Magnetic Fluid

SIGMA HI-CHEMICAL INC.

Attracted by magnets--- the fluid's unique properties have charmed many researchers in various fields. A number of applications have been proposed, and some of them such as rotating shaft seals, vibration damper, tilt sensor or angle sensor are materialized.
Magnetic Fluid is a composite which consists of well dispersed ferromagnetic ultra-fine particles and vehicle. It acts ferromagnetically as a whole. We have completed Magnetic Fluids based on a variety of fluids, and they have high reputation in the field of seal, especially very high vacuum seal using alkyl-naphthaline or perfluoro-polyether base Fluid, and also in other applications.

Our Magnetic Fluid is composed of base liquid, ferromagnetic particles and chemically adsorbed surfactant. The vigorous thermal-movement makes particles avoid settling, and the repulsion caused by surfactant prevent aggregation between particles. As a result, it is so stable that no separation between solid and liquid, nor agglomeration of particles is seen even under a strong magnetic field.
The base liquids of Magnetic Fluids we serve are water, hydrocarbons and perfluoro-polyethers. The ferromagnetic materials used are magnetite and Mn-Zn complex ferrite.

Applications

Rotating shaft seal:
Damper:
Loudspeaker:
Sensor:
Sink & float separation:
Magneto-optic devices:

Vacuum, gas, dust and mist seals
Use of viscosity increases in magnetic field
Use of damping effect and heat transfer
Combination of transformability and magnetic properties
Use of fluid's buoyancy changes in magnetic field
Fluids' big double refraction in magnetic field

STANDARD MAGNETIC FLUIDS

(SI are used here click here to see CGS table and graphs)

Fluid Type Base Magnetization
mT at 1.2
MA/m Viscosity at 20/50°C
mPa-sec Specific Gravity
at 20°C Vapor Pressure
Pa at 20°C Applications

M-300
Water 32 30/ 1.41
Sink & Float Separation

N-304
N-504 Iso-paraffin 33
55 10/
22/ 1.14
1.40
General Test

A-300
A-400
A-500 Alkylnaphthalene
34
40
50
280/60
370/80
600/130 1.26
1.34
1.44 <1*10^-7
<1*10^-7
<1*10^-7 Dust seal
Vacuum seal

P-306 Poly-alpha-
olefin 34 180/50 1.20
Seals, bearings, loudspeakers

F-310 Perfluoro-
polyether 30 5000/1000 2.19 <7*10^-8 Heat, solvent, oxidation and radiation resistant
Vacuum seal, bearings
The above are typical data, should not be considered specification.

MAGNETIC FLUIDS' PHYSICAL PROPERTIES

E-mail: info@sigma-hc.co.jp

Fluid Type	Base	Magnetization mT at 1.2 MA/m	Viscosity at 20/50°C mPa-sec	Specific Gravity at 20°C	Vapor Pressure Pa at 20°C	Applications
M-300	Water	32	30/	1.41		Sink & Float Separation
N-304 N-504	Iso-paraffin	33 55	10/ 22/	1.14 1.40		General Test
A-300 A-400 A-500	Alkylnaphthalene	34 40 50	280/60 370/80 600/130	1.26 1.34 1.44	<110^-7 <110^-7 <1*10^-7	Dust seal Vacuum seal
P-306	Poly-alpha- olefin	34	180/50	1.20		Seals, bearings, loudspeakers
F-310	Perfluoro- polyether	30	5000/1000	2.19	<7*10^-8	Heat, solvent, oxidation and radiation resistant Vacuum seal, bearings