The workpiece may be a single piece of material or {HEAD ~ a plurality} of pieces of material which are bonded together under {TAIL ~ the influence} of heat and pressure 
bonded together under
The workpiece may be a single piece of material or { HEAD ~ a plurality } of pieces of material which are bonded together under { TAIL ~ the influence } of heat and pressure
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH