SU1348431A1 - Method of producing laminated cardboard - Google Patents

Abstract

The invention relates to the pulp and paper industry, which makes it possible to simplify the process and at the same time to increase the mechanical readability of the cardboard. A thermosetting binder is injected into a dry-shredded waste paper and a fibrous carpet is formed. Then the fibrous carpet is connected with two sheets of finished cardboard with glue, placing the carpet between the sheets of cardboard with simultaneous formation of a middle layer for 0, 7 minutes per 1 mm of the thickness of the finished glued cardboard during pressing and simultaneous drying. (L with 00 4 WITH

Description

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The invention relates to the production of multilayer glued cardboard, it can be used in pulp and paper and other industries that are engaged in the processing of paper, cardboard, waste paper into cardboard glue; machines for special purpose materials, construction, insulation, decorative, etc.

The aim of the invention is to simplify the process while simultaneously increasing the mechanical strength of the paperboard.

Example 1. The process of manufacturing a multilayer glued cardboard with a thickness of 6.5 mm and a density of 650 kg / m on a cardboard-gluing machine is modeled using a laboratory plate press. As the outer layers use a cardboard-based building cardboard weighing 700 g / m. Dry-shredded waste paper with a moisture content of 5% to a fraction of 3-20 mm while stirring it is treated with a solution of a thermosetting binder by spraying the latter in an amount of 8% of the dry residue from the absolutely dry mass of waste paper. A solution of a thermosetting binder is prepared on the basis of a carbamide-formaldehyde resin of the brand KF-MT-P and a 20% solution of ammonium chloride at a consumption of the latter of 1% of the dry residue of the mass of commercial (66%) resin.

Next, a fibrous carpet is molded by filling the blended waste paper treated with a binder into a mold, on the base of which the lower outer layer of cardboard base is preliminarily deposited on the surface with a roller of glue with a dry weight of 70 g / m based on the specified binder. and the molded carpet is laid the upper outer layer of cardboard base, processed similarly to the bottom, and placed in a press. The formation of the inner layer is carried out in the process of gluing the layers under the conditions of pressing with simultaneous drying at a maximum specific pressure of 1.2 MPa and a temperature of 140 ° C for 0.7 min per 1 mm of the thickness of the finished glued cardboard.

The total weight consumption of the binder of dry residue for the manufacture of glued cardboard was

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315 g / m, including the formation of the inner layer 185 g / m.

EXAMPLE 2. The process of manufacturing laminated laminated cardboard is carried out analogously to Example 1, but the processing of dry-ground waste paper is carried out with a solution of a thermosetting binder in an amount of 12% of the dry residue of the completely dry weight of waste paper. produced in the process of gluing the layers for 0.4 minutes per 1 mm of the thickness of the finished glued cardboard,

The total weight consumption of the binder on the dry residue in the manufacture of glued cardboard was 400 g / m, including 270 g / m for the formation of the inner layer.

EXAMPLE 3. The process of manufacturing laminated laminated cardboard is carried out analogously to Example 1, but a mixture of dry-crushed waste paper and sawdust with a fraction of 2-7 mm and a moisture content of 5% is used as the fibrous raw material for the inner layer. mixes respectively 1: 1.

EXAMPLE 4. The process of manufacturing laminated glued cardboard is carried out analogously to Example 3, but the processing of the fibrous raw material for the inner layer is carried out with a solution of a thermostatic binder prepared on the basis of a thermosetting carbamide-formaldehyde resin of the IF brand and a 20% solution of ammonium chloride at the expense of the last 1% on the dry rest to the mass of commodity (6%) pitch.

PRI me R 5 (prototype). Make a multilayer glued cardboard of the type of building thickness of 6.5 mm and a density of 650 kg / m. As a 4-intermediate layers of the inner layer of the construction paperboard, as well as its outer layers, we used a cardboard-base formed from the crushed waste paper on a carving machine using the wet method. Silicate glue (sodium liquid glass) was used as the adhesive. Its consumption of dry residue on each surface of the base cardboard facing each other was 40 g / m (total consumption 400 g / m). Bonding exterior and interior

layers are produced in a plate press, a model of gluing conditions in the dry-press part of a cardboard-gluing machine, namely: specific pressure 1.2 MPa, temperature, their exposure time is 30 s, which is calculated in terms of 1 mm thickness of glued cardboard 0 , 08 min.

The tensile strength in static bending in the transverse direction of a multi-ply cardboard made according to examples 1-5 is respectively 7.6; 8.9; 13.1; 13.0; 6.5 MPa

Using the proposed method of manufacturing a multi-layer glued cardboard provides a material with the best mechanical properties in terms of tensile strength in static bending, and hence stiffness.

In addition, while eliminating production waste — waste water, finely grained fiber, kaolin, printing ink, etc., characteristic of the wet method of making baseboard for the inner layer of glued cardboard, the process of implementing the proposed method is greatly simplified. the elimination of the stages of preparation of fibrous raw materials from waste paper

Editor N.Shvydka

Compiled by V. Shimanska

Tehred L. Serdyukova Proofreader A.Obruchar

Order 5169/28 Circulation 340 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, Projecto st., 4

348431

in the aquatic environment and the manufacture of baseboard for the inner layer on the board maker.

The proposed method also makes it possible to reduce energy consumption and labor intensity of production, to process moisture-resistant types of waste paper, including those impregnated with synthetic resins, which are not used as secondary raw materials. .

Claims (1)

Invention Formula ten A method of making a multi-layer cartoon, comprising forming an inner layer of fibrous mass based on crushed mackaurum and joining the outer fibrous layers to the inner layer with an adhesive during compression and simultaneous drying, in order to simplify the process while turning strength of the cardboard, the formation of the inner layer is carried out from dry-shredded waste paper with the formation of a fibrous carpet, and the connection of the layers is carried out during 0,4 - O, m is 1 mm laminated paperboard predetermined thickness.