This study investigates the influence of ultraviolet (UV) radiation on the mechanical properties of Fused Deposition Modeling (FDM) 3D printed materials, specifically polycarbonate (PC) and polylactic acid (PLA) specimens. The research involves conducting experiments on five test specimens of each material exposed to UV radiation and comparing their mechanical properties to those of five control specimens that remain unexposed. The results reveal a significant mean difference between the mechanical properties of the control and UV-exposed materials. UV radiation caused a decrease in tensile strength for the PC material, while the PLA material exhibited an increase in tensile strength. The impact of UV radiation on PLA was more substantial compared to PC. Flexural strength testing showed an enhancement in strength for the UV-treated materials, with UV treatment having a greater influence on the flexural strength of PLA compared to PC. The mechanical properties of PLA were more significantly impacted by UV radiation than those of PC. The study findings suggest that PC and PLA materials exhibit different responses to UV exposure, which may have implications for their practical applications. Further research is needed to fully understand the underlying mechanisms governing these divergent responses and to optimize the performance of each material under UV radiation.

The material extrusion fused deposition modeling (FDM) technique has become a widely used technique that enables the production of complex parts for various applications. To overcome limitations of PLA material such as low impact toughness, commercially available materials such as UltiMaker Tough PLA were produced to improve the parent PLA material that can be widely applied in many engineering applications. In this study, 3D-printed parts (test specimens) considering six different printing parameters (i.e., layer height, wall thickness, infill density, build plate temperature, printing speed, and printing temperature) are experimentally investigated to understand their impact on the mechanical properties of Tough PLA material. Three different standardized tests of tensile, flexural, and compressive properties were conducted to determine the maximum force and Young’s modulus. These six properties were used as responses in a design of experiment, definitive screening design (DSD), to build six regression models. Analysis of variance (ANOVA) is performed to evaluate the effects of each of the six printing parameters on Tough PLA mechanical properties. It is shown that all regression models are statistically significant (p<0.05) with high values of adjusted and predicted R2. Conducted confirmation tests resulted in low relative errors between experimental and predicted data, indicating that the developed models are adequately accurate and reliable for the prediction of tensile, flexural, and compressive properties of Tough PLA material.

Computed tomography (CT) is a diagnostic imaging process that uses ionising radiation to obtain information about the interior anatomic structure of the human body. Considering that the medical use of ionising radiation implies exposing patients to radiation that may lead to unwanted stochastic effects and that those effects are less probable at lower doses, optimising imaging protocols is of great importance. In this paper, we used an assembled 3D-printed infant head phantom and matched its image quality parameters with those obtained for a commercially available adult head phantom using the imaging protocol dedicated for adult patients. In accordance with the results, an optimised scanning protocol was designed which resulted in dose reductions for paediatric patients while keeping image quality at an adequate level.

The paper explores importance of rapid prototyping technology, as an important part of Industry 4.0, in product development and design process. Current state of this technology is explored in detail, with special focus of places and processes where this technology plays important role inside Industry 4.0. Paper answers several questionssuch as: does this technology have its future inside Industry 4.0, is this technology integral part of Industry 4.0 or just one aspect, has the time come to call this technology rapid manufacturing (of final products) instead of rapid prototyping (of prototypes)?Industry 4.0 implies rapid prototyping of final products, not only its prototypes. Main representative of rapid prototyping technology is additive manufacturing. Today, additive manufacturing technologies do not only serve for prototyping. They are becoming increasingly used for manufacturing of final fully functional products. Product development and design process inside Industry 4.0 must be adopted to new market demands which implies fast development and design and fast manufacturing. The time from initial concept design to the final product manufacturing must be as short as possible. The paper provides answers to the above stated questions. In addition, real examples of product development and design of prototypes and real fully functional products are presented, with a special focus on products and prototypes developed in Bosnia and Herzegovina.

One of the advantages provided by fused deposition modelling (FDM) 3D printing technology is the manufacturing of product materials with infill structure, which provides advantages such as reduced production time, product weight and even the final price. In this paper, the tensile mechanical properties, tensile strength and elastic modulus, of PLA, Tough PLA and PC FDM 3D printed materials with the infill structure were analysed and compared. Also, the influence of infill pattern on tensile properties was analysed. Material testing were performed according to ISO 527-2 standard. All results are statistically analysed and results showed that infill pattern have influence on tensile mechanical properties for all three materials.

One of the advantages of FDM technology is the production of product materials with infill structure. In order to make the most of this advantage, the behaviour of FDM printed material with infill structure under different loads has to be analyzed and understood. Therefore, the goal of this experimental research is to analyze influence of infill density (100%, 80%, 60% and 20%) on tensile mechanical properties (tensile strength and elastic modulus) of PLA antibacterial nanocomposite, tough PLA and ABS-X 3D printed materials.

In this research, an experimental analysis of the influence of layer height, build orientation and post curing on the tensile mechanical properties of SLA 3D printed material was performed. The material "Grey Resin" from the manufacturer Fromlabs was specifically analysed. When it comes to layer height, four different layer heights were analysed, with 160, 100, 50, and 25 microns. Specimens were manufactured in three different build orientations (vertical, side and flat). All specimens were tested with and without post curing (30 min, 60 °C). The results in further text showed that the layer height, build orientation as well as the post curing have an impact on the tensile mechanical properties of the SLA "Grey Resin" material. Also, in addition to the effect on mechanical properties, the paper presents how these factors affect the time of 3D printing.

Widely used additive manufacturing technique for plastic materials is Fused Deposition Modelling (FDM). The FDM technology has gained interest in industry for a wide range of applications, especially today when large number of different materials on the market are available. There are many different manufacturers for the same FDM material where the difference in price goes up to 50%. This experimental study investigates possible difference in strength of the 3D printed PLA material of five different manufacturers. All specimens are 3D printed on Ultimaker S5 printer with the same printing parameters, and they are all the same colour.