Upon cooling, {TAIL ~ the first and second layers} will fuse thereby forming {HEAD ~ a matrix} through which the stiff core 12 are distributed 
Upon cooling , { TAIL ~ the first and second layers } will fuse thereby forming { HEAD ~ a matrix } through which the stiff core 12 are distributed
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH