SU1745712A1 - Stock for manufacturing gypsum-boards - Google Patents

Abstract

Used in the building materials industry. SUMMARY OF THE INVENTION 1 The raw mix for making gypsum sheets contains, in wt.%, Sodium salts of secondary alkyl sulfates, 0.02-0.03, fiberglass 0.02-0.04, starch paste (on a dry basis) 0.06- 0.10, protein modifier from chromic leather wastes (on a dry basis) 0.20-0.40, calcium sulphate hemihydrate else. The prepared starch paste is mixed with sodium salt of secondary alkyl sulfates and a modifier, the resulting aqueous solution is mixed with calcium sulfate hemihydrate and glass fiber, and the product is molded from the resulting raw mixture. The strength of the gypsum core 67 kgf / cm 2 table

Description

The invention relates to molding compounds and can be used in the building materials industry in the manufacture of gypsum sheets of sheets intended for wall finishing, partitioning and suspended ceilings.

The known raw material mixture for the manufacture of gypsum sheets (gypsum plasterboard), containing gypsum, reinforcing fiber, a foaming agent and starch. However, such a mixture, despite the high consumption of starch, does not provide the required physical and mechanical properties, and before entering the mixture, the starch must be subjected to further processing — grinding to a specific surface area of 10,000–20,000 cm / g.

Closest to the invention is the raw mix for the manufacture of gypsum sheets of composition, wt.%: A foaming agent 0.03. .0,10 reinforcing

fiber 0.1..2.0, starch 0.2 ... 0.5, calcium sulphate hemihydrate else,

The disadvantages of the known raw material mixture - low strength properties of products at high cost, which limits the use of gypsum sheets in construction

The purpose of the invention is to increase the strength and reduce the cost.

The proposed raw mix for the manufacture of gypsum sheets, including calcium sulfate hemihydrate, sodium salts of secondary alkyl sulfates, fiberglass, and an additive, contains starch paste and protein modifier from waste chrome leather as an additive in the following ratio of components, wt. %:

Sodium salts of secondary alkyl sulfates 0.02 0.03 Fiberglass0.02 0.04

Xi

sl xj

to

Starch paste (on dry basis) 0.06, .. 0.10 Protein modifier from chromic leather wastes (on dry substance) 0.20., .0.40 / Calcium sulfate hemihydrate Else

PRI me R. As raw materials take / 3-hemihydrate of calcium sulfate brand G-4B11 (normal hardening, medium grinding) according to GOST 125-79, sodium salts of secondary alkyl sulfates with a content of 30 wt.% Surfactant according to TU 38-10719- 77, fiberglass with a length of yarns 5 .., 20 mm, obtained from roving according to GOST 17139-79, starch paste made from starch according to GOST 7697-82 and modifier 1or from chrome leather wastes according to TU 17 SSR 15-04-86 obtained by processing chrome chips and trimmings, which are waste of the leather and footwear industry, solution of soda ash in the presence of ammonia. The modifier has a composition, wt.%; proteins, sodium chloid 0.04-0.08. Calla hydroxide., 2-3, sulfates 1-2, water the rest.

The raw mix is prepared as follows,

Initially prepared starch paste. Then an aqueous solution of liquid additives (sodium salt of secondary alkyl sulfates, starch paste, modifier from chrome-leather waste) is obtained, which is combined with calcium sulfate hemihydrate and fiberglass and mixed until uniform. The molding sand ratio is 0.7. From the prepared mixtures molded products, dried and subjected to tests,

Compositions of mixtures and technical and economic showed are given in table. 1 and 2.

The use of the proposed raw mix for the manufacture of gypsum sheets provides, compared with the known mixture, the following advantages: an increase by 25 ... 40% in strength when

compression of the gypsum core, which allows to reduce technological losses and scrap products;

an increase by 26 ... 60% of the destructive force during bending of gypsum sheets, which improves the deformative properties and expands the range of application of the products;

increase the elasticity and flexibility of gypsum sheets, which improves the portability and performance of products;

2 ... 3 times reduction in the consumption of scarce starch and involvement in the production of waste leather and footwear production, which makes it possible to reduce the cost of the finished product by 9, 17%

Claims (1)

Invention Formula Raw materials for making gypsum plasterboards, including calcium sulfate hemihydrate, sodium salts of secondary alkyl sulfates, fiberglass, and an additive that, in order to increase strength and reduce cost, it contains as an additive starch paste and a protein modifier from Chrome leather waste in the following ratio of components, May% Sodium salts of secondary alkyl sulfages 0.02-0.03 Fiberglass0.02-0.04 Starch paste (dry basis) 0.06-0.10 Protein modifier from waste chrome leather (dry basis) 0.20-0.40 / - sulfate hemihydrate Calcium Else. Table 1 table 2