LCR7000 & RHEOSIGHTS P/N: 974194 |
Rev: A
|
ECO: 52468
www.dynisco.com
From lab to production,
providing a window into the process
-54-
Formulas Used in Data Analysis
Apparent Shear Rate Calculation:
Formula for Shear Rate
(Time)
Distance)
(
8
ime)
Distance/T
(
4
4
3
2
3
2
3
2
c
b
c
b
c
p
b
D
D
R
R
R
S
R
=
=
=
γ
Typical Units are 1/sec or sec
-1
.
Where:
R
b
= radius of the barrel
R
c
= radius of the capillary (die)
S
P
= speed of the plunger
D
b
= diameter of the barrel
D
c
= diameter of the capillary (die)
Example: When the plunger moves at a rate of 20 mm/min (or 20/60 mm/sec), the Die
diameter is 1mm, and the Barrel diameter is 9.545 mm
then:
243
)
60
(
)
1
(
)
20
(
)
545
.
9
(
8
3
2
=
=
γ
1/sec.
Note all length units cancel out.
Apparent Shear Stress Calculation:
Formula for Shear Stress
c
b
c
p
c
b
c
p
L
D
D
F
L
R
R
F
2
2
2
π
π
τ
=
=
Typical Units are Pascals (Pa) or megaPascals (Mpa).
Where:
R
b
= radius of the barrel
R
c
= radius of the capillary (die)
D
B
= diameter of the barrel
D
c
= diameter of the capillary (die)
F
p
= the load on the plunger (Ram)
Example: For a Ram load of 800 Newtons, die of diameter 1.0 mm and length 20 mm.