Especially good, after merging, relative hardening of {TAIL ~ the second region} by {HEAD ~ the irradiation} can be achieved if from about 5 to about 70 weight percent of at least one substance that can be crosslinked or polymerized by ionizing radiation is uniformly incorporated into the PVC material for the second region and the irradiation provides such ionizing radiation 
Especially good , after merging , relative hardening of { TAIL ~ the second region } by { HEAD ~ the irradiation } can be achieved if from about 5 to about 70 weight percent of at least one substance that can be crosslinked or polymerized by ionizing radiation is uniformly incorporated into the PVC material for the second region and the irradiation provides such ionizing radiation
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH