Influence of the surface roughness of particleboards and their performance towards coating

Las propiedades de la superficie y su efecto en la calidad de la adhesion fueron evaluadas en tableros pintados. Tableros de partículas sin recubrir encolados con resinas UF y TF hechos utilizando diferentes materias primas fueron acondicionados a clima 20°C and 65 % de humedad relativa fueron pintados con un aparejo nitrocelulósico mediante un proceso convencional. La interacción entre el aparejo y la superficie parece ser un importante factor que determina la fuerza de la adherencia. AbstractThe effect of surface properties on the quality of the adhesion was evaluated for coated particleboards. Uncoated UF- and TF-bonded particleboards made using different raw materials were conditioned under 20°C and 65 % relative humidity and coated with a nitrocellulose lacquer primer by a conventional process. The interaction between the primer and surface seems to be a very important factor determining the strength of adherence

Einfluss der Aufschlusstemperatur auf die morphologischen Eigenschaften von TMP aus Kiefernholz

Chips from pine wood were subjected to thermomechanical pulping (TMP) at 140 and 180 degrees C for 5 minutes, whereas the cooked chips were defibrated using a single disk pressurized refiner at the same temperatures (140 and 180 degrees C). The fibres were tested for some of their morphological properties including fibre length, fibre width, cell-wall thickness. Moreover, the fine fibre fraction (zero fibres) and the content of splinters were also estimated. The results reveal, that increasing the temperature during thermomechanical pulping decreases the fibre length, the cell width and the fibre wall thickness. It also increases the amount of fine fibres and increases the curl factor