This is the first draft of the large scale 3d printing protocol for granulated thermoplastics. The main purpose of this document is to share the key steps of operating, preparation, data entry, and optimization procedures while handling the robotic 3d printing equipment. One main aspect of this protocol is that it is independent of specific 3d printing hardware or software setups. The aim is to have the users from robotic 3d printing from various technologies follow these steps and be able to set the basics up when it comes to handling such 3d printers.
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The additive manufacturing (AM) of high-quality products requires knowledge of the 3D-printing process and the related design guidelines. Allthough AM has been around for some years, many engineers still lack this knowledge. Therefore, Fontys University of Applied Sciences sets great store by training of engineers, education of engineering students and knowledge sharing on this topic. As an appetiser, this article offers a beginner’s course.
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In this article we investigate the change in wetting behavior of inkjet printed materials on either hydrophilic or hydrophobic plasma treated patterns, to determine the minimum obtainable track width using selective patterned μPlasma printing. For Hexamethyl-Disiloxane (HMDSO)/N2 plasma, a decrease in surface energy of approx. 44 mN/m was measured. This resulted in a change in contact angle for water from <10 up to 105 degrees, and from 32 up to 46 degrees for Diethyleneglycol-Dimethaclylate (DEGDMA). For both the nitrogen, air and HMDSO/N2 plasma single pixel wide track widths of approx. 320 μm were measured at a plasma print height of 50 μm. Combining hydrophilic pretreatment of the glass substrate, by UV/Ozone or air μPlasma printing, with hydrophobic HMDSO/N2 plasma, the smallest hydrophilic area found was in the order of 300 μm as well.
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Inkjet printing is a rapidly growing technology for depositing functional materials in the production of organic electronics. Challenges lie among others in the printing of high resolution patterns with high aspect ratio of functional materials to obtain the needed functionality like e.g. conductivity. μPlasma printing is a technology which combines atmospheric plasma treatment with the versatility of digital on demand printing technology to selectively change the wetting behaviour of materials. In earlier research it was shown that with μPlasma printing it is possible to selectively improve the wetting behaviour of functional inks on polymer substrates using atmospheric air plasma. In this investigation we show it is possible to selectively change the substrate wetting behaviour using combinations of different plasmas and patterned printing. For air and nitrogen plasmas, increased wetting of printed materials could be achieved on both polycarbonate and glass substrates. A minimal track width of 320 μm for a 200 μm wide plasma needle was achieved. A combination of N2 with HMDSO plasma increases the contact angle for water up from <100 to 1050 and from 320 to 460 for DEGDMA making the substrate more hydrophobic. Furthermore using N2-plasma in combination with a N2/HMDSO plasma, hydrophobic tracks could be printed with similar minimal track width. Combining both N2 -plasma and N2/HMDSO plasma treatments show promising results to further decrease the track width to even smaller values.
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This study explores the shape-morphing behavior of 4D-printed structures made from Polylactic Acid (PLA), a prominent bio-sourced shape-memory polymer. Focusing on the response of these structures to thermal stimuli, this research investigates how various printing parameters influence their morphing capabilities. The experimental approach integrates design and slicing, printing using fused deposition modeling (FDM), and a post-printing activation phase in a controlled laboratory environment. This process aims to replicate the external stimuli that induce shape morphing, highlighting the dynamic potential of 4D printing. Utilizing Taguchi’s Design of Experiments (DoE), this study examines the effects of printing speed, layer height, layer width, nozzle temperature, bed temperature, and activation temperature on the morphing behavior. The analysis includes precise measurements of deformation parameters, providing a comprehensive understanding of the morphing process. Regression models demonstrate strong correlations with observed data, suggesting their effectiveness in predicting responses based on control parameters. Additionally, finite element analysis (FEA) modeling successfully predicts the performance of these structures, validating its application as a design tool in 4D printing. This research contributes to the understanding of 4D printing dynamics and offers insights for optimizing printing processes to harness the full potential of shape-morphing materials. It sets a foundation for future research, particularly in exploring the relationship between printing parameters and the functional capabilities of 4D-printed structures.
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Currently the advances in the field of 3D printing are causing a revolution in the (bio-)medical field. With applications ranging from patient-specific anatomical models for surgical preparation to prosthetic limbs and even scaffolds for tissue engineering, the possibilities seem endless. Today, the most widely used method is FDM printing. However, there is still a limited range of biodegradable and biocompatible materials available. Moreover, printed implants like for instance cardiovascular stents require higher resolution than is possible to reach with FDM. High resolution is crucial to avoid e.g. bacterial growth and aid to mechanical strength of the implant. For this reason, it would be interesting to consider stereolithography as alternative to FDM for applications in the (bio-) medical field. Stereolithography uses photopolymerizable resins to make high resolution prints. Because the amount of commercially available resins is limited and hardly biocompatible, here we investigate the possibility of using acrylates and vinylesters in an effort to expand the existing arsenal of biocompatible resins. Mechanical properties are tailorable by varying the crosslink density and by varying the spacer length. To facilitate rapid production of high-resolution prints we use masked SLA (mSLA) as an alternative to conventional SLA. mSLA cures an entire layer at a time and therefore uses less time to complete a print than conventional SLA. Additionally, with mSLA it takes the same time to make 10 prints as it would to make only one. Several formulations were prepared and tested for printability and mechanical strength.
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This study aims to provide an in-depth characterization of the intelligent behaviour exhibited by structures fabricated using fused deposition modelling (FDM) printing technology. The primary objective is to understand the variability in the shape-morphing behaviour of additively manufactured PLA structures. A comprehensive analysis is conducted to shed light on the impact of various factors on shape transformation, encompassing both working and printing parameters. To establish the relationship between the printing and working parameters with the shape morphing characteristics, the experimental procedure employs Taguchi's method design of experiments. Notably, the study quantitatively reveals the extent of these parameters' impact on the characteristics.
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The working hypothesis for this research project is that it is possible to develop a new functional polymer printing process for the direct application of conductive polymer onto textiles. We will use the basic extrusion technology that is currently applied in 3D printing. Thus the aim is also expanding the knowledge and knowhow base of 3D printing and make this technology applicable for deposition of functional polymers on textiles in such a way that process parameters are clearly understood, and pre-defined final product specifications can be met. Thus the challenge is to apply conductive tracks with a simple one step process that fits the current textile production processes. This means that investigating polymer deposition onto textiles of bio based polymers like PLA, doped with carbon could be a versatile route to achieving economic and sustainable conducting textiles. If the mechanism underlying the bonding of doped PLA with textiles can be controlled for processing then a new route to achieving conductive grids would be opened.Paper written by the Saxion chair Smart Functional Materials and The Unversity of Twente for and accepted by the Autex Conference 2013 (22-24 May 2013, Dresden, Germany).
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This paper describes the results of a second year Expo project team of Fontys Engineering, department Mechanical Engineering. During this research the design of a configurable damped spring design has been investigated. A calculation tool has been defined and validated using a Nylon 3D printed spring prototype. Also a theoretical design of a stainless steel spring has been made including stress calculations. Finally characterization tests on damping properties have been performed.
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A substantial amount of studies have addressed the influence of sound on human performance. In many of these, however, the large acoustic differences between experimental conditions prevent a direct translation of the results to realistic effects of room acoustic interventions. This review identifies those studies which can be, in principle, translated to (changes in) room acoustic parameters and adds to the knowledge about the influence of the indoor sound environment on people. The review procedure is based on the effect room acoustics can have on the relevant quantifiers of the sound environment in a room or space. 272 papers containing empirical findings on the influence of sound or noise on some measure of human performance were found. Of these, only 12 papers complied with this review's criteria. A conceptual framework is suggested based on the analysis of results, positioning the role of room acoustics in the influence of sound on task performance. Furthermore, valuable insights are pre- sented that can be used in future studies on this topic. Whi le the influence of the sound environment on performance is clearly an issue in many situations, evidence regarding the effectiveness of strategies to control the sound environment by room acoustic design is lacking and should be a focus area in future studies.
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