Now manufacturers in the production of fire-proof board is a water heat treatment process, water heat treatment is to enhance the performance of fire-proof board products, but in this process there will be wood end radial cracking and ring cracking problems, this will affect the quality of fire-proof board, then fire-proof board in the water heat treatment when the reason for cracking? In fact, there are two reasons for the cracking of the fireproof board, as follows:

一、是在水热处理中，由于木材孔隙很多，导热能力很差，因此热量是由表面向逐渐传递，温度也是由表面向逐渐降低，形成温度梯度，这时如果加热速度过快，就会出现木材表面部分温度高，已受热膨胀，而木材内部温度较低，未膨胀或膨胀甚少的现象，当木材内部的应力超过了木材横纹方向的抗拉强度时，就引起木段端头的纵向开或是环状开裂，严重影响防火板的质量以及出板率。
             

1、 In the hydrothermal treatment, due to many pores and poor thermal conductivity of wood, the heat is gradually transferred from the surface to the center, and the temperature is also gradually reduced from the surface to the center, forming a temperature gradient. At this time, if the heating speed is too fast, the surface temperature of wood will be high, and it has been heated and expanded, while the internal temperature of wood is low, and it has not expanded or expanded very little When the stress inside the wood exceeds the tensile strength of the wood in the direction of transverse grain, it will cause the longitudinal opening or ring cracking of the end of the wood section, which will seriously affect the quality and yield of the fireproof board.

二、是木段从煮木池中取出，如果冷却速度过快，也是会产生同样的缺陷，出现这种缺陷以后的木材会影响防火板质量，导致防火板价格会受到较大的影响。

2、 If the cooling speed is too fast, the same defect will occur. The quality of fireproof board will be affected and the price of fireproof board will be greatly affected.

综上就要求所有的防火板在做水热处理的时候，一定是要控制好温度，谨防木材出现开裂的现象，进而影响防火板质量。

To sum up, it is required that the temperature of all fire-proof boards must be well controlled when they are subjected to hydrothermal treatment, so as to prevent the cracking of wood, which will affect the quality of fire-proof boards.