Further, if one or {HEAD ~ both} of {TAIL ~ the barrier layers} includes a metal foil, induction heating can be employed to seal the barrier layers together 
of
Further , if one or { HEAD ~ both } of { TAIL ~ the barrier layers } includes a metal foil , induction heating can be employed to seal the barrier layers together
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH