{HEAD ~ A gap} is defined between the counter tool 14 and {TAIL ~ the sonotrode} 20 for passage of the material web 12 
is defined between
{ HEAD ~ A gap } is defined between the counter tool 14 and { TAIL ~ the sonotrode } 20 for passage of the material web 12
HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH