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Andritz Inc
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Individual
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Priority claimed from GB919111256Aexternal-prioritypatent/GB9111256D0/en
Application filed by IndividualfiledCriticalIndividual
Publication of CA2069281A1publicationCriticalpatent/CA2069281A1/en
Application grantedgrantedCritical
Publication of CA2069281CpublicationCriticalpatent/CA2069281C/en
Paper pulp (e.g. kraft pulp or sulfite pulp) is produced utilizing at least two different supplies of cooking liquor (e. g. white liquor), having different percentages of lignin reaction enhancing or carbohydrate degradation slowing chemicals (e.g. one having low sulfide content, and the other high sulfide content). The high sulfide content supply is typically used to impregnate the pulp, while the second supply is used in other cooking stages (whether co-current or countercurrent). At least 60% of the sulfide of the cooking chemicals may be prodded in the first supply. Some of the sulfide in the first supply is desirably provided in the form of polysulfide or elemental sulfur. When about 2% polysulfide on wood is utilized yield is significantly increased. Utilizing multiple chemical (e. g. sulfide) content supplies results in an optimum viscosity/kappa ratio and/or pulp strength properties for the pulp produced.
CA 20692811991-05-241992-05-22Multi-level sulfide content pulping
Expired - Fee RelatedCA2069281C
(en)
Process to inhibit the reversal of brightness on a substrate containing lignin; process to reduce the reversal of the brightness of bleached pulps containing lignin; process to reduce the reversal of the brightness of pulps containing lignin for use as newsprint; lignocellulosic article resistant to reversal of gloss; paper; pulp; bleached thermomechanical pulp; bleached chemothermomechanical pulp sheet of paper comprising bleached pulps containing lignin; sheet of paper comprising