Search

The bonding potential of pulp fibers is reduced by the paper recycling process. The most common technique for recovering this lost potential of secondary fibers involves upgrading the recycled pulp by blending it with virgin softwood pulps. In this research, we asses print stability on acid agents of UV inkjet prints when using straw pulp as reinforcing fibers in recycled papers. For that purpose, printing substrates were formed on the Rapid Köthen device from pulp obtained by blending different proportions of straw pulp and pulp of recycled fibers. Each printing substrate was printed in full tone with cyan, magenta, yellow, and black inks by digital technique of UV inkjet printing. Printed substrates were treated with various inorganic and organic acids under the conditions defined in the international standard ISO 2836:2004. Based on the measured spectrophotometric values of the untreated and acid-treated prints, the Euclidean color difference (ΔE00*) was defined and the stability of prints was assessed. The results of spectrophotometric measurements indicate small to medium color differences of the prints due to the effect of all acids (ΔE00max. * < 2.4) and it can be concluded that straw pulp in printing substrates from recycled fibers contributes to good chemical stability of prints. This research concludes that straw, as an annual renewable resource, can be used in conjunction with waste paper as an alternative to wood, which is currently the dominant raw material for graphic industry and producing paper. [ABSTRACT FROM AUTHOR]

Abstract: A methodology for capillary electrophoresis/electrospray ionisation mass spectrometry (CE/ESI-MS) was developed for the simultaneous analysis of degradation products from paper among two families of compounds: low molar mass aliphatic organic acids, and aromatic (phenolic and furanic) compounds. The work comprises the optimisation of the CE separation and the ESI-MS parameters for improved sensitivity with model compounds using two successive designs of experiments. The method was applied to the analysis of lignocellulosic paper at different stages of accelerated hygrothermal ageing. The compounds of interest were identified. Most of them could be quantified and several additional analytes were separated. [Copyright &y& Elsevier]

In this study, capillary electrophoresis (CE) was used for separation of inorganic and organic ions from waters of paper and paperboard machines at mills. The instrument was constructed for on-line measurements by building a batch-type sample feeding unit. Chloride, thiosulphate, sulphate, oxalate, sulphite, hydrogen sulphide, formate, carbonate, phosphate and acetate in the process water samples were separated using an ion-specific separation system in CE with dicarboxylic acid buffer (pH 8.2), with pyridinium-2,3-dicarboxylic acid modified with commercial NICE-Pak OFM&z.sbnd;OH solution (pH 12.0) or with a cetyltrimethylammonium bromide solution modified with chromate (pH 10.6). In addition, Analis CEofix Anions 8 electrolyte solution was tested in on-line studies at mills. It allowed 5 min separation time for the anions. Aluminium was determined at pH 3.6 in 10 min by using a laboratory-made imidazole buffer modified with 18-crown 6-ether. The developed CE systems were used to monitor the concentrations of sulphur species in dithionite degradation, to estimate corrosion degree in the water tanks, to monitor formaldehyde as the biocide chemical in wire washing and, in general, to observe process disturbances resulting from chemical feedings and their sites. The CE combination was on-line coupled to eight different process machines for continuous monitoring of concentrations for periods between two weeks and one month at paper and pulp mills in Finland. [Copyright &y& Elsevier]