Image Number 5 for United States Patent #6533570.
An extruder die head, preferably a blown film head, comprises an internal cylindrical mandrel and a jacket, which envelops concentrically said mandrel. Between said mandrel and jacket an annular channel is formed that empties into a die slit. The invention also comprises at least one line, which empties into the annular channel in the area opposite the die slit and which feeds a melt. To prevent a slit between the central mandrel and the jacket, enclosing said mandrel, where the polymer melt could accumulate and deposit, the mandrel is made as one piece with a flange-shaped foot. The jacket rests with its bottom face sealingly on the annular surface of the flange-shaped foot and is connected, for example fastened, to the same. The annular channel extends from the peripheral surface of the mandrel to the flange-shaped foot up to and into the transition region. The line, feeding in a melt, empties into this transition region.