A PETG modified material with high interlayer bonding strength and high printing speed for 3D printing and its preparation method

Abstract

This invention discloses a high-speed, high-interlayer-bonding PETG modified material for 3D printing and its preparation method. Through the synergistic effect of melt stabilizer, flow promoter, and flow improver, the material's fluidity is enhanced while maintaining its melt strength, thus meeting the requirements of high-speed printing. Simultaneously, controlling the amount of flow promoter ensures that the printed parts maintain high interlayer bonding strength. The filament of this invention can achieve high-speed printing at conventional nozzle temperatures below 260°C, with a printing speed ≥350 mm / s. The printed model exhibits no stringing and possesses high interlayer bonding strength, with a Z-axis tensile strength greater than 35 MPa.

Description

Technical Field

[0001] This invention relates to the field of 3D printing materials technology, and in particular to a PETG modified material for 3D printing with high interlayer bonding strength and high printing speed, and its preparation method. Background Technology

[0002] PETG (polyethylene terephthalate-1,4-cyclohexanedimethyl ester) is an amorphous copolyester with excellent transparency, heat resistance and impact resistance, and is inexpensive, making it a promising candidate for 3D printing FDM molding.

[0003] However, pure PETG material has high viscosity, resulting in slow printing speeds. When printing at temperatures below 260°C, the printing speed is generally no higher than 200 mm / s. Further increasing the printing speed leads to filament breakage and printing failure (in current technology, printing speeds above 300 mm / s are considered high-speed, and above 400 mm / s are considered ultra-high-speed; the Z-axis tensile strength indicates the quality of interlayer bonding, with higher Z-axis tensile strength indicating better interlayer bonding; the Z-axis tensile strength of conventional high-speed PETG filament prints on the market is generally <30 MPa). To improve the printing speed of PETG material, one existing approach is to use PETG material with a high melt flow index to prepare the printing filament, utilizing the material's high fluidity to increase printing speed; another approach is to increase the printer nozzle temperature, such as ≥260°C during printing, to improve the fluidity of the material during melting and thus increase printing speed. Both of these approaches have significant limitations. Using high-flow-rate PETG resin or increasing the nozzle temperature of the printer to improve the flowability of PETG material not only has a limited effect on increasing printing speed, but also causes serious problems such as stringing and material sticking to the nozzle during printing, resulting in poor appearance quality of the printed parts. Therefore, these two approaches to improving the printing speed of PETG material are not feasible in practical applications.

[0004] A search of existing technologies revealed that patent CN118165481A provides a high-layer viscous PETG for high-speed 3D printing and its preparation method. This method improves the thermal conductivity of the PETG resin matrix by adding 5-15 parts of alloy powder and 5-10 parts of plasticizer, thereby increasing printing speed and interlayer bonding strength. However, because alloy powder has high density, high price, and is difficult to disperse evenly during processing, this method not only significantly increases the density and cost of the modified material and the processing difficulty during production, but also leads to a significant decrease in interlayer bonding strength compared to pure PETG material due to the large amount of alloy powder added. Furthermore, the method does not clearly specify the actual printing speed achievable by the resulting product. Additionally, the melt flow index of the modified material obtained by this method is above 30 g / 10 min, making it prone to stringing problems during printing.

[0005] Therefore, developing a PETG modified material that can achieve high-speed printing at temperatures below 260℃, has good overall printing performance, and possesses strong interlayer bonding for application in the 3D printing field has become an urgent market demand. Summary of the Invention

[0006] To achieve the above objectives, this invention provides a PETG modified material for 3D printing with high interlayer bonding strength and high printing speed, and its preparation method.

[0007] In a first aspect, the present invention provides a PETG modified material for 3D printing with high interlayer bonding strength and high printing speed, comprising the following components by weight: 70-97.8 parts of PETG resin Melt stabilizer 0.2-20 parts Flow promoter 2-10 parts Flow improver 0.1-2 parts 0.2-1.5 parts lubricant Antioxidant 0.1-1 part The PETG resin selected has a melt index (240℃, 2.16kg) of 5~20g / 10min.

[0008] When the melt index of PETG resin is too low, insufficient material extrusion is likely to occur during product printing, making high-speed printing impossible. When the melt index of PETG resin is too high, not only is stringing defect likely to occur during product printing, but excessively high melt index printing is also prone to filament breakage, making high-speed printing impossible.

[0009] The melt stabilizer is one or more of the following: polymers containing epoxy functional groups, polymers containing maleic anhydride functional groups, and methyl methacrylate-butadiene-styrene copolymer.

[0010] The melt stabilizer used in this solution can not only significantly improve the toughness of the modified material, making the PETG high-speed 3D printing filament more resilient and less prone to breakage and clogging of the printer nozzle during long-term printing; it can also prevent the degradation of the PETG modified material during production and processing, improve the melt strength of the modified material, and make the melt less prone to fracture during high-speed printing.

[0011] The flow promoter is one or more of calcium carbonate, talc, montmorillonite, barium sulfate, and calcium sulfate whiskers, with a preferred particle size of 325 mesh to 4000 mesh. The flow promoter is preferably surface modified (e.g., treated with a coupling agent (such as a silane coupling agent or a titanate coupling agent) or a stearic acid additive).

[0012] This solution uses a small amount of flow promoter to further improve the stability of melt flow of modified materials during high-speed printing, ensuring that the melt is not easily broken during high-speed printing.

[0013] The flow improver is one or more of the following: organic modified polysiloxane polymer, copolymerized polysiloxane polymer, and phosphate ester polymer.

[0014] The flow improver used in this solution can, on the one hand, appropriately improve the flowability of the modified material, supporting the high volumetric flow rate required for high-speed printing; on the other hand, it can reduce the friction between the melt and the inner wall of the nozzle during high-speed printing, making the melt flow out of the nozzle smoothly and less prone to breakage.

[0015] The lubricant is one or more of calcium stearate, pentaerythritol stearate (PETS), and ethylene bis-stearamide.

[0016] The antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, and antioxidant 168.

[0017] Secondly, the present invention provides the above-mentioned PETG modified material for 3D printing with high interlayer bonding strength and high printing speed, comprising the following steps: Step S1: Weigh the raw materials according to the component ratio of the PETG modified material for high interlayer bonding strength and high printing speed for 3D printing, add them to the high-speed mixer, and mix at high speed for 5 min to 10 min to obtain a mixture; Step S2: Add the mixture to the hopper of a twin-screw extruder, and melt, plasticize, mix, extrude, pelletize and dry the raw material through the twin-screw extruder at a temperature of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0018] The present invention adopts the above technical solution and has the following technical effects compared with the prior art: The filaments prepared using the modified material of this scheme can achieve high-speed printing when the conventional nozzle temperature is below 260℃, with a printing speed of ≥350mm / s. The printed model has no stringing and the printed parts have high interlayer bonding strength and Z-axis tensile strength greater than 35MPa.

[0019] Meanwhile, this solution utilizes the synergistic effect of melt stabilizer, flow promoter, and flow improver to enhance the fluidity of the modified material while ensuring its melt strength, thus enabling the modified material to meet the requirements of high-speed printing. At the same time, controlling the amount of flow promoter ensures that the printed parts of the modified material still maintain high interlayer bonding strength.

[0020] The PETG modified material with high interlayer bonding strength and high printing speed obtained by this invention has good application effects in the field of 3D printing. Detailed Implementation

[0021] The present invention will now be described in detail and specifically through specific embodiments to enable a better understanding of the invention. However, the following embodiments do not limit the scope of the invention. Example 1

[0022] This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 97.8 parts of PETG resin (melt index 12.8 g / 10 min, test conditions 240℃, 2.16 kg), 0.2 parts of epoxy functional group-containing melt stabilizer SOG-02 (produced by Jia Yi Rong Company), 2 parts of flow promoter calcium carbonate (particle size 325 mesh), 0.1 parts of organic modified polysiloxane polymer flow improver SILIMER9100 (produced by Chengdu Silike Company), 0.2 parts of lubricant calcium stearate, and 0.1 parts of antioxidant 1010 according to the component ratio of the PETG modified material for high interlayer bonding strength and high printing speed for 3D printing. Add them to a high-speed mixer and mix at 800 rpm at room temperature for 5 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0023] If the PETG resin raw material is damp before use, it needs to be dried in a 65~70℃ forced air or dehumidification drying oven until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 300rpm.

[0024] The 3D printing filament was prepared as follows for printing performance testing.

[0025] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm. Example 2

[0026] This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 70 parts of PETG resin (melt index 19.6 g / 10 min, test conditions 240℃, 2.16 kg), 0.4 parts of epoxy functional group-containing melt stabilizer HPC-3510P (produced by Jia Yi Rong Company), 19.6 parts of methyl methacrylate-butadiene-styrene copolymer, 10 parts of flow promoter talc powder (particle size 4000 mesh), 2 parts of organic modified polysiloxane polymer flow improver SILIMER9200 (produced by Chengdu Silike Company), 1.5 parts of lubricant PETS, 0.5 parts of antioxidant 1076, and 0.5 parts of antioxidant 168 into a high-speed mixer and mix at 1500 rpm at room temperature for 10 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0027] If the PETG resin raw material is damp before use, it must be dried in a 65~70℃ forced air or dehumidification drying oven until the moisture content of the raw material is ≤500ppm before use. The screw speed of the twin-screw extruder is 500rpm.

[0028] The 3D printing filament was prepared as follows for printing performance testing.

[0029] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm. Example 3

[0030] This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 80 parts of PETG resin (melt index 5.5 g / 10 min, test conditions 240℃, 2.16 kg), 0.3 parts of epoxy functional group-containing melt stabilizer BTCE-9013 (produced by Nanjing Baitong Company), 13.7 parts of maleic anhydride functional group-grafted ethylene-methyl acrylate copolymer melt stabilizer FB323 (produced by Jia Yirong Company), 6 parts of flow promoter montmorillonite (particle size 3000 mesh), 0.5 parts of organic modified polysiloxane polymer flow improver SILIMER9300 (produced by Chengdu Silike Company), 1 part of lubricant ethylene bis-stearamide, 0.3 parts of antioxidant 1098, and 0.3 parts of antioxidant 168 into a high-speed mixer and mix at 2000 rpm at room temperature for 8 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0031] If the PETG resin raw material is damp before use, it needs to be dried in a 65~70℃ forced air or dehumidification drying oven until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 400rpm.

[0032] The 3D printing filament was prepared as follows for printing performance testing.

[0033] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm. Example 4

[0034] This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 90 parts of PETG resin (melt index 16g / 10min, test conditions 240℃, 2.16kg), 0.5 parts of epoxy functional group melt stabilizer SMG-03 (produced by Jia Yi Rong Company), 5.5 parts of epoxy functional group melt stabilizer BT-308 (produced by Nanjing Baitong Company), 4 parts of flow promoter barium sulfate (particle size 2500 mesh), 1 part of copolymer polysiloxane polymer flow improver SILIMER5150 (produced by Chengdu Silike Company), 0.8 parts of lubricant ethylene bis-stearamide, 0.4 parts of antioxidant 1010, and 0.3 parts of antioxidant 168 into a high-speed mixer and mix at 1000rpm at room temperature for 8 minutes to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0035] If the PETG resin raw material is damp before use, it needs to be dried in a 65~70℃ forced air or dehumidification drying oven until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 300rpm.

[0036] The 3D printing filament was prepared as follows for printing performance testing.

[0037] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm. Example 5

[0038] This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 85 parts of PETG resin (melt index 9.3 g / 10 min, test conditions 240℃, 2.16 kg), 7 parts of maleic anhydride functional group grafted polyolefin elastomer melt stabilizer FB621 (produced by Jia Yi Rong Company), 8 parts of flow promoter calcium sulfate whiskers (particle size 2500 mesh), 1 part of phosphate ester polymer flow improver EMI150B (produced by Jia Yi Rong Company), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200 rpm at room temperature for 10 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0039] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0040] The 3D printing filament was prepared as follows for printing performance testing.

[0041] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0042] Comparative Example 1 This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 92 parts of PETG resin (melt index 9.3 g / 10 min, test conditions 240℃, 2.16 kg), 8 parts of flow promoter calcium sulfate whiskers (particle size 2500 mesh), 1 part of phosphate ester polymer flow improver EMI150B (produced by Jia Yi Rong Company), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200 rpm at room temperature for 10 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0043] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0044] The 3D printing filament was prepared as follows for printing performance testing.

[0045] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0046] Comparative Example 2 This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 93 parts of PETG resin (melt index 9.3 g / 10 min, test conditions 240℃, 2.16 kg), 7 parts of maleic anhydride functional group grafted polyolefin elastomer melt stabilizer FB621 (produced by Jia Yi Rong Company), 1 part of phosphate ester polymer flow improver EMI150B (produced by Jia Yi Rong Company), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200 rpm at room temperature for 10 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0047] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0048] The 3D printing filament was prepared as follows for printing performance testing.

[0049] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0050] Comparative Example 3 This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 85 parts of PETG resin (melt index 9.3 g / 10 min, test conditions 240℃, 2.16 kg), 7 parts of maleic anhydride functional group grafted polyolefin elastomer melt stabilizer FB621 (produced by Jia Yi Rong Company), 8 parts of flow promoter calcium sulfate whiskers (particle size 2500 mesh), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200 rpm at room temperature for 10 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0051] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0052] The 3D printing filament was prepared as follows for printing performance testing.

[0053] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0054] Comparative Example 4 This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 85 parts of PETG resin (melt index 30g / 10min, test conditions 240℃, 2.16kg), 7 parts of maleic anhydride functional group grafted polyolefin elastomer melt stabilizer FB621 (produced by Jia Yi Rong Company), 8 parts of flow promoter calcium sulfate whiskers (particle size 2500 mesh), 1 part of phosphate ester polymer flow improver EMI150B (produced by Jia Yi Rong Company), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200rpm at room temperature for 10min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0055] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0056] The 3D printing filament was prepared as follows for printing performance testing.

[0057] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0058] Comparative Example 5 This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 85 parts of PETG resin (melt index 3g / 10min, test conditions 240℃, 2.16kg), 7 parts of maleic anhydride functional group grafted polyolefin elastomer melt stabilizer FB621 (produced by Jia Yi Rong Company), 8 parts of flow promoter calcium sulfate whiskers (particle size 2500 mesh), 1 part of phosphate ester polymer flow improver EMI150B (produced by Jia Yi Rong Company), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200rpm at room temperature for 10min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0059] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0060] The 3D printing filament was prepared as follows for printing performance testing.

[0061] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0062] Comparative Example 6 This embodiment provides a PETG-modified material for 3D printing with high interlayer bonding strength and high printing speed. The preparation method specifically includes the following steps: Step S1: Weigh 78 parts of PETG resin (melt index 9.3 g / 10 min, test conditions 240℃, 2.16 kg), 7 parts of maleic anhydride functional group grafted polyolefin elastomer melt stabilizer FB621 (produced by Jia Yi Rong Company), 15 parts of flow promoter calcium sulfate whiskers (particle size 2500 mesh), 1 part of phosphate ester polymer flow improver EMI150B (produced by Jia Yi Rong Company), 0.6 parts of lubricant calcium stearate, 0.3 parts of antioxidant 1098, and 0.2 parts of antioxidant 168 into a high-speed mixer and mix at 1200 rpm at room temperature for 10 min to obtain a mixture. Step S2: Add the mixture to the hopper of a twin-screw extruder, and use the twin-screw extruder to melt, plasticize, mix, extrude, pelletize, and dry the raw material at a temperature range of 190℃~230℃ to obtain a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing.

[0063] If the PETG resin raw material is damp before use, it must be dried in a forced-air or dehumidification drying oven at 65~70℃ until the moisture content of the raw material is ≤500ppm before it can be used. The screw speed of the twin-screw extruder is 350rpm.

[0064] The 3D printing filament was prepared as follows for printing performance testing.

[0065] The obtained PETG modified material with high interlayer bonding strength and high printing speed for 3D printing was added to a 3D printing filament extruder and melted and plasticized at a temperature of 190℃~220℃ to form 3D printing filament for printing tests. The filament diameter was 1.75mm.

[0066] Performance testing standards: Interlayer bonding strength test: Place the wire on the printer and print a rectangular test strip with a height × width × thickness of 100mm × 20mm × 4mm along the Z-axis direction according to the model for Z-axis tensile strength test.

[0067] The printing process conditions for the interlayer bonding strength test strip were: nozzle temperature 255℃, sparse infill density 100%, and infill method was a straight line.

[0068] Printing speed test: Place the filament on the printer and print a grid model with a length × width × height of 150mm × 150mm × 5mm at different printing speeds. The highest printing speed corresponding to the grid model without defects such as missing material or broken filaments is the highest printing speed of the modified material.

[0069] The printing speed test printing process conditions were: nozzle temperature 255℃, sparse infill density 15%, and infill method as a grid.

[0070] Wire drawing performance test: Place the wire on the printer to print an antenna model and evaluate the wire drawing on the antenna. Printing process conditions: nozzle temperature 255℃.

[0071] The test results of the filament printing performance prepared by the modified materials in Examples 1-5 and Comparative Examples 1-6 are shown in Table 1: project Z-axis tensile strength (MPa) Printing speed mm / s Antenna model wire drawing situation Example 1 40.1 350 No stringing Example 2 33.7 400 No stringing Example 3 37.2 450 No stringing Example 4 38.6 450 No stringing Example 5 35.8 450 No stringing Comparative Example 1 36.6 200 Slight stringiness Comparative Example 2 40.2 200 No stringing Comparative Example 3 36 250 No stringing Comparative Example 4 34.3 200 Severe stringing Comparative Example 5 35.1 150 No stringing Comparative Example 6 24 350 No stringing As shown in Table 1, the wire-printed test pieces prepared using the modified material obtained by this method still maintain high Z-axis tensile strength and high interlayer bonding strength. Furthermore, the wire can achieve a printing speed of ≥350mm / s at the conventional PETG printing temperature of 255℃, meeting the requirements for high-speed printing, and the printed models show no stringing. However, without the synergistic effect of any of the melt stabilizers, flow promoters, or flow improvers, it is impossible to obtain a modified material that meets the requirements for high-speed printing. Additionally, using PETG resin with excessively high or low melt index as the modified material matrix also fails to obtain a modified material that meets the requirements for high-speed printing, and using PETG resin with excessively high melt index as the modified material matrix is ​​prone to stringing defects during printing.

[0072] The specific embodiments of the present invention have been described in detail above, but they are merely examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims

1. A PETG modified material for 3D printing with high interlayer bonding strength and high printing speed, comprising the following components by weight: 70-97.8 parts of PETG resin Melt stabilizer 0.2-20 parts Flow promoter 2-10 parts Flow improver 0.1-2 parts 0.2-1.5 parts lubricant Antioxidant 0.1-1 part The PETG resin selected has a melt index (240℃, 2.16kg) of 5~20g / 10min.

2. The PETG modified material according to claim 1, characterized in that: The melt stabilizer is one or more of the following: polymers containing epoxy functional groups, polymers containing maleic anhydride functional groups, and methyl methacrylate-butadiene-styrene copolymer.

3. The PETG modified material according to claim 1, characterized in that: The flow promoter is one or more of calcium carbonate, talc, montmorillonite, barium sulfate, and calcium sulfate whiskers.

4. The PETG modified material according to claim 1, characterized in that: The flow improver is one or more of the following: organic modified polysiloxane polymer, copolymerized polysiloxane polymer, and phosphate ester polymer.

5. The PETG modified material according to claim 1, characterized in that: The lubricant is one or more of calcium stearate, pentaerythritol stearate (PETS), and ethylene bis-stearamide; The antioxidant is one or more of antioxidant 1010, antioxidant 1076, antioxidant 1098, and antioxidant 168.

6. A method for preparing a PETG modified material with high interlayer bonding strength and high printing speed for 3D printing, comprising the following steps: Step S1: Weigh the raw materials according to the component ratio of the PETG modified material for high interlayer bonding strength and high printing speed for 3D printing as described in any one of claims 1-5, mix for 5 min to 10 min to obtain a mixture; Step S2: Melt, plasticize, mix, extrude, pelletize and dry the mixture at a temperature of 190℃~230℃.

7. The preparation method according to claim 6, characterized in that: The raw materials described in step S1 are mixed in a high-speed mixer; the mixture described in step S2 is processed in a twin-screw extruder.