Determining optical properties of mechanical pulps : Sheetmaking procedure and investigation of different ways to evaluate light absorption

• A method to produce representative sheets for determination of optical properties of mechanical pulps has been developed. It reduces the risk of contamination and discoloration and can be used with small pulp quantities. The deviation from the expected linear behaviour of the light scattering coefficient, s, at wavelengths corresponding to strong light absorption, has been studied using the Kubelka-Munk model and the angular resolved DORT2002 radiative transfer solution method. This decrease in s could not be explained by errors introduced in the Kubelka-Munk modelling by anisotropic scattering. Linear extrapolation of s can therefore not be justified as a way to obtain a more correct light absorption coefficient, k. For thepulps studied, the decrease in s at short wavelengths had little effect on k at 457 nm.

Subject headings

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Keyword

Kubelka-Munk; Light absorption; Light scattering; Mechanical pulps; Optical modelling; Optical properties; Radiative transfer solution method; Sheet forming procedure

Chemical engineering

Kemiteknik

Publication and Content Type

ref (subject category)

art (subject category)