Experimental Investigation on Thermal Degradation …
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Fig. 7 CO and CH 4 concentrations for different materials and assemblies
be validated by CH 4 concentration as it is observed earlier that CH 4 is produced at
the end of the laminate decomposition (cf. Figure 4).
In case of the second assembly (i.e. Paint + Laminate + Honeycomb (P.L.H)),
the primary HRR peak (see Fig. 6) corresponds to the decomposition of paint and
laminate as discussed above. Here, the 2nd consecutive HRR peak representing
decomposition of laminate is slightly lower compared to the P.L case. This is because
of loss of heat due to the additional honeycomb structure. Therefore, in the case of
second assembly, the rise in back surface temperature is not as rapid as observed
in P.L test case (cf. Figure 8). As it is seen earlier the decomposition of methylene
bridges occurs at 450–550 °C. This temperature is achieved in the later part of the
test in case of the second assembly compared to P.L test case due to which release
of methane is also delayed (Fig. 7). After the primary decomposition (primary peak)
the honeycomb structure decomposition starts (52 s), which can be confirmed by CO
emissions of P.L.H and the honeycomb (Fig. 7).
In the final test case, a complete composite (with a laminate sheet at the back of
P.L.H assembly) is tested inside the cone calorimeter. In this case of composite, after
Fig. 8 Heat release rate (HRR) and back surface temperature of different assemblies
563
Fig. 7 CO and CH 4 concentrations for different materials and assemblies
be validated by CH 4 concentration as it is observed earlier that CH 4 is produced at
the end of the laminate decomposition (cf. Figure 4).
In case of the second assembly (i.e. Paint + Laminate + Honeycomb (P.L.H)),
the primary HRR peak (see Fig. 6) corresponds to the decomposition of paint and
laminate as discussed above. Here, the 2nd consecutive HRR peak representing
decomposition of laminate is slightly lower compared to the P.L case. This is because
of loss of heat due to the additional honeycomb structure. Therefore, in the case of
second assembly, the rise in back surface temperature is not as rapid as observed
in P.L test case (cf. Figure 8). As it is seen earlier the decomposition of methylene
bridges occurs at 450–550 °C. This temperature is achieved in the later part of the
test in case of the second assembly compared to P.L test case due to which release
of methane is also delayed (Fig. 7). After the primary decomposition (primary peak)
the honeycomb structure decomposition starts (52 s), which can be confirmed by CO
emissions of P.L.H and the honeycomb (Fig. 7).
In the final test case, a complete composite (with a laminate sheet at the back of
P.L.H assembly) is tested inside the cone calorimeter. In this case of composite, after
Fig. 8 Heat release rate (HRR) and back surface temperature of different assemblies