METHOD AND APPARATUS FOR MANUFACTURE OF A POLYMER FILM, WHICH IS ORIENTED UNDER AN ANGLE TO ITS LONGITUDINAL DIRECTION

摘要

591455 A method and apparatus for manufacturing a polymer film (20) oriented at an angle to its longitudinal direction is disclosed. A lay-flat tubular film (9) is unwound and longitudinally oriented between stretching rollers (107-112). The oriented film (9) is unwound from a tumbling unwinding stand (6) to rotate the lay-flat tube (9) around its longitudinal axis and then is expanded over a mandrel (14) and propelled in a screwing movement. A stationary knife (18) cuts the film in a helix and the cut film is pulled away from the mandrel (14).