| 摘要 |
The invention relates to a method for producing sandwich construction elements for substantially load-bearing and self-supporting building parts. In order to produce a sandwich element which is suitable for self-supporting and substantially load-bearing building parts, since it ensures the necessary transmission of the compressive, tensile and shear forces between the cover layer and core layer and meets the increased fire-protection requirements, the production method proposed contains the following steps: a) producing at least one layer of a mechanically bonded fiber nonwoven which is impregnated with a binder based on at least one heat-curable resin system, and is itself based on naturally occurring raw materials, in particular hemp, flax, jute, sisal, kenaf, cotton and wool and/or mixtures thereof, b) curing the heat-curable resin system in order to produce at least one hardened layer of the fiber nonwoven, wherein, before and/or during the curing operation, a surface structure is applied to at least part of the layer of the fiber nonwoven and/or at least one further binder based on at least one heat-curable resin system is applied to at least part of the surface of the hardened layer of the fiber nonwoven, and fixed thermally, c) bringing a heat-foamable or heat-foamed phenol resin into contact with that surface of at least one hardened layer of the fiber nonwoven which has been modified according to step b), d) possibly annealing, at temperatures ranging from 40 to 80° C., the composite produced in a) to c), and e) curing the further binder based on at least one heat-curable resin system, and possibly applied in b), at a temperature ranging from 150 to 200° C., possibly under elevated pressure.
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