Parameter Optimization for Biocompatible Polyamide Used …
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Here, σ m values represent the values obtained for tensile strength according to the
process parameters and av.σ m stance for its average value and standard deviation.
The values of SN ratio computed by maximization criterion are also presented.
The corresponding SN values for every factor and each level were then selected
and averaged. The computation result is denoted by Average S/N and is presented in
Table 4.
The relative difference (Rel.dif ) is computed by subtracting the lowest SN value
from the highest one (Table 4). The highest rank (I) is attributed to the highest relative
difference taken without sign. It signifies which of the control factors is generating
a higher influence on the goal parameters. As it can be observed, the energy density
plays the main role.
The optimal level for each factor was is also presented in Table 4. The highest
average SN ratio taken without sign for every factor represents the optimum value
for a high mechanical strength.
Table 4 Results of SN ratio and average analysis
Parameter
Level
Value
Average S/N
Rel. dif.
Rank
Optimal
E
0
0.073
29.884
9.638
I
E0
1
0.050
23.291
2
0.035
20.247
θ
0
0.0
23.679
1.605
II
θ1
1
30.0
25.285
2
45.0
24.459
T
0
169.5
24.556
0.568
III
T 2
1
170.0
24.149
2
170.5
24.717
Fig. 2 Representations of signal-to-noise ratio according to E, θ and T factors at three levels