LV14850B - Compositions on the basis of inorganic materials and fibres of different materials and use thereof for protection of wooden panels being subjected to fire - Google Patents

Description

Description of the Invention

The invention relates to the building industry, in particular to compositions and methods for protecting wood wall panels against fire. It is proposed to provide fire protection of wood panels by using coatings made of inorganic composite material, the lint forming on the surface (s) of the wood panel. A composite panel shall consist of at least two layers: a middle layer of wood and an outer layer of at least one of non-combustible mineral materials which may in turn be composed of several layers (layers) and may contain fibers.

1. Analysis of Prior Art

Techniques for protecting various structures from high temperature exposure by non-combustible or non-flammable material with additional insulation from the protected structure with a heat-insulating interlayer are well known. Cladding boards, which are fixed in accordance with the nature and construction of the substrate and the specific conditions of the room, are widely used as heat insulation materials in construction.

It is well-known that dry plaster protects wood structures against rapid fire to a greater or lesser extent. The analogous function is also fulfilled by various finishing and cladding boards, which not only serve as heat and sound insulation boards, but also increase the fire resistance of the structure:

- polystyrene foam and polyurethane foam panels;

- cladding slabs of a mixture of perlite, cement and lime, to which are also added glass or basalt mineral fibers to increase fire resistance;

- slabs of lignopore combined from polystyrene foam, wood wool and cement;

- Heraclite building boards of wood wool and cement;

- sawdust, manufactured by pressing dried and sorted sawdust and the addition of synthetic binders;

- bark boards of crushed coniferous bark, pressed with organic matter (sawdust, shavings, textile fibers, etc.);

- mineral wool slabs consisting of mineral fibers bound to formaldehyde resin;

- asbestos cement slabs made of a mixture of asbestos and cement, sometimes with added basalt fiber;

- Other facing panels containing a wide variety of inorganic components, including clays with low thermal conductivity and high fire resistance, as well as inorganic and / or organic fibers in a variety of combinations, including interlocking thermal inserts in the form of air-filled voids fibers.

Of the natural mineral materials with refractory properties of 1580-1770 ° C which can be used for the production of these finishing and heat insulating boards, special mention should be made of the refractory clay traditionally used in brick, sand cement, etc. c. for the production of refractory materials. The fire resistance of these clays is even higher than 1580 ° C. It can also be used in metallurgy, mechanical engineering, energy, etc. refractory materials used in the industry, classified into high refractory (17702000 ° C) and ultra high refractory materials (> 2000 ° C).

For sound and thermal insulation, building walls and partitions shall be made of materials of lower volume (density), of which wood materials or other lignocellulosic materials are ecologically preferable, but have the disadvantage of increased fire risk, which increases with reduced material density. Wood materials of this type are described, for example, in LV patents 13347 and 14519 and in European patent EP1913211.

The building material as defined in patent LV13347, which is based on US patent 5,738,924, is characterized by a panel structure made of different layers of anisotropic materials. Laminated wood veneer, herbaceous and / or other vegetal fiber layers with a fixed length of impregnated synthetic resin are recommended. All layers are integrated in a single multilayer design and a significant portion of the fibers in the outer layers are oriented parallel to the panel surface in the direction of load application. As a result, the outer layers work well on compression or tensile when applied in the longitudinal direction of the material. The inner layer of material has a honeycomb structure in which the walls / framework of the honeycomb elements are formed by fibers disposed at an angle of approximately 45 and 135 degrees to the outer layers and receive shear stresses.

The invention as defined in patent LV 14519 relates to wood-based multilayer construction materials with specifically oriented fibers and consists of a sheet-like material with cellular ribs of several layers of wood veneer. Veneers layers are composite with a certain structure and glued together as a layered construction material. It may also contain multilayer glued wood elements and interlayer filler with fibrous composite material, eg made by impregnating synthetic resin fibers of vegetable origin. In one embodiment of the invention, it is proposed to treat the panel surfaces with antiseptics and / or flame retardants to prevent burns, rot and insect damage, or to cover them with additional coatings of metal, plastic and the like. suitable for sheet materials.

DendroLight® (patent EP 1913211) is a lightweight cellular solid wood panel, designed as a cellular material with many voids. An important property of this material is its durability and other physico-mechanical properties that allow it to be used in load-bearing structures such as beams and furniture, making them lighter and more durable. The fire protection of DendroLight® components is problematic as the fire safety is significantly lower than that of solid wood.

The issue of the compositional composition of the raw material used for the production of the finishing boards described above is a complex one. Depending on the application, it is offered by a variety of authors in a very wide range. For example, patent LV 14480 for the manufacture of composite materials offers the use of a wide range of compositions, including compositions in percentages by weight:

- from 40 to 60% recycled polypropylene or polyethylene;

- Ground plastic-paper packaging - from 30 to 50%;

- flax or hemp, sisal;

- or mineral fibers of the group: carbon, basalt, kevlar and other similar mineral fibers, or mixtures thereof;

- or synthetic fibers with high physico-mechanical properties;

- natural, mineral or synthetic fibers of a length of 3 to 12 mm and a content of 4 to 10%;

- acetic anhydride and vinyl acetate as cellulose modifiers, from 0.2 to 0.6%;

- maleic anhydride or other anhydride of this group, as catalyst, from 0.3 to 0.5%;

formic acid, 0.3 to 0.5%;

- polyethylene or polypropylene wax, from 2 to 4%;

- dye additives - from 1 to 3%;

- various additives traditionally used in the plastics industry, such as moisture absorbers, flame retardants, antibacterial agents and binders;

- in the composition, the polymer may be replaced by biopolymers, thereby achieving the biodegradation of the material, as well as using a biodegradation catalyst such as vegetable starch in an amount of 4 to 8% by weight of the total composition;

- optionally, wood fiber or bamboo fiber, cotton shells or rice shells may be replaced by polypropylene or polyethylene or recycled textile fibers.

U.S. Pat. Nos. 8007586 B2, US 7485186 B2 and US 7789960 B2 have a decorative and functional clay plaster composition of at least two clays, one of which is swelling clay 0-5%, the other clay is kaolin or ball clay. The clay content of the plaster is up to 30%. The plaster may contain 0.1 - 5% organic fibers and 0 - 10% inorganic pigment. Limestone, marble or sand particles with a diameter of 5 to 1000 microns and a content of 5 to 75% are recommended as fillers. Add borax decahydrate, boric acid, citric acid or acetic acid 1-7%.

US 20050031843 A1, also published as EP 1633936 A1, discloses wood or polymer coated fire barrier systems or multilayer laminates comprising one or more insulating layers and / or foaming, foam, corrugated, reflective material. layers, etc., and one or more reinforcing materials in the form of fibers or sheets, which may be individual layers or included. The inorganic polymer matrix is formed by reacting an alkali metal silicate with one or more lattice builders. The modified inorganic polymer matrix is obtained from an alkali metal silicate saturated solution and a reinforcing material. The recommended curing temperature for alkali metal silicate composites is 50 - 200 ° C and pressure 200 - 250 psi with or without vacuum forming. The resulting inorganic polymer matrix can withstand temperatures of 1000 ° C and higher, depending on the formation conditions.

European patent EP 1674435 B1 discloses a method of continuous formation of clay slabs. The clay slabs thus formed contain 60 to 85% by weight of inorganic material, including 70% by weight of clay and up to 30% by weight of dehydrating excipients. The board material also contains 10 - 40% wood fibers, 0-1% hydrophobic and 0-3% organic binders

European Patent EP 1884502 B1 provides plaster mortar consisting of chopped up to 3 mm long animal feathers mixed with a binder. The binder used is lime, cement or clay that has been moistened to form a basic environment. Plastering material is applied on the outside of the wall to be insulated.

EP 2154306 A2 proposes to form a structured construction panel made of wood wool and calcium sulphate hydrate (gypsum) coated with a 1-5 mm thick inorganic coating layer with or without a slight admixture of wood wool.

2. Purpose and essence of the invention

In order to increase the fire resistance of wood panels used in building walls, partitions and ceilings in the event of fire, it is proposed to construct the panel material as a sandwich structure (see claims 6 to 8) in which a wood-based flammable middle layer comprises mineral-based non-combustible outer layers. The middle layer is made up of honeycomb wood with exposed cells. Narrow boards, moldings, plywood, oriented strand board (OSB) or other wood composite materials can be used, glued or otherwise fastened. If the surface of the middle layer is smooth, grooves or cavities about 5 - 10 mm deep and wide are formed at an angle of 60 ° to 80 ° to the surface. The recesses are arranged in bands perpendicular to the vertical axis of the panel in the application orientation. The cavity may be formed by milling, drilling or other suitable techniques. Their purpose is to secure the outer layers of wood or its material by charring it under the influence of external heat flux in the room, eg in case of fire.

The outer composite panels of the panel are made of non-combustible minerals in a thickness of 5-10 mm in combination with vegetation etc. fibers and other excipients as defined in claims 1-5. The fiber material used shall be chopped 5 to 10 mm long flax, hemp or wood fibers, straw, grass stalks, reeds, moss, needles or cuttings. Glass and carbon fibers are also usable. The material of inorganic nature is clay, refractory clay, burnt clay, ground bricks or fragments thereof, sand, ground slaked lime, slaked lime. The binder used is clay or lime. Components such as vegetable or animal proteins and carbohydrates containing from one to 10 monosaccharides or products of incomplete hydrolysis of polysaccharides may also be incorporated into the refractory outer layers. Urea and borax or boric acid may be added. The content of inorganic composite layers in terms of dry matter content is as follows: clay - 0 - 35%, raw lime - 0 - 23% or slaked lime - 0 - 30%, sand - 50 - 75%, but other components is as follows: 5-10 mm long plant fibers - 2 - 7%, urea - 0 - 1,2%, borax - 1 - 3%, protein - 0,5 1,5%, carbohydrates - 0,7 - 1, 6%, industrial liquid by-products (eg whey, protein-containing hydrolysates) replacing part of the water.

The prepared composition of the top composite layers is applied on one surface of the wood layer of the panel. This is done with equipment that provides a 10% thicker outer layer than that intended for operation. Composite layer compact at 10-15 kPa. After hardening of the first composite layer, which can be accelerated by drying at elevated temperature, the process is repeated with respect to the second surface of the panel wood. The edges of both composite layers are cut at a slope of 30 ° to the surface or exposed to a double outer layer of wood to form a seam joint when installed in a building. The recommended thickness of composite layers is 3 -10 mm. It is best to form these composite layers 4-8 mm thick.

3. Examples of use of proposed composite materials for the protection of wood cellular panels and test results for reaction to fire

The effectiveness of the fire protection of wood panels using the proposed compositions and techniques is demonstrated by the fire resistance tests of the proposed materials in the SBI facility according to EN standard EN13823. The cellular panels Dendrolight®, coated with a layer of composite material based on inorganic materials and plant fiber composites, were tested. For the reaction to fire test, samples of 100 mm thick wood cell material DendroLight® were fabricated with only one side of the composite layer applied, which is the most sensitive case in the reaction to fire test because of its enhanced effect on wood. Each sample consisted of two panels: a short wing (495 ± 5) mm χ (1500 ± 5) mm and a long wing (1000 ± 5) mm χ (1500 ± 5) mm forming a right-angled corner. The composite layer (M) of the first sample consisted of: clay 42%, sand 50%, wood chips 4%, flax fiber -1%, urea -1%, carbohydrates -1%, protein 1%. The thickness of the composite layer was 7 mm. The second sample with composite layer composition (X) contained: clay 4%, slaked lime 23%, sand 60%, wood chips 7%, hemp fiber 2%, carbohydrate 2%, protein 1%, urea - 1%. The K layer of the inorganic composite material was 10 mm thick. DendroLight® wood honeycomb samples without coatings and DendroLight® wood honeycomb samples with a 25 or 60 mm thick medium density fibreboard were used for comparison.

.table. Results of fire reaction tests

Classifications parameter Fire reaction SBI test samples Dendrolight® Dendrolight® Dendrolight® + MDF 60mm Dendrolight® + MDF 25mm Dendrolight® + M-composition 7 mm Dendrolight® + K-composition 10 mm FIGRA [W s- ¹ ] 606.6 676.4 408.7 395.5 15.8 10.7 THRioos [MJ] 44.6 52 41.6 28.7 2 1.4 SMOGRA [m ² s' ² ] 32.8 73.4 122.3 2.4 0 2.6 TSPsoos [m ² ] 57.7 84.8 39.3 35.1 20.1 38.9 LFS Are not Are not Are not Are not Are not Are not Classification Fire reactions in class D D D D B B Smoke formation subclass s2 s2 sl sl sl sl Combustible particles formation subclass dO dO dO dO dO dO

The following terms are used in the table:

FIGRA - Fire Grovvth Rat Index;

THReoos - Total Heat Release 600s;

SMOGRA - Smoke Grovvth Rat Index;

TSPeoos - Total Smoke Production 600 s;

LFS - Lateral Flame Spread;

MDF - Medium Density Fiber Board;

Class B parameters: FIGRA <120 W s' ¹ , LFS <per sample edge, THR600s <7.5 MJ;

D - Class Parameters: 250 <FIGRA <750 W s' ¹ , THR600s> 15 MJ; sl - subclass parameters: SMOGRA <30 m ² s ² , TSP6oo _s <50 m ² ; s2 - subclass parameters: SMOGRA <180 m ² s ² , TSPeoos <200 m ² ; dO - no combustible particles present for more than 10 s within 600 s.

It can be seen from the table that the panel variants tested according to the invention provide a fire reaction class of two layers higher (class B) than DendroLight® uncoated or glued 25 or 60 mm MDF (class D) for a laminated panel. Protected with an inorganic composite material, DendroLight® produces less smoke compared to unprotected material.

Claims (8)

1. Non-combustible mineral based composite material combined with fibers of different materials, characterized by: - mineral constituents from the series: clay, refractory clay, calcined clay, crushed bricks or stones, or fragments thereof, sand, crude lime, slaked lime; - Vegetable fibers from the row: flax, hemp or wood fibers, straw, grass stalks, cane, moss, needles, cuttings and / or glass and carbon fibers, 5 to 10 mm long, with: clays and ground slaked or slaked lime are used in amounts which serve as binder between the components, and the content of inorganic components, by weight, based on the dry weight of the composite, is as follows: clay 0 to 35% slaked lime 0 to 35% 23% or slaked lime 0 to 30%, sand or ground bricks or stones 50 to 75%. Composite material according to claim 1, characterized in that the plant fiber content is from 1 to 7% by dry weight of the composite. Composite material according to claim 1 or 2, characterized in that it additionally contains components such as vegetable or animal proteins and carbohydrates containing from one to 10 monosaccharides, or is a product of incomplete hydrolysis of polysaccharides to which is added urea and borax, or boric acid. Composite material according to Claim 3, characterized in that the composite layers are incorporated into the urea as an additive by weight, based on the dry weight of the composite. 0 to 1.2%, borax or boric acid 0 to 3%, protein 0.5 to 1.5% and carbohydrates 0.7 to 1.6%. Composite material according to any one of the preceding claims, characterized in that the amount of components, based on the weight of dry matter, is as follows: clay - 0 to 35%, raw lime - 0 to 23% or quenched lime - 0 to 30%, sand - 50 to 75%, the other components are as follows: Plant fibers 5 to 10 mm long 2 to 7%, urea 0 to 1.2%, borax 1 to 3%, protein 0.5 to 1, 5%, carbohydrates 0.7 to 1.6%, whereby proteins and carbohydrates may be administered as solutions in the food industry. The use of composite materials for fire protection of wood panels by providing on the outside, at least on one side, composite layers of composite material according to any one of the preceding claims, mixing the selected components vigorously and gradually adding water until a plastic mass is added. selected depending on the water content of the components. The use of composite materials according to claim 6, characterized in that the prepared composite material composition is applied to at least one of the surfaces of the prefabricated wood panel, e.g. in the form of plaster, with a coating device providing a 10% thicker outer layer. an in-use layer and compacting the composite material at 10 to 15 kPa; then, if necessary, the composite is applied to the second surface of the wood panel and compacted analogously to the first surface, and the resulting panel composite layer edges are inclined at 30 ° to the surface or exposed to a double outer layer thickness to form composite joints . Use of composite materials for fire protection of DendroLight® panels according to claim 6 or 7, characterized in that the outer composite layers are formed on one side only using the composite material composition defined in Section 3 as composition M or K and corresponding to The composition defined in claim 5, varying only the thickness of the plant fibers and composite layer used (corresponding to wood chips plus flax fibers / 7 mm /; wood chips plus hemp fibers / 10mm /) resulting in DendroLight® panels meeting fire resistance class B according to EN 13823 , smoke formation for class sl and combustion particles for class dO (see Table 1 in Section 3).