providing a first roller adapted to receive {HEAD ~ the additive material} within {TAIL ~ a plurality} of spaced apart pockets located on its roll face 
within
providing a first roller adapted to receive { HEAD ~ the additive material } within { TAIL ~ a plurality } of spaced apart pockets located on its roll face
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH