ＮNISSHIN SEIFUN

The Latest Size Reduction Technology
For Color & Monochrome Toners
byDr. Satoshi Akiyama
Manager
Nisshin Seifun Group Inc.
Dr. Carl K. Ishito
General Manager
Nisshin Engineering Inc.

Ｎ

1st Asia Imaging
Forum 2006 inKuala Lumpur,Malaysia
Place: Sunway Lagoon Hotel
Date: June 30, 2006 (Fri.)
Organizer: AIF

NISSHIN SEIFUN

Content• Trends in particle characteristics of toners• Market size and growth• Improvement of grinding and classification
processes• New mechanical mill system for monochrometoners• New jet mill system for color toners• Future outlook1ＮNISSHIN SEIFUN

Trends in particle characteristics of toners
・ Particle size
Smaller ( 5〜6µm )・ Particle size distribution
Narrower( Less fine particles & coarse particles )・ Particle shape control
Spherical or round particles

Conventional
pulverized toner

NISSHIN SEIFUN

140,000

Production in Japan [ton]Ｎ

Chemical toner

120,000

ChemicalPulverized

100,000
80,00060,00040,00020,00002001 2002 2003 2004 2005 2006 2007 2008

Year

Production of chemical toner andpulverized toner in Japan

2

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Revenue in billions of US$

25.00

Color
Monochrome

20.00

15.00

10.00

5.00

0.002000 2001 2002 2003 2004 2005 2006 2007

Year

Worldwide bulk toner revenue

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Raw Material
Mixer

MixingExtruderMulling

CrusherCoarse grinding

Pulverizer

Fine grinding

Classifier

Coarse Classifying

Classifier

Fine Classifying

SiO2
Mixer

MixingProduct

Process flow of grinding toners

3

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110100
Diameter[μm]10110100
Diameter[μm]100 1000
Diameter[μm]CycloneBag house

Raw material

Bag house

Classifier

FeederBlowerCycloneMechanicalmillClassifier

BlowerAir cooler
Product110100
Diameter[μm]110100
Diameter[μm]110100
Diameter[μm]Flowsheet of grinding and classifying process for toner

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LinerRotorRotor
Liner

Cross-sectional View

Mechanical mill; Super Rotor SR-254ＮNISSHIN SEIFUNClassification Rotor
Dispersion Blades

Powder Feed

Dispersion DiscClassification Blades
Coarse Fraction
OutletAir
Auxiliary Blades
Scroll Casing
Balance Rotor
Air Flow

Cross-sectional view of Turbo Classifier

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Centrifugal Force

Large Particles
Centrifugal Force ＞ Drag Force

Air Flow
Drag Force

Small Particles
Centrifugal Force ＜ Drag Force

Particle Rotation

Principle of air classification(centrifugal force classification)5NISSHIN SEIFUN

Fine particles less than 5µm [vol.%]

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Closed circuit system

24
Mechanical mill
Jet mill

20
16

Magnetic toner withstyrene-acrylic resin

12840678
9 10 11 12 13Median diameter [µm]Relation between the median diameter of product andthe volume percentage of fine particles less than 5µm

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100

Product yield [%]

Ｎ90

80

Mechanical mill
Jet mill

70

Magnetic toner withstyrene-acrylic resin

606789 10 11 12Median diameter [µm]13Relation between the median diameter and productyield in grinding and classifying process

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Specific energy consumption [kW h/kg]

Ｎ

7
Closed circuit system

6Mechanical mill
Jet mill

54321

Magnetic toner withstyrene-acrylic resin

06789 10 11 12Median diameter [µm]13Relation between the median diameter of product andspecific energy consumption of closed circuit grinding system

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14Median diameter [µm]Ｎ

Styrene-acrylic toner
Polyester toner
12108

Mechanical mill
without classifier

611,000
12,00013,000
Rotational speed [min-1]

Relation between the rotational speed of mechanical mill andthe median diameter of product ground with mechanical mill

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Temperature control for mechanical millMethods
Inlet air temperature: from +5 to -40 degree C(from 41 to -40 degree F)
Cooling rotor: waterConditions
Feed Material: Non-magneticToner with Polyester Resin,
D50=500µm
Grinding Mill : Mechanical Mill
Product Diameter: 8 µm
Temp. of Mill Outlet: 50 degree C (122 degree F)

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20

Maximum throughput [kg/h]

Ｎ

Closed circuit systemwith mechanical mill
151050-50Polyester toner

10-40 -30 -20 -10 0
Temperature of cooling air [ C]O

Relation between the temperature of cooling air andthe maximum throughput of the mechanical grinding system

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Specific energy consumption [kW h/kg]

Ｎ108

Closed circuit systemwith mechanical mill

64
20-50

Polyester toner-40 -30 -20 -100 10
Temperature of cooling air [ C]O

Relation between temperature of cooling air and specific energy
consumption of closed mechanical grinding system

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Product

Water
Feed(Powder)
Water

Structure of cooling rotor

Super Rotor using cooling rotor

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Maximum throughput [kg/h]Ｎ

12
Conventional rotor
Cooling rotor

108642Polyester toner

0
8,000

10,00012,00014,000

Rotational speed [min-1]

Effect of cooling rotor on throughput ofmechanical mill

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NISSHIN SEIFUN

Particle shape measurement
Particle shape analyzer
Malvern ; FPIA-2000( Flow Particle Image Analyzer )Perimeter

Definition of shape factor
Circularity index( C.I .)√(4π*Area)=Perimeter≦ 1

Smooth & round surface shapeArea

1 (Spherical shape)

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10µm

10µm10µm

C.I. = 0.93

C.I. = 0.93

C.I. = 0.94(a) Target jet mill(b) Pancake jet mill(c) Mechanical millEffect of type of mills on particle
shape of monochrome toners

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Toner manufacturing plant using the mechanical mill

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New jet mill; Super Jet mill for color toners
Features¾Narrow particle size distribution,less fine particles & coarse particles¾Simple inner structure without moving partsless powder accumulation and adhesion¾Easy maintenance and cleaning

Super Jet mill SJ-10K

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Grinding zone
(1st stage classifying)

Grinding nozzle
OutletInlet
Comp.airClassifying zone
Classifying ring

(2st stage classifying)

Structure of Super Jet Mill

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Conventional
jet mill

Super Jet Mill

Relation between particle size distribution ofproduct and mixture ratio (color toner)

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Conventional jet millSuper Jet MillSEM photos of color toners ( D50=7µm )13ＮNISSHIN SEIFUN(1) Screw feeder(1) Screw feeder(4) Bag house(2) Mechanical Mill (5) Classifier(3) Cyclone(6) Blower(4)(2) Super Jet Mill
(3) Cyclone(4) Bag house

(4)
(4)

(5)

(3)

(1)
(1)
(6)
(3)

(6)

(3)

(2)
(2)

Closed circuit grinding systemof mechanical mill

Grinding system ofSuper Jet Mill

Flowsheets of two kinds of grinding system

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Relation between the median diameter and percentage of fineparticles less than 3µm ( color toner with polyester resin)

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Relation between the median diameterand specific energy consumption( color toner with polyester resin)

ＮNISSHIN SEIFUN(3)(1) Screw feeder (4) Cyclone(2) Super Jet Mill (5) Bag house(3) New classifier (6) Blower

(1)

(5)

(4)

(3)

(2)

Fine particles

Product(Coarse particles)

A new classifier forfine classification

Super Jet Mill system with a new classifier
without rotor for color toners

15

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Pulverized toner using SJ system
Median diameter : 7.7µm
Less than 4µm : 26 pop%
Product yield : 93%

20µm

Conventional pulverized tonerMedian diameter: 7.0µm
Less than 4µm : 53 pop%

Comparison of two kinds ofpulverized toners

Ｎ20µm

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20µm

20µm

20µmMedian diameter : 7.5 µm
Less than 4µm : 12 pop%
Circularity Index : 0.99

Median diameter : 6.2 µm
Less than 4µm : 11 pop%
Circularity Index : 0.97

Median diameter : 5.6 µm
Less than 4µm : 24 pop%
Circularity Index : 0.97

Canon

Ricoh

Fuji Xerox( Suspension)( Ester elongation )(Emulsion aggregation )Example of chemical toners on the market

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Pulverized tonerMedian diameter : 5.4 µm
Less than 4µm : 26 pop%

Chemical tonerMedian diameter : 5.6 µm
Less than 4µm : 24 pop%Particle size distributions of pulverized tonerusing Super Jet Mill system and chemical toner

ＮNISSHIN SEIFUNMedian diameter : 5.4 µm
Less than 4µm : 26 pop%
Circularity Index : 0.96
Product yield: 80%

Median diameter : 5.6 µm
Less than 4µm : 24 pop%
Circularity Index : 0.9720µm

Chemical toner

20µm

Pulverized toner using
Super Jet mill system

Comparison of particle characteristics
of chemical toner and pulverized tonerusing Super Jet Mill system

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Conclusions
1) In order to save energy and running costs,
it is important to use a suitable grinding
machine for particle size and characteristics
of toners because it consumes a lot of energy
compared with other machines.
2) Using grinding and classifying technologies,
it is possible to produce toners similar tochemical ones in particle shape and size
distribution.

ＮNISSHIN SEIFUN

Thank you very muchfor your kind attention.

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