Patent ID: 6986916

Claim:
A method for applying a coating solution on a web, comprising: feeding said web continuously; and discharging said coating solution from a slot of a die, said discharged coating solution flowing on a slide surface of said die onto said web, with a bead formed between the slide surface and the web, a width of said coating solution being regulated by edge members which are provided in both sides on said slide surface, each said edge member having a regulation portion which is perpendicular to said slide surface and faces the other regulation portion, wherein a height Dg of said regulation portion satisfy a condition Db≦Dg≦Ds, Db being a minimum thickness of bead at vena contracta and Ds being an upper limit of a height of said regulation portion, which are represented as follows, Db =1.03× h 1 −1.50 ×he×U −1/3 +12800 ×he 2 ×U Ds ( m )={3×η ×q /( ρ×g ×sin α)} 1/3 wherein h 1 is a distance between said web and a lip of said die in m, he is a thickness of said coating layer formed on said web as the coating solution flows onto the web, in m, U is a feeding velocity of said web in m/s, η is an averaged viscosity of solution flowing on said slide surface at a shear rate in m·Pa·s, q is a total amount of said coating solution in a predetermined width in m 3 /(m·sec), ρ is an averaged density of said solution in kg/m 3 , g is an acceleration of gravity in m/sec 2 , and α is an angle of the slide surface with respect to horizontal, in °.