Method for producing a hollow structural part made of fiber-reinforced plastic

Abstract

For production of a hollow structural part made of fiber-reinforced plastic, a water-dispersible support core made of a water-soluble binding agent consisting at least partly of a water-soluble silicate-containing binding agent, and a filler is wrapped with the reinforcing fibers. The fibers on the support core are impregnated with a curable plastic, the plastic is cured, and the support core is subsequently flushed out with water.

1 . A method for producing a hollow structural part made of fiber-reinforced plastic wherein a water-dispersible support core made of water-soluble binding agent and filler is wrapped with the reinforcing fibers, whereupon the fibers on the support core are impregnated with a curable plastic, the plastic is cured, and the support core is flushed out with water, characterized in that the binding agent consists at least partly of silicatic components. 
   
   
       2 . The method according to  claim 1 , characterized in that the binding agent consists at least partly of water glass. 
   
   
       3 . The method according to  claim 1 , characterized in that the content of binding agent is from 0.5 to 8 wt %, preferably from 0.8 to 4 wt % and particularly preferably from 1 to 2.5 wt %, based on the weight of the filler. 
   
   
       4 . The method according to  claim 2 , characterized in that the binding agent has a SiO 2 /M 2 O weight ratio of from 1.6 to 4.0, in particular from 1.8 to 3.5, where M signifies sodium ions and/or potassium ions and/or lithium ions. 
   
   
       5 . The method according to  claim 1 , characterized in that the binding agent has a solids content of SiO 2  and M 2 O in the range of from 30 to 60 wt %. 
   
   
       6 . The method according to  claim 1 , characterized in that the binding agent consists at least partly of sodium silicate and/or potassium silicate and/or lithium silicate. 
   
   
       7 . The method according to  claim 1 , characterized in that the binding agent contains, besides the water glass, at least one further alkali metal compound. 
   
   
       8 . The method according to  claim 7 , characterized in that the further alkali metal compound is a sodium compound and/or potassium compound. 
   
   
       9 . The method according to  claim 1 , characterized in that the filler consists at least partly of sand. 
   
   
       10 . The method according to  claim 1 , characterized in that the filler consists at least partly of plastic particles. 
   
   
       11 . The method according to  claim 1 , characterized in that the filler consists at least partly of ceramic particles. 
   
   
       12 . The method according to  claim 10 , characterized in that the plastic particles or ceramic particles are of spherical configuration. 
   
   
       13 . The method according to  claim 1 , characterized in that the filler consists at least partly of ceramic or hollow glass spheres. 
   
   
       14 . The method according to  claim 1 , characterized in that it is carried out as a resin transfer molding process. 
   
   
       15 . The method according to  claim 1 , characterized in that it is carried out as a vacuum injection process.