Patent ID: 8911829

Claim:
A method of eliminating an optical defect in an extrusion coated film, comprising: conveying a film that is uniaxially or biaxially oriented to a coating station comprising an elastomeric roll nipped with a casting roll and an extrusion coating die adjacent to the nip, in which the surface speed of the elastomeric roll is controlled independently of the surface speed of the casting roll; contacting the film with the elastomeric roll while extruding a polymeric material into the nip, in which nip pressure is at least 100 pounds/linear inch (175N/cm), to make a coated film comprising a coated layer of polymeric material on the film; and adjusting the surface speed of the elastomeric roll to be different from the surface speed of the casting roll to eliminate optical defects in the coated film, such that: for uniaxially oriented film, surface speed of the elastomeric roll is adjusted to be greater than the surface speed of the casting roll by no more than 5%; and for biaxially oriented film, surface speed of the elastomeric roll is adjusted to be less than the surface speed of the casting roll by no more that 5%.