Method for manufacturing filler-containing paper
First Claim
1. A method of manufacturing paper using a paper machine in which stock is fed to a headbox of said machine to form the paper, said method comprising the steps of:
- introducing filler and pulp containing a high proportion of pulp fines into a reaction vessel;
mixing said filler with said pulp containing a high proportion of pulp fines in said reaction vessel to form a resultant mixture;
admixing the resultant mixture with retention agent in said reaction vessel to form flocs which contain the filler and said pulp containing a high proportion of pulp fines (coflocculation);
subjecting the flocs to a size-controlling shearing process in said reaction vessel for breaking down large flocs and agglomerating small flocs to form flocs having a mean particle size in a range of 2 to 4 mm; and
feeding the flocs to the stock upstream of the headbox, wherein the size-controlling shearing process is effected in a shearing zone in the reaction vessel in which the floc suspension is imparted with a helical rotational motion in the flow direction thereby engendering a controllable shearing effect between adjacent layers at varying distances from the center of the rotation.
1 Assignment
0 Petitions
Accused Products
Abstract
The invention relates to a method and apparatus for manufacturing paper or like products which contains retention agent and inorganic filler. The retention and technical properties of the paper are enhanced by coflocculating the filler with a cellulosic material having a large specific surface area (fine pulp) prior to introducing floc suspension into the stock, and by subjecting the flocs to a floc size-controlling shearing process in a particular reaction vessel to produce flocs that have a mean particle size within the range of 2-4 mm. The particular reaction vessel used herefor incorporates a mixing zone, a flocculation zone, separator means located between the mixing zone and flocculation zone, a shearing zone and a sedimentation zone.
87 Citations
19 Claims
-
1. A method of manufacturing paper using a paper machine in which stock is fed to a headbox of said machine to form the paper, said method comprising the steps of:
-
introducing filler and pulp containing a high proportion of pulp fines into a reaction vessel; mixing said filler with said pulp containing a high proportion of pulp fines in said reaction vessel to form a resultant mixture; admixing the resultant mixture with retention agent in said reaction vessel to form flocs which contain the filler and said pulp containing a high proportion of pulp fines (coflocculation); subjecting the flocs to a size-controlling shearing process in said reaction vessel for breaking down large flocs and agglomerating small flocs to form flocs having a mean particle size in a range of 2 to 4 mm; and feeding the flocs to the stock upstream of the headbox, wherein the size-controlling shearing process is effected in a shearing zone in the reaction vessel in which the floc suspension is imparted with a helical rotational motion in the flow direction thereby engendering a controllable shearing effect between adjacent layers at varying distances from the center of the rotation. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
Specification