A plug is used in {HEAD ~ the thermoforming process} to contact the sheet and position {TAIL ~ the sheet} within a die 
to position
A plug is used in { HEAD ~ the thermoforming process } to contact the sheet and position { TAIL ~ the sheet } within a die
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH