Abstract: Paperboard is produced by chopping or mincing waste paper the particles of which are fed through a mixer which can blend the particles with particles of different composition or color after which the particles are laid down into a uniform layer to form a mat which is sprayed with water. The entire mat is then subjected to a uniform compression from anywhere from between 300 to 500 kg/cm2. Alternatively, at least two such layers of paper particles are separated by a water film and are then compressed into a mat so that the water is forced to the outside of the mat through the layers.

Abstract: A method and a production plant for production of sheets with substantially stiff structure of paper material comprise the steps of paper grinding to obtain paper flakes, spreading the flakes to obtain a carpet of flakes, sprinkling the carpet with gluing liquid, accomplishing a first compacting of the flakes and accomplishing a second compacting of the carpet during which is executed a simultaneous forming to obtain a sheet with a plurality of stiffening dishes.

Abstract: A method of making a substantially lattice-like composite material having a large percentage of open spaces comprises the steps of disposing generally elongate and flexible strips in a randomly-oriented chaotic mass; atomizing a liquid bonding substance into the mass; carrying out a mass-forming process involving volume reduction to make a lattice-like structure of a large percentage of open spaces, in a desired shape; hardening the bonding substance. Thus a substantially lattice-like material having a high percentage of open spaces is achieved, which is formed of a plurality of generally elongate and flexible strips disposed in a randonly-oriented chaotic mass, the strips being bonded to each other at discrete points in the mass. This material can be manufactured to advantage starting from waste materials, such as paper and wood chips, and it can be formed into sheets and panels of flat shape or of different conformations to make packages and the like.