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Journal articles
Bleaching of nonwood pulps: can sodium hydroxide be replaced with sodium carbonate in the alkaline extraction of nonwood pulps?, TAPPI JOURNAL, August 1991, Vol. 74(8)
Bleaching of nonwood pulps: can sodium hydroxide be replaced with sodium carbonate in the alkaline extraction of nonwood pulps?, TAPPI JOURNAL, August 1991, Vol. 74(8)
Journal articles
On-machine maintenance, TAPPI JOURNAL, August 1991, Vol. 74(8)
On-machine maintenance, TAPPI JOURNAL, August 1991, Vol. 74(8)
Journal articles
New trends in deinking technology removing difficult inks from wastepaper, TAPPI JOURNAL, February 1991, Vol. 74(2)
New trends in deinking technology removing difficult inks from wastepaper, TAPPI JOURNAL, February 1991, Vol. 74(2)
Journal articles
Color removal from kraft bleach-plant effluents by trichoderma sp., TAPPI JOURNAL, January 1991, Vol. 74(1)
Color removal from kraft bleach-plant effluents by trichoderma sp., TAPPI JOURNAL, January 1991, Vol. 74(1)
Journal articles
Bleaching deinked pulps, TAPPI JOURNAL, January 1991, Vol. 74(1)
Bleaching deinked pulps, TAPPI JOURNAL, January 1991, Vol. 74(1)
Journal articles
Characterization of refined papermaking pulps using hydrodynamic parameters from filtration analysis, TAPPI JOURNAL May 2015
Characterization of refined papermaking pulps using hydrodynamic parameters from filtration analysis, TAPPI JOURNAL May 2015
Journal articles
Magazine articles
Evaluation of soap recovery efficiency from black liquor — analytical tools, TAPPI Journal April 2023
ABSTRACT: Soap skimmings (“soap”) are typically recovered from black liquor in kraft mills that process a high percentage of softwood. In many mills, the recovery of soap is inefficient, negatively impacting performance of evaporators and recovery boilers and resulting in loss of potential revenue. A thorough evaluation of soap recovery performance in a kraft mill requires measurement of soap content in black liquor at various sampling locations, especially around the soap skimmer.The standard laboratory method for evaluating soap content in black liquor is a complex, multi-step process that relies on solvent extraction and titration; most mills send these samples to an outside laboratory for this analysis. In this study, 100 black liquor samples, with a wide range of soap concentrations, were tested by the standard solvent extraction method. After additional dilution, each sample was also tested for surface tension with a bubble pressure tensiometer. The results were found to correlate very closely with the solvent extraction tests results. This alternate method, using surface tension measurements of diluted black liquor samples, produces rapid results and can be easily implemented in most kraft mills, which would facilitate much more frequent in-house evaluations of soap recovery performance.
Journal articles
Magazine articles
Application of ATR-IR measurements to predict the deinking efficiency of UV-cured inks, TAPPI Journal January 2022
ABSTRACT: In recent years, ultraviolet (UV)-curable ink has been developed and widely used in various printing applications. However, using UV-printed products (UV prints) in recovered paper recycling causes end-product dirt specks and quality issues. A new method was developed that can distinguish UV prints from other prints by means of attenuated total reflectance infrared (ATR-IR) spectroscopy. Application of this method could allow more efficient use of UV prints as raw materials for paper recycling.First, a mill trial was performed using UV prints alone as raw materials in a deinked pulp (DIP) process. Second, test prints were made with four types of UV inks: a conventional UV ink and three different highly-sensitive UV inks. Each print sample had four levels of four-color ink coverage patterns (100%, 75%, 50%, and 25%). Next, deinkability of all prints was evaluated by laboratory experiments. Finally, each print was measured using the ATR-IR method, and the relationship between the IR spectra and deinkability was investigated. Mill trial results showed that UV prints caused more than 20 times as many dirt specks as those printed with conventional oil-based ink. There were variations in recycling performance among UV prints taken from bales used for the mill trial. Lab tests clearly revealed that not all UV-printed products lead to dirt specks. In order to clarify the factors that affected deinkability of UV prints, the print samples were investigated by lab experiments. Key findings from lab experiments include: œ The number of dirt specks larger than 250 µm in diameter increased as the ink coverage increased. œ Higher ink coverage area showed stronger intensity of ATR-IR spectral bands associated with inks. These results indicate that deinkability of UV prints could be predicted by analysis of ATR-IR spectra. œ Finally, the method was applied for assessment of recovered paper from commercial printing presses. It was confirmed that this method made it possible to distinguish easily deinkable UV prints from other UV prints. Based on these findings, we concluded that the ATR-IR method is applicable for inspection of incoming recovered paper.
Journal articles
Separation of fiber and ash in deinking effluents: a case study, TAPPI JOURNAL, May 1995, Vol. 78(5)
Separation of fiber and ash in deinking effluents: a case study, TAPPI JOURNAL, May 1995, Vol. 78(5)
Journal articles
Comparing papermaking wet-end charge-measuring techniques in kraft and groundwood systems, TAPPI JOURNAL, November 1995, Vol. 78(11)
Comparing papermaking wet-end charge-measuring techniques in kraft and groundwood systems, TAPPI JOURNAL, November 1995, Vol. 78(11)