53 documents found, page 1 of 6
From transparent to opaque: a route towards multifunctional parts injected with...
Pedroso, Luís D.; Pontes, A. J.; Alves, António; Duarte, F. M.; Carneiro, O. S.The technological, social and economic development observed in recent decades brought an exponential increase in consumption and inherent new challenges. Recycling is one of the best solutions to minimize the environmental impact of raw materials. However, multi-material components are difficult or even impossible to recycle. The present work focuses on the reduction in the number of different materials used in...
A numerical methodology to support the development of liquid adhesive spreading...
Bastos, Lourenço; Duarte, F. M.; Viana, J. C.; Silva, Filipe; Nogueira, Miguel; Carneiro, FilipaA numerical methodology was implemented to support the development of adhesive spreading patterns for the Optical Bonding (OB) material on display bonding process, in order to reduce the experimental trial and error effort, being this iterative process done mainly through numerical simulations. These simulations were performed using the commercial software Abaqus, more specifically the Abaqus/Explicit module, w...
Materials screening and characterization for functional printed automotive inte...
Hammes, Nathalia; Ribeiro, Carolina; Machado, Catarina; Ferreira, João; Campos, Ricardo Emanuel Ribeiro; Faye, Djibril; Cortez, Ana; Melo, SandraFlexible printed electronics (PE) has attracted strong interest during the last two decades and is one of the successful trends in material science, representing the future of PEs. This research work evaluates the use of screen-printing technology and materials for producing functional circuits for automotive interior parts, which can be subsequently processed through in-mold electronics (IME). Since the select...
Ergonomics applied to the development and evaluation of insoles for protective ...
Lima, Ana Lúcia Gadelha Moura; Costa, Susana Raquel Pinto; Costa, Nélson Bruno Martins Marques da; Leão, Celina Pinto; Moraes, Anna Sophia PiacenzaKnowledge of ergonomics/human factors plays an important role in the creation and design of safety shoes and insoles, contributing to worker protection, comfort, and stability. The purpose of this study is to compare previous insole designs and analyze the plantar pressure and gait pattern kinematics using the Oxford foot model protocol. The tests were performed comparing the environments on the three rockers o...
Transmission laser welding of thermoplastics: influence of welding parameters a...
Bastos, Lourenço; Alves, Marco; Sousa, Bruno; Vilela, Andreia; Rietter, Luciano; Duarte, F. M.; Carneiro, Filipa; Żmijewska-Rocha, AgnieszkaLaser transmission welding of injection moulded thermoplastics is commonly used in industrial applications such as electronic packaging, textiles, biomedical devices, windows, signs, food and medical packaging, visual displays and automotive components due to very precise control of the process parameters, including the amount of energy delivered and its location, which results in high joint quality. In this ar...
Predicting the effect of build orientation and process temperatures on the perf...
Duarte, F. M.; Covas, J. A.; Costa, Sidonie Fernandes daPurpose: The performance of the parts obtained by fused filament fabrication (FFF) is strongly dependent on the extent of bonding between adjacent filaments developing during the deposition stage. Bonding depends on the properties of the polymer material and is controlled by the temperature of the filaments when they come into contact, as well as by the time required for molecular diffusion. In turn, the temper...
Setting the optimal sheet thickness distribution for plastics thermoforming by ...
Gaspar-Cunha, A.; Galuppo, Wagner; Costa, Paulo; Nóbrega, J. M.; Duarte, F. M.; Costa, LinoThermoforming is a thermoplastic processing technique commonly used in the rigid packaging industry. The process comprises a heating stage, which aims at allowing the sheet to acquire the required deformability, a deformation stage, in which the sheets conform to the mould surface, and, finally, a cooling stage, which allows the part to be extracted from the mould without distorting. Since there are several pro...
Effect of polymer type on the properties of polypropylene composites with high ...
Marques, Mariana; Gonçalves, Luís Filipe Fernandes Ferreira; Martins, Carla I.; Vale, Mário; Duarte, F. M.The main focus of this work is to study the processability and characteristics of highly loaded spent coffee grounds (SCG) thermoplastic polymer composites, for sustainable applications. SCG powder was characterized in terms of size distribution, moisture, morphology and thermal stability. Polymer/SCG composites were prepared by extrusion compounding. Polypropylene (PP) homopolymer and copolymer were used as th...
Improving the thickness distribution of parts with hybrid thermoforming
Duarte, F. M.; Ribeiro, Catarina G.; Ferreira, João G.; Forte, Sílvia A.; Covas, J. A.With the aim of improving the thickness gradient of thermoformed parts, and thus increase their performance and/or reduce their weight, the concept of hybrid thermoforming is introduced, whereby local thickness differences in extruded sheets are created prior to thermoforming. Material is removed by CO2 ablation or 3D printing of an over-thickness at specific locations of sheets previously extruded. The feasibi...
A review on in-mold electronics technology
Beltrão, Mariana Martins; Duarte, F. M.; Viana, J. C.; Paulo, VitorIn Mold Decoration (IMD) with printed electronic films combines the printed functional film with the IMD process, creating a product with embedded electronic functions that requires much less space compared to previous technologies. In Mold Electronics (IME) is a process of integrating printed decorations and functional electronics with IMD (i.e., thermoforming and injection molding), resulting in 3D-shaped obj...