| 摘要 |
Method in manufacturing a heat insulated tube includes a tube (17) for conducting fluid and a sheath (12) enclosing said tube, a heat insulating material (15) being disposed between the fluid tube and the sheath. The sheath is being extruded in an angle extruder die (10) while the fluid tube and the heat insulating material enclosing said tube are being fed axially through the angle extruder die as the sheath is being extruded around the heat insulating material. Then the sheath (12) extruded from the angle extruder die is kept spaced from the heat insulating material (15) enclosing the fluid tube (17), over an initial length of the axial movement thereof up to chains of chill molds (13) for imparting to the sheath a corrugated shape by forming the sheath against the chains of chill molds under the influence of negative pressure. The invention also relates to a device in extruders having an angle extruder die (10) for the manufacture of the heat insulated tube. wherein a sleeve (20) is provided in the angle extruder die, said sleeve defining a passage for the heat insulating material (15) and the fluid tube (17) enclosed by said material, from the angle extruder die up to the chains of chill molds (13). |
