The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 22, 1999
Filed:
Dec. 17, 1996
Jyrki Kettunen, Kirkniemi, FI;
Jukka Ranua, Lohja, FI;
Metsa-Serla Oy, , FI;
Abstract
The present invention is related to a method of producing paper pulp from a fibrous raw material. According to the invention, such pulpwood is used in which the content of phenol compounds or phenolic derivatives is clearly, advantageously at least 20% lower than the average content of such compounds in the native grade of the raw material. Advantageously, the content of parahydroxy-benzoic acid (PHBA) is determined from the pulpwood and pulpwood containing low PHBA levels is used as pulping raw material. The invention also provides a method of producing pulp-wood suitable for use in the manufacture of easily bleachable paper pulp, in which method selected native specimens of pulpwood trees with an advantageously low content of phenol compounds or phenolic derivatives are produced by micropropagation, the cloned tree specimens are planted and grown to obtain pulping raw material, the pulpwood is harvested, and the pulpwood is produced into paper pulp using mechanical, chemical or chemimechanical delignification methods.