仿古门窗是原木经过旋切或刨切成单板，再经纵横交错排列、胶合为三层或多层的板材。

Antique doors and windows are timber after peeling or sliced veneer, the bonding plate arrangement, arranged in a crisscross pattern of three or more layers.

为了消除木材本身的缺点，增强仿古门窗的特性，单板在组成仿古门窗时应遵守三个原则:对称层原则、奇数层原则、层的厚度原则，其中对称层原则是最基本的原则。

In order to eliminate the disadvantages of wood itself, enhance the characteristics of antique doors, single board should abide by three principles in the form of antique doors and windows: the thickness of layer principle, principle of symmetry principle, odd layer layer, which layer symmetry principle is the most basic principle.

1.对称层原则

Principle of 1 symmetrical layer

仿古门窗在对称平面的两边层数应相同，对称层的单板在厚度、树种、含水率、纤维方向及制造方法(旋制、刨制、锯制)等都必须相同，使仿古门窗的各种内应力保持相对平衡，以防翘曲变形。

Antique doors and windows in the plane of the layers symmetrical on both sides should be the same, the symmetry layer single plate in thickness, species, moisture content, fiber orientation and manufacturing methods (spinning, planing, sawing etc.) must be the same, the internal stress of antique doors and windows to maintain a relative balance, to prevent warping deformation.

2.奇数层原则

2 odd level principle

由于仿古门窗相邻层单板的纤维是相互垂直而且又是相互对称的，所以它的层数必须为奇数。单板为奇数的仿古门窗，对称平面必定与中心板的对称平面相重合，而偶数层仿古门窗对称平面则是胶层。实验证明，仿古门窗弯曲时最大水平剪切力作用于对称面上，故偶数层仿古门窗弯曲时最大剪应力不是作用在木材上，而是作用在胶层上。一般生产仿古门窗的胶钻剂，胶层的抗剪强度小于木材的抗剪强度，所以多层仿古门窗单板层数为奇数。

As the antique door and window adjacent layer veneer fiber is perpendicular to each other and is symmetrical, so its number of layers must be odd. Single board is an odd number of antique doors and windows, and the center symmetry plane will board the plane of symmetry coincide, and even layers of antique doors is a plane of symmetry layer. Experiments show that the maximum bending antique doors horizontal shear force on the plane of symmetry, so even layers of antique doors when bending the maximum shear stress is not effect on the wood, but in the layer. The general production of antique doors and windows of the glue drilling agent, shear strength is smaller than the wood layer, so the multilayer veneer layers for odd antique doors and windows.

3.厚度原则

3 thickness principle

同一厚度的仿古门窗可以用较厚而层数较少的单板组成，也可以用较薄而层数较多的单板组成。实验证明，单板越薄，层数越多，仿古门窗的质量越好，在顺纹和横纹两个方向的抗拉强度越趋于一致。但在实际生产中，厚度要受到机床加工精度、产品成本等各方面因素的制约，不可能生产单板太薄、层数较多的仿古门窗，故对厚度和层数要根据产品的用途作适当的选择。

The same thickness of antique doors and windows can be thicker and less layers of single board, you can also use thinner and more layers of single board composition. Experiments show that the single plate is thin, the more layers, the better the quality of antique doors and windows, more and more consistent in tensile strength parallel to grain and grain in two directions. But in the actual production, the thickness to various factors by the machining precision, product cost, cannot produce single plate is too thin, the more layers of antique doors and windows, so the thickness and layers to make appropriate choices according to the use of the products.