Sawing statistical process control in jeronimo monteiro, espirito santos, Brazil Sawing statistical process control in Jeronimo Monteiro, Espirito Santos, Brazil

Abstract

This study was conducted at the Pandico sawmill, located in Jerónimo Monteiro, Espírito Santo, Brazil, and aimed to evaluate the quality logs and sawn timber from Eucalyptus camaldulensis and Toona ciliata M. Roem var. australis. Fifty logs of each species were selected to determine their main defects. The principal aspects defining the quality of the sawing process were determined through statistical process control. The Eucalyptus camaldulensis logs exhibited 3 defects per m² of surface area, a higher number than Toona ciliata logs, which had 1 defect per m². This difference is primarily related to a greater number of splits at the ends of the logs. In the sawn pieces of Eucalyptus camaldulensis, oversizing is observed in relation to the critical dimension of 2.9601 mm per piece. Considering the final dimension of the 20 mm pieces, the oversizing is even greater, reaching 4.1152 mm, which implies a considerable volume of wood loss. For the 40 mm thick Toona ciliata assortment, oversizing is also evident, as the critical and optimal dimensions are defined as 41.7877 mm and 45.3265 mm, respectively, which corroborates the oversizing in the process. The use of control charts is a suitable tool for making decisions aimed at improving the quality of the sawn timber.