Abstract: The invention relates to a filter device for polymer melts, having a filter screen (1), through which the polymer melt to be purified is guided, wherein the filter device comprises at least one scraping element (2), which glides across the upstream surface (4) of the filter screen (1) with its scraping edge (3), or rests on the surface (4) with its end area nearest the scraping edge (3), and lifts off and/or scrapes off the contaminations (6) adhering to the surface (4) and those present in front of the screen orifices (5) in the course of its movement across the surface (4). According to the invention it is provided that the scraping edge (3) has a curvature (7) at least in the end area of the same, leading in the direction of movement (16), the radius (R) of which is less than 90%, preferably less than 50%, in particular less than 20% of the maximum diameter, or of the maximum orifice width of the screen orifices (5).

Abstract: The present invention relates to a filtering device for fluids, in particular thermoplastics, comprising a screen carrier (2) which has a rotationally cylindrical outer face (41) and is mounted rotatably in a rotationally cylindrical recess (5), adapted to its circumference, of a stationary housing (3) and in which a number of screening nests (6) having filter arrangements (7) are formed along its circumference. According to the invention, there is provision whereby the screen carrier (2) is penetrated by a rotationally cylindrical core part (1) and is mounted rotatably on this, the core part (1) and the housing (3) being designed to be stationary and fixed in terms of rotation with respect to the rotatable screen carrier (2).

Abstract: The invention relates to a filter device for polymer melts, having a filter screen (1), through which the polymer melt to be purified is guided, wherein the filter device comprises at least one scraping element (2), which glides across the upstream surface (4) of the filter screen (1) with its scraping edge (3), or rests on the surface (4) with its end area nearest the scraping edge (3), and lifts off and/or scrapes off the contaminations (6) adhering to the surface (4) and those present in front of the screen orifices (5) in the course of its movement across the surface (4). According to the invention it is provided that the scraping element (2) is embodied in the shape of a disk, in particular comprising parallel, preferably plane large surfaces, i.e. a back face (8) and a front face (9) and is disposed at an inclined pitch (A) of 5 to 60°, preferably 10 to 45°, in particular 20 to 35° toward the surface (4) of the filter screen (1).

Abstract: The invention relates to a filter device for polymer melts, having a filter screen (1), through which the polymer melt to be purified is guided, wherein the filter device comprises at least one scraping element (2), which glides across the upstream surface (4) of the filter screen (1) with its scraping edge (3), or rests on the surface (4) with its end area nearest the scraping edge (3), and lifts off and/or scrapes off the contaminations (6) adhering to the surface (4) and those present in front of the screen orifices (5) in the course of its movement across the surface (4). According to the invention it is provided that the scraping edge (3) has a curvature (7) at least in the end area of the same, leading in the direction of movement (16), the radius (R) of which is less than 90%, preferably less than 50%, in particular less than 20% of the maximum diameter, or of the maximum orifice width of the screen orifices (5).

Abstract: The present invention relates to a filtering device for fluids, in particular thermoplastics, comprising a screen carrier (2) which has a rotationally cylindrical outer face (41) and is mounted rotatably in a rotationally cylindrical recess (5), adapted to its circumference, of a stationary housing (3) and in which a number of screening nests (6) having filter arrangements (7) are formed along its circumference. According to the invention, there is provision whereby the screen carrier (2) is penetrated by a rotationally cylindrical core part (1) and is mounted rotatably on this, the core part (1) and the housing (3) being designed to be stationary and fixed in terms of rotation with respect to the rotatable screen carrier (2). (FIG.