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Journal articles
Magazine articles
Modeling and parameter optimization of the papermaking processes by using regression tree model and full factorial design, TAPPI Journal February 2021
ABSTRACT: One of the major challenges in the pulp and paper industry is taking advantage of the large amount of data generated through its processes in order to develop models for optimization purposes, mainly in the papermaking, where the current practice for solving optimization problems is the error-proofing method. First, the multiple linear regression technique is applied to find the variables that affect the output pressure controlling the gap of the paper sheet between the rod sizer and spooner sections, which is the main cause of paper breaks. As a measure to determine the predictive capacity of the adjusted model, the coefficient of determination (R2) and s values for the output pressure were considered, while the variance inflation factor was used to identify and eliminate the collinearity problem. Considering the same amount of data available by using machine learning, the regression tree was the best model based on the root mean square error (RSME) and R2. To find the optimal operating conditions using the regression tree model as source of output pressure measurement, a full factorial design was developed. Using an alpha level of 5%, findings show that linear regression and the regression tree model found only four independent variables as significant; thus, the regression tree model demonstrated a clear advantage over the linear regression model alone by improving operating conditions and demonstrating less variability in output pressure. Furthermore, in the present work, it was demonstrated that the adjusted models with good predictive capacity can be used to design noninvasive experiments and obtain.
Journal articles
Magazine articles
Understanding wet tear strength at varying moisture content in handsheets, TAPPI Journal January 2021
ABSTRACT: A laboratory study was conducted looking at the effects of moisture content on wet tear strength in handsheets. Three different wetting techniques were used to generate the wet tear (Elmendorf-type) data at varying moisture levels, from TAPPI standard conditions (dry) to over 60% moisture content (saturated). Unbleached hardwood and softwood fiber from full-scale kraft pulp production were used. The softwood fiber was refined using a Valley beater to reduce freeness. Handsheets were made with a blend of hardwood and softwood and with refined softwood, without the addition of wet-end chemistry. The resulting grams-force tear data obtained from the test was indexed with basis weight and plotted versus both moisture content and dryness. As moisture content levels in the handsheets increased, the wet tear strength also increased, reaching a critical maximum point. This marked a transition point on the graph where, beyond a critical moisture content level, the tear strength began to decline linearly as moisture increased. This pattern was repeated in handsheets made from a blend of hardwood and softwood and from 100% refined softwood.
Journal articles
Magazine articles
The effect of microfibrillated cellulose on the wet-web strength of paper, TAPPI Journal January 2021
ABSTRACT: The wet-web strength of paper immediately after the press section of a paper machine is a critical factor in determining machine runnability. However, it is difficult to determine at commercial scale, because the web has to be broken and production interrupted in order to obtain a sample for measurement. The use of microfibrillated cellulose (MFC) is believed to increase wet-web strength, as it has allowed filler level increases of 10% or more on many commercial paper machines. In this paper, we describe a laboratory method for estimating the effect of MFC on wet sheet strength after press-ing, as well as actual measurements of wet-web strength from a pilot paper machine trial. These experiments have demonstrated the positive effect of MFC. At solids contents in the range typically observed after pressing, sheets with MFC at fixed filler content are significantly stronger, but also wetter, than those without it. When the use of MFC is combined with a typical increase in filler content, the wet web remains slightly stronger, but also becomes drier than the reference condition. These results are compatible with the theory put forward by van de Ven that wet-web strength is mainly a result of friction between entangled fibers, and they also suggest that the presence of MFC increases this friction.
Liquid plasma polymerization process for improved deinkability of pigmented inkjet digital printed paper, 2012 TAPPI PEERS Conference
Liquid plasma polymerization process for improved deinkability of pigmented inkjet digital printed paper, 2012 TAPPI PEERS Conference
Conference papers
IN-LINE PCC TECHNOLOGY CLEANS UP CIRCULATION WATER FROM DISSOLVED MATERIALS, METALS AND BIO BASED MICROORGANISMS RESULTING TO CLEAN PROCESS AND HIGH RUNNABILITY, 18PaperCon
IN-LINE PCC TECHNOLOGY CLEANS UP CIRCULATION WATER FROM DISSOLVED MATERIALS, METALS AND BIO BASED MICROORGANISMS RESULTING TO CLEAN PROCESS AND HIGH RUNNABILITY, 18PaperCon
Journal articles
Does kraft hardwood and softwood pulp viscosity correlate to
Does kraft hardwood and softwood pulp viscosity correlate to paper properties?, October 2016 TAPPI JOURNAL
Measurement and correction of baggy edges on paper machines, 2011 PaperCon Conference
Measurement and correction of baggy edges on paper machines, 2011 PaperCon Conference
Beyond RCM, 2008 Engineering, Pulping and Environmental Conference
Beyond RCM, 2008 Engineering, Pulping and Environmental Conference
The Fate of Silver from Recycled Printed Electronic Circuits, 2008 Engineering, Pulping and Environmental Conference
The Fate of Silver from Recycled Printed Electronic Circuits, 2008 Engineering, Pulping and Environmental Conference
Mechanism and Kinetics Studies of Oxidative Ammonolysis of Technical Lignins, 2000 Pulping / Process & Product Quality Conference Proceedings
Mechanism and Kinetics Studies of Oxidative Ammonolysis of Technical Lignins, 2000 Pulping / Process & Product Quality Conference Proceedings