Patent ID: 7976667

Claim:
Method for bonding together up to three layers in a film, which may be made of layers of different materials, comprising the following steps: unwinding from a first pay-off unit ( 2 ) a first layer (S 1 ) of said film and guiding it into a first spreader/applicator ( 4 ) unit designed to apply an adhesive material to one side of said first layer and feeding it to a bonding zone ( 1 ); unwinding from a second pay-off unit ( 3 ) a second layer (S 2 ) of said film and guiding it into a second spreader/applicator unit ( 5 ) designed to apply an adhesive material to one side of said second layer and feeding it to the bonding zone ( 1 ); unwinding from a third pay-off unit ( 6 ) a third layer (S 3 ) of said film and feeding it to the bonding zone ( 1 ); bonding together in said bonding zone at least the first layer (S 1 ) and the third layer (S 3 ) by winding said at least first and third layers over a first bonding calender ( 18 ), along a contact arc on the surface of said calender, and pressing said layers by a presser roller ( 19 , 25 ) which is subject to the action of hydraulic actuator ( 23 , 29 ); taking up the bonded film; characterized by determining the breadth of said contact arc by rotating a nip ( 31 ) onto which the presser roller ( 19 ) is mounted, so as to vary the position of the point of contact between a presser roller ( 19 ) and the surface of said bonding calender ( 18 ).