Described herein is a liquid injector for a barrel extruder as well as methods and processes of manufacturing irradiation crosslinked polypropylene foam. In some embodiments, this includes a liquid injection barrel element that is incorporated in an extruder barrel that includes at least one injection port, a temperature sensor well, and cooling channels.

The invention relates to a filter device for a plastic melt or another highly viscous fluid, comprising a housing with an inlet plate and a discharge plate. At least one spacing element and a screen wheel which can be rotated by a drive device are arranged between the inlet plate and the discharge plate. The inlet plate and the discharge plate are clamped against each other with the inclusion of the spacing element via at least three housing clamping elements. An engagement point of the drive device on the screen wheel is arranged outside of the pretensioning surface. When viewed in the rotational direction, an angle α larger than 110° and smaller than 160° is formed on the screen wheel between a first line that extends between the pretensioning surface centroid on which a resulting frictional force F.sub.R acts and the center of the screen wheel and a second line between the center and the engagement point on which an advancing force F.sub.V acts.

A filtering device for highly viscous media, in which filtering device a rotatably mounted screening wheel which has a plurality of screening cavities is arranged between a front housing element and a rear housing element. According to the invention, a plurality of screening cavities lying beside one another, through which flow can pass jointly, are combined into at least one filter group. To this end, on both sides beside the filter group, a closed blocking segment is provided on the screening wheel which segment, when positioned in associated blocking regions of the housing, is sealed off with respect to the housing elements on both sides of the screening wheel. The blocking regions in the housing are in each case larger than or as large as a screening cavity together with a sealing web surrounding the same.

A method for producing low density polyester foam utilizing low I.V. polyester feedstock includes providing a low intrinsic viscosity raw material. The low intrinsic viscosity raw material includes between 25% to 100% of a post consumer polyester and has an intrinsic viscosity of less than 0.8 dl/g. The intrinsic viscosity of the low intrinsic viscosity raw material is increased via a de-condensation reaction configured to support foaming. The intrinsic viscosity of the low intrinsic viscosity raw material is increased to 1.1 dl/g or greater. A starting formulation is created including the low intrinsic viscosity raw material with the increased intrinsic viscosity. The starting formulation is foamed to create the polyester foam. Wherein, the polyester foam produced has a specific gravity of less than 0.65 g/cc.

A device and a method for filtering viscous or highly viscous liquids, in particular plastics melts, includes use of an oscillating filter plate.

A device and a method for filtering viscous or highly viscous liquids, in particular plastics melts, includes use of an oscillating filter plate.

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.

Extrusion die systems, die changers and related methods are provided herein. The die changer for changing of dies in and out of an extrusion line can include a housing having a main supply feed bore therethrough for directing a flowable material and a channel oriented transversely to the main supply feed bore. The die changer can include a slide plate movable through the channel and transverse to a direction of flow through the bore. The slide plate can include an elongate body having a first section and a second section. A first bore can extend through the first section of the elongate body of the slide plate and a second bore can extend through the second section of the elongate body of the slide plate. The slide plate of the die changer can be moved within the channel of the housing between a first position where the first bore in the first section of the elongate body of the slide plate is aligned with the main supply feed bore and a second position where the second bore in the second section of the elongate body of the slide plate is aligned with the main supply feed bore.

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.

Described herein is a liquid injector for a barrel extruder as well as methods and processes of manufacturing irradiation crosslinked polypropylene foam. In some embodiments, this includes a liquid injection barrel element that is incorporated in an extruder barrel that includes at least one injection port, a temperature sensor well, and cooling channels.