Mfg. sandwich plate - comprises wetting long sides of core only for glue bonding of cover plates to retain core strength

摘要

For the manufacture of a sandwich panel, a core is formed from strips of fibre-containing material such as cardboard or paper, the breadthwise direction of which strips coincides with the thickness direction of the panel, and a covering sheet is subsequently bonded to each of the longitudinal sides of the core. In order to improve this bond, after the core is formed, at least one of its longitudinal sides is treated with a liquid for softening the edges of the strips at that side, following which the strips are exposed to a pressure force in the thickness direction of the panel, for upsetting each moistened edge, and an adhesive is applied to each edge thus upset, for the purpose of fixing a covering sheet thereon. The device used here comprises two moistening elements, together forming a nip through which the core can be conveyed, at such speed that sufficient moisture can be taken up for moistening the edges at the longitudinal sides of the core, while the central part of the core remains dry.