摘要 |
An efficient, inexpensive, in-line process is provided for producing additive-impregnated corrugated board, such as those having excellent rigid-when-wet and rigid-when-humid strengths. The process comprises applying an additive, such as water- and moisture-resistant resin, flame retardant, fire proofing agent, fungicide, mold-inhibitor, insecticide, or the like, in the form of a collapsible foam of a dispersion or solution of the additive to the corrugated medium, and desirably the liners, at the time the corrugated board is being formed. |