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How to make granules from powders

Homogeneous Granules by Freeze Granulation

By using Freeze Granulation or Spray Freeze Drying it’s possible to make spherical, homogeneous and dust-free granules with optimal flowability which is critical for automatic uniaxial pressing of for ex ceramics and metal powders.

You can expect spherical and homogenous granules of powders in terms of distribution of particle size  and other possible additives you want to use. The granules with a size distribution in the range of 50-300 microns will have weak inter particle bonding making them easy to break down in pressing or re-disperse into another formulation. Very much depend upon how you intend to process the powder and depending on that, adaptation can be made.

Please contact us and we will further discuss the opportunities with Freeze Granulation on your powder system and read more on technology and we propose a Granulation Test of your powder system.

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Nano Diamond Powder

Freeze Granulation is today being used for mixing, granulation and drying of nano diamond powders. The resulting granules have a homogeneous distribution of nano diamond particles, fillers, binders and nano pores. Please go to Contact and ask for more information and for a Test-Granulation.

 

Processing of nanoparticles
Processing of nanoparticles

Preparation of PIM or Extrusion Feedstock

Freeze Granulation of PIM or Extrusion Feedstock

Powder injection molding (PIM) and extrusion are powder shaping techniques that typically involve preparation of high viscous feedstock making it difficult to achieve full homogeneity. Especially if the powders are fine (submicron or nano) and/or if it is a composite material. By doing an initial preparation of a low viscous (based on water or organic) suspension the powders can be properly de-agglomerated, dispersed and homogenized. Other constituents aimed for the PIM or extrusion process can be added prior to freeze granulation. The result will be a homogenized, soft and dust free powder, easy to mix and disperse into a feedstock for PIM or extrusion at high powder concentration and homogeneity, promoting sintering and ultimate material performance.

Please contact us for more information and a test-granulation of your powder system.

Superabrasive grinding tools

Homogeneous superabrasive grinding tools by Freeze Granulation

Freeze Granulation is today being used for the production of high quality superabrasive grinding tools, where the superabrasive grains are homogeneously distributed in the grinding tool. This results in a grinding wheel with higher grinding capacity and longer grinding and cutting tool life.

Please contact us for more information and a test-granulation of your powder system.

Freeze granulated diamond composite granule
Freeze granulated superabrasive grinding granules

Wet granulation

Freeze Granulation – homogeneous wet granulation of powders

Freeze Granulation is a wet granulation method where the powders, chemicals and binders are first mixed and dispersed in a solvent. In the next step the homogeneous slurry is pumped and sprayed through a nozzle to form droplets, which are sprayed into liquid nitrogen for instant freezing. In the final step the frozen granulate is moved to a freeze dryer where the solvent is sublimated leaving spherical, dust-free and homogeneous granules. The solvent could be water or organic solvents with a freezing point close to zero degree, like cyclohexane.

Please contact us for more information and a test-granulation of your powder system.

Diamond composite granules
Spherical, dust-free, homogeneous granules – no donuts!
LS-2 – Lab-scale Freeze Granulator

 

Nano ice formation in granules

Nano ice in granules by Freeze Granulation

The formation of nano ice in the Freeze Granulation process is a key factor for the unique homogeneity of particles and binders achieved in the resulting granules. This is especially important for nanopowders, fine particles and binders where migration of these could occur during conventional drying, like spray drying.

Please contact us for more information and a test-granulation of your powder system.

Nano ice formation in granule
Cross section of homogeneous nano ice in granules

Granulation equipment

PowderPro supplies equipment for granulation of various powders and chemicals. Freeze Granulation for improved granule properties compared with spray drying. Granules with no void formation, no migration of fine particles or binders, and no formation of hard dry shell.

Spray cooling or rather called spray freezing is the first step in the freeze granulation process where a suspension is atomized, sprayed with a nozzle, into a chamber with liquid nitrogen. The small droplets are then rapidly frozen with a minimum of ice crystal growth. The frozen material (granules) are then transferred to a freeze dryer/lyophilizer where the ice is removed by sublimation, i e never go through a liquid state that ensure homogeneity preservation.

Please contact us for more information or if you have specific questions on your system and for a test-granulation of your powder system.

Transparent and translucent ceramics

Transparent and translucent ceramics by Freeze Granulation

Freeze Granulation is today being used for commercial manufacturing of transparent and translucent ceramics. The main advantage is to achieve a homogeneous distribution of the starting material which will result in rapid reaction and sintering at low temperature where grain growth of the material will be avoided.

Please contact us and we will further discuss the opportunities with Freeze Granulation on your powder system and read more on technology and we propose a Granulation Test of your powder system.

Freeze drying

Spray Freeze Drying for Soft Granules by Freeze Granulation

Freeze drying is an important processing step in Freeze Granulation where we sublimate the solvent (ice if water) from our spray frozen (spray freezed) granules, resulting in a free-flowing and dust-free granulated material suitable for pressing of components.

Please contact us for more information and a test-granulation of your powder system.

 

Freeze dryer Lyovac GT-2