a counter tool placed in opposition to the sonotrode to define a gap there between for {HEAD ~ passage} of {TAIL ~ the material web} 
of
a counter tool placed in opposition to the sonotrode to define a gap there between for { HEAD ~ passage } of { TAIL ~ the material web }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL