The invention relates to a device and a method for filtering viscous or highly viscous liquids, in particular plastics melts, using an oscillating filter plate.

A filtering device for plastic materials in a molten state includes two filters made of a metal mesh and arranged side by side inside a filtration chamber, and a cleaning device between the two filters, the cleaning device in turn including one or more pairs of main hollow bodies provided with adhering walls that adhere to the filters or holed supports of the filters.

Methods for cleaning a die face for an extruder include: positioning an articulating tool adjacent the die face while the die face is installed on the extruder, the die face defining a plurality of die orifices; triggering operation of the articulating tool and thereby articulating an end effector coupled to the articulating tool; and contacting the end effector against one or more surfaces of the die face and thereby removing fouling from the die plate. Methods may include: pausing production of a polymer pellet product from the extruder when at least one of the pressure at the die or a polymer pellet product properties indicates fouling at the die; removing a polymer residue from one or more orifices in the die with an articulating tool equipped with an end effector while the die is mounted on the extruder; and resuming production of the polymer pellet product.

The invention relates to a filter device comprising an inlet chamber, an outlet chamber, a filter system which separates the inlet chamber and the outlet chamber. The filter device is characterised in that the inlet chamber comprises at least one liquid supply line and at least one liquid discharge line and the outlet chamber does not comprise a liquid supply and comprises at least one liquid discharge line. The invention also relates to a corresponding filter method.