Abstract: The articles are enclosed in pockets, formed and sealed in plastic windows, of a foldable paperboard blank which has window openings on opposite sides of a fold line, the blank being covered on one surface by a heat-deformable and heat-sealable plastic sheet, at least over that area having the openings or windows formed therein. A blank support, a molding station and a blank discharge station are arranged along a linear blank travel path at substantially equal spacings from each other. A carrier is oscillatable in a vertical plane including the center line of the travel path, and carries air-released vacuum pick-up means at longitudinal spacings substantially equal to the spacings between the support and the stations. The carrier is oscillated between a first position and a second position. In the first position, a first vacuum pick-up means grips a blank on the support and a second vacuum pick-up means grips a blank, which has already been heated and has pockets formed therein, at the molding station.