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Pulp Manufactoring Process

  • A mix of the following types of wood is used for the production of bleached kraft pulp: beech, oak, acacia and poplar. The logs, delivered to the production site, are subject to the following treatment: debarking, cutting in order to obtain chips, sorting and transportation.

  • Standard-size chips (45 x 45 x 10 mm) shall be submitted for boiling in purpose-built digesters.

  • After filling of the digesters, the chips are flooded with boiling liquor containing mainly NaOH and Na2S. The cooking process lasts 4 hours. The goal is to destroy the structure of the wood as lignin, hemicellulose and other high molecular weight compounds pass into a solution, but the cellulose fibers remain solid.

  • The resulting pulp contains both mechanical impurities, received by the boiling solution or finished wood chips, and raw wood residues called "impurities". Therefore, it is subject to a two-stage screening - coarse and fine, in order to complete the separation of the impurities and the rejects from the cellulose. The purpose of the washing process is to extract, from the cellulose, all the dissolved during digesting organic matter (black liquor), as well as the rest of the alkali from the boiling liquor. The washing is done with hot water through an installation called "Chemi washer". The main goal, in the bleaching process, is to remove the remaining lignin from the cellulose fibers. The process occurs in four distinct stages in the following order: O2 - D0 - EOP - D1. After each stage the pulp is subject to an intermediate washing in order to remove the products of bleaching.

  • After wire section (wet end) the dry content of the pulp web is 20-24 %, after pressing it reaches 48-50 %, and after drying the residual moisture is 10-13 %.

  • The width of the pulp web, at the output of drying section, is 4200 mm.

  • After the drying section the pulp web is cut longitudinally and transversely into sheets with size 600x850 mm.

  • On the last stage we have the processes of pressing, packaging and the final formation of packages of 4 bales each, with a total weight of 1080 kg per package.