Paper evenness is one of the most basic and important technical requirements in paper quality. Most of the paper quality indicators and performance are directly or indirectly related to paper evenness. The method or measure used to ensure the evenness of paper has a significant impact on the technical and economic effects of paper production.

With the continuous development of the papermaking machine, various types (horizontal, vertical, and arc) of paper-clamping machines have emerged, whose structural mechanism has been inspired and extended from the action mechanism of the finishing roller to varying degrees, and obtained significant effects.

In all kinds of long net paper making machines (except cigarette machine) in our country, the finishing roller is not listed as necessary equipment for matching, and it is arranged by the paper mill itself, so that the finishing roller is not widely used in most paper making machines. In order to achieve and maintain the necessary evenness of the paper, these long net papermaking machines, which are not equipped with the finishing roller, generally adopt high pulping degree, short fiber length (wet weight) and low Internet pulp concentration. As a result, the production efficiency of pulping and papermaking equipment decreases, some quality indicators of paper are adversely affected, and energy consumption and loss increase.