|
Problem: |
Solution: |
|
Lumps or
oversized Particles Excess
product moisture Excess
partial product moisture Too sticky
polymer Too high
local binder concentration |
Lumps or
oversized Particles Lower the
spraying rate Increase
inlet air and product temperatures Increase
atomizing and microclimate pressure Increase
process air flow Check
function of the spraying nozzle O-rings Liquid tip,
spray air tip |
|
Fines Insufficient product moisture Insufficient local product moisture Instable granules Mechanical Impact Too low local binder concentration |
Fines Decrease product temperature Decrease inlet air volume Shorter drying time Lower atomizing and microclimate pressure More appropriate binder Increased binder amounts Higher binder concentration in solution Reduce possible spray drying effect |
|
Width
particle size distribution Excess
product moisture Excess local
product moisture Instable
granules Mechanical
impact Inhomogeneous
granulation (Product falls after the granulation from the dome or filter) |
Wide
particle size distribution Lower or
increase spraying rate Adjust inlet
air and product temperatures Adjust
product temperatures Adjust
atomizing and microclimate pressure Check
function of the spraying nozzle Decrease the
friability of the granules |
|
Powder layer at the dome and filters Recondensation Electrostatics and bad flowability Particle size of the starting material Too fine granules |
Powder layer at the dome and filters Pre-heating of the fluid bed Adding more water to the spraying liquid Lower inlet air temperature Reduce-spraying rate at beginning Adding of Aerosil to powder mixture before charging Increase microclimate (effect of spray drying) Increase granulation effect Increase inlet air amount in final phase of discharge step |
|
Low yield with clean dome and filters Broken sealing at the filters Damages at the filter socks Starting material is passing the
filters |
Low yield with clean dome and filters Replace Sealing Replace filter socks, do not repair Use filter socks with Teflon membrane
(pore size ~ 1 µm) |
|
Low density of the product Pre-Milling of the starting material Pre-movement of the starting material in the fluid bed Very high product moisture content Prewetting of powder before start of binder application Transfer to RMG |
Low
spraying rate Reduce
the binder concentration Increase
the hose size Pre-pressure
on binder vessel Heat
up the spraying liquid |
|
No sufficient air supplies Shorten cleaning cycle Increase cleaning pressure Granulate faster Decrease the air amount |
|
|
Segregation of the product Charge with low inlet air Change excipients (particle size) Start charging good flowable powders Pre-granulate small particles |
|
|
Inhomogeneity of low-quantity ingredients |
Add
the ingredient to the granulation liquid |
|
Lumps or oversized Particles in the
RMG Excess Product moisture Excess partial product moisture Too excessive granulation |
Lumps or oversized Particles Lower spraying rate Increase spraying rate Use the chopper Decrease the liquid amount Faster agitator speed during liquid
adding Slower agitator speed during
granulation Shorter granulation time Add the liquid by using an atomizing
nozzle |
|
Fines Insufficient product moisture Instable granules Insufficient granulation |
Fines Increase spraying rate Increase the liquid amount Faster agitator speed Increase granulation time Inappropriate binder Insufficient binder amounts |
|
Segregation
in the RMG |
Adjust the
agitator speed Adjust
mixing time Add the
ingredient after wetting |
|
Blockage of the Wet Mill Wrong set up of the mill Product flow to the mill |
Blockage of the Wet Mill Increase speed of knife Use wider mesh size Use sieve with square holes Use round knife Decrease the agitator speed during discharge |
