RU1784468C - Method of cleaning glossed sheets in wood fiber plate industry - Google Patents

Abstract

Usage: in the woodworking industry in the production of fiberboards in the wet way. SUMMARY OF THE INVENTION: the method includes processing sheets in a hot press and removing carbon deposits from them without removing sheets. The sheets are treated with the surface of a fibrous carpet with a 20% aqueous solution of terpene maleoleum, saponified with caustic soda in an amount of 70-200 g per 1 m of carpet, applied before pressing. Jagar removal is carried out on the surface of the carpet. 1 tab

Description

The invention relates to the woodworking industry, in particular to the production of fiberboards (WFD) by the wet method.

The closest to the claimed technical essence and the achieved result is a method of cleaning glossy sheets, which consists in hydrothermally processing the glossy sheets in a press for pressing for 2-5 hours at 45; 6 & 0C. a pressure of 0.05-0.2 MPa soaked for 15-40 minutes with a 4-10% aqueous solution of caustic soda of wood-fiber boards. Carbon deposits are removed from the surface of the gloss sheets by a stream of water.

The disadvantage of this method is the loss of fiberboard and the complexity of the process due to the long shutdown of the process stream during the cleaning operation

The purpose of the invention is to increase the service life and the elimination of the shutdown of the process stream

This goal is achieved in that in the method of cleaning glossy sheets in the manufacture of fiberboards by removing carbon deposits without removing sheets, carbon deposits are removed by the surface of a fibrous carpet coated with 20% aqueous solution of terpenomaleic resin saponified with sodium hydroxide before pressing the amount of 70-200 g per 1 m of carpet.

The composition and properties of the terpenomaleic resin are regulated by TU 13-0281078-175-90. The terpenomalein resin is a yellow-to-yellow transparent glassy substance that in appearance crushes rosin. The acid number is not less than 250 mg KOH per 1 g of product, the softening temperature is not lower than 60 ° С, and the mass fraction of unsaponifiable substances is not more than 8%. Terpenomalienne resin is used to prepare curing agents and epoxies, terpenomaleimides used as

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tackifying agent for polar elastomers.

Example 1. On a wood fiber carpet with a humidity of 72%, obtained by wet method from a suspension of wood fibers according to the standard technological regime without the addition of a paraffin emulsion, a 20% aqueous solution of terpenomalein resin in the amount of 70 g per 1 m on top is applied - carpet, the Wood-fiber carpet is fed into a hot press, equipped with gloss sheets that can withstand more than 1100 pressing cycles with carbon deposits on the surface. Pressing is carried out at 195 ° C, with a maximum specific pressure of 5.5 MPa for 8 minutes. This press is opened, the plates are unloaded, subjected to heat treatment for 3 hours at 160 ° C and tested according to GOST 4598-86. Glossy sheets are subjected to external inspection.

Example 2-5. The processing and pressing techniques of the fiber carpet are similar to Example 1, and the flow rate of a 20% aqueous solution of terpenomaleic resin saponified with caustic soda is shown in the table.

Example 6. Differs from example 1 in that a solution of terpene-maleic resin is not applied to the surface of the wood-fiber carpet.

The test results are shown in the table.

As can be seen from the data given in the table, the application of terpene solution

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of a new resin provides cleaning of glossy sheets, while also promoting the hydrophobization of the surface of the plates. Application of a less than 70 g / m2 terpenomaleic resin significantly prolongs the cleaning time and reduces the hydrophobic surface properties of the boards. An increase in the consumption of terpenomaleic resin above 200 g / m2 does not lead to a reduction in the time taken to remove soot and does not provide a further decrease in water absorption of the surface of the plates.

The invention allows to significantly simplify the technology for cleaning contaminated surfaces of gloss sheets, eliminates the need to use fiberboard for cleaning, and eliminates the need to stop the processing line for cleaning gloss sheets.

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Claims (1)

SUMMARY OF THE INVENTION A method for cleaning glossy sheets of wood fiber board production, comprising treating sheets in a hot press and removing carbon deposits from them without removing sheets, characterized in that, in order to increase the service life and prevent the flow from stopping, the sheets are treated with the surface of a fibrous carpet with a 20% aqueous solution of terpenomalein resin saponified with caustic soda, applied to it before pressing, in an amount of 70-200 g per 1 m2 of carpet, they are removed to the surface to remove carbon deposits carpet.