Patent ID: 7819077

Claim:
A die coater comprising a first die block, a second die block, and a plurality of fasteners holding the first die block and the second die block together, wherein: (a) each of the plurality of fasteners extends through the first die block, into the second die block, and provides a compression force between the first die block and the second die block; (b) the first die block and the second die block are constructed to provide an internal manifold and a coating slot; and (c) some of said fasteners are located behind the internal manifold, where the term behind is with reference to the die face being considered the front of the die coater, and are arranged so that some are rearward fasteners and some are forward fasteners, the forward fasteners being closer to the coating slot of the die than the rearward fasteners, said die coater characterized in that: the fasteners of part (c) comprise a forward row of fasteners and a rearward row of fasteners in which O F refers to the distance between a forward fastener and the internal manifold, O B refers to the distance between the rearward fastener and the die back surface, and the forward and rearward fasteners are spaced symmetrically so that the value of O F is approximately the same as O B ; at least two of said fasteners, one rearward fastener and the forward fastener nearest said rearward fastener, have a torque differential of greater than about 5%; the die coater has an overhang O H , defined as the linear distance along the first die block surface facing the coating slot of the die from the rear of the die manifold to the leading edge of the die slot, of less than about 119 mm; the cube of the ratio of overhang to the thickness of the first die block is less than about 9; and the quantity defined by the cube of the ratio of the overhang/thickness divided by the modulus of elasticity of the first die block is less than about 3.0×10 −7 in 2 /lb (4.35×10 −5 Mpa −1 ).