Products are monitored and controlled through the manufacturing process
using real time statistical tracking software. Rigorous quality control
standards are maintained from mixing our raw materials to producing finished
ferrite powder and compound. Production and maintenance personnel, quality
technicians, clerical staff and plant management personnel are dedicated
problem solvers and are well trained in understanding the manufacturing
process and the expectations of our customers. We are proud that Hoosier
Magnetics is ISO 9001 certified.
Specific Gravity = 1.02
Compounding of the LEEP Ferrite – Binder Mix:
Our mixing equipment consists if a 6 X 12 inch two-roll rubber mill
operating at 25 RPM with a friction ratio of 1:1:1. The rolls are heated
to a temperature of 99 C and the gap between the roll is adjusted to 0.20
mm. 100 grams of binder is added to the mill first, then 900 grams of
ferrite powder is introduced to the mill and mixed by standard techniques.
The flexible sheet is finally brought to a thickness of 4.0 mm for magnetic
testing by opening the rolls, laminating, and calendaring.
HEEP QUALITY CHECK PROCEDURE
Each lot of HEEP powder is quality checked using the following procedure:
Preparation of Binder (Composition B):
|
Weight in Grams
|
Material
|
Manufacturer
|
Grade
|
|
680
|
Chlorosufonated Polyethylene
|
Dupont
|
Hypalon 45
|
|
320
|
Polyisobutylene
|
EXXON
|
Vistanex 140
|
|
54
|
Pentaerythritol Ester of Resin
|
Hercules
|
Pentalyn G
|
|
22
|
Lubricant
|
Acme Hardesty
|
Stearic Acid 60R
|
Specific Gravity = 1.02
Compounding of the HEEP Ferrite:
Compounding Equipment
Our mixing equipment consists if a 6 X 12 inch two-roll rubber mill
operating at 25 RPM with a friction ratio of 1:1:1 is used to prepare
the ferrite plastic mixes and calendared sheets.
Compounding of 89.0% HEEP using above binder
The rolls are heated to a temperature of 95 C and the gap between
the roll is adjusted to produce a 2.7 mm sheet. 200 grams of binder is
sheeted to the mill, and 1618 grams of HEEP ferrite powder is introduced
to the mill and mixed by standard techniques. The flexible sheet is evaluated
to determine magnetic properties and specific gravity.
CERAMIC QUALITY CHECK
PROCEDURE
Each lot of ceramic powder is quality checked using the following procedure:
MILLING
- 1.3 L steel jar mill
- 3.0 KG of 0.317 diameter steel balls
- 200 grams of ceramic ferrite powder
- Wet mill additives
- 325 ml of water
- 90 RPM mill speed
Allow mill to run for 10n hours to achieve a particle size of 0.7 microns
(+ 0.05 microns) as measured using a Fisher Sub-Sieve Sizer, using
a 5.15 gram sample.
PRESSING
Concentrate slurry to 70(+5) weight percent solids.
- Orienting field----------------------9000 Oersted
- Final Pressing Tonnage--------986 KPa
- Wet Green Density----------------3.20-3.25g/cm3
SINTERING
Sinter to obtain a fired density of 4.95 (+0.05) g/cm3.
Typical cycle of approximately ten hours with a peak temperature of 1240
°C (+5°C) as determined by Reidhammer rings.
LOI 15-16%