10 documents found, page 1 of 1
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...
C60+C60 molecular bonding revisited and expanded
Laranjeira, Jorge; Strutyński, Karol; Marques, Leonel; Martínez-Núñez, Emilio; Melle-Franco, ManuelSeveral dimerization products of fullerene C60 are presented and thoroughly characterized with a quantum chemical DFT model augmented by dispersion. We reanalyze and expand significantly the number of known dimers from 12 to 41. Many of the novel bonding schemes were found by analyzing more than 2 ns of high energy molecular dynamics semiempirical trajectories with AutoMeKin, a methodology previously used to co...
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...
Instrumentation and In-mould data acquisition system for injection moulding pro...
Bernardo, Rodrigo M. C.; Zhiltsova, Tatiana; Oliveira, Mónica S. A.; Neto, Victor; Caseiro, João; Laranjeira, Jorge; Andrade-Campos, AntónioDeveloping new tools for industry that lead to a sustainable development is essential. This paper briefly presents the challenges the injection moulding industry faces in manufacturing plastic products and the requirement for moulds to possess specific characteristics to withstand the high pressures and thermal loads imposed on them. Over-sizing moulds to meet these requirements results in elevated production, ...
Instrumentation and In-mould Data Acquisition System for Injection Moulding Pro...
Bernardo, Rodrigo M. C.; Zhiltsova, Tatiana; Oliveira, Mónica S. A.; Neto, Victor; Caseiro, João; Laranjeira, Jorge; Andrade-Campos, AntónioDeveloping new tools for industry that lead to a sustainable development is essential. This paper briefly presents the challenges the injection moulding industry faces in manufacturing plastic products and the requirement for moulds to possess specific characteristics to withstand the high pressures and thermal loads imposed on them. Over-sizing moulds to meet these requirements results in elevated production, ...
Superconductivity in the Doped Polymerized Fullerite Clathrate from First Princ...
Laranjeira, Jorge; Errea, Ion; Dangić, Đorđe; Marques, Leonel; Melle-Franco, Manuel; Strutyński, KarolSuperconductivity in the new polymerized C60 fullerite clathrate doped with simple metals is investigated through density functional theory methods. The phonon dispersion curves are systematically computed for the clathrate structures containing the guest dopants (Li, Na, K, Be, Mg, Ca, Al, Ga, Ge) in one of the two distinct cages, fullerene-like C60 and sodalite-like C24, exhibited by this structure. Only four...
Clathrate structure of polymerized fullerite C60
Laranjeira, Jorge; Marques, Leonel; Melle-Franco, Manuel; Strutyński, Karol; Barroso, ManuelInvestigations of clathrate structures have gained a new impetus with the recent discovery of room-temperature superconductivity in metal hydrides. Here we report the finding, through density functional theory calculations, of a clathrate phase in the fullerite C60 system. Intermolecular bonds of the type 5/5 2+3 cycloaddition are induced between each C60 molecule and its twelve nearest neighbors in the face ce...
Modular data acquisition architecture for thin-film sensors surfaces
Rodrigues, Nelson; Lima, José; Rodrigues, Pedro João; Carvalho, José Augusto; Laranjeira, Jorge; Maidana, Wellington; Leitão, PauloThin-film sensors surfaces are becoming popular to collect data in several specific and complex processes, namely plastic injection or metal stamping, allowing the digitization of such processes through the use of Internet of Things technologies. A particular challenge in such thin-film sensors surfaces is the data acquisition and signal conditioning system, which implementation is complex due to the characteri...
Fabrication, characterization and implementation of thermo resistive TiCu(N,O) ...
Oliveira, Eva; Silva, João Paulo; Laranjeira, Jorge; Macedo, Francisco; Lanceros-Méndez, S.; Vaz, F.; Ferreira, ArmandoThis paper presents the development of metallic thermoresistive thin film, providing an innovative solution to dynamically control the temperature during the injection molding process of polymeric parts. The general idea was to tailor the signal response of the nitrogen- and oxygen-doped titanium-copper thin film (TiCu(N,O))-based transducers, in order to optimize their use in temperature sensor devices. The re...
C60 structures: structural, electronic and elastic properties
Laranjeira, Jorge; Marques, LeonelA systematic investigation, using density functional theory (DFT) methods, of the physical properties of onedimensional (1D), two-dimensional (2D) and three-dimensional (3D) pressure-induced polymerized C60 structures, was performed. The optimized crystal structures, the electronic density of states (DOS) and the bulk moduli B0 were calculated for such polymerized structures, showing how these properties change...