Wear and Service Life of 3-D Printed Polymeric Gears

Rapid Prototyping Technologies: 3D Printing Applied in Medicine

Three-dimensional printing technology has been used for more than three decades in many industries, including the automotive and aerospace industries. So far, the use of this technology in medicine has been limited only to 3D printing of anatomical models for educational and training purposes, which is due to the insufficient functional properties of the materials used in the process. Only recent advances in the development of innovative materials have resulted in the flourishing of the use of 3D printing in medicine and pharmacy. Currently, additive manufacturing technology is widely used in clinical fields. Rapid development can be observed in the design of implants and prostheses, the creation of biomedical models tailored to the needs of the patient and the bioprinting of tissues and living scaffolds for regenerative medicine. The purpose of this review is to characterize the most popular 3D printing techniques.

Wear Analysis of 3D-Printed Spur and Herringbone Gears Used in Automated Retail Kiosks Based on Computer Vision and Statistical Methods

This paper focuses on a wear evaluation conducted for prototype spur and herringbone gears made from PET-G filament using additive manufacturing. The main objective of this study is to verify if 3D-printed gears can be considered a reliable choice for long-term exploitation in selected mechanical systems, specifically automated retail kiosks. For this reason, two methods were applied, utilizing: (1) vision-based inspection of the gears' cross-sectional geometry and (2) the statistical characterization of the selected kinematic parameters and torques generated by drives. The former method involves destructive testing and allows for identification of the gears' operation-induced geometric shape evolution, whereas the latter method focuses on searching for nondestructive kinematic and torque-based indicators, which allow tracking of the wear. The novel contribution presented in this paper is the conceptual and experimental application of the identification of the changes of 3D-printed parts' geometric properties resulting from wear. The inspected exploited and non-exploited 3D-printed parts underwent encasing in resin and a curing process, followed by cutting in a specific plane to reveal the desired shapes, before finally being subjected to a vision-based geometric characterization. The authors have experimentally demonstrated, in real industrial conditions, on batch production parts, the usefulness of the presented destructive testing technique providing valid indices for wear identification.

Structural and Tribological Characterization of Carbon and Glass Fabrics Reinforced Epoxy for Bushing Applications Safety

This article investigates the effect of geometrical alternatives for fiber directions on the structural and tribological properties of glass and carbon fibers when molded with epoxy as polymeric composite fabrics for the safety and quality of bushing applications. To confirm the best composite fabric direction, scanning electron microscope and tribological analyses were carried out for the glass and carbon fabrics at horizontal and vertical geometrical alternative orientations. The tribological test was applied using a pin-on-disk tribometer at constant bark velocity of 0.520 m/s against different loads, beginning with 5, 10, 15, and 20 N for the investigated composite samples. The structural measurements demonstrated that the carbon fiber had a high ability to merge with the resin epoxy when compared with the glass fiber. The tribological analysis elucidated that the lower wear volume loss and friction coefficient were obtained when molding the resin epoxy horizontally to the fiber-stacking direction compared with the other vertical direction. Accordingly, the study deduced that the carbon fiber composite material achieves superior wear resistance when molded by resin epoxy horizontally to the direction of tribological wear, which is suitable for several advanced bushing applications.

An Environmentally-Friendly Three-Dimensional Computer-Aided Verification Technique for Plastic Parts

Plastic components play a significant role in conserving and saving energy. Plastic products provide some advantages over metal, including reducing part weight, manufacturing costs, and waste, and increasing corrosion resistance. Environmental sustainability is one of the sustainable development goals (SDGs). Currently, the non-contact computer-aided verification method is frequently employed in the plastic industry due to its high measurement efficiency compared with the conventional contact measuring method. In this study, we proposed an innovative, green three-dimensional (3D) optical inspection technology, which can perform precise 3D optical inspection without spraying anything on the component surface. We carried out the feasibility experiments using two plastic parts with complex geometric shapes under eight different proposed measurement strategies that can be adjusted according to the software interface. We studied and analyzed the differences in 3D optical inspection for building an empirical technical database. Our aim in this study is to propose a technical database for 3D optical measurements of an object without spraying anything to the component’s surface. We found that the research results fulfilled the requirements of the SDGs. Our research results have industrial applicability and practical value because the dimensional average error of the two plastic parts has been controlled at approximately 3 µm and 4.7 µm.