RECYCLING OF COATED PAPERBOARD

摘要

A process for the separation of cellulosic fibres from coated paperboard is disclosed. The coated paperboard is disclosed. The coated paperboard is comprised of at least one layer of cellulosic fibres coated on at least one side with at least one of thermoplastic polymer and metallic foil. The process comprises pulping the coated paperboard in aqueous solution in a pulper vessel (2), the pulper vessel (2) having rotating knives (3) in the bottom thereof effective for the pulping of said paperboard to form a suspension of cellulosic fibres in the aqueous solution. In a first embodiment the solution has a surface within the vessel (2). A fraction (56) comprised of thermoplastic polymer and/or metallic foil is separated from the surface of the aqueous solution in the pulper vessel (2). The process permits separation and recovery, especially for recycling, of the components of coated paperboard e.g. beverage containers. In a second embodiment the solution from the vessel (2) is continuously passed to a coarse screen (12) having a mesh size to effect separation of a substantial portion of the thermoplastic polymer and metallic foil, the solution with the cellulosic fibres passing through the screen (12). The solution with the cellulosic fibres is then subjected to cleaning by using hydrocyclone cleaners (21, 25) adapted for rejection of material heavier and lighter than cellulosic fibres respectively. Finally the cellulosic fibres are separated from the cleaned solution in a separator (27).