Patent Publication Number: US-11384541-B2

Title: Roofing material with a non-asphalt backing

Description:
RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/507,163, filed on Jul. 10, 2019, which is a division of U.S. patent application Ser. No. 15/898,864, filed on Feb. 19, 2018, now U.S. Pat. No. 10,370,852, which is a continuation of U.S. patent application Ser. No. 15/245,406, filed on Aug. 24, 2016, now U.S. Pat. No. 9,932,739, which claims priority to and any benefit of U.S. Provisional Application No. 62/208,936, filed on Aug. 24, 2015, the disclosures of which are incorporated herein by reference in their entireties. 
    
    
     FIELD OF INVENTION 
     The present invention relates generally to the field of roofing materials and more particularly to asphalt-based roofing materials with a substrate coating material applied to the completed substrate instead of some of the roofing asphalt. 
     BACKGROUND 
     Asphalt-based roofing materials, such as roofing shingles, are installed on the roofs of buildings to provide protection from the elements and to give the roof an aesthetically pleasing look. Typically, the roofing shingles are constructed on a completed substrate, such as, for example, a glass fiber mat. A roofing shingle is constructed by coating the completed substrate with asphalt such that the asphalt saturates the substrate and forms an asphalt layer on both the top face and bottom face of the substrate. A decorative/protective surface layer of granules are applied in the asphalt layer on the top face of the completed substrate and a coating of sand or other particulate material is adhered to the asphalt layer on the bottom face of the substrate. The weight of and the ability to control the weight of the shingle during manufacturing, the cost of manufacturing the shingle, and the performance characteristics of the shingle are significantly impacted by the amount of asphalt and surface layers applied to the substrate. 
     SUMMARY 
     The present disclosure includes exemplary embodiments of asphalt based roofing materials where a substrate coating material is applied to the completed substrate instead of some of the roofing asphalt. The roofing material includes a completed substrate having a top face and a bottom face. The roofing material includes an asphalt layer covering at least a portion of the top face, and a surface layer of granules adhered to the asphalt layer. During manufacturing of the roofing material, the bottom face of the completed substrate is coated with a non-roofing asphalt coating. As such, the bottom face of the substrate in the finished roofing shingle is asphalt-free or substantially asphalt-free. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate some embodiments disclosed herein, and together with the description, serve to explain principles of the embodiments disclosed herein. 
         FIG. 1  is a top view of a prior art shingle; 
         FIG. 2  is a bottom view of the shingle of  FIG. 1 ; 
         FIG. 3  is a side section view of the shingle of  FIG. 1 ; 
         FIG. 4  is a top view of an exemplary embodiment of a roofing shingle according to the present invention; 
         FIG. 5  is a bottom view of the shingle of  FIG. 4 ; 
         FIG. 6  is a side section view of the shingle of  FIG. 4 ; 
         FIG. 7  is a schematic view of an exemplary embodiment of a shingle manufacturing apparatus that applies non-asphalt coating to a substrate of the shingle of  FIG. 4 ; 
         FIG. 8  is a schematic view of another exemplary embodiment of a shingle manufacturing apparatus that applies non-asphalt coating to a substrate of the shingle of  FIG. 4 ; 
         FIG. 9  is a schematic view of another exemplary embodiment of a shingle manufacturing apparatus for manufacturing the shingle of  FIG. 4 ; 
         FIG. 10  is section view of another exemplary embodiment of a roofing shingle according to the present invention; 
         FIG. 11  is top view of another exemplary embodiment of a roofing shingle according to the present invention; 
         FIG. 12  is section view of the roofing shingle of  FIG. 11  taken along the line  12 - 12  of the roofing shingle shown in  FIG. 11 ; 
         FIG. 13  is section view of the roofing shingle of  FIG. 11  taken along the line  13 - 13  of the roofing shingle shown in  FIG. 11 ; and 
         FIG. 14  is section view of another exemplary embodiment of a roofing shingle according to the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     The present invention will now be described with occasional reference to the illustrated embodiments of the invention. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein, nor in any order of preference. Rather, these embodiments are provided so that this disclosure will be more thorough, and will convey the scope of the invention to those skilled in the art. 
     Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for describing particular embodiments only and is not intended to be limiting of the invention. As used in the description of the invention and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. 
     Unless otherwise indicated, all numbers expressing quantities of ingredients, properties such as molecular weight, reaction conditions, and so forth as used in the specification and claims are to be understood as being modified in all instances by the term “about.” Accordingly, unless otherwise indicated, the numerical properties set forth in the specification and claims are approximations that may vary depending on the desired properties sought to be obtained in embodiments of the present invention. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as possible. Any numerical values, however, inherently contain certain errors necessarily resulting from error found in their respective measurements. 
     As used in the description and the appended claims, the phrase “asphalt” is defined as any type of bituminous material suitable for use on a roofing material, such as asphalts, tars, pitches, or mixtures thereof. The asphalt may be either manufactured asphalt produced by refining petroleum or naturally occurring asphalt. The asphalt may include various additives and/or modifiers, such as inorganic fillers or mineral stabilizers, organic materials such as polymers, recycled streams, or ground tire rubber. Preferably, the asphalt contains asphalt and an inorganic filler or mineral stabilizer. 
     As used in the description of the invention and the appended claims, the term “longitudinal” or “longitudinally” is defined as parallel with the machine direction or substantially parallel with the machine direction. The terms “top” and “bottom”, when used regarding the roofing material, are in reference to the roofing material when installed on a roof. “Bottom” referring to the portion facing towards the roof deck and “top” referring to the portion facing away from the roof deck. 
     Asphalt-based roofing materials, such as asphalt shingles, are commonly used in roofing applications.  FIGS. 1-3  illustrate a typical prior art asphalt shingle  100  having a top surface  102  and a bottom surface  104 . The shingle  100  includes a substrate  106 , such as a fiberglass mat, that includes a top face  108  and a bottom face  110 . During manufacturing of the shingle, the completed substrate  106  is coated with hot, melted asphalt  112 . The asphalt  112  saturates the completed substrate  106  and forms a top asphalt layer  114  on the top face  108  of the substrate  106  and a bottom asphalt layer  116  on the bottom face  110  of the substrate. A layer of granules  118  covers the top asphalt layer  114  and a backing coating layer  120 , such as sand or mica, covers the bottom asphalt layer  116 . Often, a continuous or discontinuous bead of tab sealant  122 , such as a modified asphalt adhesive, may be applied to the front side or the back side of the shingle and extend longitudinally adjacent and parallel a leading edge  124 . In  FIG. 2 , the tab sealant is applied to the back side of the shingle and is configured to adhere to an underlying shingle when installed on a roof. 
     When shingles are stacked for packaging and storage, two shingles may be placed back-to-back with one shingle rotated 180 degrees. The back coating layer  120  is applied so that the bottom asphalt layer  116  does not adhere to the bottom asphalt layer of the adjacent shingle when the shingles are stacked. Placing the shingles back-to-back avoids the tab sealant  122  sticking to and damaging the granular layer  118  on the top asphalt layer  114  of the shingle  100 . Rotating the shingles 180 degrees avoids the tab sealant  122  adhering to the tab sealant on the adjacent shingle. 
     If desired, a continuous strip of release tape  126 , typically polyethylene terephthalate (PET) tape, may be adhered to the back side of the shingle  100  adjacent to and parallel to a trailing edge  128 . The release tape  126 , to which the sealant will not stick, is positioned such that it will be aligned with the tab sealant of an adjacent shingle when the shingles are stacked. In some cases, instead of being placed back-to-back when stacked for packaging and storage, shingles may be stacked face to back. In such a case, the release tape is applied to the top of the shingles and provides the same function of preventing the tab sealant from adhering to the adjacent shingle. 
       FIGS. 4-6  illustrate an exemplary embodiment of a shingle  400  according to the present disclosure. The general inventive concepts, however, are not limited to shingles and could be readily extended to other asphalt-based roofing materials. The shingle  400  is generally planar and includes a top surface  402  and a bottom surface  404 . The shingle  400  includes a substrate  406  having a top face  408  and a bottom face  410  generally parallel to the top face. The substrate  406  may be any material suitable for use in asphalt-based roofing materials. Suitable materials may include, but not be limited to, a fiberglass mat, a scrim or felt of fibrous materials such as mineral fibers, cellulose fibers, rag fibers, mixtures of mineral and synthetic fibers, or the like. In the exemplary embodiment, the substrate  406  is a non-woven web of glass fibers. 
     In the example illustrated by  FIGS. 4-6 , a substitute coating material is applied to the completed substrate instead of some of the roofing asphalt of the shingle  400 . The non-asphalt coating  412  may include a variety of substances and additives. Any coating that enables the completed substrate  406  to function as a reinforcing member as well or better than when the completed substrate  406  is coated with roofing asphalt may be used. In the example illustrated by  FIG. 6 , the coating  412  is substituted for the asphalt on the bottom face  410  of the substrate  406 . In some cases, the coating  412  also substitutes for the asphalt in the mat, so there is less asphalt impregnation of the mat, little asphalt impregnation of the mat, or no asphalt impregnation of the mat. The coating  412  may be configured to improve one or more properties of the shingle  400 . For example, the non-asphalt coating  412  may improve, but not be limited to improving, the shingle&#39;s tear resistance, tensile strength, shingle stiffness, nail pull resistance, wind resistance, fire/burn resistance, cold curling resistance, masking ability (i.e. the ability of the shingle to mask imperfections in the roofing deck), and water shedding ability (in the package and on the roof). Suitable substances or additives for use in the non-asphalt coating  412  may include, but not be limited to, one or more of a filler, such as calcium carbonate, viscosity modifiers, dispersants, biocides, acrylic resins, clays, wollastonite, water repellants, or powdered resins such as powdered polyvinyl chloride (PVC), polypropylene, polyethylene, binders, such as latex binders, toners or colorants, and non-roofing asphalt. 
     In one exemplary embodiment, the coating  412  consists essentially of calcium carbonate, dispersant, latex binder, colorant, viscosity modifier, and/or biocide. In one exemplary embodiment, the coating  412  includes 90-96% calcium carbonate, 0-0.5% dispersant, 4-8% latex binder, 0-3% colorant, 0-0.5% viscosity modifier, and 0-0.25% biocide. In one exemplary embodiment, the coating  412  includes 91.5-92% calcium carbonate, 0.1-0.2% dispersant, 6-7.5% latex binder, 0.5-1.5% colorant, 0.1-0.2% viscosity modifier, and 0.05-0.15% biocide. In one exemplary embodiment, the coating  412  includes 93-95% calcium carbonate, 0.05-0.15% dispersant, 5.5-6.5% latex binder, 0-0.5% colorant, 0.05-0.15% viscosity modifier, and 0-0.05% biocide. In one exemplary embodiment, the coating  412  includes about 92% calcium carbonate, about 0.15% dispersant, about 7% latex binder, about 1% colorant, about 0.15% viscosity modifier, and about 0.1% biocide. In one exemplary embodiment, the coating  412  includes about 94% calcium carbonate, about 0.1% dispersant, about 6% latex binder, and about 0.1% viscosity modifier. 
     The coating  412  can be applied to impregnate the previously completed substrate  406  fully, partially, or not at all and thereby be substituted for all, some, or none of the asphalt that is applied to the top surface  408 . In this context, impregnation and substitution of roofing asphalt refer to filling the void or space between the fibers in the completed substrate  406 . For example, in the exemplary embodiment, the substrate  406  is a fiberglass mat. A completed, uncoated, non-woven fiberglass mat is essentially a web of glass fibers held together by a cured binder, but the majority of the space taken up by the completed fiberglass mat is air. Fully impregnating the completed mat or completely substituting a coating for the roofing asphalt in the mat means that all of the air space or substantially all of the air space, such as for example greater than 95% of the air space, between the glass fibers is filled with the coating while partially impregnating the mat or partially substituting a coating for the roofing asphalt in the mat with a coating means that some of the air space, such as for example less than 95% of the air space, between the glass fibers is filled. 
     The coating  412  can also be applied to substitute for the asphalt in the substrate  406  such that a discrete coating layer is formed on the top face  408 , on the bottom face  410 , or on both the faces. Depending on the application, the coating may be substituted for the roofing asphalt such that the shingle  400  may (i) have non-asphalt coating that impregnates the substrate and also forms a discrete layer on one or both faces, (ii) have a discrete non-asphalt coating layer on one face but the non-asphalt coating does not impregnate the substrate, (iii) have non-asphalt coating that impregnates the substrate but no discrete non-asphalt coating layer forms on either the top face or the bottom face, (iv) or have some other combination of impregnation/coating substitution and discrete layers. 
     In the shingle illustrated by  FIGS. 4-6 , at least a portion of the bottom face  410  of the substrate  406  is coated with non-asphalt coating  412  such that the non-asphalt coating forms a discrete bottom layer  414  on the bottom face  410  and partially impregnates the substrate  406 . As such, coating  412  is substituted for the roofing asphalt on the bottom  410  and coating  412  is substituted for a portion of the roofing asphalt that penetrates the mat. In addition, in the embodiments illustrated by  FIGS. 4-6 , at least a portion of the top face  408  of the substrate  406  is coated with asphalt  416  such that the asphalt forms a discrete top asphalt layer  418  on the top face  408  and also partially impregnates the substrate  406 . In one exemplary embodiment, all of the bottom face  410  is coated with non-asphalt coating  412  and all of the top face  408  is coated with asphalt  416 . In another exemplary embodiment, substantially all, such as for example greater than 95%, of the bottom face  410  is coated with non-asphalt coating  412  and substantially all, such as for example greater than 95% of the top face  408  of the substrate  406  is coated with asphalt  416 . The combination of the non-asphalt coating  412  impregnating the substrate  406  and the asphalt  416  impregnating the substrate results in the substrate being fully impregnated, or substantially fully impregnated. The bottom face  410  of the substrate  406 , however, is asphalt-free, or substantially asphalt-free. 
     The shingle  400  includes a layer of granules  420  that covers, and may be partially embedded into, the top asphalt layer  418 . The layer of granules  420  may be configured to include a variety of materials, shapes, colors, and sizes. Any granules suitable for use on the top face of an asphalt-based roofing shingle may be used. The shingle  400  does not include a coating of asphalt on the bottom face  410 . The absence of an asphalt coating on the bottom face  410  may decrease the chance of the shingle sticking to an adjacent shingle when the shingles are packaged for transport and storage. In addition, the need for a backing coating of sand or mica may be eliminated. 
     The completed substrate  406  may be formed by any suitable process, many of which are already known in the art. For example, in the exemplary embodiment, the fiberglass substrate  406  may be formed by a wet-laid process, as is known in the art. Generally, a wet-laid process involves adding glass fibers to a dispersant medium to form an aqueous slurry. Any suitable dispersant may be used. The dispersant, along with mechanical agitation, disperses the fibers sufficiently throughout the slurry. A continuous fine mesh screen passes through the fiber slurry such that the fibers are randomly deposited onto the screen to form a continuous non-woven web. Any excess liquid may be removed by vacuum or other suitable manner. The non-woven web is then saturated with a binder solution. Any suitable thermosetting or thermoplastic binder may be used, such as for example, traditional phenolic-formaldehyde binders, as well as the more recent formaldehyde-free binders, including polyacrylic binders and carbohydrate, starch or bio-based binders. The binder-saturated web then passes through an oven that is heated to a suitable temperature to cure the binder and form the complete dry fiberglass substrate  406 . 
     The completed substrate, in this case a standard completed fiberglass roofing mat, is used to manufacture an asphalt roofing shingle. The non-asphalt coating  412  that is substituted for the asphalt of the shingle may be applied to the completed substrate  406  in any suitable manner, which may vary depending on the desired outcome and the type of non-asphalt coating being applied.  FIG. 7  shows an exemplary embodiment of a shingle manufacturing apparatus  700  for applying the non-asphalt coating  412  to the substrate  406  to substitute for the roofing asphalt. The illustrated manufacturing process involves passing a continuous sheet of the completed substrate  406  in a machine direction  702  through a series of shingle manufacturing operations. The substrate  406  may move at any suitable speed. 
     While  FIGS. 7-9  illustrate shingle manufacturing processes in which the coating  412  is applied to the substrate prior to the application of the filled asphalt coating. In other embodiments, the asphalt coating may be applied prior to the coating  412 . For example, the roofing filled asphalt coating may be applied in a manner in which the substrate is partially or minimally impregnated with the asphalt and the coating  412  is applied in a subsequent step to fully impregnate the substrate. In another embodiment, the coating  412  may be applied to the mat prior to the asphalt coating as a layer or sheet on the bottom face of the substrate, to substitute for the roofing asphalt. In one version of this embodiment, application of the asphalt coating onto the substrate causes the layer or sheet of non-asphalt coating to melt and impregnate into the substrate. 
       FIG. 7  illustrates an exemplary embodiment of a shingle manufacturing apparatus  700  for forming a shingle component  708 . Referring to  FIG. 7 , in a first step of the shingle manufacturing process, the continuous sheet of completed substrate  406  is payed out from a roll  704 . Alternatively, the sheet of completed substrate  406  can be delivered or fed into the shingle manufacturing process by some other manner. The sheet of completed substrate  406  is passed from the roll  704  or other supply through a coater  706  where the substrate  406  is flooded or saturated with the coating  412  (instead of a roofing asphalt coating) to form the shingle component  708 . The saturated shingle component  708  is then optionally passed to a binder applicator  710  where a binder solution  712  is applied to the saturated shingle component  708 . Any suitable thermosetting or thermoplastic binder may be used, such as for example, traditional phenolic-formaldehyde binders, as well as the more recent formaldehyde-free binders, including polyacrylic binders and carbohydrate, starch or bio-based binders. In an alternative embodiment, the coating  412  and optional binder solution  712  may be applied to the substrate  406  simultaneously or as a single solution. In another alternative embodiment, the binder is optional and the non-asphalt coating is configured to adhere to the substrate  406  without use of a separate binder composition. 
     The shingle component  708  is then optionally passed through an oven  716  that is heated to a suitable temperature to cure the binder  712 . In the exemplary embodiment, the resulting shingle component  708  is fully impregnated with the non-asphalt coating  412  and does not have a discrete layer of the coating  412  on either the top face  408  or bottom face  410 . In other embodiments of  FIG. 7 , a discrete layer of non-asphalt coating may be formed. In the embodiment of  FIG. 7 , the coating  412  substitutes for the roofing asphalt that would have saturated the substrate. 
       FIG. 8  shows another exemplary embodiment of a shingle manufacturing apparatus  800 . The apparatus  800  substitutes coating  412  for the roofing asphalt in the substrate  406 . As with the apparatus  700  of  FIG. 7 , the illustrated shingle manufacturing process of  FIG. 8  involves passing a continuous sheet of the substrate  406  in a machine direction  802  through a series of shingle manufacturing operations to form a shingle component  808 . The substrate  406  may move at any desired speed. 
     In a first step of the shingle manufacturing process, the continuous sheet of completed substrate  406  is payed out from a roll  804 . Alternatively, the sheet of completed substrate  406  can be delivered or fed into the shingle manufacturing process by some other manner. The sheet of completed substrate  406  is passed from the roll  804  through a coater  806  where the coating  412  is selectively applied only to a portion of the substrate  406  to form a coated shingle component  808 . 
     In the exemplary embodiment, the coater  806  selectively applies the coating  412  to the entire bottom face  410  of the substrate  406  to substitute for roofing asphalt on at least the bottom face  410 . The coater  806 , however, may be configured to selectively apply the coating  412  to only a portion of the bottom face  410  or to other portions of the substrate  406 , such as to the top face  408  instead of or along with the bottom face  410 . The coater  806  can be configured to apply the coating  412  in any suitable manner such as, for example, spraying, rolling, or fountain coating. The amount of coating  412  and how long the coating is applied to the substrate  406  can be modified as desired. In this process, the coating  416  could fully impregnate the substrate  406 , partially impregnate the substrate, or not impregnate the substrate to completely, partially, or not substitute for the roofing asphalt in the substrate  406 . The process may also provide a discrete layer of coating  412  on the bottom face  410  with a thickness of the layer that can be varied as desired. In the illustrated embodiment, the coating  412  partially impregnates the substrate  406  and forms the bottom non-asphalt layer  414  of the shingle  400 . The shingle component  808  is optionally heated to a suitable temperature to cure the coating on the shingle component. 
       FIG. 9  shows an exemplary embodiment of an apparatus  900  for completing the manufacturing of an asphalt-based roofing shingle with the shingle components  708  and/or  808 . The illustrated manufacturing process  900  involves passing a shingle component  708  and/or  808  that does not include roofing asphalt in a machine direction  902  through a series of further shingle manufacturing operations. The shingle component  708  and/or  808  may move at any desired speed. In the exemplary embodiment, the shingle component  708  and/or  808  usually moves at a speed of at least about 200 feet/minute (61 meters/minute), and typically at a speed within the range of between about 450 feet/minute (137 meters/minute) and about 800 feet/minute (244 meters/minute). 
     In the manufacturing process, the continuous sheet of shingle component  708  and/or  808  is payed out from a roll  904  or other supply. Alternatively, the apparatus  900  may be a portion of an in-line manufacturing process that includes the apparatus  700  and/or the apparatus  800  for applying the coating  412  to the substrate  406  instead of roofing asphalt and make the roofing component  708  and/or  808 . Thus, the shingle component  708  and/or  808  may not arrive at the apparatus  900  via the roll  904 , but instead is supplied to the apparatus in another suitable manner. The shingle component  708  and/or  808  is passed from the roll  904  through an accumulator  906 . The accumulator  906  allows time for splicing one roll  904  of substrate  406  to another, during which time the shingle component  708  and/or  808  within the accumulator  906  is fed to the manufacturing process so that the splicing does not interrupt manufacturing. 
     Next, the shingle component  708  and/or  808  is passed through a coater  908  where a coating of roofing asphalt  416  is applied to the top face  408  of the shingle component  708  and/or  808 . The roofing asphalt  416  may be applied in any suitable manner. In the illustrated embodiment, a supply of hot, melted asphalt  416  is applied to the top face  408  of the shingle component  708  and/or  808  at immediately prior to a pair of rollers  909 . The shingle component  708  and/or  808  moves between the nip point of the two rollers  909 . The rollers  909  completely cover the top face  408  with a tacky coating of roofing asphalt  416  while no asphalt contacts the bottom face  410  of the substrate  406 . However, in other embodiments, the roofing asphalt  416  could be sprayed on, rolled on, or applied to the shingle component  708  and/or  808  by other means. To the extent that the shingle component  708  and/or  808  is not fully impregnated with the coating  412 , the asphalt  416  may impregnate the substrate  406  where the substrate is not impregnated with the coating  412 , in addition to forming the top asphalt layer  418 . If the substrate  406  of the shingle component  708  and/or  808  is fully impregnated, or substantially fully impregnated, with the coating  412 , the asphalt  416  may adhere to the top face  408  and/or to the non-asphalt coating with little or no impregnation and form the top asphalt layer  418  resulting in an asphalt coated shingle component  910 . Typically the asphalt  416  is highly filled with a ground mineral filler material, amount to at least about 60 percent by weight of the asphalt/filler combination. In one embodiment, the asphalt  416  is in a range from about 350 degree F. to about 400 degree F. In another embodiment, the asphalt  416  may be more than 400 degree F. or less than 350 degree F. The asphalt coated shingle component  910  exits the coater  908  with the asphalt  416  remaining hot. 
     The asphalt coated shingle component  910  may then be passed beneath one or more granule dispensers  912  for the application of granules to the top asphalt layer  418  of the asphalt-coated shingle component  910 . The granule dispensers  912  may be of any type suitable for depositing granules onto the asphalt-coated shingle component  910 . Any desired number of dispensers may be used. 
     After the granules are deposited on the asphalt-coated shingle component  910  by the one or more dispensers  912 , the sheet  910  becomes a granule-covered shingle component  914 . The granule-covered shingle component  914  may then be turned around a slate drum  916  to press the granules into the top asphalt layer  418  and to temporarily invert the sheet so that the excess granules will fall off and will be recovered and reused. The shingle component  910  may also pass through a set of press rolls to complete the embedment of the granules into the filled asphalt coating and through a series of cooling steps after the press rolls and prior to being cut. 
     The granule-covered shingle component  914  may subsequently be fed through a first cutter  918 . The first cutter  918  may cut a series of notches  422  in the granule-covered shingle component  914  to form tabs  424  (see  FIG. 4 ). Further downstream, the granule-covered shingle component  914  may be passed into contact with a second cutter  920  that cuts the granule-covered shingle component  914  into individual shingles  400 . 
     In addition to the property benefits to the shingle  400  provided by the coating  412 , having the bottom face of the shingle  400  be asphalt-free, or substantially asphalt free (e.g. greater than 95% asphalt-free) may provide additional benefits. For example, eliminating asphalt  416  on the bottom face may reduce the amount of asphalt used in the production of the shingle  400 . Using less asphalt  416  results in a lighter shingle  400  which makes for easier handling and transporting of the shingles and the production process can better control the amount of asphalt  416  being used and the overall weight in the shingle. Alternatively, the amount of asphalt normally applied to the bottom face can be applied to the top face  408  to create a thicker top asphalt layer  418 . The thicker top asphalt layer  418  provides additional protection against the elements without increasing the weight of the shingle  400  beyond traditional shingles. Furthermore, the elimination of asphalt on the back face  410  of the substrate  406  of the shingle  400  may make the use of a back coating of sand or mica, and release tape, optional since there is less risk of shingles sticking to each other when packaged and stored at elevated temperatures. Still further, by eliminating the need to impregnate the substrate with the filled asphalt coating, the type of filler used in the filled asphalt coating may be modified without concerns that the use of a modified filler may degrade the substrate. 
     Referring to  FIG. 10 , an exemplary embodiment of a roofing shingle  1000  is illustrated. The roofing shingle  1000  is similar to the roofing shingle  400  in that the shingle  1000  is generally planar and includes a top surface  1002 , a bottom surface  1004 , and includes a substrate  1006  having a top face  1008 , a bottom face  1010  generally parallel to the top face and a non-asphalt coating  1012 . The shingle  1000  also includes an asphalt coating  1016  that forms a discrete top asphalt layer  1018  covering the entire the top face  1008  of the substrate, or substantially the entire top face (e.g. greater than 95% of the top face), and a layer of granules  1020  that covers, and may be partially embedded into, the top asphalt layer  1018 . As with the shingle  400 , the bottom face  1010  of the substrate  1006  is asphalt-free, or substantially asphalt-free. The substrate  1006  of the shingle  1000  is fully, or nearly fully impregnated, with non-asphalt coating  1012 . Little or no impregnation of the substrate  1006  by the asphalt  1016  occurs. The substrate  1006  could be coated with non-asphalt coating  412  by the process illustrated in  FIG. 7 , for example. 
     Referring to  FIGS. 11 and 12 , an exemplary embodiment of a roofing shingle  1100  is illustrated. The roofing shingle  1100  is a laminated shingle including an overlay sheet  1102  laminated to an underlay sheet  1104 . The overlay sheet  1102  includes a substrate  1106  having a top face  1108 , a bottom face  1110  generally parallel to the top face. The substrate  1106  is impregnated with a coating  1112 . The underlay sheet  1104  includes a substrate  1116  having a top face  1118  and a bottom face  1120  generally parallel to the top face. The substrate  1116  is impregnated with the non-asphalt coating  1112 . 
     The overlay sheet  1102  includes a headlap portion  1122  and an exposed portion  1124 . The overlay sheet  1102  overlaps the underlay sheet in the exposed portion. When installed on a roof, the exposed portion  1124  of the overlay sheet is configured to be visible and exposed to the elements while the headlap portion  1122  is configured to be underneath the exposed portion of the next course of shingles. 
     The shingle  1100  also includes an asphalt coating  1126  that forms a discrete top asphalt layer  1128  on the top face  1108  of the exposed portion  1124  of the overlay sheet  1102  and the top face  1118  of the underlay sheet  1104 . A granule layer  1130  may cover, and may be partially embedded into, the top asphalt layer  1118  on the overlay sheet  1102  and the underlay sheet  1104 . 
     The bottom face  1110  of the overlay sheet  1102  and the bottom face  1120  of the underlay sheet  1104  are asphalt-free, or substantially asphalt-free. In addition, the non-asphalt coating  1112  fully impregnates the overlay sheet substrate  1106  and the underlay sheet substrate  1116  to substitute for the roofing asphalt of the shingle. As such, a discrete non-asphalt layer (i.e. separate from the impregnating coating) is not formed on the bottom face  1110  of the overlay sheet  1102  or the bottom face  1120  of the underlay sheet  1104 . In other embodiments, however, the non-asphalt coating need not fully impregnate either substrate  1106 ,  1116  and a discrete non-asphalt layer may be formed on either bottom face  1100 ,  1120 . 
     Unlike the shingle  1000 , however, a portion of the top face  1108  of the overlay sheet  1102  is asphalt-free, or substantially asphalt-free. In particular, in the exemplary embodiment, the headlap portion  1122  of the shingle  1000  is asphalt-free, or substantially asphalt free. The substrates  1106 ,  1116  could be coated with non-asphalt coating  1112  by the process illustrated in  FIG. 7 , for example to substitute the coating for the asphalt. The asphalt  1116  could be selectively applied to the substrates  1106 ,  1116  by a process similar to the process of  FIG. 9 . For example, a supply of hot, melted asphalt  1116  could be selectively applied to a portion of the top face  1108  of the overlay substrate  1106  immediately prior to the pair of rollers  909  such that when the substrate moves between the nip point of the rollers, the asphalt  1116  does not cover the headlap portion  1122  of the overlay substrate  1106 . 
     Referring to  FIG. 14 , an exemplary embodiment of a roofing shingle  1300  is illustrated. The roofing shingle  1300  is similar to the roofing shingle  1000  of  FIG. 10  in that the shingle  1300  has a top surface  1302 , a bottom surface  1304 , and a substrate  1306  that includes a top face  1308 , a bottom face  1310  generally parallel to the top face. The shingle  1300  has a non-asphalt coating  1312  on the bottom face  1310 . The shingle  1300  also includes asphalt  1316  that forms a discrete top asphalt layer  1318  on the top face  1308  of the substrate and a layer of granules  1320  that covers, and may be partially embedded into, the top asphalt layer  1318 . As with the shingle  1000 , the bottom face  1310  of the substrate  1306  is asphalt-free, or substantially asphalt-free. Unlike the shingle  1000 , however, the non-asphalt coating  1312  does not impregnate, or only minimally impregnates, the substrate  1306 . The substrate  1306  is fully impregnated, or substantially fully impregnated, with the asphalt  1316 . 
     The above description of specific embodiments has been given by way of example. From the disclosure given, those skilled in the art will not only understand the general inventive concepts and attendant advantages, but will also find apparent various changes and modifications to the structures and methods disclosed. For example, the general inventive concepts are not typically limited to any roofing application. Thus, for example, use of the inventive concepts to both domestic and commercial roofing applications, are within the spirit and scope of the general inventive concepts. As another example, although the embodiments disclosed herein have been primarily directed to asphalt-based roofing shingles, the general inventive concepts could be readily extended to any roofing material which could benefit from the use of a non-asphalt coated substrate. Furthermore, the general inventive concepts could be readily applied to various shingle designs, such as for example, single layer, three tab shingles or multi-layer, laminate shingles. It is sought, therefore, to cover all such changes and modifications as fall within the spirit and scope of the general inventive concepts, as described and claimed herein, and equivalents thereof.