Carbon free copy paper is a novel copy paper, which is characterized in that writing on the upper layer of the copy paper can also be copied without padding the copy layer coated with ink. It is mainly used for multi sheet forms, bills, continuous finance bills and general business finance bills. For the processing of carbon free copy paper, coater is generally used for coating operation.

　　For the receipt of carbon free copy paper, it can be divided into upper paper, medium paper and lower paper. The coater used for carbon free copy paper has a single structure and can only carry out the coating operation of roll paper once, which makes the coating processing operation of paper cumbersome. Moreover, the coater generally only carries out the coating operation of paper once, which may lead to uneven coating of paper and poor use effect.