Additive manufacturing machines produce 3D objects by building up layers of material. Some additive manufacturing machines are commonly referred to as “3D printers.” 3D printers and other additive manufacturing machines make it possible to convert a CAD (computer aided design) model or other digital representation of an object into the physical object. The model data may be processed into slices each defining that part of a layer or layers of build material to be formed into the object.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration specific examples in which the disclosure may be practiced. It is to be understood that other examples may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense, and the scope of the present disclosure is defined by the appended claims. It is to be understood that features of the various examples described herein may be combined, in part or whole, with each other, unless specifically noted otherwise.
In some additive manufacturing processes, thermic energy is used to fuse together the particles in a powdered build material to form a solid object. Thermic energy to fuse the build material may be generated, for example, by applying a liquid fusing agent to a thin layer of powdered build material in a pattern based on the object slice and then exposing the patterned area to fusing energy. Fusing energy absorbing components in the fusing agent absorb fusing energy to help sinter, melt or otherwise fuse the build material. The process is repeated layer by layer and slice by slice to complete the object.
Thermic source 14 can be sealably contained by enclosure 12 and optical filter 16. In one example, enclosure 12 and optical filter 16 maintain cavity 18, containing thermic source 14, at a negative pressure. Thermic source 14 is a black body radiator that emits thermal radiation. With respect to thermic source 14 of fusing system 10, thermic source 14 can include any suitable number and type of thermic sources to heat and irradiate a build material. Thermic source 14 including lower color temperature warming lamps and higher color temperature fusing lamps can provide control for heating and fusing of a build material. Thermic source 14 can include warming and fusing sources 24, 26. Thermic source 14 emits a spectrum of radiated wavelengths. Fusing source 26 and warming source 24 can have differing emission spectrums. Fusing source 26 can include more near-infrared (IR) content, or wavelengths, than warming source 24. Warming source 24 can include more mid-IR wavelength. In one example, fusing source 26 primarily includes IR wavelengths of 0.75 to 1.5 micrometre (μm). In one example, warming source 24 primarily includes IR wavelengths of 1.5 to 4.0 micro-meters (μm).
Fusing source 26 can be of higher color temperature to sufficiently heat fusing agent 72 and build material to selectively fuse build the build material 70. Warming source 24 can be of lower color temperature to selectively heat the build material without causing build material to fuse. In one example, fusing source 26 has a 2750 degree Kelvin color temperature. Fusing source 26 can include a series of thermal lamps each being longitudinally arranged in parallel with major axes disposed along the y-axis. In one example, warming source 24 has an 1800 degree Kelvin color temperature. Other color temperatures can also be suitable. A single or multiple warming and fusing sources 24, 26 can be included. Fusing lamp 24 is to irradiate build material with fusing energy. In general, warming and fusing sources 24, 26 each include lamps. Fusing source 26 can include any suitable number and type of lamps to heat and irradiate build material. For example, each of the warming and fusing sources 24, 26 includes quartz infrared halogen lamps with each of the quartz infrared halogen lamps having a segmented filament. Fusing source 26 can include a series of thermal lamps each being longitudinally arranged in parallel with major axes disposed along the y-axis. Similarly, warming source 24 can include a series of thermal lamps each being longitudinally arranged in parallel with major axes disposed along the y-axis.
First major surface 28 of optical filter 16 can have a microstructure refined major surface 32 to filter, or modify, the emission spectrum of thermic source 14 from a first emission spectrum to a second emission spectrum. Second major surface 30 of optical filter 16 can have a microstructure refined major surface 33 to filter, or modify, the emission spectrum of thermic source 14 from a first emission spectrum to a second emission spectrum. An entirety, or only a portion of, first and/or second major surfaces 28, 30 can include microstructure refined major surfaces 32, 33. Microstructure refined major surfaces 32, 33 can be structured to either absorb or reflect selective wavelengths, to suppress the passage of the select wavelengths through optical filter 16 as described further below. Microstructure refined major surfaces 32, 33 can be employed with thermal source 14 to aid in independently controlling the warming and the fusing of build material during the build process of three dimensional objects.
In one example, microstructure refined major surface 32 includes a first surface area 34 and a second surface area 36. First and second surface areas 34, 36 can be independently, or differently, microstructured for independent filtering properties of reflecting or absorbing select wavelengths within the emission spectrum emitted by thermic source 14. For example, first surface area 34 can selectively filter the emission spectrum emitted by thermal source 14 into a second emission spectrum and second surface area 36 can selectively filter the emission spectrum emitted by thermal source 14 into a third emission spectrum. In one example, thermal source 14 includes warming and fusing sources 24, 26 and first and second surface areas 34, 36 are disposed between warming and fusing sources 24, 26 and build zone 22, respectively, for independent filtering of warming and fusing sources 24, 26. In one example, second surface area 36 provides short wave pass filtering and is disposed between fusing source 26 and build zone 22, and first surface area 34 provides long wave pass filtering and is disposed between warming source 24 and build zone 22. Short wave pass filtering provides that wavelengths lower a cut-off wavelength (e.g., 1.5 μm) are allowed to transmit through optical filter 16 while wavelength higher than the cut-off wavelength (e.g., 1.5 μm) are blocked by optical filter 16 either by absorption or reflection. Conversely, long wave pass filtering provides that wavelengths higher a cut-off wavelength (e.g., 1.5 μm) are allowed to transmit through optical filter 16 while wavelength lower than the cut-off wavelength (e.g., 1.5 μm) are blocked by optical filter 16, either by absorption or reflection.
With respect to thermic source 14 of fusing system 10, thermic source 14 can include any suitable number and type of thermic sources to heat and irradiate build material. Thermic source 14 including lower color temperature warming lamps and higher color temperature fusing lamps can provide control for heating and fusing of build material. Thermic source 14 illustrated in FIGS. 5A-8B include warming and fusing sources 24, 26. Fusing source 26 can be of higher color temperature to sufficiently heat fusing agent 72 and build material 70 to selectively fuse build the build material 70. Warming source 24 can be of lower color temperature to selectively heat the build material 70 without causing fuse build. In one example, fusing source 26 has a 2750 degree Kelvin color temperature. Fusing source 26 can include a series of thermal lamps each being longitudinally arranged in parallel with major axes disposed along the y-axis. In one example, warming source 24 has an 1800 degree Kelvin color temperature. Other color temperatures can also be suitable. A single or multiple warming and fusing sources 24, 26 can be included. Fusing lamp 24 is to irradiate build material 70 with fusing energy.
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Although specific examples have been illustrated and described herein, a variety of alternate and/or equivalent implementations may be substituted for the specific examples shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific examples discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof.
Filing Document | Filing Date | Country | Kind |
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PCT/US2017/029346 | 4/25/2017 | WO | 00 |