Documents disponibles écrits par cet auteur

Electroflotation combined with flotation deinking of flexographic newsprint / Akpojotor Shemi in Industrial & engineering chemistry research, Vol. 49 N° 5 (Mars 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 5 (Mars 2010) . - pp. 2380–2387 Titre : Electroflotation combined with flotation deinking of flexographic newsprint Type de document : texte imprimé Auteurs : Akpojotor Shemi, Auteur ; Jeffery S. Hsieh, Auteur Année de publication : 2010 Article en page(s) : pp. 2380–2387 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : flotation;  Flexographic;  Deinking;  Electrolytic Résumé : A semicontinuous flotation cell, which incorporates an electrolytic cell, was used to collect inks from newsprint pulp slurry. In general, longer pulping time has an adverse impact on deinking of 100% flexographic old newspaper or newsprint (flexo-ONP) while temperature has a positive impact on deinking. However, the use of electric field improved deinking efficiency—measured by the percent reduction in effective residual ink concentration (ERIC)—by as much as 5% at longer pulping time (25 min compared to 5 min). Higher temperature (40 °C compared to 25 °C) combined with the use of electric field further improved deinking efficiency by 5%. Furthermore, the impact of electric field assisted flotation is discussed in the context of the following variables: alkali charge (sodium hydroxide), float consistency (percent solids in the pulp suspension), surfactant and soap concentration, and the amount of flexo newsprint in a mixture of newspaper (or furnish)−newsprint. Unlike 100% flexo-ONP, the mixture of 48% flexo-ONP, 30% offset-ONP and 22% old magazine (OMG) contains both flexographic and offset inks, which have different ink sizes and chemistries. On average, considering all the variables, the use of electric field improved deinking efficiency by 3%. The best deinking efficiency was achieved at 1% consistency, when sodium hydroxide and surfactant and soap were added, combined with electric field. The deinking efficiency was corroborated with thermogravimetric analysis (TGA). Deinking efficiency is also discussed in terms of a deinking selectivity parameter called the Z-weighted factor. Note de contenu : Bibliogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012985 [article] Electroflotation combined with flotation deinking of flexographic newsprint [texte imprimé] / Akpojotor Shemi, Auteur ; Jeffery S. Hsieh, Auteur . - 2010 . - pp. 2380–2387. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 5 (Mars 2010) . - pp. 2380–2387 Mots-clés : flotation;  Flexographic;  Deinking;  Electrolytic Résumé : A semicontinuous flotation cell, which incorporates an electrolytic cell, was used to collect inks from newsprint pulp slurry. In general, longer pulping time has an adverse impact on deinking of 100% flexographic old newspaper or newsprint (flexo-ONP) while temperature has a positive impact on deinking. However, the use of electric field improved deinking efficiency—measured by the percent reduction in effective residual ink concentration (ERIC)—by as much as 5% at longer pulping time (25 min compared to 5 min). Higher temperature (40 °C compared to 25 °C) combined with the use of electric field further improved deinking efficiency by 5%. Furthermore, the impact of electric field assisted flotation is discussed in the context of the following variables: alkali charge (sodium hydroxide), float consistency (percent solids in the pulp suspension), surfactant and soap concentration, and the amount of flexo newsprint in a mixture of newspaper (or furnish)−newsprint. Unlike 100% flexo-ONP, the mixture of 48% flexo-ONP, 30% offset-ONP and 22% old magazine (OMG) contains both flexographic and offset inks, which have different ink sizes and chemistries. On average, considering all the variables, the use of electric field improved deinking efficiency by 3%. The best deinking efficiency was achieved at 1% consistency, when sodium hydroxide and surfactant and soap were added, combined with electric field. The deinking efficiency was corroborated with thermogravimetric analysis (TGA). Deinking efficiency is also discussed in terms of a deinking selectivity parameter called the Z-weighted factor. Note de contenu : Bibliogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9012985

Enzyme-assisted preparation of fibrillated cellulose fibers and Its effect on physical and mechanical properties of paper sheet composites / Sukjoon Yoo in Industrial & engineering chemistry research, Vol. 49 N° 5 (Mars 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 5 (Mars 2010) . - pp. 2161–2168 Titre : Enzyme-assisted preparation of fibrillated cellulose fibers and Its effect on physical and mechanical properties of paper sheet composites Type de document : texte imprimé Auteurs : Sukjoon Yoo, Auteur ; Jeffery S. Hsieh, Auteur Année de publication : 2010 Article en page(s) : pp. 2161–2168 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Cellulose  Fibers Résumé : The fabrication of fibrillated cellulose fibers and their utilization have been of more interest recently because of their biodegradability, low cost, and mechanical and thermal properties comparable to those of glass fibers or carbon fibers. In this study, we applied the combination of a mechanical shearing process with a cooling system and an enzymatic pretreatment to produce fibrillated cellulose fibers from softwood pulps. The effects of the mechanical shearing process, the cooling system, and the enzymatic treatment on the formation of the fibrillated cellulose fibers as well as physical and mechanical properties of paper were investigated. It was indicated that the cooling system was necessary in the grinding process to prevent the adverse effect of heat generation on mechanical properties of paper sheets. It was observed that the enzyme-assisted mechanical shearing process improves the production of fibrillated cellulose fibers and results in a substantial improvement of tensile strength and elongation of paper while producing thinner and less bright paper with low water absorptiveness. Note de contenu : Bibliogr ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901621n [article] Enzyme-assisted preparation of fibrillated cellulose fibers and Its effect on physical and mechanical properties of paper sheet composites [texte imprimé] / Sukjoon Yoo, Auteur ; Jeffery S. Hsieh, Auteur . - 2010 . - pp. 2161–2168. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 5 (Mars 2010) . - pp. 2161–2168 Mots-clés : Cellulose  Fibers Résumé : The fabrication of fibrillated cellulose fibers and their utilization have been of more interest recently because of their biodegradability, low cost, and mechanical and thermal properties comparable to those of glass fibers or carbon fibers. In this study, we applied the combination of a mechanical shearing process with a cooling system and an enzymatic pretreatment to produce fibrillated cellulose fibers from softwood pulps. The effects of the mechanical shearing process, the cooling system, and the enzymatic treatment on the formation of the fibrillated cellulose fibers as well as physical and mechanical properties of paper were investigated. It was indicated that the cooling system was necessary in the grinding process to prevent the adverse effect of heat generation on mechanical properties of paper sheets. It was observed that the enzyme-assisted mechanical shearing process improves the production of fibrillated cellulose fibers and results in a substantial improvement of tensile strength and elongation of paper while producing thinner and less bright paper with low water absorptiveness. Note de contenu : Bibliogr ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901621n