A method 1 or 2, including {HEAD ~ blending} of the material with {TAIL ~ a foaming agent} which will chemically decompose during the extruding 
with
A method 1 or 2 , including { HEAD ~ blending } of the material with { TAIL ~ a foaming agent } which will chemically decompose during the extruding
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH