Manufacturing technique for moisture-proof middle, high-density pressed-fibre board

Abstract

The invention relates to a production technology of a moistureproof medium and high density fibre panel in the fibre panel production technology. The production technology comprises the working procedures of wood chip screening and washing, stewing, hot grinding, glue blending and spreading, drying, paving and molding, heat pressing, and cooling. The steam pressure for wood chip stewing after water-washing ranges from 0.70 to 0.80MPa, and the stewing time is 3 to 5 minutes; when the wood chip is processed through hot grinding defibrination, a water repellent substance is added in, and the pressure in a grinding chamber is lower than the pressure in a stewing cylinder, wherein, the weight of the water repellent substance is 1 to 1.5 percent of the dry fibre, and the pressure of the stewing cylinder is 0.01 to 0.02MPa; in the working procedure of glue blending and spreading, MDI modified urea formaldehyde resin adhesive and firming agents are added in, wherein, the weight of the MDI modified urea formaldehyde resin adhesive is 9 to 11 percent of the dry fibre, and the weight of the firming agents is 2 to 4 percent of the dry fibre; in the drying working procedure, the water ratio is 8 to 12 percent; parting medium of 1 to 2ml/m<2> is sprayed onto the upper surface and the lower surface of a plate blank before entering into the working procedure of heat pressing; then the heat pressing is acted to form the fibre panel. Moistureproof plank stuffs which are produced by the invention can prevent the moisture in air from intruding, the various indexes satisfy the national standards, the surface is smooth and regular, the secondary process is facilitated, and the production cost is lowered.

Description

Technical field: [0001] The invention belongs to the technical field of artificial board production, and in particular relates to a moisture-proof medium and high density fiberboard production process for preventing the thickness of the medium and high density fiberboard from increasing after absorbing water. Background technique [0002] At present, the production process of medium and high-density fiberboard mainly includes log chipping (or purchased wood chips), wood chip screening and cleaning, cooking, hot grinding, glue mixing, drying, pre-pressing, hot pressing, sawing, cooling and other processes. The thermal grinding and glue dispensing process lacks the necessary moisture-proof treatment measures, resulting in poor waterproof performance of the produced MDF. With the wide application of medium and high density fiberboards outdoors, people have higher and higher requirements for the moisture resistance of medium and high density fiberboards. Therefore, medium and hi...

AI Technical Summary

Problems solved by technology

The thermal grinding and glue dispensing process lacks the necessary moisture-proof treatment measures, resulting in poor waterproof performance of the produced MDF