What is Selective Heat Sintering?
Selective Heat Sintering (SHS) is a relatively new 3D printing technology presented as an alternative to Selective Laser Sintering (SLS). It simultaneously resembles three other 3D printing methods: SLS, FDM, and DLP. It is virtually identical to the first one, with the only difference being the use of a thermal unit instead of a laser for powder sintering.
This same fact provides a similarity to the second method, and the use of infrared radiation with a specific wavelength as the heat source brings selective heat sintering somewhat closer to DLP technology. Nevertheless, the difference even between selective heat and laser sintering is quite significant, and in this article, we will reveal all the details and answer all questions regarding the SHS technique.
How Does It Work?
To begin with, you should prepare a 3D modelfor 3D printing, check it for errors, and fix them if necessary (for example, in the NetFabb program). After that, the model is loaded into slicer software, where it is prepared specifically for reproduction on a 3D printer: print settings are configured, slicing occurs, and supports are generated. The finished file (usually in STL format) is loaded into the 3D printer, after which printing can begin.
From the introduction, you already know that the main active element in this methodology is an infrared radiation source. But how do you filter this type of radiation? The answer is simple: through wavelength. Depending on it, some materials can transmit heat, while others reflect it. Selective heat sintering happens like this: a pattern corresponding to the inverted cross-section of the current layer of the object is applied to a quartz glass plate (mask). This pattern is applied using a special material that reflects IR radiation.
The amount of consumable material required to build one layer is supplied to the build platform. A special roller levels the powder and removes excess. The quartz plate is positioned between the build area and the radiation source. Once everything is ready, the sintering of the first layer begins. Since the radiation passes through the plate, those parts that reflect the radiation leave no trace on the build platform. The remaining areas of the powder are sintered together.
Upon completion of the first layer, the build platform lowers by one layer level, the next portion of powder is applied, the old pattern is removed from the quartz plate, and a new one is applied. In this manner, the entire model is built. After 3D printing is finished, the product is extracted from the 3D printer, removed from the platform, and cleaned of excess material. Post-processing is performed if necessary.
Features of the Methodology
Selective Heat Sintering stands out from other industrial 3D printing methods due to its speed and simplicity in manufacturing products. Unlike most technologies, the construction of a single layer occurs at one moment in time, meaning all areas of the layer are baked simultaneously. Thus, reproducing one layer takes about 1-2 seconds. Meanwhile, applying the pattern to the quartz plate takes about 10 seconds. Compared to laser methodologies, where sintering takes several minutes, the difference is quite substantial. Furthermore, using a thermal unit instead of a laser significantly reduces the price of 3D printing devices of this class. For the same reason, the dimensions of SHS 3D printers are close to those of budget-class devices.
Advantages:
- High-speed 3D printing;
- High precision in reproducing objects;
- Possibility of creating products with complex geometry;
- Compact 3D printers;
- Savings on consumables due to the possibility of their reuse.
The disadvantages include lower strength of finished products compared to objects manufactured by other industrial 3D printing methods. This is due to the materials used, which we will discuss below.
Materials Used
Unfortunately, selective heat sintering cannot use the entire range of materials available for SLS technology, as thermal radiation is insufficient to sinter many metal powders. For this reason, various filaments and low-melting metals are mainly found as consumables in the SHS methodology. Moreover, products made from the latter often require additional firing to achieve maximum strength.
Selective Heat Sintering: Applications
The main area of application for this methodology in industry is prototyping. Due to the insufficient strength of the products, using them as end-use parts makes little sense. However, high detail and reproduction speed make selective heat sintering highly sought after in the engineering, design, and architectural fields. Furthermore, this 3D printing methodology is ideal for designers and artists.
With its help, excellent models are produced, and most materials also respond very well to post-processing. Therefore, selective heat sintering is often chosen in the educational sector to create various teaching models. Finally, we invite you to take a look at our online store, where a huge amount of equipment and components for 3D printing and 3D printers are presented, and to check out other articles about types of 3D printing. For all questions, contact us via any convenient method listed in the "Contacts" section.
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