3D printing methods and 3D printed bodies
By using a dual-curing resin photocuring and stretching combined with thermosetting method, the problem of time-consuming and costly large 3D printed parts has been solved, and efficient manufacturing of 3D printed parts that are not limited by machine size has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- AMPLIFI TECH (XIAMEN) LTD
- Filing Date
- 2022-10-27
- Publication Date
- 2026-06-30
AI Technical Summary
Existing 3D printing technology is costly and time-consuming when printing large parts, is limited by the size of the worktable, and fails to effectively utilize the characteristics of dual-curing resins.
Using dual-curing resin, an intermediate is formed by photocuring and then stretched, combined with thermocuring for shaping. The stretching step applies stress to the intermediate to achieve the target size and performs pre-compensation to form a large-volume 3D printed body.
It improves 3D printing efficiency, reduces equipment costs, and allows the printed parts to be manufactured without being limited by the table size in the XY direction of the machine, thus enabling efficient manufacturing of large parts.
Smart Images
Figure CN117984550B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a 3D printing method and a 3D printed object. Background Technology
[0002] 3D printing refers to the process of printing any three-dimensional object. It is primarily an additive process, layering raw materials under computer control. The content of 3D printing can originate from three-dimensional models or other electronic data, and the printed three-dimensional objects can possess arbitrary shapes and geometric features.
[0003] With the development of technology, many industries have begun to apply 3D printing technology, such as architecture, industrial design, automobiles, clothing, and food, creating many groundbreaking products.
[0004] However, according to known 3D printing technology, printing larger 3D models requires a large XY area worktable. But the high cost of 3D printing equipment limits the area that can be printed in the XY direction. Furthermore, because 3D printing equipment has a limited printing speed in the Z direction, printing larger 3D models in the Z direction will consume a significant amount of time.
[0005] Specifically, patent CN110023056A discloses a method for manufacturing 3D objects, which first photocures a dual-curing resin to form an intermediate, then contacts the intermediate with a penetrating liquid, and finally thermocures the intermediate. However, the method in CN110023056A forms the final product shape in the photocured intermediate without stretching or pre-compensation. Similarly, patent US20160339627A discloses a method for manufacturing 3D objects using a photocurable resin to form an intermediate, which is then shaped to the desired size by the shrinkage of the substrate; however, it does not disclose the use of a dual-curing resin or the stretching of the intermediate. Therefore, the known technologies are extremely time-consuming and costly in printing large 3D molded objects, and there is room for further improvement. Summary of the Invention
[0006] The inventors have discovered that by selecting a dual-curing resin material, which possesses the characteristic of two curing cycles (photocuring + thermocuring), a stretching step is performed after UV-curing 3D printing, followed by thermocuring for shaping, to obtain a large-volume 3D printed body, thus improving known problems. Specifically, stretching can be performed in the Z direction to save printing time; and stretching can be performed in the X or Y direction to overcome the limitations of the 3D printer's worktable size.
[0007] To address the aforementioned problems, the 3D printing method of the present invention includes: a resin supply step of providing a dual-curing resin; a photocuring step of irradiating the dual-curing resin with UV light to perform 3D printing to form an intermediate having a specific lattice shape; a stretching step of applying stress to the intermediate in a stretching direction according to a stretching ratio of a desired size to stretch and form a stretched body; and a thermosetting step of heating the stretched body to perform thermosetting and shaping to form a 3D printed body; wherein, during the 3D printing, the dimensions of the intermediate in the non-stretching direction are pre-compensated based on the stretching ratio.
[0008] In this embodiment, the photocuring step and the stretching step are performed simultaneously.
[0009] In this embodiment, the photocuring step is performed with the cross section as the curing unit.
[0010] In one embodiment, during the stretching step, the stress is applied by contact stretching of the intermediate.
[0011] In this embodiment, the stress intensity during the stretching step is 0.1 to 0.5 N.
[0012] In one embodiment, the stress is applied at one end of the intermediate body along its length.
[0013] In this embodiment, the stress is applied more than twice.
[0014] In this embodiment, the stress is applied twice, and the location where the stress is applied for the first time is different from the location where the stress is applied for the second time.
[0015] In this embodiment, the stress is applied in a direction parallel to the cross section of the photocured material.
[0016] In this embodiment, the stress is applied in a direction perpendicular to the cross-section of the photocured material.
[0017] In one embodiment, a trimming step is included after the thermosetting step to remove a portion of the stretched body after the thermosetting step in order to form the 3D printed body.
[0018] To solve the above problems, the 3D printed body of the present invention is manufactured by the 3D printing method of the present invention.
[0019] This invention addresses the aforementioned problems and aims to provide a 3D printing method and a 3D printed object. The 3D printing method of this invention improves upon the limitations of 3D printing efficiency and size caused by the machine tool. Furthermore, the 3D printed object manufactured using this method is not limited by the XY dimensions of the 3D printing table, and the increased printing efficiency reduces manufacturing costs. Attached Figure Description
[0020] Figure 1 This is a flowchart of a 3D printing method according to an embodiment of the present invention;
[0021] Figure 2 This is a flowchart of a 3D printing method according to another embodiment of the present invention;
[0022] Figure 3 This is a schematic diagram of stretching the intermediate body;
[0023] Figure 4 This is a schematic diagram showing the application of stress to an intermediate body from different tensile directions to form a tensile body.
[0024] Figure 5 Photographs of 3D printed bodies from the Reference Example, Example 3, and Comparative Example.
[0025] [Attached image labels]
[0026] Steps S1 to S5
[0027] A intermediate
[0028] B, C stretching bodies
[0029] X, Y, Z directions Detailed Implementation
[0030] The following describes the implementation of the present invention through specific embodiments. Those skilled in the art can understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0031] Unless otherwise stated herein, the terms "or" as used in the specification and appended claims have the meanings of "and / or".
[0032] Unless otherwise stated herein, the term "A to B" as used in the specification and appended claims includes the meaning of "more than A and less than B". For example, the term "10 to 40% by weight" includes the meaning of "more than 10% by weight and less than 40% by weight".
[0033] 3D printing methods
[0034] The 3D printing method of this invention can be used to produce large-sized 3D printed shapes. Furthermore, the 3D printing method of this invention can improve the problems of poor efficiency and size limitations due to machine limitations in 3D printing.
[0035] The 3D printing method of this invention is as follows: Figure 1 As shown, the process includes a resin supply step S1, a light curing step S2, a stretching step S3, and a thermosetting step S4, and may also include a trimming step S5 if necessary. Each step will be explained below.
[0036] Resin supply step S1
[0037] The resin providing step S1 provides a dual-curing resin. The dual-curing resin used in this invention is a resin that can be cured by both light and heat. Specifically, the dual-curing resin can be molded and shaped through a dual curing process involving UV light irradiation and heating. Specific examples of dual-curing resins can be found in Chinese Patent CN110023056A, the entire contents of which are incorporated herein by reference. In the embodiments, the dual-curing resin can be selected from commercially available products and is not particularly limited. For example, dual-curing resins such as Carbon's EPU40, EPU41, and EPU44 can be used, and dual-curing resins with similar mechanical properties to the aforementioned dual-curing resins are also applicable and are not particularly limited.
[0038] Photocuring step S2
[0039] The photocuring step S2 involves irradiating the dual-curing resin with UV light to photocur it for 3D printing, thereby forming an intermediate with a specific crystal lattice shape. Since 3D printing first prints the dual-curing resin in the XY plane, and then sequentially stacks layers of the XY plane along the Z-axis, the photocuring step is preferably performed on a cross-sectional basis. Furthermore, the wavelength of the UV light can be 360–400 nm, and the irradiation time can be 0.5–4 seconds, without particular limitation.
[0040] Stretching step S3
[0041] The stretching step S3 involves applying stress to the intermediate body in the stretching direction according to the stretching ratio of the desired size to stretch it into a stretched body. In this embodiment, the photocuring step and the stretching step can be performed simultaneously.
[0042] then, Figure 3The diagram shows an intermediate with a specific lattice shape, and the arrows in the figure indicate the direction of stress application. In an embodiment, the stress is applied by contact stretching of the intermediate. For contact stretching, known stretching devices can be used, such as a metal rope stretching device with a small clamp at one end and a tension coil at the other end; there are no particular limitations. Furthermore, generally, the stretching speed can be between 100 and 600 mm / min to prevent poor stretching efficiency or damage to the intermediate during the stretching process. In practical applications, the stress is applied at one end along the length of the intermediate. Specifically, there are two stretching methods, the first being... Figure 3 As shown in (a), one end of the intermediate is fixed (without arrow), and stress is applied to the corresponding other end (with arrow) to stretch the intermediate in the direction of the arrow. Also, the second method... Figure 3 As shown in (b), stress is applied to both ends of the intermediate body in the direction to be stretched (e.g., the Y-axis direction), and stress is simultaneously applied to these two ends in the direction of the arrow to stretch the intermediate body.
[0043] Specifically, the stretching process can be performed as follows: Assuming stretching is performed in the Z direction, support structures of suitable strength are designed at the top and bottom of the intermediate body in the Z direction. Clamps or jigs are used to clamp / fix the support structures at the top and bottom of the intermediate body, respectively, to apply stress to one or both sides of the top and bottom, causing the intermediate body to deform in the Z direction, thus obtaining a stretched body conforming to the specified dimensions. Similarly, when stretching in the X or Y direction, support structures of suitable strength are designed at the left and right or front and back (i.e., both ends of the X or Y direction) of the intermediate body. Clamps or jigs are used to clamp / fix the intermediate body at the left and right or front and back positions, respectively, to apply stress to one or both sides of the left and right or front and back, causing the intermediate body to deform in the X or Y direction, thus obtaining a stretched body conforming to the specified dimensions.
[0044] Furthermore, Figure 4 This diagram illustrates the changes in the shape (size) of an intermediate when stress is applied in different directions. The arrows in the diagram indicate the direction of stress application. In practical applications, assuming the intermediate without stress is A, when stress is applied, it is crucial to ensure that the crystal structure of the intermediate is not destroyed, but rather that the intermediate is stretched proportionally. Therefore, when the direction of stress is perpendicular to the photocuring section (Z-direction), the crystal structure is enlarged proportionally without being destroyed, resulting in a stretched cuboid B with a dimension in the Z-direction larger than its dimensions in the X and Y directions. Similarly, when the direction of stress is parallel to the photocuring section (X-direction), the crystal structure is enlarged proportionally without being destroyed, resulting in a stretched cuboid C with a dimension in the X-direction larger than its dimensions in the Z-direction.
[0045] Furthermore, as mentioned above, since the dimensions change after stretching, pre-compensation must be performed in advance when designing the intermediate body. For example, if the intermediate body is to be stretched in the X or Y direction, the Z-direction dimension of the resulting stretched body will be smaller. Therefore, pre-compensation must be performed on the Z-direction dimension of the intermediate body to obtain the desired stretched body. Specifically, to obtain stretched bodies and 3D printed bodies that meet specifications, necessary dimensional parameter compensation can be performed in advance on the intermediate body's design file. Based on this dimensional parameter compensation, the amount of dual-curing resin used can be adjusted to obtain the pre-compensated intermediate body. For example, when stretching the intermediate body in the X direction, if based on previous stretching experience, the Z-direction dimension of the resulting stretched body is 50% smaller than the Z-direction dimension of the intermediate body, then the Z-direction dimension of the intermediate body needs to be pre-compensated by 100%; that is, the Z-direction dimension of the pre-compensated intermediate body needs to be increased by 100% compared to the original Z-direction dimension of the intermediate body. Wherein, the pre-compensation dimension (the percentage increase in the original dimension) = [(1 / (1-the percentage decrease in dimension))-1]*%, that is, [(1 / (1-50%))-1]*% = 100%.
[0046] In practical applications, to maximize 3D printing efficiency, the stress can be applied more than twice, and the location of the first stress application can differ from the location of the second (and subsequent) stress applications. Specifically, as follows... Figure 3 As shown in (b), one end in the Y direction (upper arrow) can be stretched first, and then the other end in the Y direction (lower arrow) can be stretched, or vice versa, and is not limited to this.
[0047] Thermosetting step S4
[0048] The thermosetting step S4 involves heating the stretched body to thermoset and shape it, thereby forming a 3D printed body. Specifically, since this invention uses a dual-curing resin, which is stretched to the target size after photocuring, it is then heated to shape the stretched body into a 3D printed body. Here, because this dual-curing resin does not expand or shrink during heat setting (i.e., dimensional setting), the volume of the 3D printed body after the thermosetting step is equal to that of the stretched body. Furthermore, the heating temperature can be 110–120°C, and the heating time can be 2–6 hours, without particular limitation.
[0049] Repair step S5
[0050] like Figure 2As shown, a trimming step S5 can be included after the thermosetting step S4 if necessary, which removes a portion of the stretched body after the thermosetting step to form a 3D printed body. Since 3D printing is performed layer by layer, in order to ensure smooth printing and structural stability, additional supports are sometimes added to a portion of the intermediate body in addition to the target structure during structural design. After the intermediate body is stretched into a stretched body and undergoes the thermosetting step, a trimming step is preferably performed to remove the additional supports.
[0051] Example
[0052] The present invention will now be described in detail through various embodiments and comparative examples, but the present invention is not limited to these embodiments and comparative examples.
[0053] Reference Examples, Examples 1-3 and Comparative Examples
[0054] First, according to Table 1 below, different stresses were applied in the X direction to intermediates with specific lattice shapes, and 3D printed bodies of Examples 1 to 3 and Comparative Examples were produced according to steps S1 to S4. Furthermore, a 3D printed body without the stretching step was used as a reference example.
[0055] Table 1
[0056]
[0057] Table 1 shows that when stresses of 0.1N, 0.2N, 0.5N, and 1N are applied to the intermediate in the X direction, the length of the stretched body is increased from 155mm to 160mm, 180mm, 188mm, and 230mm, respectively. This corresponds to elongation rates of 3.2%, 16.1%, 21.3%, and 48.3% for Examples 1-3 and the Comparative Example, respectively. This demonstrates a positive correlation between stress intensity and the elongation / elongation rate. Furthermore, Table 1 also shows that the lattice size changes with stretching, and the amount of change in lattice size is positively correlated with stress intensity.
[0058] Next, as Figure 5 As shown, Figure 5 From left to right, the 3D printed bodies are those of the reference example, Example 3, and comparative example, respectively. Figure 5 It can be seen that the lattice structure of the 3D printed body in the comparative example fractured, i.e., the lattice change after stretching was too high (49.5%), and therefore unsatisfactory. In contrast, the 3D printed body in Example 3 still retains a complete lattice structure, only the lattice structure is scaled up proportionally. That is to say, the lattice change after stretching in Examples 1 to 3 is within the allowable range, i.e., the lattice structure is not destroyed, and the lattice spacing can be stretched proportionally in the stretching direction.
[0059] Furthermore, as shown in Table 1, the elongation rate (X direction) in Examples 1-3 ranges from 3.2% to 21.3%, while the dimensional shrinkage rate in the Z direction ranges from -4.3% to -32.3% (this negative value indicates dimensional shrinkage). Therefore, the non-elongation direction (Z direction) requires pre-compensation due to dimensional shrinkage. Next, taking Example 3 as an example, since its Z direction dimensional shrinkage is 32.3%, it can be calculated that under the conditions of Example 3, the Z direction dimension of the intermediate needs to be pre-compensated by 47.7%, meaning the Z direction dimension of the pre-compensated intermediate needs to be increased by 47.7% compared to the original Z direction dimension. Wherein, the pre-compensated dimension (increase in original dimension) = [(1 / (1-32.3%))-1]*% = 47.7%.
[0060] Furthermore, as shown in Table 1 above, the tensile stress of the present invention is preferably in the range of 0.1N to 0.5N. If the tensile stress is less than 0.1N, the stretch length / stretch ratio is too low, and the effect of the present invention cannot be achieved; if the tensile stress is greater than 0.5N, the crystal structure may be destroyed, resulting in the inability to obtain a good 3D printed body. In addition, if a dual-curing resin with different properties is used, the preferred range of tensile stress will also be different, and it is not limited thereto.
[0061] In summary, the 3D printing method of the present invention improves the efficiency of 3D printing and addresses the limitations of machine size due to the use of dual-curing resin and the above-described steps.
[0062] The 3D printed body of this invention is manufactured using the 3D printing method described above. The 3D printed body manufactured by the method of this invention is not limited by the table size in the XY direction of the 3D printer stage, and the manufacturing cost can be reduced due to the improved printing efficiency.
[0063] This invention is not limited to the above embodiments. Various modifications can be made within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included within the technical scope of this invention.
Claims
1. A 3D printing method, characterized in that, Include: The resin supply step provides a dual-curing resin; In the photocuring step, UV light is irradiated onto the dual-curing resin to perform 3D printing, thereby forming an intermediate with a specific lattice shape; In the stretching step, stress is applied to the intermediate body in the stretching direction according to the stretching ratio of the desired size to stretch and form a stretched body; as well as Thermosetting step: The stretched body is heated to thermoset and shape it to form a 3D printed body; During the 3D printing process, the dimensions of the intermediate in the non-stretched direction are pre-compensated based on the stretching ratio.
2. The 3D printing method according to claim 1, characterized in that, The photocuring step and the stretching step are performed simultaneously.
3. The 3D printing method according to claim 1 or 2, characterized in that, The photocuring step is performed using cross-sections as the curing unit.
4. The 3D printing method according to claim 1 or 2, characterized in that, In the stretching step, the stress is applied by contact stretching of the intermediate.
5. The 3D printing method according to claim 1 or 2, characterized in that, In the stretching step, the stress intensity is 0.1 to 0.5 N.
6. The 3D printing method according to claim 5, characterized in that, The stress is applied at one end of the intermediate body along its length.
7. The 3D printing method according to claim 6, characterized in that, The stress is applied more than twice.
8. The 3D printing method according to claim 7, characterized in that, The stress is applied twice, and the location where the stress is applied for the first time is different from the location where the stress is applied for the second time.
9. The 3D printing method according to claim 1 or 2, characterized in that, The stress is applied in a direction parallel to the cross-section of the photocured material.
10. The 3D printing method according to claim 1 or 2, characterized in that, The stress is applied in a direction perpendicular to the cross section of the photocured material.
11. The 3D printing method according to claim 1 or 2, characterized in that, The process includes a finishing step following the thermosetting step, which removes a portion of the stretched body after the thermosetting step to form the 3D printed body.
12. A 3D printed molded body, characterized in that, Manufactured by the 3D printing method according to any one of claims 1 to 7.