method for separately be recycled by a semi chemical fiberfraktion forming a korrugeringsmedium and a fraction of kraftfibrer forming a linerboard in corrugated paper

摘要

1432650 Processing waste corrugated board ARTHUR D LITTLE INC 21 Sept 1973 [25 Sept 1972] 44420/73 Heading D2A A method of separating the semichemical fibre fraction forming the corrugated medium from the kraft fibre fraction forming the linerboard or waste corrugated board comprises the steps of reducing the corrugated board stock to pieces of intermediate size, dispersing the pieces in water, subjecting the pieces in water to differential size reduction by mechanical action to separate the corrugated medium from the liner board and to reduce it to small pieces or fibres while the linerboard remains in the form of larger pieces, and separating the fibres and small pieces of the corrugated medium from the linerboard pieces. The waste board is preferably sorted to remove extraneous material before being reduced to pieces of intermediate size, the pieces preferably having dimension of 1 to 6 inches. During the size reduction, a debonding agent such as water, urea and/or ethylene carbonate, or a surfactant may be present. The size reduction may be carried out in a hammermill or a rotary cutter may be used. During the differential size reduction, the water may contain ¢ to 10% of its weight of the pieces and up to 0.3% of its weight of a surfactant, and the temperature may be up to 160‹F. The differential size reduction may be carried out in a pulper, a propeller type mixer or a ball mill in batches, or continuously in a pipeline type mixer or a continuous ball mill. The corrugated medium may be reduced to pieces of sizes up to #'' The separation of the corrugated medium from the linerboard may be carried out by screening or by flotation.