Investigation of the structure of plastic products made by 3D printing in sub-terahertz radiation

Subject of study. The structure of plastic products manufactured using fused deposition modeling in the sub-terahertz range with varying parameters of 3D printing, such as the infill pattern and the infill density, is investigated. Aim of study. The influence of 3D printing parameters (such as the infill pattern and infill density percentage) on the optical characteristics of 3D printed plastic products is established to identify the possibilities of sub-terahertz imaging and non-destructive testing of plastic products and assess the necessity of accounting for these parameters in manufacturing terahertz optics elements. Method. Sub-terahertz imaging using a 300-GHz compact radiation source and a terahertz camera. The image resolution was improved by subpixel scanning. Main results. An overview of the applications of fused deposition modeling 3D printing in manufacturing terahertz optics elements is provided. It is noted that most previous studies do not provide comprehensive details of the printing parameters used. Images of plastic objects printed under various 3D printing parameters were captured and the differences in image characteristics were identified, showcasing the impact of the internal sub-wavelength structure on the optical properties of the products. The results indicate the potential to determine the infill density and type of filling pattern in plastic products. Practical significance. Sub-terahertz imaging with radiation from compact sources paired with terahertz cameras offers a promising and competitive alternative for non-destructive testing of 3D-printed plastic items. The necessity for a detailed description of 3D printing parameters to ensure reproducibility in scientific research, especially when designing optical elements for terahertz and sub-terahertz ranges, is emphasized.