RU2843414C1 - Method of producing gypsum-thermowood composition - Google Patents

Abstract

FIELD: performing operations.

SUBSTANCE: invention relates to production of construction material and can be used for making gypsum-thermowood blocks and boards. Method of manufacturing a gypsum-thermowood composition is carried out by filling a sealed open-top mould with crushed thermally modified wood while adding a solution of gypsum and water, compaction of obtained composition in a mould using a perforated plate-puncheon, by means of its movement from top to bottom with simultaneous operation of the vibrator, holding the composition in a compressed state until setting of the gypsum solution and removing the plate-puncheon with excess solution on its upper part. Gypsum-thermowood mixture has the following ratio of components, vol. %: gypsum 23, water 23, filler in form of said ground thermally modified wood 54.

EFFECT: invention reduces properties of the organic filler which negatively affect the gypsum-wood composition, reduces consumption of gypsum binder and mass of thermowood compositions, and improves heat-protective and sound-insulating properties of the finished material.

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Description

The invention relates to the technology of producing building materials and can be used for the production of gypsum-thermowood blocks and slabs intended for use indoors as partitions, dry screeds and cladding, possessing low density (low weight), high heat-protective and sound-insulating properties.

A method for producing a gypsum concrete mixture is known [1], based on the use of gypsum binder, organic fillers in the form of waste paper, wood fiber, flax shives, wood sawdust and shavings with the addition of a mineral filler in the form of clay shale to increase the strength of the finished product.

The main disadvantage of gypsum concrete and other gypsum-based building materials is their low moisture resistance. At the same time, along with the economic efficiency of using organic fillers in the material, the strength and moisture resistance indicators are significantly reduced compared to gypsum concrete on mineral fillers. The main disadvantage is the high moisture and water absorption rates of wood and other organic fillers, as well as their ability to retain water for a long time.

A method for producing thermally modified wood concrete (hereinafter referred to as TWC) using thermally modified wood (TMW) as a filler is known [2]. The material is produced using TMD fillers with sizes of 5-40 mm, thermal modification of the filler is carried out in a steam-air environment, followed by washing with water and treatment in a 5% aqueous solution of polyvinyl acetate emulsion for at least 30 minutes. The molding of the thermally modified wood concrete mixture is carried out by vibration casting or vibration pressing, followed by aging under natural conditions or in steam-air chambers with heat and moisture treatment, the preparation of the thermally modified wood concrete mixture is carried out immediately after treatment with the said solution.

The disadvantage of this method is that thermal wood concrete products obtained on the basis of cement binders have a higher density, lower heat-protective and sound-insulating properties compared to gypsum binders. Also, the disadvantages of cement-based materials include the setting and maturation time of products during the production process. This method is taken as a prototype.

The technical result consists in reducing the properties of the organic filler that negatively affect the gypsum-wood composition by using a stabilized thermally modified wood filler with reduced water and moisture absorption and an equilibrium moisture index, as well as in reducing the consumption of gypsum binders and the mass (density) of thermally modified wood compositions, and increasing the heat-protective and sound-insulating properties of the finished material.

The technical result is achieved in that the gypsum-thermowood composition is obtained by filling a sealed open-top mold with crushed thermally modified wood while simultaneously adding a gypsum solution and water, compacting the resulting composition in the mold using a perforated punch plate by moving it from top to bottom while simultaneously operating a vibrator, maintaining the composition in a compressed state until the gypsum solution sets and removing the punch plate with excess solution on its upper part, the gypsum-thermowood mixture has a component ratio, vol. %: gypsum 23, water 23, filler in the form of said crushed thermally modified wood 54.

The method for producing gypsum-thermowood composition consists of the following stages:

1. Obtaining wood filler with established dimensions in crushing plants.

2. Drying and thermal modification of the filler in specialized installations for thermal modification of wood.

3. Preparation of gypsum-thermowood composition in the proposed quantitative and qualitative composition and molding. Molding is carried out by vibration pressing using a perforated punch plate with a vibrator installed on it. The thickness of the formed product from gypsum-thermowood composition is determined empirically and calculated by the volume of thermally modified wood filler in the gypsum solution.

4. The initial setting of the gypsum-thermowood composition is carried out in a pressed state. This is necessary in order to avoid the process of floating of the thermally modified wood filler and to ensure its uniform distribution along the height of the formed product. The approximate time of the initial setting of the gypsum-thermowood composition is about 10 minutes.

5. Removing (lifting) the punch plate after the gypsum-thermowood composition has begun to set, with excess set gypsum mortar on its surface.

6. The gypsum-thermowood composition is cured under natural conditions.

The density of gypsum-thermowood composite (GTWC) obtained by this method is on average 660-680 kg/ ^m3 ; strength class B1 (M15).

LIST OF REFERENCES

1. Patent 808428 SU, IPC C04B 11/09. Gypsum concrete mixture / L.P. Moseykova, L.D. Grigorieva; applicant and patent holder Krasnoyarsk branch of the State All-Union Scientific Research Institute of Building Materials and Structures named after P.P. Budnikov. – No. 2763552; declared 08.05.1979; published 28.02.1981. – 5 p.

2. Patent. 2790390 RF, IPC C04B 11/20. Method for manufacturing thermally reinforced wood concrete / V.Yu. Chernov; applicant and patent holder Limited Liability Company "New Forest Technologies" (LLC "NovLesTekh"). - No. 2021139396/03; declared. 27.12.2021; published. 17.02.2023, Bulletin No. 5. - 9 p.

Claims (1)

A method for producing a gypsum-thermowood composite comprising grinding wood raw material to a particle size in the range from 5 mm to 20 mm, drying it and thermally modifying it in a steam-air environment at processing temperatures from 160 to 200 °C, dosing the components, preparing a gypsum and water solution, characterized in that the gypsum-thermowood composite is produced by filling a sealed open-top mold with ground thermally modified wood while simultaneously adding a gypsum and water solution, compacting the resulting composite in the mold using a perforated punch plate by moving it from top to bottom while simultaneously operating a vibrator, maintaining the composite in a compressed state until the gypsum solution sets and removing the punch plate with excess solution on its upper part, the gypsum-thermowood mixture has a component ratio, vol. %: gypsum 23, water 23, filler in the form of the specified crushed thermally modified wood 54.