By this construction, {TAIL ~ the edges} of the opening in the paperboard are sealed and cannot contaminate the liquid within {HEAD ~ a carton} formed from the blank 
By this construction , { TAIL ~ the edges } of the opening in the paperboard are sealed and can not contaminate the liquid within { HEAD ~ a carton } formed from the blank
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH