PARTS AND OUTER LAYERS HAVING DIFFERING PHYSICAL PROPERTIES
Some examples include a computer-readable medium storing executable instructions which, when executed by a processor, are to cause the processor to receive electronic data describing a part to be manufactured in a three-dimensional additive manufacturing process; develop instructions using the electronic data for creating an outer layer on a surface of the part in the additive manufacturing process, where the outer layer having a physical property that differs from that of the surface of the part; and manufacture the part using the instructions.
Three-dimensional printed parts that have been manufactured using an additive manufacturing process may contain surface imperfections resulting from the additive manufacturing process. These surface imperfections may be removed manually during post-processing to create the final desired shape, texture, and/or color. For example, a part manufactured using certain additive manufacturing processes may have small artifacts or imperfections on the exterior. These imperfections or irregularities may be removed by chemical or mechanical means. Bead blasting is an example of a mechanical post-processing method in which the exterior surface of a manufactured part is ablated using a pressurized stream of air or other fluid containing small, abrasive particles or beads.
Various examples will be described below referring to the following figures:
An additive manufacturing system begins building a three-dimensional (3D) part by receiving data comprising a 3D model of the part to be manufactured. The model may contain surface color information, for example, color information supplied by texture mapping data in the 3D model. The manufacturing system processes the 3D model data, which may include surface color information, to determine the processing parameters of the part. For example, the parameters may specify that a color layer be formed on the exterior surface of one or more portions of the part.
While processing the 3D model, the system may also determine where post-processing may occur on the surface of the part, for example, ablating the surface using bead blasting to remove surface irregularities in vertical walls. In those locations where such surface removal is anticipated, the system may add an additional thin layer having the same visible color as the underlying portion of the part. This additional outer layer may include a visually imperceptible property or mechanism to contrast the outer layer from the underlying surface. For example, the thin outer layer may be formed using an ultraviolet (UV) fluorescent color that appears to be the same color as the underlying surface under ordinary white light. However, when the 3D part is illuminated by UV light, those areas where post-processing may occur are highlighted by the contrasting fluorescent color. Likewise, the outer layer may be formed using a material with magnetic properties that are not visually perceptible, but which can be sensed using instruments.
A human operator or automated device that is sensitive to the properties of the contrasting outer layer is thus able to remove or ablate the outer layer at predetermined locations until the outer layer is no longer detectable. For example, the ablation process may be stopped when a fluorescent color is no longer observable or when magnetism is no longer detected. When the outer layer is no longer detectable, the underlying portion of the 3D part is considered complete or ready for further processing.
Prior solutions for manual bead blasting may require the user to know what the part and final finish of the part should look like and to make dynamic, real-time decisions about where and how much bead blasting is needed, which may require skill and attention by a highly trained operator. Other prior automated solutions for bead blasting may simply process all portions of a 3D printed part for a preset amount of time, which may not be ideal for all surfaces on the part.
Examples in accordance with the present disclosure include methods for manufacturing a 3D printed part with an outer layer having a non-visually perceptible physical property. Additional examples in accordance with the present disclosure include methods for post-processing a 3D printed part using the outer layer to guide the post-processing.
In one example, outer layer 130 is printed in an additive manufacturing process with the same visible color as the underlying portion of the part 100. For example, the outer layer 130 may include a selected physical property that distinguishes the outer layer 130 from the underlying portions of part 100. As discussed in more detail below, this selected physical property may be a fluorescent color that appears under UV light, a UV or near infrared (IR) color outside the normal visible spectrum, or a higher level of magnetism.
In one example, the outer layer 130 may be printed with a fluorescent color that has the same visible color as the underlying portion of the part 100 when viewed under normal white light (e.g., light having widely dispersed wavelengths predominantly in the visible spectrum of 390-700 nm). When the fluorescent color in the outer layer 130 is viewed under UV light (e.g., light having wavelengths predominantly in the UV spectrum of 10-400 nm), the color fluoresces and produces a color having a distinctly greater brightness than the non-fluorescent color of the underlying portion of the part 100. Thus, under white light, the outer layer 130 is not visibly distinct from the underlying portions of the part 100. However, under UV light, the outer layer 130 appears with a visually distinctive brightness.
Post-processing the part 100 may involve ablating the exterior using a bead blasting apparatus and the outer layer 130 to remove surface imperfections. Here, the part 100 may be bead blasted under UV light to precisely guide the desired location and depth of the ablation process. The outside surface of the part 100 is ablated until the fluorescent outer layer 130 is no longer observable under UV light. In this manner, ablating may be directed at particular locations and not leave an excess of the outer layer 130, while also not removing underlying portions of the part 100, either of which could adversely affect the appearance and dimensional accuracy of the finished part 100.
The non-visually perceptible physical property of the outer layer 130 may also be magnetism, or result from outer layer 130 including a UV or IR color. For example, when outer layer 130 is applied in the additive manufacturing process, a small amount of magnetic particles may be added to the build material. Alternatively, the magnetic property may be supplied in the fusing agent, other build components, or by other means. The outer layer 130 may thus be detected using a magnetic sensor and the ablation process more precisely guided in a manner similar to using a fluorescent color, as discussed above.
As noted, outer layer 130 may also be formed using a color that appears visually the same color as the underlying part 100, but which also includes a reflective UV or IR color component. As used herein, IR colors are those having wavelengths predominantly in the IR spectrum of 700-1,000 nm. These UV and IR colors may be detected using an image sensor. For example, most image sensors manufactured using a charge-coupled device (CCD) or a complimentary metal-oxide semiconductor (CMOS) device are able to sense colors in a range of wavelengths from 350 nm to 1,000 nm (which includes both UV and IR light).
When the outer layer 130 includes a UV or IR color, the outer layer 130 appears as the same visible color as the underlying portions of the part 100. However, when the outer layer 130 is viewed using an image sensor, the UV or IR wavelengths are detected and may be highlighted for a user. In this manner, the outer layer 130 may be detected by an operator 100 using an image sensor and the ablation process more precisely guided in a manner similar to ablation using a fluorescent color, as discussed above.
Alternatively, the non-visually perceptible physical property of the outer layer 130 may be used in automated or partially automated post-processing. For example, the part 100 may include an outer layer 130 having an IR color component. The part 100 may be mounted on a three-axis gimbal that is controlled by an automated bead blasting machine. The bead blasting machine may include an image sensor which continuously detects an image of the surface of the part 100 at the point where the stream of beads impacts the surface. The bead blasting process continues at this location on part 100 until the sensed image no longer contains IR color, whereupon the part 100 is rotated on the gimbal mount to a new location that does contain IR color. When the IR color is no longer detected by the image sensor, post-processing is complete.
The process of developing instructions to create the outer layer 130 in the 3D printer may account for the additional thickness T1 of any color layer 120. By way of example, thickness T1 of color layer 120 may be 0.75 mm, in which case the outer layer 130 may be created at a distance of 0.75 mm from the surface 110 of part 100. Under these circumstances, the visible color of the outer layer 130 may match the visible color of the color layer 120. In addition, the non-visually perceptible physical property of the outer layer 130 differs from this same property of the color layer 120. For example, the fluorescent color of the outer layer 130 may differ from any fluorescence emitted by the color layer 120. Similarly, if magnetism is used as the physical property, the magnetism of the outer layer 130 may differ from the magnetism of the color layer 120.
The method of post-processing the part 100 illustrated in
Referring to
When the part 100 illustrated in
The examples discussed above enhance various additive manufacturing processes by facilitating simpler and more precise post-processing, whether post-processing is automated or performed manually. When manual post-processing is employed, the examples discussed above may not benefit from advanced knowledge of the final dimensions of the manufactured part, and they may not benefit from a high level of skill and attention by a highly trained operator as with prior art solutions.
The above discussion is meant to be illustrative of the principles and various examples of the present disclosure. Numerous variations and modifications will become apparent to those skilled in the art once the above disclosure is fully appreciated. It is intended that the following claims be interpreted to embrace all such variations and modifications.
Claims
1. A computer-readable medium storing executable instructions which, when executed by a processor, are to cause the processor to:
- receive electronic data describing a part to be manufactured in a three-dimensional additive manufacturing process;
- develop instructions using the electronic data for creating an outer layer on a surface of the part in the additive manufacturing process, the outer layer having a physical property that differs from that of the surface of the part; and
- manufacture the part using the instructions.
2. The computer-readable medium of claim 1, wherein the physical property is magnetism, an ultraviolet color, or an infrared color.
3. The computer-readable medium of claim 1, wherein the physical property is a fluorescent color that contrasts with the surface of the part under ultraviolet light.
4. The computer-readable medium of claim 1, wherein the outer layer has varying thicknesses.
5. The computer-readable medium of claim 4, wherein the varying thickness is determined based on the electronic data such that the thickness is greater in positions on the surface of the part where artifacts or imperfections are likely to occur.
6. A computer-readable medium storing executable instructions which, when executed by a processor, are to cause the processor to:
- generate a model of a three-dimensional part, the model including an outer layer abutting a surface of the three-dimensional part, the outer layer and the surface sharing a common visually perceptible color and not sharing a physical property; and
- manufacture the three-dimensional part in accordance with the model and using additive manufacturing.
7. The computer-readable medium of claim 6, wherein the physical property is magnetism, a fluorescent color that contrasts with the surface of the three-dimensional part under ultraviolet light, or an ultraviolet or infrared color.
8. The computer-readable medium of claim 6, wherein the outer layer of the model has a non-uniform thickness.
9. A method comprising:
- receiving electronic data that describes a three-dimensional part to be manufactured in an additive manufacturing process;
- processing the electronic data to develop instructions for creating a three-dimensional outer layer on an exterior surface of the three-dimensional part, the outer layer having a physical property that is not shared by a portion of the part underlying the outer layer; and
- manufacturing the three-dimensional part by additive manufacturing, including using the instructions to manufacture the outer layer.
10. The method of claim 9 wherein the physical property is a fluorescent color which contrasts with the underlying portion of the part under ultraviolet light.
11. The method of claim 9 wherein the physical property is an ultraviolet or infrared color.
12. The method of claim 9 wherein the physical property is magnetism.
13. The method of claim 9 wherein the processing includes developing the instructions based on an expected need for post-processing selected portions of the exterior surface of the part to remove surface imperfections.
14. The method of claim 13 wherein the outer layer has a physical property that is not present on a portion of the part underlying the outer layer.
15. The method of claim 13 wherein the developed instructions specify manufacturing the outer layer on selected portions of the exterior surface of the part, and the manufacturing the part includes using the instructions to manufacture the outer layer on the selected portions of the exterior surface of the part.
Type: Application
Filed: Jan 31, 2018
Publication Date: Nov 12, 2020
Inventors: William E. Hertling (Vancouver, WA), Jeff Porter (Vancouver, WA)
Application Number: 16/605,375