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Grenoble, France

Pras O.,CNRS Structural Engineering | Pras O.,Center Technique du Papier | Beneventi D.,CNRS Structural Engineering | Chaussy D.,CNRS Structural Engineering | And 2 more authors.
Journal of Materials Science | Year: 2013

In this study, microfibrillated cellulose (MFC) and dendritic copper were used as binder and conductive phase for the elaboration of self-standing conductive films and coatings. A filtration technique was used to prepare MFC/Cu films from particle dispersions in water and ethanol. In aqueous slurries copper oxidized and an additional corona treatment or the use of zinc particles as sacrificial anode were necessary to obtain films with conductivities ranging from 70 to 2500 S m-1, respectively. In ethanol-based MFC/Cu slurries, copper was subjected to limited oxidation. However, the low packing density of conductive particles (below the percolation threshold) led to resistive films which, after densification by calendering, displayed extremely high conductivities, up to 70000 S m-1. Aqueous MFC/Cu slurries were successfully used for the deposition of conductive coatings on copy paper by Mayer rod coating and screen printing, which were subsequently treated by corona discharge and calendering. The obtained coatings displayed intermediate conductivity (i.e. 95 and 570 S m-1 for rod coating and screen printing, respectively), which can be further increased using zinc particles or ethanol-based formulations. © 2013 Springer Science+Business Media New York. Source


Meyer V.,Domaine University 90251 | Lecourt M.,Grenoble Institute of Technology | Petit-Conil M.,Domaine University 90251 | Petit-Conil M.,Grenoble Institute of Technology
International Mechanical Pulping Conference, IMPC 2014, part of PulPaper 2014 Conference | Year: 2014

An industrial spruce primary-refined TMP was refined at high and low consistency (HC - LC) to determine the interest of LC refining. The optimisation of the main parameters of LC refining enabled to demonstrate that important energy savings were reached at the detriment of the pulp quality. Thus, HC and LC refining strategies were combined to produce a TMP with a comparable quality but with lower refining energy. Combination of HC refining at 170 ml CSF and LC refining to reach the final freeness was a promising solution to decrease significantly the specific energy for producing TMP. Source


Prasse S.,Domaine University 90251 | Meyer V.,Domaine University 90251 | Cochaux A.,Domaine University 90251
International Mechanical Pulping Conference, IMPC 2014, part of PulPaper 2014 Conference | Year: 2014

Although paper industry has already improved its environmental performances (paper recycling, biomass-energy consumption), some production stages continue to impact environment (heat consumption, fresh water use). Therefore, a method using the life cycle analysis approach was developed to assess the environmental footprint. The method was used to evaluate the environmental impact of the introduction of enzymes during refining. Finally it was shown that 18 % of energy consumption and 8 % of non-renewable energy consumption were saved. Source


Huber P.,Domaine University 90251 | Carre B.,Domaine University 90251 | Fabry B.,Domaine University 90251 | Kumar S.,Domaine University 90251
Nordic Pulp and Paper Research Journal | Year: 2013

Stratified forming for lightweight grades is a promising concept, which has the potential to improve the mechanical properties of the sheet. The inner and outer layers of the stratified sheet may consist of deinked pulps fractions mixtures, with various mechanical and optical properties. The objective of this study is to optimise the sheet structure by stratification to maximise bending stiffness properties. Four DIP fractions either rich in fibres or in fine elements were produced through a fractionation/deinking process. Their intrinsic physical properties were identified from mono-layer handsheets measurements. Then models for the stratified handsheet properties are proposed and validated against multi-layer handsheets measurements. Finally, optimised stratified sheet structure is investigated, while using the entirety of the available DIP fractions mass flows from the fractionation/deinking process. Source


Huber P.,Domaine University 90251 | Carre B.,Domaine University 90251 | Fabry B.,Domaine University 90251 | Kumar S.,Domaine University 90251
Nordic Pulp and Paper Research Journal | Year: 2013

With increasing utilisation rate of recycled raw material in newsprint and graphicpaper grades, dirt specks contamination is becoming critical. Predicting sheet contamination from pulp contamination level is not straigthforward, as only a fraction of the specks are actually visible in a thick sheet. We propose a specks extinction model to predict the visible contamination in sheets of paper made of deinked pulp. The modelling makes use of the optical properties of the sheet material, and the size distribution of the specks population. The model can be used for multi-layer sheets as well. We demonstrate that it is possible to minimise visible specks contamination through a combination of stratified forming and deinked pulp fractionation. Source

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