SU1409703A1 - Method of producing facing board for gypsum cardboard sheets - Google Patents

Abstract

The invention relates to the pulp and paper industry and improves consumer duality of cardboard by increasing its roughness on the side adjacent to the gypsum core. The cover layer of the cardboard is formed from sulphate unbleached pulp, glued with rosin glue. Middle layers. molded from waste mass of mixed grades, glued with rosin glue. The bottom layer of cardboard is molded from sul-. fatny pulp from sawdust and waste sor- 3. pulp or from a mixture with other fibrous semi-finished products. (// Mass for the lower layer is glued with rosin glue. 1 tab.

Description

The invention relates to a multi-layer cladding technology for gypsum sheets used in construction, and is intended for use in pulp and paper industry. in the production of facing cardboard.

: The aim of the invention is to improve the consumer properties of the cardboard.

SUMMARY OF THE INVENTION The essence of the invention is that the bottom layer of multi-layer cladding cardboard is molded from sulphate pulp from sawdust and waste sorting pulp or from a mixture of it with other fibrous semi-finished products.

Example 1. Facing cardboard is made as follows. The cover layer is formed from 100% unbleached sulphate pulp, which is dissolved in a pulper at a concentration of 40 g / l and pumped to the pool. Then the mass is sent for cleaning. The grinding of the mass is carried out on disk and conic mills, after which the mass enters the composite tank, where rosin glue is supplied in the amount of 3% of the mass of the layer. Alumina is fed to a mixing pump.

The required amount of mass then enters the engine pool, the mass concentration in which is 3.0–3.5%. Then the mass is fed through a concentration regulator with a mixing pump to the fine cleaning, then diluted with water to a concentration of 0.3-0.5% H is fed to vacuum formers KDM.

The compositional composition of medium {: loev cardboard consists of waste yassa cf gshannyh brands.

The waste paper is dispensed with s hydraulic divider, then fed to a magnetic bifarato.r, after which it enters the b basin. Then the mass is fed to (high concentration cleaners, where heavy contaminants are removed. The pulp is fed to the backsight of the pulsating mill, and then - the centrifugal sorting SC-2,6-01,; & then - by 3 steps clean the conical vortex conical cleanings, then to the SI-25-01 thickener, the thickened mass, if necessary, is donated for grinding into a super refiner, and into the composite tank, where

Q

five

0 5 o

five

0

H l

five

give rosin glue in the amount of 1% by weight of the layer.

The prepared waste mass with a concentration of 3.0-3.8% enters the engine pool, then through the concentration regulator - to the purification, then it is diluted to a concentration of 0.6-0.8% and fed to vacuum formers.

The preparation of the mass for the lower layer is carried out according to a scheme similar to the preparation of the mass for the middle layers. Grinding is carried out on an MDS-14 disc mill. The ground mass is collected in a composite tank, where glue is supplied in the amount of 1.8% by weight of the layer.

In the lower layer, the ratio of sulphate unbleached pulp and sulphate pulp from sawdust and cellulose sorting waste is, in weight, hours:

Sulfate is not white

pulp30

Sulfate is not white

sawdust pulp

and waste sorting

pulp70

Rosin glue

The table shows the quality indicators obtained cardboard.

Example 2. The preparation of the mass is carried out analogously to example 1. As a sizing agent, glue paste of rosin EMO is used. The ratio of components according to the layers is mA, h .: coating layer

Sulfate unbleached pulp100

Rosin glue 2.5 Middle layers

Waste paper weight of mixed brands 100 Rosin glue 0,8 Bottom layer

Sulfate non-bleached cellulose from sawdust and sorting waste 100- Rosin glue 1,5

Example 3 The preparation of the pulp is carried out analogously to Example 1. The quantitative ratio of pulp, waste pulp and pulp from sawdust and pulp screening waste is in hours.

Cover layer

Sulfate unbleached pulp

Rosin glue

Middle layers

Waste paper mass of mixed brands Rosin glue

bottom layer

Sulfate unbleached pulp

Sulphate unbleached pulp from sawdust and cellulose waste Rosin glue

PRI me R 4. The preparation is carried out in the same way. The quantitative ratio of the waste mass and the price of sawdust and waste of sortirose is by weight, wt.

Cover layer

Sulfate unbleached pulp

Rosin glue

Medium layer - Wasted mass of mixed brands Rosin glue

bottom layer

Sulfate unbleached pulp from sawdust and waste sorted pulp

Waste paper grades MC-4,5,670

Rosin glue 2.2 As can be seen from the data presented in the table, compared to cardboard made using the prototype method, the cardboard obtained using the proposed method has improved consumer properties, namely, a higher roughness ratio for the side of the cardboard adjacent to the gypsum core, with high absorption. The roughness index is also close to that of the cardboard of the Zhidachevsky CDC, however, the cardboard of the Zhidachevsky production is characterized by low absorption, which makes it difficult to process it in the production of gypsum plasterboard.

Claims (1)

The invention The method of manufacture of cardboard for plasterboard sheets ,. including the formation of elementary layers of cardboard from; glued fibrous mass, while the surface layer is molded from the pulp, and the middle layers - from waste paper Synthesizing the elementary layers into a cardboard sheet, pressing and drying, characterized in that, in order to improve the consumer properties of the cardboard, the lower layer is molded from sulphate pulp from sawdust and cellulose waste or from a mixture of other fibrous semi-finished products.