| 摘要 |
A method for curtain coating various compositions at high speed onto a continuously moving receiving surface comprises a) forming a composite layer of a plurality of coating compositions having density rho of total volumetric flow rate per unit width Q, forming a freely falling curtain from said composite layer, and impinging said freely falling curtain of height h against a continuously moving receiving surface such that the point of impingement has an application angle theta , b) providing said receiving surface with roughness, Rz(DIN), between about 2 mu m and about 20 mu m, c) providing an electrostatic field at said impingement point whereby high coating speeds can be attained, and d) providing said coating composition forming the layer adjacent to said receiving surface with a viscosity measured at a shear rate of 10,000 s-1 sufficiently high that, when combined with said roughness Rz, said curtain height h, said application angle theta , said total volumetric flow rate per unit width Q, and said liquid density rho , gives a value of specifying parameter phi E that is greater than 1.
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