further scope of applicability of the present invention will become apparent from the detailed description given hereinafter . however , it should be understood that the detailed description and specific examples , while indicating preferred embodiments of the invention , are given by way of illustration only , since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description . fig1 shows a section through an embodiment example of a tubular film die head 1 according to the invention , the bearing end of said tubular film die head being the housing 2 which in turn consists of the external nozzle ring 3 , the housing ring 4 , the housing base plate 5 , and the connecting plate 6 . in the circular interior of the housing , above all , are located the two bars 7 and 8 as well as the inner nozzle ring 9 . the components of the housing 2 and the aforementioned parts 4 to 6 bound an annular gap 10 through which the plastic melt reaches the die gap 11 and forms the film tube 12 . the plastic melt arrives in the aforementioned gap 10 through the feed lines 13 . before the mouth into the gap 10 , the feed lines are realized as helical grooves 14 in the bars 7 and 8 as well as the housing base plate 5 . in this case the helical grooves 14 are each bounded above by the component 7 , 8 , 9 which is located above the component 5 , 7 , 8 in which the grooves are introduced . due to the high pressure which prevails in the feed lines during operation , great lifting forces act on the bars 7 and 8 and the inner nozzle ring 9 , said forces having to be absorbed by the fastening means 15 a and b . the discharge of heated air is done by the stand pipe 18 and the fastening elements 15 a which contain air exhaust pipes 24 a . worth mentioning in addition is the advantageous distribution of the plastic melt through branching points 19 which are disposed in the center of the die head , as can also be seen in fig2 . the melt is conveyed via the central feed lines 20 . fig3 to 5 show different possibilities for constraining the fastening elements 15 . in fig3 the lower part of the hole for the fastening elements in the connecting plate 6 is provided with an inner thread 21 in which the outer thread 22 of the fastening elements 15 engages . the upper ends of the fastening elements 15 are once again provided with outer threads 22 and nuts 16 . often it is advantageous to provide the upper part of the hole for the fastening elements with a thread and to screw the fastening element into said thread . however , graphical representation of this form of embodiment was omitted . in fig4 heads 23 assume the role of the latter nuts 16 . the fastening of the lower ends of the fastening elements 15 b is done once again by screwing the same 15 b to the connecting plate 6 . the fastening elements 15 a again have a nut at this point . fig5 illustrates once more the fastening of the fastening elements with the nuts 16 . in the shown embodiment examples of the invention each fastening element 15 contains a line 24 . however , it is just as well conceivable that fastening elements contain an exhaust line 24 a and an intake line 24 b . other fastening elements can also get by without such lines 24 . the holes , through which the fastening elements engage , may be encased , at least in part , with a thermally insulating material 25 . the fastening elements may also consist , at least in part , of a thermally insulating material 25 and / or may contain cavities . the invention being thus described , it will be apparent that the same may be varied in many ways . such variations are not to be regarded as a departure from the spirit and scope of the invention , and all such modifications as would be recognized by one skilled in the art are intended to be included within the scope of the following claims .