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