DOUBLE-SIDED WELDABLE ORIENTED MULTI-LAYER POLYOLEFIN FILM SUITABLE FOR PRINTING AND METHOD OF MANUFACTURE OF SUCH FILMS Russian patent published in 2003 - IPC

FIELD: manufacture of multi- layer polyolefin films. SUBSTANCE: proposed film contains one main layer and double-sided covering coats including hydrocarbon resin. Both covering layers contain silicon oil at viscosity of 350-500000 cSt and at least one surface of film is subjected to treatment. Proposed method includes co-extruding melts corresponding to separate layers of film, after which co-extruded film is passed through flat slotted head and rolls at temperature of 80-110 C; film is biaxially stretched at relationship of longitudinal tension from 4:1 to 7:1 and transversal tension from 8:1 to 10:1; biaxially oriented film is stabilized thermally, subjected to surface treatment and rolled. Laminate includes multi-layer polyolefin film and paper or cardboard or another film made from thermoplastic polymer. EFFECT: enhanced efficiency. 11 cl, 1 tbl, 1 ex