International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

With the development of the world, innovative technologies are increasingly used for the purpose of faster, higher quality and cheaper production of machine parts and household materials. Advantages and disadvantages of conventional and innovative production of metal and polymer products are presented, as well as the possibility of replacing metal parts with plastic ones. The mechanical parameters of different types of materials produced through traditional and innovative production are compared. The comparative analysis shows that both conventional and modern 3D manufacturing have their place in modern industry, taking into account all factors and applications.

In this article, hardness Shore D of 3D printed ABS samples were investigated. The experimental results were analytical and statistically processed.

This work examines the relationship between two of the most important mechanical parameters: shear and tensile strength in 3D printed polymer test specimens using Fused Deposition Modeling. Different types of materials were used, including those that are mechanically strong, easy to print, flexible, and heat-resistant, to determine their behavior. The study was conducted by testing test specimens printed with the same characteristics of percentage filling and pattern, layer height, and printing direction. The ratio between the shear strength and tensile strength of seven polymer materials with 30 % infill in percent was calculated. The values were compared with those of metals and polymers with 100 % density, and an estimate of the coefficient between the two parameters was made.

By utilizing the artificial intelligence capabilities of generative design, the main task was to generate an optimal pulley support model that satisfies the initially applied conditions while reducing the overall mass and volume. The bracket fixation method presents a novel approach to pulley support assemblies. Through Static Stress and Generative Design modules, various angular load applications of 1500 N were considered, and the consequent mechanical characteristics were numerically compared and interpreted. The outcomes of the generative design process provide a firm basis for manufacturing the optimal pulley support model through casting or additive technology.

In this article, the maximum tensile strength and hardness of 3D printed samples of Nylon CF15 Carbon were investigated. 20 test specimens were produced with dimensions according to the ASTM D 638 standard for tensile strength and 3 specimens for Shore D hardness testing. The experimental results were processed statistically.

Ultimately, digitizing cultural heritage is not just about preservation; it is about enriching the cultural narrative, making it inclusive, and ensuring that knowledge and appreciation of our shared history are passed down to future generations. Digitization involves advanced techniques such as 3D scanning, high-resolution photography, and digital modeling. These technologies help create accurate and detailed representations of cultural assets, ensuring that the digital versions retain the original’s integrity and details. Ensuring high reliability for small-sized objects is a crucial challenge in digitizing cultural heritage sites, especially when dealing with objects that lack movement, transporting, low ambient light conditions, reflective material, etc. By incorporating three-dimensional models into the research and dissemination process, cultural heritage institutions can make their work more appealing and accessible to a wider audience, fostering greater appreciation and understanding of our shared cultural heritage.

The growing environmental concern about plastic waste has prompted research into sustainable recycling of polymer, particularly for widely used polymers such as polyethylene from the spools used in the textile industry in the second half of the 20th century. This study investigates the feasibility and optimization of recycling Polypropylene to make filaments suited for 3D printing applications, notably Fused Deposition Modelling (FDM). The study is divided into three phases: collecting and preparing post-consumer Polypropylene spools, extruding recycled Polypropylene into filaments, and optimizing the filament for 3d printing using FDM Technology.
Polyethylene spools are cleaned, shredded, and treated to ensure consistent feedstock quality. The extrusion process entailed controlling factors like temperature, screw speed, and cooling rate to produce filaments with constant diameter with less distortion. Following material characterisation, the printability of recycled Polypropylene filaments was evaluated using an FDM 3D printer. The Taguchi method is used to carefully study the influence of printing parameters such as nozzle temperature, bed temperature, print speed, and layer height to determine optimal parameters. The printed examples showed reasonable dimensional accuracy and layer adhesion, with surface roughness values within acceptable limits for practical applications.
This thorough study plan focuses on recycled Polypropylene as a feasible and sustainable material for FDM 3D printing. The findings indicate that with proper optimization, recycled Polypropylene can match the performance requirements of a variety of applications, helping to reduce waste and promote the circular economy in additive manufacturing. Long-term performance testing and the development of recycling processes will be the primary focus of future research to improve the material’s characteristics and broaden its application range.

Direct Metal Laser Sintering (DMLS) is a revolutionary technology that allows a production of fully functional metal parts directly from a 3D CAD data, eliminating the investment to production tools and technologies which brings considerable cost and time savings. Metal parts made by DMLS technology are fully comparable with casted or machined parts. A range of application of DMLS technologies is very wide – from prototypes, through short-run production to final products. Advantages of DMLS technology are arising along with complexity of parts – more complex geometry of parts (in terms of shape and occurrence of the detail) make DMLS technology even more
economically effective.

In this paper, the tensile strength of the composite material made of onyx and carbon fibers was investigated. Onyx is a material manufactured by the company Mark Forged, which is used for 3D printing of composite materials. It is a thermoplastic filled with carbon fibers used for printing solid and rigid parts. The tensile test according to the standard ISO 527 was carried out experimentally and the numerical results were obtained by numerically modelling the test specimen and simulating the test in Ansys, after which the results obtained experimentally and numerically were compared.

This study aims to present the practical application of the Dentistry 4.0 concept based on obtaining data on the patient’s intraoral situation and bone base using CBCT, processing them into a digital model, creating a digital twin, and then developing an intraprocedural navigation procedure through a dedicated surgical guide and then designing and manufacturing, using 3D printing, implantprosthetic restorations. The study describes the results of the author’s work, indicating the engineering aspects of implant prosthetic treatment based on the description of cases related to the reconstruction of single missing teeth using dental implants implanted in the case of difficult anatomical conditions of the bone base and/or adjacent teeth, with a discussion of the material selection methodology, technological and structural design, using additive manufacturing.
The technology for the design, manufacture and application of implant-prosthetic restorations developed by the author, preceded by a fully navigated implantation procedure of dental screw implants, illustrates in practice the full application of the Dentistry 4.0 concept, where the latest technologies, including primarily computer-aided design and computer-aided CAD/CAM manufacturing, the use of a digital twin, supporting surgical procedures through the use of templates navigating the operator’s actions and additive manufacturing allow for a radical increase in the availability of implant-prosthetic solutions for patients with difficult anatomical conditions, both due to a limited bone base and anomalies of the anatomy of adjacent teeth. Thanks to the latest technology, not only is it possible to perform this type of procedure, but it is also possible to perform the procedure in a short time, with minimal interference in the patient’s tissues and ensuring the optimal shape of the prosthetic restoration itself.

On the filter for fine air purification example the possibilities of additive technologies are shown, which allow to simplify and facilitate significantly the product development process, in particular, the filtering purpose. The results of 3-D modeling of the filter design, as well as 3-D modeling and 3-D printing of the tooling for studying the properties of filter elements to the filter and their structural elements (except for the filter layer) are given. The possibility of questions operative solution in case of adjustment necessity of tooling designs and filter elements at additive technologies application is noted.

In recent years, 3D printing has gradually appeared in people’s field of vision. The addition of wood in thermoplastics improve their some mechanical properties such as tensile and bending modulus without affecting its biodegradability. The decrease in the cost of filaments may enlarge the utilization of biodegradable filaments after the disposal in near future. Smallscale elements used in furniture production, such as connector fittings or fasteners for shelves, may give functional and structural
properties without significant investment. 3D-printed connections are suitable when the the production complex shaped connectors and quick disassembly are required, to reduce the product’s weight and price