FIELD: technological processes.
SUBSTANCE: group of inventions relates to the method and device for longitudinal orientation of a thermoplastic film material (20). At the same time there is a zone of narrowing in front of a zone of longitudinal stretching (9, 10), in which film width gradually diminishes so that it provides longitudinal stretching without transverse narrowing. The narrowing zone includes at least two rows of corrugated rollers (7, 1), including engaging grooves, or discs for material corrugation. Lower rollers (1) include a mini roller, which defines the following dimensions: a) corrugation pitch, measured from the middle of the ledge to the middle of the adjacent ledge, makes 20 mm or less, b) ratio of the sum of distances from the middle of the ledge to the middle of each adjacent ledge, measured along the surface of the corrugated roller, to the corrugation pitch is in the interval from 1.10 to 1.80, c) diameter of the mini roller measured by ledges of corrugation, exceeds the specified pitch not more than 4 times. Preferably, a pair of rows of mini rollers is located on the opposite sides of the film in fixtures with reciprocal motion, which provides for alternate winding of the film around one and then another mini roller.
EFFECT: achievement of high values of tensile strength, yield point, resistance to rupture propagation and puncture resistance, mainly for polyethylene and polypropylene films.
22 cl, 5 dwg
