Next, as the web of paper advances through the coater, a thin even coat is applied to one side,31 after which the web continues through a large gas-fired convection dryer to dry the coating. If a C2S product is being made, the sheet continues looping is such a manner as to position the other side of the paper for coating in a second coater in all respects to the first. For C1S products, the web of paper is simply routed to bypass the second coater. Exiting the coater, the paper is rewound on large reels.
Once coated, CFS paper may be calendered with the amount of calendering used dependent on the requirements of the product being made. Gloss grades are calendered the most, satin grades are calendered some, and matte grades are not calendered at all. The calenders, which are stacked, alternating hard (steel) and soft (plastic) rollers are used to increase the density, smoothness, and gloss of the paper. The combination of coating formulation and calendering regimen control the finish of the final sheet of paper.32
After coating and calendering, the reels of CFS paper are hoisted by large, overhead cranes to a rewinder which unwinds each reel, slits the web to the appropriate widths, and rewinds the resulting narrow webs onto paperboard cores. Rolls are produced in a wide range of widths depending on the width of the presses for which the paper is intended.33 In the U.S. market, CFS paper is sold both in sheet form and roll form, because commercial printers use both sheet-fed and web-fed offset lithographic
If the CFS paper is to be sold in roll form, the rolls are delivered from the rewinder to the roll
finishing area where they are wrapped and labeled for transport.
If the CFS paper is to be sold in sheet form, production entails one additional step. CFS rolls from the rewinder are delivered to a sheeter, which converts the paper from rolls to sheets. A CFS roll is mounted on a roll stand at the upstream end of the sheeter. As the roll advances through the sheeter, rotary knives cut the roll at regular intervals perpendicular to the direction of travel, thereby creating sheets. Large (i.e., wide) sheeters may also slit the roll longitudinally in addition to the perpendicular cuts being made by the rotary knives. The output from a sheeter is automatically stacked and counted in ream quantities on pallets. It is estimated that approximately 25 to 30 percent of the U.S. CFS market is for sheet-fed presses.35 CFS paper intended for sale to commercial printers using web-fed presses is reportedly somewhat different than that intended for sheet-fed presses.
Rolls for the web offset market have higher moisture content and different coating formulations in order to withstand the heat-set web printing process typically used for high-speed, web-fed presses.36
***; *** response to the producers’ questionnaire, p. 7; and The Dictionary of Paper, 4th ed. s.v.v. “cast coating, “reverse roll coating.” 31
***. ***. ***. Conference transcript, p.13 (Cameron), and Staff trip report, November 17, 2006. Conference transcript, pp. 102 (Anderson) and 167 (Hunley).