Overview
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André LEMAÎTRE: Engineer from the École Française de Papeterie de Grenoble (EFPG) - Doctorate in Automatic Engineering - Coordinator of the Consulting and Expertise Department at the Centre Technique du Papier (CTP)
INTRODUCTION
The paper machine itself will be used, from a raw material (or pulp) prepared for this purpose (cf. ), to produce a continuous sheet of paper or cardboard, of a given width and corresponding to well-defined specifications (grammage, thickness, given physical and optical properties). Modern machines currently reach speeds of 1,800 m/min (newsprint), and even 2,200 m/min for special machines used for sanitary and household papers. Some machine manufacturers are looking to increase speeds up to 2,500 m/min, and several pilot paper machines are already running in excess of 2,000 m/min for light grades (newsprint). Machine widths can reach 10 m, but an increase in width is unlikely in the short term.
The paper machine consists of three main parts (figure 1 ):
the wet section, comprising the headbox and the production table. This is where the sheet is formed and drained, first by gravity and then by vacuum;
the press section, where the sheet is mechanically dewatered as much as possible;
drying, where the remaining water is thermally eliminated (evaporation).
On leaving the dryer, the sheet, at a moisture content of between 4 and 9% (by mass), is stored in reels using a rewinder. Before this final stage, which represents the end of the paper machine, the sheet can undergo a number of additional in-line treatments: coating, coating, smoothing, calendering, etc. All these operations generally add value to the paper. All these operations, which generally add value to the paper, can of course be carried out off-machine, on special installations: coaters, calenders, supercalenders.
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Paper processes
Wet end
Economic data
According to the annual Pulp and Paper International survey published in July 2002, world production in 2001 amounted to 179,374,000 tonnes of pulp and 318,147,000 tonnes of paper and board (tables 1 , 2 and 3 ).
Specific consumption
Paper manufacturing consumes thermal energy, particularly in the dryer, and electrical energy at all stages of the process.
Paper manufacturing also consumes water at the various stages of pulp preparation, additives and on the paper machine. Some of this water is recycled (see wet-end circuit), while the surplus is sent to the wastewater treatment plant. Finally, it generates waste (sludge,...
Bibliography
Articles and books for [J 6 900]
Standards
Numerous standards have been specially designed for the paper industry, both for the classification and quality assessment of pulp, paper and board, and for the definition of the finished product. In France, paper industry standards are either AFNOR (NF Q standards), ISO (from the ISO/TC 6 technical committee) or CEN (EN standards) (from the CEN/TC 172 technical committee).
Please refer to the current...
Organizations
COPACEL (Confédération française de l'industrie des papiers, cartons et celluloses), which includes the following organizations:
PROCELPAC (French association of manufacturers of cellulose-based packaging materials) ;
French grouping of printing and writing paper manufacturers;
Syndicat des fabricants de papiers...
Manufacturers. Suppliers
Given the diversity of materials and equipment used by pulp, paper and board mills, it is not possible to provide an exhaustive list of manufacturers and suppliers. For this reason, various directories have been specially published for the paper industry, bringing together all the players in the profession.
Europa Birkner. Directory of the European paper industry. Producers, Converters,...
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