Dispersion - Quartz Presentations Online

“Basic Importance
of
Dispersing & Fine Grinding”
by
Adiwan Djohanli
PT. Kelie Chemical World
Jakarta 23 June 2010

Short biography
• A graduate in Chemistry (B.Sc.) and M.B.A. in Marketing
• Working mostly in Paints / Coatings for more than 30 years in
various positions
• Being: Operator, Supervisor, Chemist, Technical Manager,
General Manager, President Director, Consultant.
• Company: Dulux (ICI) NZ; Raffles Paint, WA Paint& Varnish;
Surface Coatings Australia, Perth, W.A.; PT. Wattyl Dimet
Indonesia; Dimet Malaysia; PT. Akzo Nobel Car Refinishes
Indonesia
• 2005-2007 – Chairman, Indonesian Paint Manufacturers’
Association
• 2006-sekarang – Director / General Manager for PT. Kelie
Chemical World
• Associate Senior Consultant for a Multi national Consulting
Company
• Contributor, writing articles for Asia Pacific Coatings Journal
• Being local agent / representative for ACPS 2010

Dispersion
• Disperser Blade = 1/3 - 1/2
tank diameter
• Batch level = 3 to 5 Blade
Diameters or 1 to 2 tank
diameter
• Tank size = 30 % > batch
volume
• Immersion depth = 1/2 to 2
Blade Diameters from tank
bottom
• Peripheral Speed 22-28
m/s

Type of Blades

Term Definition
• Agglomerates
– Cluster of aggregates
and/or primary particles in
a relatively open selective
compound
Dry pigment agglomerate
• Aggregates
– Firmly attached compound
of primary particles,
– crystals have contact at big
areas
• Primary particles
– Crystalline or amorphous
particles which are
separate from each other
Primary particle
Aggregate

Conventional Dispersion
• Product quality highly
dependent on operator skill
and experience
• Powder feed rate need to be
controlled
• Dispersion blade height
need to be at correct
position
• Dispersion blade speed has
to be adjusted to maintain
VORTEX for optimum
powder wetting
Vortex

High volume dispersion
•Economy of Scale Through Bulk Production
•Reduction of overall production cost through
•Automation:
•Improved Production Capacity
•Reduction of manpower
•Reduction of energy cost
•Consistent & Repeatable Quality Dispersion
•Higher pigmentations - higher yield

Close dispersion system
• Easy cleaning
• No emission, particularly
vacuum feeding
• Specific design:
– minimum batch 25 %
– more intensive mixing
movement in the bottom
zone
• Automatic control - for quick,
efficient solid feeding
• Load cell brackets, batch
control

Automatic Dispersing System
(ADS)

Another dispersion system
• Specific design:
– Agglomerates break up
due to internal air
expansion
• Dosing and disintegration
of solid
• Very fast dispersion
• Easy cleaning
• No emission, particularly
vacuum feeding
• Automatic control - for
quick, efficient solid feeding
• Flexible batch size
• Can handle wide viscosity
range

Kinds of dispersion
Ideal dispersion
Optimised dispersion
agglomerate
5 µ
5 µ
primary
particle
air
agglomerate
liquid
primary
particle
air
solid agglomerate
liquid

Agitator bead mills
12
‣ Horizontal or vertical
construction
‣ The activation of the
grinding beads by an
agitator shaft with pegs,
disks or smooth-shaped
agitating elements
‣ Grinding chamber is filled
with grinding beads
∅ 0,3 – 4 mm to 70 – 90 %
‣ Continuous product flow
through the grinding
chamber
‣ Separation of the
grinding media from the
product at the outlet with
a separation system
Belt drive
Product outlet Grinding chamber
Separation system Product inlet
Grinding disk
Agitator shaft
Motor

Grinding Media
• Size
• 0.1 mm (100 Microns) to 10
mm
• Typical size ranges used are
• 0.6-0.80.8 mm - High quality
liquid inks, Pigment grinding
or Paper coatings, high-tech
ceramics
• 0.8-1.2 mm - Automotive
coatings
• 1.2 - 1.6 -
Industrial/Architectural
coatings, ceramic
slurries/Slips
• Type
• Plastic - SG ~ 1
• Fill
• Glass - SG ~ 2.5
• Ceramics - SG ~ 4 – 6
• Steel - SG ~ 7
• Percent of mill volume filled by
grinding media
• loaded by Volume or weight
• ~ 40 of media volume is free
space

Media Type: Ceramic
• Zirconia-Silica (SAZ)
• True density =
3.85
• Bulk density = 2.3
• Medium
contamination rate
• Low machine wear
• Price: low cost
• Cerium stabilized
zirconium oxide - Zirconox
True density = 6.0
Bulk density = 3.65
Price: medium cost
• Lower cost than
TZP
• Same density
• Higher wear rate
than TZP
• Yttrium Zirconium Oxide
(YTZP) Torayceram
• True density = 6.0
• Bulk density = 3.65
• Medium contamination
rate
• Price: Highest cost
14

Agitator bead mills
Main parts:
- Drive motor
- Shaft speed
- Agitating disc
- Mechanical seal
- Separation system
- Chamber size and material
PERFORMANCE OF MILL

EFFECT OF REDUCTION IN
PARTICLE SIZE
Pigment is a substance, made of particles, almost
insoluble in the application medium, use as
colouring agent or because of it inhibiting corrosion
or magnetic features
The smaller the particles the better is
the colour density of the pigment.
The colour density is the
measurement of the capability of a
pigment to change the colour of
another material
16

Mixing, Pre-Dispersing
Mixing, Predispersing
• Target:
- Production of a homogeneous
suspension
- Disintegration of aggregates /
agglomerates in the shearing area and
uniform distribution in the liquid
- Wetting of the liquids
- De-aeration
A good pre-mixing process
Note
- Facilitates the grinding process
(increase of grinding capacity)
- Reduces the risk of breakdowns
and poor qualities (sedimentation
in the tank and pipeline, blocking
of the separation unit)

Thank you
for
your kind attention
from:
Adiwan Djohanli
PT. Kelie Chemical World
Rukan Gading Bukit Indah F/12, Jl. Bukit Gading Raya,
Jakarta 14240, INDONESIA. Phone / Fax: +62 21 452 2959.
Mobile: +62 811 99 1595. Email: adiwan.djohanli@gmail.com
http://www.linkedin.com/in/adiwandjohanli14250