INORGANIC COMPOSITE BUILDING PANEL

Field of the Invention

[0001] The present invention relates to building panels. More specifically, the presently described technology relates to an inorganic composite building panel and method and system for manufacturing thereof.

Background of the Invention

[0002] Cements formed of magnesium phosphate are used in many applications. For example, magnesium phosphate cements have been used as patching materials for roads. In addition, magnesium phosphate cements are also used in dental applications, such as in crowns for teeth. However, magnesium phosphate cements currently used are created in a chemical reaction that is highly exothermic. The reaction occurs at a very high reaction rate. Therefore, it is currently difficult to create large batches of magnesium phosphate cements.

[0003] As it is difficult to create large amounts of these cements, it is also difficult to use the cements in applications where a large amount of the cements are required. For example, in the construction industry, it is currently difficult, if not impossible, to use current systems and methods for creating building panels (such as panels for the outside walls of buildings, floor panels, and roof panels) made of magnesium phosphate cements.

[0004] In addition, current magnesium phosphate cements exhibit large compressive strengths, but typically weak tensile strengths. Therefore, such cements may not be useful in applications where materials experience large tensile forces. For example, building panels such as floor panels and roof panels experience a large compressive load on the top, or load-bearing side, and large

tensile forces on the opposite side of the panels. Therefore, it is difficult to fabricate floor and/or roof panels using currently available magnesium phosphate cements, as these cements may not be capable of withstanding the tensile forces typically experienced in roof and floor panels. While current cements can be used to create roof and floor panels, typically a large amount of cement must be used in order to provide sufficient tensile strength. However, with increasing the amount of cement used in these panels comes added weight to the panel and cost in producing the panel.

[0005] Current systems and methods for producing magnesium phosphate cements incorporate chopped fibers into the cement to provide for increased strength. However, these fibers tend to act as crack inhibitors and provide very little additional tensile strength to the cement.

[0006] Moreover, current fibers used in the cements do not chemically bond with the cement and leave voids between the chopped fibers and the surrounding cement. These voids can decrease the actual strength of the cement below its potential strength. In other words, while the incorporation of fibers can increase a cement's strength, the increase in strength can be increased even more if chemical bonding existed between the fibers and the cement.

[0007] Therefore, there is a need for an inorganic composite building panel. More particularly, there is a need for a low-cost inorganic composite building panel that is lightweight and exhibits improved compressive and tensile strength. Additionally, there is a need for a system and method of manufacturing an inorganic composite building panel.

Summary of the Invention

[0008] The presently described technology provides an integrated inorganic composite building panel. The building panel includes a first exterior member, a second exterior member, and a plurality of interior support members. The first and second exterior members are attached to the interior support members.

10009] The presently described technology also provides a method for manufacturing an inorganic composite building panel. The method includes providing a plurality of interior support members and attaching the plurality of interior support members to the first and second exterior members.

[0010] The presently described technology also provides a system for manufacturing an inorganic composite building panel. The system includes a first slurry applicator for applying cement to a plurality of fibers to produce a first exterior member, a second exterior member, and a plurality of interior support members, and an assembly unit for bonding the plurality of interior support members to said first and second exterior members.

Brief Description of the Drawings

[0011] Figure 1 illustrates a cross-sectional view of a chemically and/or mechanically bonded inorganic composite, according to at least one embodiment of the presently described technology.

[0012] Figure 2 illustrates a flow diagram of a method for manufacturing a chemically and/or mechanically bonded inorganic composite, according to at least one embodiment of the presently described technology.

[0013] Figure 3 illustrates a system for manufacturing a chemically and/or mechanically bonded inorganic composite, according to at least one embodiment of the presently described technology.

[0014] Figure 4 illustrates a cross-sectional view of a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology.

[0015] Figure 5 illustrates a flow diagram of a method for manufacturing a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology.

[0016] Figure 6 illustrates a system for manufacturing a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology.

[0017] Figure 7 illustrates an isometric view of a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology.

[0018] Figure 8 illustrates a plan view of a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology.

[0019] Figure 9 illustrates an isometric view of an interior support member, according to at least one embodiment of the presently described technology.

Detailed Description of Preferred Embodimentf s}

[0020] Figure 1 illustrates a cross-sectional view of a chemically and/or mechanically bonded inorganic composite 100, according to at least one

embodiment of the presently described technology. The composite 100 includes cement 110 and a plurality of fibers 120.

[0021] The cement 110 can encapsulate the fibers 120. In addition, the cement 110 can be attached to the fiber 120. More particularly, the cement 110 can be chemically and/or mechanically bonded to the fibers 110. Alternatively, the cement 110 can encapsulate only a portion of the fibers 120. The unencapsulated fibers 120 can be attached or chemically and/or mechanically bonded to other inorganic composites 100, as described below.

[0022] The cement 110 can include phosphate, water, metal oxide, and filler. The phosphate can include potassium phosphate (KH ₂ PO ₄ ) and/or ammonium phosphate, for example. The metal oxide can include one or more of magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), titanium oxide (TiO ₂ ), iron oxide (Fe ₂ Os), calcium oxide (CaO), and/or copper oxide (CuO or Cu ₂ O), for example. The filler can include C fly ash, boron carbide, sand, calcium silicate, or wollastonite (CaSiO ₃ ), for example.

[0023] The fibers 120 can include basalt, glass, ceramic, metal, carbon, and/or aramid fibers, for example. The fibers 120 can be continuous or longer than a dimension of an object or structure to be formed with the composite 100. Additionally, continuous fibers can be formed into various shapes, such as a mat. Alternatively, the fibers 120 can be non-continuous or shorter than a dimension of an object or structure to be formed with the composite 100. Non-continuous fibers can include chopped fibers, for example.

[0024] Figure 2 illustrates a flowchart of a method 200 for manufacturing a chemically and/or mechanically bonded inorganic composite, such as the chemically and/or mechanically bonded inorganic composite 100 of Figure 1, according to at least one embodiment of the presently described technology. The

method 200 includes mixing phosphate with water to form a solution 210, mixing metal oxide and filler with the solution to form a slurry 220, adding fibers to the slurry 230, and curing the slurry and fiber combination to form a composite 240.

[0025] At step 210, phosphate, such as potassium phosphate (KH ₂ PO ₄ ) and/or ammonium phosphate, can be mixed with water (H ₂ O) to form a solution. More particularly, the KH ₂ PO ₄ can be mixed with H ₂ O in a high shear mixture for about 5 to 20 minutes, for example.

[0026] At step 220, metal oxide, such as magnesium oxide (MgO), aluminum oxide (Al ₂ O ₃ ), calcium oxide (CaO), titanium oxide (TiO ₂ ), iron oxide (Fe ₂ O ₃ ), and/or copper oxide (CuO or Cu ₂ O), and filler, such as C fly ash, boron carbide, sand, calcium silicate, and/or wollastonite (CaSiO ₃ ), can be mixed with the solution to form a cement slurry. More particularly, MgO and C fly ash can be mixed with the KH ₂ PO4 solution in a high shear mixture for about 8 minutes or until a flowable slurry forms, for example.

[0027] At step 230, fibers, such as basalt, glass, ceramic, metal, carbon, and/or aramid fibers, can be added to the slurry. More particularly, fibers can be added to the slurry in a batch process. For example, basalt fibers can be placed into a mold. Next, the slurry can be poured into the mold and over the basalt fibers. Alternatively, fibers can be added to the slurry in a continuous process. For example, a basalt fiber mat can be transported by a conveyor. Then, the slurry can be poured over the basalt fiber mat. Next, the slurry can be impregnated into the fiber mat by applying compressive force. For example, the slurry and fiber mat can pass between a plurality of rollers that apply compressive force to the slurry and mat, as described below.

[0028] In at least one embodiment of the presently described technology, a wetting agent can be applied to the fibers to decrease the surface tension of fibers prior to introduction into the slurry, as described below.

[0029] At step 240, the slurry and fiber combination can be set or cured to form a chemically and/or mechanically bonded inorganic composite, such as the chemically and/or mechanically bonded inorganic composite 100 of Figure 1. For example, the slurry can cure or set in air. Alternatively, for example, the slurry can cure or set in water. Additionally, for example, the slurry can cure or set at room temperature. Alternatively, for example, the slurry can cure or set at an elevated temperature. An elevated temperature can include temperatures above room temperature. For example, an elevated temperature can include about 86 degrees Fahrenheit to about 110 degrees Fahrenheit.

[0030] In at least one embodiment of the presently described technology, one or more curing agents can be added to the ceramic composite before and/or during curing. For example, one or more of phosphoric acid, a phosphate (such as monopotassium phosphate) and a water soluble metal oxide (such as magnesium hydroxide) can be used.

[0031] In at least one embodiment of the presently described technology, one or more of the steps 210-240 can be performed in a vacuum, as described below.

[0032] As will be appreciated by those of skill in the art, certain steps can be performed in ways other than those recited above and the steps can be performed in sequences other than those recited above.

[0033] Figure 3 illustrates a system for manufacturing a chemically and/or mechanically bonded inorganic composite, such as the chemically and/or mechanically bonded inorganic composite 100 of Figure 1. The system 300

includes a wetting agent applicator 310, a first slurry applicator 320, a second slurry applicator 330, a plurality of rollers 340, and a conveying unit 350.

[0034] In operation, a mat of fiber moves through the system 300 on the conveying unit 350, such as a conveyor, as shown by direction arrows 360. The mat passes under the wetting agent applicator 310. The wetting agent applicator 310 continuously applies a wetting agent, such as saline, magnesium hydroxide (Mg(OH) ₂ ), potassium phosphate (K ₂ HPO ₄ ), and/or other surfactant, to the mat. The wetting agent applicator 310 can apply the wetting agent to the mat by spraying, rolling, or brushing the wetting agent onto the mat. The amount of wetting agent applied to the mat can be varied by adjusting the speed at which the mat passes under the wetting agent applicator 310 (that is, the speed of the conveying unit 350) and/or by adjusting the rate at which the wetting agent is expelled from the wetting agent applicator 310.

[0035J Next, the mat passes under the first slurry applicator 320. The first slurry applicator 320 continuously applies a ceramic concrete or cement slurry, such as the slurry described in step 220 of Figure 2, to the mat. The first slurry applicator 320 can apply the slurry to the mat by pouring, rolling, or brushing the slurry onto the mat. The amount of slurry applied to the mat can be varied by adjusting the speed at which the mat passes under the first slurry applicator 320 (that is, the speed of the conveying unit 350) and/or by adjusting the rate at which the slurry is expelled from the first slurry applicator 320.

[0036J Next, the mat passes between a plurality of rollers 340. The rollers 340 include rounded surfaces capable of applying compressive pressure to the mat and the slurry applied by the first slurry applicator 320. For example, the rollers 340 can include a non-reactive material shaped in a cylindrical form. In such an example, the rollers 340 can be utilized in a manner similar to dough rollers. For

example, a pair of rollers 340, each rotating in the opposite direction, can compress , the slurry and the mat. By applying pressure, the fibers in mat can be impregnated with the slurry.

[0037] In an embodiment of the presently described technology, one or more of the first slurry applicator 320 and the rollers 340 can be enclosed in a vacuum as the mat passes under and through. For example, the first slurry applicator 320 and/or the rollers 340 can be enclosed in a volume that includes an atmosphere with air pressure less than ambient air pressure. In such an embodiment, the vacuum surrounding the first slurry applicator 320 and/or the rollers 340 can be a partial or total vacuum. Such a vacuum can assist with removing air pockets or voids as the fibers of the mat are impregnated with the slurry.

[0038] Next, the mat, impregnated with the slurry, passes under a second slurry applicator 330. The second slurry applicator 330 continuously applies additional ceramic concrete or cement slurry, such as the slurry described in step 220 of Figure 2, to the mat. Similar to first slurry applicator 320, the second slurry applicator 330 can apply the slurry to the mat by pouring, rolling, or brushing the slurry onto the mat. The amount of slurry applied to mat can be varied by adjusting the speed at which the mat passes under the second slurry applicator 330 (that is, the speed of the conveying unit 350) and/or by adjusting the rate at which the slurry is expelled from the second slurry applicator 330.

[0039] Additional slurry can be provided by the second slurry applicator 330 to provide a uniform thickness to the mat and slurry. After passing through the rollers 340, the mat and slurry can have a non-uniform thickness and/or a non-uniform surface (that is, a rough surface). By applying additional slurry, the final composite material can possess a more uniform thickness and/or surface.

[0040] Next, the mat and slurry combination can be placed into a position of rest. In other words, the mat and slurry combination stops moving (that is, the conveying unit 350 stops moving). Once the mat and slurry combination stops moving, the ceramic concrete or cement slurry can set or cure.

[0041] In at least one embodiment of the presently described technology, an entire mat passes through. the system 300 before coming to rest to cure or set. Once the mat and slurry has set or cured, a chemically and/or mechanically bonded inorganic composite, such as the chemically and/or mechanically bonded inorganic composite 100 of Figure 1, is formed. The composite can then be cut to a desired length or shape.

[0042] In at least one embodiment of the presently described technology, the mat and slurry pass continuously through the system 300. The mat and slurry combination can be cut into a desired length or shape as it passes beyond the second slurry applicator 330. In other words, once a desired amount of the mat and slurry have passed the second slurry applicator 330, the mat can be cut. The cut portion of the mat and slurry can then be placed in a position of rest to cure or set, as described above.

[0043] In at least one embodiment of the presently described technology, the ceramic concrete or cement slurry can start to cure or set before the mat is placed in a position of rest. For example, the ceramic concrete or cement slurry can start to cure or set when expelled from the first and second slurry applicators 320, 300. Alternatively, for example, the ceramic concrete or cement slurry can start to cure or set when mixed.

[0044] Figure 4 illustrates a cross-sectional view of a chemically and/or mechanically bonded inorganic composite building panel 400, according to at least one embodiment of the presently described technology. The panel 400 includes a

First exterior member 410, a second exterior member 420, a plurality of interior support members 430, and insulation 440.

[0045] The first exterior member 410, the second exterior member 420, and the interior support members 430 may be referred to as members, elements, components or trusses. The panel 400 may be referred to as a panel or sheet. Additionally, the terms interior, exterior, top, bottom, front, and back can be interchangeable depending on the orientation and function of a particular embodiment of the presently described technology.

[0046] The first exterior member 410 can be oriented substantially parallel to the second exterior member 420. The interior support members 430 can be placed between the exterior members 410, 420. For example, the supports 430 can be oriented substantially perpendicular to the exterior members 410, 420 of the building panel 400. Alternatively, the supports 430 can be oriented at various angles to the exterior members 410, 420, for example. Additionally, the interior support members 430 can be attached to the first and second exterior members 410, 420. For example, the supports 430 can be chemically and/or mechanically bonded to the exterior members 410, 420 of the building panel 400.

[0047] The exterior members 410, 420 and supports 430 can include a chemically and/or mechanically bonded inorganic composite, such as the chemically and/or mechanically bonded inorganic composite 100 of Figure 1. However, the exterior members 410, 420 and supports 430 can include different chemically and/or mechanically bonded inorganic composites.

[0048] Any one or more of the exterior members 410, 420 and supports 430 can include a different thickness of cement and/or volume of fiber. For example, the nominal thickness of the first exterior member or top 410 can be about 0.25 inch (0.64 centimeters). The nominal thickness of the second exterior member or bottom

420 and the interior support members or trusses 430 can be about 0.25 inch (0.64 cm) to about 0.5 inch (1.27 cm), for example. Although a thinner composite can be more cost effective (that is, less material, quicker cure), a thicker composite can provide additional compressive strength. Additionally, for example, one or more of the exterior members 410, 420 and supports 430 can include a fiber volume from about 10 percent to about 40 percent. However, the fiber volume can also be larger or smaller. Although a larger fiber volume can increase the tensile strength of the composite, and thus, the component or member of the building panel, it can also result in a reduction of compressive strength.

[0049] Additionally, one or more of the exterior members 410, 420 and supports 430 can be formed differently (that is, formed by different process and under different conditions). As described above, a chemically and/or mechanically bonded inorganic composite, such as the chemically and/or mechanically bonded inorganic composite 100 of Figure 1, can be formed by casting (that is, cement poured over fiber in a mold) or impregnation (that is, rollers impregnate fiber mat with cement slurry). One or more of the elements or components of the building panel, particularly, the first and second exterior members 410, 420 and the interior support members 430, can include composites formed by either casting or impregnation. Composites formed by impregnation can be stronger than composites formed by casting because of reduced porosity (that is, better integration of cement and fiber).

[0050] Also, as described above, the composite can be formed in atmosphere or in a vacuum. Thus, one or more of the elements or components of the building panel, such as the exterior members 410, 420 and the supports 430, can include composites formed in atmosphere or in a vacuum. Composites formed in a vacuum can be stronger than composites formed in atmosphere because of reduced porosity, as described above.

[0051) The insulation 440 between the supports 430 can include air, foam, fiberglass, or cardboard, for example.

[0052] The chemically and/or mechanically bonded inorganic composite building panel 400 can be useful in a many different types of structures, such as residential- commercial, and industrial buildings. More particularly, the building panels 400 can include the wall panels, roof panels, and/or floor panels in a residential, commercial, or industrial building, for example. Furthermore, the building panels 400 can be stronger (in tension and/or compression) than conventional building panels, as well as lightweight and flame retardant and/or fire resistant.

[0053] For example, in concrete roof panels and floor panels used in buildings, the top of the panels typically experience a compressive load while the bottom of the panels typically experience a tensile load. By incorporating the composite described herein into floor and roof panels, the added tensile strength achieved by the composite allows for less total material to be used in order to achieve comparable compressive and tensile strengths. In other words, as the composite described herein is considerably stronger in tension than current concretes, a smaller amount of the composite can be used to achieve similar compressive and tensile strength requirements.

[0054] Moreover, the increased tensile strength of the composite cement can provide for lighter and cheaper building panels. For example, as the composite cement is stronger than traditional cements used in building panels, less of the composite cement can be used to replace traditional cements while still providing equal or greater tensile and/or compressive strengths. Therefore, by using less material to achieve the same or greater strength, the total weight of building panels made with the composite cement can be considerably lighter. Similarly, by using

less material to achieve the same function, the total cost of producing a building panel decreases.

(0055] Figure 7 illustrates an isometric view of a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology. Figure 8 illustrates a plan view of a chemically and/or mechanically bonded inorganic composite building panel, according to at least one embodiment of the presently described technology.

[0056] Additionally, for example, the composite material can be used as vertical support members, or trusses, in a building panel. Figure 9 illustrates an isometric view of an interior support member, according to at least one embodiment of the presently described technology. The ceramic composite can be a useful replacement for vertical support members or trusses made of steel as the composite materials do not corrode (as steel does) and have increased resistance to fire (over steel).Figure 5 illustrates a flow diagram of a method 500 for manufacturing the chemically and/or mechanically bonded inorganic composite building structure 400 of Figure 4, according to at least one embodiment of the presently described technology. The method 500 includes providing a plurality of interior support members 510, attaching the interior support members to a first exterior member 520, providing insulation between the interior support members 530, and attaching the interior support members to a second exterior member 540.

[0057] At step 510, interior support members, such as the interior support members 430 of Figure 4, are provided. For example, the supports can be prefabricated. Alternatively, for example, the supports can be manufactured in time with the other components of the building panel, such as the exterior members 410, 420 of the building panel 400 of Figure 4. As described above, the supports can include a chemically and/or mechanically bonded inorganic composite, such as the