A statistical model of paper breaks in an integrated TMP-newsprint mill

Due to broke recirculation, the process of paper production is affected directly by the occurrence of breaks. In this paper a statistical model of paper machine breaks is developed. We start from the hypothesis that the breaks process is a Markov chain with three states: the first state is the operational one, while the two others are associated with the general types of paper breaks that can take place (wet breaks and dry breaks). The Markovian hypothesis is validated empirically. We also establish how paper break rates are correlated with machine speed and broke recirculation ratio. Subsequently, we show how the obtained Markov chain model of paper breaks can be used to optimize the choice of machine operating speed. The long-term goal is to use the statistical model to synthesize rational broke recirculation strategies.