28 documents found, page 1 of 3
Development of a rapid heat cycle injection molding system using infrared radia...
Simoes, Ricardo; Macedo, Cláudia; Laranjeira, Jorge; Brito, A.M.; Simões, C.L.; Faria, L.Conventional injection molding is widely used to produce plastic parts, mainly in the automotive industry, due to the high production ratios and quality of injection parts. Low mold temperatures are usually employed to decrease cycle molding time and final process costs; however, resulting surface defects include weld lines, sink marks, and warpage. Therefore, plastic parts are often subjected to secondary proc...
Circularity Micro-Indicators for Plastic Packaging and Their Relation to Circul...
Matos, Joana; Martins, C.I.; Simoes, RicardoAbstract: Plastic packaging, in the form of films, brought several advantages to the commercialization of products given its lightness and durability. It provided better ergonomics, ease of transport, increased shelf life, and easy handling and use. Despite that, plastic packaging is facing enormous sustainability concerns associated with the traditional practice of linear economy, combined with commonplace irr...
Optimization of municipal solid waste collection system: systematic review with...
Neto, Alice; Simões, C.L.; Simoes, RicardoMunicipal solid waste management (MSWM) requires significant planning and objective definitions of each of its stages. Waste collection and transportation stages are of utmost importance, and they represent a significant cost of the process. In this context, a systematic study using bibliometric analysis was conducted, seeking to identify and understand the applied methodologies and tools, as well as which para...
Microcapsules of Poly(butylene adipate-co-terephthalate) (PBAT) Loaded with Ali...
Aguiar, A; Marcelino, L.P.; Mariquito, A; Simões, C.L.; Simoes, Ricardo; Pinho, Isabel; Marques, AThiswork introduces theencapsulationofhexamethylenediisocyanatederivatives(HDI,TriHDI, andPHDI)with thebiodegradablepolymerpoly(butyleneadipate-co-terephthalate) (PBAT) through a solvent evaporationmethod. Thesemicrocapsules(MCs)werethenemployedinadhesiveformulations for footwear.Moreover,MCs containingPHDIwereproduced ina closed vessel, demonstrating the potential for recovering and reusingorganicsolventsforth...
Comparative analysis of micro level indicators for evaluating the progress towa...
Matos, J; Martins, C; Simões, C. L.; Simoes, RicardoWith the transition from a linear to a more circular economic model, tools are required to monitor the effect of adopted changes, and to assist in further decision-making along time. Within this context, circularity micro-indicators have been proposed by many authors as a fairly simple tool to measure progress towards a more circular economy, at the product or company level. However, these circularity micro-ind...
The potential of RHCM technology in injection molding using a simple convention...
Macedo, Claudia; Brito, A.M.; Faria, Luis; Simões, Carla L.; Laranjeira, Jorge; Simoes, RicardoIn conventional injection molding, low mold temperatures are used; however, the thermal conditions, which vary during the processing, affect the properties of the injection molded parts and the injection molding process parameters. Due to the rapid cooling of the molten polymer against the mold wall, the flow resistance of the molten polymer increases, and the hydraulic injection pressure is directly affected b...
Environmental Assessment of the Valorization of Woody Biomass Residues: A Case ...
Simões, Carla L.; Simoes, Ricardo; Gonçalves, A. S.; Nunes, LeonelEvaluating Global Warming Potential (GWP) in waste management scenarios is crucial, especially in light of the escalating global concern for climate change and the pivotal role that waste management plays in mitigating this crisis. This research examines the GWP of three distinct waste management scenarios, each with a unique approach: (1) open burning, a method involving direct combustion with a GWP of 1600.1 ...
Integrative simulation chain for improved components design: linking mould fill...
Barbosa, Carlos; Viana, Julio; Franzen, Markus; Baranowski, Thomas; Simoes, RicardoComputer-Aided Engineering (CAE) is currently a standard tool in the development process of automotive components. For thermoplastic parts, for example, the manufacturing process is usually simulated with injection moulding simulation software, whereas passive safety is simulated with explicit crash software. Today, these two computational methods are only linked in the simulation of fibre-reinforced thermoplas...
Scratch behavior of reinforced HDPE through molecular dynamics simulations
Simoes, Ricardo; Oliveira, Marta; Yao, Jocelyn; Tian, Chris; Mirkhalaf, S.M.; Brostow, WitoldTo better understand the tribological behavior of polymer-based materials under scratching, we studied the effect of including a second phase in the form of liquid-crystalline (LC) islands in an amorphous matrix emulating high-density polyethylene. We employ molecular dynamics computer simulations with a coarse-grain model. The effects of the indenter diameter and force magnitude on the tribological properties ...
Optimization of a Microfluidic Process to Encapsulate Isocyanate for Autoreacti...
Costa, Mariana; Pinho, Isabel; Loureiro, Monica; Marques, Ana; Simões, Carla; Simoes, RicardoThe present paper reports a continuous microfluidic approach for the preparation of microcapsules (MCs), by interfacial polymerization, with a polyurea/polyurethane (PUa/PU) shell containing isophorone diisocyanate (IPDI). The microfluidic system enables the formation of a monodisperse oil-in-water (O/W) emulsion by a separate flow of the reagents along the tubing system, which posteriorly meet at a cross-junct...