SU1724777A1 - Method of producing fibreboard - Google Patents

Abstract

SUMMARY OF THE INVENTION: In a fiber manufacturing method comprising impregnating a base paper with a parchment solution, forming a monolithic web from the impregnated paper layers, washing with a parchment solution, impregnating the raw fiber with a flame retardant solution, drying and pressing, a mixture of phosphoric acid is used as a flame retardant, aluminum hydroxide and carbamide with a molar ratio of the starting components in terms of the elements P: AI: N, equal to 2.00: (0.20-0.47) :( 0.80-2.00), and drying the fibers is carried out at 115-150 ° C. 1 tab.

Description

This invention relates to the pulp and paper industry, in particular to fiber production.

A known method of producing fiber includes impregnating a base paper made from purified cotton or wood pulp, a concentrated solution of zinc chloride, forming a layered material, aging, washing with water, drying on a special device with a 100% moisture content, impregnating the material with an aqueous solution of complex phosphoric acid ester, consisting of formaldehyde dicyandiamide and phosphoric acid, drying the fiber in a multi-cylinder dryer at a temperature not higher than 100 ° C.

The disadvantage of the method is the unsatisfactory fire resistance of the fiber, the duration and multistage of the process.

The closest to the present invention is a method of producing a flame retardant fiber, including impregnating the base paper with a solution of zinc chloride, forming a multilayer cloth 0.5 mm thick, continuously washing the fiber with water, impregnating the material for 6 minutes with an aqueous solution of a fire retardant preparation containing condensed phosphate alkyl alkyl ether acids, guanidine phosphate, denaturated phosphate acids organic salts of sulfamic acid or phosphoric dicyanamide formaldehyde ether at t the temperature of the solutions is 40 ° C, the concentration is about 20% and the pH is 5.5-7.0, drying the fibers on a drum dryer for 30 minutes at 110 ° C.

The disadvantage of this method is insufficient fire resistance, low dielectric properties and mechanical strength of the fiber.

SP

WITH

vi

to

VI s VI

The purpose of the invention is to improve the fire resistance and improve the quality of the fiber.

The goal is achieved in that according to the method of obtaining the fiber, which includes impregnating the base paper with a parchment solution, forming a monolithic web from the impregnated paper layers, washing off the parchment solution, impregnating the raw fiber with a flame retardant solution, drying and pressing, the mixture is used as a flame retardant solution phosphoric acid, aluminum hydroxide and carbamide with a molar ratio of the starting components in terms of elements P: AI: N, equal to 2.00: (0.20 - 0.47) :( 0.80-2.00), and drying fibers are performed at 1 15-150 ° C.

EXAMPLE 1 To prepare a flame retardant impregnating solution, a pulp is prepared based on a molar ratio of 00: 0.47: 0.80. For this, 18.60 g of aluminum hydroxide is dissolved in 100 g of phosphoric acid with a concentration of 50 wt. % at 100 ° C. 12.20 g of urea are added to this solution, cooled to 40 ° C, and, after vigorous stirring, diluted with water (0.15 L) to obtain a 20% solution. The resulting solution is poured into the impregnation bath, which receives the cheese fiber with a thickness of 1 mm. In the bath, the fiber is impregnated with a flame retardant solution at 20 ° C for 20-30 seconds, after which the monolithic fiber layer is dried on a drum dryer at 115 ° C and pressed at a pressure of 1-2 MPa and a press temperature of 80-120 ° C.

Examples with different ratios of components of flame retardant impregnation and those

five

0

five

0

five

Perura drying fiber, as well as quality indicators obtained fiber are shown in the table.

Tests of the obtained fiber to determine the tensile strength, specific volume electrical resistance, and electrical strength were carried out in accordance with GOST 14613-83, fire resistance (burning criteria) according to GOST 12.1.044.84.

Using the proposed method of obtaining fiber, in addition to improving the fire resistance and improving the quality of the material, has the following advantages compared with the known methods: the use of non-deficient raw materials, shortening the process time and intensifying the process by increasing the drying temperature of the fiber.

Claims (1)

Invention Formula A method of making a fiber comprising impregnating the base paper with a parchment solution, forming a monolithic web from the impregnated paper layers, washing off the parchment solution, impregnating the raw fiber with a flame retardant solution, drying and pressing, in order to improve the fire resistance and improve the quality of the fiber , as a flame retardant solution, a mixture of phosphoric acid, aluminum hydroxide and urea is used with a molar ratio of the starting components in terms of the elements P: Al: N, equal to 2.00: (0.20- 0.47) :( 0.80- 2.00), and the drying of the fiber is carried out at 115-150 ° C.  at;;; to; n; Gk; yy "nG" about SG and sample w. “..