This thesis is an investigation of the TPE filament for Fused Deposition Modelling (FDM) manufacturing method. All the investigations aim to optimize the quality of the filament in order to make Thermoplastic Elastomer (TPE) material possible for FDM manufacturing method. Optimization experiments were made to find out key parameters in the extrusion process that determine the quality of the filament. With the optimal parameters, further investigation of the additive content in the TPE granulate was made to solve the current problem of the filament in practical 3D printing, which the high surface friction massively affects the FDM manufacturing feasibility. The filaments were manufactured by the desktop extruder 3devo filament extruder and the surface friction tests were performed on TribotesterTM. Additionally, discussion was made to summarize the pros and cons of TPE material as well as the significance of 3D printing TPE. Potential application and benefits are mentioned for combining the property of TPE and the advantage of FDM manufacturing. Current state-of-art extrusion equipment and FDM technology are also summarized.

This thesis will address the design and production of the ATC Kolín comapny's logo. Thesis will be supported by the use of CAD/CAM programs. The choice of materials, components and tools will also be specified. Milling strategy will be designed with the PowerMill program. Two different methods of production will be compared. First one is the conventional machining on the FV 25 CNC vertical knee milling plant with the Heidenhain iTNC 530 controlling system. Where as the second one is the additive rapid prototypong technology with the usage of Fused Deposition Modeling method. The thesis is finished by the technical-economic evaluation with analysis and comparison of production alternatives.

Extrusion additive manufacturing technologies may be utilized to fabricate complex geometry devices. However, the success of these additive manufactured devices depends upon their ability to withstand the static and dynamic mechanical loads experienced in service. In this study, quasi-static tensile and cyclic fatigue tests were performed on ULTEM 9085 samples fabricated by fused deposition modeling (FDM). First, tensile tests were conducted following ASTM D638 on three different build orientations with default build parameters to determine the mechanical strength of FDM ULTEM 9085 with those supplied by the vendor. Next, different build parameters (e.g. contour thickness, number of contours, contour depth, raster thickness, and raster angle) were varied to study the effects of those parameters on mechanical strength. Fatigue properties were investigated utilizing the procedure outlined in ASTM D7791. S-N curves were generated using data collected at stress levels of 80%, 60%, 30% and 20% of the ultimate tensile stress with an R-ratio of 0.1 for the build orientation XZY. The contour thickness and raster thickness were increased to 0.030 in. to determine the effect of those two build parameters on tension-tension fatigue life. Next, the modified Goodman approach was used to estimate the fully reversed (R=-1) fatigue life. The initial data suggested that the modified Goodman approach was very conservative. Therefore, four different stress levels of 25%, 20%, 15% and 10% of ultimate tensile stress were used to characterize the fully reversed fatigue properties. Because of the extreme conservatism of the modified Goodman model for this material, a simple phenomenological model was developed to estimate the fatigue life of ULTEM 9085 subjected to fatigue at different R-ratios. / Master of Science

Effective quality improvement in the manufacturing industry is continually pursued. There is an increasing demand for real-time fault detection, and avoidance of destructive post-process testing. Therefore, it is desirable to employ sensors for in-process monitoring, allowing for real-time quality assurance. Chapter 3 describes the application of sensor based monitoring to additive manufacturing, in which sensors are attached to a desktop model fused deposition modeling machine, to collect data during the manufacturing process. A design of experiments plan is conducted to provide insight into the process, particularly the occurrence of process failure. Subsequently, machine learning classification techniques are applied to detect such failure, and successfully demonstrate the future potential of this platform and methodology. Chapter 4 relates the application of online, image-based quantification of the surface quality of workpieces produced by cylindrical turning. Representative samples of cylindrical shafts, machined by turning under various conditions, are utilized, and an apparatus is constructed for acquiring images while the part remains mounted on a lathe. The surface quality of these specimens is analyzed, employing an algebraic graph theoretic approach, and preliminary regression modeling displays an average surface roughness (Ra) prediction error of less than 8%. Prediction occurs in less than 2 seconds, showing the capability for future application in a real-time, quality control setting. Both of these cases, in additive manufacturing and in turning, are validated using real experimental data and analysis, showing application of sensor-based online process monitoring in multiple manufacturing areas. / Master of Science

Unlike traditional stochastic scaffold fabrication techniques, additive manufacturing (AM) can be used to create tissue-specific three-dimensional scaffolds with controlled porosity and pore geometry (meso-structure). However, due to the relatively few biocompatible materials available for processing in AM machines, direct fabrication of tissue scaffolds is limited. To alleviate material limitations and improve feature resolution, a new indirect scaffold fabrication method is developed. A four step fabrication process is explored: Fused Deposition Modeling (FDM) is used to fabricate scaffold patterns of varied pore size and geometry. Next, scaffold patterns are surface treated, and then mineralized via simulated body fluid (SBF); forming a bone-like ceramic throughout the scaffold pattern. Finally, mineralized patterns are heat treated to pyrolyze the pattern and sinter the minerals. Two scaffold meso-structures are tested: "tube" and "backfill." Two pattern materials are tested [acrylonitrile butadiene styrene (ABS) and investment cast wax (ICW)] to determine which material is the most appropriate for mineralization and sintering. Mineralization is improved through plasma surface treatment and dynamic flow conditions. Appropriate burnout and sintering temperatures to remove pattern material are determined experimentally. While the "tube scaffolds" were found to fail structurally, "backfill scaffolds" were successfully created using the new fabrication process. The "backfill scaffold" meso-structure had wall thicknesses of 470 – 530 µm and internal channel diameters of 280 – 340 µm, which is in the range of appropriate pore size for bone tissue engineering. "Backfill scaffolds" alleviated material limitations, and had improved feature resolution compared to current indirect scaffold fabrication processes. / Master of Science

3D-skrivare baserade på FDM-teknik sprider sig snabbt på marknaden på grund av kommersiell tillgänglighet, låga ingångspris och allt mer  användarvänliga enheter. I takt med att additiv tillverkning kommer allt närmare hemmet är det viktigt att veta hur vår hälsa påverkas när vi sitter intill. Partikelbaserade ämnen är en av huvudkomponenterna av luftföroreningar som idag är världens största enskilda miljöhälsorisk. Framtiden för FDM som tillverkningsmetod ser ljus ut, men är tekniken hälsomässigt ljusare än luftföroreningarna dagens masstillverkande fabriker bolmar ut? Denna studie syftar att svara på den föregående frågan med en mängd kvantitativa tester. Partikelkoncentrationer i mikrostorlek jämförs mellan olika inställningar och miljöer med hjälp av två 3D-skrivare i syfte att öka förståelsen och förebygga dessa hälsorisker. Detta projekt bygger på en förstudie (se Bilaga 1) Denna förstudie talar mer detaljerat om vad luftföroreningar är, dess negativa hälsoeffekter samt går igenom konstruktionen av partikelmätaren, vilken i denna används för att mäta partikelkoncentrationer i klassificeringarna PM10 och PM2.5. Totalt genomfördes 19 tester, varav två tester var identiska med syftet att avgöra variansen. Från testerna som jämfört två skrivare kunde medelvärden av partikelkoncentrationer i PM10 eller PM2.5 för skrivaren Stratasys Uprint SE Plus  inte urskiljas från rummens grundvärden. Skrivaren Makerbot Replicator+ visade en snittökning av partikelkoncentrationer i både PM10 och PM2.5 med 60-70% jämfört med grundvärdet. Skillnaden mellan skrivare beror främst på att Stratasys Uprint har en innesluten byggplatta, vilket Makerbot Replicator+ saknar. Partikelkoncentrationen i luften steg markant efter dörren på Stratasys Uprint öppnats och nådde då i de flesta fall värden för PM10, vilka var större än ett hos Makerbot-skrivaren identiskt test. Filamentfärg, rumsstorlek samt ventilation har också en påverkan på rummets koncentration av mikropartiklar, där ett större välventilerat rum når lägre koncentrationer än ett litet rum utan ventilation. Tyvärr har denna typ av studie har ingen standardiserad mätmetod, vilket gör att resultaten blir situationsanpassade och kan ha en varierande precision vid jämförelser mellan studier. Slutligen rekommenderar jag, utifrån studiens resultat att det kan vara värt att satsa på en innesluten skrivare ifall man under längre perioder kommer vistas i närheten av en sådan. Alternativt bör skrivaren placeras i ett ventilerat rum där man inte vistas så ofta. / <p>Betyg 2020-08-21</p>

Master of Science / Department of Mechanical and Nuclear Engineering / Gurpreet Singh / 3D-printing is a popular manufacturing technique for making complex parts or small quantity batches. Currently, the applications of 3D-printing are limited by the material properties of the printed material. The processing parameters of commonly available 3D printing processes constrain the materials used to a small set of primarily plastic materials, which have relatively low strength and electrical conductivity. Adding filler materials has the potential to improve these properties and expand the applications of 3D printed material. Carbon nanomaterials show promise as filler materials due to their extremely high conductivity, strength, and surface area. In this work, Graphite, Carbon Nanotubes, and Carbon Black (CB) were mixed with raw Acrylonitrile Butadiene Styrene (ABS) pellets. The resulting mixture was extruded to form a composite filament. Tensile test specimens and electrical conductivity specimens were manufactured by Fused Deposition Method (FDM) 3D-printing using this composite filament as the feedstock material. Weight percentages of filler materials were varied from 0-20 wt% to see the effect of increasing filler loading on the composite materials. Additional tensile test specimens were fabricated and post-processed with heat and microwave irradiation in attempt to improve adhesion between layers of the 3D-printed materials. Electrical Impedance Spectroscopy tests on 15 wt% Multiwalled Carbon Nanotube (MWCNT) composite specimens showed an increase in DC electrical conductivity of over 6 orders of magnitude compared to neat ABS samples. This 15 wt% specimen had DC electrical conductivity of 8.74x10−6 S/cm, indicating semi-conducting behavior. MWCNT specimens with under 5 wt% filler loading and Graphite specimens with under 1 wt% filler loading showed strong insulating behavior similar to neat ABS. Tensile tests showed increases in tensile strength at 5 wt% CB and 0.5 wt% MWCNT. Placing the specimens in the oven at 135 °C for an hour caused increased the stiffness of the composite specimens.

<div>Fused deposition modeling (FDM) represents one of the most common techniques for rapid proto-typing in additive manufacturing (AM). This work applies image based thermography to monitor the FDM process in-situ. The nozzle temperature, print speed and print orientation were adjusted during the fabrication process of each specimen.</div><div>Experimental and numerical analysis were performed on the fabricated specimens. The combination of the layer wise temperature profile plot and temporal plot provide insights</div><div>for specimens fabricated in x, y and z-axis orientation. For the x-axis orientation build possessing 35 layers, Specimens B16 and B7 printed with nozzle temperature of 225 ➦C and</div><div>235 ➦C respectively, and at printing speed of 60 mm/s and 100 mm/s respectively with the former possessing the highest modulus, yield strength, and ultimate tensile strength. For the y-axis orientation build possessing 59 layers, Specimens B23, B14 and B8 printed with nozzle temperature of 215°C, 225°C and 235°C respectively, and at printing speed of 80 mm/s, 80 mm/s and 60 mm/s respectively with the former possessing the highest modulus and yield strength, while the latter the highest ultimate tensile strength. For the z-axis orientation build possessing 1256 layers, Specimens B6, B24 and B9 printed with nozzle temperature of 235°C, 235°C and 235°C respectively, and at printing speed of 80 mm/s, 80 mm/s and 60 mm/s respectively with the former possessing the highest modulus and ultimate tensile strength, while B24 had the highest yield strength and B9 the lowest modulus, yield strength and ultimate tensile strength. The results show that the prints oriented in the y-axis orientation perform relatively better than prints in the x-axis and z-axis orientation.</div>

This study focuses on novel approaches to the modeling and construction of devices used in ion beam and vacuum systems. Turbulent computational fluid dynamics simulations were performed to model the air flow into an ion funnel system. The results of these simulations were coupled one-way with electrodynamics simulations of the fields generated by the ion funnel. Using the turbulence kinetic energy (k), a spatially varying estimation of the fluctuating component of the velocity field was calculated. These resulting simulations more accurately predicted the ion transmission through the system. Using fused deposition modeling (FDM) novel construction methods for the ion funnel and the vacuum chamber components the ion funnel system utilizes were developed. An FDM fabricated frame, in the shape of the ion funnel, was quickly and inexpensively produced. This frame supported a flexible printed circuit board that served as both the lenses of the ion funnel and power distribution circuit. The transmission of ions was as good as the traditionally constructed ion funnel. The device cost and weighed less and had lower intrinsic impedance, requiring less power to be driven. FDM was also used to produce vacuum components by post-processing using electroplating. Initial tests to determine whether electroplating would adequately produce a hermetic seal for vacuum components were performed. It was observed that thinner plated components could not withstand the stresses required from the gaskets and flanges to adequately seal, subsequently cracking. Thicker samples adequately sealed against atmosphere and maintained this seal over the entire test period. A proof of concept KF-25 full nipple was produced and processed using electroplating. The device was able to reach and ultimate pressure of 1 x 10-6 Torr, however, it was not able to reach the ultimate pressure of the chamber, which was 5 x 10-7 Torr due to the inability to be adequately cleaned of contaminant water.

3D printable materials for RF devices need improvement in order to satisfy the demand for higher frequency and lower loss performance. Characterization of materials that have shown improvements of conductor conductivity have been performed. By using a laser machining technique the loss of a 3D printed 2.45 GHz microstrip Square Open Loop Resonator (SOLR) bandpass filter has been shown to improve by 2.1dB, along with an increase in bandwidth from 10% to 12.7% when compared to a SOLR filter that has not been laser machined. Both laser machined and microwaved silver inks have been mapped for conductivity using a Near Field Microwave Microscope (NFMM) and have shown improvement of conductivity compared to inks that have been cured using standard methods.