Abstract: The invention relates to an arrangement in connection with extrusion tools. It comprises a nozzle structure which is provided with coaxially arranged nozzle elements (1, 2, 3, 4) and is arranged to form one or more layers which cover a flexible elongated element (6) on the surface of the flexible elongated element (3), which passes through the innermost nozzle element (4), and a guide member (5) corresponding the diameter of the elongated element (6) for controlling the flexible elongated element (6). The guide member (5) is arranged to be pushed in the direction of the elongated element (6) into its position inside the two innermost nozzle elements (3, 4) defining a first melt channel (7). The guide member (5) is arranged to provide a tapered space (52) between the elongated element (6) and the guide member (5), and the tapered space (52) is in fluid communication with the first melt channel (7).

Abstract: The invention relates to an arrangement in connection with extrusion tools. It comprises a nozzle structure which is provided with coaxially arranged nozzle elements (1, 2, 3, 4) and is arranged to form one or more layers which cover a flexible elongated element (6) on the surface of the flexible elongated element (3), which passes through the innermost nozzle element (4), and a guide member (5) corresponding the diameter of the elongated element (6) for controlling the flexible elongated element (6). The guide member (5) is arranged to be pushed in the direction of the elongated element (6) into its position inside the two innermost nozzle elements (3, 4) defining a first melt channel (7). The guide member (5) is arranged to provide a tapered space (52) between the elongated element (6) and the guide member (5), and the tapered space (52) is in fluid communication with the first melt channel (7).

Abstract: The invention relates to a process of crosslinking a polymer material with silane by means of heat, in which process a polymer, a grafting agent, an initiator and a crosslinking catalyst and optional additives are fed into an extruder and extruded to a homogenous mass by keeping the process temperature so low that the initiator used does not degrade during the extrusion and the optional additives do not react or degrade in the extruder, and, after the extrusion, the extruded mass is grafted and crosslinked. After the extrusion, the process of the invention comprises a step of heating the initiator, mixed homogenously with the polymer material, by means of infared radiation in a wavelength range absorbed by the initiator.

Abstract: The invention concerns an extruder head for regulating the temperature of a flow of molten plastic containing a foaming agent. In the flow passage of the extruder head is arranged a mixer which is inductively heated and transfers heat to the plastic flow thereby regulating the temperature thereof during the passage through the extruder head.