to lean against the metal edge with a control excursion and are slightly reluctant to lift up on top of the metal strip which helps to improve reliability however it is vital that the edge sensors properly detect the edge position and knife to metal contact is avoided fig2 a shows only one pair of score cut knives in another preferred embodiment fig2 b shows a how a redundant pair of score knives may be used to trim at an edge of the strip in a preferred embodiment side trimming knives may be employed on the film before the laminating step to trim the film width dynamically to the strip width this method is preferred in the cases where the polymer film becomes sticky and is difficult to trim away reliably from the hot metal some polymers have been known to create u2018 stringers u2019 where the score cut knife is unable to satisfactory cut through the softened polymer film also in some cases the polymer film has a tendency to adhere to the knife by trimming the film directly just before laminating the film width can be adjusted to the correct width by ensuring the metal is completely covered.