Recently, papermaking industry has executed waste paper recycling actively from the situation of global environment maintenance and resources protection. With this situation, pitch trouble has been increasing by increasing of the wastepaper usage rate, neutralization of papermaking pH, reduction of papermaking machine using water, speedup of papermaking machine. Pitch trouble is one of important cause of paper machine run ability. To reduce pitch trouble, various pitch control agent has been

more »

... lying. And many pitch evaluation methods has been using. Each method has various features and is used depending on the situation and a purpose. We use evaluation method noting Deposit potential , and we are applying pitch control agents and fixing agents. In this article, we collect concerning the basic item of the pitch and pitch control. And we introduce the example of application of the pitch control agent.