Finnish inventors develop pulp quality control method

Jul 28, 2006. /Lesprom Network/. Ari Ammala and Jouko Niinimaki, both of Oulu, Finland and Tero Jussila of Tampere, Finland, have developed a method for controlling screening by measuring flow amount consistency of the pulp, US Fed News said. According to the U.S. Patent & Trademark Office: "The invention relates to a method of controlling quality of pulp. Pulp formed in mechanical defibering of wood is screened into at least two fractions, the accept that has passed the screening phase being forwarded for further use and the reject that did not pass the screening being removed from the screening phase." An abstract of the invention, released by the Patent Office, said: "The invention comprises determining flow amount and consistency of the pulp supplied to the screening phase and, correspondingly, of the reject removed therefrom, and calculating a passage ratio of the reject and the supplied pulp by means of the flow amounts and consistency values verified through the measurement, and adjusting the screening phase according to said passage ratio." The inventors were issued U.S. Patent № 7,077,930 on July 18. The patent has been assigned to Metso Paper Inc., Helsinki, Finland.