Apparatus and Method for Producing Metal Flakes From the Melt

Abstract

The present invention relates to a method and an apparatus for forming flakes, especially metal flakes. The method comprises producing a heated stream of molten material, feeding the stream in a substantially vertically downward direction, receiving the downwardly directed stream and forming flakes therefrom, and effecting a change in the temperature of the stream subsequent to the production thereof whereby flakes of a desired thickness are obtained. The present invention is applicable to any metal which melts when heated and is capable of being formed into flakes. Examples of metals are Al, Cu, Mo, V, Ag, Cr, Zr, Nb, Ni, Fe, Co, Ti, Au, Pd, W, Hf, Rh, Ir, Pt, Cd or alloys thereof, such as chromium-nickel, iron-nickel, iron-chromium and nickel-cobalt, wherein Cu, Ag, Ti, or Al, or alloys thereof are preferred and Al, or Ag, or alloys thereof are most preferred.

1 . Apparatus for forming flakes, comprising means for producing a heated stream of molten material, means for feeding the stream in a substantially vertically downward direction, means for receiving the downwardly directed stream and for forming flakes therefrom, and means for effecting a change in the temperature of the stream subsequent to the production thereof whereby flakes of a desired thickness are obtained. 
   
   
       2 . Apparatus according to  claim 1 , wherein the means for effecting a change in the temperature are arranged to effect a change of temperature in the stream while it is travelling in a vertically downward direction. 
   
   
       3 . Apparatus according to  claim 1 , wherein the means means for effecting a change in the temperature is arranged to effect a change of temperature in the stream prior to it travelling in a vertically downward direction. 
   
   
       4 . Apparatus according to  claim 1 , wherein the apparatus includes means for applying a high frequency (RF) current, or heat to the vertically downward travelling stream. 
   
   
       5 . Apparatus according to  claim 1 , wherein means are provided for applying an electric current to the vertically downward travelling stream. 
   
   
       6 . Apparatus according to any  claim 1 , wherein the apparatus is provided with means for cooling the stream prior to it being fed in a downward direction. 
   
   
       7 . Apparatus according to  claim 6 , wherein the means for cooling includes a conduit through which the stream is fed, said conduit being surrounded by a cooling coil or jacket through which an appropriate fluid may be fed. 
   
   
       8 . Apparatus according to  claim 1 , wherein the apparatus is provided with mass or volume flow control means in addition or in substitution of the temperature changing means. 
   
   
       9 . A method for forming flakes, comprising producing a heated stream of molten material, feeding the stream in a substantially vertically downward direction, receiving the downwardly directed stream and forming flakes therefrom, and effecting a change in the temperature of the stream subsequent to the production thereof whereby flakes of a desired thickness are obtained. 
   
   
       10 . A method according to  claim 9 , wherein, in addition to effecting a change in the temperature of the stream, or in substitution therefor, a change is effected in the mass or volume flow of the stream. 
   
   
       11 . Flakes obtained by the method according to  claim 9 . 
   
   
       12 . Apparatus according to  claim 1  for forming metal flakes. 
   
   
       13 . A method for forming metal flakes according to  claim 9 . 
   
   
       14 . Metal flakes obtained by the method according to  claim 11 . 
   
   
       15 . Apparatus according to  claim 2 , wherein means are provided for applying an electric current to the vertically downward travelling stream. 
   
   
       16 . Apparatus according to  claim 3 , wherein means are provided for applying an electric current to the vertically downward travelling stream. 
   
   
       17 . Apparatus according to  claim 2 , wherein the apparatus includes means for applying a high frequency (RF) current, or heat to the vertically downward travelling stream. 
   
   
       18 . Apparatus according to  claim 3 , wherein the apparatus includes means for applying a high frequency (RF) current, or heat to the vertically downward travelling stream.