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