El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Production systems need to be monitored because failure to do so can cause a delay in production due to a lack of remote monitoring. There are solutions that provide this information, but they are limited, because they are owned and very expensive solutions. This paper proposes the development of a mobile application for the monitoring of S7-1200 programmable controller variables through Firebase. The goal is to use open-source-type tools to develop a real-time variable monitoring application of a programmable controller capable of hosting a Web server, and the sent data to the Firebase cloud, in order to avoid modifying the driver software and the data stored in memory. The implemented system of sending, handling and presenting variables is developed with tools of open source type, since they have as an advantage to have greater freedom in programming, unlike proprietary solutions or services. The tests were performed on the Siemens S7-1200 controller with a plastic injection molding machine. / Revisión por pares

Dieser Beitrag untersucht die Gültigkeit von 2,5D und 3D Simulationsmodellen des Füllvorgangs beim Spritzgießen. Zur numerischen Approximation dieser Ansätze wird für das 2,5D Verfahren die Software Cadmould 3D-F und für das 3D Verfahren Ansys CFX verwendet. Um das nicht newtonsche Viskositätsverhalten der Polymerschmelze abzubilden, wird in beiden Simulationen ein geeignetes Viskositätsmodell verwendet. Die Ergebnisse des numerischen Füllvorgangs werden anschließend mit experimentellen Daten validiert. / This article examines the validity of 2.5D and 3D simulation models of the filling process in injection molding. To numerically approximate these approaches, the software Cadmould 3D-F is used for the 2.5D method and Ansys CFX for the 3D method. To represent the non-Newtonian viscosity behavior of the polymer melt, a suitable viscosity model is used in both simulations. The results of the numerical filling process are then validated with experimental data.

Resin infusion of composite parts has continually been reaching to achieve laminate quality equal to, or exceeding, the quality produced with prepreg in an autoclave. In order for this to occur, developers must understand the key process variables that go in to producing a laminate with minimal void content. The purpose of this research is to continue efforts in understanding 1) the effect of process conditions on the resultant void content, with a focus on resin infusion flow rate, 2) applying statistical metrics to the formation, location and size of voids formed, and 3) correlate these metrics with the local mechanical properties of the composite laminate. The variation in dispersion and formation of micro-voids and macro-voids varied greatly between the rates of flow the infusion occurred, especially in the non-crimp carbon fiber samples. Higher flow rates led to lower volumes of micro-voids in the beginning section of the carbon fiber laminates with macro-voids being introduced approximately half-way through infusion. This was determined to have occurred decreasing pressure gradient as the flow front moved away from the inlet. This variation in void content per location on the laminate was more evident in the carbon fiber samples than the fiberglass samples. Micro-voids follow void formation modeling especially when coupled with a pressure threshold model. Macro-void formation was also demonstrated to correlate strongly to void formation models when united with void mobility theories and pressure thresholds. There is a quick decrease in mechanical properties after the first 1-2% of voids signaling strength is mostly sensitive to the first 0-2% void content. A slight decrease in SBS was noticed in fiberglass laminates, A-F as v0 increased but not as drastically as represented in the NCF laminates, G and H. The lower clarity in the exponential trend could be due to the lack of samples with v0 greater than 0% but less than 1%. Strength is not well correlated to void content above 2% and could possibly be related to void morphololgy.

The growing negative impacts of non-biodegradable plastics derived from non-renewable materials have created increasing interest throughout the world for new materials that are both biodegradable and renewable, that can be combined with or replace traditional plastics. Plant-based thermoplastic starch (TPS), a promising alternative material to traditional petroleum based resin, is both biodegradable and renewable and has great potential for use in plastic manufacturing processes. Two major obstacles that prevent more widespread use of TPS include; TPS base material, which is typically manufactured in a flake or powder, is incompatible with standard plastics production equipment that require pelletized resin, the second reason is that TPS is difficult to mix with standard plastic materials such as High Density Polyethylene (HDPE). BiologiQ of Blackfoot Idaho through a unique manufacturing process has created a new type of TPS called EcoStarch™ Resin (ESR) that overcomes these two obstacles the material can be both pelletized and combined with various standard base plastics such as HDPE. This study evaluated and characterized the processability materials properties of ESR and HDPE blends in the Extrusion Blow Molding (EBM) by measuring wall thickness, tensile strength, tensile elongation, modulus of elongation and formability compared to 100% HDPE bottles. As the ESR content increased the uniformity of the wall thickness increased. The tensile strength increased from ESR content of 30% to 50% while the elongation decreased. Bottles were successfully extrusion blow molded with ESR content of 50%.

<p>Wireless communications and interconnected devices have become ubiquitous in our everyday life. As the rollout of the 5th generation (5G), wireless communication technology is well underway, the number of interconnected devices is increasing exponentially. Estimations for 2021 predicted that 1.5 billion smart devices would sell globally, representing a $53.45 billion market size by 2022. With the increase of communication channels and transmitted data within these networks, the challenge of coexistence without interference will become prominent. Simultaneously, 5G networks are introducing more frequency bands while densifying the network of communication towers. Forecasts predict a 100X increase of the network at the edge by introducing small cell towers, with projections estimating 45 million installed by 2031. As a result, rapid exponential growth in hardware costs is expected. Also, these dense networks will require a higher degree of self-configuration to prevent adjacent band interference.</p> <p>Tunable filters and large-scale manufacturing technologies are two solutions to address these challenges. Reconfigurable high-quality evanescent-mode (EVA) filters have been extensively presented in the literature. Different mechanisms have been employed for tuning, such as piezoelectric actuators and motors, and magnetostatic and electrostatic actuators. Furthermore, these implementations have been realized with printed circuit board (PCB) technology, computer numerical control (CNC) machining, 3D printing, and silicon (Si) micro-machining. Specifically, PCB manufacturing of three-dimensional front-end tunable filters has been promising and can deliver excellent performance. In addition, they can be integrated into the existing manufacturing lines and circuitry for the RF front-end.</p> <p>Nonetheless, there are limitations in fabrication tolerances that PCB manufacturing could reach. Consequently, there are restrictions on the frequency bands that these devices can be manufactured as dimensions become smaller in higher bands. Moreover, EVA cavities have been proven to yield higher performance filters when compared to unloaded quality factors and power handling of currently used substrate integrated waveguide (SIW) based technologies. Specifically, EVA filters produced with silicon micro-manufacturing combined with MEMS actuators have been demonstrated with remarkable performance up to 100s of GHz. Also, cost limitations per unit built are significant compared to other technologies like injection molding.</p> <p>The research goal of this work is to investigate scalable, low-cost manufacturing processes and techniques while maintaining a high-performance device. Combining knowledge from silicon RF MEMS tuned EVA filters and the cost-effective mass manufacturing injection molding technology to deliver a high-Q, high power handling, low-cost tunable filter. Demonstrating these characteristics within the same manufactured prototype would be a unique solution within the existing literature on tunable filters.</p> <p>This thesis is organized into three parts. The first part is focused on design for manufacturing (DFM). Si micromachining has been used to produce tunable resonators and filters at lower bands, but higher bands have yet to be demonstrated. The low-cost batch fabrication of already established Si micromachining lines makes this an attractive technology to realize these devices. This section presents network densification’s challenges and the economics of scale-up manufacturing. Furthermore, using Si micromachining, the first high Q tunable W band RF resonator is demonstrated tuned with MEMS technology.</p> <p>In the second part, the focus is on design for performance (DFP). Si micromachining is optimized to demonstrate high-performance RF MEMS tunable filters up to 100s GHz. High Q, wide tuning range, and low actuation voltages for the MEMS tuners have been realized.</p> <p>In the third part, the focus is on design for cost (DFC), where injection molding manufacturing technology is proven to have significant advantages in low cost with respect to other large-scale manufacturing technologies. A high-performance tunable resonator and filter in the sub-6 GHz frequency band are manufactured. They prove that simultaneously high Q, widely tunable, high power capable filters can be produced with low-cost scalable manufacturing technology.</p>

In this project, a stackable and foldable basket would be developed. The basket will be used for grocery shopping, where it can replace single use bags. Private individuals would own and use the basket for grocery shopping and grocery stores would use it for home deliveries. The project was divided into two phases. In the first phase, the research phase, relevant facts were gathered. A literature study focusing on sustainability was conducted as well as user studies. All information resulted in a number of insights that formed the basis for the coming phase. Some ofthe major insights were that people appreciate the feeling of ‘close to nature’ in relation to food and that shopping for food must not take up unnecessary time or be complicated. Also, it was realized that a basket intended for home delivery and a basket intended for private use would differ. Therefore, it was decided to focus on making a basket intended for private use. In the second phase, the design phase, a large number of ideas were generated. CAD, sketching and rapid prototyping were used as tools. Iterations resulted in four concepts of baskets. The baskets were folded in different ways and had different value-added functions. Prototypes were made and used during user tests, which resulted in no longer continuing to develop any type of value-added function. It was also decided to continue developing the concept of The straight collapsible basket. This basket was similar to a box in shape and would therefore, for practical reasons, also be well suited for home delivery. Likewise, with eliminated value-added functions, the basket would not risk becoming too complex. Therefore, home delivery was again included within the use of the basket. A detailed CAD model was made where the design was adapted tothe requirements of injection moulding. Likewise, the design and material were adapted to the mood board that had been developed. The material was also selected based on a smaller LCA, made in the GRANTA EduPack program. In parallel, solid mechanics calculations were made to ensure that the basket would meet the load capacity requirements. The result is a product proposition that meets the requirements of stackability and foldability. It is adapted for both private use and home delivery. / I detta projekt skulle en vikbar och stapelbar korg utvecklas. Korgens ska användas till mathandling, där den kan ersätta engångspåsar. Privatpersoner kan äga och använda korgen till mathandling och livsmedelsbutiker kan nyttja den vid hemleverans. Projektet var uppdelat i två faser. I den första fasen, researchfasen, samlades relevant fakta inom området. En litteraturstudie med fokus på hållbarhet gjordes och användarstudier utfördes. Informationen resulterade i ett antal insikter som låg till grund för den kommande fasen. Några av de större insikterna var att människor uppskattar känslan av naturnära i relation till mat och att mathandling inte får ta upp onödig tid eller vara krångligt. Framförallt insågs att skillnaderna mellan en korg ämnad för hemleverans och en korg ämnad för privat bruk skulle riskeras vara för stora. Därför beslutades det att fokusera på att göra en korg anpassad för privat bruk. I den andra fasen, designfasen, genererades ett stort antal idéer. CAD, skiss och rapid prototyping var verktyg som användes. Iterationer resulterade i fyra koncept, bestående av korgar. Korgarna fälldes ihop på olika sätt och hade olika mervärdesfunktioner. Prototyper av kartong gjordes som sedan användes vid användartester. Användartesterna resulterade i att inte längre fortsätta utveckla någon typ av mervärdesfunktion samt att fortsätta utveckla konceptet av The straight collapsible basket. Denna korg var lik en låda till formen och skulle därför av praktiska skäl lämpa sig bra även inom hemleverans. Likaså, med eliminerade mervärdesfunktioner skulle korgen inte riskera att bli komplex att hantera. Därför blev det aktuellt att åter inkludera hemleverans inom användandet av korgen. En detaljerad CAD-modell gjordes där designen anpassades efter de kravsom tillverkningstekniken formsprutning ställer. Likaså anpassades designen och materialet efter den mood board som tidigare tagits fram. Materialet valdes också baserat på en mindre LCA, gjord i programmet GRANTA EduPack. Parallellt gjordes hållfasthetsberäkningar för att säkerställa att korgen skulle möta de krav som hade satts gällande last. Resultatet är ett produktförslag som uppfyller kraven på stapel- och vikbarhet. Den är anpassad för både privat bruk och hemleverans.

Injection molded short fiber reinforced composites have generated commercial interest in the manufacturing of lightweight parts used in semi-structural applications. Predicting these materials’ fiber orientation with quantitative accuracy is crucial for technological advancement, but the task is difficult because of the effect of inter-particle interactions at high concentrations of fiber found in parts of commercial interest. A complete sample preparation procedure was developed to obtain optical micrographs with optimal definition of elliptical and non-elliptical footprint borders. Two novel aspects in this procedure were the use of tridimensional markers to identify specific locations for analysis and the use of controlled-etching to produce small shadows where fibers recede into the matrix. These images were used to measure fiber orientation with a customized image analysis tool. This tool contains several modifications that we introduced in the method of ellipses which allow us to determine tridimensional fiber orientation and to obtain measurements in regions with fast changes in orientation. The tool uses the location of the shadow to eliminate the ambiguity problem in orientation and characterizes non-elliptical footprints to obtain the orientation in small sampling areas. Cavitywise measurements in two thin center-gated disks showed the existence of an asymmetric profile of orientation at the gate and an orientation profile that washed out gradually at the entry region until disappearing at about 32 gap widths. This data was used to assess the prediction of cavitywise orientation using a delay model for fiber orientation with model parameters obtained from rheometrical experiments. Model predictions combining slip correction and experimentally determined orientation at the gate are in agreement with experimental data for the core layers near the end-of-fill region. Radialwise measurements of orientation at the shell, transition and core layer, and microtextural description of the advancing front are included in this dissertation. The analysis and assessment of the radial evolution of fiber orientation and advancing front based on comparing the experimental data with simulation results are under ongoing investigation. / Ph. D.

This investigation completed the verification of a three-dimensional resin transfer molding/resin film infusion (RTM/RFI) process simulation model. The model incorporates resin flow through an anisotropic carbon fiber preform, cure kinetics of the resin, and heat transfer within the preform/tool assembly. The computer model can predict the flow front location, resin pressure distribution, and thermal profiles in the modeled part. The formulation for the flow model is given using the finite element/control volume (FE/CV) technique based on Darcy's Law of creeping flow through a porous media. The FE/CV technique is a numerically efficient method for finding the flow front location and the fluid pressure. The heat transfer model is based on the three-dimensional, transient heat conduction equation, including heat generation. Boundary conditions include specified temperature and convection. The code was designed with a modular approach so the flow and/or the thermal module may be turned on or off as desired. Both models are solved sequentially in a quasi-steady state fashion. A mesh refinement study was completed on a one-element thick model to determine the recommended size of elements that would result in a converged model for a typical RFI analysis. Guidelines are established for checking the convergence of a model, and the recommended element sizes are listed. Several experiments were conducted and computer simulations of the experiments were run to verify the simulation model. Isothermal, non-reacting flow in a T-stiffened section was simulated to verify the flow module. Predicted infiltration times were within 12-20 percent of measured times. The predicted pressures were approximately 50 percent of the measured pressures. A study was performed to attempt to explain the difference in pressures. Non-isothermal experiments with a reactive resin were modeled to verify the thermal module and the resin model. Two panels were manufactured using the RFI process. One was a stepped panel and the other was a panel with two `T' stiffeners. The difference between the predicted infiltration times and the experimental times was 4 to 23 percent. / Master of Science

Bacteria are known to adhere to surfaces, which allows for the formation of biofilms, possibly causing a surge in hospital-offset infections, perilous diseases, and in some cases, death. Although certain bacteria are present in the natural flora of the human skin, some present extreme clinical significance due to the ability to transmit and adhere, and can be resistant to antibiotics. They also evolve over time to survive in harsh environmental conditions. Current research reveals that design of plastic surfaces containing submicron structures, is becoming a popular approach to tackle issues concerning infection transmission, with inspiration being derived from biomimetics and self-cleaning surfaces, such as the surface of a gecko skin, and the hydrophobic wax layer of forest leaves. Main barriers to adoption include that these surfaces alone are difficult to manufacture on 3D products, expensive to fabricate on a large scale and do not last long when subjected to environmental wear. Replication of nano-scale ridges was carried out using micro-injection, and the various samples were characterised using a range of tools to determine physical and biomechanical parameters. The sample surfaces were then cultured with the pathogenic bacterium Staphylococcus aureus under several environmental conditions, and the results were statistically analysed to reveal that anti-fouling LIPSS (laser induced periodic surface structures) ridges perform better to reduce bacteria cell-substrate adhesion, when compared to flat surfaces, or surfaces containing dual structures (anti-fouling ridges combined with anti-wear walls). It was therefore demonstrated that nanotextured polymeric surfaces with hydrophobic characteristics have exceptional non-fouling properties, preventing S. aureus, a very significant bacterial strain, from initial adhesion, a critical primary mechanism in its ability to proliferate. Collectively, the findings of this study strongly support the literature, suggesting that the bacteria struggle to adhere onto polymeric topography with increased water contact angles and simple nanostructures. However, the addition of certain anti-wear micro-features increased bacterial adhesion, reducing the efficacy of the non-fouling nanostructures from preventing biofilm formation.

Glass fiber based polymer composites based injection molded parts provide a light-weight high-strength alternative for use in automobile applications. These composites have enhanced mechanical properties compared to those of pure polymers, if the fibers are oriented in the right direction. One of the major challenges in processing of these composites is to control the fiber orientation in the final product. The evolution of short glass fiber orientation in a center-gated disk was experimentally determined along the radial direction at three different heights representative of the shell, transition and core layers, respectively. Orientation data along the shell and transition layers in the lubrication region show shear flow effects, which tends to align the fibers along the flow direction. In the core layer, where the extension in the "-direction dominates, fibers tend to get aligned along the "-direction. In the frontal flow region orientation in the flow direction drops in all three layers due to fountain flow effects. Fiber orientation predictions in coupled and decoupled transient simulations using the Folgar-Tucker model, and the two slow versions of the Folgar-Tucker model, namely the slip Folgar-Tucker model and the reduced strain closure (RSC) model were compared with the experimental data. Measured inlet orientation was used in all simulations and model parameters were determined by fitting model predictions to rheological data under startup of shear. Pseudo-concentration method was implemented for the modeling of the advancing front and fountain flow effects in the region near the front. Discontinuous Galerkin finite element method and a third order Runge-Kutta total variance diminishing time integration scheme were implemented for the solution of the orientation and transport equations. In the lubrication region of the shell layer, all three orientation models provided a good match with the experimental data. In the frontal region, fountain flow simulations showed characteristic features seen in r- and z-profiles of orientation, although the experimental data showed these features at a relatively larger distance behind the front while the simulations predicted these effects only up to a small distance behind the front. On the other hand, orientation predictions with the Hele-Shaw flow approximation showed significant over-predictions in the frontal region. With model parameters determined from fitting to rheological data, coupling did not show any significant improvements. However, with the use of a smaller value of the fiber interaction parameter, coupling showed significant improvement in orientation predictions in all three layers in the frontal region. The simulation scheme was extended to long fiber systems by comparing available long fiber orientation data in a center-gated disk with model predictions using the Bead-Rod model which considers fiber bending, a property exhibited by long semi-flexible fibers. The Bead-Rod model showed improvements over rigid fiber models in the lubrication region of the shell layer. However, close to the front, both models showed similar predictions. In fountain flow simulations, the flow features seen in the r- and z-profiles were much better predicted with both the models while Hele-Shaw flow approximation showed over-prediction of orientation in the flow direction, especially in the shell layer. / Ph. D.