{HEAD ~ The material web} is guided through {TAIL ~ a gap} between the sonotrode and the counter tool and acted upon by the sonotrode 
is guided through
{ HEAD ~ The material web } is guided through { TAIL ~ a gap } between the sonotrode and the counter tool and acted upon by the sonotrode
HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH