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How to avoid doughnut or donut shaped granules?

By using Freeze Granulation – Spray Freeze Drying – you will be able to avoid donut-shaped granules.

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.

Granule shape, size and density

Spherical granules by freeze granulation
Spherical granules by freeze granulation

Freeze Granulation provides spherical free-flowing dust-free granules without cavities in the size range of 20-500 micron. The solids content of the suspension (slip) and the processing parameters (pump speed and airflow) control the granule density and size.

 

 

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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.

Granule homogeneity

Migration and segregation of the constituents that is common in other granulating processes such as spray drying is avoided in Freeze Granulation. By instant freezing of small droplets critical ice crystal growth is avoided. The freeze drying where the liquid medium is sublimated ensures homogeneity preservation, limited oxidation and soft bonds within the granules. This provides the best possible condition for any subsequent processing such as easy pressing to homogenous compacts, easy re-dispersing in a liquid, sintering of catalytic particles, dosage processes etc.

Thermal spraying

Homogeneous thermal spray powders, for forming thermal spray coatings, can be made by Freeze Granulation. The homogeneity of the spray powders is very important, not only for composite spray powders and by using FG you will keep the homogeneity throughout the process.

Utilization of Freeze Granulation for different applications

Freeze granulation can be utilized on lab scale as well on production scale with equality in granule properties and high yield for many applications. Besides large quantities also very small experimental batches (50-100 ml slip) can easily be processed. The equipment is easy to clean, enabling use of water insoluble polymers (latexes) as binder and running of several different batches during one day. Water is the preferred liquid medium but it is also possible to use and recycle organic solvents (freeze point > -25°C).

Lab-scale granulator - LS-2
Lab-scale granulator - LS-2

Technical specification lab-scale freeze granulator (LS-2)

PowderPro AB provides equipment for Freeze Granulation in two versions, LS-2 (see photo) and LS-6. The maximum granulation capacity of LS-2 is 2 litres slurry per hour and for LS-6 6 litres slurry per hours that typically correspond to ca 2 and 6 kg dry powder respectively.

LS-2 and LS-6 consists of a slip container with a stirrer, a pump for the slip, a spray nozzle, a regulator for compressed air and an insulated chamber for spraying and granule collection. Technical Specification LS-2

Besides the granulator, a freeze dryer (see photo of Lyovac GT2 below) with sufficient capacity is required and can be provided. Technical transfer including set-up of equip­ment and training of personnel is recomm­ended and offered upon request.

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.

Equipment for agglomeration of fine powders
Lab-scale freeze granulator LS-2

 

Freeze dryer Lyovac GT2

 

 

 

 

 

 

 

 

Technical specification GT2:  Freeze-Dryer-Drying-Vacuum-Lyophilizer-LYO-GT2-Overview–Product-Information-2010v01

A kind of spray dryer that make homogeneous granules – Freeze Granulator

A Freeze Granulator is a kind of spray dryer that produces homogeneous granules, see photo below showing a cross section of a granule with no defects; no pores, no inhomogeneities like agglomerates or migration of fines or binders.

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.

Cross section of ganule
Cross section of ganule

Continuous granulation of powders and chemicals

Continuous granulation of powders and chemicals by Freeze Granulation. At PowderPro we are currently developing a new production granulator for continous granulation of powders and chemicals with a capacity of 50-100 kg/shift.

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.

Questionnaire for test of freeze granulation

If you would like to make a test-granulation, please download and fill in our Questionnaire for test of freeze granulation and email it to us and contact us if you have any questions.

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 granulation vs spray drying
Freeze granulation vs spray drying

Deagglomeration of nanoparticles and other submicron powders

By applying Freeze Granulation on your agglomerated nanoparticles or submicron powders you will be able to deagglomerate them forming a homogeneous well-dispersed particles or mixture of particles.

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.

Processing of nanoparticles
Processing of nanoparticles