Three-phase system-based 3D printing material, 3D printing filament, and 3D printing method

Abstract

Provided in the present description is a three-phase system-based 3D printing material, comprising a first crystalline polymer, a second crystalline polymer and a third phase polymer. The second crystalline polymer comprises a micro-nano fiber structure, the melting point of the second crystalline polymer being higher than the melting point 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 being lower than the melting point of the second crystalline polymer, the glass transition temperature of the amorphous polymer being lower than the melting point of the second crystalline polymer. In the present description, the presence of the third phase polymer can increase the content of fiber structures having a high aspect ratio, and, on the basis of the advantages of high specific surface area, high crystallinity and high heat resistance, these fiber structures enable printed pieces obtained by 3D printing using the 3D printing material to have both high heat resistance and high anti-warp property.

Description

A 3D printing material, 3D printing filament, and 3D printing method based on a three-phase system Technical Field

[0001] This specification belongs to the field of 3D printing technology, specifically relating to a 3D printing material and 3D printing filament based on a three-phase system, as well as a 3D printing method. Background Technology

[0002] Material-extrusion based 3D printing (ME-3DP) is one of the most mainstream forms of additive manufacturing technology for polymer materials. Its principle involves melting polymer materials at high temperatures to achieve melt flowability, and then depositing the melt layer by layer in a metered manner to form a shape. Within extrusion 3D printing technology, filament fabrication (FFF) is one of the mainstream techniques.

[0003] In FFF printing, some materials suffer from poor heat resistance due to their low crystallinity, thus limiting their application scenarios. For example, polylactic acid (PLA) is currently the most versatile printing material in FFF printing. Its excellent anti-warping properties, interlayer adhesion, and fully biodegradable nature make it one of the "most usable and most market-accepted" materials. However, with the expansion of FFF printing applications, the relatively low heat resistance of PLA-printed parts (softening temperature of approximately 60°C) has become one of its long-standing pain points. Specifically, the glass transition temperature T0 of PLA material... g Approximately 60℃, melting temperature T m The theoretical heat resistance of PLA material is approximately 150–180℃, and it has the potential to achieve heat resistance above 100℃. However, its crystallization ability is poor. Under typical FFF printing conditions, the crystallization rate is low, resulting in low crystallinity of the printed parts. This limits its heat resistance to around 60℃, which is only suitable for some applications with lower requirements for material heat resistance. Furthermore, PLA material's poor crystallization ability and low Tg... g This is also the source of its excellent resistance to warping.

[0004] Currently, the common technical approaches to improving the heat resistance of PLA material printed parts are as follows:

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

[0006] This technical approach is based on improving the crystallization ability of PLA materials, increasing the nucleation and growth rate of crystals during the PLA printing process, thereby achieving higher crystallinity in the printed parts and improving their heat resistance. In FFF printing, due to forced air cooling, the material undergoes rapid cooling after being extruded from the nozzle, with cooling rates reaching hundreds or even thousands of °C / s in the initial stage. During this rapid cooling, PLA materials struggle to achieve high crystallinity. Furthermore, even if the crystallization ability issue is resolved, the high crystallinity of PLA materials during printing can lead to a significant reduction in warpage resistance. The mechanism is that during the cooling / settling process of the polymer melt, the formation of crystal structures causes substantial volume shrinkage, generating internal stress and causing warping of the printed parts.

[0007] (2) PLA material is modified by blending with other materials such as high heat resistance.

[0008] Combining PLA material with other high-T g Alternatively, highly crystalline materials can be blended and modified to prepare blended alloy materials. The improvement in heat resistance of this technique generally depends on the amount of high-heat-resistant components added; too low a concentration results in little improvement in heat resistance, while too high a concentration leads to significant reduction in interlayer adhesion due to the multiphase system. Simultaneously, high T... g The excessive introduction of highly crystalline materials can also reduce the material's resistance to warping.

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

[0010] T g It is the critical temperature at which polymer molecular chain segments possess the ability to move: T g Below a certain temperature, polymer molecular chains are in a "frozen" state and lack the ability to move; T g Above certain temperatures, polymer molecular chains "thaw," gaining the ability to move. Polymer crystallization, a process of ordered molecular chain arrangement, requires the chain segments to possess mobility; therefore, at temperatures above T... g Temperatures above a certain level represent the objective temperature conditions for polymer crystallization. One technical approach to improving the heat resistance of PLA printed parts is to subject the printed parts to a T-temperature test after printing. g Annealing heat treatment above a certain temperature works by heating the PLA printed parts to a temperature of T. g The above process enables PLA molecular chains to move, crystallize, and increase the crystallinity of the printed parts, thereby improving heat resistance. This is called the "annealing crystallization process." However, in the annealing crystallization process, the temperature is limited to T... gAs mentioned above, the molecular chain segments gain mobility, and during the crystallization process, the printed parts also carry the risk of deformation. Moreover, adding an 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, 3D printing filament, and 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 properties.

[0012] The first aspect of this specification provides a 3D printing material based on a three-phase system, comprising a first crystalline polymer, a second crystalline polymer, and a third-phase polymer; the second crystalline polymer comprises a micro- to nanoscale 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; when the third-phase polymer comprises a crystalline polymer, the melting point of the crystalline polymer is lower than that of the second crystalline polymer; when the third-phase polymer comprises an amorphous polymer, the glass transition temperature of the amorphous polymer is lower than that of the second crystalline polymer. The term "micro- to nanoscale fiber structure" as used above means that the diameter of the fiber dispersed phase is micro- to nanoscale, typically ranging from tens of nanometers, hundreds of nanometers, a few micrometers to tens of micrometers; the micro- to nanoscale fiber dispersed phase, with its high aspect ratio, high specific surface area, and excellent dispersion, enables it to form an entangled microfiber network structure at a relatively low fiber content, thereby exhibiting excellent reinforcement effects.

[0013] In the three-phase 3D printing material provided in this specification, the first crystalline polymer is the continuous matrix phase, the second crystalline polymer is the fiber-dispersed phase, and the third polymer is the auxiliary fiber-forming phase. In this 3D printing material, the second crystalline polymer forms a continuously distributed fiber-dispersed phase within the continuous matrix phase. The high specific surface area and high crystallinity of the fiber-dispersed phase can improve the crystallinity of the continuous matrix phase during 3D printing through heterogeneous nucleation, thereby improving the heat resistance of 3D printed parts based on the continuous matrix phase as the main component. Simultaneously, the fiber-dispersed phase also provides skeletal support to the continuous matrix phase, enabling the 3D printed parts based on the continuous matrix phase as the main component to possess excellent anti-warping properties. Given that the 3D printing material contains a first crystalline polymer and a second crystalline polymer, this specification further introduces a third-phase polymer into the 3D printing material. By utilizing the third polymer, the first crystalline polymer, and the second crystalline polymer to form a three-phase system, the content of fiber structures with high aspect ratios in the fiber dispersed phase of the 3D printing material can be effectively increased. With the increase in the content of fiber structures with high aspect ratios, the heat resistance of the 3D printing material can be further improved, thus enabling the three-phase system-based 3D printing material provided in this specification to possess both excellent heat resistance and anti-warping properties. When using the above-mentioned 3D printing material for 3D printing, a temperature lower than the melting point of the second crystalline polymer but higher than the melting point of the first crystalline polymer is selected as the printing temperature. This ensures that the first crystalline polymer melts at the printing temperature, while the morphology of the fiber dispersed phase formed by the second crystalline polymer remains unaffected. The fiber dispersed phase can preserve its micro- to nano-scale fiber structure without damage to its crystalline structure, ensuring that the fiber dispersed phase maintains its 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, wherein 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.

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

[0016] In some embodiments, the third-phase polymer includes a crystalline polymer having a melting point lower than that of the first crystalline polymer.

[0017] In some embodiments, the third-phase polymer comprises an amorphous polymer having a glass transition temperature lower than that of the first crystalline polymer.

[0018] In some embodiments, the melting point of the second crystalline polymer is 30°C or more 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 not less than 50°C.

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

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

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

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

[0026] The second aspect of this 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 using an in-situ fiber-forming technique, such that the second crystalline polymer forms a fibrous structure within the first crystalline polymer. Obtaining the above-mentioned 3D printing material using the in-situ fiber-forming technique enables the distribution of the fibrous structure formed by the second crystalline polymer within the continuous matrix phase formed by the first crystalline polymer in the 3D printing material to achieve relatively good uniformity.

[0027] The second aspect of this specification provides a 3D printing filament prepared from a three-phase-based 3D printing material as described above.

[0028] In some embodiments, the process includes extruding 3D printing material using a single screw to form filament; wherein the highest value of the extrusion temperature range 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, 3D printing filaments can be obtained during the preparation of 3D printing filaments without damaging the micro-nano-scale fiber structure of the 3D printing material.

[0029] The second aspect of this specification provides the application of the three-phase-based 3D printing materials or the 3D printing filaments described above in 3D printing technology. These applications include, but are not limited to, FFF printing.

[0030] In some embodiments, a temperature below the melting point of the second crystalline polymer and above the melting point of the first crystalline polymer is used as the printing temperature for 3D printing. This allows the micro-nanoscale fiber structure formed by the second crystalline polymer to be maintained during the 3D printing process, ensuring the crystalline structure remains intact and is directly introduced into the printed part. This prevents the printed part from warping due to internal stress caused by the second crystalline polymer in the 3D printing material.

[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. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this specification, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

[0034] Figure 2 shows a schematic diagram of an anti-warping printed model used in some embodiments according to this specification;

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

[0036] Figure 4 shows the warpage test results of the 3D printed part in Example 1 of this specification;

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

[0038] Figure 6 shows the warpage test results of the 3D printed part in Example 2 of this specification;

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

[0040] Figure 8 shows the warpage test results of the 3D printed part in Example 3 of this specification;

[0041] Figure 9 is a micrograph of the fiber structure in the 3D printing filament of Example 4 of this specification;

[0042] Figure 10 shows the warpage test results of the 3D printed part in Example 4 of this specification;

[0043] Figure 11 is a micrograph of the fiber structure in the 3D printing filament of Example 5 of this specification;

[0044] Figure 12 shows the warpage test results of the 3D printed part in Example 5 of this specification;

[0045] Figure 13 is a micrograph of the fiber structure in the 3D printing filament of Example 6 of this specification;

[0046] Figure 14 shows the warpage test results of the 3D printed part in Example 6 of this specification;

[0047] Figure 15 is a micrograph of the fiber structure in the 3D printing filament of Example 7 of this specification;

[0048] Figure 16 is a micrograph of the fiber structure in the 3D printing filament of Example 7 of this specification;

[0049] Figure 17 shows the warpage test results of the 3D printed part of Comparative Example 1 in this specification;

[0050] Figure 18 shows the warpage test results of the 3D printed part of Comparative Example 2 in this specification;

[0051] Figure 19 is a micrograph of the fiber structure in the 3D printed filament of Comparative Example 3 of this specification.

[0052] Figure 20 shows the warpage test results of the 3D printed part of Comparative Example 3 in this specification;

[0053] Figure 21 is a micrograph of the fiber structure in the 3D printed filament of Comparative Example 4 of this specification.

[0054] Figure 22 shows the warpage test results of the 3D printed part of Comparative Example 4 in this specification; Detailed Implementation

[0055] The following description provides specific application scenarios and requirements for this specification, intended to enable those skilled in the art to make and use the contents of this specification. Various partial modifications to the disclosed embodiments will be apparent to those skilled in the art, and the general principles defined herein can 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 rather to the widest scope consistent with the claims.

[0056] To facilitate understanding of this specification, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this specification are shown 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. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure of this specification.

[0057] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not restrictive. For example, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” used herein may also include the plural forms. When used in this specification, the terms “comprising,” “including,” and / or “containing” mean that the associated integers, steps, operations, elements, and / or components are present, but do not exclude the presence 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 to the system / method.

[0058] In this 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 can include any combination of A, B, and C, or any combination of A, B, and C, as well as other possible content / elements. The arbitrary combination of A, B, and C can be A, B, C, AB, AC, BC, or ABC.

[0059] Considering the following description, these and other features of this specification, as well as the operation and function of related structural elements, and the economy of component assembly and manufacture, can be significantly improved. This description also includes all figures and text in the accompanying drawings, all of which form part of this specification. However, it should be clearly understood that the drawings are for illustrative and descriptive purposes only and are not intended to limit the scope of this specification. It should also be understood that the drawings are not drawn to scale. Furthermore, for ease of description, the terms that may appear in this specification are explained below.

[0060] In-situ fiber formation technology refers to a processing method for fiber-reinforced materials where multiple incompatible polymers are blended, and then an external force field is applied to subject the dispersed phase in the two-phase system to tensile or shear forces, causing it to orient along the direction of the force and fibrousize. This results in the formation of oriented micro- to nano-scale fibers within the continuous phase. This type of fiber-reinforced composite material, which uses a special processing technique to form the fibrous phase "in situ," is figuratively called "in-situ micro fiber formation composites" (iMFC), as illustrated in Figure 1.

[0061] A crystalline polymer is a polymer in which at least one component is crystallizable and has a sufficient sequence length to form crystals. In a crystalline polymer, regions with regularly arranged molecules are called crystalline regions, and regions with disordered molecular arrangement are called amorphous regions. The percentage of crystalline regions is called the degree of crystallinity. For ease of description, this specification uses the term "crystalline polymer" to refer to a crystalline polymer that simultaneously possesses crystalline and amorphous regions. It should be noted that both the first and second crystalline polymers in this specification are crystalline polymers, but they contain different types of crystals. 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 in the third phase polymer are all different.

[0062] Amorphous polymers are polymers whose molecules are randomly arranged and lack a clear crystalline structure. Amorphous polymers do not have a fixed melting point; their melting process occurs over a temperature range rather than a fixed point. For amorphous polymers, the "glass transition temperature" is more commonly used, referring to the temperature at which molecules transition from a frozen state to a state of motion.

[0063] According to a first aspect of this specification, a 3D printing material based on a three-phase system is provided, comprising a first crystalline polymer, a second crystalline polymer, and a third-phase polymer; the second crystalline polymer comprises a micro- to 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; when the third-phase polymer comprises a crystalline polymer, the melting point of the crystalline polymer is lower than that of the second crystalline polymer; when the third-phase polymer comprises an amorphous polymer, the glass transition temperature of the amorphous polymer is lower than that of the second crystalline polymer. The term "micro- to nano-scale fiber structure" as used above means that the diameter of the fiber dispersed phase is micro- to nano-scale, typically ranging from tens of nanometers, hundreds of nanometers, a few micrometers to tens of micrometers; the micro- to nano-scale fiber dispersed phase, with its high aspect ratio, high specific surface area, and excellent dispersion, enables it to form an entangled microfiber network structure at a relatively low fiber content, thereby exhibiting excellent reinforcing effects.

[0064] In the three-phase 3D printing material provided in this specification, the first crystalline polymer is the continuous matrix phase, the second crystalline polymer is the fiber-dispersed phase, and the third polymer is the auxiliary fiber-forming phase. In this 3D printing material, the second crystalline polymer forms a continuously distributed fiber-dispersed phase within the continuous matrix phase. The high specific surface area and high crystallinity of the fiber-dispersed phase can improve the crystallinity of the continuous matrix phase during 3D printing through heterogeneous nucleation, thereby improving the heat resistance of 3D printed parts based on the continuous matrix phase as the main component. Simultaneously, the fiber-dispersed phase also provides skeletal support to the continuous matrix phase, enabling the 3D printed parts based on the continuous matrix phase as the main component to possess excellent anti-warping properties. Given that the 3D printing material contains a first crystalline polymer and a second crystalline polymer, this specification further introduces a third-phase polymer into the 3D printing material. By utilizing the third polymer, the first crystalline polymer, and the second crystalline polymer to form a three-phase system, the content of fiber structures with high aspect ratios in the fiber dispersed phase of the 3D printing material can be effectively increased. With the increase in the content of fiber structures with high aspect ratios, the heat resistance of the 3D printing material can be further improved, thus enabling the three-phase system-based 3D printing material provided in this specification to possess both excellent heat resistance and anti-warping properties. When using the above-mentioned 3D printing material for 3D printing, a temperature lower than the melting point of the second crystalline polymer but higher than the melting point of the first crystalline polymer is selected as the printing temperature. This ensures that the first crystalline polymer melts at the printing temperature, while the morphology of the fiber dispersed phase formed by the second crystalline polymer remains unaffected. The fiber dispersed phase can preserve its micro- to nano-scale fiber structure without damage to its crystalline structure, ensuring that the fiber dispersed phase maintains its 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, wherein 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.

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

[0067] In some embodiments, the third-phase polymer includes a crystalline polymer having a melting point lower than that of the first crystalline polymer.

[0068] In some embodiments, the third-phase polymer comprises an amorphous polymer having a glass transition temperature lower than that of the first crystalline polymer.

[0069] In some embodiments, the melting point of the second crystalline polymer is 30°C or more 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 not 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 affects the enhancement of the material's processing performance and heat resistance. Controlling the mass percentage of the second crystalline polymer within this range allows for more full utilization of its heterogeneous nucleation effect, significantly improving the crystallinity of the 3D printed part. Simultaneously, it helps the first crystalline polymer maintain good printing performance and promotes the uniform distribution of the fiber dispersed phase in the continuous matrix phase. If the content of the second crystalline polymer is below the above range, the crystallinity of the 3D printed part will decrease; if the content is above 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 prone to agglomeration. 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%, etc., but not limited to the listed values; other unlisted values ​​within this range also apply.

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

[0073] In other embodiments, the mass percentage of the second crystalline polymer in the 3D printing material can 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; other unlisted values ​​within this range are also applicable.

[0075] In some embodiments, the first crystalline polymer is polylactic acid (PLA). As one of the most commonly used materials in FFF printing, a mainstream technology in current extrusion 3D printing, PLA has the best fit for the implementation of the embodiments described above, and can solve the long-standing technical pain points of the high heat resistance technology route for 3D printing with PLA materials.

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

[0079] According to a second aspect of this 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 using an in-situ fiber-forming technique, such that the second crystalline polymer forms a fibrous structure within the first crystalline polymer. Obtaining the 3D printing material using the in-situ fiber-forming technique enables the distribution of the fibrous structure formed by the second crystalline polymer within the continuous matrix phase formed by the first crystalline polymer to achieve relatively good uniformity.

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

[0081] In some embodiments, the process includes extruding 3D printing material using a single screw to form filament; wherein the highest value of the extrusion temperature range 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, 3D printing filaments can be obtained during the preparation of 3D printing filaments without damaging the micro-nano-scale fiber structure of the 3D printing material.

[0082] According to the fourth aspect of this specification, the application of the three-phase-based 3D printing materials or the 3D printing filaments described above in 3D printing technology is provided. The applications herein include, but are not limited to, FFF printing.

[0083] In some embodiments, a temperature below the melting point of the second crystalline polymer and above the melting point of the first crystalline polymer is used as the printing temperature for 3D printing. This allows the micro-nanoscale fiber structure formed by the second crystalline polymer to be maintained during the 3D printing process, ensuring the crystalline structure remains intact and is directly introduced into the printed part. This prevents the printed part from warping due to internal stress caused by the second crystalline polymer in the 3D printing material.

[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 their preparation methods described above are designed based on the material defects present in 3D printing. Using existing printing materials (e.g., polylactic acid) as the first crystalline polymer (continuous matrix phase), a high-melting-point second crystalline polymer (fiber-dispersed phase) and a third-phase polymer (fiber-forming auxiliary phase) are introduced to prepare a three-phase 3D printing material. The resulting 3D printing material contains micro-nano-scale fiber structures formed by the second crystalline polymer. Under the influence of the third-phase polymer, these fiber structures exhibit better fiber-forming quality, with a high content of high aspect ratio fibers. The high aspect ratio fibers in the second crystalline polymer fiber structures have a higher specific surface area, enabling them to better exert the crystalline heterogeneous nucleation effect, thereby more effectively promoting the crystallinity of the first crystalline polymer. Simultaneously, the micro-nano-scale fiber structures can serve as reinforcing phases. The high aspect ratio fibers are more conducive to forming microfiber mesh structures in the first crystalline polymer even with a low content of the second crystalline polymer, thus providing excellent reinforcement and improving the anti-warping properties of the printed parts. In summary, the high crystallinity and high heat resistance of the micro-nano fiber structure enable the 3D printing material provided in this specification to have both good heat resistance and excellent anti-warping properties.

[0086] During the 3D printing process using the aforementioned 3D printing material, printing is performed below the melting point temperature of the second crystalline polymer. This not only preserves the micro-nano-scale fiber structure of the second crystalline polymer but also ensures that the crystalline structure of the second crystalline polymer is not damaged and can be directly introduced into the printed part without causing warping behavior of the printed part due to the internal stress of the second crystalline polymer.

[0087] The features and performance of this specification will be further described in detail below with reference to embodiments and comparative examples.

[0088] The first crystalline polymer within the wire was removed using an organic solvent, and the second crystalline polymer was extracted. Microscopic observation was performed, and the lengths of over 100 fibers were measured and averaged to obtain the number-average length LM. The diameters of over 10 fibers were measured and averaged to obtain the diameter D. The fiber aspect ratio was defined as: [Equation omitted for brevity]. M Divide by the diameter D, that is, calculate using the following formula:

[0089] The anti-warping printing test methods used in the embodiments and comparative examples of this specification are as follows:

[0090] Under a preset target external environment, 3D printing material of the target size is printed onto a target substrate using a target process flow to form a cuboid target part of the target size (L×W×H). Figure 2 shows a schematic diagram of the target printing model used in some embodiments of this specification, wherein the side of the target part that contacts the target substrate is the bottom surface, with a length of L, a width of W, and a height of H; after the cuboid part cools, the height of the four corners of the bottom surface of the cuboid part detaching from the target substrate (that is, the distance between the four corners and the highest point of the target substrate) is measured, and the average value h is calculated; then the warp value of the 3D material is defined as: the h value divided by the height H of the target part, i.e., calculated using the following formula:

[0091] Clearly, given a fixed L, W, and H, the smaller the average height h of the four corners of the bottom surface of the cuboid after cooling, the smaller the deformation and warpage of the part during cooling. In this specification, the warpage resistance of the 3D printing material can be measured by the deformation generated during the printing process. The less warpage the printed 3D product, the better the warpage resistance of the 3D printing material.

[0092] It is understandable that for the same material, the cooling rate and the degree of uniformity of cooling will be different under different standard sizes and different external cooling environments, and therefore its warpage will also be different.

[0093] According to some embodiments of this application, the preset target external environment may include: the printing material is PLA filament with a diameter of 1.75mm ± 0.05mm, the printing nozzle diameter is 0.4mm, the slicing parameters during printing are a line width of 0.4mm, a layer height of 0.2mm, a shell number of 13, and a printing speed of 100mm / s. Furthermore, the printing temperature in this embodiment is appropriately matched according to the material type and extrusion characteristics; for example, the printing temperature for PLA material is 190–230℃, and the substrate temperature is 30–60℃.

[0094] For example, if the target part (printed part) is 150mm long and 20mm high, and the average warpage height h at the four corners after cooling is 1mm, then the Warp warpage rate is calculated as 5%. If the model warps severely and the height H does not reach 20mm due to printing failure, then the actual printable height is used for calculation. For example, if the target part (printed part) is 150mm long and 10mm high, and the average warpage height h at the four corners after cooling is 1mm, then the Warp warpage rate is calculated as 10%.

[0095] Example 1

[0096] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0097] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0098] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃), with polyphenylene sulfide (PPS) as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The temperature is 285℃), with polypropylene (PP) as the third-phase polymer (auxiliary fiber-forming phase, melting point T). m3 (165℃).

[0099] In this embodiment, the amounts of PLA, PPS, and PP are satisfied. 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 mixing PLA, PPS, and PP in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–300°C. The extruded material is drawn into a strip, cooled and shaped in a room-temperature water bath, and then pelletized using a pelletizer to obtain the 3D printing material.

[0100] 2) The prepared 3D printing material is processed into 3D printing filament.

[0101] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0102] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 3. The fiber aspect ratio is 121.3, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0103] 3) Perform FFF printing test on the 3D printing filament.

[0104] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 4. The cuboid has a length L = 150 mm, a width W = 9.6 mm, and a height H = 20 mm. As shown in Figure 4, the warpage rate of the printed part was 0.47%, and the entire printed part showed no warpage, demonstrating excellent warpage resistance.

[0105] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 166.5℃, which shows good heat resistance.

[0106] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0107] Example 2

[0108] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0109] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0110] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃), with polyphenylene sulfide (PPS) as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The temperature is 285℃, with polyethylene (PE) as the third-phase polymer (auxiliary fiber-forming phase, melting point T). m3 (130℃).

[0111] In this embodiment, the amounts of PLA, PPS, and PE are satisfied. In the 3D printing material composed of these three components, the mass content of the second crystalline polymer PPS is 20%, and the mass content of the third phase polymer PE is 12%. After mixing PLA, PPS, and PE in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–300°C. The extruded material is then drawn into a strip, cooled and shaped in a room-temperature water bath, and pelletized using a pelletizer to obtain the 3D printing material.

[0112] 2) The prepared 3D printing material is processed into 3D printing filament.

[0113] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0114] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 5. The fiber aspect ratio is 115.0, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0115] 3) Perform FFF printing test on the 3D printing filament.

[0116] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 6: length L = 150mm, width W = 9.6mm, height H = 20mm. As shown in Figure 6, the warpage rate of the printed part was 0.52%, and the entire printed part showed no warpage, exhibiting excellent warpage resistance.

[0117] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 163.4℃, which shows good heat resistance.

[0118] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0119] Example 3

[0120] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0121] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0122] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃), with polyphenylene sulfide (PPS) as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The glass transition temperature is 285℃, with polyethylene terephthalate-1,4-cyclohexanediethanol ester (PETG) as the third-phase polymer (auxiliary fiber-forming phase, glass transition temperature T). g3 (78℃).

[0123] In this embodiment, the amounts of PLA, PPS, and PETG are satisfied. In the 3D printing material composed of these three components, the mass content of the second crystalline polymer PPS is 10%, and the mass content of the third phase polymer PETG is 7%. After mixing PLA, PPS, and PETG in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–300°C. The extruded material is drawn into a strip, cooled and shaped in a room-temperature water bath, and then pelletized using a pelletizer to obtain the 3D printing material.

[0124] 2) The prepared 3D printing material is processed into 3D printing filament.

[0125] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0126] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 7. The fiber aspect ratio is 96.4, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0127] 3) Perform FFF printing test on the 3D printing filament.

[0128] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 8: length L = 150 mm, width W = 9.6 mm, height H = 20 mm. As shown in Figure 8, the warpage rate of the printed part was 0.65%, and the entire printed part showed no warpage, exhibiting excellent warpage resistance.

[0129] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 157.0℃, which shows good heat resistance.

[0130] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0131] Example 4

[0132] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0133] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0134] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃), with polyphenylene sulfide (PPS) as the second crystalline polymer (fiber dispersed phase, melting point T).m2 The glass transition temperature is 285℃, with polystyrene as the third-phase polymer (auxiliary fiber-forming phase, glass transition temperature T). g3 (100℃).

[0135] In this embodiment, the amounts of PLA, PPS, and PS are satisfied. 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 mixing PLA, PPS, and PS in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–300°C. The extruded material is drawn and shaped, cooled and shaped in a room-temperature water bath, and then pelletized using a pelletizer to obtain the 3D printing material.

[0136] 2) The prepared 3D printing material is processed into 3D printing filament.

[0137] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0138] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 9. The fiber aspect ratio is 90.2, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0139] 3) Perform FFF printing test on the 3D printing filament.

[0140] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 10: length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. As shown in Figure 10, the warpage rate of the printed part was 0.71%, and the entire printed part showed no warpage, demonstrating excellent warpage resistance.

[0141] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 150.1℃, which shows good heat resistance.

[0142] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0143] Example 5

[0144] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0145] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0146] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃, with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The glass transition temperature is 310℃, with polystyrene as the third-phase polymer (auxiliary fiber-forming phase, glass transition temperature T). g3 (100℃).

[0147] In this embodiment, the amounts of PLA, PA6T, and PS are satisfied. 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 mixing PLA, PA6T, and PS in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–330°C. The extruded material is drawn and shaped, cooled and shaped in a room-temperature water bath, and then pelletized using a pelletizer to obtain the 3D printing material.

[0148] 2) The prepared 3D printing material is processed into 3D printing filament.

[0149] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0150] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 11. The fiber aspect ratio is 87.6, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0151] 3) Perform FFF printing test on the 3D printing filament.

[0152] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 12: length L = 150mm, width W = 9.6mm, and height H = 20mm. As shown in Figure 12, the warpage rate of the printed part was 0.85%, and the entire printed part showed no warpage, demonstrating excellent warpage resistance.

[0153] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 140.6℃, which shows good heat resistance.

[0154] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0155] Example 6

[0156] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0157] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0158] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃, with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The glass transition temperature is 310℃, with polyethylene terephthalate-1,4-cyclohexanediethanol ester (PETG) as the third-phase polymer (auxiliary fiber-forming phase, glass transition temperature T). g3 (78℃).

[0159] In this embodiment, the amounts of PLA, PA6T, and PETG are satisfied. In the 3D printing material composed of these three components, the mass content of the second crystalline polymer PA6T is 12%, and the mass content of the third phase polymer PETG is 20%. After mixing PLA, PA6T, and PETG in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–330°C. The extruded material is then drawn into a strip, cooled and shaped in a room-temperature water bath, and pelletized using a pelletizer to obtain the 3D printing material.

[0160] 2) The prepared 3D printing material is processed into 3D printing filament.

[0161] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0162] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 13. The fiber aspect ratio is 92.9, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0163] 3) Perform FFF printing test on the 3D printing filament.

[0164] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 14: length L = 150 mm, width W = 9.6 mm, and height H = 20 mm. As shown in Figure 14, the warpage rate of the printed part was 0.68%, and the entire printed part showed no warpage, demonstrating excellent warpage resistance.

[0165] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 144.3℃, which shows good heat resistance.

[0166] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0167] Example 7

[0168] This embodiment provides an FFF printing method, which specifically includes the following steps:

[0169] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0170] Polylactic acid (PLA) is used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃, with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The temperature is 310℃, with polyethylene (PE) as the third phase polymer (auxiliary fiber-forming phase, melting point T). m3 (130℃).

[0171] In this embodiment, the amounts of PLA, PA6T, and PE are satisfied. In the 3D printing material composed of these three components, the mass content of the second crystalline polymer PA6T is 30%, and the mass content of the third phase polymer PE is 17%. After mixing PLA, PA6T, and PE in the specified proportions, the mixture is compounded using a twin-screw extrusion process at a processing temperature of 220–330°C. The extruded material is then drawn into a strip, cooled and shaped in a room-temperature water bath, and pelletized using a pelletizer to obtain the 3D printing material.

[0172] 2) The prepared 3D printing material is processed into 3D printing filament.

[0173] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0174] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 15. The fiber aspect ratio is 106.7, indicating that the second crystalline polymer has good fiber formation quality in the 3D printing filament in this embodiment.

[0175] 3) Perform FFF printing test on the 3D printing filament.

[0176] The FFF-printed part was subjected to a warpage resistance test at a temperature of 210℃, resulting in the cuboid shown in Figure 16: length L = 150mm, width W = 9.6mm, height H = 20mm. As shown in Figure 16, the warpage rate of the printed part was 0.60%, and the entire printed part showed no warpage, exhibiting excellent warpage resistance.

[0177] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 159.8℃, which shows good heat resistance.

[0178] Therefore, the 3D printing material prepared in this embodiment has both excellent anti-warping properties and heat resistance of the printed parts.

[0179] Comparative Example 1

[0180] This comparative example uses the same PLA material as in Example 1 to prepare 3D printing material.

[0181] PLA raw material particles were used to prepare PLA wire rods via single-screw extrusion molding. The single-screw extrusion molding process used in this comparative example employed the same process conditions as that in Example 1. The resulting PLA wire rods contained neither a second crystalline polymer nor a third-phase polymer.

[0182] The PLA filament prepared in this comparative example was used for FFF printing tests, and the process conditions were consistent with those involved in the FFF printing test in Example 1. Figure 17 shows a photograph of the finished product after printing. As shown in Figure 17, the printed part is free of warping and exhibits excellent anti-warping properties.

[0183] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was found to be 61.7℃, indicating that the printed parts prepared in this comparative example have low heat resistance.

[0184] Therefore, it can be seen that compared with the 3D printing materials prepared in Examples 1 to 7, the PLA printing material provided in Comparative Example 1 has significantly poorer heat resistance, and it cannot enable the printed parts made using it to have both excellent anti-warping properties and heat resistance.

[0185] Comparative Example 2

[0186] This comparative example uses the same PLA material as in Example 1, with the addition of an organic hydrazine crystallizing nucleating agent at a weight ratio of 1% relative to the polylactic acid material. The 3D printing filament is prepared using the same twin-screw compounding process and single-screw extrusion filament processing process as in Example 1.

[0187] The 3D printing filament prepared in this comparative example was used for FFF printing tests, and the process conditions were consistent with those involved in the FFF printing test in Example 1. Figure 18 shows a photograph of the printed product. As shown in Figure 18, the printed part exhibited significant warping, with a warping rate of 17.3%, which is worse than that of Examples 1-7, demonstrating poor warping resistance.

[0188] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was found to be 145.3℃.

[0189] Therefore, 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 anti-warping properties and heat resistance.

[0190] Comparative Example 3

[0191] This comparative example specifically includes the following steps:

[0192] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0193] Similar to Examples 1-4, polylactic acid (PLA) was used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃), with polyphenylene sulfide (PPS) as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The temperature is 285℃, and the PLA wire produced in this way does not contain a third-phase polymer.

[0194] In this embodiment, the amounts of PLA and PPS are satisfied, and the mass content of the second crystalline polymer PPS in the 3D printing material composed of the two is 25%. After PLA and PPS are mixed in proportion, they are compounded using a twin-screw extrusion process at a processing temperature of 220-300°C. The extruded material is drawn and shaped by cooling in a room-temperature water bath, and then pelletized by a pelletizer to obtain the 3D printing material.

[0195] 2) The prepared 3D printing material is processed into 3D printing filament.

[0196] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0197] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 19. The fiber aspect ratio is 36.4, indicating that the fiber formation quality of the second crystalline polymer in the 3D printing filament is poor in this embodiment.

[0198] 3) Perform FFF printing test on the 3D printing filament.

[0199] The FFF-printed part was subjected to a warpage resistance test at 210℃, resulting in the cuboid shown in Figure 20: length L = 150mm, width W = 9.6mm, height H = 20mm. As shown in Figure 20, the warpage rate of the printed part was 8.5%, indicating poor warpage resistance.

[0200] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 86.1℃, which is poor heat resistance.

[0201] Therefore, compared with the 3D printing materials prepared by the two-phase polymer in Examples 1-4, the 3D printing materials provided by the two-phase polymer in Comparative Example 3 have significantly poorer anti-warping and heat resistance properties, and cannot enable the printed parts made by it to have both excellent anti-warping and heat resistance properties.

[0202] Comparative Example 4

[0203] This comparative example specifically includes the following steps:

[0204] 1) Preparation of in-situ fiber-forming 3D printing materials.

[0205] Similar to Examples 5-7, polylactic acid (PLA) was used as the first crystalline polymer (continuous matrix phase, melting point T). m1 The temperature is 170℃, with poly(hexamethylene terephthalamide) PA6T as the second crystalline polymer (fiber dispersed phase, melting point T). m2 The temperature is 310℃, and the PLA wire produced in this way does not contain a third-phase polymer.

[0206] In this embodiment, the amounts of PLA and PA6T are satisfied, and the mass content of the second crystalline polymer PA6T in the 3D printing material composed of the two is 30%. After PLA and PA6T are mixed in proportion, they are compounded using a twin-screw extrusion process at a processing temperature of 220-330°C. The extruded material is drawn and shaped by cooling in a room-temperature water bath, and then pelletized by a pelletizer to obtain the 3D printing material.

[0207] 2) The prepared 3D printing material is processed into 3D printing filament.

[0208] The specific operation is as follows: the above-mentioned 3D printing material is extruded by a single screw at a temperature of 160-240℃ to prepare 3D printing filament.

[0209] The fiber structure of the obtained 3D printing filament was observed under a microscope. The micro-nano fiber structure is shown in Figure 21. The fiber aspect ratio is 32.1, indicating that the fiber formation quality of the second crystalline polymer in the 3D printing filament is poor in this embodiment.

[0210] 3) Perform FFF printing test on the 3D printing filament.

[0211] The FFF-printed parts were subjected to a warpage resistance test at 210℃, resulting in the part shown in Figure 22. Due to severe warpage, it was impossible to print a height H = 20mm. Therefore, the final cuboid has the following dimensions: length L = 150mm, width W = 9.6mm, and height H = 10mm. As shown in Figure 22, the warpage rate of the printed part was 24.3%, indicating poor warpage resistance.

[0212] Meanwhile, the Vicat softening temperature (VST) of the printed parts was tested using GB / T 1633-2000 thermoplastics, A120 method, with a force of 10N and a heating rate of 120℃ / h. The Vicat softening temperature of the printed parts was measured to be 77.7℃, which is relatively low.

[0213] Therefore, compared with the 3D printing materials prepared by the two-phase polymer in Examples 5-7, which introduce a third-phase polymer, the 3D printing materials provided by the two-phase polymer in Comparative Example 3 have significantly poorer anti-warping and heat resistance properties, and cannot enable the printed parts made by using it to have both excellent anti-warping and heat resistance properties.

[0214] In summary, after reading this detailed disclosure, those skilled in the art will understand that the foregoing detailed disclosure is presented by way of example only and is not restrictive. Although not explicitly stated herein, those skilled in the art will understand 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 made by this specification and are within the spirit and scope of the exemplary embodiments described herein.

[0215] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.

[0216] Furthermore, certain terms in this specification have been used to describe embodiments of this specification. For example, "an embodiment," "an embodiment," and / or "some embodiments" mean that a particular feature, structure, or characteristic described in connection with that embodiment may be included in at least one embodiment of this specification. Therefore, it is to be emphasized and understood that two or more references to "an embodiment" or "an embodiment" or "alternative embodiment" in various parts of this specification do not necessarily refer to the same embodiment. Moreover, specific features, structures, or characteristics may be suitably combined in one or more embodiments of this specification.

[0217] It should be understood that in the foregoing description of the embodiments of this specification, for the purpose of simplifying the description and to aid in understanding a feature, various features are sometimes combined in a single embodiment, drawing, or description thereof. Alternatively, various features may be distributed across multiple embodiments of this specification. However, this does not mean that the combination of these features is necessary, and those skilled in the art, upon reading this specification, may extract some features as individual embodiments for understanding. That is, the embodiments in this specification can also be understood as an integration of multiple sub-embodiments. It is also valid when each sub-embodiment contains fewer than all the features of a single foregoing disclosed embodiment.

Claims

1. A 3D printing material based on a three-phase system, characterized in that, include: First crystalline polymer; The second crystalline polymer includes a micro- to nano-scale fibrous structure, and the melting point of the second crystalline polymer is higher than that of the first crystalline polymer. as well as The third phase polymer includes at least one of a crystalline polymer or an amorphous polymer; wherein the melting point of the crystalline polymer is lower than that of the second crystalline polymer; and the glass transition temperature of the amorphous polymer is lower than that 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 amorphous 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 that of the first crystalline polymer; The glass transition temperature of the third-phase amorphous 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 more than 30°C higher than that of the first crystalline polymer.

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 second crystalline polymer constitutes 3% to 40% of the mass of the 3D printing material.

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

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 crystalline polyester material, crystalline polyamide material, crystalline polyether material, crystalline polyolefin material, or crystalline fluoropolymer.

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 a 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, etc.

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

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

14. The application of the 3D printing material based on a three-phase system as described in any one of claims 1 to 10 or the 3D printing filament as described in claim 13 in 3D printing technology.

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

16. The application 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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