A method for controlling the thickness of a by roll coating film applied to a web

摘要

A paint (P) in a paint pan (12) is picked up through a gap hPA formed between a pickup roll (14) and an applicator roll (16), part of the paint (P) is attached to the applicator roll (16) and delivered to a sheet (S) as a supply flow rate qA. The film thickness coated on the sheet (S) is controlled in accordance with a model equation: M=ä(qA-qL)+/-q+/- Cü/LS which has evaluated a difference between the supply flow rate qA and a leak flow rate qL not transferred onto the sheet (S), remaining on the applicator roll (16) and escaping through a gap hAS (q is the specific gravity of the paint, C the concentration of a solid content of the paint (P) and LS a moving speed of the sheet (S).) Therefore, thickness of a coating film can be controlled at high accuracy over wide ranges of the coating conditions. IMAGE