Fused deposition modeling has become the most common 3D printing technology in both the industry and the private sector, due to its easy application and low price. Although some companies provide parameter sets that are perfectly adapted for their machines and filaments, a great variety of materials that can be processed on arbitrary printers are also available. Usually, the operator has to figure out ideal printing parameters in order to achieve high-quality results. In this work, an approach is presented relating the conclusions of differential scanning calorimetry, including the melting and glass transition temperatures and the decomposition points, to the printout quality. To give an overview of the common materials and to correlate the behavior of the printing parameters, 16 different filaments categorized into groups of plastics without additives, metals and carbon, woods, and stones have been investigated. Heat towers have been printed with each filament, whereby the individual floors in 5 °C steps represent the nozzle temperatures and show features for direct comparison. As a main result, it is shown that the optimal printing quality is achieved with temperatures on the colder end of the range between melting and decomposition.
Combined with the increased significance of additive manufacturing technologies in recent years, the FDM-process in particular became more and more important and widespread in private and industrial applications. In the course of the development of a variety of material types, a validation for technical utilization is of great interest. For that reason, standardized samples in three different layer orientations, made of 16 different filament materials, were FDM-printed and tensile tested at room temperature in order to determine their mechanical behavior. Besides the usual plastic types for FDM-printing, such as PLA, ABS or PETG, compound filaments from the four categories metal, carbon, wood, and stone were examined. Carbon showed for any technical applications the most practical results, since the particles increase overall strength and simultaneously contribute to reduced weight. The other composite materials too, for environmental and eco-friendly reasons, are still of interest, although tests have shown that no significant change in resilience has occurred. Moreover, it is found that a crosswise printing direction leads to the best results.
Since the processing of plastics by additive manufacturing techniques, for example, fused deposition modeling, has become quite common, it is mainly used for the production of unique pieces for private consumption as well as for prototyping in industry. In order to professionally manufacture plastic components in large amounts, due to time, cost, and quality factors, injection molding is more suitable. Nevertheless, it is of great interest to print plastic parts in small batch series for technical tasks. In this paper, FDM-produced tensile samples, made from 16 materials, printed in three orientations, are compared to compression molded components. In addition to ordinary filaments, composite materials with metal-, carbon-, wood-, and stone-additives are also examined. While some cavities emerged in both printed and molded samples, the results support the hypothesis that the mechanical properties depend on the components’ densities.
Worldwide, stroke is the third cause of disability. The majority of people affected by this disease cannot perform activities of daily living. Bringing the therapy to the patients' home is complex, and in literature, there are still open challenges to face. Starting from therapists' and patients' needs, this paper describes a possible solution: HANDY, a rehabilitative active hand exoskeleton for post-stroke patients. With a desktop application, they perform three different types of exercises: passive, active and based on activities of daily living. They can also control the exoskeleton themselves in a serious-game approach with a leap motion controller. We evaluated our method with patients at the Villa Beretta rehabilitative center. Preliminary results from the session about comfort, usability and willingness to utilize the system are promising.
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