Patent ID: 9587393
Date: 2017-03-07
CPC Classifications: B29C,B29K,B32B,C08J,E04B,E04C,Y10T

Claim:
1. A method for producing sandwich construction elements for essentially loadbearing and self-supporting parts of a building, said method comprising the steps of a) producing one or more than one ply of a mechanically consolidated fibrous fleece based on naturally occurring raw materials selected from the group consisting of hemp, flax, jute, sisal, kenaf, cotton, wool, and mixtures thereof, each ply impregnated with a binder based on one or more than one heat-curable resin system, b) curing the heat-curable resin system to produce one or more than one cured ply of the fibrous fleece, applying a surface structure to at least part of each ply of the fibrous fleece before and/or during curing; and/or applying and thermally fixing one or more than one further binder based on one or more than one heat-curable resin system to at least part of a surface of the cured ply of the fibrous fleece, c) contacting a thermally foamable or foamed phenolic resin with the surface, as modified in step b), of one or more than one cured ply of the fibrous fleece, d) optionally subjecting the composite produced under a) to c) to conditioning at temperatures in a range from 40 to 80° C., and e) if applied, subjecting the further binder based on one or more than one heat-curable resin system and optionally applied in b) to curing in a range from 150 to 200° C., optionally under elevated pressure.