Product design of novel technology-based products - The importance of users

Terms such as product design, engineering design, and others, have been used to represent specific ways to look at Product Design and Development (PDD). Each of them features specific methods and techniques and, despite the evolution of PDD, most processes remain unchanged. Moreover, as products incorporate more technology, with emphasis on microelectronics, it becomes obvious that improvements of the traditional PDD processes are required. Incorporating microelectronics in products, without the user being able to perceive them, while simultaneously ensuring their functionality, is not a trivial task. Therefore, improving a user-centered design (UCD) approach is paramount. In this framework, 6 design processes proposed by different authors and the UCD standard were analysed by comparing the phases of each process, and their methods, techniques, and tools were explored. Finally, a case-study is described, which enables studying how the different processes can be applied and, how the user could be linked to the process. This opens the path for the optimization of PDD to meet the needs of novel products by improving the importance of users' direct participation in the process.- (undefined

Design of nozzles for surface mount technologies produced by additive manufacturing

The increasing use and production of electronic systems, equipped with multiple PCBs, leads to constant development in manufacturing technologies. A predominant choice in PCB production is Surface Mount Technology (SMT). The most important phase of the SMT process is the pickup and placement step, where nozzles, specific to the electronic component, are responsible to pick components and place them on the PCB. The interaction between the nozzles and the components imposes issues that lead to losses of process productivity. Currently, the development of a nozzle for an electrical component is time-consuming and, sometimes, the final solution is not tailored enough to take full advantage of the SMT machine efficiency. This research aims to fill this gap, through a new nozzle production method using additive manufacturing (AM), which makes it possible to respond to requirements such as, real-time, customized, and high dimensional accuracy nozzle design and production. Despite these advantages, the materials and manufacturing technologies available need improvements to meet the SMT requirements for nozzles production. Therefore, the research focused on the development of an electrostatic discharge (ESD) solution for AM, and the study of geometries that allow vacuum picking of electronic components with zero or low leakage. To show the viability of this method, electrical characterization tests were performed on the materials used, showing that ESD properties could be achieved. Moreover, a set of experimental tests were also performed to prove that the vacuum values were in the same range as the traditional nozzles. In sum, this research presents an alternative solution that allows for quick and flexible nozzle production.- (undefined

Evaluation of active heat sinks design under forced convection—effect of geometric and boundary parameters

This study shows the performance of heat sinks (HS) with different designs under forced convection, varying geometric and boundary parameters, via computational fluid dynamics simulations. Initially, a complete and detailed analysis of the thermal performance of various conventional HS designs was taken. Afterwards, HS designs were modified following some additive manufacturing approaches. The HS performance was compared by measuring their temperatures and pressure drop after 15 s. Smaller diameters/thicknesses and larger fins/pins spacing provided better results. For fins HS, the use of radial fins, with an inverted trapezoidal shape and with larger holes was advantageous. Regarding pins HS, the best option contemplated circular pins in combination with frontal holes in their structure. Additionally, lattice HS, only possible to be produced by additive manufacturing, was also studied. Lower temperatures were obtained with a hexagon unit cell. Lastly, a comparison between the best HS in each category showed a lower thermal resistance for lattice HS. Despite the increase of at least 38% in pressure drop, a consequence of its frontal area, the temperature was 26% and 56% lower when compared to conventional pins and fins HS, respectively, and 9% and 28% lower when compared to the best pins and best fins of this study.This research was funded by Portuguese Fundação para a Ciência e a Tecnologia (FCT), for financial support under the PhD scholarship SFRH/BD/144590/2019 and by European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 039334; Funding Reference: POCI-01- 0247-FEDER-039334]

Composite materials with MWCNT processed by Selective Laser Sintering for electrostatic discharge applications

Selective Laser Sintering (SLS) is an additive manufacturing technology that enables the production of polymeric parts for end-use applications. Despite the great potential of conventional materials, carbon-based reinforcements have been widely considered to contradict the electrically insulating nature of polymers, allowing the applicability of SLS in novel applications within electronics industry. However, the laser-sintering processing of such materials still encompasses a number of limitations including agglomeration problems, weak interparticle adhesion, low parts resolution, high processing time and costs. Therefore, this research reports the development of functional composite materials for SLS capable of being considered for the production of components that are in direct contact with electrostatic discharge (ESD) sensitive devices. To do so, composite materials of Polyamide 12 incorporating 0.50 wt%, 1.75 wt% and 3.00 wt% of Multi-Walled Carbon Nanotubes were developed aiming to achieve values of surface resistance between 104 - 109 Ω, according to the delivery instructions of Bosch Car Multimedia S.A. Test specimens produced by SLS were dimensionally, mechanically, electrically, thermally and morphologically characterized. Comparing to the neat matrix, the composite materials revealed narrower SLS processing window, reduced mechanical strength, surface resistance in the ESD range and electrical conductivity until 10−6 S/cm. Fundamentals on the sintering process of these functional materials are also provided.This work was co-funded by the European Regional Development Fund through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 47108, “SIFA”; Funding Reference: POCI-01-0247-FEDER-047108] and by the Foundation for Science and Technology (FCT) through the PhD scholarship 2020.04520.BD

The influence of the energy density on dimensional, geometric, mechanical and morphological properties of SLS parts produced with single and multiple exposure types

Selective Laser Sintering (SLS) is a Powder Bed Fusion technology that embraces a large number of variables influencing the properties of the parts produced. The well-known dependence and complex interaction established between the main process parameters demands continuous empirical research for effective SLS monitoring. The assessment of the energy density supplied by the laser beam to the powder bed during the process, that depends on the combination of the laser power, hatch distance, scan speed and layer thickness, is frequently considered for that purpose. Therefore, this research intends to evaluate the influence of the energy density on the dimensional, geometric, mechanical and morphological properties of SLS parts produced with conventional Polyamide 12 material. In this study, we considered different hatching and contour parameters in the energy range between 0.158 J/mm3 and 0.398 J/mm3 through single and multiple exposure types defining individual and combined parameterization sets, respectively. Results from X-ray computed tomography, tensile tests and scanning electron microscopy show that the implementation of a skin/core configuration allows the production of SLS parts with a valuable set of properties, minimizing the trade-off between mechanical strength and overall accuracy.This work was co-funded by the European Regional Development Fund through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 47108, “SIFA”; Funding Reference: POCI-01-0247-FEDER-047108] and by the Foundation for Science and Technology (FCT) through the PhD scholarship 2020.04520.BD

Development and characterization of composite materials with multi-walled carbon nanotubes and graphene nanoplatelets for powder bed fusion

Purpose: With the technological progress, high-performance materials are emerging in the market of additive manufacturing to comply with the advanced requirements demanded for technical applications. In selective laser sintering (SLS), innovative powder materials integrating conductive reinforcements are attracting much interest within academic and industrial communities as promising alternatives to common engineering thermoplastics. However, the practical implementation of functional materials is limited by the extensive list of conditions required for a successful laser-sintering process, related to the morphology, powder size and shape, heat resistance, melt viscosity and others. The purpose of this study is to explore composite materials of polyamide 12 (PA12) incorporating multi-walled carbon nanotubes (MWCNT) and graphene nanoplatelets (GNP), aiming to understand their suitability for advanced SLS applications. Design/methodology/approach: PA12-MWCNT and PA12-GNP materials were blended through a pre-optimized process of mechanical mixing with various percentages of reinforcement between 0.50 wt.% and 3.00 wt.% and processed by SLS with appropriate volume energy density. Several test specimens were produced and characterized with regard to processability, thermal, mechanical, electrical and morphological properties. Finally, a comparative analysis of the performance of both carbon-based materials was performed. Findings: The results of this research demonstrated easier processability and higher tensile strength and impact resistance for composites incorporating MWCNT but higher tensile elastic modulus, compressive strength and microstructural homogeneity for GNP-based materials. Despite the decrease in mechanical properties, valuable results of electrical conductivity were obtained with both carbon solutions until 10–6 S/cm. Originality/value– The carbon-based composites developed in this research allow for the expansion of the applicability of laser-sintered parts to advanced f ields, including electronics-related industries that require functional materials capable of protecting sensitive devices against electrostaticdischarge.FCT - Fundação para a Ciência e a Tecnologia(2020.04520

Engenharia e design - aditivo, contra o COVID-19

[Excerto] À medida que muitos de nós nos adaptamos a novas rotinas e tomamos precauções adicionais para cuidar da saúde e do bem-estar das nossas famílias e colegas, fomos ficando familiarizados com a natureza crescente da crise do coronavírus. “Confinamento”, “distanciamento social”, “estado de emergência nacional” foram termos que começaram a fazer parte do nosso dia-a-dia pela forma como vieram alterar os nossos hábitos diários. Já passaram quatro meses de uma nova realidade que diminuiu drasticamente a nossa mobilidade e nos colocou num estado de inércia, nunca antes vist

Design and industrial implementation of a multi-functional part produced by powder bed fusion

The use of robot end-effectors programmed to perform handling tasks in industrial environments has expanded in several sectors as a consequence of the rapid digital transformation seen in recent years. With such growing demands, additive manufacturing is evolving in the robotics field with more efficient, innovative, and customer-specific solutions owing to its design flexibility. Thus, this work presents a robot end-effector developed and produced by powder bed fusion (PBF) to execute palletizing operations in the automotive electronics industry, where electrostatic discharge interference is a critical concern. To guarantee the functionality of the developed robot end-effector under real conditions of implementation, prototypes of polyamide 12 (PA12) and PA12 incorporating graphene nanoplatelets were fabricated and characterized. This included the assessment of the mass, electrical surface resistance, and mechanical properties under tensile and compressive loads using biaxial strain gauges coupled to the prototypes for local strain monitoring. The experimental data were then used to define multilinear isotropic hardening models needed to numerically characterize the robotic system. At last, the final product was validated in an industrial environment at Bosch Car Multimedia S.A. Through the applied methodology, valuable insights in guiding process parameters optimization and materials selection for functional PBF parts depending on the technical requirements demanded by industrials are provided.FCT - Fundação para a Ciência e a Tecnologia(2020.04520) / Foundation for Science and Technology (FCT) through the PhD scholarship 2020.04520.BD.European Regional Development Fund through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 47108“SIFA”; Funding Reference: POCI-01-0247-FEDER-04710

Prediction of SLS parts properties using reprocessing powder

Purpose: Owing to the operating principle of powder bed fusion processes, selective laser sintering (SLS) requires effective management of the mixture ratio of processed material previously exposed to the high temperatures of processing with new virgin material. Therefore, this paper aims to fully understand the effect that the successive reprocessing has in the powder material and to evaluate its influence on the properties of SLS parts produced at different building orientations. Design/methodology/approach: Polyamide 12 material with 0%, 30% and 50% of virgin powder and parts produced from them were studied through five consecutive building cycles and their mass, mechanical, thermal and microstructural properties were evaluated. Then, the experimental data was used to validate a theoretical algorithm of prediction capable to define the minimum amount of virgin powder to be added on the processed material to produce parts without significant loss of properties. Findings: Material degradation during SLS influences the mass and mechanical properties of the parts, exhibiting an exponential decay property loss until 50% of the initial values. The theoretical algorithms of reprocessing proved the appropriateness to use a mixture of 30% of virgin with 70% of processed material for the most common purposes. Practical implications: This paper validates a methodology to define the minimum amount of virgin material capable to fulfil the operational specifications of SLS parts as a function of the number of building cycles, depending on the requirements of the final application. Originality/value: The use of theoretical models of prediction allows to describe the degradation effects of SLS materials during the sintering, ensuring the sustainable management of the processed powder and the economic viability of the process.The authors acknowledge the financial support given by FCT – Portuguese Foundation for Science and Technology through the reference project UID/CTM/50025/2019 and the European Structural and Investment Funds in the FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project n0 037902; Funding Reference: POCI-01-0247-FEDER-037902]

bridging the gap between quality and adaptability

© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis GroupOperational Excellence (OpEx) is understood by the quest to continuously improve performance. While used by organizations worldwide, the capacity of OpEx programmes to make organizations successful in unstable business environments has been challenged. This article aims to answer the research question of what the nature of the relationship between OpEx and Organizational Agility truly is. The authors have previously proposed a theoretical framework supporting the link between Operational Excellence, Organizational Culture, and Organizational Agility. While built on a strong conceptual background, this framework lacked empirical validation. Following the conclusion of ten industrial case studies, this article provides a summary of the key findings obtained in each case and integrates them into an updated conceptual model. As key findings, this study shows how Operational Excellence enablers and cultural orientation have an important role in the development and scaling up of Organizational Agility capabilities, highlighting how different contexts may influence these dynamics. This article offers a better understanding of the balance needed to maintain high operational performance levels while dealing with change. It connects and upholds the importance of Organizational Agility and of the cultural paradigm in the management of Quality in technical and technological organizations.publishersversionpublishe