TWI460339B - Panels including renewable components and methods for manufacturing - Google Patents

Description

Plate containing renewable components and method of manufacturing same

The present invention relates to panels for the construction industry which comprise a renewable component to improve the sound absorption and physical properties of the panel. The invention also provides a method of making such a panel.

The panels used as tiles or walls are part of the architectural product and provide architectural value, sound absorption, sound absorption attenuation, and practical functions within the building. In general, a panel such as a sound absorbing panel is used in an area where noise control is required. Such areas are, for example, office buildings, department stores, hospitals, hotels, auditoriums, airports, restaurants, libraries, classrooms, theaters, and cinemas, as well as residential buildings.

To provide architectural value and practical functionality, for example, the sound absorbing panels are substantially flat and self-supporting to be suspended from a typical ceiling hard system or the like. Therefore, the sound absorbing panel has a certain degree of hardness and rigidity, which can usually be measured by its Modulus of Rupture (MOR). In order to obtain the desired sound absorbing characteristics, the sound absorbing panel also has the characteristics of sound absorption and low sound penetration.

Sound absorption is usually measured by its Noise Reduction Coefficient (NRC) as described in ASTM C423. The NRC is represented by a number between 0 and 1.00, which indicates the level of sound that is absorbed. A sound absorbing panel with an NRC value of 0.60 absorbs 60% of the sound transmitted to the sound absorbing panel and reflects 40% of the sound. Another test method is to estimate NRC (estimated NRC, eNRC) using an impedance tube as described in ASTM C384.

The ability to reduce sound penetration is measured by the Ceiling Attenuation Class (CAC) value as described in ASTM E1414. The CAC value is measured in decibels (dB) and represents the amount of sound that is reduced as the sound penetrates the material. For example, a sound-absorbing panel with a CAC value of 40 can reduce the sound of penetration by 40 decibels. Similarly, sound penetration reduction can also be measured by its Sound Transmission Class (STC) as described in ASTM E413 and E90. For example, a board with a 40 STC value can reduce the sound of penetration by 40 decibels.

Sound absorbing panels made according to various industry standards and building codes have a fire rating of Class A. According to ASTM E84, a flame spread index below 25 and an aerosol generation index below 50 are required. Airflow resistance, a measure of mat porosity, was tested according to the modified ASTM C423 and C386 standards. In addition, the MOR, hardness and sag of the sound absorbing panel were tested in accordance with ASTM C367. The increased porosity of the base mat improves sound absorption but cannot be measured by any specific industry standard or building code.

Due to the rate and efficiency of the water-felting process, it is currently preferred in the art to use the process to make most sound absorbing panels or tiles. In the water felting process, the substrate mat is formed by a method similar to the paper making method. One of the types of such a process is described in U.S. Patent No. 5,911,818, the disclosure of which is incorporated herein by reference. First, an aqueous slurry comprising a diluted aqueous dispersion of mineral wool and a lightweight aggregate is transferred to a moving perforated line of a Fourdrinier-type pad forming machine. The water is drained by gravity from the slurry and then optionally removed by vacuum suction and/or extrusion as needed. Again, the base pad of water will be removed, which may still retain some of the water and be placed in a heated oven or kiln to remove residual moisture. A panel of acceptable size, appearance and sound absorbing properties can be obtained by processing the dried substrate mat. Machining trimming includes surface grinding, cutting, perforating/texturing, roller/spray coating, edge cutting, and/or laminating the sheet onto a scrim or screen.

The composition of a typical sound absorbing panel base mat comprises inorganic fibers, cellulose fibers, binders, and fillers. As is well known in the industry, the inorganic fibers can be mineral wool (which can be replaced with slag wool, rock wool, and stone wool) or glass fibers. Mineral wool is formed by first melting slag wool or rock wool at 1300 ° C (2372 ° F) to 1650 ° C (3002 ° F). The molten ore is then spun into a yarn in a fiberizing spinning machine by a continuous stream of air. The inorganic fibers are thick and provide the base mat and porosity. Conversely, cellulosic fibers are used as structural components to provide strength to wet base mats and dry base mats. This strength is derived from the myriad hydrogen bonds formed by the various components of the cellulosic fibers and the substrate mat, which is a result of the hydrophilic nature of the cellulosic fibers.

A typical base pad binder used is starch. Typical starches used in sound absorbing panels are unmodified, uncooked starch granules which are dispersible in the aqueous board slurry and which are generally evenly dispersed in the substrate mat. Once heated, the starch granules are cooked and dissolved to provide the board component bonding ability. Starch not only promotes the bending strength of the sound absorbing panel, but also promotes the hardness and rigidity of the panel. In some plate compositions with high concentrations of inorganic fibers, latex binders are used as the primary binder.

Typical base pad packings contain heavy and light inorganic materials. The primary function of the filler is to impart bending strength and to provide board hardness. That is, the term "filler" is used in the present disclosure. It should be understood that the unique characteristics and/or characteristics of each filler may affect the rigidity, hardness, sag, sound absorption and sound penetration in the panel. Examples of heavy fillers include calcium carbonate, clay or gypsum. Examples of lightweight fillers include expanded perlite. As a filler, the expanded perlite has the advantage of being bulky, thereby reducing the amount of filler required in the substrate mat.

One of the disadvantages of expanded perlite is that the perlite particles have a tendency to fill the pores of the base mat and seal the surface thereof, which can affect the sound absorption capacity of the board. In addition, expanded perlite is relatively fragile and fragile during the manufacturing process. In general, the greater the amount of expanded perlite used, the worse the sound absorbing properties of the board. The expansion of perlite wastes a significant amount of energy. When the perlite ore is introduced into an expansion tower heated to about 950 ° C (1750 ° F), expanded perlite is formed. The water in the perlite structure is converted to steam and the resulting expansion causes the perlite to pop open like a popcorn to reduce the density to about one tenth of the unexpanded material. The lower bulk density of the expanded perlite allows it to flow upwardly in the expansion tower and can be collected by a filtration device. This process uses a relatively large amount of energy to heat all perlite to a temperature sufficient to evaporate the water within the perlite.

Taking into account the current trends in the construction industry, products that do not pollute the environment are needed, that is, processes that can reduce greenhouse gases, acidification, smog, water eutrophication, solid waste, major energy consumption, and/or water emissions. Naturally grown, renewable materials can be used to make environmentally friendly building products. In the construction industry, wood is a widely used renewable material, but it only provides low sound absorption. Similarly, a large amount of construction waste and by-products, as well as wood and furniture industry waste, are readily available, but are limited in the production of building materials.

In order to use naturally grown renewable materials, the fibers must be extracted. This can be accomplished by slurrying, for example, wood, cedar, bamboo, and other lignocellulosic materials, chemically or mechanically destroying the plant material into individual fiber cells. A common chemical pulping process uses sodium sulfide, sodium hydroxide or sodium sulfite to dissolve lignin at about 150 ° C (302 ° F) to about 180 ° C (356 ° F), thereby reducing about 40% to 60%. Fiber biomass. Conversely, the thermomechanical pulping process places the wood chips at high temperatures (about 130 ° C (266 ° F)) and high pressure (about 3 to 4 atmospheres (304 to 405 kPa)) to soften the lignin and mechanically Fibroblasts rupture. The cleavage of the lignin bond causes defiberization of the material and causes a loss of about 5% to 10% of its biomass. Both chemical and thermomechanical pulping processes require significant amounts of energy to turn the lignocellulosic material into individual fibers. Moreover, such a large portion of biomass loss will also increase the cost of raw materials.

Many U.S. patents teach the use of renewable materials in building materials. U.S. Patent No. 6,322,731 discloses a method of forming a building panel having an indefinite length, the panel comprising an organic particulate substrate material comprised of a plurality of rice hulls and a binder. Due to the structural integrity requirements, the process requires a combination of high temperature and high pressure to form a plate of sufficient strength. Because of the high density and low porosity of the resulting panels, they have relatively low sound absorption. Thermal insulation and sound insulation properties can be achieved through a closed cavity.

U.S. Patent No. 5,851,281 discloses a process for the manufacture of a cement waste material composite wherein the waste material is rice bran. The rice bran is heated to near 600 ° C (1112 ° F) in the absence of oxygen to produce fine particles.

U.S. Patent No. 6,443,258 discloses a sound absorbing porous sheet formed from a cured, water-containing, foamed, viscous material. The panel provides good sound absorption performance with increased durability and moisture resistance. Rice husk ash may be added to increase the overall hardness of the expanded cement board.

A board for use as a building material with improved sound absorption and physical properties is provided. The panels of the present invention comprise a renewable component, such as rice husk, and have improved sound absorbing properties comprising a CAC or STC that maintains a relatively constant. In addition, the improved NRC can be maintained while maintaining or improving other physical properties of the board, including MOR, hardness, airflow resistance, and sag.

In one embodiment, the panels of the present invention comprise from about 0.1% to about 95% by weight of one renewable component. The panel has at least one of a CAC value of at least about 25, an NRC value of at least about 0.25, and an STC value of at least about 25.

Some other embodiments of the panels of the present invention comprise a core comprising from about 0.1% to about 95% by weight of one of the ground renewable ingredients, from about 0.1% to about 95% by weight of one or more fibers, about From 1% by weight to about 30% by weight of one or more binders, and from about 3% by weight to about 80% by weight of one or more fillers, based on the weight of the dry board. The ground recyclable component has a particle size distribution such that less than 5% of the particles remain in a mesh screen having an opening of about 0.312 inches and less than 5% of the particles pass through a having a 0.059 inch Open mesh screen.

In another embodiment, a method of making a panel for use as a building material comprises the steps of forming an aqueous slurry comprising from about 0.1% to about 95% of the renewable component and water. A base pad is then formed from the slurry using a foraminous production line. The water from the substrate mat is removed and processed to trim the substrate mat to form a panel for use as a building material. The panel produced by this method has at least one of a CAC value of at least about 25 and an NRC value of at least about 0.25.

At least one other embodiment is a method of making a panel for use as a building material, comprising the steps of: selecting a ground renewable component; and water and from about 0.1% to about 95% by weight of the renewable component, about 1% by weight to about 50% by weight of one fiber, about 1% by weight to about 30% by weight of one of the binders, and about 3% by weight to about 80% by weight of one of the fillers are combined to form an aqueous slurry; In the production line with holes, a base pad is formed from the aqueous slurry; water is removed from the substrate pad and processed to trim the substrate pad. The renewable components are screened to obtain the aforementioned particle size distribution. The panel produced by this method has at least one of a CAC value of at least about 25 and an NRC value of at least about 0.25.

The addition of a ground or milled renewable component is advantageous in that the energy required to prepare the renewable component is lower than other filler materials. The renewable component is preferably ground or incorporated directly into the sound absorbing panel. In this process, energy is only consumed when the regenerable component is ground and/or sieved, and less energy is used than expanded perlite.

Another advantage of using a renewable material is that there is no significant loss of biomass in the preparation of the renewable composition. The milled or milled renewable component maintains its bulk structure without chemical modification or chemical structural changes, such as release. The retention of biomass allows the purchased materials to be used more efficiently, thereby reducing their cost.

The choice of fillers to be used in building panels often undesirably alters the characteristics of the panels. However, the use of the renewable components of the present invention reduces energy and raw material costs while maintaining or improving other physical properties of the board.

The products, methods and compositions described herein are intended to be applied to the panels of construction materials. In particular, the panels can also be used as ceiling products, sound absorbing panels or tiles. The following discussion is directed to a sound absorbing panel as an embodiment of the present invention; however, this is not intended to limit the invention in any way.

The fiber system is present in the sound absorbing panel in the form of inorganic fibers, organic fibers or a combination thereof. The inorganic fibers may be mineral wool, slag wool, rock wool, asbestos, fiber glass or a mixture thereof. The inorganic fibers are viscous and provide a base mat and porosity. The inorganic fibers are present in the sound absorbing panel in an amount of from about 0.1% by weight to about 95% by weight, based on the weight of the sheet. At least one embodiment of the sound absorbing panel uses mineral wool as the preferred fiber. An example of a cellulose fiber, an organic fiber, is used as a structural component to provide strength of a wet substrate pad and a dry substrate pad derived from hydrogen bonds formed by various components of the cellulosic fiber and the substrate pad. The result of the hydrophilic nature of cellulose fibers. The cellulosic fibers in the substrate mat are from about 1% to about 50% by weight, more preferably from about 5% to about 40% by weight, most preferably from about 10% to about 30% by weight, based on the weight of the board. Preferred cellulosic fibers are derived from recycled newsprint.

The panel comprises at least one component that is a renewable material. Renewable materials are defined as wood or non-wood plants, or parts of wood or non-wood. These renewable components are preferably lignocellulose, which comprises cellulose and lignin. Possible sources of these materials are waste materials or by-products from the agricultural, agro-industry, forestry and/or construction industries.

An example of a renewable ingredient is rice husk or rice blast. Examples of other renewable ingredients include, but are not limited to, wheat bran, oat hull, rye whisk, cotton husk, coconut shell, corn bran, corn cob, rice straw stalk, wheat Straw, barley straw, oat straw, rye straw, bagasse, thatch, Espart, Sabai, flax, kenaf, jute , hemp, ramie, abaca, sisal, saw dust, bamboo, wood chips, sorghum stalks, sunflower seeds, buckwheat Shell, nut shell containing peanut shell and walnut shell, other similar materials and mixtures thereof.

The regenerable component is preferably reduced in size prior to mixing with other board components. The recyclable material preferably has a particle size that passes through a mesh screen having an opening of 0.312 inches (2.5 mesh, as defined by the ASTM screen table) and retained in a mesh screen having an opening of 0.0059 inches (100). Mesh, as defined by the ASTM screen table). In some embodiments, the renewable ingredients are used in their entirety or in the form received from the supplier. The term "renewable component" is intended to include intact granules or sized granules of any size known in the art, including grinding into a powder, cutting into strips, grinding, milling, sieving or Combined granules. Optionally, downsizing is achieved by mechanical processes, such as grinding or milling, to achieve the desired size. At least one embodiment uses a sputum-type device.

Optionally, the regenerable ingredients are sieved through a sieve having a particular mesh size to achieve the desired particle size distribution. The coarse chips that are too large to pass the desired maximum screen are removed as needed and repeated until the resulting material can pass through the screen. In one embodiment, the ground rice husks are first sieved through a #30 mesh screen to remove larger particles, which are then sieved through a #80 mesh screen to remove the fine particles. The sound absorbing panels were made using a treated shell that passed through a #30 mesh screen and remained on the #80 mesh screen. In this embodiment, the material passed through the #80 mesh screen cannot be used in the board. The #30 mesh screen has an opening of 0.022 inch or 0.55 mm. The #80 mesh screen has an opening of 0.007 inch or 180 microns. In another embodiment, a sound absorbing panel is fabricated using a treated shell directly from a rice milling plant. Optionally, the particle size distribution of the regenerated material ground into a powder has at least about 95% of the particles passing through the #30 mesh screen and no more than 5% of the particles passing through the #80 mesh screen from the U.S. sieve set ( US Sieve Set).

As discussed in the prior art, expanded perlite is a material commonly used in building panels. When used in ceilings, expanded perlite tends to form a structure without interconnected pores. The introduction of ground or milled regenerable components into the sound absorbing panel can help block the structure of the expanded perlite, thereby increasing the interconnected pores. A plate containing milled regenerable components in addition to perlite has more porosity and can achieve higher sound absorption than a plate with only perlite without any ground or milled renewable components. Sex.

It has been found that the larger the particle size of the regenerable component, the higher the sound absorption value. The optimum particle size distribution for any of the embodiments depends on the desired sound absorption value.

It will be appreciated that the particle size distribution of the renewable ingredients is suitable for other components, such as fibers, expanded perlite, etc., to form a homogeneous and uniform slurry. Forming a uniform slurry produces a homogeneous and uniform substrate mat. The particle size distribution is preferably selected to maintain or improve the physical integrity of the panel.

In some embodiments, the renewable component comprises less than about 5% by weight of the particles remaining on the #6 mesh. In other embodiments, the renewable ingredients used comprise less than 5% by weight of the particles retained on the #20 mesh. In still other embodiments, the milled or milled renewable ingredients used comprise less than about 5% by weight of the particles retained on the #30 mesh. Preferably, the renewable component has a bulk density of from about 5 to about 50 pounds per cubic foot (80 to 800 kilograms per cubic meter), preferably from about 10 to about 40 pounds per cubic foot (160 to 640 kilograms). The bulk density of /m3) is preferably a bulk density of from about 20 to about 35 pounds per cubic foot (320 to 560 kilograms per cubic meter). The #6 mesh screen has an opening of 0.132 inches or 3.35 mm, the #20 mesh screen has an opening of 0.312 inches or 800 microns and the #30 mesh screen has an opening of 0.022 inches or 0.55 mm.

Optionally, starch may be included in the base mat as a binder. Typical starches are unmodified, uncooked starch granules which are dispersible in an aqueous slurry and are generally evenly dispersed in a substrate mat. The substrate mat is heated, and the starch granules are cooked and dissolved to bond the plate components to each other. Starch not only promotes the bending strength of the sound absorbing panel, but also improves the hardness and rigidity of the panel. Further, as desired, the base mat may comprise from about 1% to about 30% by weight starch, more preferably from about 3% to about 15% by weight, most preferably from about 5% to about 10% by weight, to the board Weight.

Typical base pad packings contain heavy and light inorganic materials. Examples of heavy fillers include calcium carbonate, clay or gypsum. It is considered that other fillers can also be used in the sound absorbing panels. In one embodiment, from about 0.5% to about 10% by weight of calcium carbonate is utilized, based on the weight of the board. It is also possible to use from about 3% by weight to about 8% by weight of calcium carbonate, based on the weight of the board.

An example of a lightweight filler is expanded perlite. The bulk of the expanded perlite reduces the amount of filler used for the substrate mat. The main function of the filler is to improve the bending strength and hardness of the board. Although the term "filler" is used throughout this discussion, it should be understood that the unique characteristics and/or characteristics of each filler affect the rigidity, hardness, sag, sound absorption, and sound penetration within the panel. In this embodiment, the expanded perlite system is present in the substrate mat in an amount of from about 5% by weight to about 80% by weight, more preferably from about 10% by weight to about 60% by weight and most preferably about 20% by weight. Up to about 40% by weight, based on the weight of the board.

In a preferred embodiment, the substrate mat comprises a renewable component, mineral wool, expanded perlite, starch, calcium carbonate, and/or clay. A preferred renewable component is a ground rice husk. The percentage of renewable components is from about 0.1% to about 95% by weight, more preferably from about 5% to about 60% by weight and most preferably from about 7% to about 40% by weight, based on the weight of the board.

Another optional component of the sound absorbing panel is clay, which is typically included in the sound absorbing panel to improve fire resistance. When exposed to fire, the clay does not burn; instead, the clay will sinter. Optionally, the sound absorbing panel may comprise from about 0% to about 10% by weight clay, preferably from about 1% to about 5% by weight clay, based on the weight of the board. A variety of types of clay can be used including, but not limited to, Spinks Clay and Ball Clay from Gleason, TN. and Old Hickory Clay from Hickory, KY.

Optionally, a coagulant may be added to the sound absorbing panel. The coagulant is preferably used in an amount of from about 0.1% by weight to about 3% by weight, more preferably from about 0.1% by weight to about 2% by weight, based on the weight of the sheet. Useful coagulants include, but are not limited to, aluminum chlorohydrate, aluminum sulfate, calcium oxide, iron chloride, ferrous sulfate, polyacrylamide, sodium aluminate, and sodium citrate.

In an embodiment of the base pad for manufacturing a sound absorbing panel, an aqueous slurry is preferably obtained by using water and renewable components, mineral wool, expanded perlite, cellulose fibers, starch, calcium carbonate, clay, and The coagulant is prepared by mixing. The mixing operation is preferably carried out in a slurry tank and can be processed in batch mode or continuous mode. The amount of water added may be such that the total solids content or concentration obtained is from 1% to about 8% by weight, preferably from about 2% to about 6%, and more preferably from about 3% to about 5%. .

Once the homogeneous slurry containing one of the above components is formed, the slurry is transported to a headbox which provides a stable stream of slurry material. The slurry flowing out of the front end box is spread over the moving production line of the hole to form a wet base pad. Water is first discharged from the production line by gravity. It is contemplated that in certain embodiments, a low vacuum pressure may be used in combination or after draining water from the slurry by gravity. Additional water may then be removed as needed by squeezing and/or using vacuum assisted water removal, as will be appreciated by those of ordinary skill in the art. The remaining water is typically evaporated in an oven or kiln to form a formed substrate mat.

Once formed, the substrate mat preferably has a bulk density of from about 7 to about 30 pounds per cubic foot (112 to 480 kilograms per cubic meter), more preferably from about 8 to about 25 pounds per cubic foot (128 to 400 kilograms per inch). The bulk density of the cubic meter is preferably from about 9 to about 20 pounds per cubic foot (144 to 320 kilograms per cubic meter) of bulk density.

The formed substrate mat is then cut and converted into a sound absorbing panel by a processing trimming operation well known to those of ordinary skill in the art. Some preferred processing trimming operations (among others) include surface grinding, coating, perforating, texturing, edge finishing, and/or packaging.

Perforation and texturing can significantly improve the sound absorption value of the above substrate mat. The perforation operation provides a plurality of holes of controlled depth and density (the number of holes per unit area) on the surface of a substrate mat. The perforation can be accomplished by pressing a plate with a predetermined number of needles into a base pad. The texturing can, for example, provide a uniquely shaped indentation on a formed substrate mat with a cylinder equipped with a patterned metal sheet. Both the perforation and texturing steps open the surface of the substrate mat and its internal structure to allow air to enter and exit the panel. The opening in the base pad also allows sound to enter and be absorbed by the substrate core.

In addition, the sound absorbing panel can optionally be laminated with a scrim or screen. It is considered that the sound absorbing panel of the present invention can be manually cut by a utility knife.

Once formed, the sound absorbing panels of the present invention preferably have a bulk density of from about 9 to about 32 pounds per cubic foot (144 to 513 kilograms per cubic meter), more preferably from about 10 to about 27 pounds per cubic foot (160 to 160). The bulk density of 433 kg/m3 and, optimally, the bulk density of from about 11 to about 22 pounds per cubic foot (176 to 352 kilograms per cubic meter). Further, the plate preferably has a thickness of from about 0.2 吋 to 1.5 吋 (5 to 38 mm), more preferably from about 0.3 吋 to 1.0 吋 (8 to 25 mm), more preferably from about 0.5 吋 to about 0.75 吋. Thickness (13 to 19 mm).

The sound absorbing panel comprising at least one renewable component preferably has an NRC value of at least about 0.25 and a CAC value of at least about 25. Furthermore, the sound absorbing panel can have an eNRC value of at least about 0.15. In addition, the sound absorbing panel can have a MOR value of at least about 80 pounds per square inch (psi) and a hardness of at least about 100 pounds, and can reach 1.5 inches (38 mm) in a 90% RH wet air chamber. The maximum sag value. What is more, the sound absorbing panel can have a flame spread index of less than about 25 and an aerosol generation index of less than about 50. The sound absorbing panel also has an STC of at least about 25.

Example 1

The rice husk was obtained from Riceland Industries, Jonesborough, AR, where the coarse rice was milled to separate the rice from the rice husk. The rice husks were sorted according to sieve size, #6 mesh screen, #10 mesh screen (with 0.066 inch or 1.7 mm opening), #16 mesh screen (with 0.039 inch or 1 mm opening) and #30 mesh screen. The size distribution of the rice hulls contained about 18.3% on the #10 mesh, about 58.0% on the #16 mesh, about 20.1% on the #30 mesh, and about 3.6% through the #30 mesh. The bulk density of the rice husk is about 8.51 lbs/cu (30 kg/m3).

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and rice hulls as listed in Table 1. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground rice husk, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, the coagulant is added to the slurry at a concentration of about 0.1% by weight, based on the weight of the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then extruded to a fixed wet thickness to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a higher pressure vacuum (5 to 9 Torr (127 to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In the following examples, about 10% by weight of mineral wool, and about 19% by weight of newsprint fibers, about 8% by weight of starch, and about 6% by weight of calcium carbonate were used, based on the weight of the board. The amount of perlite and rice husk is as follows. The characteristics of the resulting dried base mat are also listed.

As shown in the table, the base mat having a higher weight percentage of rice husk also has a lower airflow resistance value, demonstrating that the base mat is more porous. Therefore, the base mat containing more rice husks is more audible, which can be reflected in the unperforated eNRC value.

Example 2

The rice husk is obtained from Riceland Industries, Jonesborough, AR, where the coarse rice is milled to separate the rice from its shell. The rice husks were further ground with a perforated sieve size Fritz mill equipped with a 0.109 inch (0.028 meter) diameter. The rice husks are ground until all the materials pass through the sieve. The additional rice husks were separated by grinding and using a sieve having 0.079 吋 (0.002 m) and 0.050 吋 (0.0013 m). Corresponding to the screen openings of 0.109 吋 (0.028 m), 0.079 吋 (0.002 m) and 0.050 吋 (0.0013 m), the bulk density of the above samples is about 14.62 lb/cu ft (234 kg/cubic). Ruler), 16.31 lbs/cub (261 kg/m3) and 21.77 lbs/cub (349 kg/m3).

A slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and rice hulls as listed in Table 2. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground rice husk, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, the coagulant is added to the slurry in an amount of about 0.1% by weight. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then extruded to a fixed wet thickness to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a higher pressure vacuum (5 to 9 Torr (127 to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 2, about 10% by weight of mineral wool, and about 19% by weight of newsprint fibers, about 8% by weight of starch, and about 6% by weight of calcium carbonate were used to form the panels, by weight of the panels. The amount of perlite and rice husk is as follows. The characteristics of the resulting dried base mat are also listed.

As shown in the table, a substrate mat having a rice hull that can pass through a larger screen opening is more audible, which can be reflected in higher eNRC values.

Example 3

The rice husk is obtained from Rice Hull Specialties, Stuttgart, AR, where the rice husk from the rice milling plant is ground. First, the ground rice hulls were sieved through a #20 mesh screen to remove larger particles, which were then sieved through a #80 mesh screen to remove smaller particles. The ground rice husk, which was passed through a #20 mesh screen and retained on a #80 mesh screen, was used to make a base mat. The bulk density is about 22.96 lbs/cub (368 kg/m3).

A slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and rice hulls as listed in Table 3. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground rice husk, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of coagulant was added to the slurry, based on the weight of the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then extruded to a fixed wet thickness to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a higher pressure vacuum (5 to 9 Torr (127 to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 3, panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and rice husk is as follows. The characteristics of the resulting dried base mat are also listed.

All three samples in the examples were significantly more porous and more audible than the control groups of Test Nos. 1 and 2 in Example 1.

Example 4

The rice husk is obtained from Rice Hull Specialties, Stuttgart, AR, where the rice husk from the rice milling plant is ground. First, the ground rice hulls were sieved through a #30 mesh screen to remove larger particles, which were then sieved through a #80 mesh screen to remove smaller particles. The ground rice husk, which was passed through a #30 mesh screen and retained on a #80 mesh screen, was used to make a base mat. The bulk density is about 28.56 lbs/cub (457 kg/m3). In a slurry tank, a slurry is prepared by mixing water and a plate component according to the composition of Table 4:

In addition to the components of Table 4, an additional 20% by weight of recycled sound absorbing panels (or "fragments") were added, based on the weight of the panels. Recycling sound absorbing panels are defective products, substandard quality products or polished finished boards. The recycled sound absorbing panels can be of the same or different composition.

The concentration of the slurry was about 3.0%. A homogeneous slurry containing the components of Table 4 is delivered to the front end tank which provides a stable stream of slurry material. The slurry flowing from the front end tank is then spread over a production line of holes to form a wet substrate mat. Water is first discharged from the production line by gravity. Additional water is removed by applying a low vacuum pressure (4 Torr (100 mm Hg)) below the line. After pressing the substrate mat between the two rolls, additional water is removed by applying a relatively high vacuum pressure (7 to 15 Torr (178 to 381 mm Hg)) below the line. The remaining water and moisture in the wet substrate pad are evaporated in a kiln.

After drying, the substrate mats are cut, ground, rolled and spray coated, pricked and textured to become a visually pleasing sound absorbing panel, which can be 2 呎 x 4 呎 (0.61 metric x 1.22 metric metre). ) or 2呎×2呎 (0.61 meters × 0.61 meters). The base pad characteristics series are shown in Table 5:

In addition, Table 6 shows the characteristics of the processed sound-absorbing panels:

Example 5

The rice husk is obtained from Rice Hull Specialties, Stuttgart, AR, where the rice husk from the rice milling plant is ground. First, the ground rice hulls were sieved through a #20 mesh screen to remove larger particles, which were then sieved through a #80 mesh screen to remove smaller particles. The ground rice husk, which was passed through a #20 mesh screen and retained on a #80 mesh screen, was used to make a base mat. The bulk density is about 24.73 lbs/cub (390 kg/m3). In a slurry tank, a slurry is prepared by mixing water and a plate component according to the composition of Table 7:

In addition to the components of Table 4, an additional 15% by weight (by weight of the board) of the split board was added.

The concentration of the slurry was about 3.0%. A homogeneous slurry containing the components of Table 7 is delivered to the front end tank which provides a stable stream of slurry material. The slurry flowing from the front end tank is then spread over a production line of holes to form a wet substrate mat. Water is first discharged from the production line by gravity. Additional water is removed by applying a low vacuum pressure (1 Torr (25 mm Hg)) below the line. After the base mat is squeezed between the two rolls, additional water is removed by applying a relatively high vacuum pressure (5 to 9 Torr (127 to 229 mm Hg)) below the line. The remaining water and moisture in the wet substrate pad are evaporated in a kiln.

After drying, the substrate mats are cut, ground, rolled and spray coated, pricked and textured to become a visually pleasing sound absorbing panel, which can be 2 呎 x 4 呎 (0.61 metric x 1.22 metric metre). ) or 2呎×2呎 (0.61 meters × 0.61 meters). The base pad characteristics series are listed in Table 8:

In addition, Table 9 shows the characteristics of the processed sound-absorbing panels:

Example 6

Buckwheat shells are available from Zafu Store, Houston, TX. The buckwheat hulls were further ground in a Fritz mill equipped with a perforated sieve size of 0.05 inch (1.27 mm) diameter. The buckwheat husk is ground until all the materials pass through the sieve. The milled buckwheat hull has a bulk density of about 24.5 lbs/cm (392 kg/m3). The size distribution of the ground buckwheat hulls was as follows: 21.0% was retained on #20 mesh, 47.4% was retained on #30 mesh, 21.0% was retained on #40 mesh, and 5.6% was retained on #50 mesh 2.8% was retained on the #100 mesh screen and 2.3% passed the #100 mesh screen.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and buckwheat hulls as listed in Table 10. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground buckwheat hulls, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of the coagulant was added to the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then squeezed to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a higher pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 10, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amounts of perlite and buckwheat hulls are as follows. The characteristics of the resulting dried base mat are also listed.

As shown in the table, the base mat containing the buckwheat hull is more audible, which can be indicated by an eNRC value higher than the control group (Test No. 1).

Example 7

Wood shaving, which is a pine bedding, is available from American Wood Fiber Inc., Columbia, MD. The wood flakes were further ground in a Fritz mill equipped with a perforated sieve size of 0.050 inch (1.27 mm) diameter. Grind the wood flakes until all the materials have passed through the sieve. The milled wood flakes have a bulk density of about 8.9 pounds per cubic foot (143 kilograms per cubic meter). The size distribution of the ground wood flakes is as follows: 5.5% is retained on #20 mesh, 37.6% is retained on #30 mesh, 24.3% is retained on #40 mesh, and 13.6% is retained on #50 mesh. 12.6% remained on the #100 mesh screen and 6.4% passed the #100 mesh sieve.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and wood flakes as listed in Table 11. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground wood flakes, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of coagulant was added to the slurry, based on the weight of the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then extruded to a fixed wet thickness to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a higher pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 11, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and wood shavings is as follows. The characteristics of the resulting dried base mat are also listed.

As shown in the table, the base mat containing the ground wood flakes is more audible, as indicated by the higher eNRC value than the control set (Test No. 1).

Example 8

Wheat straw is available from Galusha Farm in Warrenville, IL. The wheat straw was further ground in a Fritz mill equipped with a perforated sieve size of 0.050 inch (1.27 mm) diameter. Grind the wheat straw until all the materials have passed through the sieve. The milled wheat straw has a bulk density of about 7.7 pounds per cubic foot (123 kilograms per cubic meter). The size distribution of the ground wheat straw was as follows: 3.6% retained on the #20 mesh sieve, 25.3% retained on the #30 mesh sieve, 25.4% retained on the #40 mesh sieve, and 19.8% retained on the #50 mesh sieve. 17.1% remained on the #100 mesh screen and 8.9% passed the #100 mesh screen.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and wheat straw as listed in Table 12. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground wheat, mineral wool and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of coagulant was added to the slurry, based on the weight of the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then extruded to a fixed wet thickness to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a higher pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 12, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amounts of perlite and wheat are as follows. The characteristics of the resulting dried base mat are also listed.

As shown in the table, the base mat containing the wood flakes is more audible, as evidenced by an eNRC value higher than the control group (Test No. 1).

Example 9

The saw dust from the floor sweeping material was obtained from ZEP, Carterville, GA. The sawdust density of the sawdust is about 24.0 lbs/cub (384 kg/m3). The size distribution of sawdust is as follows: 9.0% is retained on #20 mesh, 24.3% is retained on #30 mesh, 22.7% is retained on #40 mesh, and 19.1% is retained on #50 mesh, 21.4% Retained on the #100 mesh screen and 3.6% through the #100 mesh screen.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and sawdust as listed in Table 13. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, sawdust, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of the coagulant was added to the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then squeezed to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a high pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 13, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and sawdust is as follows. The resulting dried base pad characteristics are also listed.

As shown in the table, the base mat containing sawdust is more audible, as evidenced by an eNRC value higher than the control group (Test No. 1).

Example 10

The ground corn cob was obtained from Kramer Industries Inc., Piscataway, NJ. The milled corn cob has a bulk density of about 18.5 pounds per cubic foot (296 kilograms per cubic meter). The size distribution of the ground corn cob is as follows: 0.0% is retained on #20 mesh, 0.1% is retained on #30 mesh, 1.6% is retained on #40 mesh, and 94.1% is retained on #50 mesh 4.1% remained on the #100 mesh screen and 0.2% passed the #100 mesh screen.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and ground corn cobs as listed in Table 14. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground corn cob, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of the coagulant was added to the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then squeezed to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a high pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 14, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and corn cob is as follows. The resulting dried base pad characteristics are also listed.

As shown in the table, the base mat containing the ground corn cob is more sound absorbing, as evidenced by an eNRC value higher than the control group (Test No. 1).

Example 11

The ground walnut shell was obtained from Kramer Industries Inc., Piscataway, NJ. The milled walnut shell has a bulk density of about 44.2 lbs/cub (708 kg/m3). The size distribution of the ground walnut shell is as follows: 0.0% is retained on #20 mesh, 0.0% is retained on #30 mesh, 3.9% is retained on #40 mesh, and 72.5% is retained on #50 mesh 23.2% remained on the #100 mesh screen and 0.3% passed the #100 mesh screen.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and walnut shells as listed in Table 15. In the case where the water is continuously stirred, components are added in the following order: news pulp, starch, calcium carbonate, ground walnut shell, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of the coagulant was added to the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then squeezed to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a high pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 15, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and walnut shell is as follows. The resulting dried base pad characteristics are also listed.

As shown in the table, the base mat containing the ground walnut shell is more audible, as evidenced by a higher eNRC value than the control group (Test No. 1).

Example 12

Peanut shells are obtained from a local grocery store. The peanut shell was further ground in a Fritz mill equipped with a perforated sieve size of 0.05 inch (1.27 mm) diameter. The peanut shell is ground until all the materials pass through the sieve. The milled peanut shell has a bulk density of about 15.2 pounds per cubic foot (243 kilograms per cubic meter). The size distribution of the ground peanut shell is as follows: 0.2% is retained on the #20 mesh, 13.1% is retained on the #30 mesh, 31.5% is retained on the #40 mesh, and 19.8% is retained on the #50 mesh. 29.2% remained on the #100 mesh screen and 6.1% passed the #100 mesh screen.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and varying amounts of perlite and peanut shells as listed in Table 16. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground peanut shell, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of the coagulant was added to the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then squeezed to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a high pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 16, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and peanut shell is as follows. The resulting dried base pad characteristics are also listed.

As shown in the table, the base mat containing the ground peanut shell is more audible, as evidenced by an eNRC value higher than the control group (Test No. 1).

Example 13

Sunflower seed shells were obtained from Archer Deniels Midland, ND. The milled sunflower seed shell has a bulk density of about 12.4 pounds per cubic foot (199 kg/m 3 ). The size distribution of the ground sunflower seed shell is as follows: 0.1% is retained on #20 mesh, 8.9% is retained on #30 mesh, 30.3% is retained on #40 mesh, and 29.3% is retained in #50 mesh Up, 23.9% remained on the #100 mesh screen, and 7.5% passed the #100 mesh sieve.

The slurry having a concentration of about 4.5% was formed by mixing water with the plate components and different amounts of perlite and ground sunflower seed hulls as listed in Table 17. In the case where the water is continuously stirred, the components are added in the following order: news pulp, starch, calcium carbonate, ground sunflower seed shell, mineral wool, and expanded perlite. The slurry was agitated for about 2 minutes. At the end of the agitation, about 0.1% by weight of the coagulant was added to the slurry. The slurry was then poured into a forming box measuring 14 吋 x 14 吋 x 30 吋 (0.36 ft x 0.36 ft x 0.76 metre).

At the bottom of the forming box, the fiberglass scrim supported by a metal mesh allows the slurry water to be freely discharged while retaining most of the solids. Additional water can be removed by applying a low pressure vacuum (1 Torr (25 mm Hg)) to the forming box. The wet substrate pad is then squeezed to remove additional water and also strengthen the substrate pad structure. Finally, the wet substrate pad further removes water by applying a high pressure vacuum (5 to 9 Torr (127 mm Hg to 229 mm Hg)). The formed panels were then dried in an oven or kiln at 315 ° C (600 ° F) for 30 minutes and at 149 ° C (300 ° F) for 3 hours to remove any remaining moisture.

In Table 17, the panels were formed using about 10% by weight mineral wool, and about 19% by weight newsprint fibers, about 8% by weight starch, and about 6% by weight calcium carbonate, based on the weight of the panels. The amount of perlite and sunflower seed shell is as follows. The resulting dried base pad characteristics are also listed.

As shown in the table, the base mat containing the ground sunflower seed shell is more sound absorbing, as evidenced by an eNRC value higher than the control group (Test No. 1).

Although the invention has been shown and described herein as a particular embodiment of a board containing a renewable component as a building material, it will be appreciated that those skilled in the art can change or modify the invention without departing from the invention. The scope is as defined in the attached patent application.

Claims (15)

A board for use as a building material, the board being formed from an aqueous slurry comprising an inorganic fiber component, starch, water, and a renewable component, after removing water, the sheet is about 0.1% by weight to About 95% by weight of the renewable component; wherein the panel has at least one of: a Ceiling Attenuation Class value (CAC) value of at least about 25, and a Noise Reduction Coefficient of at least about 0.25. The NRC) value, and a Sound Transmission Class (STC) value of at least about 25. The panel of claim 1 wherein the renewable component comprises rice hulls. The board of claim 1 having an estimated noise reduction coefficient (eNRC) value of at least about 0.20. The panel of claim 1 having a gas flow resistance of less than 8 millipascals per square meter (mPa ̇s/m ² ). The panel of claim 1 having a Modulus of Rupture (MOR) value of at least about 80 pounds per square inch (psi). The panel of claim 1 having a bulk density of from about 7 pounds per cubic foot (lbs/ft ³ ) to about 30 pounds per cubic foot (lbs/ft ³ ). The sheet of claim 1 having a thickness of from about 0.2 吋 to about 1.5 。. The panel of claim 1 having a lower sag value of less than about 1.5 Torr in a 90% RH wet air chamber. The panel of claim 1 having a flame spread index of less than about 25. The panel of claim 1 having an aerosol generation index of less than about 50. The panel of claim 1 wherein the renewable component comprises less than about 5% by weight of particles retained in a mesh screen having an opening of about 0.312 inches. The panel of claim 1 wherein the renewable component comprises less than about 5% by weight of the particles retained in a mesh having an opening of about 0.132 inches. The panel of claim 1 wherein the renewable component comprises less than about 5% by weight of the particles retained in a mesh having an opening of about 0.022 inches. The panel of claim 1 wherein the bulk density of the renewable component is from 5 to 50 pounds per cubic foot (lbs/ft ³ ). A board for use as a building material, the board being formed from an aqueous slurry comprising an inorganic fiber component, starch, water, and a renewable component, after removing water, the sheet is about 0.1% by weight to About 95% by weight of the renewable component is reduced in size such that no more than 5% by weight of the renewable component remains in a mesh having an opening of about 0.312 inches; wherein the plate has the following At least one of: a ceiling attenuation rating value of at least about 25, a noise reduction factor value of at least about 0.25, and a sound penetration rating value of at least about 25.