BIAXIALLY-ORIENTED POLYPROPYLENE FILM FOR DIRECT-BONDING LAMINATION ON PAPER AND METHOD OF ITS PRODUCTION Russian patent published in 2011 - IPC B32B27/06 B32B27/32 B32B27/18 B29D7/01 B29C47/06 B29C71/02 B29C71/04 B32B27/10 C08J5/18 

FIELD: process engineering.

SUBSTANCE: invention relates to production of polypropylene films. Proposed film comprises surface layer, center layer and functional layer arranged in this order, co-extruded and biaxially oriented. Functional layer may be laminated by hot pressing directly on paper or other film. Top subsurface layer is located between surface and center layer while underlaying subsurface layer is located between center and functional layers. Proposed method comprises: feeding raw stock into extruder for it to be plasticised to melt, passing said melt via channel, filtration, distribution of melt into extrusion head and co-extrusion. Film is produced with the help of flat-slot extrusion head or by forming the sleeve. Film is processed by corona discharge or fire to produce machine winding roll, aged and cut longitudinally.

EFFECT: power savings, higher safety.

7 cl, 3 dwg, 12 ex