Читать книгу 3D Printing of Foods - C. Anandharamakrishnan - Страница 44

Selective sintering is the process of binding the powdered materials together to form a solid 3D construct using a laser or hot air as the power source. The movement of the 3D printer is controlled automatically by directing the axis movements at pre‐defined points in space according to the 3D model. The power source is applied to the powdered bed that selectively fuses the powdered particles in a layer‐by‐layer manner for fabrication of desired 3D structure (Diaz et al. 2016). After scanning of each cross‐section of structure, a new layer of powder is dropped and is sintered using the power source that leads to a 3D structure (Figure 2.9). Once the printing process is completed, the formed 3D structure is post‐processed for the removal of unfused powder thereby ensuring the smooth finishing quality of the 3D prints (Diaz et al. 2017). The sintering process is mostly applied for metals and ceramics 3D printing. However, for food applications, studies are being put forth for the development of sugar‐based confectionery 3D printed products (Fuh et al. 2015). The advantage of this technique when applied to foods is the use of the unfused powdered particles for the next cycle of printing and the feasibility for the fabrication of the complex internal designs. Compare to the extrusion technology, the selective sintering process allows for the construction of overhanging 3D structures with greater resolution (Liu and Zhang 2019). However, the sintering process is limited to powdered material such as sugar, starch, and fat. This limitation can be overviewed by the design freedom, high productivity, and throughput of the sintering technology.

Figure 2.9 Schematic diagram of selective laser printing.