Abstract: A foam forming device has an inlet, an outlet and a longitudinal axis that leads from the inlet to the outlet. The foam forming device has a plurality of surface pairs. Each surface pair has two opposing surfaces. The surfaces delimit a foaming space at least to some extent. At least one of the surfaces of the surface pairs is an adjustable surface whose orientation relative to the longitudinal axis can be adjusted. The first surface pair and the second surface pair are off-set from one another along the periphery of the foaming space. Also disclosed is a foam extrusion apparatus having a foam forming device.

Abstract: A method and an extrusion device for producing a foamed body. A plastics melt is produced inside the casing of a first extruder. The plastics melt is conveyed to an outlet die of a second extruder. The conveyed plastics melt has a foaming agent and expands after being fed through the outlet die. Before the plastics melt is fed through the outlet die, variations in temperature between different radial positions over the cross-section of the plastics melt are reduced by an extruder screw device which has a number of screw spindles distributed around the periphery. The plastics melt which is thus thermally homogeneous is fed through the outlet die.

Abstract: A mixer structure for a film die for a polymer melt includes multiple web elements. The web elements include a first web element and a second web element. The first web element and the second web element include at least an end, which is connected to a base. A film die includes a first tool element, a second tool element, and a flow channel for the polymer melt extending between the first tool element and the second tool element. The mixer structure is arranged in the flow channel. The mixer structure is held in at least one of the tool elements by a holding element.

Abstract: A device (4) for the manufacture of an annular extrudate comprises a jacket (2), a crosshead (1) arranged inside of the jacket. The jacket contains a melt passage, whereby the crosshead is arranged in the melt passage, such that the melt passage extends et least at the outlet of the device as an annular melt passage around the crosshead (1). An annular passage (5) is formed between the crosshead and the jacket. The annular passage contains a static mixer (3), whereby the crosshead is at least partially supported by the static mixer in the jacket. The static mixer comprises a plurality of inserts, whereby at least a portion of the inserts is connected to the crosshead and/or the jacket.

Abstract: A mixer structure for a film die for a polymer melt includes multiple web elements. The web elements include a first web element and a second web element. The first web element and the second web element include at least an end, which is connected to a base. A film die includes a first tool element, a second tool element, and a flow channel for the polymer melt extending between the first tool element and the second tool element. The mixer structure is arranged in the flow channel. The mixer structure is held in at least one of the tool elements by a holding element.

Abstract: A device (4) for the manufacture of an annular extrudate comprises a jacket (2), a crosshead (1) arranged inside of the jacket. The jacket contains a melt passage, whereby the crosshead is arranged in the melt passage, such that the melt passage extends et least at the outlet of the device as an annular melt passage around the crosshead (1). An annular passage (5) is formed between the crosshead and the jacket. The annular passage contains a static mixer (3), whereby the crosshead is at least partially supported by the static mixer in the jacket. The static mixer comprises a plurality of inserts, whereby at least a portion of the inserts is connected to the crosshead and/or the jacket.

Abstract: For forming an extrusion-foamed plastic layer, the plastic layer is first thermally treated in order to be at least particularly plastically deformable. Negative pressure is exerted on the plastic layer, pulling it apart in the direction of the thickness as a plastic deformation. The plastic layer is optionally pressed together to a desired thickness or introduced into a mold. The negative pressure leads to a greater cell size homogeneity. The thickness of the plastic layer smoothed. Further, a corresponding aftertreatment device is proposed. This includes a thermal treatment device or thermal treatment zone. At least one pair of opposing negative pressure surfaces follows in conveying direction. These pull apart the plastic layer. Optionally, the plastic layer is additionally cooled. Further, and the plastic layer may be further processed in a subsequent fabricating unit.

Abstract: A method and an extrusion device for producing a foamed body. A plastics melt is produced inside the casing of a first extruder. The plastics melt is conveyed to an outlet die of a second extruder. The conveyed plastics melt has a foaming agent and expands after being fed through the outlet die. Before the plastics melt is fed through the outlet die, variations in temperature between different radial positions over the cross-section of the plastics melt are reduced by an extruder screw device which has a number of screw spindles distributed around the periphery. The plastics melt which is thus thermally homogeneous is fed through the outlet die.

Abstract: A method for producing a foamed body includes generating a plastics melt within a casing of a first extruder; and conveying the plastics melt to an outlet nozzle of a second extruder, having an extruder screw apparatus. The conveyed plastics melt has foaming agent and expands after being conducted through the outlet nozzle. In first length sections of the extruder screw apparatus of the second extruder, the plastics melt is conveyed and/or mixed. In second length sections of the extruder screw apparatus of the second extruder, the plastics melt is conveyed and pressure is built up in the plastics melt. The plastics melt is guided alternately through first and second length sections. Before the plastics melt is guided through the outlet nozzle, temperature differences between different radial positions in the cross section of the plastics melt are reduced, and the thermally homogenized plastics melt is conducted through the outlet nozzle.

Abstract: The invention relates to a method for producing an extruded foam product. An extrudate mixed with at least one blowing agent is guided through an extrusion tool (100). After the extrudate exits the extrusion tool, the extrudate is foamed by the blowing agent in order to create a foamed mass (110). Surface, edge-layer, or complete hardening of the foamed mass (110) exiting the extrusion tool within a temperature-control zone (106) adjacent to the extrusion tool is prevented by the temperature control of the foamed mass (110) within the temperature-control zone. The invention further relates to a device for performing said method.

Abstract: The invention relates to an extrusion plant for manufacturing foam products such as foamed sheets, foamed boards and foamed profiles, and consists of one melting extruder minimum to melt and homogenise the plastic material and a minimum of two parallel cooling units to cool down the plastic melt prior to extrusion through a die. According to the invention it is planned that the minimum of two parallel cooling units are used that may or may not be identical or that can be controlled by control means so that the expelled plastic melt from these units may or may not have the same material properties.