Basically, the granulation of powders consists in an agglomeration of very fine particles into coarser grains with the help of a binder which keeps unchanged the original properties of the powders.

FOXMET S.A. has developed, during the year 2000, a granulation process that allows its customers to improve the efficiency of their manufacturing processes and, therefore, their competitiveness through:

• a facilitated use of volumetric presses (i.e. excellent flowability of the granules)
• a reduction of broken green parts after cold pressing (i.e. higher “green strengths”)
• the increased lifetime of dies (i.e. wear reduction)
• a reduction of powder segregation (i.e. uniformity of the granules densities)
• an improved diamond distribution (i.e. fewer clusters)
• health improvement for people (i.e. no dust generation during the handling operations)

But, how does the granulation process work ?

The secrecy of a good granulation depends essentially on the choice of the binder and of the granulator.

Indeed, the binder must offer the following properties:

• a good wetting of very fine particles
• a cohesion that is sufficient for handling the granules
• a plasticity that allows to achieve a good “green strength” of the segments after cold compaction
• a total absence of chemical reactions with the metal powders
• a boiling point at a relatively low temperature
• no residues left after evaporation

The process involves:

	The selection of the metal powders, the binder and, eventually, of the diamond grits.
	The careful weighing of the various components that will enter into the composition of the granules and of the segments.
	The mixing of the different components into a suitable blender where particles will be mixed by diffusion, by shear and/or by convection. The blender should avoid particles degradation and should provide with a good reproducibility of the mixtures.
	The equipment must allow continuous production of granules showing a good flowability, similar densities, similar shapes and narrow grain size distributions in order to avoid segregation problems in the manufacturing process of diamond tools.
	The elimination of residual fines through a sieving of the granules at the end of the granulation process.

Grain Sizes Availibity

Remarks:

1. The grain sizes of the granules including diamonds depends on the size distribution of the diamonds.
2. Toll agreements are possible:
   • The toll agreement offered by FOXMET S.A. allows the customers to take profit of all the advantages of the granulation technology without:
   • • investing in expensive equipments
     • spending time in long training sessions
     • following a long and lasting learning curve

   Under this agreement, the customer supplies FOXMET S.A. with its own diamonds and metal powders. In turn, FOXMET S.A. will proceed with the granulation on behalf of the customer.

FOXMET S.A. granulation process is stable, automatic and extremely flexible. It can granulate any batch size.