Method for spraying chemical solution

Abstract

[Problem] To provide a method for spraying a chemical solution, including: spraying the chemical solution onto a surface of a dryer roller with a nozzle device reciprocated in the width direction of the dryer roller rotating at a high speed, whereby a sufficient amount of the chemical solution can be remained on the surface of the dryer roller. [Solution] The present invention is directed to a method for spraying a chemical solution, including: spraying the chemical solution onto a dryer roller by two nozzle devices disposed at a certain interval therebetween with the two nozzle devices each reciprocated along a rail extended in the width direction of the dryer roller, in a state that the dryer roller, for guiding wet paper, is being rotated, in a dry part of a paper-making machine, wherein a time T required for the two nozzle devices each to travel one-way is set as 0.2 to 1.5 minutes; a rotational speed Vd of the dryer roller is set as not less than 100 times/min; the number of contacts N that a point Q on the dryer roller surface makes contact with the wet paper during the time T is set as 30 to 250 times; the time T, the rotational speed Vd, and the number of contacts N satisfy the relationship of N=T*Vd; and the total amount of the sprayed chemical solution is set as 0.3 to 500 mg/m2 as an effective component amount.

Dependencies are inferred from the claim text.