HUP0402669A2 - Apparatus for continuous producing of blown film - Google Patents

Abstract

An extrusion apparatus for continuous manufacturing extruded plastic foil hose, comprises internal and/or external cooling device formed as multiple-stage device arranged preferably direct on extruder die (E) and coaxially with drawing orifice (H) and having multi-level tangential outlets for coolant to stabilize first conical non-stabilized section (M) of expanded foil hose by internal and/or external spiral coolant stream. An extrusion apparatus for continuous manufacturing extruded plastic foil hose, comprises an extruder with a die for forming the foil hose by its annular drawing orifice; and an internal and/or an external cooling device surrounding the drawing orifice and a portion of the expanded foil hose. The internal and/or external cooling device is provided with an inlet for a coolant, preferably cooling air, connected to a coolant supply, and at least one outlet supplying coolant into an annular gap between the expanded foil hose to be cooled and an annular skirt of the internal and/or the external cooling device. The internal and/or external cooling device is formed as multiple-stage device arranged preferably direct on the extruder die and coaxially with the drawing orifice and having multi-level tangential outlets (14-16) for the coolant to stabilize a first conical non-stabilized section of the expanded foil hose (F) by internal and/or external spiral coolant stream. The multiple-stage internal cooling device comprises at least two annular cooling-orienting units arranged at axial distance from each other, surrounding internally partly the non-stabilized section of the foil hose through the internal main annular gap. Each of the internal annular cooling-orienting units is connected to the coolant supply in such a way to supply the coolant of selectively and individually adjustable temperature and/or volume and/or pressure. The multiple-stage external cooling device (1) comprises at least two annular external cooling units (2-4) arranged at an axial distance from each other, surrounding externally partly the conical non-stabilized section of the expanded foil hose through the external main annular gap (G). Each external cooling-orientating unit is provided with at least one tangential inlet and is connected to a second coolant supply in such a way to supply the coolant of selectively and individually adjustable temperature and/or volume and/or pressure. An independent claim is also included for a process for producing plastic foil hose, comprising: (A) surrounding a portion of non-stabilized expanded section of the foil hose just exiting from a drawing orifice of an extruder die by using an external multi-stage cooling device and providing thus an external main ring gap at radial distance from an external surface of the foil hose and/or by using an internal multi-stage cooling device and providing thus an internal main ring gap at a radial distance from the internal surface of the foil hose; and (B) supplying coolant of selectively predetermined temperature and/or pressure and/or volume, mainly cooling air, into the external and/or internal main ring gap(s) through axially multi-level tangential inlets and directing the tangential coolant streams onto the external and/or internal surface(s) of the non-stabilized section of the foil hose in order to cool externally and/or internally the non-stabilized section of the foil hose and thus to stabilize its structure by generating spiral coolant stream from the multi-level tangential coolant streams within the external and/or internal main ring gap(s) by using a centrifugal force affecting the coolant streams along the external and/or internal surface(s) of the expanded foil hose, and by using density and pressure differences between various parts of the coolant flows.