Patent ID: 12220895

DETAILED DESCRIPTION OF THE INVENTION

The ensuing description provides exemplary embodiments only, and is not intended to limit the scope, applicability, or configuration of the disclosure. Rather, the ensuing description of the exemplary embodiments will provide those skilled in the art with an enabling description for implementing one or more exemplary embodiments. It being understood that various changes may be made in the function and arrangement of elements without departing from the spirit and scope of the invention as set forth in the appended claims.

Fiber Mat Facer

The embodiments below disclose fiber mat facers that may be coupled with constructions boards, such as ceiling panels, drywall boards, polyisocyanurate foam boards, etc. to provide an aesthetically appealing look. The fiber mat facers discussed below include multiple layers of glass fibers made in a single step or process. In other words, the layers of the facers discussed below are not separately formed and then combined in a later stage or process (i.e., separately made and then bonded together). Rather, the layers are formed simultaneously, which results in a facer that functions as a single layer in terms of structure and integrity despite having different fiber compositions and layer densities. Accordingly, the facers discussed may be produced at lower cost and in less time.

In addition to including multiple layers, the facers discussed below may include a coating. The coating may be aesthetic or add desired properties to the construction board. For example, the coating may provide a flat, gloss-free surface. The coating may also enable a non-directional visual appearance, meaning that the appearance does not depend on the angle in which the fiber mat facer is viewed. In some embodiments, the coating may be a fire retardant coating, water repellent coating, washable coating, impact-resistant coating, scratch-resistant coating, soil resistant coating, or a combination thereof.

One or more of the layers may include a blend of differently sized glass fibers. The differently sized glass fibers form layers of different densities within the facer. For example, one or more layers may include both coarse and microfibers. Furthermore, some embodiments may include one or more layers of differently sized coarse fibers, differently sized microfibers, or a combination thereof. The coarse or larger diameter fibers may range in size between about 8 and about 25 μm, and small diameter fibers or microfibers may range in size between about 0.5 and 6 μm. In a more specific embodiment, the coarse or larger diameter fibers may range in size between about 8 and about 16 μm, and more commonly between about 11 and 16 μm. The small diameter fibers or microfibers may range in size between about 1 and 6 μm, and more commonly between 2 and 4 μm.

By including layers with different densities, the non-woven fiber mat facilitates bonding between the core material and the facer by absorbing the core material of the construction board. Simultaneously, the more dense layer of the non-woven fiber mat (e.g., layer with microfibers) blocks the core material of the construction material from passing through (e.g., bleeding through) the facer. Thus, the non-woven fiber mat may form a construction board that is aesthetically pleasing and uniform in appearance. Conventional facers often employ a coating on the exterior surface that prevents bleed through of the core material and/or that masks any bleed through of the core material that occurs. The facers described herein are able to prevent bleed through of the core material without requiring the use of a coating on the exterior surface of the facer. Further, a coating on the exterior surface is not needed since bleed through of the core material will not be present or visible on the exterior surface of the facer.

In a specific embodiment, the larger diameter fibers may be about 13 μm diameter fibers and the microfibers may be about 3 μm in diameter. The facer includes at least one binder that bonds the large diameter fibers and microfibers together to form the fiber mat. The binder may be water repellant and/or include a water repellant additive such as a stearylated melamine water repellant.

FIG.1is a cross-sectional view of a construction board10with a facer12(e.g., glass facer) and a core material14. The core material14may be gypsum, magnesium oxide, polyisocyanurate, polystyrene, etc. As illustrated, the facer12includes multiple layers (e.g., 1, 2, 3, 4, 5, or more). These layers are formed in a single process, that is the layers are not produced in separate processes and then later combined. InFIG.1, the facer12includes a first layer16and a second layer18. The first layer16is a non-woven glass fiber mat formed using coarse fibers20. The term “coarse fibers” in this application is understood to mean glass fibers having an average diameter between about 8 and 25 μm and an average length between about ¼ inch and 2 inches. While the first layer16includes coarse fibers20, the second layer18typically includes microfibers22. The term “microfibers” is understood to mean glass fibers having an average diameter between about 0.5 and 6 μm with varying length. The coarse and microfibers may be fibers made from E glass, C glass, T glass, sodium borosilicate glass, A & S glasses, Basalt, mineral wool, slag fiber, and mixtures thereof.

In some embodiments, the second layer18may be formed solely out of microfibers22. In another embodiment, the second layer18may be formed out of a combination of coarse fibers20and microfibers22. When a combination of coarse fibers and microfibers are employed, the coarse fibers and microfibers are typically homogenously dispersed or distributed throughout the second layer18. In an embodiment that includes both coarse fibers20and microfibers22, the percentage of weight of the coarse fibers20and the microfibers22may vary. For example, the percentage by weight of the coarse fibers20in the second layer18may vary between 60 and 99 percent, while the percentage by weight of the microfibers22may vary between 1 and 40 percent. In another embodiment, the percentage by weight of the coarse fibers20in the second layer18may vary between 1 and 20 percent, while the percentage by weight of the microfibers22may vary between 80 and 99 percent, which would result in a mat that is substantially less porous. The coarse fibers20in the second layer18provide strength and integrity to the layer.

In another embodiment, the second layer18may be formed entirely of microfibers22having an average fiber diameter of between 0.5 and 6 μm. The second layer18may be formed from a single, relatively uniform, microfiber size or the second layer18may be formed from a combination of differently sized microfibers22, which are typically homogenously dispersed or distributed throughout the second layer18. For example, the second layer18may be formed from a first type of microfibers22having an average diameter between 0.5 and 1 μm, which is then mixed with a second type of microfibers22having an average diameter between 3 and 6 μm. The weight percentages of the first and second types of microfibers22may vary in the second layer18. For example, the percentage by weight of the first type of microfiber22may vary between 5 and 50 percent while the second type of microfiber22may vary between 50 and 95 percent. The percentages of the first and second types of microfibers may be varied depending on an aesthetic attribute of the resulting layer18. For example, if the layer18needs to be smooth, the layer18will contain a higher percentage of the first type of microfibers22having average diameters between 0.5 and 1 μm. If the purpose of the layer18is mainly to block the core material from passing through to the external surface, the layer18could include a blend of the first and second types of microfibers that is closure to a 50-50 blend.

In one embodiment, the first layer16may be formed entirely of coarse fibers20having an average fiber diameter of between 8 and 25 μm, between 8 and 16 μm, and more commonly between 11 and 16 μm. In another embodiment, the first layer16may include both coarse fibers20and microfibers22, which are typically homogenously dispersed or distributed throughout the first layer16. For example, the percentage by weight of the coarse fibers20in the first layer16may vary between 75 and 99 percent, while the percentage by weight of the microfibers22may vary between 1 and 25 percent. In another embodiment, the first layer16may be formed from a combination of differently sized coarse fibers20, which are typically homogenously dispersed or distributed throughout the first layer16. For example, the first layer16may be formed from a first type of coarse fibers20having an average diameter between 8 and 11 μm, which is then mixed with a second type of coarse fibers20having a diameter between 12 and 25 μm.

The facer12includes a binder that binds the respective fibers together in the first layer16and in the second layer18and that also bonds the first layer16and the second layer18together. In one embodiment, the facer12includes a single binder that functions to both bind the fibers together in the respective layers and bond the respective layers together. The binder is typically homogenously or relatively evenly dispersed or distributed throughout the facer12. Stated differently, the binder may be distributed homogenously within the first layer16and the second layer18and may also be homogenously distributed through the first and second layers16,18. Since the binder is relatively evenly distributed through the facer12in this manner, the facer12does not include a separate binder, or a layer of binder, at an interface between the first layer16and the second layer18. Stated differently, there is not a concentration of a binder at an interface or boundary between the first and second layers16,18since the binder is evenly distributed through the facer12. This even distribution of the binder results from the formation of the first and second layers16,18in a single step. In addition, the fibers of the first and second layers16,18are more integrated, intertwined, and intermeshed with one another at the interface or boundary of the layers due to the formation of the layers in a single step. This results in more gradual transition between the first and second layers16,18.

In some embodiments, the facer12may have a combined thickness26between about 0.1 and 1.5 mm. In some embodiments, the thickness of the facer12may be less than 20 percent of an overall thickness of the core14. Although the facer12is illustrated on only a single side or face of the core14, it should be realized that in other embodiments, the facer12may be positioned on both sides or faces of the core14. In such instances, the first layer16is typically positioned directly adjacent the core14while the second layer18is positioned atop the first layer16as illustrated inFIG.1.

As explained above, the facer12includes first and second layers16,18with different densities. The differences in densities may facilitate coupling of the facer12to the core material14while also block the core material14from passing through (i.e., bleeding through) the facer12. The first and second layers have respective thicknesses30,32. For example, the thickness30of the first layer16may be between 0.1 and 1 mm, and the thickness32of the second layer18may be between 0.1 and 0.5 mm. Each of these layers16,18may also be defined as a percentage of the overall facer thickness26. For example, the first layer16may be between 30 and 95 percent of the overall facer thickness26, and the second layer18may be between 5 and 50 percent of the overall facer thickness26. To prevent bleed through of the core material14, the density of the second layer18may be proportional to the thickness of the second layer18. For example, if the second layer18is more dense then the layer18may be thinner while still be effective to prevent bleed through. If the second layer18is too dense, however, the second layer18may not be open or porous enough to release moisture during curing, which might pose downstream issue during manufacturing of the board. The second layer18may be less dense when the layer18is a little thicker. The combination of the less dense and thicker board may still be effective to prevent bleed through. The combination of density and thickness described herein provides a good balance that is effective to prevent bleed through without causing manufacturing difficulties.

The thickness30of the first layer16may be greater than the thickness32of the second layer18because the first layer16may include more coarse fibers20. Furthermore, because the first layer16includes coarse fibers20the density of the first layer16may be less than the second layer18. The use of the coarse fibers20in the first layer16may render the first layer16more porous than the second layer18. For example, the first layer16may have a Frasier air permeability of greater than or equal to 500 cubic feet per minute (cfm) when measured against a pressure drop of 0.5 in of water. The second layer18may have a Frasier air permeability of less than or equal to 300 cfm when measured according to the same standard. The less dense first layer16enables the first layer16to absorb the core material14when the facer12is applied as a facer to the core material14during manufacturing of the construction board10. Specifically, the core material14may be relatively wet or unhardened and may absorb or penetrate into the first layer16due to the porosity of the first layer16. The penetration or absorption of the core material14into the first layer16may bind the core material14to the facer12during manufacturing. However, because the second layer18includes microfibers22the second layer18is more dense than the first layer16; the second layer18may therefore block the core material14from passing through the facer12when the facer12is applied as a facer to the core material14during manufacture of the construction board10. The use of a significant amount of microfibers22in the second layer18renders the second layer18significantly less porous than the first layer16, which blocks or prevents the core material14from bleeding through the second layer18to an exterior surface of the facer12where it would be visible. The inclusion of a significant amount of microfibers22in the second layer18allows the second layer18to exhibit a Frasier air permeability of less than or equal to 300 cfm. As illustrated, the core material14may absorb fully through the first layer16and partially through the second layer18. The use of the microfibers22, however, prevents bleed through of the core material14to the exterior surface of the facer12. In this way, the facer12is able to form a uniform aesthetically pleasing appearance of the construction board10while absorbing the core material14to bond the facer to the core material14.

FIG.2is a cross-sectional view of a construction board50. The construction board50includes a facer12coupled to a core material14. The core material14may similarly be gypsum, magnesium oxide, polyisocyanurate, polystyrene, etc. As illustrated, the facer12includes multiple layers (e.g., 1, 2, 3, 4, 5, or more) formed in a single process. The facer12includes a first layer16, a second layer18, and a coating52. The first layer16is a non-woven glass fiber mat formed using one or more types of coarse fibers. As explained above, the term “coarse fibers” in this application is understood to mean glass fibers having an average diameter between about 8 and 25 μm and an average length between about ¼ inch and 2 inches. The second layer18includes one or more types of microfibers and in some embodiments may include a combination of microfibers and coarse fibers. The term “microfibers” is understood to mean glass fibers having an average diameter between about 0.5 and 6 μm with varying length. The coarse and microfibers may be fibers made from E glass, C glass, T glass, sodium borosilicate glass, A & S glasses, Basalt, mineral wool, slag fiber, and mixtures thereof.

In some embodiments, the second layer18may be formed solely out of microfibers22. In another embodiment, the second layer18may be formed out of a combination of coarse fibers20and microfibers22, which are typically homogenously dispersed or distributed throughout the second layer18. The percentage by weight of the coarse fibers20in the second layer18may vary between 60 and 99 percent, while the percentage by weight of the microfibers22may vary between 1 and 40 percent. In another embodiment, the percentage by weight of the coarse fibers20in the second layer18may vary between 1 and 20 percent, while the percentage by weight of the microfibers22may vary between 80 and 99 percent, which would result in a mat that is substantially less porous. The coarse fibers20in the second layer18provide strength and integrity to the layer.

In another embodiment, the second layer18may be formed from a combination of differently sized microfibers22, which are typically homogenously dispersed or distributed throughout the second layer18. For example, the second layer18may be formed from a first type of microfibers22having an average diameter between 0.5 and 1 μm, which is then mixed with a second type of microfibers22having an average diameter between 3 and 6 μm. The weight percentages of the first and second types of microfibers22may also vary in the second layer18. For example, the percentage by weight of the first type of microfiber22may vary between 5 and 50 percent while the second type of microfiber22may vary between 50 and 95 percent. The percentages of the first and second types of microfibers may be varied depending on an aesthetic attribute of the resulting layer18. For example, if the layer18needs to be smooth, the layer18will contain a higher percentage of the first type of microfibers22having average diameters between 0.5 and 1 μm. If the purpose of the layer18is mainly to block the core material from passing through to the external surface, the layer18could include a blend of the first and second types of microfibers that is closure to a 50-50 blend.

The first layer16may also include both coarse fibers20and microfibers22, which are typically homogenously dispersed or distributed throughout the first layer16. For example, the percentage by weight of the coarse fibers20in the first layer16may vary between 75 and 99 percent, while the percentage by weight of the microfibers22may vary between 1 and 25 percent. In another embodiment, the first layer16may be formed from a combination of differently sized coarse fibers20, which are typically homogenously dispersed or distributed throughout the first layer16. For example, the first layer16may be formed from a first type of coarse fibers20having average diameters between 8 and 11 μm, which is then mixed with a second type of coarse fibers20having average diameters between 12 and 25 μm. The weight percentages of the first and second types of coarse fibers20may also vary in the first layer16. For example, the percentage by weight of the first type of coarse fibers may vary between 50 and 95 percent while the second type of coarse fibers may vary between 5 and 50 percent.

The facer12includes a binder that binds the respective fibers together in the first layer16and in the second layer18and that also bonds the first layer16and the second layer18together. In one embodiment, the facer12includes a single binder that functions to both bind the fibers together in the respective layers and bond the respective layers together. The binder is typically homogenously or relatively evenly dispersed or distributed throughout the facer12. Stated differently, the binder may be distributed homogenously within the first layer16and the second layer18and may also be homogenously distributed through the first and second layers16,18. Since the binder is relatively evenly distributed through the facer12in this manner, the facer12does not include a separate binder, or a layer of binder, at an interface between the first layer16and the second layer18. Stated differently, there is not a concentration of a binder at an interface or boundary between the first and second layers16,18since the binder is evenly distributed through the facer12. This even distribution of the binder results from the formation of the first and second layers16,18in a single step. In addition, the fibers of the first and second layers16,18are more integrated, intertwined, and intermeshed with one another at the interface or boundary of the layers due to the formation of the layers in a single step. This results in more gradual transition between the first and second layers16,18.

As explained above, the construction board50includes a facer12with the coating52. The coating52is applied to the second layer18to supplement or add additional properties to the first and second non-woven glass layers16and18. For example, the coating52may be a fire retardant coating, water repellent coating, washable coating, impact-resistant coating, scratch-resistant coating, soil resistant coating, or a combination thereof. In some embodiments, the coating52may be simply for aesthetic purposes. In some embodiments, the coating52may be a binder based material that is configured to remain atop the facer12rather than penetrate through the facer to bind the first and second layers,16and18, together. The binder of the coating52may be a modified urea-formaldehyde binder that includes a filler, such as mica. The inclusion of the mica may enable the binder to remain atop the facer12and thereby form the coating52. The binder may adhere the coating52to the top surface of the facer12. The coating may include other materials as described herein, such as Aluminum Trihydrate (ATH), calcium carbonate, clay, vermiculite, wollastonite etc. or a combination of these.

In some embodiments, the facer12and coating52may have a combined thickness26between about 0.1 and 1.5 mm. In some embodiments, the thickness of the facer12may be less than 20 percent of an overall thickness of the core14. Although the facer12is illustrated on only a single side or face of the core14, it should be realized that in other embodiments, the facer12may be positioned on both sides or faces of the core14. In such instances, the first layer16is typically positioned directly adjacent the core14while the second layer18is positioned atop the first layer16as illustrated inFIG.2. A coating52may be applied atop the second layer18.

As explained above, the facer12includes first and second layers16,18with respective thicknesses30,32. The thickness30of the first layer16may be between 0.1 and 1 mm, and the thickness32of the second layer18may be between 0.1 and 0.5 mm. The coating52also defines a thickness54, which is typically less than or equal to about 0.2 mm. Each of these layers16,18, and52may also be defined as a percentage of the overall facer thickness26. For example, the first layer16may be between 30 and 95 percent of the overall facer thickness26, the second layer18may be between 5 and 50 percent of the overall facer thickness26, and the coating52may be less than 15 percent of the overall facer thickness26. To prevent bleed through of the core material14, the density of the second layer18may be proportional to the thickness of the second layer18. For example, if the second layer18is more dense then the layer18may be thinner while still be effective to prevent bleed through. If the second layer18is too dense, however, the second layer18may not be open or porous enough to release moisture during curing, which might pose downstream issue during manufacturing of the board. The second layer18may be less dense when the layer18is a little thicker. The combination of the less dense and thicker board may still be effective to prevent bleed through. The combination of density and thickness described herein provides a good balance that is effective to prevent bleed through without causing manufacturing difficulties.

The thickness30of the first layer16may be greater than the thickness32of the second layer18because the first layer16may include more coarse fibers20. Furthermore, because the first layer16includes coarse fibers20the density of the first layer16may be less than the second layer18. The first layer16may be significantly more porous than the second layer18. For example, the first layer16may have a Frasier air permeability of greater than or equal to 500 cubic feet per minute (cfm) when measured against a pressure drop of 0.5 in of water. The second layer18may have a Frasier air permeability of less than or equal to 300 cfm when measured according to the same standard. The less dense first layer16enables the first layer16to absorb and bind the core material14to the facer12during manufacturing. However, because the second layer18includes microfibers22the second layer18is more dense and less porous than the first layer16; the second layer18is therefore able to block the core material14from passing through the facer12. Similarly, the density of the second layer18may absorb but also block the coating52from passing through second layer18. By blocking the flow of coating52through the second layer18, the second layer18may reduce the use of coating52on the facer12while still forming a uniform and aesthetically appealing construction board50. As illustrated, the core material14may absorb fully through the first layer16and partially through the second layer18. The use of the microfibers22, however, prevents bleed through of the core material14to the exterior surface of the facer50. The inclusion of a significant amount of microfibers22in the second layer18allows the second layer18to exhibit an air permeability of less than or equal to 300 cfm.

Exemplary facers are described in the Table 1 below. In both examples, the top layer (i.e., second layer18) includes a combination of coarse fiber (¾″ K117 fibers) and microfiber (110X-481). The top layer includes approximately 90% coarse fibers and 10% microfibers. In both examples, the bottom layer (i.e., second layer18) includes a combination of coarse fiber (¾″ K117 fibers) and microfiber (110X-481). In the first example, the binder is a modified urea-formaldehyde (UF) binder. A filler material (i.e., mica) was added to the binder and the binder was added to the mat to bond the fibers of the two layers together. The binder was added so that the facer exhibited a loss on ignition of approximately 29%. The mica that was added to the binder formed a coating (i.e., coating52) atop the facer. In addition to adhering the fibers together, the binder also adhered the filler particles (mica) together and adhered the coating layer to the facer.

Example 2 is similar to example 1 with the primary difference being the type of filler material that was employed. In example 2, the filler material is Aluminum Trihydrate (ATH). The filler material (ATH) formed a layer atop the facer due to the filler material being filter out by the second layer. In some instances, the air permeability may be controlled by the amount and type of filler particles that are added to the binder. The binder was added so that the facer exhibited a loss on ignition of approximately 27-28%. The properties of both facers were roughly the same with the exception of the air permeability, which was significantly less in the facer of example 1 due to the coating of the mica. The air permeability in example 1 was significantly less despite the facers having a roughly equivalent mean pore size.

TABLE 1Exemplary facersGlass &MeanBasisGlassFillerFillerAirPoreWeightWTWTWTPermSizeFiberBinder(lbs/ft2)LOI %(lbs/ft2)(lbs/ft2)(lbs/ft2)(cfm)(μm)Example 1Top layer:Arclin UF +2.8429.11.72.070.371397490% ¾″ K117Rhoplex& 10% 110X-481GL-720 &Bottom Layer:Mica100% ¾″ K117Example 2Top Layer:Arclin UF +3.027.51.662.150.492727490% ¾″ K117Rhoplex GL& 10% 110x-481720 & ATHBottom Layer:100% ¾″ K117

Table 2 below provides additional exemplary mats or facers in comparison with conventional facers that are used for construction boards. The first conventional mat (i.e., labeled “Mat 1” in Table 2) is a combination of ¾ inch Johns Manville K117 glass fibers and Johns Manville 110X-481 microglass fibers. The porosity of Mat 1 is in the mid-range, which may be attributed to the addition of microfiber. Table 3 demonstrates that Mat 1 has a high propensity to absorb water (i.e., 292% absorption), which might not be desirable for certain applications. The absorption percentage indicated in Table 3 is the weight of water absorbed by the glass mat as a percentage of the mat weight. It may be possible to reduce the water absorption by adding a coating layer to Mat 1, however, for certain applications the addition of a coating may render Mat 1 too closed off (indicated by low air perm of 280) to allow the core material to penetrate into the mat, which would result in a weak bond between the core material and Mat 1.

The other conventional mat (i.e., labeled “Mat 2” in Table 2) is modified to alleviate some of the issues associated with bonding the facer to the core. However, Mat 2 is too open or porous as demonstrated by the high air permeability and thus, Mat 2 suffers from the core material bleeding through the mat to the exterior surface of the facer. A coating layer typically cannot be applied to Mat 2 as described herein due in part to the high air permeability since the high porosity of the mat will allow the coating to penetrate into and throughout the mat, which will close off the pores. The closed pores prevent the core material from penetrating into the mat, which would result in a weak bond between the core material and the facer. For such a mat, a coating layer has to be applied as a secondary and separate step, which is a time consuming, complicated, and costly process.

In some instances, conventional Mat 1 can be combined with conventional Mat 2 to form a dual layer. However, this combination has to be performed in a second step by application of a binder/adhesive at the interface of the two mats. The application of the adhesive at the interface results in a concentration of binding material at the interface of the two layers and further results in two distinct layers—i.e., one layer containing the coarse fiber and microfiber and the other layer being solely coarse fiber.

Example 1 in Table 2 is a dual layer structure where top layer consists of ¾ inch Johns Manville K117 glass fiber and Johns Manville 110X-481 glass microfiber. The bottom layer is 100 percent ¾ inch Johns Manville K117 glass fibers. Both layers are formed simultaneously as described herein and thus, the resulting mat is free of a concentrated adhesive layer between the two layers. The binder is modified UF, which binds the fibers and the two layers together. Mica was added to the binder which forms a top coating layer. The bottom layer is open and has an air permeability similar to Mat 2 (i.e., 617 cfm), which allows the core material to penetrate into the bottom layer and form a good bond. The top layer has an air permeability similar to Mat 1 (i.e., 280), which prevents bleed through of the core material. The mica coating on top can provide additional smoothness to the facer for handling, for reducing water absorption, for reducing air permeability and/or porosity, etc. Example 1 may have a total air permeability of about 139 cfm.

Example 2 in Table 2 is constructed similar to that of Example 1, except that ATH was added to the binder instead of Mica. Example 2 demonstrates that different raw materials can be used as a coating layer. Table 3 shows a comparison of the mat produced in Example 2 and Mat 1 and specifically shows a significant reduction in water absorption that is achieved via the mat of Example 2—i.e., 3.70 percent in comparison with 292 percent for Mat 1.

Example 3 in Table 2 is constructed similar to that of Examples 1 and 2. The binder used in Example 3 is an acrylic binder modified with UF, which demonstrates that various examples of binders can be used to construct the multi-layered mats described herein. No filler was added to the binder used in constructing the mat of Example 3. The single binder is the only component that is used to bond or adhere the fibers in the two layers and to bond or adhere the two layers together.

In all three examples, the binder is uniformly or homogenously distributed throughout the top and bottom layers and there is no binder concentration at the interface. In addition, because the two layers were formed simultaneously, a small gradient of microfibers exists at the interface, which enhances the physical bond or entanglement of the fibers of the top and bottom layers. Specifically, a portion of the microfibers of the second layer18at or near the interface migrate into the first layer16and vice versa. The degree of migration of the fibers and the resulting physical bond or entanglement is unique to the mats formed in accordance with the disclosure herein since such entanglement and migration is not achievable without simultaneously forming the layers. The migration of the fibers is a desirable feature since it makes the interface between the layers gradual, which allows the core material to partially penetrate into the second layer18. The migration of the fibers also forms a strong bond between the layers.

TABLE 2Exemplary facers in comparison with conventional facersGlassOverallBasisGlass& FillerFillerAirWeightWTWTWTPermFiberBinder(lbs/ft2)LOI %(lbs/ft2)(lbs/ft2)(lbs/ft2)(cfm)Example 1Top layer: 90% ¾″Arclin UF +2.8529.11.72.070.37139K117 & 10% 110X-481Dow AcrylicBottom Layer: 100%& Mica¾″ K117Example 2Top layer: 90% ¾″Arclin UF +3.0027.51.662.150.49272K117 & 10% 110X-481Dow AcrylicBottom Layer: 100%& ATH¾″ K117Example 3Top Layer: 90% ¾″Lubrizol2.4028.51.721.720110K117 & 10% 110X-481StyreneBottom Layer: 100%Acylic +¾″ K117Arclin UFMat 1 typically used as facer90% ¾″ K117 & 10%Arclin UF +2.2527.01.641.640280110x-481Dow AcrylicMat 2 typically used as facer¾″ K 117Arclin UF +2.1020.01.681.680617Dow Acrylic

Table 3 shows a comparison between conventional Mat 1 and the mat of Example 2 in Table 2 above.

TABLE 3Comparison of conventional Mat 1 and Example mat 2 of Table 2FiberBinderAbsorptionMat 190% ¾″ K117 &Arclin UF +292%10% 110x-481Dow AcrylicExample 2Top layer: 90% ¾″Arclin UF +3.70%K117 & 10% 110X-481Dow Acrylic &Bottom Layer:ATH100% ¾″ K117
Fiber Mat Forming System

FIG.3is a schematic view of a manufacturing system68that produces a facer12. In operation, the manufacturing system68is able to produce a multilayered facer in a single step/process. That is the layers of the facer are not separately formed and then combined at a later stage or process (i.e., separately made and then bonded together). The facers12produced by the manufacturing system68may therefore be produced at lower cost and in less time.

The manufacturing system68includes multiple fluid lines that deliver coarse fibers and microfibers to a hydroformer70that simultaneously forms the first and second layers16,18of the facer12. While a hydroformer70is illustrated, a fourdinier wire or a delta former may also be used to produce first and second layers16,18of the facer12in a single step/process.

The manufacturing system68produces the first layer16using a first fluid line72that delivers coarse fiber to the hydroformer. The first fluid line72includes at least one coarse fiber source74containing one or more types of coarse fibers (e.g., differently sized coarse fibers, coarse fibers made from different materials, or a combination thereof). Fluidly coupled to the coarse fiber source74is a pump76(e.g., a thick stock pump) that pumps a first fluid77containing the coarse fibers. For example, the first fluid77may include water, viscosity modifiers, dispersants, defoamers, etc. mixed with the coarse fibers. After passing through the pump76, the first fluid77is diluted with a dilution fluid78(e.g., water, viscosity modifiers, dispersants, defoamers, or a combination thereof) stored in a dilution tank80. By diluting the coarse fibers, the manufacturing system68may enable a more even distribution of the coarse fibers in the first layer16by the hydroformer. The dilution fluid80combines with the first fluid77before the first fluid77enters a second pump82. The pump82(e.g., thin stock pump) may facilitate mixing of the first fluid77and the dilution fluid80before delivery to the hydroformer70. After exiting the pump82, the first fluid77enters a first inlet pipe84of the hydroformer70. The first inlet pipe84directs the first fluid77into the hydroformer70, which forms the first layer of the facer12by removing the first fluid77and dilution fluid80from the fluid/coarse fiber mixture as the mixture is poured onto the hydroformer70.

In order to form the second layer18of the facer12, the manufacturing system68includes a second fluid line86. The second fluid line86includes at least one coarse fiber source74containing one or more types of coarse fibers (e.g., differently sized coarse fibers, coarse fibers made from different materials, or a combination thereof). Fluidly coupled to the coarse fiber source74is a pump88(e.g., a thick stock pump) that pumps a second fluid89containing the coarse fibers. For example, the second fluid89may include water, viscosity modifiers, dispersants, defoamers, etc. mixed with the coarse fibers. After passing through the pump88, the second fluid89is diluted with a dilution fluid90(e.g., water, viscosity modifiers, dispersants, defoamers, or a combination thereof) stored in a dilution tank92. By diluting the second fluid89, the manufacturing system68may enable even distribution of the fibers in the second layer18. The dilution fluid90combines with the second fluid89before the second fluid89enters a second pump94. The pump94(e.g., thin stock pump) enables mixing of the second fluid89and the dilution fluid90before delivery to the hydroformer70. After exiting the pump94, the second fluid89enters a second inlet pipe96of the hydroformer70. The second inlet pipe96directs the second fluid89into the hydroformer70, which forms the second layer18of the facer12by removing the second fluid89and dilution fluid90from the fluid/fiber mixture as the mixture is poured onto the hydroformer70atop the first layer of the facer12that was immediately formed by the hydroformer. The second fluid89is directed or poured atop the first layer of the facer12as the fluid is being drained from the first fluid77such that the second layer18and the first layer16are formed simultaneously by the hydroformer.

Fluidly coupled to both the first and second fluid lines72,86is a third fluid line98. The third fluid line98includes at least one microfiber source100containing one or more types of microfibers (e.g., differently sized microfibers, microfibers made from different materials, or a combination thereof). Fluidly coupled to the microfiber source100is a pump102(e.g., a stock pump) that pumps a third fluid103containing the microfibers. The third fluid103may include water, viscosity modifiers, dispersants, defoamers, etc. mixed with the microfibers. After passing through the pump102, the third fluid103may be pumped into the first and/or second fluid lines72,86. In this way, microfibers may be mixed with coarse fibers to increase the density of either the first and/or second layers16,18. As illustrated, the third fluid line98couples upstream from the pumps76and88. By coupling upstream from the pumps76and88, the manufacturing system68uses the turbulent flow through the pumps76and88to facilitate mixing of the third fluid103with the first and/or second fluids77,89. However, in some embodiments, the third fluid line98may couple to the first and second fluid lines72,86downstream from the pumps76and88. For example, the manufacturing system68may rely on the pumps82and94to mix the third fluid103with the first or second fluids77,89. In still other embodiments, the third fluid line98may couple upstream as well as downstream of the pumps76and88. This layout may enable the gradual introduction of the third fluid into the first and/or second fluid lines at different locations.

The flow of the first, second, and third fluids77,89,103through the manufacturing system68may be controlled with a controller104. The controller104may include one or more processors106that execute instructions stored on one or more memories108to control the operation of various valves as well as the pumps. For example, the third fluid line98may include first and second valves110,112. As illustrated, the first valve110controls the flow of the third fluid into the first fluid line72, while the second valve112controls the flow of the third fluid into the second fluid line86. By controlling the first and second valves110,112the controller104is able to control the amount of the third fluid combining with the first and/or second fluids77,89. This in turn controls the amount of microfibers in the first and second layers16,18produced in the hydroformer70. In this way, the manufacturing system68may vary the microfiber content in the first and second layers16,18to between 0 and 100 percent, and more commonly to the percentages described in the facer embodiments herein.

The manufacturing system68may also control the fluid flow through the first and second fluid lines72,86using additional valves114and116as well as controlling the pumps76,82,88,94, and102. By controlling the flow of the first and second fluids77,89the controller104may increase or decrease thickness of the respective first and second layers16,18. Stated differently, the manufacturing system68may increase or decrease the thickness of the first and/or second layers16,18of the facer12depending on the type of desired facer12. For example, the manufacturing system68may increase the flow of the first fluid77through the fluid line72to increase the thickness of the first layer16and decrease the flow of the second fluid89to decrease the thickness of the second layer18. Similarly, the manufacturing system68may decrease the flow of the first fluid77through the fluid line72to decrease the thickness of the first layer16and increase the flow of the second fluid89to increase the thickness of the second layer18.

As the first and second fluids77,89enter the hydroformer70they contact a conveyer belt117that drains a substantially majority of the fluid in the first and second fluids77,89leaving behind the combined first and second layers16,18. The manufacturing system68may then apply one or more binders118. In some embodiments, the binder118may include additives, such as flame resistant resinous binders such as urea formaldehyde, modified urea formaldehyde, acrylic resins, modified acrylic resins, polyurethanes, polyvinyl chlorides, melamine resins, homopolymers or copolymers of polyacrylic acid; crosslinking acrylic copolymers; crosslinked vinyl chloride acrylate copolymers (e.g., copolymers having a GTT of about 113° C. or less), among other types of binders. Flame retardants may also be included in the binder, such as Alumina trihydrate, organic phosphonates, Antimony oxide, and the like.

These binders118may be stored in one or more binder sources120. The binder(s)118may be applied to the first and second layers16,18by moving the first and second layers16,18under a spray or waterfall of binder. Any excess binder may then flow through the first and second layers. In this way, the manufacturing system68may bind the fibers in their respective layers as well as bind the layers16,18together without performing multiple binding steps/processes. Stated differently, the manufacturing system68may simultaneously bind the fibers in the respective layers and bond the fibers layers together in a single step. The application of the binder(s)118to the first and second layers16,18simultaneously results in the binder being relatively evenly distributed through and between the first and second layers16,18without forming or defining a binder layer between the first and second layers16,18. Stated differently, a separate or individual layer of binder is not formed or defined at an interface or boundary between the first and second layers16,18as occurs in conventional systems where the layers are formed individually and combined in a subsequent process. The relatively even distribution of the binder(s)118may increase the strength of the facer and/or reduce issues such as delamination of the layers. In addition, the facer described herein has a less defined boundary between the first and second layers16,18since these layers are simultaneously formed. Rather, the facer has a relatively gradual transition from the first layer16to the second layer18due to the simultaneous formation of the layers, which may increase the strength and/or reduce issues such as delamination of the layers.

In some embodiments, the manufacturing system68may deposit a coating(s)122atop the second layer18after applying the binder118. The coating122may be stored in a coating source124(e.g., tank) and sprayed onto the facer12. In other embodiments, the coating may be formed via a filler material that is added to the binder and that is filtered out via the second layer18. For example, the filler material (e.g., mica) may be added to the binder and the binder may be applied to the facer12to bind the fibers together. Excess binder118may be removed from the facer12via an applied vacuum or via some other method. The second layer18, and in particular the microfibers, may act as a filter for the filler material (e.g., mica) during the binder application process. The filler material that is deposited on and remains atop the second layer18forms a coating layer122. The binder118adheres the filler particle to the second layer18, thereby adhering the coating122to the second layer18. In this embodiment, a second or additional step of applying the coating122separately is not needed. The coating122may be a fire retardant coating, water repellent coating, washable coating, impact-resistant coating, scratch-resistant coating, soil resistant coating, or a combination thereof.

FIG.4is a schematic view of a manufacturing system140that produces a facer12. In operation, the manufacturing system140is able to produce a multilayered facer in a single step/process. That is the layers16,18of the facer12are not separately formed and then combined at a later stage or process (i.e., separately made and then bonded together). The facers12produced by the manufacturing system140may therefore be produced at lower cost and in less time.

The manufacturing system140includes multiple fluid lines that deliver coarse fibers and microfibers to a hydroformer70that simultaneously forms the first and second layers16,18of the facer12. While a hydroformer70is illustrated, a fourdinier wire or delta former may also be used to produce first and second layers16,18of the facer12in a single step/process.

The manufacturing system140produces the first layer16using a first fluid line72that delivers coarse fiber to the hydroformer. The first fluid line72includes at least one coarse fiber source74containing one or more types of coarse fibers (e.g., differently sized coarse fibers, coarse fibers made from different materials, or a combination thereof). Fluidly coupled to the coarse fiber source74is a pump76(e.g., a thick stock pump) that pumps a first fluid77containing the coarse fibers. For example, the first fluid77may include water, viscosity modifiers, dispersants, defoamers, etc. mixed with the coarse fibers. After passing through the pump76, the first fluid77is diluted with a dilution fluid78(e.g., water, viscosity modifiers, dispersants, defoamers, or a combination thereof) stored in a dilution tank80. By diluting the coarse fibers, the manufacturing system140may enable even distribution of the coarse fibers in the first layer16by the hydroformer70. The dilution fluid80combines with the first fluid77before the first fluid77enters a second pump82. The pump82(e.g., thin stock pump) may facilitate mixing of the first fluid77and the dilution fluid80before delivery to the hydroformer70. After exiting the pump82, the first fluid77enters a first inlet pipe84of the hydroformer70. The first inlet pipe84directs the first fluid77into the hydroformer70, which forms the first layer of the facer12by removing the first fluid77and dilution fluid80from the fluid/fiber mixture as the mixture is poured onto the hydroformer70.

In order to form the second layer18of the facer12, the manufacturing system140includes a second fluid line86. The second fluid line86includes at least one coarse fiber source87containing one or more types of coarse fibers (e.g., differently sized coarse fibers, coarse fibers made from different materials, or a combination thereof). The coarse fibers in the coarse fiber source87may be the same as or different from the coarse fibers in the coarse fiber source74. In this way, the first and second fluid lines72and86may produce layers with different coarse fibers sizes and/or coarse fibers made from different materials. Fluidly coupled to the coarse fiber source74is a pump88(e.g., a thick stock pump) that pumps a second fluid89containing the coarse fibers. For example, the second fluid89may include water, viscosity modifiers, dispersants, defoamers, etc. mixed with the coarse fibers. After passing through the pump88, the second fluid89is diluted with a dilution fluid90(e.g., water, viscosity modifiers, dispersants, defoamers, or a combination thereof) stored in a dilution tank92. By diluting the second fluid89, the manufacturing system140may enable even distribution of the fibers in the second layer18. The dilution fluid90combines with the second fluid89before the second fluid89enters a second pump94. The pump94(e.g., thin stock pump) enables mixing of the second fluid89and the dilution fluid90before delivery to the hydroformer70. After exiting the pump94, the second fluid89enters a second inlet pipe96of the hydroformer70. The second inlet pipe96directs the second fluid89into the hydroformer70, which forms the second layer18of the facer12by removing the second fluid89and dilution fluid90from the fluid/fiber mixture as the mixture is poured onto the hydroformer70atop the first layer of the facer12that was immediately formed by the hydroformer. The second fluid89is directed or poured atop the first layer16of the facer12as the fluid is being drained from the first fluid77such that the second layer18and the first layer16are formed simultaneously by the hydroformer.

Fluidly coupled to both the first and second fluid lines is a third fluid line98. The third fluid line98includes at least one microfiber source100containing one or more types of microfibers (e.g., differently sized microfibers, microfibers made from different materials, or a combination thereof). Fluidly coupled to the microfiber source100is a pump102(e.g., a stock pump) that pumps a third fluid103containing the microfibers. The third fluid103may include water, viscosity modifiers, dispersants, defoamers, etc. mixed with the microfibers. After passing through the pump102, the third fluid103may be pumped into the first and/or second fluid lines72,86. In this way, microfibers may be mixed with coarse fibers to increase the density of either the first and/or second layers16,18. As illustrated, the third fluid line98couples upstream from the pumps76and88. By coupling upstream from the pumps76and88, the manufacturing system140uses the turbulent flow through the pumps76and88to facilitate mixing of the third fluid103with first and/or second fluids77,89. However, in some embodiments, the third fluid line98may couple to the first and second fluid lines72,86downstream from the pumps76and88. For example, the manufacturing system68may rely on the pumps82and94to mix the third fluid103with the first or second fluids77,89. In still other embodiments, the third fluid line98may couple upstream as well as downstream of the pumps76and88. This layout may enable the gradual introduction of the third fluid into the first and/or second fluid lines at different locations.

The flow of the first, second, and third fluids77,89,103through the manufacturing system140may be controlled with a controller104. The controller104may include one or more processors106that execute instructions stored on one or more memories108to control the operation of the valves as well as the pumps. For example, the third fluid line98may include first and second valves110,112. As illustrated, the first valve110controls the flow of the third fluid into the first fluid line72, while the second valve112controls the flow of the third fluid into the second fluid line86. By controlling the first and second valves110,112, the controller104is able to control the amount of the third fluid combining with the first and/or second fluids77,89. This in turn controls the amount of microfibers in the first and second layers16,18. Accordingly, the first and second layers16,18may vary in microfiber content including having no microfiber content.

The manufacturing system140may also control the fluid flow through the first and second fluid lines72,86by controlling the pumps76,82,88,94, and102. By controlling the flow of the first and second fluids77,89the controller104may increase or decrease thickness of the respective first and second layers16,18. That is the manufacturing system140may increase or decrease the thickness of the first and/or second layers16,18of the facer12depending on the desired facer12. For example, a specific application may call for a thicker facer12to absorb more core material during manufacturing of the construction board10.

As the first and second fluids77,89enter the hydroformer70they contact a conveyer belt117that drains a substantially majority of the first and second fluids77,79leaving behind the combined first and second layers16,18. The manufacturing system140may then apply one or more binders118. In some embodiments, the binder118may include additives, such as flame resistant resinous binders such as urea formaldehyde, modified urea formaldehyde, acrylic resins, modified acrylic resins, polyurethanes, polyvinyl chlorides, melamine resins, homopolymers or copolymers of polyacrylic acid; crosslinking acrylic copolymers (e.g., acrylic copolymers having a glass transition temperature (GTT) of at least about 25° C.); crosslinked vinyl chloride acrylate copolymers (e.g., copolymers having a GTT of about 113° C. or less), among other types of binders. Flame retardants may also be included in the binder, such as Alumina trihydrate, organic phosphonates, Antimony oxide, and the like.

These binders118may be stored in one or more binder sources120. The binder(s)118may be applied to the first and second layers16,18by moving the first and second layers16,18under a spray or waterfall of binder. Any excess binder118may then flow through the first and second layers. In this way, the manufacturing system140may bind the fibers in their respective layers as well as bond the layers16,18together without performing multiple binding steps/processes. Stated differently, the manufacturing system140may simultaneously bind the fibers in the respective layers and bond the fibers layers together in a single step. The application of the binder(s)118to the first and second layers16,18simultaneously results in the binder being relatively evenly distributed through and between the first and second layers16,18without forming or defining a binder layer between the first and second layers16,18. Stated differently, a separate or individual layer of binder is not formed or defined at an interface or boundary between the first and second layers16,18as occurs in conventional systems where the layers are formed individually and combined in a subsequent process. The relatively even distribution of the binder(s)118may increase the strength of the facer and/or reduce issues such as delamination of the layers. In addition, the facer has a less defined boundary between the first and second layers16,18since these layers are simultaneously formed. Rather, the facer has a relatively gradual transition from the first layer16to the second layer18due to the simultaneous formation of the layers, which may increase the strength and/or reduce issues such as delamination of the layers.

After applying the binder118, the manufacturing system140may deposit a coating(s)122on the second layer18. The coating122may be stored in a coating source124(e.g., tank) and sprayed onto the facer12. In other embodiments, the coating may be formed via a filler material that is added to the binder and that is filtered out via the second layer18. For example, the filler material (e.g., mica) may be added to the binder and the binder may be applied to the facer12to bind the fibers together. Excess binder118may be removed from the facer12via an applied vacuum or via some other method. The second layer18, and in particular the microfibers, may act as a filter for the filler material (e.g., mica) during the binder application process. The filler material that is deposited on and remains atop the second layer18forms a coating layer122. The binder118adheres the filler particle to the second layer18, thereby adhering the coating122to the second layer18. In this embodiment, a second or additional step of applying the coating122separately is not needed. The coating122may be a fire retardant coating, water repellent coating, washable coating, impact-resistant coating, scratch-resistant coating, soil resistant coating, or a combination thereof.

For convenience in describing the various embodiments herein, the fibers were referred to a glass fibers—i.e., coarse glass fibers, microfibers, and the like. It should be realized that various other fiber types may be used in any of the embodiments described herein and that the embodiments are not limited solely to glass fibers unless otherwise specified in the claims. It should also be realized that the use of non-glass fibers are contemplated as being used in any of the embodiments. The non-glass fibers may be used in combination with glass fibers or instead of glass fibers. Accordingly, unless otherwise explicitly specified in the claims, the concepts and embodiments described herein may include only glass fibers, only non-glass fibers, or any combination of glass and non-glass fibers. Exemplary non-glass fibers include polymer fibers, synthetic fibers, organic fibers, inorganic fibers, natural fibers, and the like. Similarly, it should be understood that the glass microfibers and/or glass coarse fibers described herein can be partially or completely replaced with polymeric, synthetic, or natural microfibers. Thus, the general term “fibers”, “coarse fibers”, and/or “microfibers” may be used in the claims with such usage being understood to cover a variety of fibers including glass fibers and non-glass fibers. The terms “coarse fibers” and “microfibers” will be understood in relation to size to have the definitions provided herein.

Exemplary Methods

Referring now toFIG.5, illustrated is a method500of forming a fiber mat. In a specific embodiment, the fiber mat may be a glass facer for a construction board. At block502, a first fluid mixture is poured or applied onto a porous belt or surface. The first fluid mixture includes a first group of fibers that are homogenously mixed or dispersed within a first fluid. In a specific embodiment, the first group of fibers comprise or consist of coarse glass fibers having an average fiber diameter of between 8 μm and 25 μm. In other embodiments, the first group of fibers comprise or consist of a combination of coarse fibers and microfibers as described herein. When the first fluid mixture is applied or poured atop the porous belt or surface, the first fluid is drained or removed from the first fluid mixture so that a layer of the first group of fibers is formed atop the porous belt or surface. In some embodiments a vacuum may be applied to the porous belt or surface to facilitate in removal of the first fluid from the first fluid mixture.

At block504, a second fluid mixture is poured or applied onto the porous belt or surface atop the layer of the first group of fibers. The second fluid mixture includes a second group of fibers that are homogenously mixed or dispersed within a second fluid. In a specific embodiment, the second group of fibers comprise or consist of a combination of coarse glass fibers having an average fiber diameter of between 8 μm and 25 μm and glass microfibers having an average fiber diameter of between 0.5 μm and 6 μm. The amount of each fiber type may be similar to the embodiments described herein. In another embodiment, the second group of fibers comprises or consists entirely of glass microfibers having an average fiber diameter of between 0.5 μm and 6 μm.

When the second fluid mixture is applied or poured atop the porous belt or surface, the second fluid is drained or removed from the second fluid mixture so that a layer of the second group of fibers is formed atop the porous belt or surface and atop the layer of the first group of fibers. The second fluid mixture is poured or applied onto the porous belt or surface as the first fluid is being removed from the first fluid mixture. As such, the layer of the first group of fibers is typically not fully formed or defined until after the second fluid mixture is poured or applied onto the porous belt or surface. In this manner, the layer of the first group of fibers and the layer of the second group of fibers are formed simultaneously atop the porous belt or surface. The second fluid mixture may be poured directly vertically above the first fluid layer and thus, both layers may be poured simultaneously atop each other. Stated differently, since the layer of the first group of fibers is not fully formed or defined until after the second fluid mixture is poured or applied onto the porous belt or surface, the layer of the first group of fibers is formed or defined at essentially the same time as the layer of the second group of fibers is formed or defined atop of the porous belt or surface. Since the layer of the first group of fibers and the layer of the second group of fibers are formed simultaneously, the degree of intermeshing or entangling of the fibers at the interface of the two layers is significantly greater than in conventional fiber mats where one or both of the layers are fully formed or defined prior to application of the other layer. In some embodiments, the second fluid mixture may be poured or applied onto the porous belt or surface within 30 inches of where the first fluid mixture is poured or applied onto the porous belt or surface. In such instances, the fiber mat forming section (i.e., porous belt) may be extremely long such that the first layer is still dewatering when the second fluid mixture is applied to the belt. In other instances, the second layer may be poured within 12 inches or within 6 inches after the first layer is poured or applied to the porous belt. In such instances, the first layer may be partially dewatered, but still in the process of forming on the porous belt. In some embodiments, the second layer18(e.g., a more dense layer) may be poured atop the porous belt first and then the first layer16(e.g., a less dense layer) may be poured atop the second layer18. In such instances, a more dense layer may be formed on the bottom while a less dense layer is simultaneously formed on the top.

At block506, a binder is simultaneously applied to the layer of the first group of fibers and the layer of the second group of fibers in order to bind the two layers together and to bind the various fibers within each layer together. In most embodiments, a binder is not applied to either layer prior to block506, or stated differently, the layers are typically free of a binder prior to block506. The simultaneous application of the binder to the two layers, which are typically free of a binder prior to block506, results in a more homogenous or uniform distribution of the binder throughout the fiber mat. In addition, the simultaneous application of the binder to the two layer results in the fiber mat being free of a concentrated binder layer at the interface of the two layers. Conventional fiber mats typically include a binder concentration at the interface between layers because the fiber layers are formed separately and then adhered or bonded together via an additional binder. The additional binder bonds the two layers together and is typically concentrated at the interface between the two layers. In contrast, the process described herein is able for form a multiple layer fiber mat construction in which the binder is relatively homogenously or uniformly dispersed throughout the mat rather than being concentrated in one or more areas. In additional, a single binder may be employed to both bond or adhere the layers together and bond or adhere the fibers of the various layers together. Conventional mats commonly require the use of multiple binders in order to bond the fibers of the separate layers together and to subsequently bond the layers together.

At block508, a coating may optionally be applied atop the layer of the second group of fibers. The coating may be applied via a process that is separate from the application of the binder or the coating may be formed during the binder application process. For example, the binder may include a component (e.g., mica) that is filtered out by the layer of the second group of fibers as the binder is applied to this layer. The component that is filtered out may remain atop or on the exterior surface of the layer of the second group of fibers and form the coating. In such embodiment, the applied binder may bond or adhere the coating to the layer of the second group of fibers. In other embodiments, a separate coating may be applied to the layer of the second group of fibers subsequent to the application of the binder. In such embodiments, the applied binder may bond or adhere the coating to the layer of the second group of fibers or an additional binder may be used to bond or adhere the coating to the layer of the second group of fibers. The coating may be a water resistant coating, a fire-resistant coating, and an abuse-resistant coating, and the like.

In a specific embodiment, the fiber mat that is formed according to the method500ofFIG.5may be a facer for a construction board. In such embodiments, the facer may be applied to the construction board during formation of the construction board. The layer of the first group of fibers may be capable of absorbing a material of the construction board when the facer is positioned atop the construction board during formation of the construction board. The layer of the second group of fibers may partially absorb the material of the construction board, but may block the material from passing or absorbing through the facer to an exterior surface of the second layer. In this manner, the facer may be adhered or bonded with the construction board due to the absorption of the construction board material within the facer, but the material may not be visible on the exterior surface and, therefore, the visual appeal of the facer may be improved. The ability of the facer to block the construction board material from passing or absorbing through the facer to an exterior surface of the second layer is enabled without the use of a coating on the exterior surface of the second layer. As such, a coating is not required to visibly conceal the construction board's material from view, although a coating may be applied to add further visual appeal to the facer as desired. The ability of the second layer to block the construction board's material from passing or absorbing through the facer is due to the decreased porosity or air permeability of the second layer in comparison with the first layer as described herein.

It should be noted that while the method500ofFIG.5is described as simultaneously forming two layers, the method500could be employed to simultaneously form three or more layers as described. For example, block504could be repeated with a third fluid mixture, a fourth fluid mixture, and the like to form additional layers atop the layer of the second group of fibers. The binder could then be simultaneously applied to each of the layers at block506as desired. Thus, the method500ofFIG.5is not limited to two layer constructions.

While several embodiments and arrangements of various components are described herein, it should be understood that the various components and/or combination of components described in the various embodiments may be modified, rearranged, changed, adjusted, and the like. For example, the arrangement of components in any of the described embodiments may be adjusted or rearranged and/or the various described components may be employed in any of the embodiments in which they are not currently described or employed. As such, it should be realized that the various embodiments are not limited to the specific arrangement and/or component structures described herein.

In addition, it is to be understood that any workable combination of the features and elements disclosed herein is also considered to be disclosed. Additionally, any time a feature is not discussed with regard in an embodiment in this disclosure, a person of skill in the art is hereby put on notice that some embodiments of the invention may implicitly and specifically exclude such features, thereby providing support for negative claim limitations.

Having described several embodiments, it will be recognized by those of skill in the art that various modifications, alternative constructions, and equivalents may be used without departing from the spirit of the invention. Additionally, a number of well-known processes and elements have not been described in order to avoid unnecessarily obscuring the present invention. Accordingly, the above description should not be taken as limiting the scope of the invention.

Where a range of values is provided, it is understood that each intervening value, to the tenth of the unit of the lower limit unless the context clearly dictates otherwise, between the upper and lower limits of that range is also specifically disclosed. Each smaller range between any stated value or intervening value in a stated range and any other stated or intervening value in that stated range is encompassed. The upper and lower limits of these smaller ranges may independently be included or excluded in the range, and each range where either, neither or both limits are included in the smaller ranges is also encompassed within the invention, subject to any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included.

As used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a process” includes a plurality of such processes and reference to “the device” includes reference to one or more devices and equivalents thereof known to those skilled in the art, and so forth.

Also, the words “comprise,” “comprising,” “include,” “including,” and “includes” when used in this specification and in the following claims are intended to specify the presence of stated features, integers, components, or steps, but they do not preclude the presence or addition of one or more other features, integers, components, steps, acts, or groups.