Abstract: A test method for analyzing an OCC fiber pulp, to quantify the content therein of contaminants creating bleed-throughs in a paper product formed from the pulp. A sample of the pulp is formed into a sheet, and bleed-throughs are created from the contaminants therein by hot-pressing the sheet. A dye is applied to the sheet, to enhance contrast between areas of the sheet having bleed-throughs and areas of the sheet not having bleed-throughs. The contrasted sheet is analyzed to determine the quantity of contaminants that create bleed-throughs.

Abstract: A test method for analyzing an OCC fiber pulp, to quantify the content therein of contaminants creating bleed-throughs in a paper product formed from the pulp. A sample of the pulp is formed into a sheet, and bleed-throughs are created from the contaminants therein by hot-pressing the sheet. A dye is applied to the sheet, to enhance contrast between areas of the sheet having bleed-throughs and areas of the sheet not having bleed-throughs. The contrasted sheet is analyzed to determine the quantity of contaminants that create bleed-throughs.

Abstract: A system for removing bleed-through contaminants from OCC fiber pulp includes a plurality of primary flotation cells, with each primary flotation cell having an inlet, an accept outlet and a reject outlet. The inlet and the accept outlets of the plurality of primary flotation cells are coupled together in a series configuration. The reject outlets are coupled together in parallel. A secondary flotation cell has an inlet, at least one accept outlet and a reject outlet. The secondary flotation cell inlet is fluidly coupled with the reject outlet of the primary flotation cells. A water clarifier has an inlet, a clarified water outlet and a sludge outlet. The inlet is connected with the reject outlet of the secondary flotation cell.

Abstract: A flotation machine is provided which includes at least one flotation cell having an inner chamber. The fiber suspension is transported into the inner chamber, and a gas is injected into the fiber suspension within the inner chamber at a temperature below 20° C. to cause the wax to clump within the fiber suspension. The clumped wax is removed from the fiber suspension.

Abstract: A flotation machine is provided which includes at least one flotation cell having an inner chamber. The fiber suspension is transported into the inner chamber, and a gas is injected into the fiber suspension within the inner chamber at a temperature above 100° C. to decrease the density of the wax within the fiber suspension. The wax is removed from the fiber suspension.