| 摘要 |
#CMT# #/CMT# Production of sandwich panels with a honeycomb core (12) enclosed on both sides, at least one side being closed by a fiber composite layer (14) comprises: (A) forming a sandwich consisting of the core and, on at least one side, from the inside outwards, a curable adhesive (20), a barrier layer (16) and a fiber layer (14); (B) placing this in an open mold which is then sealed with a vacuum film and evacuated; (C) curing the adhesive under vacuum, so that the cells (18) of the honeycomb are partially evacuated before they are sealed by the barrier layer; and (D) infusing the fibers (24) with matrix material (26) which is then cured. #CMT# : #/CMT# An independent claim is included for sandwich panels produced using the method in which the fiber composite layers have a pore volume of 2% and the panel has a minimum tensile strength, at right angles to the layers, of 3MPa. #CMT#USE : #/CMT# In the air and space industries, ships, rail and road vehicles. #CMT#DESCRIPTION OF DRAWINGS : #/CMT# The drawing shows a cross-section of the sandwich panel. 12 : Honeycomb core 14 : Fiber composite layer 16 : Barrier sheets 18 : Cell in honeycomb 20 : Curable adhesive layers 24 : Fibers 26 : Matrix #CMT#POLYMERS : #/CMT# Preferred features: The sandwich is covered with a gas-permeable, microporous membrane, which is impermeable to matrix material, during curing of the adhesive. The fiber layer is soaked in liquid matrix material or films of the material are applied to it. The barrier layer is a film which has been plasma- or corona-treated and/or coated. The dwell time and/or rate of heating of the sandwich in the mold are adjusted to produce a vacuum in the cells approaching that in the mold, before the adhesive has cured. A vacuum of 10 mbar or less, especially 1 mbar or less, is used. |
