Why Are The Layers Of Lengthened Multilayer Board Odd?
May 03, 2022
Multilayer boards generally have 3, 5, 7, 9, 11, 13, 15, 17, 19 and 21 layers. Why are they all odd layers?
The purpose of using odd layers is to maintain the stability of plywood structure.
The multilayer board has an intermediate core layer, and the thin plates on both sides are symmetrically arranged relative to the intermediate core layer. On the one hand, the thin plates on both sides are restrained by the core layer; On the other hand, the intermediate layer is also pressed by the outer two layers, so that it is not easy to curl.
And the multi-layer boards are overlapped and glued according to the wood texture, so that each layer of veneers is restrained from each other. If the double-layer number is adopted, the symmetrical balance will be broken and the deformation probability will be greatly increased. However, in actual production, it is possible to use two layers of veneers with the same grain direction as the intermediate layer. In this case, although the plywood is an even layer, the even layer plywood can still maintain structural stability because the veneer texture on both sides of the plywood is still symmetrically arranged. Therefore, the common plywood is odd layer, but the practice of excluding even layer is less.
