By means of {TAIL ~ an otherwise conventional ultrasonic pressing operation}, an annular seal zone between {HEAD ~ the two barrier layers} and around the pouring aperture is formed 
By means of { TAIL ~ an otherwise conventional ultrasonic pressing operation } , an annular seal zone between { HEAD ~ the two barrier layers } and around the pouring aperture is formed
OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH