| 摘要 |
Extruder with blow head comprising a cylindrical body containing at least one rotating screw in coaxial position, a feeding device for the thermoplastic material near one end of the cylinder and a blow head comprising a housing and a mandrel at the other end of the cylinder forming a slit tapering in the direction of flow of the plasticized material and through which said material issues, the screw and the blow head being arranged in one plane, and directly behind the blow head a cooling device for cooling the extruded tube, wherein A. THE SCREW AND THE MANDREL ARE RIGIDLY CONNECTED WITH EACH OTHER WITHOUT ANY DISTORTION BEING POSSIBLE, B. THE LIP OF THE HOUSING OF THE BLOW HEAD PROTRUDES FROM 0.1 TO 10 MM OVER THE LIP OF THE MANDREL, C. THE DIAMETER OF THE SLIT FORMED BY THE HOUSING AND THE MANDREL IS IN THE RANGE OF FROM 1 TO 20 MM IN THE MOST NARROW AREA, AND D. THE SURFACE OF THE HOUSING FACING THE SURFACE OF THE MANDREL HAS A HIGHER ADHESION TO THE PASSING PLASTICIZED THERMOPLASTIC MATERIAL THAN THE SAID SURFACE OF THE MANDREL. |
