3D printing material based on three-phase system, 3D printing wire rod and 3D printing method

Abstract

The invention provides a 3D printing material based on a three-phase system. The 3D printing material comprises a first crystalline polymer, a second crystalline polymer and a third phase polymer, the second crystalline polymer comprises a micro-nano-scale fiber structure, and the melting point of the second crystalline polymer is higher than that of the first crystalline polymer; the third-phase polymer comprises at least one of a crystalline polymer and an amorphous polymer; the melting point of the crystalline polymer is lower than that of the second crystalline polymer; the glass transition temperature of the amorphous polymer is lower than the melting point of the second crystalline polymer. The presence of a third-phase polymer in the present specification can increase the content of a fiber structure having a high aspect ratio. Based on the advantages of high specific surface area, high crystallinity and high heat resistance of the fiber structures, a printed piece obtained by applying the 3D printing material through 3D printing can have both high heat resistance and high warping resistance.

Description

Technical Field

[0001] The present invention relates to the field of 3D printing technology, and more specifically, to a 3D printing material and a 3D printing wire based on a three-phase system, as well as a 3D printing method. Background Art

[0002] Material-Extrusion Based 3D printing (ME-3DP) is one of the most mainstream forms of polymer material additive manufacturing technology. Its principle is to melt the polymer material at high temperature to obtain melt fluidity, and then stack it layer by layer in a certain quantitative manner. In extrusion 3D printing technology, fused filament fabrication (FFF) is one of the mainstream technical forms.

[0003] In FFF printing, some materials have poor heat resistance due to their low crystallinity, which limits their application scenarios. For example, polylactic acid (PLA) material is currently the most common printing material in FFF printing. Its excellent anti-warping properties, interlayer adhesion, and full bio-based biodegradability make it the "best and most market-recognized" type of material. However, with the expansion of FFF printing applications, the low heat resistance of PLA material prints (heat softening temperature of about 60°C) has become one of its long-standing pain points. Specifically, the glass transition temperature T of PLA material is about 60°C. g About 60℃, melting temperature T m The temperature of PLA is about 150-180℃. In theory, PLA material has the potential to achieve heat resistance above 100℃. However, its crystallization ability is poor. Under general FFF printing conditions, the crystallization rate is low and the crystallinity of the printed parts is low, resulting in its heat resistance of about 60℃, which can only meet some usage scenarios with low requirements for material heat resistance. In addition, PLA material has poor crystallization ability and low T g , which is also the source of its excellent warping resistance.

[0004] At present, several common technical routes to improve the heat resistance of PLA material prints are:

[0005] (1) Significantly improve the crystallization ability / crystallization rate of PLA materials.

[0006] This technical route is based on improving the crystallization ability of PLA materials, increasing the crystallization nucleation and growth rates during the printing process of PLA materials, so that the printed parts can obtain a higher degree of crystallinity, thereby achieving an improvement in the heat resistance of the printed parts. During the FFF printing process, due to the existence of forced heat dissipation and air cooling, after the material is melted and extruded from the nozzle, the melt will undergo a rapid cooling process. The cooling rate is even as high as hundreds or thousands of °C / s in the initial stage. During the high-speed cooling process, it is difficult for PLA materials to obtain a higher degree of crystallinity. Moreover, even if the above-mentioned crystallization ability problem is solved, there will still be a problem of significantly reduced warpage resistance during the printing of PLA materials due to the formation of a higher degree of crystallinity. The mechanism is that during the cooling / cooling and shaping process of the polymer melt, the formation of a crystal structure causes a large degree of volume shrinkage of the material, which generates internal stress and causes warping of the printed parts.

[0007] (2) PLA material is blended and modified with other materials such as those with high heat resistance.

[0008] PLA materials and other high T g Or high crystallinity materials are blended and modified to prepare blended alloy materials. The improvement of heat resistance of this technical route generally depends on the addition amount of high heat-resistant components. If it is too low, the heat resistance effect will not be significantly improved. If it is too high, the adhesion between the printed layers will be seriously reduced due to the multi-phase system. At the same time, high T g The excessive introduction of highly crystalline materials will also lead to a decrease in the material's resistance to warping.

[0009] (3) Annealing and crystallization process of printed parts.

[0010] T g is the critical temperature at which the polymer molecular chain segments have the ability to move: T g Below the temperature, the polymer molecular chain segments are in a "frozen" state and have no ability to move; T g Above this temperature, the polymer molecular chain segments are "thawed" and have the ability to move. The polymer crystallization process is the process of orderly arrangement of molecular chains, which requires the chain segments to have the ability to move. g Temperatures above 100°C are the objective temperature conditions for polymer crystallization. One of the technical routes to improve the heat resistance of PLA prints is to perform T g Annealing heat treatment above temperature, its mechanism is to heat the PLA print to T g The above process enables the PLA molecular chain segments to move and crystallize, thus improving the crystallinity of the printed parts and further improving the heat resistance, which is called the "annealing crystallization process". gAs mentioned above, the molecular chain segments acquire the ability to move, and during the crystallization process, the printed parts are also at risk of deformation. Moreover, adding the annealing crystallization process will also increase the process cost. Summary of the invention

[0011] The purpose of this specification is to provide a 3D printing material, a 3D printing wire and a 3D printing method based on a three-phase system, so that the printing material suitable for the above-mentioned FFF printing technology can take into account both heat resistance and anti-warping performance.

[0012] The first aspect of the present specification provides a 3D printing material based on a three-phase system, including a first crystalline polymer, a second crystalline polymer and a third phase polymer; the second crystalline polymer includes a micro-nanoscale fiber structure, and the melting point of the second crystalline polymer is higher than the melting point of the first crystalline polymer; the third phase polymer includes at least one of a crystalline polymer and a non-crystalline polymer; when the third phase polymer includes a crystalline polymer, the melting point of the crystalline polymer is lower than the melting point of the second crystalline polymer; when the third phase polymer includes a non-crystalline polymer, the glass transition temperature of the non-crystalline polymer is lower than the melting point of the second crystalline polymer. The "micro-nanoscale fiber structure" involved in the above content means that the diameter of the fiber dispersed phase is micro-nanoscale, usually distributed in tens of nanometers, hundreds of nanometers, several micrometers to tens of micrometers; the micro-nanoscale fiber dispersed phase has a high aspect ratio, a high specific surface area, and excellent dispersion, so that it can form an intertwined microfiber network structure at a lower content of the fiber dispersed phase to reflect an excellent reinforcement effect.

[0013] In the 3D printing material based on the three-phase system provided in this specification, the first crystalline polymer is a continuous matrix phase, the second crystalline polymer is a fiber dispersed phase, and the third phase polymer is an auxiliary fiber-forming phase. In the above 3D printing material, the second crystalline polymer forms a continuously distributed fiber dispersed phase in the continuous matrix phase. The fiber dispersed phase with high specific surface area and high crystallinity can improve the crystallinity of the continuous matrix phase through crystallization heterogeneous nucleation during the 3D printing process to improve the heat resistance of the 3D printed part based on the continuous matrix phase as the main component. At the same time, the fiber dispersed phase can also play a certain skeleton support role for the continuous matrix phase, so that the 3D printed part based on the continuous matrix phase as the main component has excellent anti-warping performance. On the premise that the 3D printing material contains the first crystalline polymer and the second crystalline polymer, the present specification further introduces a third phase polymer into the 3D printing material, and uses the third polymer, the first crystalline polymer, and the second crystalline polymer to form a three-phase system, which can effectively increase the content of fiber structures with high aspect ratios in the fiber dispersed phase of the 3D printing material. As the content of fiber structures with high aspect ratios increases, the heat resistance of the 3D printing material can be further improved, so that the 3D printing material based on the three-phase system provided by the present specification has both excellent heat resistance and anti-warping properties. When using the above 3D printing material for 3D printing, a temperature lower than the melting point of the second crystalline polymer and higher than the melting point of the first crystalline polymer is selected as the printing temperature, so that at the printing temperature, the first crystalline polymer is melted, and the morphology of the fiber dispersed phase formed by the second crystalline polymer is not affected, and the fiber dispersed phase can preserve the micro-nanoscale fiber structure and the crystalline structure is not destroyed, ensuring that the fiber dispersed phase can maintain the advantages of high specific surface area and high crystallinity during the printing process.

[0014] In some embodiments, the third phase polymer includes a crystalline polymer, and the difference between the melting point of the second crystalline polymer and the melting point of the third phase crystalline polymer is no less than 20°C.

[0015] In some embodiments, the third phase polymer includes a non-crystalline polymer, and the difference between the melting point of the second crystalline polymer and the glass transition temperature of the third phase non-crystalline polymer is not less than 20°C.

[0016] In some embodiments, the third phase polymer comprises a crystalline polymer, and the melting point of the third phase crystalline polymer is lower than the melting point of the first crystalline polymer.

[0017] In some embodiments, the third phase polymer includes a non-crystalline polymer, and the glass transition temperature of the third phase non-crystalline polymer is lower than the melting point of the first crystalline polymer.

[0018] In some embodiments, the melting point of the second crystalline polymer is more than 30° C. higher than the melting point of the first crystalline polymer.

[0019] In some embodiments, the difference between the melting point of the second crystalline polymer and the melting point of the first crystalline polymer is no less than 50°C.

[0020] In some embodiments, the mass percentage of the second crystalline polymer in the 3D printing material is 3% to 40%.

[0021] In some embodiments, the mass percentage of the third phase polymer in the 3D printing material is 3% to 30%.

[0022] In some embodiments, the first crystalline polymer is polylactic acid.

[0023] In some embodiments, the second crystalline polymer includes at least one of a crystalline polyester material, a crystalline polyamide material, a crystalline polyether material, a crystalline polyolefin material, and a crystalline fluoropolymer.

[0024] In some embodiments, the second crystalline polymer includes at least one of polypropylene, polyethylene, polyisobutylene, polytetrafluoroethylene, polyvinylidene fluoride, polyphenylene sulfide, polyhexamethylene terephthalamide, polyethylene terephthalate, polybutylene terephthalate, polycaprolactam, and polyhexamethylene adipamide.

[0025] In some embodiments, the third phase polymer includes at least one of polyethylene, polypropylene, polystyrene, thermoplastic polyesters, polyamides, polycarbonates, and the like.

[0026] The second aspect of the present specification provides a method for preparing the 3D printing material as described above, comprising: treating a blend of a first crystalline polymer, a second crystalline polymer and a third phase polymer by an in-situ fiber-forming technology, so that the second crystalline polymer forms a fiber structure in the first crystalline polymer. The above 3D printing material is obtained by the in-situ fiber-forming technology, so that the fiber structure formed by the second crystalline polymer in the 3D printing material can be distributed in a relatively uniform manner in the continuous matrix phase formed by the first crystalline polymer.

[0027] A second aspect of the present specification provides a 3D printing wire, which is prepared from the 3D printing material based on the three-phase system as described above.

[0028] In some embodiments, the 3D printing material is subjected to single screw extrusion to form a wire; wherein the highest value of the extrusion temperature section is greater than the melting point of the first crystalline polymer and less than the melting point of the second crystalline polymer. By selecting the above extrusion temperature, the 3D printing wire can be obtained in the process of preparing the 3D printing wire without destroying the micro-nano fiber structure of the 3D printing material.

[0029] The second aspect of this specification provides the application of the 3D printing material based on the three-phase system as described above or the 3D printing wire as described above in 3D printing technology. The application here includes but is not limited to FFF printing.

[0030] In some embodiments, the temperature of 3D printing is lower than the melting point of the second crystalline polymer and higher than the melting point of the first crystalline polymer. Thus, during the 3D printing process, the micro-nanoscale fiber structure formed by the second crystalline polymer can be maintained, and the crystalline structure is not destroyed, and is directly introduced into the printed part, so that the second crystalline polymer in the 3D printing material will not cause the printed part to warp due to the internal stress of the crystal.

[0031] In some embodiments, a temperature higher than the melting point of the second crystalline polymer is used as the printing temperature for 3D printing. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of this specification, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 Schematic diagram of the process principle of in-situ fiber-forming composite materials;

[0034] Figure 2 A schematic diagram of a warping resistance printing model used in accordance with some embodiments of the present specification is shown;

[0035] Figure 3 This is a micrograph of the fiber structure in the 3D printing wire of Example 1 of this specification;

[0036] Figure 4 This is a graph showing the warpage test results of the 3D printed part of Example 1 of this specification;

[0037] Figure 5 This is a micrograph of the fiber structure in the 3D printing wire of Example 2 of this specification;

[0038] Figure 6 This is a graph showing the warpage test results of the 3D printed part of Example 2 of this specification;

[0039] Figure 7 This is a micrograph of the fiber structure in the 3D printing wire of Example 3 of this specification;

[0040] Figure 8 This is a graph showing the warpage test results of the 3D printed part of Example 3 of this specification;

[0041] Fig. 9 This is a micrograph of the fiber structure in the 3D printing wire of Example 4 of this specification;

[0042] Fig.10 This is a graph showing the warpage test results of the 3D printed part of Example 4 of this specification;

[0043] Fig.11 This is a micrograph of the fiber structure in the 3D printing wire of Example 5 of this specification;

[0044] Fig.12 This is a graph showing the warpage test results of the 3D printed part of Example 5 of this specification;

[0045] Fig.13 This is a micrograph of the fiber structure in the 3D printing wire of Example 6 of this specification;

[0046] Fig.14 This is a graph showing the warpage test results of the 3D printed part of Example 6 of this specification;

[0047] Fig.15 This is a micrograph of the fiber structure in the 3D printing wire of Example 7 of this specification;

[0048] Fig.16 This is a micrograph of the fiber structure in the 3D printing wire of Example 7 of this specification;

[0049] Fig.17 This is a graph showing the warpage test results of the 3D printed part of Comparative Example 1 of this specification;

[0050] Fig.18 This is a graph showing the warpage test results of the 3D printed part of Comparative Example 2 of this specification;

[0051] Fig.19 This is a micrograph of the fiber structure in the 3D printing wire of Comparative Example 3 of this specification;

[0052] Fig. 20 This is a graph showing the warpage test results of the 3D printed part of Comparative Example 3 of this specification;

[0053] Fig.21 This is a micrograph of the fiber structure in the 3D printing wire of Comparative Example 4 of this specification;

[0054] Fig. 22 This is a graph showing the warpage test results of the 3D printed part of Comparative Example 4 of this specification; DETAILED DESCRIPTION

[0055] The following description provides specific application scenarios and requirements of this specification, with the purpose of enabling those skilled in the art to make and use the contents of this specification. Various local modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of this specification. Therefore, this specification is not limited to the embodiments shown, but to the widest scope consistent with the claims.

[0056] In order to facilitate the understanding of this specification, the specification will be described more fully below with reference to the relevant drawings. The preferred embodiments of this specification are given in the drawings. However, this specification can be implemented in many different forms without departing from the core spirit of this specification and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of this specification more thorough and comprehensive.

[0057] The terms used herein are only used for the purpose of describing specific example embodiments and are not restrictive. For example, unless the context clearly indicates otherwise, as used herein, the singular forms "a", "an" and "the" may also include plural forms. When used in this specification, the terms "include", "comprise" and / or "contain" mean that the associated integers, steps, operations, elements and / or components exist, but do not exclude the existence of one or more other features, integers, steps, operations, elements, components and / or groups or that other features, integers, steps, operations, elements, components and / or groups may be added in the system / method.

[0058] In the present application, "X includes at least one of A, B, or C" means that X includes at least A, or X includes at least B, or X includes at least C. That is, X may include only any combination of A, B, and C, or may include any combination of A, B, and C and other possible contents / elements at the same time. The any combination of A, B, and C may be A, B, C, AB, AC, BC, or ABC.

[0059] In view of the following description, these and other features of this specification, as well as the operation and function of the relevant elements of the structure, and the economy of the combination and manufacture of the parts can be significantly improved. The description also includes all figures and text in the drawings referenced in this specification, all of which form a part of this specification. However, it should be clearly understood that the drawings are only for the purpose of illustration and description and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale. At the same time, for the convenience of description, the terms that may appear in this specification are first explained as follows.

[0060] In-situ fiberization technology refers to a fiber-reinforced material processing method in which after blending multiple incompatible polymers, the dispersed phase in the two-phase system is stretched or sheared by applying an external force field, and the phase morphology is fiberized to form oriented micro-nanoscale fibers in the continuous phase. This fiber-reinforced composite material that uses a special processing technology to form a fiber phase from the dispersed phase "in situ" is figuratively called "in-situ Micro Fibrillation Composites" (iMFC). The principle diagram is shown below. Figure 1 shown.

[0061] A crystalline polymer refers to a polymer that has at least one component that is crystallizable and has a sufficient sequence length to generate crystals. In a crystalline polymer, the region where the molecules are arranged regularly is the crystalline region, and the region where the molecules are arranged disorderly is the amorphous region. The percentage of the crystalline region is called the crystallinity. For ease of description, crystalline polymer is used in this specification to represent a crystalline polymer that has both crystalline and amorphous regions. It should be noted that the first crystalline polymer and the second crystalline polymer in this specification are both crystalline polymers, and the types of crystals contained in the first crystalline polymer and the second crystalline polymer are different. When the third phase polymer includes a crystalline polymer, the types of crystals contained in the crystalline polymer, the first crystalline polymer, and the second crystalline polymer included in the third phase polymer are different from each other.

[0062] Amorphous polymers are polymers with disordered molecular arrangement and no obvious crystal structure. Amorphous polymers do not have a fixed melting point, and their melting process is expressed as a temperature range rather than a fixed temperature point. For amorphous polymers, the "glass transition temperature" is more commonly used, which refers to the temperature at which the molecules change from a frozen state to a state of motion.

[0063] According to the first aspect of the present specification, a 3D printing material based on a three-phase system is provided, including a first crystalline polymer, a second crystalline polymer and a third phase polymer; the second crystalline polymer includes a micro-nanoscale fiber structure, and the melting point of the second crystalline polymer is higher than the melting point of the first crystalline polymer; the third phase polymer includes at least one of a crystalline polymer and a non-crystalline polymer; when the third phase polymer includes a crystalline polymer, the melting point of the crystalline polymer is lower than the melting point of the second crystalline polymer; when the third phase polymer includes a non-crystalline polymer, the glass transition temperature of the non-crystalline polymer is lower than the melting point of the second crystalline polymer. The "micro-nanoscale fiber structure" involved in the above content means that the diameter of the fiber dispersed phase is micro-nanoscale, usually distributed in tens of nanometers, hundreds of nanometers, several micrometers to tens of micrometers; the micro-nanoscale fiber dispersed phase has a high aspect ratio, a high specific surface area, and excellent dispersion, so that it can form an intertwined microfiber network structure at a lower content of the fiber dispersed phase to reflect an excellent reinforcement effect.

[0064] In the 3D printing material based on the three-phase system provided in this specification, the first crystalline polymer is a continuous matrix phase, the second crystalline polymer is a fiber dispersed phase, and the third phase polymer is an auxiliary fiber-forming phase. In the above 3D printing material, the second crystalline polymer forms a continuously distributed fiber dispersed phase in the continuous matrix phase. The fiber dispersed phase with high specific surface area and high crystallinity can improve the crystallinity of the continuous matrix phase through crystallization heterogeneous nucleation during the 3D printing process to improve the heat resistance of the 3D printed part based on the continuous matrix phase as the main component. At the same time, the fiber dispersed phase can also play a certain skeleton support role for the continuous matrix phase, so that the 3D printed part based on the continuous matrix phase as the main component has excellent anti-warping performance. On the premise that the 3D printing material contains the first crystalline polymer and the second crystalline polymer, the present specification further introduces a third phase polymer into the 3D printing material, and uses the third polymer, the first crystalline polymer, and the second crystalline polymer to form a three-phase system, which can effectively increase the content of fiber structures with high aspect ratios in the fiber dispersed phase of the 3D printing material. As the content of fiber structures with high aspect ratios increases, the heat resistance of the 3D printing material can be further improved, so that the 3D printing material based on the three-phase system provided by the present specification has both excellent heat resistance and anti-warping properties. When using the above 3D printing material for 3D printing, a temperature lower than the melting point of the second crystalline polymer and higher than the melting point of the first crystalline polymer is selected as the printing temperature, so that at the printing temperature, the first crystalline polymer is melted, and the morphology of the fiber dispersed phase formed by the second crystalline polymer is not affected, and the fiber dispersed phase can preserve the micro-nanoscale fiber structure and the crystalline structure is not destroyed, ensuring that the fiber dispersed phase can maintain the advantages of high specific surface area and high crystallinity during the printing process.

[0065] In some embodiments, the third phase polymer includes a crystalline polymer, and the difference between the melting point of the second crystalline polymer and the melting point of the third phase crystalline polymer is no less than 20°C.

[0066] In some embodiments, the third phase polymer includes a non-crystalline polymer, and the difference between the melting point of the second crystalline polymer and the glass transition temperature of the third phase non-crystalline polymer is not less than 20°C.

[0067] In some embodiments, the third phase polymer comprises a crystalline polymer, and the melting point of the third phase crystalline polymer is lower than the melting point of the first crystalline polymer.

[0068] In some embodiments, the third phase polymer includes a non-crystalline polymer, and the glass transition temperature of the third phase non-crystalline polymer is lower than the melting point of the first crystalline polymer.

[0069] In some embodiments, the melting point of the second crystalline polymer is more than 30° C. higher than the melting point of the first crystalline polymer.

[0070] In some embodiments, the difference between the melting point of the second crystalline polymer and the melting point of the first crystalline polymer is no less than 50°C.

[0071] In some embodiments, the mass percentage of the second crystalline polymer in the 3D printing material is 3% to 40%. The content of the second crystalline polymer in the 3D printing material will affect the processing performance and heat resistance enhancement effect of the material. Controlling the mass percentage of the second crystalline polymer in the 3D printing material within the above range can not only give full play to the heterogeneous nucleation effect of the second crystalline polymer, so that the crystallinity of the 3D printed part is significantly improved, but also help the first crystalline polymer to maintain good printing performance and facilitate the uniform distribution of the fiber dispersed phase in the continuous matrix phase. If the content of the second crystalline polymer is lower than the above range, the crystallinity of the 3D printed part will decrease; if the content of the second crystalline polymer is higher than the above range, the printing performance of the first crystalline polymer will decrease, the dispersion uniformity of the second crystalline polymer in the first crystalline polymer will also decrease, and the second crystalline polymer will be more likely to agglomerate. The mass percentage of the second crystalline polymer in the 3D printing material can be any value between 3% and 40%. For example, 3%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35%, 36%, 37%, 38%, 39% or 40%, but are not limited to the listed values, other values ​​not listed within the numerical range are also applicable.

[0072] In some other embodiments, the mass percentage of the second crystalline polymer in the 3D printing material may also be any value between 3% and 300%.

[0073] In some other embodiments, the mass percentage of the second crystalline polymer in the 3D printing material may also be any value between 5% and 15%.

[0074] In some embodiments, the mass percentage of the third phase polymer in the 3D printing material is 5% to 30%. For example, the mass percentage of the third phase polymer can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29% or 30%, etc., but is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0075] In some embodiments, the first crystalline polymer is polylactic acid (PLA). As one of the most common materials for FFF printing, which is one of the mainstream technical forms in the current extrusion 3D printing technology, polylactic acid has the best feasibility with the above-mentioned embodiments of this specification, and can solve the long-term technical pain points of the high heat resistance technical route of polylactic acid material 3D printing.

[0076] In some embodiments, the second crystalline polymer includes at least one of a crystalline polyester material, a crystalline polyamide material, a crystalline polyether material, a crystalline polyolefin material, or a crystalline fluoropolymer.

[0077] In some embodiments, the second crystalline polymer includes at least one of polypropylene (PP), polyethylene (PE), polyisobutylene (PIB), polytetrafluoroethylene (PTEE), polyvinylidene fluoride (PVDF), polyphenylene sulfide (PPS), polyhexamethylene terephthalamide (PA6T), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycaprolactam (nylon 6), and polyhexamethylene adipamide (nylon 66).

[0078] In some embodiments, the third phase polymer includes at least one of polyethylene (PE), polypropylene (PP), polystyrene (PS), thermoplastic polyester, polyamide, polycarbonate, and the like.

[0079] According to the second aspect of the present specification, a method for preparing the 3D printing material as described above includes: treating a blend of a first crystalline polymer, a second crystalline polymer and a third phase polymer by an in-situ fiber-forming technology, so that the second crystalline polymer forms a fiber structure in the first crystalline polymer. The above 3D printing material is obtained by the in-situ fiber-forming technology, so that the fiber structure formed by the second crystalline polymer in the 3D printing material can be distributed in a relatively good uniformity in the continuous matrix phase formed by the first crystalline polymer.

[0080] According to a third aspect of the present specification, a 3D printing wire is provided, which is prepared from the 3D printing material based on the three-phase system as described above.

[0081] In some embodiments, the 3D printing material is subjected to single screw extrusion to form a wire; wherein the highest value of the extrusion temperature section is greater than the melting point of the first crystalline polymer and less than the melting point of the second crystalline polymer. By selecting the above extrusion temperature, the 3D printing wire can be obtained in the process of preparing the 3D printing wire without destroying the micro-nano fiber structure of the 3D printing material.

[0082] According to a fourth aspect of the present specification, there is provided an application of the 3D printing material based on the three-phase system or the 3D printing wire as described above in 3D printing technology. The application here includes but is not limited to FFF printing.

[0083] In some embodiments, the temperature of 3D printing is lower than the melting point of the second crystalline polymer and higher than the melting point of the first crystalline polymer. Thus, during the 3D printing process, the micro-nanoscale fiber structure formed by the second crystalline polymer can be maintained, and the crystalline structure is not destroyed, and is directly introduced into the printed part, so that the second crystalline polymer in the 3D printing material will not cause the printed part to warp due to the internal stress of the crystal.

[0084] In some embodiments, a temperature higher than the melting point of the second crystalline polymer is used as the printing temperature for 3D printing.

[0085] The 3D printing materials and preparation methods in the above embodiments are designed based on the material defects existing in the 3D printing behavior. In the existing printing material (such as polylactic acid) as the first crystalline polymer (continuous matrix phase), a high melting point second crystalline polymer (fiber dispersion phase) and a third phase polymer (auxiliary fiber phase) are introduced therein to prepare a three-phase system 3D printing material. In the 3D printing material obtained thereby, there is a micro-nanoscale fiber structure formed by the second crystalline polymer. Under the action of the third phase polymer, these fiber structures have better fiber quality, wherein the fiber structure with a high aspect ratio has a high content. In the fiber structure formed by the second crystalline polymer, the fiber structure with a high aspect ratio has a higher specific surface area, which can better play the role of crystallization heterogeneous nucleation, thereby more effectively promoting the crystallinity of the first crystalline polymer. At the same time, the micro-nanoscale fiber structure can be used as a reinforcing phase, and the fiber structure with a high aspect ratio is more conducive to forming a microfiber mesh structure in the first crystalline polymer under the condition of low content of the second crystalline polymer, thereby having an excellent reinforcing effect on the printed part and improving its anti-warping performance. In summary, based on the high crystallinity and high heat resistance of the micro-nanoscale fiber structure, the 3D printing material provided in this specification has both good heat resistance and excellent anti-warping properties.

[0086] In the process of 3D printing using the above-mentioned 3D printing material, printing is performed below the melting point temperature of the second crystalline polymer. Thus, the micro-nanoscale fiber structure of the second crystalline polymer can be "preserved" and at the same time, the crystalline structure of the second crystalline polymer can be directly introduced into the printed part without being destroyed, and the printed part will not warp due to the internal crystalline stress of the second crystalline polymer.

[0087] The features and performance of the present invention are further described in detail below in conjunction with the embodiments and comparative examples.

[0088] The first crystalline polymer in the wire is removed by an organic solvent, and the second crystalline polymer is extracted. The fiber lengths of more than 100 fibers are measured and averaged to obtain the number average length LM, and the fiber diameters of more than 10 fibers are measured and averaged to obtain the diameter D. The aspect ratio of the fiber is defined as: L M Divide by the diameter D, that is, use the following formula to calculate:

[0089]

[0090] The anti-warping printing test method in the embodiments and comparative examples of this specification is as follows:

[0091] Under a preset target external environment, the 3D printing material of the target size is printed on a target base plate using a target process flow to form a target part of a cuboid of target size (L×W×H). Figure 2 A schematic diagram of a target printing model used in some embodiments of the present specification is shown, wherein the side of the target part contacting the target base plate is the bottom surface, and its length is L, width is W, and height is H; after the rectangular part is cooled, the heights of the four corners of the bottom surface of the rectangular part away from the target base plate (that is, the distances between the four corners and the highest point of the target base plate) are measured, and the average value h is calculated; then the warp value of the 3D material is defined as: h value divided by the height H of the target part, that is, calculated using the following formula:

[0092]

[0093] Obviously, when L, W, and H are constant, the smaller the average height h of the four corners of the bottom surface of the cuboid from the ground after cooling, the smaller the deformation of the part during cooling, and the smaller the warping rate. In this specification, the anti-warping performance of the printing can be measured by the deformation generated by the 3D printing material during the printing process. The smaller the warping degree of the 3D printed product after printing, the better the anti-warping performance of the 3D printing material.

[0094] It is understandable that for the same material, under different standard sizes and different external cooling environments, the cooling speed and uniformity of the material are different, so the warpage may also be different.

[0095] According to some embodiments of the present application, the preset target external environment may include: the printing material is PLA wire, the wire diameter specification is 1.75mm±0.05mm, the printing nozzle diameter is 0.4mm, the slicing parameters during printing are line width 0.4mm, layer height 0.2mm, wall layer number (shell) 13, and printing speed 100mm / s. In addition, the printing temperature in this embodiment is matched as appropriate according to the material type and extrusion characteristics, for example, the printing temperature of PLA material is 190~230℃, and the base plate temperature is 30~60℃.

[0096] For example, if the target part (printed part) is 150 mm long and 20 mm high, and the average warping height h of the four corners after cooling is 1 mm, the Warp curvature is calculated to be 5%; when the model is severely warped and the height H does not reach 20 mm due to printing failure, it is calculated according to the actual printable height. For example, if the target part (printed part) is 150 mm long and 10 mm high, and the average warping height h of the four corners after cooling is 1 mm, the Warp curvature is calculated to be 10%.

[0097] Example 1

[0098] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0099] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0100] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point T m1 170℃), with polyphenylene sulfide PPS as the second crystalline polymer (fiber dispersed phase, melting point T m2 285℃), with polypropylene PP as the third phase polymer (auxiliary fiber-forming phase, melting point T m3 is 165°C).

[0101] In this embodiment, the amounts of PLA, PPS and PP are such that, in the 3D printing material composed of the three, the mass content of the second crystalline polymer PPS is 25%, and the mass content of the third phase polymer PP is 10%. After PLA, PPS and PP are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-300°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0102] 2) Processing the prepared 3D printing material into 3D printing filament.

[0103] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0104] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Figure 3 As shown, the fiber aspect ratio is 121.3, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0105] 3) Perform FFF printing test on the 3D printing filament.

[0106] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Figure 4 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Figure 4 As shown, the warpage rate of the printed part tested was 0.47%, and the printed part had no warping as a whole, showing excellent anti-warping properties.

[0107] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 166.5°C, indicating good heat resistance.

[0108] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0109] Example 2

[0110] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0111] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0112] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point T m1 170℃), with polyphenylene sulfide PPS as the second crystalline polymer (fiber dispersed phase, melting point T m2 285℃), with polyethylene PE as the third phase polymer (auxiliary fiber-forming phase, melting point T m3 is 130°C).

[0113] In this embodiment, the amounts of PLA, PPS and PE are such that in the 3D printing material composed of the three, the mass content of the second crystalline polymer PPS is 20%, and the mass content of the third phase polymer PE is 12%. After PLA, PPS and PE are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-300°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0114] 2) Processing the prepared 3D printing material into 3D printing filament.

[0115] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0116] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Figure 5 As shown, the fiber aspect ratio is 115.0, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0117] 3) Perform FFF printing test on the 3D printing filament.

[0118] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Figure 6 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Figure 6 As shown, the warpage rate of the printed part tested was 0.52%, and the printed part had no warpage as a whole, showing excellent anti-warping properties.

[0119] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 163.4°C, indicating good heat resistance.

[0120] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0121] Example 3

[0122] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0123] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0124] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point T m1 170℃), with polyphenylene sulfide PPS as the second crystalline polymer (fiber dispersed phase, melting point T m2 285℃), with polyethylene terephthalate-1,4-cyclohexane dimethanol PETG as the third phase polymer (auxiliary fiber-forming phase, glass transition temperature T g3 is 78°C).

[0125] In this embodiment, the amount of PLA, PPS and PETG is such that in the 3D printing material composed of the three, the mass content of the second crystalline polymer PPS is 10%, and the mass content of the third phase polymer PETG is 7%. After PLA, PPS and PETG are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-300°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0126] 2) Processing the prepared 3D printing material into 3D printing filament.

[0127] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0128] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Figure 7 As shown, the fiber aspect ratio is 96.4, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0129] 3) Perform FFF printing test on the 3D printing filament.

[0130] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Figure 8 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Figure 8 As shown, the warpage rate of the printed part tested was 0.65%, and the printed part had no warpage as a whole, showing excellent anti-warping properties.

[0131] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 157.0°C, indicating good heat resistance.

[0132] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0133] Example 4

[0134] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0135] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0136] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point T m1 170℃), with polyphenylene sulfide PPS as the second crystalline polymer (fiber dispersed phase, melting point T m2 285℃), with polystyrene as the third phase polymer (auxiliary fiber-forming phase, glass transition temperature T g3 is 100°C).

[0137] In this embodiment, the amounts of PLA, PPS and PS are such that in the 3D printing material composed of the three, the mass content of the second crystalline polymer PPS is 17%, and the mass content of the third phase polymer PS is 15%. After PLA, PPS and PS are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-300°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0138] 2) Processing the prepared 3D printing material into 3D printing filament.

[0139] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0140] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Fig. 9 As shown, the fiber aspect ratio is 90.2, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0141] 3) Perform FFF printing test on the 3D printing filament.

[0142] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Fig.10 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Fig.10 As shown, the warpage rate of the printed part tested was 0.71%, and the printed part had no warpage as a whole, showing excellent anti-warping properties.

[0143] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 150.1°C, indicating good heat resistance.

[0144] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0145] Example 5

[0146] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0147] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0148] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point T m1 170°C), with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T m2 310℃), with polystyrene as the third phase polymer (auxiliary fiber-forming phase, glass transition temperature T g3 is 100°C).

[0149] In this embodiment, the amounts of PLA, PA6T and PS are sufficient. In the 3D printing material composed of the three, the mass content of the second crystalline polymer PA6T is 15%, and the mass content of the third phase polymer PS is 6%. After PLA, PA6T and PS are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-330°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0150] 2) Processing the prepared 3D printing material into 3D printing filament.

[0151] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0152] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Fig.11 As shown, the fiber aspect ratio is 87.6, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0153] 3) Perform FFF printing test on the 3D printing filament.

[0154] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Fig.12 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Fig.12 As shown, the warpage rate of the printed part tested was 0.85%, and the printed part had no warpage as a whole, showing excellent anti-warping properties.

[0155] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 140.6°C, indicating good heat resistance.

[0156] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0157] Example 6

[0158] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0159] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0160] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point T m1 170°C), with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T m2 310℃), with polyethylene terephthalate-1,4-cyclohexane dimethanol PETG as the third phase polymer (auxiliary fiber-forming phase, glass transition temperature T g3 is 78°C).

[0161] In this embodiment, the amount of PLA, PA6T and PETG is sufficient. In the 3D printing material composed of the three, the mass content of the second crystalline polymer PA6T is 12%, and the mass content of the third phase polymer PETG is 20%. After PLA, PA6T and PETG are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-330°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0162] 2) Processing the prepared 3D printing material into 3D printing filament.

[0163] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0164] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Fig.13 As shown, the fiber aspect ratio is 92.9, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0165] 3) Perform FFF printing test on the 3D printing filament.

[0166] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Fig.14 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Fig.14 As shown, the warpage rate of the printed part tested was 0.68%, and the printed part had no warping as a whole, showing excellent anti-warping properties.

[0167] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 144.3°C, indicating good heat resistance.

[0168] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0169] Example 7

[0170] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0171] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0172] With polylactic acid PLA as the first crystalline polymer (continuous matrix phase, melting point Tm1 170°C), with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T m2 310℃), with polyethylene PE as the third phase polymer (auxiliary fiber-forming phase, melting point T m3 is 130°C).

[0173] In this embodiment, the amount of PLA, PA6T and PE is sufficient. In the 3D printing material composed of the three, the mass content of the second crystalline polymer PA6T is 30%, and the mass content of the third phase polymer PE is 17%. After PLA, PA6T and PE are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-330°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0174] 2) Processing the prepared 3D printing material into 3D printing filament.

[0175] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0176] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Fig.15 As shown, the fiber aspect ratio is 106.7, indicating that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is better.

[0177] 3) Perform FFF printing test on the 3D printing filament.

[0178] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Fig.16 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Fig.16 As shown, the warpage rate of the printed part tested was 0.60%, and the printed part had no warpage as a whole, showing excellent anti-warpage properties.

[0179] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 159.8°C, indicating good heat resistance.

[0180] It can be seen that the 3D printing material prepared in this embodiment has both excellent printing anti-warping properties and heat resistance of printed parts.

[0181] Comparative Example 1

[0182] This comparative example uses the same PLA material as in Example 1 to prepare a 3D printing material.

[0183] PLA raw material particles were used to prepare PLA wires by single screw extrusion molding, and the single screw in-and-out molding process used in this comparative example adopted the same process conditions as the single screw in-and-out molding process in Example 1. The PLA wires thus prepared contained neither the second crystalline polymer nor the third phase polymer.

[0184] The PLA filament prepared in this comparative example was used to perform an FFF printing test, and the process conditions were consistent with the FFF printing test involved in Example 1. Fig.17 The finished product after printing is shown in the figure. Fig.17 As shown, the printed part has no warping as a whole and has excellent anti-warping properties.

[0185] At the same time, the printed part was subjected to a Vicat heat resistance test using the GB / T 1633-2000 thermoplastic Vicat softening temperature (VST) determination, the A120 method, a force of 10 N, and a heating rate of 120°C / h. The test showed that the Vicat heat resistance temperature of the printed part was 61.7°C, indicating that the heat resistance of the printed part prepared in this comparative example was relatively low.

[0186] It can be seen that compared with the 3D printing materials prepared in Examples 1 to 7, the heat resistance of the PLA printing material provided in Comparative Example 1 is significantly poorer, and it is impossible for the printed parts prepared using it to have both excellent printing anti-warping and printed part heat resistance.

[0187] Comparative Example 2

[0188] This comparative example uses the same PLA material as in Example 1, and adds an organic hydrazide crystallization nucleating agent at 1% by weight relative to the polylactic acid material. The same twin-screw mixing process and single-screw extrusion wire processing process as in Example 1 are used to prepare 3D printing wire.

[0189] The 3D printing filament prepared in this comparative example was used to perform an FFF printing test, and the process conditions were consistent with the FFF printing test involved in Example 1. Fig.18 The finished product after printing is shown in the figure. Fig.18 As shown, the printed part has significant warping, and the warping rate is 17.3% as tested, which shows poor anti-warping property compared with Examples 1 to 7.

[0190] At the same time, the printed parts were subjected to a Vicat heat resistance test using GB / T 1633-2000 Thermoplastic Vicat Softening Temperature (VST) determination, A120 method, a force of 10N, and a heating rate of 120°C / h. The test showed that the Vicat heat resistance temperature of the printed parts was 145.3°C.

[0191] It can be seen that the PLA printing material provided in Comparative Example 2 cannot make the printed parts made using it have both excellent printing anti-warping properties and printed part heat resistance.

[0192] Comparative Example 3

[0193] This comparative example specifically comprises the following steps:

[0194] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0195] As in Examples 1 to 4, polylactic acid PLA is used as the first crystalline polymer (continuous matrix phase, melting point T m1 170℃), with polyphenylene sulfide PPS as the second crystalline polymer (fiber dispersed phase, melting point T m2 The PLA wire obtained does not contain a third phase polymer.

[0196] In this embodiment, the amount of PLA and PPS is sufficient, and in the 3D printing material composed of the two, the mass content of the second crystalline polymer PPS is 25%. After PLA and PPS are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-300°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0197] 2) Processing the prepared 3D printing material into 3D printing filament.

[0198] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0199] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Fig.19 As shown, the fiber aspect ratio is 36.4, which indicates that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is poor.

[0200] 3) Perform FFF printing test on the 3D printing filament.

[0201] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Fig. 20 The printout shown is a rectangular parallelepiped with length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. Fig. 20 As shown, the warpage rate of the printed part tested was 8.5%, and the warpage resistance of the printed part was poor.

[0202] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 86.1°C, indicating poor heat resistance.

[0203] It can be seen that compared with the 3D printing materials prepared in Examples 1 to 4 in which the third phase polymer is introduced, the 3D printing material provided by the two-phase polymer in Comparative Example 3 has significantly poorer anti-warping and heat resistance, and it is impossible for the printed parts prepared using it to have both excellent anti-warping properties and heat resistance.

[0204] Comparative Example 4

[0205] This comparative example specifically comprises the following steps:

[0206] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0207] As in Examples 5 to 7, polylactic acid PLA is used as the first crystalline polymer (continuous matrix phase, melting point T m1 170°C), with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T m2 The PLA wire obtained does not contain a third phase polymer.

[0208] In this embodiment, the amount of PLA and PA6T is sufficient, and in the 3D printing material composed of the two, the mass content of the second crystalline polymer PA6T is 30%. After PLA and PA6T are mixed in proportion, a twin-screw extrusion process is used for mixing, the processing temperature is 220-330°C, the extruded material strips are pulled, cooled and shaped in a normal temperature water tank, and pelletized by a pelletizer to prepare the 3D printing material.

[0209] 2) Processing the prepared 3D printing material into 3D printing filament.

[0210] The specific operation is: single-screw extrusion molding is performed on the above-mentioned 3D printing material at a temperature of 160-240°C to prepare the 3D printing wire.

[0211] The fiber structure of the obtained 3D printing wire was observed under a microscope. The micro-nanoscale fiber structure is as follows Fig.21 As shown, the fiber aspect ratio is 32.1, which indicates that in this embodiment, the fiber-forming quality of the second crystalline polymer in the 3D printing wire is poor.

[0212] 3) Perform FFF printing test on the 3D printing filament.

[0213] The prints obtained by FFF printing were subjected to anti-warping printing test at a temperature of 210°C. Fig. 22 The print shown in the figure cannot be printed with a height of H = 20 mm due to the serious warping of the print. Therefore, the final cuboid has a length of L = 150 mm, a width of W = 9.6 mm, and a height of H = 10 mm. Fig. 22 As shown, the warpage rate of the printed part tested was 24.3%, and the warpage resistance of the printed part was poor.

[0214] At the same time, the printed parts were subjected to a Vicat heat resistance test using the GB / T 1633-2000 Vicat softening temperature (VST) of thermoplastics, the A120 method, a force of 10N, and a heating rate of 120°C / h. The Vicat heat resistance temperature of the printed parts was measured to be 77.7°C, indicating relatively low heat resistance.

[0215] It can be seen that compared with the 3D printing materials prepared in Examples 5 to 7 in which the third phase polymer is introduced, the 3D printing material provided by the two-phase polymer in Comparative Example 3 has significantly poorer anti-warping and heat resistance, and it is impossible for the printed parts prepared using it to have both excellent anti-warping properties and heat resistance.

[0216] In summary, after reading this detailed disclosure, it will be apparent to those skilled in the art that the foregoing detailed disclosure may be presented only by way of example and may not be limiting. Although not explicitly stated herein, it will be appreciated by those skilled in the art that this specification is intended to encompass various reasonable changes, improvements, and modifications to the embodiments. These changes, improvements, and modifications are intended to be proposed by this specification and are within the spirit and scope of the exemplary embodiments of this specification.

[0217] The above is a description of a specific embodiment of the specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recorded in the claims can be performed in an order different from that in the embodiments and still achieve the desired results. In addition, the processes depicted in the drawings do not necessarily require the specific order or continuous order shown to achieve the desired results. In some embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0218] In addition, certain terms in this specification have been used to describe embodiments of this specification. For example, "one embodiment", "an embodiment" and / or "some embodiments" mean that a particular feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of this specification. Therefore, it can be emphasized and should be understood that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. In addition, specific features, structures or characteristics may be appropriately combined in one or more embodiments of this specification.

[0219] It should be understood that in the foregoing description of the embodiments of this specification, in order to help understand a feature and for the purpose of simplifying this specification, this specification sometimes combines various features in a single embodiment, drawing or its description. Alternatively, this specification also disperses various features in multiple embodiments of this specification. However, this does not mean that the combination of these features is necessary. When reading this specification, it is entirely possible for those skilled in the art to extract some of the features and understand them as separate embodiments. In other words, the embodiments in this specification can also be understood as the integration of multiple secondary embodiments. This is also true when the content of each secondary embodiment is less than all the features of a single aforementioned disclosed embodiment.

Claims

1. A 3D printing material based on a three-phase system, characterized in that: include: a first crystalline polymer; a second crystalline polymer, comprising a micro-nanoscale fiber structure, wherein the melting point of the second crystalline polymer is higher than the melting point of the first crystalline polymer; as well as The third phase polymer includes at least one of a crystalline polymer and a non-crystalline polymer; wherein the melting point of the crystalline polymer is lower than the melting point of the second crystalline polymer; and the glass transition temperature of the non-crystalline polymer is lower than the melting point of the second crystalline polymer.

2. The 3D printing material according to claim 1, characterized in that: The difference between the melting point of the second crystalline polymer and the melting point of the third phase crystalline polymer is not less than 20°C; The difference between the melting point of the second crystalline polymer and the glass transition temperature of the third phase non-crystalline polymer is not less than 20°C.

3. The 3D printing material according to claim 1, characterized in that: The melting point of the third phase crystalline polymer is lower than the melting point of the first crystalline polymer; The glass transition temperature of the third phase non-crystalline polymer is lower than the melting point of the first crystalline polymer.

4. The 3D printing material according to claim 1, characterized in that: The melting point of the second crystalline polymer is higher than the melting point of the first crystalline polymer by 30° C. or more.

5. The 3D printing material according to claim 4, characterized in that: The difference between the melting point of the second crystalline polymer and the melting point of the first crystalline polymer is not less than 50°C.

6. The 3D printing material according to claim 1, characterized in that: The mass percentage of the second crystalline polymer in the 3D printing material is 3% to 40%.

7. The 3D printing material according to claim 1, characterized in that: The mass percentage of the third phase polymer in the 3D printing material is 3% to 30%.

8. The 3D printing material according to any one of claims 1 to 7, characterized in that: The first crystalline polymer is polylactic acid.

9. The 3D printing material according to any one of claims 1 to 7, characterized in that: The second crystalline polymer includes at least one of a crystalline polyester material, a crystalline polyamide material, a crystalline polyether material, a crystalline polyolefin material or a crystalline fluorine-containing polymer.

10. The 3D printing material according to claim 9, characterized in that: The second crystalline polymer includes at least one of polypropylene, polyethylene, polyisobutylene, polytetrafluoroethylene, polyvinylidene fluoride, polyphenylene sulfide, polyhexamethylene terephthalamide, polyethylene terephthalate, polybutylene terephthalate, polycaprolactam, or polyhexamethylene adipamide.

11. The 3D printing material based on the three-phase system according to any one of claims 1 to 7, characterized in that: The third phase polymer includes at least one of polyethylene, polypropylene, polystyrene, thermoplastic polyester, polyamide, polycarbonate, and the like.

12. A method for preparing a 3D printing material according to any one of claims 1 to 10, characterized in that: include: heating the blend of the first crystalline polymer, the second crystalline polymer, and the third phase polymer to a temperature above the melting point of the second crystalline polymer; The blend is physically stretched during the process of cooling and solidifying the blend, so that the second crystalline polymer forms the fiber structure in the first crystalline polymer after the blend is cooled.

13. A 3D printing wire, characterized in that: The 3D printing wire is prepared from the 3D printing material based on the three-phase system as described in any one of claims 1 to 11.

14. Use of the 3D printing material based on the three-phase system according to any one of claims 1 to 10 or the 3D printing wire according to claim 13 in 3D printing technology.

15. The use according to claim 14, wherein a temperature lower than the melting point of the second crystalline polymer and higher than the melting point of the first crystalline polymer is used as the printing temperature for 3D printing.

16. The use according to claim 14, wherein a temperature higher than the melting point of the second crystalline polymer is used as the printing temperature for 3D printing.

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