A corrugated paperboard strength enhancing process includes at least one resin application station located within the confines of the corrugator at a position where it is operable to apply a preselected amount of strength enhancing resin to at least one side of the medium after it has been fluted and most preferably before adhesive has been applied to the medium for securing liner paper thereto. At least one liner is adhered to the set of opposed flute tips. Thereafter the combined board with the resin compound on selected transverse portions of the fluted medium is allowed to cure, under selected temperature and moisture conditions and without the application of pressure that would crush the fluted medium. A suitable resin for the intended purpose is an isocyanate compound. The strength-enhanced corrugated paperboard can be efficiently repulped.