Consolidation process boundaries of the degradation of mechanical properties in compression moulding of natural-fibre bio-polymer composites

In spite of the volume of literature on natural fibres, bio-matrix materials and their composites, the choices of optimum process parameters such as moulding temperature, pressure and compression time are still largely based on experience, rules of thumb and general knowledge of the chemical and physical processes occurring in the melt during consolidation. The moulding process itself is a complex balance between processes that must occur for the composite to successfully consolidate and the onset of thermal degradation of the natural fibre and/or matrix materials. This paper brings together models of thermal penetration, melt infusion, thermal degradation and chemical degradation of natural polymers to construct an ideal processing window for a bio-composite. All processes are mapped in terms of normalized consolidation progress parameters making it easier to identify critical processes and process boundaries. Validation of the concept is achieved by measuring changes in the mechanical properties of a flax/PLA bio-composite formed over a range of processing conditions within and outside of the optimized window

Properties of Broezel static probe

The properties of flat static probe designed by Broezel and used in sailplanes are investigated for its planned use in low speed tunnel. Both the numerical CFD model and experiment in low speed wind tunnel confirm yaw insensitivity of the static pressure measured by the probe. The results indicate that the probe is sufficiently accurate for its planned use in wind tunnel measurements

Properties of Broezel static probe

The properties of flat static probe designed by Broezel and used in sailplanes are investigated for its planned use in low speed tunnel. Both the numerical CFD model and experiment in low speed wind tunnel confirm yaw insensitivity of the static pressure measured by the probe. The results indicate that the probe is sufficiently accurate for its planned use in wind tunnel measurements

Geometric Modification of the Tundish Impact Point

In connection with the increasing requirements for cleanliness in conticast steel, it is necessary to develop original solutions. The tundish, as the last refractory-lined reactor, gives enough space to remove inclusions by optimizing the flow of steel. The basic component of the tundish is the impact pad, the shape of which creates a suitable flow of steel, thus making it part of the tundish metallurgy. The optimal steel flow in the tundish must avoid creating dead zone areas, or the slag “eye” phenomenon in the slag layer around the ladle shroud, and is intended to create conditions for the release of inclusions by promoting reactions at the steel-slag phase interface. The flow also has to prevent excessive erosion of the tundish refractory lining. This paper compares the standard impact pad with the “Spheric” spherical impact pad using computional fluid dynamiscs (CFD) tools and physical modelling. The evaluation criteria are residence time and flow in the tundish at three different casting speeds

Properties of Broezel static probe

The properties of flat static probe designed by Broezel and used in sailplanes are investigated for its planned use in low speed tunnel. Both the numerical CFD model and experiment in low speed wind tunnel confirm yaw insensitivity of the static pressure measured by the probe. The results indicate that the probe is sufficiently accurate for its planned use in wind tunnel measurements