A device for imparting vibrational energy to polymeric pellets in a feed path of an extruder is disclosed. The device includes a feed path vibrator having an elongate imparting portion for being disposed within the feed path of the extruder, and a transfer portion extending from the imparting portion. The transfer portion is configured for coupling to a source of vibration energy, and the elongate imparting portion includes at least one twisted portion along its length.

A powder injection molding apparatus including an injection unit, mold formed of two mold parts with parting surface between first and second mold part, enclosing in assembled state of mold a mold cavity fluidically connected with injection unit via transfer channel, vibrational energy generator and transducer, and clamping unit designed to retain under the effect of clamping force first and second mold parts in contact with each other. Apparatus is characterized in that first and second mold parts include a first and second retaining hole, respectively, each extending essentially perpendicularly to parting surface and arranged opposite to each other respective to parting surface, clamping unit includes first and second pin each extending essentially perpendicularly to parting surface, wherein first and second pins cooperate in assembled state of mold with retaining portion of first and second retaining holes, respectively, to retain first and second mold parts in contact with each other.

A process for the preparation of an article by powder injection molding, the process including the steps of providing a feedstock containing a powder of a ceramic, a metal or a metal alloy dispersed in a binder, heating the feedstock, and injecting the heated feedstock into a mold cavity of a mold, where it cools and hardens to the configuration of the mold cavity. The process is characterized in that step c) is carried out under the application of vibrational energy onto the feedstock.