The raw material of the bamboo pulp paper holder is only about 1% of the pulp of the paper fiber. After the wet paper sheet is formed, the moisture content of the wet paper sheet must be reduced to 55% by mechanical exploitation. 65-75%, it is difficult to reduce the water content by mechanical methods.
In the production process of paper trays, about 3.5-4.5KG of water is removed per kilogram of bamboo pulp paper trays through the drying process. Therefore, drying is an important technological process in the production process of the paper tray, and the production cost of the drying process occupies a large proportion in the production of the paper tray. Increasing the drying efficiency of the paper tray is a key method to increase the production efficiency of the paper tray.
The wet paper mold with paper fiber as the main component is a porous object with a capillary structure inside. Moisture exists between the outer surface of the fibers and the pores of the fiber capillaries. Paper support products used for product inner packaging generally require excellent dynamic buffering performance, and the moisture in it cannot be removed by mechanical exploitation, but needs to be removed by drying methods. Thus, the drying strength of the pulp molded article is high compared to the conventional drying process of the sheet. On the one hand, hot air acts as a heat source to provide energy for transpiring water, and on the other hand, it acts as a water carrier to take away the continuously evaporated water.
The removal of moisture in the wet paper tray depends on the internal and external dispersion of moisture. The so-called internal dispersion refers to the migration process of moisture in the wet paper tray from the inside to the outside; process of walking. The unevenness of the dry rate of the paper tray depends on the moisture content, the speed of external dispersion and the balance and harmony between the two. The reasonable process conditions should be formulated around the above two aspects and the dry physical properties of the paper tray product.
After the bamboo pulp paper support product is vacuum-adsorbed and formed, there are three ways that water exists in the wet paper fiber: bound water, adsorbed water and free water. The purpose of the dry paper support product is to remove the free moisture in it, so that the bamboo pulp paper support can reach the equilibrium moisture content.
The drying mechanism of the paper tray is that when the water vapor pressure on the surface of the wet paper tray is greater than the partial pressure of the water vapor in the drying medium, the moisture on the surface of the wet blank will continuously vaporize and enter the air, and the moisture in the wet blank will continue to disperse to its surface. The speed of vaporization and dispersion varies with the temperature of the medium, the moisture content of the wet blank, the thickness and size of the paper holder, etc.
