Method and additive for dry coalescing and kneading powders, for the exfoliation thereof

Abstract

The present invention relates to a method for dry coalescing and kneading powders, for the exfoliation thereof, comprising the steps of providing a polytetrafluoro-ethylene aqueous suspension or emulsion, stirring to flocculate the emulsion, fully drying the emulsion and dispersing the obtained concentrated material through the powders to be processed.

1 . A method for dry coalescing and kneading powders, for an exfoliation thereof, characterized in that said method comprises the steps of providing an aqueous polytetrafluoro-ethylene suspension or emulsion, stirring said emulsion to flocculate said emulsion, fully drying said flocculated emulsion and dispersing a concentrated material obtained therefrom through said powders.  
     
     
         2 . A method, according to  claim 1 , characterized in that said powders have a particle size range from 1 micron to 3 mm.  
     
     
         3 . A method, according to  claim 1 , characterized in that said stirring step is a rotary, stirring step.  
     
     
         4 . A method, according to  claim 3 , characterized in that said rotary stirring step is carried out at a stirring rate up to a maximum of 2500 rpm's.  
     
     
         5 . A method, according to  claim 1 , characterized in that said concentrated material is mixed in an amount of 0.2% to 30%.  
     
     
         6 . A method, according to  claim 1 , characterized in that said method comprises a further kneading step and an optional laminating exfoliation step.  
     
     
         7 . An additive for dry coalescing and kneading powder materials, characterized in that said additive comprises an aqueous polytetrafluoro ethylene suspension or emulsion.  
     
     
         8 . An additive, according to  claim 7 , characterized in that said additive comprises an aqueous suspension or emulsion polymer including polytetrafluoro-ethylene with a water dilution depending on aggregating and absorbing characteristics of said powders said additive is applied to.  
     
     
         9 . An additive, according to  claim 7 , characterized in that, to provide an optimum flocculation of said polytetrafluoro-ethylene in said suspension or emulsion, said additive is rotatively stirred at 2500 rpm's.  
     
     
         10 . An additive, according to  claim 9 , characterized in that said additive is flocculated by controlling a clearness of a filtrate material thereof.  
     
     
         11 . An additive, according to  claim 7 , characterized in that said additive is provided in a filtered and dry form.  
     
     
         12 . An additive, according to  claim 7 , characterized in that said additive comprises a polymer amount depending on a cohesion capability to be provided to said powders.  
     
     
         13 . An additive, according to  claim 12 , characterized in that said polymer amount is from 0.2% to 30% of said powders.  
     
     
         14 . An additive, according to  claim 7 , characterized in that in said additive said powder dispersed concentrate has been subjected to a further kneading step, to render said additive suitable for an optional lamination step.