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.

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.

A filter candle to separate contaminants from a plastic melt is disclosed. The filter candle has a filter element through which a melt flow is directed to retain contaminants contained in the melt flow, and a supporting body to support the filter element. The supporting body is a hollow body having multiple passages for the melt flow. At least one additional supporting body is on the side of said filter element that faces away from the supporting body. The additional supporting body acts on surface regions of the filter element and/or accommodates them such that the filter element can be backwashable.

A polymer melt candle filter having a support which comprises a hollow cylindrical body defined by a first end, a second end, and a cylinder wall having a first end portion and a second end portion. The first end portion includes a screw thread on its outside surface and optionally a hex fitting on its inside surface for receiving a hex wrench. The second end portion includes a plurality of holes in the cylinder wall. The area of the openings of the holes on the outside surface of the cylinder wall may be larger than the area of the openings of the corresponding holes on the inside surface of the cylinder wall. The shape of the openings of the holes on the outside surface may be non-circular. A polymer melt filter plate assembly which comprises (a) a support plate comprising a plurality of threaded holes; (b) at least one filter which is screwed into at least one of the threaded holes via the screw thread on the outside surface of the first end portion of the filter support; (c) a tie rod with (i) a first end extending through a hole in a cone insert and a cap located at the second end of the filter support, and (ii) a second end extending through a threaded hole in the support plate; and (d) a cross bar which is attached to the second end of the tie rod for holding the support plate inside a shaft of an apparatus for filtering a polymer melt.

A polymer melt candle filter having a support which comprises a hollow cylindrical body defined by a first end, a second end, and a cylinder wall having a first end portion and a second end portion. The first end portion includes a screw thread on its outside surface and optionally a hex fitting on its inside surface for receiving a hex wrench. The second end portion includes a plurality of holes in the cylinder wall. The area of the openings of the holes on the outside surface of the cylinder wall may be larger than the area of the openings of the corresponding holes on the inside surface of the cylinder wall. The shape of the openings of the holes on the outside surface may be non-circular. A polymer melt filter plate assembly which comprises (a) a support plate comprising a plurality of threaded holes; (b) at least one filter which is screwed into at least one of the threaded holes via the screw thread on the outside surface of the first end portion of the filter support; (c) a tie rod with (i) a first end extending through a hole in a cone insert and a cap located at the second end of the filter support, and (ii) a second end extending through a threaded hole in the support plate; and (d) a cross bar which is attached to the second end of the tie rod for holding the support plate inside a shaft of an apparatus for filtering a polymer melt.

Techniques recycle plastics in multiple successive process steps. A polymer, preferably a recyclable material, is melted using a discharge extruder, filtered using a first filter device under a positive pressure atmosphere, filtered and degassed using a degassing device, and discharged using a discharge extruder. The degassing device has at least one filter element and a vacuum chamber with a negative pressure atmosphere for filtering and degassing purposes, wherein the plastic melt can be conducted into the negative pressure atmosphere of the vacuum chamber through the filter element.

Techniques recycle plastics in multiple successive process steps. A polymer, preferably a recyclable material, is melted using a discharge extruder, filtered using a first filter device under a positive pressure atmosphere, filtered and degassed using a degassing device, and discharged using a discharge extruder. The degassing device has at least one filter element and a vacuum chamber with a negative pressure atmosphere for filtering and degassing purposes, wherein the plastic melt can be conducted into the negative pressure atmosphere of the vacuum chamber through the filter element.

Apparatus and methods for extruding plastic materials are disclosed. An exemplary apparatus comprises: a feeding portion; a melting portion in communication with the feeding portion and configured to transmit heat into material received from the feeding portion; and an output die in communication with the melting portion to permit extrusion of the material. The melting portion comprises: a melting barrel having an inner surface defining a melting chamber in communication with the feeding portion; and a melting insert inside the melting chamber. The melting insert comprises an outer surface in contact with the inner surface of the melting barrel where the outer surface comprises one or more open-ended channels formed therein. In some embodiments, the feeding portion and the melting portion may be thermally insulated from each other and a propeller of the feeding portion may be disposed entirely outside of the melting portion.

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.

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.