Method for preparing medium density fiberboard by using microwave to pre-heat

Abstract

The invention discloses a method for preparing a medium density fiberboard by using microwave to pre-heat. The method comprises the procedures of treating raw materials, preparing fibers, gluing the fibers, drying the fibers, paving and molding the fibers, pre-pressing and hotly pressing. The method also comprises a procedure for pre-heating a fiber plate blank by using the microwave between the procedure for pre-pressing and the procedure for hotly pressing. The procedure for pre-heating the fiber plate blank by using the microwave to pre-heat is used for rapidly pre-heating the pre-pressed fiber plate blank by using the microwave through arranging a continuous tunnel type microwave heating device and the temperature of the fiber plate blank which is pre-heated by the microwave is controlled in a range of 50-60 DEG C. With the adoption of the method provided by the invention, the time for hotly pressing and raising the temperature of the fiber plate blank can be reduced so that the whole preparation time of the medium density fiberboard is shortened, the production efficiency of the medium density fiberboard is improved and the energy is saved, and the quality of the medium density fiberboard product also can be improved and enhanced.

Description

technical field [0001] The invention relates to the technical field of fiberboard preparation, in particular to a method for preparing medium density fiberboards preheated by microwaves. Background technique [0002] Medium density fiberboard is a kind of man-made board made of wood fiber or other plant fiber, after raw material treatment, fiber separation, application of urea-formaldehyde resin or other suitable adhesives, drying, paving, pre-pressing, and hot pressing . According to the definition of the national standard (GB / T 11718-2009), the density of medium density fiberboard is generally in the range of 650-800 kg / m3, and it is mainly used for furniture, handicrafts and decorative parts. With the development of the economy and the improvement of people's living standards, MDF plays an important role in the development of the national economy and people's material life. The production and use of MDF is one of the important ways to save and efficiently utilize wood re...

AI Technical Summary

Problems solved by technology

In the preparation method of this kind of medium density fiberboard, the purpose of its pre-pressing process is to get rid of the air in the slab, prevent a large amount of air from escaping and breaking through the slab during hot pressing, so that the slab has a certain degree of compactness; the hot pressing process The purpose is to vaporize, evaporate, increase density and solidify the adhesive in the pre-pressed fiber rough slab under the joint action of heat and pressure. This process plays a decisive role in product quality and output; The hot-pressing process usually heats and presses the pre-pressed fiber blanks directly to prepare fiberboards through a hot-pressing machine. Since the temperature of the pre-pressed fiber blanks is basically the same as room temperature, the hot-pressing temperature in the hot-pressing process Usually at 180-220 ° C, so the pre-pressed fiber rough slab needs a heating process when it is hot-pressed in the hot-pressing machine in the hot-pressing process. The whole production process of fiberboard takes longer, which affects the production efficiency of fiberboard

And in the hot pressing process of preparing MDF, if the core layer temperature of the fiber rough slab cannot quickly reach above 100°C after entering the hot press, the fiber rough slab cannot be rapidly formed and solidified, so that the quality of the medium density fiberboard can reach less than required

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