Diseño de Ayuda Técnica para Terapia Física Enfocada a Personas con Paraplejia: Revisión de la Literatura

La discapacidad de tipo motriz puede ser ocasionada por distintos factores y afectar a un número diferente de miembros del cuerpo, siendo la paraplejia la que origina la parálisis completa o parcial de las extremidades inferiores.  Las personas que sufren de paraplejia por su movilidad limitada tienen grandes riesgos en la salud, por lo que los ejercicios de rango de movimiento son muy importantes, los cuales pueden verse apoyados de ayudas técnicas y tecnologías de apoyo. La presente investigación surge de la necesidad de diseñar un producto que cumpla con los requerimientos de movilidad de miembros inferiores en personas con paraplejia, dentro de esta primera fase de estudio se realizó una revisión de la literatura, una revisión de patentes, búsqueda de equipos a la venta en el mercado y entrevistas al grupo de estudio y a especialistas en el área, esto con la finalidad de comprender y especificar el contexto de la investigación

Metodología de Diseño de Prendas Usando Textiles Impresos en 3D con Filamento PET Reciclado

El plástico es el material más frecuentemente encontrado a escala global en costas y ambientes marinos. Asimismo, los residuos sólidos representan una fuente de emisión y reproducción de vectores, con aportaciones a la contaminación atmosférica en entornos urbanos. Incorporar materia prima derivada de desechos plásticos a la cadena de suministro para generar productos de alto valor, como lo sugiere el concepto de economía circular, ayudaría a disminuir la contaminación. Una forma de lograrlo es a través de la implementación de tecnologías en crecimiento como la manufactura aditiva (MA), con la cual se pueden manufacturar productos atractivos, innovadores y personalizables. La industria textil representa un nicho de oportunidad para la implementación de estos materiales y tecnologías, a partir de la generación de prendas con alto valor ecológico y emocional. Por lo tanto, se propone una metodología donde la fase 1 y 2 involucran la primera etapa del diseño guiado por materiales (MDD), la fase 3 habla sobre la definición del usuario y prenda a diseñar y, finalmente, la fase 4 y 5 se centran en el modelo de procesos representativos para el desarrollo actual de prendas de vestir. Se concluye que la fabricación de productos con alto valor ecológico, a partir de residuos plásticos, es una opción viable y económicamente eficiente siempre y cuando el producto se diseñe pensando en todas sus fases de ciclo de vida, se conozca el material, su comportamiento y cómo el usuario lo percibe

Reduction of the Fused Filament Fabrication Process Time in the Manufacturing of Printed Circuit Board Slots

Fused Filament Fabrication is an Additive Manufacturing technology that is continuously improving its technologies. The present research exposes the use of the Travel Salesman Problem and Nearest Neighbor Algorithm as a strategy to reduce the time need to print slots shield in a Printed Circuit Board. The methodology used describes the process from the design to the printing board. A board of 98 slots of four geometries was analyzed. The results present a reduction of 5.88% of the original time required to print the board

Diseño axiomatico: Libro de fundamento y aplicaciones

https://dialnet.unirioja.es/descarga/libro/735059.pd

Genetic algorithm for the reduction printing time and dimensional precision improvement on 3D components printed by Fused Filament Fabrication

Additive manufacturing (AM) has managed to stand out globally, with a financial forecast growth of $26.28 billion by 2027, where$14.54 billion will be generated due to fused filament fabrication (FFF) technology. Despite this significant growth, researchers in the FFF field are working on solving problems associated with productivity and efficiency, where finishing components are one of the most critical aspects. This paper reports the implementation of a genetic algorithm (GA) to optimize the extruder path during the FFF process, comparing the results based on the dimensional finish of a printed component with the traditional method (CTRAD) with a printed component with the implementation of a GA that modifies the 3D printing path (CMOD). The methodology includes (1) FFF of the CTRAD and FFF of the CMOD and (2) measuring and comparing 118 dimensions associated with each attribute of CTRAD and CMOD using a coordinate measuring machine (CMM). Comparisons are made among the computer-aided design (CAD), the CTRAD, and the CMOD. Results show that 83.9% of the dimensions of the CTRAD components are different from the dimensions of the components defined in the CAD, and 81% of the dimensions of the CMOD components are different from the dimensions of the components defined in the CAD. Finally, 53% of the dimensions in the CTRAD are different from those in the CMOD. The implementation of the GA helps reduce the lead time of the subject of study by 11.2%, ensuring that the surface texture of CTRAD and CMOD has the same behavior and is greater than those defined in CAD design. Also, it is identified that there is no significant dimensional difference between the CTRAD and the CMOD

Jurnal Pengembangan Rekayasa dan Teknologi

Several reports have studied the mechanical properties of the material extrusion additive manufacturing process, specifically referred to as fusion deposition modeling (FDM) developed by Stratasys. As the applications for 3D printed parts continue to grow in diversity (e.g., gears, propellers, and bearings), the loading conditions applied to printed parts have become more complex, and the need for thorough characterization is now paramount for increased adoption of 3D printing. To broaden the understanding of torsional properties, this study focused on the shear strength of specimens to observe the impact from additive manufacturing. A full factorial (42) design of experiments was used, considering the orientation and the raster angle as factors. XYZ, YXZ, ZXY, and XZY levels were considered for the orientation parameter, as well as 0°, 45°, 90°, and 45°/45° for the raster angle parameter. Ultimate shear strength, 0.2% yield strength, shear modulus, and fracture strain were used as response variables to identify the most optimal build parameters. Additionally, stress-strain diagrams are presented to contrast elastic and plastic regions with traditional injection molding. Results demonstrated an interaction of factors in all mechanical measured variables whenever an orientation and a raster angle were applied. Compared to injection molding, FDM specimens were similar for all measured torsion variables except for the fracture strain; this led to the conclusion that the FDM process can fabricate components with similar elastic properties but with less ductility than injection molding. The orientation in YXZ with the raster angle at 00 resulted in the most suitable combination identified in the response optimization analysis

Comparación de polvos PA12 residuo de sinterizado láser selectivo con fines de reúso funcional

Actualmente, la poliamida 12 (PA12) es uno de los polímeros con mayor uso en la industria de la manufactura aditiva en sus diversas tecnologías. En el Sinterizado Láser Selectivo (SLS), la pureza del material permite obtener piezas de buena calidad, sin embargo, los usuarios prefieren disponerlo como desecho debido a que su integridad se degrada si se intenta el reúso. En el presente trabajo se reporta una comparación de polvos de PA12 virgen y residuo, analizando si existe algún cambio en sus características morfológicas, químicas y cristalinas. Para ello, se realizaron los análisis micrográfico por medio de SEM-EDS; estructural, de los grupos funcionales por FTIR; y cristalino, por medio de XRD. Como resultado, se obtuvo que el tamaño de partícula para la calidad residuo presenta mayores tamaños respecto al virgen. Los análisis de FTIR y XRD mostraron la presencia de los mismos grupos funcionales en la PA12 virgen y PA12 residuo, así como propiedades cristalinas similares en ambas sustancias. Se concluye con una recomendación para el reúso del polímero, considerando estrategias en cuanto al aumento de tamaño de la partícula

Ergonomics Implementation in Manufacturing Industries: Management Commitment for Financial Benefits

Ergonomics is a multidisciplinary science that seeks to adapt systems and products to human capacities and limitations. Therefore, Ergonomics leads to benefits in terms of health, quality of life, and safety, as well as to financial benefits. However, its implementation process is slow and complex as it takes effective analysis to determine critical factors for a successful implementation and the attainment of such benefits. This chapter offers an analysis by structural equations modeling to identify those critical success factors as well as the way they relate to financial benefits. Four stages in the implementation process were considered and a 114-item questionnaire was developed and validated for data collection within manufacturing companies. The questionnaire was administered to a sample of 139 individuals in middle and upper management positions, showing direct, indirect and total effects of Ergonomics implementation and the role of management commitment standing out as a critical factor to obtain financial benefits

Folding behavior of thermoplastic hinges fabricated with polymer extrusion additive manufacturing

Due to the layer-by-layer nature of additive manufacturing, fabricated parts suffer from an anisotropic behavior with reduced mechanical performance when compared to traditional manufacturing. One specific mechanical property, folding endurance, requires both low flexural strength and simultaneously high elongation to achieve the flexibility needed to sustain repetitive bending. The present work provides an analysis of selected thermoplastics’ flexural capacity, including nylon (PA), polyethylene terephthalate (PETG), polylactide (PLA), thermoplastic polyurethane (TPU), polypropylene (PP), polyethylene (PE), and a TPR blend (ABSMG94: SEBS-g-MA 25:75), in order to evaluate the maximum number of folding cycles and load capacity sustained by a living hinge. A fractographic analysis was performed using scanning electron microscopy and computed tomography. Similar to the performance of injected molded products, the experimental results demonstrated that three of the tested materials behaved well in the context of a large number of folding cycles prior to an eventual detachment into two pieces; TPR blend, 244,424 cycles; PP endured one million cycles; and TPU, more than two million cycles, while the remaining materials failed to survive more than 1000 cycles. The hinges failure analysis revealed a wide variety of fracture morphologies and failure modes. In regard to the load capacity, PLA, PETG, and nylon provided the highest results in the ultimate strength of an axial static force applied (790.61 N, 656.06 N, and 652.75 N respectively), while the TPR blend was the highest (398.44 N) of the elastomeric materials (PP, TPU, and TPR blend). The evaluated materials demonstrated enough flexibility for use in specific applications such as stretchable electronics and wearable applications