MXPA00010207A - Foamed composite panel with improved acoustics and durability - Google Patents

Abstract

An acoustical panel formed from a fibrous, open-celled material comprised of up to about 50%by weight fibers, between about 3%and about 10%by weight binder, between about 20%and about 75%by weight filler and about 0.01%to about 2.0%by weight surfactant. Additionally, voids are formed within the panel having an average distribution size diameter of about 50 mu m to about 250 mu m. The acoustic panel achieves very high sound absorption properties without the need for additional surface perforations, while maintaining a very high surface hardness.

Description

'i COMPOUND PANEL WITH ACOUSTIC PROPERTIES AND IMPROVED DURABILITY.

Field of the Invention The present invention relates to a composite material and its method of manufacture, wherein the composite material has improved acoustic and surface hardness properties for use as an acoustic panel.

Background of the Invention. The manufacture of acoustic panels with a moisture layer generally includes a wetting process which has separate water-diluted fiber streams, fillers and a linker which are mixed together to create a paste.

The fibers are either organic or inorganic. For reasons of fire resistance, fibers are generally inorganic. A typical linker is starch. Fills may include newspaper (which also acts as a linker) clay and perlite. A typical wet panel formation process comprises successive steps of depositing a wet paste on a conveyor, drain the water from the paste through the strainer. The process also includes the suction for the removal of the additional water, the pressing by roller to compress and extract the additional water finally dried from the paste by hot air as it adheres in the colander. When entering a dryer, the wet panel generally has a water content of 60 to 70%. One of the most important aspects of slab boards is an outstanding function of absorption. Craftsmen have employed many different techniques to increase the sound absorption of acoustic panels, including openings, fissures, and flutes. The noise reduction capacity is expressed in terms of the noise reduction coefficient (NRC) [CRR]. Historically, wet processed acoustic panels have not had a high noise reduction coefficient when compared to dry-processed slab boards, such as those made from fiberglass fibrous materials. However, there are many disadvantages associated with the use of fiberglass. These disadvantages include the cost of fiberglass in relation to natural fibers, the complexity and costs associated with the manufacture of fiberglass acoustic panels with organic binders, health, and environmental concerns associated with the use of organic solvents and organic binders in the manufacture of fiberglass acoustical panels, and the lack of strength associated with acoustic panels having interior cores comprising glass fiber materials. In the manufacture of wet processed acoustic panels, composite materials with sound absorption should achieve an acceptable level of sound absorbency. This is usually done by reducing the density of the panel or by increasing the thickness of the panel. Competing with the requirement of high acoustic absorbency is the need for a relatively rigid material to provide sufficient structural integrity and sufficient surface hardness to resist punctures and teeth which may occur during manufacture, transportation, installation or use of the material. product. Additionally, a minimum thickness is also desirable to decrease the cost of the materials associated with the manufacture of the acoustic panels of acoustically absorbent material.

Unfortunately, wet process materials that exhibit sufficient rigidity and hardness of surfaces are generally quite dense, have small, closed cells, and do not exhibit characteristics of acceptable sound absorption.

In addition, wet process materials with highly acoustically absorbent properties are much less dense due to the increased porosity, and therefore do not exhibit sufficient hardness and hardness properties of the surface required for acoustical panel applications. Additionally, because the traditional wet processing techniques require vacuum transportation through the cross section of the wet layer material to remove the water, the significant gradient of the porosity size rises through a cross section of the water. panel, which further degrades the * Acoustic attenuation properties and the resistance of the finished panel.

Frequently, craftsmen will increase the relative amount of fibers within the composition to increase the porosity of the material and the absorbency of the sound of the material. However, formulations containing high amounts of natural fibers, such as cellulose in combination with high amounts of perlite, usually can not achieve a uniform distribution of large open cell voids, because the fibers cellulosics collapse with one another during the vacuum drying process. In addition, the vacuum drying process tends to arrange the fibers in a two-dimensional configuration parallel with a plane on which the material of the wet layers lies, which decreases the multidimensional hardness of the finished product.

Finally, the pearlite tends to separate from the fibers and to float to the surface of the aqueous solution during the panel forming step, further weakening the final product.

For example, U.S. Patent No. 5,277,762 describes a material and manufacturing process which solves the problem of collapsing the perlite fiber by floating the dough before draining the water. The flotation process allows the use of high levels of cellulose and perlite, but at a relatively low density to maintain the high porosity required. Although this process achieves a low density material with properties desirable acoustics, the process produces boards that have a hardness and low rigidity on the surface. Other references illustrate the achievement of structural integrity at the cost of reducing the acoustic absorbency of the material. For example, U.S. Patent No. 5,395,438 discloses an acoustic slab composition that has no wool content and high levels of expanded perlite or mineral fillers with a starch gel linker to aid in the formation of a structurally sound acoustic panel mold. to the sound Although the resulting acoustic panel shows an acceptable hardness, the panel does not exhibit the noise reduction characteristics necessary for an acoustic panel application due to the density of the panel. Others have tried to make acoustic panels using a foam-making process to achieve sufficient sound absorbency. For example, U.S. Patent No. 3,444,956 discloses a foamed surface acoustic body of pigmented latex. This overlay structure, while providing acoustic transparency to the base board, does not exhibit sufficient hardness for an acoustic panel application and is therefore not desirable. Therefore, there is a need to create a modified wet process, to manufacture a new acoustic panel that has a high acoustic absorbency, but with the structural integrity and hardness of the surfaces sufficient to serve as an acoustic panel for use in ceilings and walls .

Summary of the Invention.

The present invention provides an acoustic panel formed from open cell fibrous material which comprises up to about 50% by weight of the fibers, between about 3% and about 10% by weight of the linker, between about 20% by weight of the fibers. % and approximately 75% by weight of filler and approximately 0.01% up to approximately 2.0% by weight of surfactant. Additionally, gaps are formed within the panel that have an average diameter of the distribution size of about 50 μm to about 250 μm. the holes are distributed evenly throughout the panel with very little striation.

In addition, an acoustic panel is described which comprises an open cell dry material formed from an aerated foamed pulp. The aerated foamed pulp comprises, a percentage of base moisture weight up to about 30% by weight of the fibers, up to 6% by weight of the linker; about 3% to about 45% of the filler, about 40% to 70% by weight of water and about 0.003% to about 1.2% by weight of the surfactant. The open cell dry material also has a dry density of between about 4.536 kg / cm3 and about 8.164 kg / cm3, and a CRR factor of at least one method to produce an acoustic panel comprises the steps of preparing a mixture dry fibers, linker and filler and then the transportation of the dry mix to a mixer. Subsequently the dry mix is mixed into a mixture to ensure proper distribution of the fibers in the binder and filler. After the dry mix is combined with water and a surfactant to form a paste, then the paste is aerated to form a foaming paste which is then dried. The holes are created as the foamy dough dries. The holes have an average diameter of the distribution size of approximately 50μm to approximately 250μm.

Suitable fibers for use with the present invention may include, but are not limited to, organic fibers such as paper-derived cellulosic fibers and paper products. Additionally, the composition may also utilize inorganic fibers such as, but not limited to, glass fiber, metal slag wool, rock wool or mineral wool. In addition, examples of fillers may include, but are not limited to, clay, perlite, limestone, diatomaceous earth, talc, silicates and wollastonite. Additionally, the composition may comprise any typical bonding material for the acoustic panel making material including, but not limited to, corn starch, modified starches, polyvinyl acetates, polystyrene acrylics, and polystyrene butadiene.

The material comprising the acoustic panel derived from the derived ingredients above exhibits good acoustic and structural characteristics due to the material manufacturing process. The process comprises the steps of drying the filled fiber and binder mixtures, until the fibers are well dispersed throughout the dry mix. The conveyor system feeds the dry mix to a high density mixer. Simultaneously, water and surfactant are added to the dry mix. The mixing process is stirred enough to wet and dry the mixes to create a foaming paste incorporating air into the mix. The mixer drives the foamed aerated paste to the lower portion of the mixer, into a pump and finally through an extrusion die. The extrusion die includes an elongated hole to exclude a sheet of foamed pulp on a conveyor for drying. The extruded sheet is dried by conventional means and then converted into an acoustic panel suitable for use.

In an alternative embodiment of the present invention, the surfactant can be added as a foaming liquid to further facilitate the creation of a foaming paste. The liquid, which would generally comprise water and surfactant, can be stirred to create a foam before its addition to the dry mix. In yet another embodiment, each material within the composition can be added by means of separate streams within a high density mixer to create the foaming material. The advantages of the composition and process of the present invention include a complete three-dimensional orientation of the fibers within the materials to ensure the increased strength of the material and the hardness of the surface. The relative size range of the holes within the paste is narrow since vacuum is not applied through the paste. Additionally, there is no gradient in the size of the holes in the cross section of the panel that can be seen. The narrow range of hole sizes, and the virtual elimination of the hole size gradient in the cross-sectional thickness of the panel increases the acoustic absorbency of the panel while also increasing its mechanical strength.

Detailed Description of the Drawings. Figure 1 schematically illustrates the process for the production of a composite cementitious material of the present invention.

Detailed Description of the Invention. The present invention provides an acoustic panel that combines resistance with high noise reduction formed from fibrous open cell material using a modified wet forming process. The open cell fibrous material comprises up to about 50% by weight of fibers, between about 3% and about 10% fiber of linker weight in about 20% and about 75% by weight of filler, and between about 0.01% to about 20% by weight of the surfactant. Additionally, gaps are formed within the panel that have an average diameter of size distribution of approximately 50μm to approximately 250μm. The formed holes are distributed evenly throughout the panel with very little striation. The composition for the acoustic panel includes a dry mix comprising fiber material, stuffing material and the binding material. Suitable fibers may include, but are not limited to, organic fiber material such as wood cellulosic fibers or paper sheets. In one embodiment, the composition includes divided cellulosic fibers derived from wood products for the fiber component. The composition may also utilize inorganic fibers such as, but not limited to, fiberglass, metal slag wool, rock wool or mineral wool. In one embodiment, the composition may include a filler comprising clay and pearlite. Other acceptable fillers may include, but are not limited to, limestone, diatomaceous earth, talc, silicates or wollastonite. Finally, the composition includes a typical bonding material for the acoustic panels that includes, but is not limited to, corn starch, modified starches, acetates polyvinyl, acrylic polystyrene, and polystyrene butadiene. The composition also includes a surfactant to induce foam generation of the ingredients. The composition in its wet form may include 0% to 30% by weight of inorganic fibers, about 1.5% to about 21% by weight of cellulosic fibers, from about 3% to about 36% by weight of clay, from about 3% to about 45% by weight of perlite, from about 1.2% to about 6% by weight of starch, from 0% to 6% by weight of secondary linker and from about 40% to 70% by weight of water, and from about 0.003% to about 1.2% by weight of surfactant, with a dry density of approximately 0160.2 kgs / 0288.36cm3. As set out in the following examples, the composition may also include non-ionic or anionic surfactants. Surfactants may include sodium laureth sulfate (1) (sold by Stepan Steol as CS 130), ammonium sulfate sulphate (3) (sold by Stepan Cedepal as FA-406), an oligomeric proprietary sample (sold by Stepan as Alpha Foamer) or sodium dodecylbenzene sulfonate (sold by Stapan as Biosoft D-40). These surfactants can be used in combination or alone to create the foam. A suitable surfactant is sodium dodecylbenzene sulfonate. A suitable secondary linker may include starch graft polystyrene acrylic, commercially known as Sequabond, ® a trademark of Sequa Chemicals, Inc., of New York, New York. Other suitable secondary linkers may include, but are not limited to, any type of starch, polystyrene, polyvinyl acetate, polystyrene acrylics and styrene butadiene. Figure 1 schematically illustrates process 1. The method comprises the steps of the dry mix of pre-weighed amounts of fiber 8, pearlite 4, starch (or linker) 2 and clay 6 until the fibers are well dispersed within the dry mix. After weighing the ingredients on a scale 10, a weight conveyor 12 feeds the dry ingredients to a mixer 14 through a hopper and onto a conveyor 16. The variable speed pumps 26, feeds water 20 and the surfactant 22 through the flow meter motors 28 to a static mixer 30. A high intensity mixer 18 receives the dry mix, the secondary linker 24, if any, and the mixture of water 20, and surfactant 22. Optionally, the water 20 and the surfactant 22 can be diverted from the mixer 32 and sent directly into the static mixer 30. If the mixer 32 is used, the air 34 is introduced into the water and the surfactant to form a foam. The high intensity mixer 18 creates a foam from water 20, surfactant 22 and air (open to the atmosphere) to create a wet foaming paste. A column 38 receives the foamy mixture and a positive displacement pump 39 feeds the foamy mixture through die 40. In one embodiment, applicants have discovered that continuous high density Autocon mixing apparatuses work well as a high intensity mixer. to add the liquid to the dry mix, and aerate the paste. On behalf of Autocon ® is a registered trademark of Autocon Continuous Processing. Systems, Inc. of Santa Rosa, California. The high intensity mixer 18 essentially comprises two concentric cylindrical drums. An inner drum rotates while the outer drum remains stationary. The solid cylindrical space between the drums defines the volume of the mixture. The inner drum includes impellers that protrude into the mixed space to agitate and aerate the mixture. The weight conveyor 16 feeds the dry mix to the continuous high intensity mixer 18 while the inner mix drum, agitates the water 20, the surfactant 22 and the linker 24 into the dry mix from a point of about one third ( 1/3) of the descending path from the top of the rotating drum. The high intensity mixer 18, it agitates the liquid at 800 rpm radially outwards from the axial center of the mixer 18 to create the wet paste, while aerating the paste to create the foamy pulp. In one embodiment, the mixer 18 leads the foamed pulp aerated down to the bottom portion of the high intensity continuous mixer and into the column 38, which is approximately 1.2202 meters high, and leads at an inlet of the positive displacement pump 39. The positive displacement pump 39 pressurizes and feeds the foamy paste to the extrusion die 40. The extrusion die 40 includes an elongated hole for extruding a sheet 43 of the foamed pulp on a conveyor mesh for drying. In an alternative embodiment, the die may extrude the foamed pulp onto a previously placed thin canvas material, a conventional acoustically formed wet panel or directly onto the conveyor to form the panels from the foamed wet pulp. Although the hole of the die can comprise virtually any direction, one embodiment includes a width of approximately 60.96 cm. and a height of about 0.635 cm to about 3.175 cm.

In another embodiment, the process forms an acoustic or board panel from a foamed pulp that is from about 0.635 cm to about 3.175 cm thick, with a bulk density of about 0.625 kg / 3, 175 cm3 to about 6.8040 kg / 0.3048 cm3, although the densities can vary considerably depending on the exact formulation. An acoustic panel formed of an aerated paste can have a CRR factor of at least 0.65 and a surface hardness of at least 49.8960 kg / 0.3048cm3. In one embodiment, the process can form the acoustic panel by molding the aerated paste, or by giving the aerated paste the form of panels with rollers or long blades. Additionally, the process can include the passage of aerated paste formation in an acoustic panel previously formed using extrusion, rollers and long blades to create a composite acoustic panel. Sparkling pulp provides many cells or voids within the paste. As the paste is dried, the bubbles form the intersecting cells. As the pulp does not need to be vacuum dried, the fibers are left in a three dimensional random orientation increasing the final strength of the composite and the hardness of the surface. Additionally, the lack of vacuum drying reduces or eliminates the hole size gradient as a function of the cross-sectional position of the panel. In one embodiment, the size of the voids has a range from about 50μm to about 250μm. In an alternative embodiment of the present invention, the mixer 32 may also pre-foam the water and the surfactant before being combined with the mixture of filled fibers and dry linker. A pump can then transmit the water-surfactant foam to a high intensity mixer 18 where additional foam formation occurs by further agitation and aeration of the dry mix. For purposes of clarity and for the comparison of the performance characteristics of the panel and its manufacturing process, the Applicants have measured, the acoustic performance, the hardness of the surface and the size of the cell, of several panel samples using standard techniques. known in art. More specifically, in order to compare the acoustic performance characteristics of the present invention with those of other acoustic panels of the art, the Applicants measured the acoustic absorption properties of the boards of compounds made in relation to the present invention directly in terms of the reduction coefficient. of noise (CRR), as mentioned in the background of the invention. The Applicants derive the CRR from a standard test method in accordance with the ASTM C423-84a test designation, where sound absorption is measured in a specific range of frequencies. The Applicants also use the impedance test and airflow resistance measurements to measure the acoustic performance of the material. The impedance test uses standard and test specifications set forth in ASTM C384. The ohms acoustic resistance test in flow air uses standard and test specifications stated in ASTM C522-87. To measure the hardness of the surface of the acoustic panel formed by this process, the Applicants use the hardness test specification established in ASTM C367-95, Sections of the 2 to 7. More specifically, ASTM C376-95 standards require the recording of a force required by 5.08 cm diameter spheres to penetrate 0.635 mm inside the acoustic panel. Finally, the Requesters measured the size of the holes and the distribution within each sample using the mercury intrusion porosimeter that has a model name of Micromeritics Autopore II 9220. In each of the samples of the examples set forth above, the Requesters compare the performance characteristics of the acoustic panel with performance characteristics similar to an acoustic panel described in US Patent No. 5, 395,438. Direct comparisons of the relevant performance characteristics of the present invention with those of U.S. Patent No. 5,395,438 demonstrate improvements in acoustic performance while maintaining the hardness properties of the surface of the present invention. For the examples provided in the present description, the Applicants have defined clays having a minimum surface area of 10 m2 / g. This is measured using nitrogen as the absorbate in the Micromeritics ASAP 2000 (BET Surface Area method). The following examples are only examples taken from acoustic panels manufactured in accordance with the process described in the present description. The examples are not intended to limit selections of material compositions that may comprise an acoustic panel manufactured in accordance with the present invention. The examples are also not intended to limit material properties associated with an acoustic panel manufactured in accordance with the process described in the present description. Unless otherwise stated, the percentages are percentage of dry weight.

Example 1 ('polystyrene acrylic starch graft linker) ("sodium dodecylbenzene sulfonate surfactant) (*** calculated from impedance tube / average of four frequencies) The Applicants manufactured the acoustic panel of Example 1 according to one embodiment of the present invention. Example 1 illustrated above establishes the different percentages of weight of the constituents of the dough. The Applicants mixed dry wood fiber, perlite, starch, linker and clay so that the fibers were well dispersed and all the material was well mixed. The Applicants transported the dry mix to a high intensity mixer and then added the surfactant water. The high intensity mixer pulled air into the pulp to generate the foamed pulp, as described in relation to Figure 1. In the Exemplary, the foamed pulp leaving the mixer was about 65% water and about 35% solids on a base by weight. In a volume basis, the foaming paste was approximately 39% water and approximately 21% solids and approximately 40% air. The board was formed by molding the foam into sheets. This board was added sand to a thickness of approximately 1.4524 cm with a volume density of 5.4432 kg / 0.3048 cm3. The acoustic panel manufactured in [Example 1 above] included a range of hole sizes from about 100 μm to about 150 μm. Example 2 (* graft linker of polystyrene acrylic starch) (** sodium dodecylbenzene sulfonate surfactant) (*** calculated from I-impedance tube, four frequencies) (**** Owens Corning 0.635 m 16 microns) The Applicants manufactured the acoustic panel of Example 2 according to one embodiment of the present invention. Plus specifically, they mixed dry wood fiber, perlite, starch and clay so that the fibers were well dispersed and all the materials were well mixed. They then transported the dry mix to a high intensity mixer and then added water, the linker and the surfactant. The high intensity mixer pulled air into the paste to generate foam. In Example 2, the foaming paste from the mixer was about 65% water and about 35% solid on a weight basis. In a volume basis, the foaming paste was about 39% water, about 21% solids and about 40% air and was molded into a hand sheet to form a board. This board was applied sand up to a thickness of 1.4524cm with a volume density of 6.03288 kg / 0.3048cm3. The best comparison is to demonstrate the improvements in performance provided by the board of the layers when applied to a single layer acoustic board for the roof. The following examples of foamed sheet boards in a base with high wool content demonstrates the improvements in the CRR factor as a further improvement in hardness. Example 3 (the CRR factor of the board is from a full scale test, average of four frequencies) (hardness of the composite board is the value of the layers tested separately).

The present invention provides improved acoustic performance and improved mechanical strength for the following reasons. The narrow range in the size of the holes in the whole material allows a material structure consisting of open cells for improved sound absorption. Additionally, the elimination of the gradient of the size of the holes in the entire cross section of the acoustic board improves the acoustic performance of the board allowing the material consisting of open cells. The Applicants also consider that the consistent structure of open cells of the present invention improves the mechanical strength and hardness of the surface of the acoustic panel.

The Applicants believe that the mechanical properties mentioned above are achieved due to the unique manufacturing process as described above. The manufacturing process provides a high intensity mixer which allows the mixing of all dry ingredients before the addition of water and other liquids to the mixture. The high intensity mixer agitates the wet and dry mixtures enough to create an aerated mix which is extruded immediately through a die to create a sheet, thus allowing the formation of the open cell composite having a Narrow range of hole sizes and virtually no gap size gradient as a function of the transverse position.

Although the Applicants have presented the modalities as illustrated and described above, it is recognized that variations can be made with respect to the relative percentages of weight of the different constituents in the composition. Therefore, although the present invention has been described only in various forms, it will be obvious to those skilled in the art that many additions, cancellations and modifications may be made to it without departing from the spirit and scope of the present invention, and that undue limits should not be imposed on it except those established in the following Claims.

Claims (32)

1. CLAIMS Having described the present invention, it is considered as a novelty and, therefore, the content of the following CLAIMS is claimed as property: 1 . An acoustic panel formed of an open cell fibrous material which comprises: up to about 50% by weight of dry fibers; between about 3% and about 10% by weight of dry linker; between about 20% and about 75% by weight of dry filler; and about 0.01% to about 2.0% by weight of dry surfactant; the hollow material having an average distribution size diameter of about 50μm to about 250μm.
2. 2. The acoustic panel as described in Claim 1, further characterized in that the panel is formed of a foamed aerated paste including a surfactant, fibers, linker, and filler.
3. 3. The acoustic panel as described in Claim 1, further characterized in that the surfactant is selected from the group consisting of sodium laureth sulfate, ammonium sulfate, and sodium dodecylbenzene sulfate.
4. The acoustic panel as described in Claim 1, further characterized in that the filling is selected from the group consisting of kaolin, clay, perlite, limestone, diatomaceous earth, talc, silicates and wollastonite.
5. The acoustic panel as described in Claim 1, further characterized in that the fibers are cellulosic fibers.
6. The acoustic panel as described in Claim 1, further characterized in that the fibers are selected from the group consisting of glass fibers, slag wool and rock wool.
7. The acoustic panel as described in Claim 1, further characterized in that the fibers are synthetic fibers.
8. The acoustic panel as described in Claim 1, further characterized in that the linker is selected from the group consisting of starch, polystyrene, polyvinyl acetate, polystyrene acrylics and styrene butadiene.
9. 9. The acoustic panel as described in Claim 1, further characterized in that the panel has a CRR coefficient of at least 0.65.
10. 10. The acoustic panel as described in Claim 1, further characterized in that the panel has a surface hardness of at least about 49.8960 kg / 0.3048cm3. eleven .
11. The acoustic panel as described in Claim 1, further characterized in that the panel has a density of about 5.4432 kg / 0.3048 cm3 to about 6.8040 kg / 0.3048 cm3.
12. 12. An acoustic panel which comprises: an open cell dry material formed from an aerated foamed pulp which comprises a weight basis in a wet percentage: up to about 30% by weight of the fibers; up to about 6% by weight of the linker; from about 3% to about 45% by weight of filler; from about 40% to about 70% by weight of water; Y from about 0.003% to about 1.2% by weight of the surfactant; having the dry material of open cells a dry density of between about 4.536kg / 0.3048cm3 and about 8.164kg / 0.3048cm3, and a CRR factor of at least 0.65.
13. 13. The acoustic panel as described in Claim 12, further characterized by additionally including gaps formed within the panel having an average diameter of distribution size from about 50μm to about 250μm.
14. 14. The acoustic panel as described in Claim 12, further characterized in that the density of the open cell dry material is about 5.4432 kg / 0.3048 cm3 to about 6.8040 kg / 0.3048 cm3.
15. 15. The acoustic panel as described in Claim 12, further characterized in that the aerated foamed pulp further includes a second surfactant.
16. 16. The acoustic panel as described in Claim 12, further characterized in that the surfactant is selected from the group consisting of sodium laureth sulfate, ammonium sulfate, and sodium dodecylbenzene sulfonate.
17. 17. The acoustic panel as described in Claim 12, further characterized in that the filling is selected from the group consisting of kaolin, clay, perlite, limestone, diatomaceous earth, talc, silicate and wollastonite.
18. 18. The acoustic panel as described in Claim 12, further characterized in that the fibers are cellulosic fibers.
19. 19. The acoustic panel as described in Claim 12, further characterized in that the fibers are selected from the group consisting of glass fiber, slag wool and rock wool.
20. 20. The acoustic panel as described in Claim 12, further characterized in that the fibers are synthetic fibers. twenty-one .
21. The acoustic panel as described in Claim 12, further characterized in that the linker is selected from the group consisting of starch, polystyrene, polyvinyl acetate, polystyrene acrylics and styrene butadiene.
22. 22. The acoustic panel as described in Claim 12, further characterized by having a surface hardness of at least about 39.8960 kg / 0.3048cm3.
23. 23. The production method of an acoustic panel which comprises the steps of: dry mixing the fibers, the linker and the filler to create a dry mix to distribute the fiber the linker and the filler into the mixture; the addition of water and a surfactant to the dry mix to create a paste and aerated the dough to produce a frothy paste; drying the foaming paste to create a dry paste; thereby forming voids within the dry pulp having an average diameter distribution size from about 50μm to about 250μm.
24. 24. The method as described in Claim 23, further characterized in that the mixing of the fibers, the linker and the filler are distributed in a substantially uniform manner within the mixture.
25. 25. The method as described in Claim 23, further characterized in that the surfactant is added in liquid form to facilitate the generation of foam from the pulp.
26. 26. The method as described in Claim 23, further characterized in that the surfactant is added in dry form to the dry mixture before mixing with the liquid.
27. 27. The method as described in Claim 23, further characterized in that it additionally includes the generation of foam from the water and the surfactant before adding the water and the surfactant to the dry mixture.
28. 28. The method as described in Claim 23, further characterized in that the water and the surfactant are added to the dry mix in a continuous high intensity mixer.
29. 29. The method as described in Claim 23, further characterized in that it additionally includes extruding the foamed pulp to form the acoustic panel.
30. 30. The method as described in Claim 23, further characterized in that it additionally includes molding the foamed pulp to form the acoustic panel.
31. 31 The method as described in Claim 23, further characterized in that it additionally includes shaping the foamed pulp.
32. 32. The method as described in Claim 31, further characterized in that the foamed pulp is formed by means of long blades to form the acoustic panel. The method as described in claim 31, further characterized in that the foamed pulp is formed because the foamed pulp is given the shape of an acoustic panel within rolls. The method as described in [Claim 23, further characterized in that it additionally includes the application of the foamed pulp in a previously formed acoustic panel to create a composite acoustic panel.