18 ANDRITZ
Pulp Paper & Logistics
Output material after the post-shredding stage 3
optimising the management of paper throughout the value chain, from paper and board manufacturing, converting and printing, through to the collection, sorting, transportation, and recycling of used paper and board products back into the paper loop. For paper production based
on recycled fibres, waste paper is usually delivered as pressed bales held in shape with binding wires. These tied bales of waste paper are fed into the primary pulper. The plastics films, textile remnants, binding wires, and similar items fed to the plant together with the waste paper are considered contaminants in papermaking. They occur in the form of pulper rags and loose rejects. The rags especially, however, are also a valuable source of raw materials due to their very high steel wire content. Pulper rags form in the
July/August 2017
vortex center of the pulper from the bale wires and other contaminants and are removed from the pulper continuously by an adjustable ragger. The pulper rag is then cut into transportable lengths by a rag cutter. Pulper rags are a very demanding mechanical collection of metallic and non-metallic components. Rope lengths of up to 15m are not uncommon, and diameters can be up to 800mm. Steel wires with a diameter of around 3mm are the main valuable fraction that can be recovered from pulper rag recycling. Plastic films, textiles, and the residual organic waste are suitable for use as substitute fuels. Possible contaminants are non-ferrous metals in the form of aluminium foil or copper and aluminium wires as well as thick-walled steel parts, chunks of building rubble, and stones. The wealth of experience
Universal Granulator UG for post-shredding
gathered in recycling of pulper rags also shows that the material composition and structure of the
rags can vary considerably. For tasks as demanding as the treatment of pulper rags, a two-
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