Patent ID: 8393293

Claim:
A web treatment tank, which is used in a vertically-oriented feed type, comprising: a side wall; an opening provided in the side wall; and a liquid sealing unit that is provided at the side wall to control leakage of a treatment liquid from the opening, the liquid sealing unit comprising a pair of wall surfaces spaced apart from each other with a predetermined gap therebetween and opposed to each other with a web feed path interposed therebetween, the gap being configured to allow the web to pass continuously in non-contact through the liquid sealing unit, the pair of wall surfaces each having a length in the direction of feed of the web, the length of each wall surface being from 5% to 100% of the length of a slit in the direction of the depth of the treatment tank, the slit being formed by the pair of wall surfaces, wherein the gap between the wall surfaces has a top end and a bottom end, and the gap is narrower at the bottom end than at the top end.