[time-nuts] Thermal time constant

[Neville Michie]

I have been wondering about achieving the rated thermal resistance  
from plastic foam,
the problem being that radiant transmission may be very strong  
through the foam.
What happens if you interleave concentric sheets of foam plastic with  
aluminium foil? (taking care to keep the foil
on isothermal surfaces)
Will this stop the radiant transfer and leave only the thermal  
conduction of the plastic foam?
cheers, Neville Michie