Identificação de causa raiz e estudo de melhoria do problema no processo de depuração da máquina de papel KRAFT

Abstract

The study refers to the cover product, which presents problems in appearance, causing complaints and even returns by the company's customers. The quality of a paper strongly depends on how clean the pulp is. Strange materials such as bark and wood chips, knots, sand, metallic particles, and other impurities can not only compromise the quality of the paper produced, but also cause damage to the machine, in addition to equipment wear, drying problems and additional steam consumption. The main characteristic of the problem is the presence of dirt/rejects and fibers with unwanted dimensions in the paper formation stage, which is carried out in the paper machine sector (PM). The objective of the study is to propose the improvement of the OM debugging step. After verifying and classifying the impurities, a "shives" test was carried out at the entrance and exit of the pine and eucalyptus refiners, with the purpose of verifying whether the fibers that are still united during refining, and in the purifiers are breaking down, to verify the efficiency of the removal of unwanted materials and impurities. It was seen in the acceptance that the scrubbers in the current configuration are not being effective, as there are impurities of various sizes, not having a good selectivity. The model for the new layout of the purification system will improve the selectivity of fibers and impurities, allowing for a better appearance of the final product.