LCR7000 & RHEOSIGHTS P/N: 974194 |
Rev: A
|
ECO: 52468
www.dynisco.com
From lab to production,
providing a window into the process
-90-
4
2
10
24
x
=
σ
Pa
In some cases, a higher temperature (250
o
C) is used. An experimentally
determined conversion factor (2.30) is used to convert the shear rate at
250
o
C to that at 190
°
C.
(
)
(
)
30
.
2
/
250
,
10
2
190
,
10
2
4
1
4
1
C
x
C
x
γ
γ
=
(
)
(
)
30
.
2
/
250
,
10
24
190
,
10
24
4
2
4
2
C
x
C
x
γ
γ
=
Additionally, a low stress
σ
3
is sometimes used, along with the higher
temperature, to avoid melt fracture. In this case another correction is made
to convert back to the
σ
2
level. (Note the 1.83 applies only to the higher stress
level.)
4
3
10
20
x
=
σ
Pa
(
)
(
)
30
.
2
/
83
.
1
250
,
10
20
190
,
10
24
4
2
4
2
C
x
C
x
γ
γ
=
(
)
(
)
NNI
C
x
C
x
=
190
,
10
4
190
,
10
24
4
1
4
2
γ
γ
A unitless value.
4
1
10
4
x
=
σ
Pa
