Die Eignung von Sägespänen zur Herstellung von Holzspanplatten

Summary

The morphological characteristics of a mixture of sawdust from spruce- and pinewood were determined in order to prove their technical utilization for particleboard manufacture. It could be confirmed by experiments that it is not possible, with regard to the morphological characteristics of sawdust, to produce medium-weight chipboard with a normal consumption of synthetic resin possessing satisfying technological properties compared to chipboard from flakes. (The bending strength was only 70 to 90 kp/cm²).

As particleboard from sawdust possesses a relatively high tensile strength perpendicular to the board surface, it was investigated whether and to which extent especially mediumweight boards with improved technological properties can be manufactured making use of the three-layer-system with flakes from sprucewood in the surface layer and sawdust in the middle layer. Boards of considerably increased bending strenght and of satisfying tensile strenght perpendicular to surface and thus of an increased overall suitability could be produced with surface layers of 20 to 40 per cent of the board weight and middle layers of 60 to 80 per cent of the board weight.

Further investigations dealt with the development of strength in boards made from mixtures of flakes and sawdust. The bending strength rose with an increase in flakes while the tensile strength perpendicular to surface decreased.

Boards were manufactured experimentally in the laboratory and semitechnically with the wind-layering system occording to previous propositions for utilization of sawdust for manufacture of light, thick particle board (density 0,3 to 0,4g/cm ³) and their properties determined. These properties would be satisfactory for building-boards. When manufacturing light, thick boards according to the three-layer-system with flakes in the surface layers, a further improvement in quality of such boards was obtained.