Lecourt M.,Institut Universitaire de France |
Sigoillot J.-C.,French National Institute for Agricultural Research |
Petit-Conil M.,Institut Universitaire de France |
Petit-Conil M.,Domaine University 251
Process Biochemistry | Year: 2010
Paper production requires fibres to be refined, meaning mechanically treated to present sufficient bonding potential. As it is a highly energy consuming stage, various charges of cellulase as a pre-treatment were investigated to reduce the energy consumption and improve paper properties. The enzyme was added during pulp slushing and conditions of treatment were chosen to be compatible with an industrial application. Results obtained after low consistency disc refining of a softwood bleached kraft pulp were compared at a given drainage index. Enzymatically-treated samples showed a better development of fibrillation leading to a stronger paper. Moreover, fibre swelling was significantly improved. The impact of cellulase charge added to the pulp was identified. However, for all cellulase charges tested, fibre intrinsic resistance was lowered. Consequently fibres became shorter and tear index dropped. A solution was found by applying a milder treatment consisting in reducing refining intensity. This was a way to limit the intense fibre cutting at high refining levels. Moreover, by treating pulp with cellulase, it became possible to reduce refining intensity by 33%, keeping breaking length similar to control. © 2010 Elsevier Ltd.
Bordenave N.,CNRS Organic Polymer Chemistry Laboratory |
Bordenave N.,PepsiCo |
Kemmer D.,Fraunhofer Institute for Process Engineering and Packaging |
Smolic S.,Fraunhofer Institute for Process Engineering and Packaging |
And 3 more authors.
Journal of Renewable Materials | Year: 2014
Aroma and oxygen-barrier properties of chitosan-coated papers were measured in order to evaluate the potential of these materials as biodegradable materials for food packaging. Firstly, two chitosans (Chi- 244 and Chi-652) were studied according to their ultimate biodegradability. Chi-652 showed the best final biodegradation rate and was then used for subsequent tests in association with papers. Then, oxygen-barrier and aroma-barrier properties of papers, Chi-652 films and Chi-652-coated papers were investigated. The Chi-652 films exhibited oxygen-barrier at low relative humidity and aroma-barrier comparable to synthetic materials already used in the packaged food industry. Both papers exhibited poor barrier properties toward oxygen and aromas. Although chitosan-coated papers showed promising results in regard to the aromabarrier performance of papers, it did not improve their oxygen-barrier properties, probably because of the impact of the coating process on the tri-dimensional structure of the papers. © 2014 Scrivener Publishing LLC.
Bigand V.,CNRS Research on Catalysis and Environment in Lyon |
Bigand V.,Domaine University 251 |
Pinel C.,CNRS Research on Catalysis and Environment in Lyon |
Perez D.D.S.,Domaine University 251 |
And 3 more authors.
BioResources | Year: 2013
Cationizations of galactomannan- and xylan-type hemicelluloses were performed in a solid state, with 2,3-epoxypropyltrimethylammonium chloride (ETA) as the cationic reagent under alkaline conditions. By this method, the reaction efficiency was significantly increased for all hemicellulose types, up to 90% in the case of xylan. The consumption of reagents was reduced by a factor of ten when compared to the reaction in liquid phase, while comparable values of the degree of substitution (DS) were obtained. By reducing the number of purification steps, the consumption of solvents was limited, and high mass yields were preserved. By all aspects, this method constitutes an economical and environmental gain for the cationization reaction of hemicelluloses. Native hemicelluloses and their cationic derivatives were tested as additives to the pulp slurry in order to increase the dry strength of the paper formed. The cationization of hemicelluloses had a beneficial effect on the mechanical properties of paper, with a supplementary gain of properties compared to the unmodified polysaccharides. Cationic derivatives of a DS 0.3 gave the best results for both polysaccharides, with the galactomannan-type being more efficient than the xylan-type with a 90% increase of the burst index.
Bertaud F.,Domaine University 251 |
Tapin-Lingua S.,Domaine University 251 |
Pizzi A.,University of Lorraine |
Navarrete P.,University of Lorraine |
Petit-Conil M.,Domaine University 251
ATIP. Association Technique de L'Industrie Papetiere | Year: 2011
In order to reduce formaldehyde emissions from wood panels, and to develop green adhesives, natural phenolic polymers of tannins and lignin have been investigated as substitutes of petrol-based chemicals used in wood panels. The potential of several industrial wood barks wastes from pulp mills has been evaluated for tannin extraction, and further for their adhesive properties Aqueous extractions were carried on five industrial wood barks at the laboratory scale. Aleppo pine barks led to the highest yield (15%) compared to spruce, douglas fir, maritime pine and eucalyptus. Urea and sulfite used as wateradditives favoured condensed tannins extraction especially for spruce and douglas fir barks. Eucalyptus barks presented the lowest tannins contents. Pyr-GC/MS of bark extracts showed some wood specificity in term of phenolic structures, with mainly phenol and catechol type tannins in douglas fir and Aleppo pine bark extracts. Cooking liquors from pulp mill are very rich in lignin. Lignin was isolated by acidification/precipitation of black liquors. The characteristics of lignin obtained from softwoods and hardwoods kraft pulping, as from organosolv cooking of wheat straws and from bleaching/ extraction effluent of bisulphite pulp were compared. Precipitation procedures were optimised, and kraft lignins precipitated by acidification process shown a good purity and quality as well as orgonasolv lignin. These lignins after glyoxalation, presented interesting adhesive properties. Furthermore, novel formulations of [tannin/hexamine + glyoxalated lignin] were tested for wood particleboards manufacturing. The internal bond (IB) strength of a panel is a direct measure of the performance of the adhesive. Panels produced with 60% tannin/40% lignin mixture (and 50/50) as adhesive presented an IB strength satisfying the value required by the European standard.