Apparatus for shaping tubular film

Claim 1

An apparatus for supporting, calibrating and coagulating a tubular film during a downward film blowing process comprising a. an extruding means for thermoplastic polymer including an annular die that has an extruding slit, b. a feeding pipe for pressurized air that is to inflate the extrudate into a tubular film, c. a coagulant distributing means located concentrically below said extruding slit and including a coagulant distributing vessel and piping for suppling coagulant, d. a taking up means for said tubular film, e. a flexible cylindrical net which concentrically surrounds said tubular film for a substantial part of its inflated length, f. a cylindrical passageway beneath said annular die which has a size and shape to accommodate the downward passage of the tubular film in its inflated condition, g. the upper end of said flexible cylindrical net being suspended from said passageway beneath said coagulant distributing means, h. the lower end of said net facing said taking up means and being fixed to a ring member provided with a stretching means for said net which is capable of adjusting the diameter of said net to the approximate diameter of said inflated tubular form, i. a reduced pressure chamber with exhaust piping means, said chamber extending beneath said coagulant distributing means and surrounding both said inflated tubular film and said flexible cylindrical net, j. the upper portion of said cylindrical passageway that is adjacent to the point where the coagulant liquid first contacts the top of said net being composed of at least two ring members that concentrically surround said inflated tubular film and are vertically stacked upon one another in a coaxial manner, k. the inside walls of said ring members being provided with a plurality of grooves that are each inclined with respect to a plane through the circumference of the ring member, l. the inside walls of said ring members also each being provided with a groove around the internal circumference and which is positioned adjacent one internal edge portion, whereby stacked ring members present a downward flow path that permits the coagulant to flow down uniformly between the inner walls of the ring members and the other wall of the tubular film, m. a sealing device furnished on the periphery of the lower opening of the reduced pressure chamber through which the tubular film enveloped in the net passes, and n. a passgeway for discharging surplus coagulant that collects in the bottom of the reduced pressure chamber.

Claim 2

An apparatus for supporting, calibrating and coagulating a tubular film during a downward film blowing process comprising a. an extruding means for thermoplastic polymer including an annular die that has an extruding slit, b. a feeding pipe for pressurized air that is to inflate the extrudate into a tubular film, c. a coagulant distributing means located concentrically below said extruding slit and including a coagulant distributing vessel and piping for suppling coagulant, d. a taking up means for said tubular film, e. a flexible cylindrical net which concentrically surrounds said tubular film for a substantial part of its inflated length, f. a cylindrical passageway beneath said annular die which has a size and shape to accommodate the downward passage of the tubular film in its inflated condition, g. the upper end of said flexible cylindrical net being suspended from said passageway beneath said coagulant distributing means, h. the lower end of said net facing said taking up means and being fixed to a ring member provided with a stretching means for said net which is capable of adjusting the diameter of said net to the approximate diameter of said inflated tubular form, i. a reduced pressure chamber with exhaust piping means, said chamber extending beneath said coagulant distributing means and surrounding both said inflated tubular film and said flexible cylindrical net, j. the upper portion of said cylindrical passageway that is adjacent to the point where the coagulant liquid first contacts the top of said net being composed of at least two ring members that concentrically surround said inflated tubular film and are vertically stacked upon one another in a coaxial manner, k. the inside walls of said ring members being provided with a plurality of grooves that are each inclined with respect to a plane through the circumference of the ring member, l. the inside walls of said ring members also each being provided with a groove around the internal circumference and which is positioned adjacent one internal edge portion, whereby stacked ring members present a downward flow path that permits the coagulant to flow down uniformly between the inner walls of the ring members and the other wall of the tubular film, m. a sealing device furnished on the periphery of the lower opening of the reduced pressure chamber through which the tubular film enveloped in the net passes, and n. a passgeway for discharging surplus coagulant that collects in the bottom of the reduced pressure chamber.