Method for preparing surfaces of carbon fiber-reinforced plastics for further processing into supporting structural parts

Abstract

The invention relates to a method for preparing surfaces of carbon fiber-reinforced plastics for further processing into supporting structural parts of aircraft by abrasive removal of the surface. In order to reduce the risk of cutting fibers during grinding while allowing greater strength of the bond so as to decrease the amount of fashioning to be done, the sand-blasting process is carried out by means of an abrasive that is distributed in dried air. A sharp-edged corundum grain which preferably has a grain size ranging between 0 and 90 m is used as an abrasive.

1 . Method for preparing plastic surfaces, preferably surfaces of carbon fiber reinforced plastics, for further processing to produce supporting structural parts, particularly supporting surfaces of aircraft, by means of abrasive removal of the surface, wherein the material removal takes place by means of an abrasive sandblasting agent that is distributed in a gaseous fluid.  
   
   
       2 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the gaseous fluid is dried air from which oil has been removed.  
   
   
       3 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein a sharp-edged corundum grain, preferably in a grain size range between 0 and 90 μm, particularly between 17 and 62 μm, is used as the sandblasting agent.  
   
   
       4 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the sandblasting agent is applied to the surface to be treated by means of a low-pressure jet, preferably from a pressure boiler at less than 2.5 bar.  
   
   
       5 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the sandblasting agent is applied to the surface to be treated by means of an eddy jet nozzle.  
   
   
       6 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein a treatment with the sandblasting agent takes place as long as necessary in order to achieve an almost cloud-free, matt, treated surface.  
   
   
       7 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the treated surface is blown off with dried and oil-free air, in order to remove the sandblasting agent.  
   
   
       8 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein a quality inspection of the treated surface takes place by means of measuring a surface resistance and/or by means of an optical inspection using a comparison sample.  
   
   
       9 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the treatment takes place in an air-conditioned, preferably draft-free environment.  
   
   
       10 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the surface is vacuum-packed for transport.  
   
   
       11 . Method for preparing plastic surfaces for further processing to produce supporting structural parts, as recited in  claim 1 , wherein the sandblasting agent is not re-circulated.  
   
   
       12 . Semi-finished product, preferably made of carbon fiber reinforced plastic, having a plastic surface prepared for further processing to produce supporting structural parts, particularly supporting surfaces of aircraft, wherein the surface is fashioned by means of a treatment according to  claim 1 , by means of a sandblasting agent distributed in a jet of a gaseous fluid.