Method for establishing moisture content gradient of shaving board

Abstract

The invention discloses a method for establishing a moisture content gradient of a shaving board. The method consists of three technological links, namely drying in levels, respective glue mixing and respective paving. The drying in levels is characterized in that two levels of drying systems are established and a shaving sorting procedure is set up between the first-level drying system and the second-level drying system; the shavings subjected to drying in levels are respectively stored, metered and mixed with glue, and the moisture content difference between shavings in a core layer and shavings on a surface layer are stabilized; after the shavings are metered, the shavings are respectively paved, and the moisture content gradient is finally established on a cross section of a blank of the shaving board. By the moisture content gradient, the moisture on the surface of the blank is quickly vaporized in the heating process, a steam impact effect is generated, the heat transfer speed is improved, the temperature rise speed of the core layer is improved and the aims of shortening hot-pressing time and improving hot-pressing efficiency are finally fulfilled; in addition, by establishing the moisture content gradient of the blank, the performance and the surface quality of the finished shaving board can be obviously improved, the static bending intensity of the board is improved, the made shaving board is more smooth in surface, and the sanding loss of the shaving board is reduced.

Description

technical field [0001] The invention relates to a method for constructing a moisture content gradient of a particleboard, which is mainly used in the production of the particleboard and belongs to the technical field of wood processing. Background technique [0002] Hot pressing is the most important process in the production of particleboard. Its main functions include two aspects: (1) compressing the slab to a specified thickness; (2) promoting the curing of the resin to form a bonding strength. Among them, the curing time of the resin is the main basis for determining the hot-pressing cycle of the particle board, and thus also determines the efficiency of the particle board production line. In the production of particleboard, the resin is cured at a certain temperature. Since the core layer of the particleboard slab reaches the temperature required for resin curing later than the surface layer, the hot pressing time mainly depends on the heating rate of the core layer o...

AI Technical Summary

Problems solved by technology

The shape of the shavings has a significant impact on the drying rate. Since the moisture in the wood is mainly evaporated through the surface, the thickness of the shavings, which is closely related to the water diffusion resistance and distance, becomes the key to the drying rate. The thicker the shavings, the longer the drying time. However, under the same drying conditions, large-sized shavings often require longer drying time and consume more energy

At present, most of the shavings are dried at the same time, and the size of the shavings is not distinguished. This method not only consumes a lot of energy, but is also not conducive to improving the drying quality of the shavings.