Abstract: The invention relates to a stabilizing composition comprising following components (A) a polymer having the following formula: wherein R1 is a hydrogen atom or an alkyl group containing 1 to 12 carbon atoms, R2 is —COOM or —CH2COOM, M is a hydrogen atom, an alkali metal ion, an alkaline earth metal ion, an ammonium ion or a mixture thereof, n, m and k are molar ratios of corresponding monomers, wherein n is 0 to 0.95, m is 0.05 to 0.9, and k is 0 to 0.8, and (n+m+k) equals 1, and the weight average molecular weight is between 500 and 20,000,000 g/mol, (B) a chelating agent, (C) a poly-alpha-hydroxyacrylic acid or an alkaline salt thereof or the corresponding polylactone thereof, and (D) optionally a polycarboxylic acid polymer or an alkaline salt thereof. The invention also relates to a process for the treatment of a fiber material.

Abstract: Methods for treating lignocellulosic material or pigment with a reductive bleaching solution generally include washing the lignocellulosic material or pigment with a reducing agent of magnesium dithionite. The method includes at least one reductive stage and at least one peroxide stage. Also disclosed are methods for preparing dithionite solution wherein magnesium bisulfite is reduced with borohydride solution to obtain dithionite. Bleached lignocellulosic material or pigment obtained with the treatment methods are also disclosed.

Abstract: The invention relates to a method for measuring the volume or the end face diameter of a tree trunk and for quality control. The volume is measured in a prior known manner with laser gauges capable of measuring top and butt diameters as well as a length, which are used for calculating a volume. For quality control, the end face of a tree trunk is illuminated with red light and blue light, and light coming from the end face of the tree trunk is received by a color matrix camera (5). From the red/blue ratio in the camera's (5) signals is identified the proportion of rot or other defect in the end face of a tree trunk. The camera signals can be used for calculating the end face diameters of tree trunks. The method is integrated with a pulpwood pretreatment process upstream of debarking.