As the rod moves in the direction of the secondary extrudate 42 it contacts the primary extrudate 41 and thereafter causes {HEAD ~ the primary extrudate} to move toward {TAIL ~ the secondary extrudate} 
As the rod moves in the direction of the secondary extrudate 42 it contacts the primary extrudate 41 and thereafter causes { HEAD ~ the primary extrudate } to move toward { TAIL ~ the secondary extrudate }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL