Process and device for producing moldings, in particular for structural elements, insulations and/or packaging, and moldings so obtained

A process for manufacturing a shaped material comprising the steps of:

• mixing a moist, natural fibrous material with 5 to 85 wt. % of a binder selected form the group consisting of starches, dextrins, pectins, collagens, proteins, and caseins to form a mixture;
• adding to said mixture at least one hydrophobicity increasing agent selected from the group consisting of natural oils, synthetic oils, waxes, fats, resins, rubbers, paraffins, silicones and plastics;
• adjusting a water content of the mixture to 6-25% by weight of the mixture to form an adjusted mixture;
• compacting and applying shear forces to the adjusted mixture in a screw extruder to increase pressure and temperature until the binder melts to form a molten gel mixture;
• shaping the molten gel mixture by passing the mixture through a shaped-imparting nozzle attached to the extruder;
• and
• relieving pressure from the molten gel mixture immediately thereafter such that as moisture in the molten gel mixture turns to steam, spontaneous expansion of the molten gel mixture occurs and a structurally rigid, fiber or chip-based shaped part is formed which has a density lower than the overall density of the non-gaseous components of which it is made up but a relatively dense surface.

A process for manufacturing a material for use in structural elements, insulation and packaging comprising the steps of:

• mixing a moist, natural, fibrous material and a binder together, wherein the binder is selected from the group consisting of starches, dextrins, pectins, collagens, proteins, and caseins to form a mixture;
• adjusting a water content of the mixture to 6-25% by weight of the mixture to form an adjusted mixture;
• compacting and applying shear forces to the adjusted mixture in a screw extruder to increase pressure and temperature until the binder melts to form a molten gel mixture;
• shaping the molten gel mixture by passing the mixture through a shape-imparting nozzle attached to the extruder;
• relieving pressure from the molten gel mixture immediately thereafter such that as moisture in the molten gel mixture turns to steam, spontaneous expansion of the molten gel mixture occurs and a fiber or chip-based shaped part is formed which has a density lower than the overall density of the non-gaseous components of which it is made up but a relatively dense surface;
• and
• coating the molten gel mixture with a peripherally supplied coating mass before the molten gel mixture is passed through the nozzle.