Zur Mechanik der mehrschichtigen Spanplatte

Summary

With a view to the economic importance of multi-layer sandwich boards and plastic layer boards from wood base materials their physical and mechanical principles are explained and, taking three-layer particle boards as example, compared with experimental results in their application.

The determination of the thickness of surface layers on particle boards and the control of their variance by statistical methods is described. With the obtained mean value of the thickness of the surface layer the shelling ratio of three layer boards can be laid down in numbers, which is necessary for calculating the resulting properties of the whole board from the properties of its individual layers.

These connections are examined with reference to density, moisture content, resin content, modulus of elasticity, shear modulus of elasticity, stress and strain characteristics, tensile-, compression-, bending and tensile strength across the board. As was to be anticipated, the most charateristic property of a good three-layer board is a relatively high bendingand shearing stiffness. this favourable shelling effect for the use properties of the board is obtained the more completely, the better the construction of the board (shelling effect, density of the layers) and the elastic properties of the layers are adjusted to earch other.