Abstract: An annular co-extrusion die for extruding multi-layer tubular plastic film has a lower part and an upper part. The lower part has concentric radially spaced lower die members of different diameters forming at least two lower concentric radially spaced annular passages communicating with a common annular passage for separately feeding different plastic materials along the lower annular passages to the common annular passage for extrusion therefrom. The upper part has upper annular die members located above the lower die members and stacked one upon another. The upper annular die members forms at least one upper annular passage for separately feeding different plastic materials along each upper annular passage to the common annular passage for extrusion therefrom with the plastic materials from the lower annular passages as a multi-layer tubular plastic film.

Abstract: An annular co-extrusion die for extruding multi-layer tubular plastic film has inner die members stacked one upon another. The inner die members have radially outwardly extending surfaces forming radially outwardly extending helical passages between respective pairs of die members. An annular outer die member surrounds the stacked inner die members and forms a longitudinally extending annular passage therebetween for conveying plastic material from the radially outwardly extending helical passages to an annular extrusion orifice. Each inner die member forms with an adjacent die member a first feed passage extending at least partly around the inner die member radially inwardly of the helical passages, the inner die member and the adjacent die member having a circumferentially extending clearance therebetween to enable plastic material fed into the first feed passage to pass through the clearance into the helical passages.

Abstract: Apparatus for effecting gauge distribution in flattened tubular plastic film has a collapsing device for collapsing upwardly vertically moving expanded tubular plastic film to a two layer flattened condition, a first motor for rotating the collapsing device through 180.degree. in each direction from a neutral position, a first horizontal film direction reverser secured to the collapsing device for rotation therewith a first horizontal turning bar located above the collapsing device and extending substantially through the central axis, a second horizontal film direction reverser, and a second horizontal turning bar located about the first turning bar. A second motor arrangement simultaneously rotates the first turning bar through 135.degree. in each direction from a neutral position, the second film direction reverser through 90.degree. in each direction from the neutral position and the second turning bar through 45.degree. in each direction from the neutral position simultaneously with the 180.degree.