ARTICLE CONTAINING FIBERS AND MANUFACTURING METHOD TECHNICAL FIELD This invention relates to an acoustic and / or fire-resistant absorbent article, comprising a portion of natural fibers. More particularly, this invention relates to an acoustic and / or fire-resistant absorbent article, having a portion of natural fibers, and which is suitable for use in the manufacture of acoustic and / or flame retardant or combustion retardant structures, since a method to manufacture this article. BACKGROUND Glass fibers are well known for use as a component of office furniture, office dividers and other structures used in office, school, commercial and industrial environments. Glass fibers have many advantages for these applications. They are relatively inexpensive, can be processed in a variety of shapes and densities, and have good fire resistance, fire retardant or flame retardant properties. Recently, however, considerations have arisen regarding these ubiquitous uses of glass fibers. Some have expressed considerations regarding health or safety risks that may occur during the use or manufacture of glass fiber articles. There have also been considerations regarding the use of certain volatile organic compounds and adhesive systems, such as aldehyde and formaldehyde compounds in particular, which are typically involved in structures containing glass fibers. In this way, there has been an increased interest by customers in office furniture and other office products, which do not include glass fibers as a component. Agricultural fibers have gained interest as a natural, renewable resource with potential for use in a variety of manufactured products. In particular, plant fibers such as industrial hemp, kenaf, jute, henequen or sisal and flax, can be formed into nonwoven sheet products, in the form of rolls that can then be used in subsequent manufacturing processes. In some situations, fibrous plant products are preferred as natural products that do not harm the environment and require the use of volatile organic compounds. It is known to manufacture articles using fibrous plant fiber material and a thermoplastic binder, as described for example in US Pat. No. 5,709,925, which describes the use of this composition for a decorative interior trim panel for a motor vehicle. For furniture and other structures intended to be used in an office environment, it is desirable to have a Class A fire resistance rating. This means that these products have a Flame Dispersion Index of 25 or less, and a generation rate of smoke of 450 or less, as measured by the test procedures set forth in ASTM E 84 and UL 723. Agricultural fibers, however, are inherently flammable. Thus, when these agricultural fiber products are used in an office environment, the products typically include some treatment to provide adequate resistance to the flames and to meet the Class A requirements. A similar effort to produce an article resistant to fire with natural fibers, is described in the US Patent Application Publication US 2004/0028958 A1, wherein a moldable mat comprises a flame retardant or flame retardant cellulose, a fiber component and a binder component, the mat is compressed and heated to form fire resistant panels or other products which are said to be particularly Useful in the office furniture industry. SUMMARY OF THE INVENTION Thus, an object of the invention is to provide an article that can be used in the manufacture of office furniture, partitions and other structures, this article does not include glass fibers. In this wayAnother object of the invention is to provide an article that can be used in the manufacture of office furniture, partitions and other structures, this article includes fibers from fibrous plants as a component, however, it complies with the standards for a qualification of resistance to Class A fire and having convenient sound absorption properties. According to the invention, a fire-resistant or fire-resistant article comprises a fibrous mass having both a natural fiber component and a thermoplastic binder and about 5-40% by weight (based on the weight of the fibrous mass) of a first fireproof component mixed there. The fibrous mass comprises about 1-50% by weight of thermoplastic binder and about 50-99% by weight of natural fibers. In addition, the fibrous mass has a coating of a second fireproofing component of about 1-30% by weight on its outer surfaces. By proper selection of the natural fibers, the thermoplastic binder, and the first and second flame retardant components, it is possible to make an article having both flame dispersion index values and smoke generation index values that fall within the rating of Class A fire. Furthermore, the article is made free of glass fibers and free of the formaldehyde commonly used with glass fibers. In one embodiment, the fiber mass comprises about 10-50% by weight of thermoplastic binder and about 50-90% by weight of natural fibers and in other embodiments comprises about 10-30% by weight of thermoplastic binder and 70-90% by weight of natural fibers. In another embodiment, the fiber mass comprises about 5-40% by weight of the first fireproofing component and in other embodiments comprises about 5-15% by weight of the first fireproofing component. The natural fiber content of the fiber component can be constituted of a variety of fibers of fibrous plants, including fibers such as kenaf, jute, industrial hemp, henequen or sisal, flax and mixtures thereof. In some embodiments, a mixture of kenaf and industrial hemp is used. In other modalities, only kenaf is used. Natural fibers are a renewable source, and one that does not emit potentially hazardous materials into the environment. The binder of thermoplastic material is mixed with the natural fiber in sufficient quantity to bind the fibers together on the application of heat. Suitable thermoplastic binders or materials include polypropylene, polyethylene, polyesters, nylon, copolymers and mixtures thereof. The thermoplastic materials can be in the form of fibers, bi-component fibers, powders or granules. One embodiment of the method of the invention for producing a fireproof article comprises the steps of providing a fibrous mass comprising a mixture of thermoplastic material and natural fibers, dispersing a first flame retardant component in the fibrous mass, compressing, heating the fibrous mass to form a shaped article and apply the coating of a second fire-resistant component to the shaped article. The first fireproofing component can be in a powder form that is already blown through a fibrous mass or passed under reduced pressure. After the first fire retardant is dispersed through the fibrous mass, the mass is heated to a temperature above the softening temperature of the thermoplastic material, but below the temperature where the undesired thermal degradation of the natural fibers occurs, and then it is compressed. A convenient compression apparatus includes, for example, platens, clamping point rollers or flat bed laminators. The second flame retardant can be applied to the outer surfaces of the compressed mass such as in a solution or liquid medium. In one embodiment of the method, the article can be heated again to displace any water used in the liquid medium or solution. Another embodiment of the method of the invention for producing a fireproof article comprises the steps of providing a fibrous mass comprising a mixture of thermoplastic material and natural fibers, compressing and heating the fibrous mass to form a shaped article and then dispersing a first fireproofing component in the shaped article. A second fireproofing component can be applied to the shaped article after dispersion of the first fireproofing component in the shaped article. The first fireproofing component can be in a powder form that is already blown through a fibrous mass, passes under reduced or dispe pressure at the surface of the fibrous mass. Alternatively, the first fireproofing component can be applied in a solution or other liquid form. The second fireproof can be applied to the outer surfaces of the shaped article such as in a powder, foamed or liquid form. In one embodiment of the method, the article can be heated again to displace any water used in the liquid medium or solution. In an alternate method, the first fireproofing component can be dispe through the fibrous mass, the second fireproofing component can be applied to the outer surfaces of the fibrous mass and the mass can be heat-compressed to soften the thermoplastic materials, to bind the natural fibers and displacing any water used in the solution or liquid medium from the application of the second fireproofing component. Through appropriate selections of materials and processing conditions, the resulting article can be made to have a sufficiently low dispersion index and smoke generation index to meet a Class A fire rating, as well as having suitable acoustic properties. An item with a Class A fire rating may be designed if the flame spread index (FSI) is less than 25 and the smoke generation index is 450 or less. Additionally, the article is considered to have convenient acoustic properties if a structure made with the article, such as office separation panels for example, has a sound transmission class (STC = Sound Transmission Class) above 15 and / or a coefficient of noise reduction over 0.5. The article can be used in the manufacture of office dividers or separation panels, roof panels, bulletin boards and other structures that require a Class A fire rating that are used in office, school, commercial and industrial environments. DESCRIPTION OF THE DRAWINGS The present invention can be more easily understood by reference to the following drawings. FIGURE 1 is a schematic drawing of a method for producing a fire retardant article of the present invention. FIGURE 2 is a schematic drawing of an alternate method for producing a fire retardant article of the present invention.
FIGURE 3 is a schematic drawing of another alternate method for producing a fireproof article of the present invention. FIGURE 4 is a schematic drawing of an alternative alternate method for producing a fireproof article of the present invention. FIGURE 5 is a schematic drawing of yet another alternate method for producing a fire retardant article of the present invention. DETAILED DESCRIPTION OF THE INVENTION A fire retardant article to the present invention comprises a fiber mass having a fiber component and approximately 5-40% by weight of the first fire-retardant component therein mixed; the fiber component comprises about 1-50% by weight of thermoplastic agent and about 50-99% by weight of natural fibers, the fibrous mass has a coating of a second flame retardant component and about 1-30% by weight on its outer surfaces . Additionally, the fire retardant article has a Class A fire rating and desirable acoustic properties. The fibrous mass used in the manufacture of fire-retardant articles can be provided in the form of long sheets shipped as rolls. These rolls can be manufactured commercially to include natural fibers and thermoplastic materials to the specifications of a buyer. The natural fiber component of the fibrous mass is derived from the family of fibrous plants where the trunk of a plant has fibers and a core. The fibrous plants will be those where the fibers of the core of the trunk are easily separated. Fibrous plants particularly suitable for this purpose include kenaf, jute, industrial hemp, sisal or henequen and flax. Any of these plant materials can be used alone or in combination with each other and in various proportions. The selection of the plant materials to be used will be based on the ease of manufacture in the fibrous mass for use in the invention, cost, availability and fire resistance in the finished article based on empirical tests. In one embodiment, a mixture of kenaf and industrial hemp is used. In another modality, only kenaf is used. Further, while various proportions of the different fibers can be employed, a fibrous mass is used in which the natural fiber component comprises kenaf and industrial hemp fibers in approximately equal proportions by weight. The thermoplastic material or component should have a softening temperature lower than a temperature that causes undesirable thermal degradation of the natural fibers. Suitable thermoplastic components can be selected from the group consisting of polypropylene, polyethylene, polyesters, nylon, copolymers and mixtures thereof. Of these, polypropylene is suitable due to its easy availability and its low cost. The thermoplastic component in the form of fibers can be easily incorporated into the fibrous mass in its initial manufacture. In one embodiment, the fibers can include bi-component fibers, wherein the fibers of a first thermoplastic material are coated or circumscribed within a second thermoplastic material having a lower softening temperature. Alternatively, the thermoplastic component can be in other forms such as powders or granules, which can be easily incorporated into the fibrous mass. Due to the inherent flammability of both the natural fibers and the thermoplastic materials used in the fibrous mass, a first fire retardant is dispersed throughout the fibrous mass. The first fireproofing component can be selected from materials such as borates, polybourates, boric acid, borax, phosphates and mixtures of these materials. Of these, sodium polyboute is suitable. The first fire retardant or flame retardant can be dispersed through the fibrous mass either before or after being compressed by any of several methods. When the first flame retardant is provided in the form of a powder having a bulk particle size of about 10-30 microns (450-800 mesh), these methods can include blowing the flame retardant powder to the inside of the sheets of the fibrous mass on one or both sides of the fibrous mass, or directing the flame retardant powder through sheets of the fibrous mass with a reduction in pressure on one side , or use a combination of blowing on one side of the sheets of fibrous dough and create a region of reduced pressure on the other side. Alternatively, the first flame retardant agent can be incorporated into the fibrous mass during its production, such as by pre-mixing with the natural fiber component, pre-mixed with the thermoplastic component, or mixed in conjunction with the natural fiber and component thermoplastic, before or during the formation of the fibrous mass. After the first flame retardant is dispersed in the fibrous mass, the fibrous mass is then heated to a temperature above the softening temperature of the thermoplastic component, to allow the thermoplastic material to soften and bind the natural fibers of the mass. The heated mass is compressed to a desired thickness and then optionally cooled for a period of time while in the compressed state, such that the dough retains the desired thickness and achieves the desired stiffness. A second flame retardant agent is applied as a coating to the outer surfaces of the fibrous mass. Sodium silicate was found that is well suited for this purpose. In one embodiment, the second flame retardant agent is presented in a solution of liquid medium either as a solution, a suspension or a mixture. This composition can be applied to the surfaces of the compressed fibrous mass, by techniques such as spraying, brushing, roller coating, curtain coating, foaming and immersion coating. In one embodiment, the coating is applied by spraying an aqueous solution, including at least 40% by weight sodium silicate. The coating is then allowed to dry, optionally with heating to displace the water from the aqueous solution so as to cure the coating. The fire resistant or flame retardant article of the present invention has a Class A fire rating. Specifically, the fire retardant article when incorporated into a complete structural panel including conventional cover materials, additional adhesives and optionally spacer materials in a laminated construction, has a flame dispersion index (FSI = Fíame Spread Index) of less than 25 or 25 and a smoke generation index of less than 450 or 0 to 450. More particularly, the fire retardant article of the present invention in some embodiments has an FSI of 0 to 15 and a smoke generation index of 0 to 100. Additionally, the fire retardant article has desirable acoustic properties. The noise reduction coefficient (NRC = Noise Reduction Coefficient) as well as the sound transmission class (STC = Sound Transmission Class) are useful indicators of the acoustic properties of a given material. The noise reduction coefficient (NRC) is a scalar representation of a quantity of sound energy absorbed by the impact of a particular surface. In particular, it is the average of four sound absorption coefficients of the particular surface at frequencies of 250 Hz, 500 Hz, 1000 Hz, and 2000 Hz. The sound transmission class (STC) is a widely used whole-number rating that also a separation of a construction attenuates the sound carried by the air. It is used to qualify interior walls, ceilings / floors, doors, windows and exterior wall configurations. The number is derived from sound attenuation values tested at sixteen standard frequencies from 125 Hz to 4000 Hz. These transmission loss values are then plotted on a graph of sound pressure level and the resulting curve is compared to a standard reference contour. These values are adjusted to the appropriate transmission loss curve (TL = Transmission Loss), to determine the STC rating. The fire retardant article when incorporated into a complete structural panel that includes conventional roofing materials, additional adhesives and optionally spacer materials in a laminated construction, has a noise reduction coefficient (NRC) in the range of 0.35 to 0.65 and a class of sound transmission in the range of 15 to 28. In one embodiment, for example, a fibrous mass made from a 1300 gsm mat of kenaf and polypropylene was heated and compressed according to the method of the present invention to a thickness of. 635 cm (0.25 in). Powdery polyhydrate is added to the compressed mat (15-20% by weight) followed by the addition of sodium silicate (approximately 44.01 g (approximately 1.2 oz.) Of sodium silicate solids per .09 square meter (square foot) per side) . When incorporated into a structural panel, this compressed and treated mat provides a panel that has an STC of 25-26 and an NCR of 0.3-0.4. In another embodiment, a fibrous mat made from a 1300 gsm mat of kenaf and polypropylene was heated and compressed according to the method of the present invention to a thickness of 0.69 cm (0.275 in). Poliborato powder is added to the compressed mat (25-30% by weight) followed by the addition of sodium silicate (approximately 42.52 to 70.87 g (approximately 1.5-2.5 oz.) Of sodium silicate solids per .09 square meter (square foot) per side). When incorporated into a structural panel, this compressed and treated mat provides a panel having an STC of 15 and higher and an NRC of 0.05 and higher. The present invention also encompasses alternative methods for making the fire retardant article. A method of the invention comprises the steps of (a) providing a fibrous mass comprising a mixture of the thermoplastic material and natural fibers, (b) dispersing a first fire retardant component in the fibrous mass, (c) heating the fibrous mass to a temperature on the softening temperature of the thermoplastic material but below the thermal degradation temperature of the natural fibers, (d) compressing the fibrous mass to form a shaped article, (e) applying a coating and a second flame retardant component to the shaped article; and (f) drying the coating. Another method of the invention comprises the steps of (a) providing a fibrous mass comprising a mixture of the thermoplastic material and natural fibers, (b) heating the fibrous mass to a temperature above the softening temperature of the thermoplastic material, (c) compressing the fibrous mass to form a shaped article, (d) dispersing a first fire retardant component in the fibrous mass forming the shaped article, (e) applying a coating of a second flame retardant component to the shaped article; and (f) drying the coating.
A further method of the present invention comprises the step of (a) dispersing the first fire retardant component through a fibrous mass comprising a mixture of the thermoplastic material and natural fibers, (b) applying a second fire retardant component to the outer surfaces of the fibrous mass, (c) compress the mass with heat both to soften the thermoplastic materials to bind the natural fibers and to displace any water used in the solution or liquid medium of the application of the second flame retardant component. A method for producing the fire retardant article of the present invention is illustrated schematically in FIGURE 1. The fibrous mass 10 is passed through a furnace 19 where it is heated to a temperature higher than the softening temperature of the thermoplastic component. This allows to soften the thermoplastic material and bind the natural fibers. The heated mass is then passed to a calendering unit to decrease the thickness and increase the density of the fibrous mass 10. As shown in FIGURE 1, the calendering unit includes a set of three clamping point rollers 25a, 25b and 25c, to decrease the thickness and increase the density of the fibrous mass 10. Alternatively, as illustrated in FIGS. 3 and 4, the fibrous mass 10 can be passed through a press where it is pressed between two platens of press 22, 24. In alternate modes, any process that provides convenient heat and compression is adequate. The dough is kept at the thickness while it is left to cool. The fibrous sheet 10 is then transported below a spout 12 which supplies the first flame retardant agent 14, to be supplied within the fibrous mass 10. The dispersion of the first flame retardant agent 14 in the fibrous mass body 10 can be facilitated by a system of blower 16, and / or a vacuum assist 18 for removing air and flame retardant agent through a fibrous mass. The selection of whether a blower system 16, a vacuum assist 18, or both, is used may depend on the types of fibers in the fibrous mass, the type of fire retardant employed, and the density of the fibrous mass. The fibrous mass 10 is then transported to a coating application apparatus, which in the illustrated embodiment is in the form of two spray heads 32, 34, although it will be appreciated that an apparatus with a spray head can be employed if the mass 10 it is sprayed first on one side and then on the other. The spray heads 32, 34 spray both surfaces of the fibrous mass 10 with a composition 36 containing a second fire retardant material forming the coating 40 on the outer surfaces of the fibrous mass 10. The article 50 is then the compressed fibrous mass 10. with the first flame retardant agent dispersed and having a coating 40 of the second fire retardant agent. The liner 40 in article 50 is allowed to set; this last step can be facilitated by heating the article 50 with a heat source 42 to displace any liquid medium from the mixture 36, with or without assistance of vacuum or forced air. In a variation of the embodiment of the invention described above, the shaped article is passed through at least one set of additional rollers 28a-c as illustrated in FIGURE 2. During the application of the second flame retardant component in the form of a solution or spray, the liquid of the second flame retardant component can cause the natural fibers to expand on the outer surface of the shaped article. The expanded natural fibers on the exterior surface of the shaped article can extend away from the surface creating a fluff or lint-like appearance or texture. The shaped article can be passed through at least one additional roller assembly 28a-c, in order to remove any excess liquid from the shaped article and compress and smooth any extended fibers formed on the outer surface of the shaped article resulting from the application of the second flame retardant component. An alternate method for producing the fire retardant article of the present invention is illustrated schematically in FIGURE 3. A sheet 10 of a fibrous mass comprising natural fibers and a thermoplastic material, it is transported below a spout 12, which supplies the first flame-retardant agent to be supplied inside the fibrous mass. The dispersion of the first flame retardant agent 14 in the fibrous mass body 10 can be facilitated by a blower system 16, and / or vacuum assist 18 to pass air and fire retardant agent through the fibrous mass. The selection of whether a blower system 16, vacuum assist 18, or both, is used may depend on the types of fibers in the fibrous mass, the type of flame retardant employed and the density of the fibrous mass. After the first flame retardant agent is applied, the fibrous mass 10 is passed through an oven 19 where it is heated to a temperature higher than the softening temperature of the thermoplastic component. This makes it possible to soften the thermoplastic material and bind or bind the natural fibers. The heated mass is then passed to a press 20 where it is pressed between two press platens 22, 24, which decreases the thickness and increases the density of the fibrous mass 10. The mass is maintained at the thickness while it is allowed to cool. The fibrous mass 10 is then transported to a coating application apparatus, which in the illustrated embodiment is in the form of two spray heads 32, 34, although it will be appreciated that an apparatus with a spray head can be used if the mass 10 is sprayed first on one side and then on the other. The spray heads 32, 34 spray both surfaces of the fibrous mass 10 with a composition 36 containing a second fire retardant material forming a coating 40 on the outer surfaces of the fibrous mass 10. The article 50 is the compressed fibrous mass 10 with the first flame retardant agent dispersed and having a coating 40 of the second fire retardant agent. The coating 40 in article 50 is allowed to set; this last step can be facilitated by heating the article 50 with a heat source 42 to displace any liquid medium from the mixture 36, with or without assistance of vacuum or forced air. Another method for producing a fire retardant article of the present invention comprises the steps of (a) providing a fibrous mass comprising a mixture of thermoplastic material and natural fibers, (b) dispersing a first fire retardant component in the fibrous mass, (c) applying a coating of a second fire retardant component in the fibrous mass (d) heating the fibrous mass; and (e) compressing the fibrous mass to form a shaped article and allowing the compressed article to cool. In this method, the heating and compression steps may be performed separately or simultaneously. The materials that can be used in this second method are the same as those that can be used in a first method. This method is illustrated in FIGURE 4, wherein the same elements shown in FIGURE 3 are indicated by the same reference numerals. Referring first to FIGURE 4, a sheet 10 of a fibrous mass comprising natural fibers and a thermoplastic material, is transported below a spout 12 that supplies the first flame retardant agent 14 to be supplied into the fibrous mass 10. dispersion of the flame retardant agent 14 in the fibrous mass body 10, can be facilitated by a blower system 16, and / or a vacuum assist 18 to direct air and flame retardant agent through a fibrous mass. The selection of whether a blower system 16, vacuum assist 18, or both, is used may depend on the types of fibers in the fibrous mass, the type of flame retardant employed and the density of the fibrous mass. After the first flame retardant agent is applied, the fibrous mass 10 is then transported to a coating application apparatus, which in the illustrated embodiment is in the form of two spray heads 32, 34, although it will be appreciated that an apparatus with A spray head can be used if the dough 10 is first sprayed on one side and then on the other. The spray heads 32, 34, spray both surfaces of the fibrous mass 10 with a mixture 36 containing a second fire retardant material present in a liquid medium that forms a coating 40 around the fibrous mass 10. The fibrous mass 10 is then passed through. to a heating press 20 where it is pressed between two press platens 22, 24 with heat, at a temperature higher than the softening temperature of the thermoplastic component. This allows the thermoplastic material to bind to the natural fibers, while decreasing the thickness and increasing the density of the fibrous mass 10. This step can also displace the liquid medium from the coating 40. The resulting article can be used to produce a flame-retardant structure with Class A rating satisfactory. Another method for producing the fire retardant article of the present invention is illustrated schematically in FIGURE 5. In this variation of the method illustrated in FIGURE 1, a sheet 10 of a fibrous mass comprising natural fibers and a thermoplastic material is transported, below from a dispenser 10, which supplies the first flame retardant agent within the fibrous mass. The dispersion of the first flame retardant agent 14 in the fibrous mass body 10 can be facilitated by a blower system 16, and / or vacuum assist 18 to direct air and fire retardant agent through the fibrous mass as described above. After the first flame retardant agent is applied, the fibrous mass 10 is passed through an oven 19 where it is heated to a temperature higher than the softening temperature of the thermoplastic component. This makes it possible to soften the thermoplastic material and bind or bind the natural fibers. The hot mass is then passed to a set of three clamping point rollers 25a, 25b and 25c, which decrease the thickness and increase the density of the fibrous mass 10. After passing through the clamping point rollers 25a, 25b and 25c, the fibrous mass 10 is cooled and then transported to a coating application apparatus, which in the illustrated embodiment is in the form of two spray heads 32, 34, although it will be appreciated that an apparatus with other methods of applying the coating on the outer surfaces of the fibrous mass will be adequate. The spray heads 32, 34, spray both surfaces of the fibrous mass 10 with a composition 36 containing a second fire retardant material forming a coating 40 on the outer surfaces of the fibrous mass 10. The coating 40 in article 50 is left that set; this last step can be facilitated by heating the article 50 with a heat source 42 to displace any water of the composition. The flame retardant and / or acoustic absorbent article described herein, avoids the use of glass fibers and materials that contain added formaldehyde. The article thus prepared, can be used in the manufacture of furniture, office separation panels, ceiling plates, bulletin board and other items and structures useful in office, school and industrial environments that require class A fire resistant structure and / or noise control. Articles made according to the present method also have satisfactory structural properties. For example, articles having a density in a range of 272.34 to 384.48 kg / m3 (17 to 24 pcf) were found to have a modulus of elasticity (MOE = Modulus of Elasticity) greater than 2,068.43 MPa (300,000 psi) through the width and more than 1861.58 MPa
(270,000 psi) through the length of multiple samples subjected to a three-point bending test modeled in accordance with ASTM D 1037-96a (the test deviates from the ASTM methods because the samples were not conditioned, the content moisture was not measured and the extension of sample size was higher than the standard or ASTM standard). In addition, the various samples were found to have modulus of rupture (MOR = Modulus of Rupture) greater than 13.10 MPa (1900 psi) across the width and more than 12.41 MPa
(1800 psi) through the length of the samples. EXAMPLE 1 A fibrous mass comprising about 20% by weight of polypropylene fibers and about 80% by weight of a natural fiber component is provided, the component contains 50% by weight of kenaf fibers and 50% by weight of hemp fiber industrial. The dough is heated to a temperature of about 190.56 to 193.33 degrees C (375 to 380 degrees F) for about 10 to 15 minutes in a conventional oven. The dough is compressed to a desired thickness and allowed to cool. Then, sodium polyporate powder is blown through the mass. Then, the compressed mass is sprayed on all surfaces with a 40% by weight aqueous solution of sodium silicate, at approximately 29.57-59.14 mi (1-2 oz.) In solution per .09 m2 (1 square foot) of Superficial area. The mass is then heated to a temperature of about 190.56 degrees C (about 375 degrees F) for about 1 to 2 minutes to displace the water and allow the sodium silicate coating to set. Structures made with the article can be useful in furniture, office dividers, ceiling tiles and the like. EXAMPLE 2 A fibrous mass is provided comprising about 20% by weight of polypropylene fibers and about 80% by weight of a natural fiber component, the component containing 50% by weight of kenaf fibers and 50% by weight of fibers of industrial hemp. Sodium polyporate powder is blown through the dough. The dough is heated to a temperature of about 190.56 to 193.33 degrees C (about 375 to 380 degrees F) for about 10 to 15 minutes in a conventional oven. The dough is compressed to a desired thickness and allowed to cool. The compressed mass is sprayed on all surfaces with an aqueous solution at 40% by weight of sodium silicate, at approximately 29.57-59.14 mi (1-2 oz.) In solution per .09 m2 (1 square foot) of surface area . The mass is then heated to a temperature of about 190.56 degrees C (about 375 degrees F) for about 1 to 2 minutes to displace the water and allow the sodium silicate coating to set. The resulting article can be used in the manufacture of a structure having a flame dispersion index of less than 25 and a smoke generation index of less than 450, which meets the requirements for a fire resistant article with Class A rating. Structures Elaborated with the article can be useful in furniture, office separations, ceiling plates and the like. Modifications and variations of the article and methods of the invention are possible in light of the above teachings. Therefore, it will be understood that within the scope of the appended claims, the invention may be practiced otherwise as specifically described herein.