Este trabalho analisou o processo de moldagem por injeção de micro elementos ópticos difrativos usinados em insertos de cobre eletrolítico com ferramenta de diamante com ponta única. Quatro tipos de microestruturas características foram selecionados neste estudo, a saber: lente anesférica, lente de Fresnel, grade de difração (blaze grating) e sensor de frente de onda. A análise da fidelidade de replicação foi feita considerando aspectos dimensionais micrométricos e nanométricos para a microestrutura e acabamento. Um perfilometro óptico e microscópio eletrônico de varredura foram utilizados para avaliar os insertos usinados e as características dos replicados. Uma ferramenta de diamante com geometria especial, com meio raio, foi usada para usinar as características de difração. As superfícies usinadas apresentaram baixo acabamento superficial, na faixa de 16 nm Rms. As simulações numéricas foram realizadas para avaliar o desempenho do processo de moldagem por injeção com polimetilmetacrilato (PMMA), e os resultados foram utilizados para orientar a injeção do polímero. Com base na simulações numéricas as temperaturas do molde e pressões de injeção foram variadas entre 85ºC/130°C e 70 bar/130 bar, respectivamente. A influência destes parâmetros no desempenho do processo de replicação foi analisada. A análise quantitativa da replicação foi feita através de um parâmetro denominado grau de replicação que define a relação entre a altura nominal da microestrutura do inserto e à altura da microestrutura na réplica de polímero. A grade de difração e o sensor de frente de onda apresentaram os melhores níveis de replicação: 98% e 99%, respectivamente. Os resultados experimentais mostraram que o processo de moldagem por injeção é uma técnica viável para replicar com alta qualidade microcaracterísticas de elementos ópticos de difração gerados por torneamento com ferramenta de diamante com ponta única. / This work investigated the injection molding process of micro diffractive optical elements machined on electrolytic copper inserts by single point diamond turning. Four types of microstructure features were selected in this study, namely: aspherical lens, Fresnel lens, blaze grating and the wavefront sensor. The replication fidelity was evaluated in terms of dimensional micrometric features found in the microstructure and the surface finish. An optical profiler and scanning electron microscopy were used to assess the machined inserts and the replicated features. A special geometry diamond tool with half radius was used to machine the diffraction features. The machined surfaces presented very low surface finish in the range of 16 nm Rms. Numerical simulations were carried out to evaluate the performance of the injection molding process with polymethylmethacrylate (PMMA), and the results were used to guide the polymer injection. Based on numerical simulations mold temperatures and injection pressures were varied between 85°C/130°C and 70 bar/130 bar, respectively. The influence of these parameters on performance of the replication process was assessed. The quantitative assessement of the replication was made by using a parameter called degree of replication which defines the ratio between the nominal height of the microstructure in the insert and the height of the microstructure in the polymer replica. The blaze grating and the wavefront sensor presented the best degrees of replication: 98% and 99%, respectively. The experimental results showed that injection molding process is a viable technique to replicate high quality micro features of optical diffraction elements generated by single point diamond turning.

Yes / A novel process chain for serial production of polymer-based devices incorporating both micro- and nano-scale features is proposed. The process chain is enabled by the use of Zr-based bulk metallic glasses (BMG) to achieve the necessary level of compatibility and complementarity between its component technologies. It integrates two different technologies, namely laser ablation and focused ion beam (FIB) milling for micro-structuring and sub-micron patterning, respectively, thus to fabricate inserts incorporating different length scale functional features. Two alternative laser sources, namely nano-second (NS) and pico-second (PS) lasers, were considered as potential candidates for the first step in this master-making process chain. The capabilities of the component technologies together with some issues associated with their integration were studied. To validate the replication performance of the produced masters, a Zr-based BMG insert was used to produce a small batch of micro-fluidic devices by micro-injection moulding. Furthermore, an experimental study was also carried out to determine whether it would be possible by NS laser ablation to structure the Zr-based BMG workpieces with a high surface integrity whilst retaining the BMG's non-crystalline morphology. Collectively, it was demonstrated that the proposed process chain could be a viable fabrication route for mass production of polymer devices incorporating different length scale features.

Factory shop floors of the future will see a significant increase in interconnected devices for monitoring and control. However, if a Service Orientated Architecture (SOA) is implemented on all such devices then this will result in a large number of permutations of services and composite services. These services combined with other business level components can pose a huge challenge to manage as it is often difficult to keep an overview of all the devices, equipment and services. This thesis proposes an SOA based novel assimilation architecture for integrating disparate industrial hardware based processes and business processes of an enterprise in particular the plastics machinery environment. The key benefits of the proposed architecture are the reduction of complexity when integrating disparate hardware platforms; managing the associated services as well as allowing the Micro Injection Moulding (µIM) process to be monitored on the web through service and data integration. An Enterprise Service Bus (ESB) based middleware layer integrates the Wireless Sensor Network (WSN) based environmental and simulated machine process systems with frontend Google Gadgets (GGs) based web visualisation applications. A business process framework is proposed to manage and orchestrate the resulting services from the architecture. Results from the analysis of the WSN kits in terms of their usability and reliability showed that the Jennic WSN was easy to setup and had a reliable communication link in the polymer industrial environment with the PER being below 0.5%. The prototype Jennic WSN based µIM process monitoring system had limitations when monitoring high-resolution machine data, therefore a novel hybrid integration architecture was proposed. The assimilation architecture was implemented on a distributed server based test bed. Results from test scenarios showed that the architecture was highly scalable and could potentially allow a large number of disparate sensor based hardware systems and services to be hosted, managed, visualised and linked to form a cohesive business process.

Factory shop floors of the future will see a significant increase in interconnected devices for monitoring and control. However, if a Service Orientated Architecture (SOA) is implemented on all such devices then this will result in a large number of permutations of services and composite services. These services combined with other business level components can pose a huge challenge to manage as it is often difficult to keep an overview of all the devices, equipment and services. This thesis proposes an SOA based novel assimilation architecture for integrating disparate industrial hardware based processes and business processes of an enterprise in particular the plastics machinery environment. The key benefits of the proposed architecture are the reduction of complexity when integrating disparate hardware platforms; managing the associated services as well as allowing the Micro Injection Moulding (µIM) process to be monitored on the web through service and data integration. An Enterprise Service Bus (ESB) based middleware layer integrates the Wireless Sensor Network (WSN) based environmental and simulated machine process systems with frontend Google Gadgets (GGs) based web visualisation applications. A business process framework is proposed to manage and orchestrate the resulting services from the architecture. Results from the analysis of the WSN kits in terms of their usability and reliability showed that the Jennic WSN was easy to setup and had a reliable communication link in the polymer industrial environment with the PER being below 0.5%. The prototype Jennic WSN based µIM process monitoring system had limitations when monitoring high-resolution machine data, therefore a novel hybrid integration architecture was proposed. The assimilation architecture was implemented on a distributed server based test bed. Results from test scenarios showed that the architecture was highly scalable and could potentially allow a large number of disparate sensor based hardware systems and services to be hosted, managed, visualised and linked to form a cohesive business process.

No description available.

No / The advances of the polymer melt flow-induced crystallization behaviour and its influence on mechanical properties of high density polyethylene (HDPE) in micron injection (MI) were studied in the present paper. Analysis of mechanical performance, including yield stress and elongation at break, for samples adopted from different regions in a molded plaque showed that a higher injection speed, a higher mold temperature and a longer cooling time could effectively enhance the yield stress but negatively promoted the ductility. Then, the mechanisms of such variation of mechanical performance and the factors affecting it were investigated by means of differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and polarized light microscopy (PLM). The super high shear rate during cavity feeding in MI molding not only induced a typical three-layered structure but also developed a highly oriented fibrously morphological structure in the skin layer. However, such fully oriented morphology was much negative in the interlayer and even could not be observed in the core layer. The results from SEM and PLM observations indicated that the orientation morphology varied significantly through the plaque's cross-section and thickness of the each layer changed with the process parameters and geometric position, and finally led to variation of the mechanical performance.

No description available.