual compounding and synergy of PHA material, nucleating agent and filling and reinforcing material, especially the addition of specific filling and reinforcing material, can effectively avoid the phenomenon of wire drawing of 3D printing material during printing.

[0040] (2) The biodegradable 3D printing material of the present invention can achieve rapid wire preparation and rapid printing, which is comparable to the production winding speed (about 70m / min) and printing speed (100-200mm / s) of traditional PLA wires, thereby improving the industrial value of PHA-based wires. Compared with the marine-degradable products on the market from companies such as Color Fabb and Beyond Plastic (whose printing speed is only 40-80mm / s), the biodegradable 3D printing material of the present invention has a better application experience.

[0041] (3) The degradable 3D printing material of the present invention not only has excellent printing performance, but also can be degraded in the marine environment, effectively reducing environmental pressure and having great application value. DETAILED DESCRIPTION

[0042] Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. The present invention is described below with reference to specific embodiments. It should be noted that these embodiments are merely illustrative and do not limit the present invention in any way.

[0043] Example 1 The raw materials for preparing the degradable 3D printing material of this embodiment include: 75 parts by weight of PHA material: 50 parts by weight of PHB, 20 parts by weight of P34HB (the molar content of 4HB is 10%), and 5 parts by weight of P34HB (the molar content of 4HB is 33%); 1.5 parts by weight of nucleating agent: 0.5 parts by weight of erucamide, 1 part by weight of pentaerythritol; 10 parts by weight of filling and reinforcing materials: 5 parts by weight of calcium carbonate (1000 mesh), 5 parts by weight of carbon fiber powder (150 mesh).

[0044] The preparation process of the degradable 3D printing material of this embodiment is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 600 r / min for 5 min, and dry at 65 degrees Celsius for 2 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 65 machine as an example, the feeding speed is 60kg / h; the highest zone temperature is 145℃; the screw speed is 120r / min. After being extruded into strips, they are cooled and granulated to obtain the degradable 3D printing material.

[0045] The 3D printing wire preparation process of this embodiment is as follows: The degradable 3D printing material is prepared into degradable 3D printing filament through a 3D printing consumables production equipment line (extruder + drawing and winding mechanism, etc.), where the highest zone temperature is 175°C, the water temperature is 50°C, and the production winding speed is 65m / min.

[0046] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 190° C. and a printing speed of 100-200 mm / s.

[0047] Example 2 The raw materials for preparing the degradable 3D printing material of this embodiment include: 99 parts by weight of PHA material: 84 parts by weight of PHBV (the molar content of 3HV is 3%), 15 parts by weight of PHBHHx (the molar content of 3HHx is 20%); 3 parts by weight of nucleating agent: 0.5 parts by weight of EBS, 0.5 parts by weight of erucamide, 1 parts by weight of boron nitride, and 1 parts by weight of AD-506; 30 parts by weight of filling and reinforcing material: 20 parts by weight of glass fiber powder (200 mesh), 10 parts by weight of magnesium trisilicate (500 mesh).

[0048] The preparation process of the degradable 3D printing material of this embodiment is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 300 r / min for 15 min, and dry at 60 degrees Celsius for 4 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 35 machine as an example, the feeding speed is 8kg / h; the highest zone temperature is 140°C; the screw speed is 100r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0049] The 3D printing wire preparation process of this embodiment is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drawing and winding mechanism, etc.), wherein the highest zone temperature is 175°C, the water temperature is 50°C, and the production winding speed is 60m / min.

[0050] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 190° C. and a printing speed of 100-200 mm / s.

[0051] Example 3 The raw materials for preparing the degradable 3D printing material of this embodiment include: 80 parts by weight of PHA material: 80 parts by weight of PHBHHx (the molar content of 3HHx is 13%); Nucleating agent 0.5 parts by weight: 0.2 parts by weight of LD-6, 0.3 parts by weight of AD-506; 2 parts by weight of filling reinforcement material: 2 parts by weight of chopped carbon fiber (length ≤ 6 mm, aspect ratio > 120); The preparation process of the degradable 3D printing material of this embodiment is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 1000 r / min and a mixing time of 1 min. After mixing, dry at 75 degrees Celsius for 0.5 hours. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 35 machine as an example, the feeding speed is 12kg / h; the highest zone temperature is 110℃; the screw speed is 150r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0052] The 3D printing wire preparation process of this embodiment is as follows: The degradable 3D printing material is prepared into degradable 3D printing filament through a 3D printing consumables production equipment line (extruder + drawing and winding mechanism, etc.), where the highest zone temperature is 125°C, the water temperature is 40°C, and the production winding speed is 40m / min.

[0053] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 145° C. and a printing speed of 80-150 mm / s.

[0054] Example 4 The raw materials for preparing the degradable 3D printing material of this embodiment include: 90 parts by weight of PHA material: 70 parts by weight of PHBHHx (the molar content of 3HHx is 1%), 20 parts by weight of PHBV (the molar content of 3HV is 6%); 0.8 parts by weight of nucleating agent: 0.3 parts by weight of trimethylolethane, 0.5 parts by weight of isosorbide; 9 parts by weight of filling and reinforcing material: 7 parts by weight of mica powder (500 mesh), 2 parts by weight of carbon fiber powder (150 mesh).

[0055] The preparation process of the degradable 3D printing material of this embodiment is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 1500 r / min and a mixing time of 30 smin. After mixing, dry at 80 degrees Celsius for 0.5 hours. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 75 machine as an example, the feeding speed is 150kg / h; the highest zone temperature is 165℃; the screw speed is 180r / min. After being extruded into strips, they are cooled and granulated to obtain the degradable 3D printing material.

[0056] The 3D printing wire preparation process of this embodiment is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 185°C, the water temperature is 60°C, and the production winding speed is 80m / min.

[0057] The above-mentioned 3D printing wire is used to prepare printed products through a 3D printer, the printing temperature is 195° C., and the printing speed is 120-250 mm / s.

[0058] Example 5 The raw materials for preparing the degradable 3D printing material of this embodiment include: 85 parts by weight of PHA material: 60 parts by weight of P34HB (the molar content of 4HB is 1%), 25 parts by weight of PHBV (the molar content of 3HV is 30%); 0.8 parts by weight of nucleating agent: 0.5 parts by weight of oleic acid amide, 0.3 parts by weight of mannitol; 11 parts by weight of filling and reinforcing material: 4 parts by weight of magnesium silicate (800 mesh), 7 parts by weight of chopped glass fiber (length ≤ 5 mm, aspect ratio > 50).

[0059] The preparation process of the degradable 3D printing material of this embodiment is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 100 r / min for 20 min, and dry at 60 degrees Celsius for 12 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 18kg / h; the highest zone temperature is 130℃; the screw speed is 130r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0060] The 3D printing wire preparation process of this embodiment is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 165°C, the water temperature is 52°C, and the production winding speed is 65m / min.

[0061] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 180° C. and a printing speed of 100-200 mm / s.

[0062] Example 6 The raw materials for preparing the degradable 3D printing material of this embodiment include: 80 parts by weight of PHA material: 40 parts by weight of P34HB (the molar content of 4HB is 8%), 40 parts by weight of PHBHHx (the molar content of 3HHx is 6%); Degradable materials 5 parts by weight: 5 parts by weight of PBSA; Nucleating agent 0.1 parts by weight: 0.1 parts by weight of boron carbide; Filling reinforcement material 3 parts by weight: 3 parts by weight of glass fiber powder (200 mesh).

[0063] The preparation process of the degradable 3D printing material of this embodiment is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 750 r / min for 8 min, and dry at 70 degrees Celsius for 3 hours after mixing; S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 25kg / h; the highest zone temperature is 115℃; the screw speed is 160r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0064] The 3D printing wire preparation process of this embodiment is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 140°C, the water temperature is 45°C, and the production winding speed is 50m / min.

[0065] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 155° C. and a printing speed of 100-160 mm / s.

[0066] Comparative Example 1 The difference between the raw materials for preparing the degradable 3D printing material of this comparative example and the raw materials for preparing the material of Example 5 is as follows: 85 parts by weight of PHA material: 85 parts by weight of P34HB (the molar content of 4HB is 1%).

[0067] The preparation process of the degradable 3D printing material of this comparative example is the same as the preparation process of the degradable 3D printing material of Example 3.

[0068] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 165°C, the water temperature is 52°C, and the production winding speed is 65m / min.

[0069] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 180° C. and a printing speed of 100-200 mm / s.

[0070] Comparative Example 2 The difference between the raw materials for preparing the degradable 3D printing material of this comparative example and the raw materials for preparing the material of Example 5 is as follows: 85 parts by weight of PHA material: 60 parts by weight of P34HB (the molar content of 4HB is 10%), and 25 parts by weight of PHBV (the molar content of 3HV is 30%).

[0071] The preparation process of the degradable 3D printing material of this comparative example is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 100 r / min for 20 min, and dry at 60 degrees Celsius for 12 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 18kg / h; the highest zone temperature is 125℃; the screw speed is 130r / min. After being extruded into strips, they are cooled and granulated to obtain the degradable 3D printing material.

[0072] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing materials are prepared into degradable 3D printing wires through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 150°C, the water temperature is 45°C, and the production winding speed is 25m / min (the winding is not fast, otherwise the strips are too soft to solidify in time).

[0073] The above-mentioned 3D printing filament is used to prepare printed products through a 3D printer, the printing temperature is 160°C, and the printing speed is 30-60mm / s (printing is not fast, otherwise severe warping will occur).

[0074] Comparative Example 3 The difference between the raw materials for preparing the degradable 3D printing material of this comparative example and the raw materials for preparing the material of Example 5 is as follows: 85 parts by weight of PHA material: 85 parts by weight of PHBV (the molar content of 3HV is 25%).

[0075] The preparation process of the degradable 3D printing material of this comparative example is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 100 r / min for 20 min, and dry at 60 degrees Celsius for 12 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 18kg / h; the highest zone temperature is 75°C; the screw speed is 130r / min. After being extruded into strips, they are cooled and granulated to obtain the degradable 3D printing material.

[0076] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing materials are prepared into degradable 3D printing wires through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 100°C, the water temperature is 38°C, and the production winding speed is 5m / min (the winding is not fast, otherwise the strips are too soft to solidify in time).

[0077] The above-mentioned 3D printing filament is used to prepare printed products through a 3D printer, the printing temperature is 105°C, and the printing speed is 5-10mm / s (printing is not fast, otherwise severe warping will occur).

[0078] Comparative Example 4 The difference between the raw materials for preparing the degradable 3D printing material of this comparative example and the raw materials for preparing the material of Example 4 is as follows: Filling reinforcement material 11 parts by weight: 11 parts by weight of lignin fiber (length ≤ 3 mm, aspect ratio > 100).

[0079] The preparation process of the degradable 3D printing material of this comparative example is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 100 r / min for 20 min, and dry at 60 degrees Celsius for 12 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 18kg / h; the highest zone temperature is 130℃; the screw speed is 130r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0080] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 165°C, the water temperature is 52°C, and the production winding speed is 55m / min (the flow speed slows down, so the winding speed slows down).

[0081] The above-mentioned 3D printing filament is used to prepare printed products through a 3D printer, the printing temperature is 180°C, and the printing speed is 80-180mm / s (the flow speed slows down, so the printing speed slows down, but it is easy to get clogged).

[0082] Comparative Example 5 The difference between the raw materials for preparing the degradable 3D printing material of this comparative example and the raw materials for preparing the material of Example 5 is as follows: 41 parts by weight of filling and reinforcing material: 15 parts by weight of magnesium silicate (800 mesh), 26 parts by weight of chopped glass fibers (length ≤ 5 mm, aspect ratio > 50).

[0083] The preparation process of the degradable 3D printing material of this comparative example is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 100 r / min for 20 min, and dry at 60 degrees Celsius for 12 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 18kg / h; the highest zone temperature is 130℃; the screw speed is 130r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0084] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drafting and winding mechanism, etc.), wherein the highest zone temperature is 165°C, the water temperature is 52°C, and the production winding speed is 55m / min (the flow speed slows down, so the winding speed slows down).

[0085] The above-mentioned 3D printing filament is used to prepare printed products through a 3D printer, the printing temperature is 180°C, and the printing speed is 80-180mm / s (the flow speed slows down, so the printing speed slows down, but it is easy to get clogged).

[0086] Comparative Example 6 The difference between the raw materials for preparing the degradable 3D printing material of this comparative example and the raw materials for preparing the material of Example 5 is as follows: Comparative Example 6 does not add any filler reinforcement material.

[0087] The preparation process of the degradable 3D printing material of this comparative example is the same as the preparation process of the degradable 3D printing material of Example 3.

[0088] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing materials are prepared into degradable 3D printing wires through a 3D printing consumables production equipment line (extruder + drawing and winding mechanism, etc.), wherein the highest zone temperature is 160°C, the water temperature is 52°C, and the production winding speed is 50m / min (without filling, the cooling and solidification are slow, so the speed and temperature are forced to be reduced).

[0089] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 175° C. and a printing speed of 60-120 mm / s.

[0090] Comparative Example 7 The raw materials for preparing the degradable 3D printing material of this comparative example include: 85 parts by weight of PLA (right-hand ratio less than 2%); 0.8 parts by weight of nucleating agent: 0.5 parts by weight of oleic acid amide, 0.3 parts by weight of mannitol; 11 parts by weight of filling and reinforcing material: 4 parts by weight of magnesium silicate (800 mesh), 7 parts by weight of chopped glass fiber (length ≤ 5 mm, aspect ratio > 50).

[0091] The preparation process of the degradable 3D printing material of this comparative example is as follows: S1: Mix the above raw materials in a high-speed mixer at a speed of 100 r / min for 20 min, and dry at 60 degrees Celsius for 12 hours after mixing. S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 18kg / h; the highest zone temperature is 160℃; the screw speed is 130r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0092] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drawing and winding mechanism, etc.), wherein the highest zone temperature is 190°C, the water temperature is 52°C, and the production winding speed is 75m / min.

[0093] The above 3D printing wire is used to prepare printed products through a 3D printer, with a printing temperature of 210° C. and a printing speed of 100-200 mm / s.

[0094] Comparative Example 8 The raw materials for preparing the degradable 3D printing material of this comparative example are the same as the raw materials for preparing the degradable 3D printing material of Example 5.

[0095] The difference between the preparation process of the degradable 3D printing material of this comparative example and the preparation process of the degradable 3D printing material of Example 5 is as follows: S2: All the mixed raw materials are put into a twin-screw extruder for granulation. Taking the 45 machine as an example, the feeding speed is 30kg / h; the highest zone temperature is 130℃; the screw speed is 250r / min. After extrusion into strips, the strips are cooled and granulated to obtain the degradable 3D printing material.

[0096] The 3D printing wire preparation process of this comparative example is as follows: The above-mentioned degradable 3D printing material is prepared into degradable 3D printing wire through a 3D printing consumables production equipment line (extruder + drawing and winding mechanism, etc.), wherein the highest zone temperature is 160°C, the water temperature is 52°C, and the production winding speed is 55m / min (due to a certain degree of degradation in step S2, the temperature needs to be lowered during the preparation of the printing wire, and the curing becomes slower, so the winding speed is slowed down).

[0097] The above-mentioned 3D printing filament is used to prepare printed products through a 3D printer, with a printing temperature of 175°C and a printing speed of 80-120 mm / s, but it is still prone to drawing and warping.

[0098] In order to verify the performance of the degradable 3D printing material of the present invention, various performance parameters of the degradable 3D printing materials of the above-mentioned embodiments and comparative examples were measured, as follows: (1) Tensile strength and elongation at break: refer to GB / T 1040.2-2006.

[0099] (2) Load deformation temperature: refer to GB / T 1634.2 standard.

[0100] (3) Half crystallization time t 1 / 2 : DSC test combined with avrami formula calculation is used to judge the speed of crystallization.

[0101] (4) Evaluation of shrinkage and warping: Print the material into a 20cm×20cm×3mm sheet, observe the shrinkage and warping of the four corners and four sides, test the average side length, and the average value of the vertical height difference of the top of the four corners after warping, and calculate the shrinkage rate and warping rate respectively. That is: Shrinkage rate = side length difference / set side length × 100%; Warpage rate = height difference / set side length × 100%.

[0102] (5) Evaluation of the degree of drawing: Print the material into a standard test piece and observe the number of drawing lines. 0 lines means “no drawing”, 1-5 lines means “slight drawing”, 6-10 lines means “slight drawing”, 11-29 lines means “moderate drawing”, and 30 lines or more means “severe drawing”.

[0103] (6) Interlayer bonding strength: Referring to GB / T 30970-2014, the samples were prepared by 3D printing, and the printing plane direction was perpendicular to the sample direction at 90°, that is, the printing surface angle mentioned in the literature was 90° (DOI: 10.1016 / j.jmrt.2022.12.147), such as As shown, the shear strength is measured by this method to judge the interlayer bonding strength.

[0104] The measurement results of various performance parameters of the degradable 3D printing materials of the embodiments and comparative examples are shown in Table 1.

[0105] As can be seen from Table 1, the degradable 3D printing materials of Examples 3-6 not only have excellent mechanical properties, but also have low warpage and shrinkage of the printed parts. At the same time, there is no drawing during the printing process, and it has better production winding speed and printing speed. Comparative Examples 1-3 changed the composition of the PHA material. Although there was no drawing during the printing process, the warpage and shrinkage of Comparative Examples 2 and 3 increased significantly, and the interlayer bonding force of Comparative Example 1 was poor. Comparative Example 4 uses other types of cellulose (wood fiber), with high warpage and shrinkage, and serious drawing phenomenon. It may be that organic filling and reinforcing materials such as lignin, bamboo fiber, and jute fiber will undergo a certain degree of carbonization during processing, and this carbonization is discontinuous and extremely entropy-increasing, resulting in poor uniformity of the entire system, poor compatibility of polymers and filling and reinforcing materials, and no good skeleton-defect perfect composite material structure is formed. It is also impossible to promote the uniform, dense, and small-sized crystallization behavior of PHA at the microscopic level, which ultimately leads to the instability of the size of the 3D printed products at the macroscopic level, warping, and the melt will also produce drawing due to unstable flow rate. In Comparative Example 5, too much filling and reinforcing material is added, in Comparative Example 6, no filling and reinforcing material is added, in Comparative Example 7, the PHA material of the present invention is not used, and in Comparative Example 8, the screw speed is too high, and all of them have a certain degree of wiredrawing.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A degradable 3D printing material, characterized in that: The tensile strength of the degradable 3D printing material is 20MPa-33MPa, and the tensile elongation at break is 6%-31%.

2. The degradable 3D printing material according to claim 1, characterized in that: The half-crystallization time of the degradable 3D printing material is 5s-9s.

3. A degradable 3D printing material, characterized in that: The preparation raw materials include: PHA material, nucleating agent and filling reinforcement material, the PHA material is selected from at least one of PHB, PHBV, PHBHHx and P34HB, and the filling reinforcement material is selected from at least one of magnesium silicate, magnesium trisilicate, mica powder, calcium carbonate, chopped glass fiber, glass fiber powder, chopped carbon fiber and carbon fiber powder.

4. The degradable 3D printing material according to claim 3, characterized in that: PHBV is selected from at least one of PHBV with a 3HV of 0.1-5 mol %, PHBV with a 3HV of 5-20 mol %, and PHBV with a 3HV of 25-40 mol %; PHBHHx is selected from at least one of PHBHHx in which 3HHx is 0.1-5% by mole, PHBHHx in which 3HHx is 5-15% by mole, and PHBHHx in which 3HHx is 20-40% by mole; P34HB is selected from at least one of P34HB in which 4HB accounts for 0.1-7 mol %, P34HB in which 4HB accounts for 7-20 mol %, and P34HB in which 4HB accounts for 25-40 mol %.

5. The degradable 3D printing material according to claim 3 or 4, characterized in that: The PHA material is selected from at least one of a first degradation material, a second degradation material, a third degradation material and a fourth degradation material; The first degradable material includes a first component, a second component and a third component, the second degradable material includes a first component and a second component, the third degradable material includes a first component and a third component, and the fourth degradable material includes a second component; The first component includes at least one of PHB, PHBV with a 3HV ratio of 0.1-5 mol%, PHBHHx with a 3HHx ratio of 0.1-5 mol%, and P34HB with a 4HB ratio of 0.1-7 mol%. The second component comprises at least one of PHBV with a 3HV ratio of 5-20 mol%, PHBHHx with a 3HHx ratio of 5-15 mol%, and P34HB with a 4HB ratio of 7-20 mol%. The third component includes at least one of PHBV with a 3HV ratio of 25-40 mol%, PHBHHx with a 3HHx ratio of 20-40 mol%, and P34HB with a 4HB ratio of 25-40 mol%.

6. The degradable 3D printing material according to any one of claims 3 to 5, characterized in that: The raw materials for preparation include: 75-99 parts by weight of the PHA material, 0.1-3 parts by weight of the nucleating agent and 0.5-30 parts by weight of the filling and reinforcing material.

7. The degradable 3D printing material according to claim 6, characterized in that: The preparation raw materials also include no more than 8 parts by weight of a degradable material, and the degradable material is selected from at least one of PLA, PBS, PBAT, PBSA, PBST, PGA, and PCL.

8. The degradable 3D printing material according to any one of claims 3 to 7, characterized in that: The mesh size of the filling and reinforcing material is 100-2000 mesh; Preferably, the filling reinforcement material is selected from at least one of chopped glass fiber, glass fiber powder, chopped carbon fiber, and carbon fiber powder. More preferably, the aspect ratio of the fiber-based filling reinforcement material is not less than 40.

9. The degradable 3D printing material according to any one of claims 3 to 8, characterized in that: The nucleating agent includes at least one of a fatty acid amide nucleating agent, a fatty alcohol derivative nucleating agent, and a hexagonal crystal structure compound.

10. A method for preparing the degradable 3D printing material according to any one of claims 1 to 9, characterized in that: include: The PHA material, nucleating agent and filling reinforcement material are mixed and then extruded.

11. The method according to claim 10, characterized in that: The equipment used for extrusion includes twin-screw extruder; Preferably, the screw speed of the twin-screw extruder is 100-200 r / min; and / or, The feeding rate is 5-160kg / h, and the highest zone temperature is 110-180℃.

12. A 3D printing wire, characterized in that: The degradable 3D printing material is prepared by using the degradable 3D printing material according to any one of claims 1 to 9 or the degradable 3D printing material obtained by the method according to claim 10 or 11.

13. A 3D printing wire, characterized in that: The shear strength of the 3D printing wire is 20MPa-25MPa, and the printing speed of the 3D printing wire is 80mm / s-250mm / s.

14. A 3D printing wire, characterized in that: The shrinkage rate of the target part printed by the 3D printing wire is no more than 2.5%, and the warping rate is no more than 1.9%.

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