LINING PANEL, A METHOD FOR MANUFACTURING THE SAME, AND A FIRE RETARDANT COMPOSITION FOR USE IN THE METHOD

Abstract: A fire-resistant, insulating lining panel comprised of an insulating layer (1) of mineral wool and a covering material layer (2, 3) placed on both sides of said insulating layer. Onto the mineral wool layer (1) acting as the insulation is first applied a reinforcing fabric (2), after which onto the reinforcing fabric (2) and the insulation (1) is applied a layer of a fire-resistant binding compound (3) containing magnesium chloride in an amount sufficient for making said binding compound noncombustible after setting.

Description: LINING PANEL, A METHOD FOR MANUFACTURING THE SAME, AND A FIRE RETARDANT COMPOSITION FOR USE IN THE METHOD The present invention relates to a fire-resistant lining panel according to the preamble of claim 1 , said panel being comprised of mineral wool and a facing material . The invention also concerns a method according to the preamble of claim 6 for manufacturing such a lining panel. The invention further concerns a fire retardant composition according to the preamble of claim 8. Housing and shipbuilding have a need for a lightweight and low-cost, fire- resistant insulation material which also readily accepts a coating system. Due to their easy handling, lining materials in sheet/board/panel form are preferred. However, conventional materials are hampered by inferior recyclability and presence of toxic emissions during their manufacture and under fire. For shipbuilding use. fire-resistant structures are usually made from thin sheet steel, behind which or inside a cladding cassette made thereof is adhered a sheet of mineral wool or other noncombustible material acting as a fire-resistant and heat- insulating layer. A problem with sheet-steel-clad structures has been their high weight and limited possibilities of altering the look of the wall. For instance, the joints between the installed panels remain visible in a disturbing manner. Steel panel structures are also relatively costly and difficult to manufacture, making them suited only for use in locations not critical to material costs. Special tooling is required for the manufacture and fabrication of current cladding materials and sheet steel panel structures. Hence, fabricated insulation materials developed for shipbuilding are not used for conventional building constructions, where reduced fire-resistance requirements apply and no extra costs to building investments are desirable. However, much improved fire safety of buildings could be achieved, provided that a cost-advantageous and easy-to-use fire-resistant mateπal were available It is an object of the present invention to provide a fire-resistant insulation material featuring easy handling and capable of accepting a desired coating system after installation The goal of the invention is achieved by placing first a backing fabric on the mineral wool sheet and then applying on the backing fabric a fire-resistant binding material containing magnesium chloride in a sufficient amount to make the binding material fire-resistant after setting The required amount of magnesium chloπde in the fire-resistant mateπal is at least 37 wt-% , advantageously at least 47 wt-% More specifically, the lining panel according to the invention is characterized by what is stated in the characterizing part of claim 1 Furthermore, the method according to the invention is characterized by what is stated in the characterizing part of claim 6 The fire retardant composition according to the invention is characterized by what is stated in the characterizing part of claim 8 The invention provides significant benefits The lining panel according to the invention forms smooth and continuous planar surfaces without seams, whereby the panel offers good insulation properties against heat, cold, sound and fire The specific density of the panel is low, making it suitable for use in locations critical to the mass of the insulation such as fast-going ships, airplanes and containers used in, e g , road transport of goods and materials The surface of the material can be easily patterned to give an eye- pleasing look to the installed sheet The sheet is easy to install due to its stiffness, whereby supplementary support structures are redundant. To attain a sufficient high fire rating, the panel can be made from a number of insulating layers, and for improved stiffness, the panel may be formed to exhibit a honeycomb structure. The panel has sufficient stiffness for erection of self-supporting space constructions. Under fire, the sheet releases no toxic gases and its basic components are recyclable. The panel can be manufactured to a standard size, or alternatively, it may be made into modular sizes of predetermined dimensions, whereby the panel need not be trimmed during installation. The panel can be coated during manufacture with any conventional coating material, whereby the fire-resistant binding material acts as an adhesive. After manufacture, the panel can be coated in the same manner as any conventional covering material. The sheet also makes it possible to provide a water-tight joint between an erected wall and the tloor. In the following, the invention will be examined in more detail with the help of the attached drawings. Figure 1 shows an insulation panel according to the invention comprised of a single insulating layer; Figure 2 shows an insulation panel according to the invention comprised of two insulating layers; Figure 3 illustrates a wet space floor implemented using an insulation panel according to the invention; and Figure 4 illustrates the joint between the floor of Fig. 3 and a wall. In its simplest embodiment, the lining panel according to the invention comprises a single layer of insulation 1. Over the insulation layer is placed a reinforcing backing fabπc 2 and a layer of a fire-resistant binding material 3 The insulation layer 1 is advantageously divided into pieces, and binding material is applied to the joints between the pieces, whereby the panel is provided with a number ot transverse intermediate walls 4 that stiffen the insulating panel structure Referring to Fig 1 , the strucmre shown therein is manufactured by first spreading in a mould or simply on a flat surface a binding mateπal layer on which a re¬ inforcing fabπc is placed, next applying another layer of the binding material and the reinforcing fabric In this manner, a sufficient number of layers are laminated atop another in order to achieve a sufficient stiffness Onto the exterior layer 2. 3 which is comprised of the alternating layers of the reinforcing fabπc and the binding mateπal, is placed an insulation layer 1 , advantageously of mineral wool The fibers of the wool may be aligned orthogonally or parallel to the plane of the panel, whereby the panel properties may be modified through varying the wool alignment in this manner While an orthogonal orientation of the wool fibers renders the panel of a higher compressive strength, it on the other hand requires the assembly of the insulation layer to be made from thinner wool blocks When assembling the panel from a number of blocks, the joints between the blocks are filled with the binding material Thus, these binder-filled joints are made mto compressive-strength-improving mtermediate walls 4, whose contribution to tiie compressive strength of the panel is the greater the smaller the size of the wool blocks If the insulation layer of the panel is made from a single sheet of wool, the compressive strength of the panel equals the compressive strength of the sheet itself After the first wool layer 1 is placed over the first exterior layer 2, 3, the second exterior layer is made by laminating layers of reinforcing fabπc over the insulation layer using the binding material as an adhesive Thus, the stiffness of the panel and its strength against point loads may be varied by altering the thick ness and composition of the exterior layer, and the laying of the exterior layer can be implemented using conventional laminating techniques of composite structures, whereby the exterior layers of the panel may have different compositions. After both exterior layers of the panel are laminated, the panel is cured in a heated press at about 60 - 80 °C for about 15 minutes, whereby a stiff panel results. The fire resistance of the lining panel according to the invention is based on a special binding material, while its stiffness and durability are due to the composite structure formed by the binding material and the reinforcing fabric. After setting, the fire-resistant binding material is rather brittle requiring support by a reinforcing fabric to prevent cracking of the binding material under transport or installation. While the composition of the binding material compound may vary, its fire-resistant properties are chiefly based on those of magnesium chloride. Other components of the binding compound are magnesium sulfate, sodium silicate, magnesium oxide, titanium oxide, aluminium hydroxide, and water. Titanium oxide and aluminium oxide are admixtures serving to improve the fire resistance of the compound and give it higher strength after setting. A further function of titanium oxide is to speed the drying of the composition after setting. The following formula has been found to have advantageous properties: water 135 g sodium silicate 120 g magnesium sulfate 1000 g magnesium chloride 2500 g magnesium oxide 5000 g aluminium hydroxide 800 g titanium oxide 800 g The total batch mass according to the above formula is 10355 g, of which the proportion of magnesium oxide is 48.3 % . The fire resistance of the mixture is based on the high amount of magnesium oxide. Magnesium sulfate and chloride make the compound hard and improve its fire resistance, while sodium silicate acts as a binder. Titanium oxide and aluminium hydroxide can be omitted from the formula, since they act as quality-improving admixtures only If these admixtures are omitted, the amount of magnesium oxide in the formula rises to 57 1 % Obviously, the proportions of the components in the above formula may be varied When expressed as mass percentages, the proportions of the components in the above formula are as follows water 1.3 % sodium silicate 1 2 % magnesium sulfate 9 7 % magnesium chloride 24.1 % magnesium oxide 48 3 % aluminium hydroxide 7 7 % titanium oxide 7-7 g In principle, the amount of each component may be varied by about 20 % from the nominal value of the formula Accordingly, the amount of magnesium chloπde in the formula could be in the range 2000 - 3000 g The most important component of the formula is magnesium chloride, whose amount must be sufficiently high to obtain good fire resistance Herein, the term fire resistance refers to the fire rating given by a test passed by an insulating panel designed to meet the requirements of the test, whereby the fire rating of a panel may be varied according to the needs of the intended application However, the amount of magnesium chloride should not fall below the above stated mimmum value of 37 - 38 % , and good fire resistance will not be attained until its amount is greater than 47 % The binding material/fire retardant descπbed herein is suited in particular for a lining panel manufactured implementing cold pressing techniques The invention also provides for another kind of fire retardant/bmdmg agent According to this alternative embodiment, a composition is produced which in addition to magnesium chloride and sodium silicate also contains a reaction product of the sodium silicate and an acid The composition is particularly well suited for hot pressing techniques but can also be used where cold pressing techniques are implemented The fire retardant composition according to the alternative embodiment is achieved by separately producing a reaction product of sodium silicate and acid and an aqueous solution of magnesium chloride and by combining the reaction product with the aqueous solution in order to obtain a mouldable and ductile composition The reaction product of sodium silicate and acid is obtained by first admixing the sodium silicate with water and by then reacting it with an inorganic or organic acid The amount of water is usually roughly equal to the amount of sodium silicate I e with 100 parts by weight of sodium silicate, 50 to 150 parts by weight of water are used Of the inorgamc acids used in the reaction boric acid. phosphoric acid, hydrochloric acid, and sulphuric acid may be named The orgamc acids comprise formic acid, acetic acid, oxalic acid, tartaric acid, and citric acid The molar ratio SιO /Na,0 is advantageously about 1 to 3 5, preferably about 2 to 3 3 The relative amounts of sodium silicate and acid depend on the silicon dioxide/sodium oxide ratio of the sodium silicate as well as on the acid used Generally speaking, about 1 to 100 parts by weight of (100 %) acid are used for 100 parts by weight of sodium silicate The obtained reaction product which contains at least some precipitated silicon compounds is at wish complemented by adding magnesium sulfate which like magnesium chloride hardens the completed composition When added to the reaction product, magnesium sulfate increases the viscosity of the composition. Magnesium sulfate is advantageously added in an amount of 10 to 5000 parts by weight, preferably 500 to 1000 parts by weight for 100 parts by weight of sodium silicate. The magnesium chloride is first dissolved in water, whereby 10 to 1000, preferably 50 to 200 parts by weight of magnesium chloride are dissolved into 100 parts by weight of water. In order to enhance the dissolution of the magnesium chloride, the temperamre of the water can be kept at a higher value than room temperamre, e.g. at about 30 to 90 °C, preferably about 40 to 80 °C. After the dissolution of the magnesium chloride, magnesium oxide can be added into the aqueous solution. For 100 parts by weight of magnesium chloride, 10 to 1000 parts by weight of magnesium oxide are used, advantageously 100 to 500 parts by weight, preferably 150 to 250 parts by weight. As is well known, magnesium oxide is not easily soluble in water, wherefore the addition of this component results in a fluid. Next, the sodium silicate and magnesium chloride compositions can be combined. The sodium silicate composition is advantageously added into the magnesium chloride composition under vigorous stirring. A viscous, processible composition is obtained. The composition contains about 10 to 10000 parts by weight, advantageously about 100 to 5000 parts by weight, and preferably about 500 to 3000 parts by weight of magnesium chloride for 100 parts by weight of sodium silicate. The composition contains about 100 to 10000 parts by weight, advantageously about 200 to 2000 parts by weight, and preferably about 500 to 1500 parts by weight of water for 100 parts by weight of sodium silicate. Titanium oxide can be added to the composition in order to improve its strength properties; furthermore, metal oxides generally used in fire retardant compositions, such as aluminium hydroxide, can be admixed. The dry matter in the fire retardant composition prepared in accordance with the invention typically contains 0.1 to 10 % by weight of sodium silicate and acid and a reaction product thereof, - 1 to 25 % by weight of magnesium sulfate. 10 to 60 % by weight of magnesium chloride, and 10 to 60 % by weight of magnesium oxide. In addition, the composition may contain about 0.1 to 10 % by weight of aluminium hydroxide and/or, correspondingly, titanium dioxide. Now referring to Fig. 2, a panel strucmre is shown comprised of two layers of insulating material and three layers of reinforcing fabric 2 laid with the binding compound. Such a multilayer strucmre results in a panei of higher stiffness and durability than is achievable by a single-layer strucmre, and in practice, the multilayer strucmre is preferred in applications requiring a substantial thickness of the insulating material. If a single sheet of thick insulating material were used herein, the strength of the panel would be essentially reduced, whereby supporting the panel to the underlying strucmre to be covered with the help of, e.g. , penetrating fixing means might become necessary. By contrast, the multilayer strucmre manufactured according to the invention is sufficiently stiff for use even as a self-supporting wall. In such a strucmre, it is advantageous that the compressive-strength-improving intermediate walls 4 are misaligned to avoid their coincidence. The invention provides easy insulation in special applications. In the diagram is shown one such example in which the floor and wall insulation of a wet space are implemented using a lining panel according to the invention. The floor is made from a cladding panel having the insulation layer 1 contoured slanted to provide the slope required by the floor construction, and at the lowest point of the slope, a drain 5 is located. The slanted floor panel can be manufactured by way of lamination in the same manner as a planar wall panel, whereby the dram 5 and its conduit feedthroughs are attached to the panel by means of the binding compound Referring to Fig 3, a structural arrangement is shown for a water-tight corner joint between the floor and a wall In this strucmre, the floor panel edge is provided with a steel angle 6 whose one side is bonded under the panel and the other side is extended in plane of the floor panel edge slightly above the floor top level Thus, the angle 6 protects the insulation at the edge of the floor panel and stiffens the joint. The floor panel top surface is coated with a contmuous tile covering comprised of a backing material with ceramic tiles 9 laid thereon Such a tile covering 8 is commercially available as a standard-size plate, or alternatively, cut to size according to the site to be floored The tile covering 8 may be adhered on the floor panel already during the manufacture of the floor panel The panel forming the wall of the wet space is fixed onto the steel angle 6, and the lower edge of the wall panel is supported stiffly to the steel angle 6 by means of a protective angled steel section 7 passing over the edge of the wall panel and extending over its lower edge up to the steel angle 6 The steel angle 6 and the protective steel section 7 form a stiff support strucmre fixing the floor and the wall in place In the interior of the wet space, the wall panel is covered at least around the lower edge of the wall with a prefabricated tile row 8 placed such that the lower edge of the tiles 8 rests on the tiles 8 of the floor covering In this fashion, a water-tight wall-to-floor corner joint is easily accomplished The panel according to the invention has a plurality of applications For instance, it provides for the manufacture of prefabricated door panels for shipbuilding and housing, walls and floors in general, and covering thereof, and design of various manhole covers Furthermore, the panel is suited for making co cal window framings, opemngs and feedthroughs as well as construction of wet spaces such as bathrooms The invention also makes it possible to manufacture noncombustible strucmral insulation panels for the interiors of aircraft and trains as well as for the insulation of ship interior spaces against heat, sound, cold and fire Besides those descπbed above, the present invention may have alternative embodiments The reinforcing backing fabπc may be selected from the group of woven cloths or chopped-fiber felts, and within the scope of the invention, it is also feasible in some applications to blend the binding compound with reinforcing elements such as chopped fiber, whereby the reinforcing element and the binding compound may be applied in blended form during the manufacmre of the panel In principle, the exterior surface layer or the backing layer of the panel may be made using any reinforcing elements and techniques of fabrication that are conventionally employed in the manufacmre of composite structures However, glass fiber is the most cost-advantageous choice as a reinforcing material due to its low price and advantageous properties After manufacmre, the panel edges can be provided with metallic protective stπps attached thereto

Claims: Claims: 1. A fire-resistant lining panel comprising - at least one insulating layer (1) of mineral wool, and - an exterior layer (2, 3) on both sides of said insulating layer, characterized in that said exterior layer is comprised of - a binding material (3) containing magnesium chloride in an amount sufficient for rendering said binding material compound noncombustible, and - at least one reinforcing component (2). 2. A lining panel as defined in claim 1, characterized in that said reinforcing element is a fabric (2) and at least two layers of said fabrics are laminated together with the help of said binding material to form said exterior surface layer. 3. A lining panel as defmed in ciaim 1, characterized in that said insulating layer (1) is comprised of blocks and the interblock seam joints are ad¬ hered with the help of said binding material which forms intermediate walls (4) spanned between said exterior layers (2, 3). 4. A lining panel as defined in any of the foregoing claims, character¬ ized in that the number of said insulating layers (1) is at least two. 5. A lining panel as defined in any of the foregoing claims, character¬ ized by a protective strip attached to at least one of the edges of said panel. 6. A method of manufacmring a lining panel, in which method at least the following steps are carried out: - a first exterior layer (2, 3) is laid, - onto the first exterior layer (2, 3) is placed an insulating (1) layer of mineral wool, and - onto said insulating layer (1) is laid a second exterior layer, characterized in that - a binding material compound is prepared containing magnesium chloride in a sufficient amount to make the compound noncombustible, and - each exterior surface is made as a composite of said binding material compound and a reinforcing material. 7. A method as defined in claim 6, characterized in that said insulating layer (1) is assembled from blocks and the interblock joints are filled with said binding material compound. 8. A fire retardant composition containing sodium silicate and magnesium compounds, characterized in that it contains magnesium chloride in a sufficient amount to render the composition noncombustible. 9. A fire retardant composition as defined in claim 8, characterized in that it contains at least magnesium chloride, magnesium sulfate, sodium silicate, magnesium oxide and water. 10. A fire retardant composition as defined in claim 8 or 9, a lining panel, characterized in that said composition additionally contains at least titanium oxide and aluminium hydroxide. 11. A fire retardant composition as defined in any one of the claims 8 to 10, characterized in that said composition contains at least 37 % , advantageously at least 47 % of magnesium chloride. 12. A fire retardant composition as defined in claim 8, characterized in that the composition of said fire retardant in weight percentages is as given in the formula below, whereby the amount of each component may be varied within a tolerance of 20 % with regard to the nominal total mass of the formula: water 1.3 % sodium silicate 1.2 % magnesium sulfate 9.7 % magnesium chloride 24.1 % magnesium oxide 48.3 % aluminium hydroxide 7.7 % titanium oxide 7.7 %. B. A fire retardant composition as defined in claim 8, characterized in that it contains - a reaction product of sodium silicate and an acid, and - 10 to 10000 parts by weight of magnesium chloride for 100 parts by weight of sodium silicate. 14. A composition as defined in claim 13, characterized in that it contains 100 to 10000 parts by weight of water for 100 parts by weight of sodium silicate. 15. A composition as defined in claim 13 or 14, characterized in that it further contains magnesium oxide, magnesium sulfate, alumimum hydroxide and/or titanium oxide. 16. A composition as defmed in any one of the previous claims, charac¬ terized in that the dry matter in the composition contains 0.1 to 10 % by weight of sodium siiicate and acid and a reaction product thereof. 1 to 25 % by weight of magnesium sulfate, - 10 to 60 % by weight of magnesium chloride, 10 to 60 % by weight of magnesium oxide, and optionally 0.1 to 10 % by weight of alumimum hydroxide and/or titanium dioxide, correspondingly. 17. The use of the composition according to any one of the claims 8 to 16 as a binding agent for a fire-resistant lining panel.

Inventors: NYLANDER TIMO, NYLANDER, TIMO
Applicants: FIRMO LTD OY, NYLANDER TIMO, NYLANDER, TIMO, OY FIRMO LTD.
Application year: 1996
Main classification: E04B1
IPC codes: E04B1