CS249231B1 - Mineral fibrous thermoinsulating plate with cellulose bond and method of its production - Google Patents

Abstract

The solution relates to mineral-fiber thermal insulation and that of its production. Mineral fiber thermal insulation board It consists of mineral fibers, fillers such as a] for example halloyzite, kaolin, bentonite, perlite, hydrophobic emulsion, aluminum sulfate, polyacrylamide flocculant and water-soluble derivatives cellulose. Mineral Fiber Docking Solutions can be used as insulation material for insulation building objects.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellulosic binder of a mineral-fiber-based heat-insulating thatch.

Mineral fiber and ceramic filler thermal insulation boards are currently manufactured by paper technology, with the binder forming a native or greased scratch. In the prior art, the composition consists of the following components: mineral fibers, ceramic fillers (halloyzite, kaolin, bentonite), paraffin emulsion, aluminum sulfate and a flocculating agent. An aqueous suspension of from 1 to 3% by weight of the components is prepared from these components, which is dewatered on a forming machine and the wet thatch is dried. This method of manufacture, because of the low solids content of the suspension, requires a binder of specific properties. Such a technologically preferred binder is starch. In the first phase of the process, it is retained on the solid components of the composition and, in a subsequent heat treatment, forms a binder film on the ceramic fiber skeleton. From the material point of view, the application of starch as a binder is less preferred. The disadvantage is that starch is an important food product, a raw material, has low microbiological resistance and a relatively high cost for such large-scale production as the thermal insulation board technology considered.

These disadvantages are overcome with the cellulosic binder mineral fiber insulating thatch of the present invention, which is based on a mineral fiber thermal insulating board composed of mineral fibers, ceramic fillers and additives, characterized in that it consists of 60 to 90% by weight. % of mineral fibers, 1 to 15 wt. % of ceramic fillers such as halloyzite, kaolin, bentonite, perllite, from 0.6 to 1.2 wt. % of a hydrophobizing emulsion, from 0.5 to 2 wt. aluminum sulfate, from 0.005 to 0.05% of a flocculating agent based on polyacrylamide and from 3 to 10% by weight of water-soluble cellulose derivatives, preferably carboxymethylcellulose or hydroxymethylcellulose. The binder, a soluble cellulose derivative, is introduced into the suspension system in powder form in an air stream prior to dewatering, and subsequently the suspension is dewatered prior to dissolution of the cellulose derivative.

The present invention is based on the application of a binder of water-soluble cellulose derivatives in such a way that their dissolution takes place largely in the formation in the wet plate. The dissolution of the cellulose derivative takes place in the wet plate during its transport to the dryer and especially in the first part of the dryer, where the material is not dried but only heated as a result of the steam supply.

The material coming out of the forming machine contains about 50 wt. water. Dissolution of the cellulose derivative in this amount of water produces a relatively concentrated colloidal solution; according to the content of cellulose derivative in the dry matter, it is a concentration of 3 to 10% by weight. An advantage of the application of the cellulose binder according to the invention is also the binder property of said concentration. In this state, the binder achieves a semi-solid gel consistency which causes good cohesion of the composite components. The material shows a certain wet strength, so there are no problems with its transport to the dryer.

The cellulose derivatives are introduced into the slurry, which contains all the other ingredients, on the forming machine in the region of the slurry inflow into the machine. Under these conditions, the cellulose derivatives are in short contact with the excess water, only up to 30 seconds. During this time, s-a will not dissolve in the system. Subsequently, the suspension is dewatered and the cellulose derivative particles are collected in a wet plate. In a further process of the wet d-beam in the process, they dissolve therein and thereby form the binder of the material. If the binder were introduced earlier, it would dissolve in a large excess of water and, in the case of dewatering, it would enter the undersized water, thus not fulfilling its function.

The main advantage of the invention is that it uses a binder which is approximately half cheaper than starch and is not a food raw material for the production of heat insulating boards.

The technological procedure for the production of insulation boards is simple. The only difference from the existing technology is that the binder, cellulose derivatives, is introduced into the system on the forming machine. The cellulose derivatives in powder form are introduced into the suspension by a stream of air by means of a jet pump device.

In doing so, the individual binder particles flow into the suspension, preventing the formation of agglomerates, agglomerates, which would be difficult to disperse.

In addition to introducing the binder into the system, the technological process for preparing the insulating boards is conventional: from these components an aqueous suspension is prepared which contains 1 to 3% by weight of the composition. solids.

The suspension can be prepared in two ways:

(a) the individual components are gradually added to the suspension in the order of fibers, ceramic fillers, aluminum sulphate (pH - 4,5), flocculating agent and cellulose derivatives;

b) separately preparing two suspensions which are mixed together [(fibers), (clays and a hydrophobising emulsion)], then aluminum sulphate, flocculating agent and cellulose derivatives are added.

The suspension is suction filtered, compressed and dried at 120-150 ° C. Water vapor is injected into the first part of the dryer to completely dissolve the cellulose derivative in the wet plate.

Examples

1. Composition of the mineral-fiber heat-insulating thatched prepared according to the invention (expressed in% by weight of that-dry matter):

mineral fiber 79.7 kaolin 7.0 bentonite 3.0 paraffin emulsion 0.8 'aluminum sulphate 1.5 flocculating agent 0.007 carboxymethylcellulose 8.0

An aqueous suspension of 2% by weight is prepared from the above ingredients, with the abundance and order of dosing of the above ingredients. Carboxymethylcellulose is introduced into the suspension on a molding machine by an air injector.

The suspension is dewatered on a forming machine and stamped. Dry at 130 ° C. In the first part of the dryer, the insulating boards are heated with steam to obtain the desired binder properties.

Mineral fiber insulating thatched properties:

density 340 kg. m ^-3 flexural strength 2.8 MPa

2. Composition of the mineral-fiber-based insulating thatched compound (wt.% In dry matter) prepared according to the invention:

mineral fiber 89.2 kaolin 1.0 bentonite 0.5 paraffinic emulsion 0.8 aluminum sulphate 1.5 flocculating agent 0,007 carboxymethylcellulose 7.0

2% by weight of the above ingredients is prepared. an aqueous suspension in the same manner as in Example 1. Carboxymethylcellulose is introduced into the suspension on a forming machine by an air injector. The suspension is dewatered on a forming machine and press-formed. The wet thatch is heated with steam and the first part of the oven and then dried at 140 ° C.

Properties of mineral fiber thermal insulation

density 240 kg. m ~ ³ bending strength of 2.2 MPa

3. Composition of the mineral-fiber heat-insulating thatched prepared according to the invention (expressed in% by weight on that-dry matter):

mineral fiber 91.2 kaolin 1.0 bentonite 0.5 paraffinic emulsion 0.8 aluminum sulfate 1.5 flocculating agent 0.007 hydroxymethylcellulose 5

2% w / w of the above components was prepared. an aqueous suspension in the same manner as in Example 1. Hydroxymethylcellulose is introduced into the suspension on a molding machine by an air injector. The suspension is dewatered on a forming machine and press-formed. The wet thatch is heated with steam in the first part of the oven and then dried at 130 ° C.

Properties of mineral fiber thermal insulation

density 220 kg. m ~ ³ flexural strength 1.9 MPa

Claims (2)

CLAIMS 1. Mineral fiber cellulosic binder thermal insulation board composed of mineral fibers, ceramic fillers and additives, characterized in that it consists of 60 to 90 wt. % of mineral fibers, 1 to 15 wt. % of ceramic fillers such as halloyzite, kaolin, bentonite, perlite; % of a hydrophobizing paraffinic emulsion of 0.5 to 2 wt. % of aluminum sulfate, from 0.005 to 0.05 wt. % flocculating agent based on polyacrylamides and from 3 to 10 wt. water-soluble cellulose derivatives. We claim: 2. A method of producing a mineral fiber heat-insulating thatched sheet according to step 1, comprising preparing suspensions, dewatering, compacting and drying, characterized in that the binder, which is a water-soluble cellulose derivative, is introduced into the suspension system in powder form. dewatering the suspension prior to dissolving the cellulose derivative.