Produktgestaltung über mechanisches Agglomerieren von Pulvern

Fine powders produce dust, have low bulk densities and can be only handled poorly. Therefore, pressure agglomeration and build‐up agglomeration for transferring dry powders into manageable agglomerates are wide‐spread industrial methods. An agglomerate consists of many particles, interconnected by short material bridges. In case of press agglomeration, the highly viscous, plastic phases form the kit between the particles. However, the material bridges in the wet granulation arise from drying of the dissolved binder. The selection of suitable binders and the execution of scale‐up relevant pilot tests as well as the industrial design of pressure agglomeration and granulation installations are discussed.     

Influence of process variables on the characteristics of friction‐stir‐welded polyamide 6,6 joints

This paper aims to study the feasibility of friction stir welding of thermoplastic material polyamide 6,6. The maximum joint strength achieved through the optimized process variables is 41 MPa. The maximum temperature rise of 126 °C is achieved and the weld nugget exhibits a hardness of 69 D on Shore hardness scale. Fractography analysis reveals that the fracture followed a continuous plastic flow comprising less prominent fibrillation and more elongated voids. An increase in glass transition temperature T_g is observed in the weld specimen. The impact of the welding process variables on the frequency and band shift of the functional groups of the polymer is also discussed.