A conveyor of a cardboard-folding station receives a cardboard blank having a first portion, first and second lateral closing walls hinged thereto and facing upstream and downstream, respectively, an upper closing wall hinged to the second lateral closing wall and facing downstream, a third and a fourth lateral closing wall hinged and partly raised with respect to the first portion and projecting from sides of the conveyor. An article rests on the first portion, with four flanks or the article respectively facing the four lateral closing walls of the blank. At a first folding zone the third and fourth lateral closing walls are folded to cover the third and the fourth flanks of the article, and at a second folding zone the second lateral closing wall and the upper closing wall are folded to cover the article's second flank and its upper face.