Global Patent Index - EP 1065314 A1

EP 1065314 A1 20010103 - Process for making paper products

Title (en)

Process for making paper products

Title (de)

Verfahren zur Herstellung von Papierprodukten

Title (fr)

Procédé de fabrication de produits papetiers

Publication

EP 1065314 A1 20010103 (FR)

Application

EP 00401639 A 20000609

Priority

FR 9908482 A 19990701

Abstract (en)

During the prodn. stages for a paper material, using a fraction of recycled paper pulp, the acidification stage uses an injection of carbon dioxide into the pulp suspension at a point where the fractions are in the process circuit between the outlet of the pulper (15) for the used paper fraction and the mixing point where the pulp is mixed with fresh pulp. The second stage dilutes the pulp in at least two phases, using clean water which has been injected with carbon dioxide. The clean water is recovered from the papermaking machine or from an external supply such as from the pulp preparation stage and/or cleaned water recovered from other stages. The carbon dioxide is injected pref. at two points in the fraction treatment circuit, on leaving the pulper for the fractions and the end point of the treatment process. The second fraction processing stage has at least one phase where lumps are broken down and/or at least one complementary cleaning phase for the pulp delivered by the pulper (15). The first injection of carbon dioxide is to set the pH at an intermediate level for the grinding and/or cleaning phases. The second injection gives the diluted pulp a pH compatible with the pH level in force during the mixing stage (2). The diluted pulp has a pH value of 5.5-8.5 from the fraction treatment, and the intermediate pH value of the pulp during grinding and/or cleaning is 7.5-9.0 and pref. 8.0-8.5. The carbon dioxide is injected into one and/or more of the points of: Into the clean water used to dilute the fractions (18); into the clean water (20) for dilution at the outlet of the fraction pulper (15); into the clean water for final dilution of the fraction mixed with fresh pulp; into the pulp fraction on leaving the pulper (15) and before the following stages; or into the pulp fraction at the end of the processing but before mixing with fresh pulp. The carbon dioxide is fed by an initial dilution water feed on leaving the pulper to give a pH value of 7.5-9.0 and pref. 8.0-8.5 to the level at the grinder, and by a second dilution water feed between the grinder and the final stage to give a pH value for the diluted pulp equal to the level in force at the pulp mixing stage, where the fraction is mixed with the remainder of the cellulose pulp. The carbon dioxide is fed as a gas or a liquid, or partially a gas and partially a liquid.

Abstract (fr)

L'invention concerne un procédé de fabrication d'un produit papetier à partir de pâte cellulosique dont une partie provient de cassés, lesdits cassés ayant subi un traitement dit traitement des cassés comprenant : une première étape consistant en une remise en solution sous agitation et en milieu alcalin des fibres cellulosiques contenues dans lesdits cassés, ladite étape étant réalisée dans un pulpeur dit pulpeur à cassés (15). puis une deuxième étape, destinée à amener la pâte issue dudit pulpeur (15) à une concentration et à un pH voisin de ceux de la pâte neuve contenue dans le cuvier de mélange (2), ladite deuxième étape comprenant au moins une étape de dilution par des eaux blanches du procédé et au moins une étape d'acidification réalisée par injection de CO2 gazeux ou liquide en au moins un point du circuit de traitement des cassés situé entre la sortie du pulpeur à cassés (15) et le mélange de la pâte issue du traitement des cassés avec la pâte neuve. Le procédé est avantageusement mis en oeuvre en introduisant le CO2 dans les eaux blanches servant à diluer la pâte issue du traitement en milieu basique des cassés. <IMAGE>

IPC 1-7

D21H 17/65; D21H 23/14; D21H 11/14

IPC 8 full level

D21H 11/14 (2006.01); D21H 17/65 (2006.01); D21H 23/14 (2006.01)

CPC (source: EP)

D21H 11/14 (2013.01); D21H 17/65 (2013.01); D21H 23/14 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

DOCDB simple family (publication)

EP 1065314 A1 20010103; EP 1065314 B1 20070606; AT E364107 T1 20070615; BR 0002954 A 20010403; CA 2311279 A1 20010101; DE 60035084 D1 20070719; DE 60035084 T2 20080131; ES 2286991 T3 20071216; FR 2795753 A1 20010105; FR 2795753 B1 20010914; PT 1065314 E 20070806

DOCDB simple family (application)

EP 00401639 A 20000609; AT 00401639 T 20000609; BR 0002954 A 20000630; CA 2311279 A 20000609; DE 60035084 T 20000609; ES 00401639 T 20000609; FR 9908482 A 19990701; PT 00401639 T 20000609