Method for adjusting coating weight by gas wiping

• Main Authors: ANDACHI; KAZUNARI, SHIGEMOTO; HARUMI
• Format: Patent
• Language: English
• Published: 21.05.1996
• Edition: 6
• Subjects: APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CHEMICAL SURFACE TREATMENT; CHEMISTRY; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATIONOR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY IONIMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; COATING MATERIAL WITH METALLIC MATERIAL; COATING METALLIC MATERIAL; DIFFUSION TREATMENT OF METALLIC MATERIAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION INGENERAL; METALLURGY; PERFORMING OPERATIONS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; SPRAYING OR ATOMISING IN GENERAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THESURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; TRANSPORTING

PCT No. PCT/JP93/00555 Sec. 371 Date Dec. 13, 1994 Sec. 102(e) Date Dec. 13, 1994 PCT Filed Apr. 28, 1993 PCT Pub. No. WO94/05179 PCT Pub. Date Oct. 11, 1994.A method of adjusting coating weight of a coating material with high accuracy within a wide range of operation, by setting and using a relational formula for determining a coating weight W of the coating material separately in accordance with relative relation between a nozzle-strip distance D and a nozzle slit clearance B. The adjustment of the coating weight of molten metal (coating material) is performed by controlling a nozzle pressure P and a strip speed V, and also by controlling D by equation (1) in the range of D/B</=C (developing range) and at least one of D and B by equation (2) in the range of D/B>C (fully developed range). ( rho M=molten metal density, mu =molten metal viscosity, PA=pressure at nozzle outlet, eta =nozzle efficiency, K=ratio of specific heat of gas, and h1 and h2=constants) W=h1x rho Mx{(K-1)/(2x eta xKxPA)}1/2xD1/2x[ mu xV/{(P/PA)(K-1)/K-1}]1/2(1) W=h2x rho Mx{(K-1)/(2x eta xKxPA)}1/2x(D/B1/2)x[ mu xV/{(P/PA)(K-1)/K-1}]1/2(2)