applying a combination of high frequency ultrasound waves and {HEAD ~ pressure} to {TAIL ~ the said pieces} of fabric, so overlapped and folded, along the layers of overlap and fold 
applying a combination of high frequency ultrasound waves and { HEAD ~ pressure } to { TAIL ~ the said pieces } of fabric , so overlapped and folded , along the layers of overlap and fold
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH