Design expert plot: impact of time at peak temperature
and temperature on quality of calcined powder
FIGURE 1: Visualisation of results from FED analysis.
Actual factors:
0.00 1.00 6.0 4. 5 1.5 1475 1525 1550
Desirability
0.75
0.50
0.25
1500
Temperature
3.0
Time
0.0 1450
Silicone & Thermoplastic Manufacturing Services for Your Medical Device
■ the temperature-time profile experienced
by the powder mix on heating
■ type or level of milling performed on
end powder
■ storage conditions, such as humidity,
which affect powder quality over time.
Using trial and error to alter variables
and thereby optimise product quality can be
time consuming and expensive for medical
device manufacturers. Factorial experimental
design (FED) modelling studies can help
to eliminate this trial and error. By listing
variables and defining the end properties
that are desired, modelling software will
suggest a reduced number of experiments.
Those experiments will feature different combinations of variables, which are
assigned a high, low and perhaps intermediate value. Once the experiments have been
performed, the results can be depicted in a
suite of three-dimensional (3D) graphs that
illustrate the combined impact of any two
variables. The graph in Figure 1 shows the
effect of heating time and the maximum
When you partner with Vesta, you receive quality and value at every stage of your product’s
lifecycle. And, you’ll never have to slow your pace of innovation or compromise your
manufacturing standards. For nearly 40 years, manufacturers have depended on Vesta for:
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Vesta is the proud recipient of a 2009 Frost & Sullivan category leadership award.
Visit us at www.vestainc.com/trust.
Trust us. Top manufacturers around the world already do.
emdt.co.uk European Medical Device Technology
June 2010 | 19
