Powder-binder separation in injection moulded green parts

For powder injection moulding (PIM) the ceramic powder is mixed with a thermoplastic binder system to achieve an injectable feedstock. In contrast to injection moulding of polymeric components, the binder must be removed after the shaping step before sintering the ceramic part to full density. During the mould filling process shear forces act on the blend that might cause separations of powder particles and binder. In this case polymer films form at the mould surface and at internal interfaces which induce microstructural defects in the debinded part. In particular for multi-component parts this effect is critical since binder films in the joining zone weaken the bonding strength between the two components that might even lead to delamination. For detecting binder separations within the injection moulded bulk material and at joining zones of two-component parts the microstructure of green samples has been studied. Since conventional machining techniques like grinding and polishing modify the original structure, e.g. when particles are pulled out of the matrix and binder smears onto the surface, a special ceramographic method for the preparation of cross-sections was applied. This approach bases on broad ion beam techniques and enables the simultaneous polishing of hard ceramic particles and soft polymer molecules without destroying the structure or producing a relief at the surface. In the analysed samples binder accumulations were found along flow lines, at weld lines, at boundaries of so-called dead water regions and at the interface of two-component parts

In Hulsmann, S.; Jampani, Mahesh (Eds.). A nexus approach for sustainable development: integrated resources management in resilient cities and multifunctional land-use systems. Cham, Switzerland: Springer

The Nexus Approach to environmental resources management is increasingly recognized as an important vehicle to achieve sustainability as spelled out in the Sustainable Development Goals (SDGs). In particular, it was argued that the Nexus Approach is key for the sustainable use of environmental resources under conditions of global change and provides a tool to deal with challenges of global change including climate change, urbanization and population growth. Building on conceptual considerations with regard to monitoring and implementation outlined earlier, here, we explore how the Nexus Approach may provide solutions for managing resources in multifunctional land-use systems and resilient cities. In fact, the resources perspective is essential for holistic management of water, soil and waste along the urban–rural axis. Peri-urban areas provide perfect examples of multifunctional systems with manyfold opportunities to closing cycles, improve resource efficiency and mitigate trade-offs. Cases described in this book provide both positive as well as negative examples of what can be achieved by applying nexus thinking and what goes wrong if you don’t. Key messages emerging include: (i) participatory approaches are a central element for successful implementation of a nexus approach, (ii) effective mechanisms of knowledge transfer are a prerequisite of adoption and upscaling of nexus approaches and (iii) the lack of economic incentives and lack of data represent major challenges for the implementation of a nexus approach. Overall, the importance of a nexus mindset of all stakeholders involved in nexus cases and of providing an enabling environment by nexus-oriented governance, including appropriate economic instruments, was confirmed

Governance of water-energy-food nexus: A social network analysis approach to understanding agency behaviour

Research seeks to treat each resource embedded in the nexus as connected to the other resources. This approach is unique from other natural resource research agendas where the primary focus is on system efficiencies or examinations of a single resource. The nexus by emphasizing trade-offs places a premium on coordination. From a governance perspective coordination is not limited to decisions involving finances and allocation of trained human resources among different agencies organized both vertically and horizontally within a multi-level governance framework. Coordination could also be extended to include uses of data between public agencies, private sector and individuals. Due to nexus interconnectivity, we suggest here that social network analysis (SNA) is an appropriate tool that can divulge and highlight the relational complexities that exist within the nexus and among stakeholders that work with the singular elements of the nexus. We suggest that in the cases of organisations with a high institutional capacity by means of expertise, resources, and other assets, the Water-Energy-Food (WEF) network will be highly connected between resource areas in the overall network. Two network tie characteristics—density and centrality—are particularly important to understand a critical mass of interests within a multi-level governance framework. The paper concludes by arguing for the organisation of data covering different dimensions of the Water-Energy-Food nexus through the mechanism of an observatory that could potentially improve our understanding of thresholds of environmental resource use and the incentives required for public agencies to act in support of sustainable development