Method of and apparatus for controlling application of glue to defined

Abstract

Apparatus for applying adhesive onto flutes of single facers of corrugated media, so that the single facers may be adhered together and to a facing to form a composite web, comprises a plurality of adhesive applicator rolls, each for applying adhesive to the flutes of an associated one of the single facers. The actual speed of travel of the single facers passing across the applicator roll peripheries is sensed, and the rate of rotation of each roll is independently and accurately controlled, in accordance with the sensed speed, to apply a desired amount of adhesive onto selected areas of the flutes. The independent accurate control over applicator roll speeds enables minimum amounts of adhesive to be applied onto the flutes of the individual single spacers, as determined by their configurations and consistencies, while still ensuring proper adhesive of the single facers one to the other ad to the facing. Applying minimum amounts of adhesive onto the flutes reduces both the amount of adhesive required and moisture added to the single facers, so less heat is required to set the adhesive. In addition, minimizing moisture added to the single facers substantially eliminates warping of the composite web and 'ribbing' on its outer surfaces, so the surfaces are very smooth and very high quality printing and graphics may be applied onto the surfaces.