supplying the additive material to within the pockets on {TAIL ~ the roll face} of {HEAD ~ the first roller} 
supplying the additive material to within the pockets on { TAIL ~ the roll face } of { HEAD ~ the first roller }
OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD