Influence of surface sprinkling on the heat-conduction of dry-process fiberboard under hot-pressing

The humidifying treatment in the mat surface was adopted during the hot-pressing process to make dry-process fiberboard under different conditions. The changes of temperature in the core layer and the surface of a mat were measured. Based on the analysis of the curves of changing temperatures, conclusions are as follows: 1) humidifying treatment in the mat surface of dry-process fiberboard has little effect on raising mat surface temperature. 2) humidifying treatment in the mat surface is not suitable for an adhesive whose curing temperature is above 120℃. It accelerates the speed of temperature increase before the temperature of the core layer reaches water vaporization point. 3) the speed of temperature increase of the core layer of the mat increases with the sprinkling amount of the mat surface, but the speed does not increase obviously when the sprinkling amount of the mat surface reaches an optimum level. The optimum sprinkling amount increases when the density or thickness of panels or hot-pressing temperature increases. 4) for the same sprinkling amount of the mat surface, the speed of temperature increase of the core of mat increases obviously when the density or thickness of a panel or sprinkling amount of the mat is low, while the temperature of hot-pressing has little effect on it. 5) humidifying treatment in the mat surface almost doubles the speed of core temperature increase of the mat.