Abstract:
A roofing shingle is provided. The roofing shingle includes an overlay sheet including a headlap portion and a tab portion and an underlay sheet secured to the overlay sheet such that a region of the underlay sheet overlaps a region of the headlap portion of the overlay sheet. Said underlay sheet has a substantially uniform thickness. A reinforcement member is secured to the headlap portion. The reinforcement member is formed from a material selected from the group consisting of paper, film, scrim, woven, and non-woven material. The reinforcement member and the portion of the headlap portion to which the reinforcement member is secured to improve nail pull-through. At least some of the reinforcement member does not overlap the overlapping regions of the headlap portion and the underlay sheet. Said reinforcement member provides said overlay sheet with a non-uniform thickness.

Description:
RELATED APPLICATIONS 
       [0001]    This application is a continuation patent application of pending U.S. patent application Ser. No. 11/198,522, filed Aug. 5, 2005, the disclosure of which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    This invention relates to a shingle, such as a roofing shingle, and in particular, to a roofing shingle having an improved nail zone. 
       BACKGROUND OF THE INVENTION 
       [0003]    Asphalt-based roofing materials, such as roofing shingles, roll roofing and commercial roofing, 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 material is constructed of a substrate such as a glass fiber mat or an organic felt, an asphalt coating on the substrate, and a surface layer of granules embedded in the asphalt coating. 
         [0004]    A common method for the manufacture of asphalt shingles is the production of a continuous sheet of asphalt material followed by a shingle cutting operation, which cuts the material into individual shingles. In the production of asphalt sheet material, either a glass fiber mat or an organic felt mat is passed through a coater containing hot liquid asphalt to form a tacky, asphalt coated sheet. Subsequently, the hot asphalt coated sheet is passed beneath one or more granule applicators, which discharge protective and decorative surface granules onto portions of the asphalt sheet material. 
         [0005]    In certain types of shingles, it is especially desired that the shingles define a sufficiently wide area, often known in the industry as the “nail zone,” in order to make installation of roofs using shingles, such as laminated shingles, more efficient and secure. One or more lines or other indicia painted or otherwise marked longitudinally on the surface of the shingle may define such a nail zone. It is especially desired that the shingles define a nail zone that allows the installers to have some latitude in the nail placement. 
         [0006]    Additionally, the leading edge of some shingles may experience lift off in high wind situations. Therefore, there is also a need for shingles where the shingles have a sufficiently high nail pull-through value so that the installed shingles have improved performance in high wind situations. 
       SUMMARY OF THE INVENTION 
       [0007]    The above objects as well as other objects not specifically enumerated are achieved by a roofing shingle. The roofing shingle includes an overlay sheet including a headlap portion and a tab portion and an underlay sheet secured to the overlay sheet such that a region of the underlay sheet overlaps a region of the headlap portion of the overlay sheet. Said underlay sheet has a substantially uniform thickness. A reinforcement member is secured to the headlap portion. The reinforcement member is formed from a material selected from the group consisting of paper, film, scrim, woven, and non-woven material. The reinforcement member and the portion of the headlap portion to which the reinforcement member is secured to improve nail pull-through. At least some of the reinforcement member does not overlap the overlapping regions of the headlap portion and the underlay sheet. Said reinforcement member provides said overlay sheet with a non-uniform thickness. 
         [0008]    According to this invention there is also provided a roofing shingle. The roofing shingle includes an overlay sheet including a headlap portion and a tab portion. An underlay sheet is secured to the overlay sheet such that a region of the underlay sheet overlaps a region of the headlap portion of the overlay sheet, said underlay sheet having a uniform thickness. A reinforcement member is secured to the headlap portion, the reinforcement member being formed from a woven material. At least some of the reinforcement member does not overlap the overlapping regions of the headlap portion and the underlay sheet. The headlap portion defines a first nail pull-through value. The reinforcement member and the headlap portion define a second nail pull-through value that is at least 13.3 percent greater than the first nail pull-through value. Said reinforcement member provides said overlay sheet with a non-uniform thickness. 
         [0009]    Various objects and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the various embodiments, when read in light of the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1  is a schematic elevational view of an apparatus for making shingles according to the invention. 
           [0011]      FIG. 2  is a perspective view of a laminated shingle having a reinforcement member in accordance with this invention. 
           [0012]      FIG. 3  is a schematic sectional view of a pair of laminated roofing shingles of the prior art stacked together, shown in exaggerated thickness to illustrate humping of the stacked shingles. 
           [0013]      FIG. 4  is a schematic sectional view of a pair of laminated roofing shingles according to the invention stacked together, shown in exaggerated thickness to illustrate how the reinforcement members of adjacent shingles cooperate to reduce humping of the stacked shingles. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    Referring now to the drawings, there is shown in  FIG. 1  an apparatus  10  for manufacturing an asphalt-based roofing material according to the invention. In the illustrated embodiment, the manufacturing process involves passing a continuous sheet  12  in a machine direction (indicated by the arrows) through a series of manufacturing operations. The sheet 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). The sheet, however, may move at any desired speed. 
         [0015]    In a first step of the illustrated manufacturing process, a continuous sheet of substrate or shingle mat  12  is payed out from a roll  14 . The substrate can be any type known for use in reinforcing asphalt-based roofing materials, such as a non-woven web of glass fibers. The shingle mat  12  may be fed through a coater  16  where an asphalt coating is applied to the mat  12 . The asphalt coating can be applied in any suitable manner. In the illustrated embodiment, the mat  12  contacts a roller  17 , that is in contact with a supply of hot, melted asphalt. The roller  17  completely covers the mat  12  with a tacky coating of hot, melted asphalt to define a first asphalt coated sheet  18 . In other embodiments, however, the asphalt coating could be sprayed on, rolled on, or applied to the sheet by other means. Typically, the asphalt material is highly filled with a ground stone filler material, amounting to at least about 60 percent by weight of the asphalt/filler combination. 
         [0016]    A continuous strip of a reinforcement material or tape  19 , as will be described in detail herein, may then be payed out from a roll  20 . The reinforcement tape  19  adheres to the first asphalt coated sheet  18  to define a second asphalt coated sheet  22 . In one embodiment, the reinforcement tape  19  is attached to the sheet  18  by the adhesive mixture of the asphalt in the first asphalt coated sheet  18 . The reinforcement tape  19 , however, may be attached to the sheet  18  by any suitable means, such as other adhesives. In one embodiment, the tape  19  is formed from polyester. In another embodiment, the tape  19  is formed from polyolefin, such as polypropylene or polyethylene. The tape  19 , however, can be formed from any material for reinforcing and strengthening the nail zone of a shingle, such as, for example, paper, film, scrim material, and woven or non-woven glass. 
         [0017]    The resulting second asphalt coated sheet  22  may then be passed beneath a series of granule dispensers  24  for the application of granules to the upper surface of the second asphalt coated sheet  22 . The granule dispensers can be of any type suitable for depositing granules onto the asphalt coated sheet. A granule dispenser that can be used is a granule valve of the type disclosed in U.S. Pat. No. 6,610,147 to Aschenbeck. The initial granule blender  26  may deposit partial blend drops of background granules of a first color blend on the tab portion of the second asphalt coated sheet  22  in a pattern that sets or establishes the trailing edge of subsequent blend drops of a second color blend (of an accent color) and a third color blend (of a different accent color). For purposes of this patent application, the first color blend and the background granules are synonymous. The use of initially applied partial blend drops to define the trailing edge of subsequent blend drops is useful where accurate or sharp leading edges are possible, but accurate trailing edges at high shingle manufacturing speeds are difficult. 
         [0018]    As is well known in the art, blend drops applied to the asphalt coated sheet are often made up of granules of several different colors. For example, one particular blend drop that is supposed to simulate a weathered wood appearance might actually consist of some brown granules, some dark gray granules, and some light gray granules. When these granules are mixed together and applied to the sheet in a generally uniformly mixed manner, the overall appearance of weathered wood is achieved. For this reason, the blend drops are referred to as having a color blend, which gives an overall color appearance. This overall appearance may be different from any of the actual colors of the granules in the color blend. Also, blend drops of darker and lighter shades of the same color, such as, for example, dark gray and light gray, are referred to as different color blends rather than merely different shades of one color. 
         [0019]    As shown in  FIG. 1 , the series of dispensers  24  includes four color blend blenders  26 ,  28 ,  30 , and  32 . Any desired number of blenders, however, can be used. The final blender may be the background blender  34 . Each of the blenders may be supplied with granules from sources of granules, not shown. After the blend drops are deposited on the second asphalt coated sheet  22 , the remaining, uncovered areas are still tacky with warm, uncovered asphalt, and the background granules from the background blender  34  will adhere to the areas that are not already covered with blend drop granules. After all the granules are deposited on the second asphalt coated sheet  22  by the series of dispensers  24 , the sheet  22  becomes a granule covered sheet  40 . 
         [0020]    In one embodiment, the reinforcement tape  19  includes an upper surface to which granules substantially will not adhere. The reinforcement tape  19 , however, may include an upper surface to which granules will adhere. For example, the apparatus  10  may include any desired means for depositing granules onto substantially the entire second asphalt coated sheet  22 , except for the portion of the second asphalt coated sheet  22  covered by the tape  19 , as best shown in  FIG. 2 . Alternately, granules may be deposited onto substantially the entire second asphalt coated sheet  22 , including the tape  19 , but wherein the reinforcement tape  19  includes an upper surface to which granules substantially will not adhere. 
         [0021]    The granule covered sheet  40  may then be turned around a slate drum  44  to press the granules into the asphalt coating and to temporarily invert the sheet so that the excess granules will fall off and will be recovered and reused. Typically, the granules applied by the background blender  34  are made up by collecting the backfall granules falling from the slate drum  44 . 
         [0022]    The granule covered sheet  40  may subsequently be fed through a rotary pattern cutter  52 , which includes a bladed cutting cylinder  54  and a backup roll  56 , as shown in  FIG. 1 . If desired, the pattern cutter  52  can cut a series of cutouts in the tab portion of the granule covered sheet  40 , and cut a series of notches in the underlay portion of the granule covered sheet  40 . 
         [0023]    The pattern cutter  52  may also cut the granule covered sheet  40  into a continuous underlay sheet  66  and a continuous overlay sheet  68 . The underlay sheet  66  may be directed to be aligned beneath the overlay sheet  68 , and the two sheets may be laminated together to form a continuous laminated sheet  70 . As shown in  FIG. 1 , the continuous underlay sheet  66  may be routed on a longer path than the path of the continuous overlay sheet  68 . Further downstream, the continuous laminated sheet  70  may be passed into contact with a rotary length cutter  72  that cuts the laminated sheet into individual laminated shingles  74 . 
         [0024]    In order to facilitate synchronization of the cutting and laminating steps, various sensors and controls may be employed. For example, sensors, such as photo eyes  86  and  88  can be used to synchronize the continuous underlay sheet  66  with the continuous overlay sheet  68 . Sensors  90  can also be used to synchronize the notches and cutouts of the continuous laminated sheet with the end cutter or length cutter  72 . 
         [0025]    In one embodiment, the reinforcement tape may be attached to the shingle mat  12  prior to the application of the asphalt coating, as shown at  19 A in  FIG. 1 . The tape  19 A may be attached to the shingle mat  12  by any suitable means, such as hot, melted asphalt, or other adhesives. 
         [0026]    In another embodiment, the reinforcement tape may be attached to the granule covered sheet  40 , as shown at  19 B in  FIG. 1 . The tape  19 B may be attached to the granule covered sheet  40  by any suitable means, such as hot, melted asphalt, or other adhesives. 
         [0027]    In another embodiment, the reinforcement tape may be attached to a lower surface (downwardly facing as viewed in  FIG. 1 ) of the mat  12 , the first asphalt coated sheet  18 , the second asphalt coated sheet  22 , or the granule covered sheet  40 , as shown at  19 C and  19 D in  FIG. 1 . The tape  19 C may be attached to the mat  12 , the first asphalt coated sheet  18 , the second asphalt coated sheet  22 , or the granule covered sheet  40  by any suitable means, such as hot, melted asphalt, other adhesives, or suitable fasteners. In such an embodiment, the reinforcement tape  19 C and  19 D may be attached to the lower surface of the nail zone of either of the overlay sheet  68  or the underlay sheet  66 , thereby reinforcing and strengthening the nail zone as described herein. 
         [0028]    It will be understood, however, that in any of the embodiments described herein, reinforcement material may be applied as an extruded or liquid material, such as a polymer, that will adhere to the mat  12 , the first sheet  18 , the second sheet  22 , the granule covered sheet  40 , or the lower surface of the underlay sheet  66  or the overlay sheet  68 . Additionally, the reinforcement material may be applied to the laminated roofing shingle  74 , as described below. 
         [0029]    Referring now to  FIG. 2 , a laminated roofing shingle is shown generally at  74 . In the illustrated embodiment, the shingle  74  includes the overlay sheet  68  attached to the underlay sheet  66  and has a first end  74 A and a second end  74 B. The shingle  74  also includes a longitudinal axis A. The overlay sheet  68  may include a headlap portion  76  and a tab portion  78 . The headlap portion  76  may include a lower zone  76 A and an upper zone  76 B. The tab portion  78  defines a plurality of tabs  80  and cutouts  82  between adjacent tabs  80 . In the illustrated embodiment, the tab portion  78  includes four tabs  80 , although any suitable number of tabs  80  may be provided. The headlap portion  76  and the tabs  80  may include one or more granule patterns thereon. Each cutout  82  has a first height H 1 . In the illustrated embodiment, the cutouts  82  are shown as having the same height H 1 . It will be understood however, that each cutout  82  may be of different heights. A line B is collinear with an upper edge  82 A of the cutouts  82  and defines an upper limit of an exposed region  84  of the underlay sheet  66 . In the illustrated embodiment, the height of the exposed region  84  is equal to the first height H 1 , although the height of the exposed region  84  may be any desired height. In a shingle wherein the cutouts  82  have different heights, the line B may be collinear with an upper edge  82 A of the cutout  82  having the largest height. In the illustrated embodiment, the overlay sheet  68  has a second height H 2 . 
         [0030]    The reinforcement tape  19  may be disposed longitudinally on the headlap portion  76 . In the illustrated embodiment, the tape  19  extends longitudinally from the first end  74 A to the second end  74 B of the shingle  74  within the lower zone  76 A of the headlap portion  76 . A lower edge  19 A of the tape  19  may be spaced apart from the line B by a distance D 1 , and an upper edge  19 B of the tape  19  may be spaced apart from the line B by a distance D 2 . In one embodiment, the distance D 1  is within the range of from about ¼ inch to about ¾ inch. In another embodiment, the distance D 1  is about ½ inch. In one embodiment, the distance D 2  is within the range of from about 1¾ inches to about 2¼ inches. In another embodiment, the distance D 2  is about 2 inches. The distances D 1  and D 2  may, however, be of any other desired length. For example, if desired, the tape  19  may substantially cover the entire headlap portion  76  of the overlay sheet  68 . It will be further understood, however, that one or more additional lengths of tape may be disposed longitudinally on the headlap portion  76 , such as shown by the phantom line  19 ′ in  FIG. 2 . It will be understood that the reinforcement material need not extend from the first end  74 A to the second end  74 B of the shingle  74 , and may be disposed in one or more sections or portions on the shingle  74 . 
         [0031]    The tape  19  defines a nail zone  98  and may include text such as “nail here •”, as shown in  FIG. 2 . It will be understood, however, that any other text or other indicia may be included on the tape  19 . It will also be understood that the tape  19  can be provided without such text or indicia. Such indicia on the tape  19  ensure that the nail zone  98  may be easily and quickly identified by the shingle installer. 
         [0032]    In the embodiment illustrated in  FIG. 2 , the underlay sheet  66  includes a leading edge  66 A and a trailing edge  66 B and has a third height H 3 . In the illustrated embodiment, the trailing edge  66 B of the underlay sheet  66  is spaced apart from the line B by a distance D 3 . As shown, the distance D 3  is about ⅜ inch, however, the distance D 3  may be any desired distance. 
         [0033]    In the illustrated embodiment, the third height H 3  of the underlay sheet  66  is less than one-half the second height H 2  of the overlay sheet  68 . The overlay sheet  68  and the underlay sheet  66  thereby define a two-layer portion of the laminated shingle  74  and a single-layer portion of the laminated shingle  74 , wherein at least a portion of the tape  19  is adhered to the single-layer portion of the laminated shingle  74 . Alternately, the third height H 3  of the underlay sheet  66  may be equal to one-half the second height H 2  of the overlay sheet  68 , or greater than one-half of the second height H 2  of the overlay sheet  68 . Such a relationship between the underlay sheet  66  and the overlay sheet  68  allows the tape  19  to be positioned such that a reinforced nail zone is provided at a substantially single-layer portion of the shingle  74 . 
         [0034]    In another embodiment of the invention, a layer of material, such as talc or sand, may be applied to the first asphalt coated sheet  18  shown in  FIG. 1 . The material may be applied by any desired means to an upper surface of the first asphalt coated sheet  18 . In one embodiment, the material may be applied to the portion of the first asphalt coated sheet  18  that will become the portion of the overlay sheet  66  shown covered by the tape  19  in  FIG. 2 . Such a material may reduce tackiness of the portions of the second asphalt coated sheet  22  to which the material has been applied, and thereby provide a surface to which granules substantially will not adhere. 
         [0035]    In the exemplary shingle  74  illustrated in  FIG. 2 , the shingle  74  may have a nail pull-through value, measured in accordance with a desired standard, such as prescribed by ASTM test standard D3462. For example, the shingle  74  may have a nail pull-through value that is greater than in an otherwise identical shingle having no such tape  19 . In one embodiment, the shingle  74  may have a nail pull-through value within the range of from about ten percent to about 100 percent greater than in an otherwise identical shingle having no such tape  19 . In another embodiment, the shingle  74  may have a nail pull-through value about 50 percent greater than in an otherwise identical shingle having no such tape  19 . 
         [0036]    In another embodiment, a shingle having a reinforcement tape  19  formed from polyester film having a thickness of about 0.5 mils, may have a nail pull-through value about 13.3 percent greater than in an otherwise identical shingle having no such tape  19 . 
         [0037]    In another embodiment, a shingle having a reinforcement tape  19  formed from polyester film having a thickness of about 3.0 mils, may have a nail pull-through value about 62.3 percent greater than in an otherwise identical shingle having no such tape  19 . 
         [0038]    In another embodiment, a shingle having a reinforcement tape  19  formed from polyester film having a thickness of about 4.0 mils, may have a nail pull-through value about 86.0 percent greater than in an otherwise identical shingle having no such tape  19 . 
         [0039]    In another embodiment, a shingle having a reinforcement tape  19  formed from polyester film having a thickness of about 5.0 mils, may have a nail pull-through value about 112.7 percent greater than in an otherwise identical shingle having no such tape  19 . 
         [0040]    Because there may be substantially no granules in the portion of the overlay sheet  68  covered by the tape  19 , the weight of the shingle  74  may be reduced relative to an otherwise identical shingle having no such tape  19 . For example, the weight of the exemplary shingle  74  illustrated in  FIG. 2 , may be reduced within the range of from about four percent to about six percent relative to the weight of an otherwise identical shingle having no such tape  19 . The material and transportation cost may also be reduced. 
         [0041]    Although the invention has been disclosed in the context of a laminated shingle  74 , it will be understood that the reinforcement tape  19  may be attached to any other type of shingle, such as a single layer shingle. 
         [0042]    As shown in  FIG. 3 , laminated roofing shingles  100  of the prior art are stacked in a bundle  102 . Only a pair of such shingles  100  are illustrated in  FIG. 3 , with every other shingle  100  inverted and turned 180 degrees. It will be understood, however, that the shingles  100  may be stacked such that every other of such shingles  100  are either inverted or turned 180 degrees, or both. This stacking method minimizes uneven build in the bundle  102  caused by the difference in thickness between the area of the shingle  100  that includes the underlay sheet  106  and the area that does not include the underlay sheet  106 . A problem may occur, however, along a central area  108  of the bundle  102  because central areas  110  of the shingles  100  are double-layered, whereas the cutout portions  112  of the shingles  100  adjacent the central areas  110  are single-layered. The difference in thickness causes a ridge or hump  114  along the central area  108  of the bundle  102  that becomes progressively higher as the number of shingles  100  in the bundle  102  increases. 
         [0043]      FIG. 4  is a schematic sectional view of a representative pair of stacked shingles  74  manufactured according to the present invention. As shown in  FIG. 4 , the laminated roofing shingles  74  are stacked such that every other of the shingles  74  is inverted and turned 180 degrees relative to an adjacent one of the shingles  74  to define a bundle  99 . It will be understood, however, that the shingles  74  may be stacked such that every other of such shingles  74  are either inverted or turned 180 degrees, or both. The bundle  99  includes a central area  92 . In the illustrated embodiment, the central area  92  includes the lower zones  76 A and reinforcement tape  19  of each shingle  74 , and includes the portion of each laminated roofing shingle  74  wherein the shingle  74  is double-layered. In contrast to the prior art shingles  100 , when the laminated shingles  74  of the invention are stacked, the areas of the adjacent shingles  74  having no granules, such as the areas covered by the reinforcement tapes  19 , cooperate to advantageously reduce humping in the central area  92  of the bundle of stacked shingles  74 . As best shown in  FIG. 4 , the central area  92  of the bundle, as represented by the pair of shingles  74  illustrated, has a fourth height H 4  substantially identical to a fifth height H 5  of a remainder of the bundle outside of the central area  92 . 
         [0044]    The principle and mode of operation of this invention have been described in its various embodiments. However, it should be noted that this invention may be practiced otherwise than as specifically illustrated and described without departing from its scope.