Abstract:
A process of simultaneously molding either a plurality of shingles or double walled shingles or other substantially planar exterior building products is provided, such that a blow moldable thermoplastic material is provided, of a composite parison that is then blow molded in a hollow mold, to produce novel shingles according to the process. Ventilation and/or insulation can be provided to a hollow interior between spaced apart walls of a double walled shingle.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     In the art of shingle manufacture, particularly shingles for roofing, it has been known to manufacture shingles of bitumen-impregnated mat, with the mat often being of fiberglass construction, and with granules being applied to the bitumen-covered surface of the shingle, often with smaller granules, such as mica or the like, applied to the rear surface of the shingle, also held in place by bitumen on the rear surface of the shingle. Examples of such shingle manufacturing techniques are set forth in U.S. Pat. No. 4,295,445, U.S. Pat. No. 5,181,361, and U.S. Pat. No. 5,501,056, for example.  
         [0002]     It is also known that shingles can be molded from hardenable materials, to simulate natural slate, wood shakes, or other natural materials. An example of molding shingles in the form of tiles is, for example, set forth in U.S. Pat. No. 6,178,703. In that patent, the material of shingle tile formation is essentially a clay, which hardens in a cement-like manner, to yield a fairly heavy shingle.  
       SUMMARY OF INVENTION  
       [0003]     The present invention is directed to simultaneously molding a plurality of shingles. The shingle material can be designed to have certain weatherable features, such as, but not limited to rain and sun resistance, ultraviolet radiation resistance, color acceptance and retention, etc. The material optionally may also include scrap materials, recycled materials, less expensive materials, etc. The material could also include a blow molded polyurethane layer or other foam material, for example to provide an insulation layer in the shingle, for insulating against heat or cold.  
         [0004]     In accordance with this invention, a plurality of shingles can be simultaneously blow molded from a single parison, and with the parison being expanded within the mold to form a plurality of composite shingles within the mold.  
         [0005]     Additionally, in accordance with this invention, a process is provided for molding a plurality of substantially planar exterior building products, of, preferably thermoplastic substantially planar building product material.  
         [0006]     Accordingly, it is a primary object of this invention to provide a novel process for molding a plurality of shingles by blow molding a parison.  
         [0007]     It is another object of this invention to accomplish the above object, wherein the plurality of shingles that are blow molded simultaneously are initially connected together, and then are at least partially or completely severed, to form the plurality of shingles.  
         [0008]     It is yet another object of this invention to accomplish the above objects while providing the interior of the mold with desired surface configurations of three-dimensional type.  
         [0009]     It is yet another object of this invention to accomplish the above objects, where the parison molds the core material to have a plurality of generally flat surfaces, when expanded.  
         [0010]     Accordingly, it is another object of this invention to provide a double walled ventilated substantially planar exterior building product or shingle, which may or may not be insulated.  
         [0011]     It is a further object of this invention to provide a double walled substantially planar exterior building product, preferable of the shingle type, which is insulated.  
         [0012]     Further objects of this invention include the making of shingles in accordance with the processes described with respect to the objects above.  
         [0013]     Other objects and advantages of the present invention will be readily apparent from a reading of the following brief descriptions of the drawing figures, the detailed descriptions of the preferred embodiments, and the appended claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING FIGURES  
       [0014]      FIG. 1  is a plan view of one half of a two-shingle mold in accordance with this invention.  
         [0015]      FIG. 2  is a vertical sectional view, taken through the mold half of  FIG. 1 , generally along the line II-II of  FIG. 1 .  
         [0016]      FIG. 3  is a vertical sectional view, taken through a shingle mold in accordance with this invention, wherein the mold is constructed to simultaneously mold a pair of shingles from a parison, with the mold of  FIG. 3  being shown in the closed position.  
         [0017]      FIG. 4  is a vertical sectional view of the two halves of the mold of  FIG. 3 , spaced apart vertically, with a parison being injected between the two mold halves.  
         [0018]      FIG. 5  is a vertical sectional view similar to those of  FIGS. 3 and 4 , but wherein the two mold halves are closed on the parison, having pinched the same closed, but prior to the blow molding process having taken place.  
         [0019]      FIG. 6  is a vertical sectional view, taken through the mold of  FIGS. 3-5 , but wherein air has been injected into the parison, expanding the same, such that the parison material is expanded outwardly toward and against the surfaces of the two mold halves.  
         [0020]      FIG. 7  is a horizontal sectional view, taken through the parison of  FIG. 6 , and showing the lower mold half of  FIG. 6 , with the illustration of  FIG. 7  having been taken generally along the line VII-VII of  FIG. 6 .  
         [0021]      FIG. 8  is a perspective view of the blow molded parison of  FIGS. 6 and 7 , that has been cooled and removed from the mold, and which comprises the molded configuration of a pair of shingles and their connections together.  
         [0022]      FIG. 9  is a sectional view, taken through the molded structure of  FIG. 8 , generally along the line IX-IX of  FIG. 8 , and wherein two planes are illustrated as being the planes along which the shingle configurations of  FIG. 8  will be separated from the portions of the parison that were molded as connections between the two shingle configurations.  
         [0023]      FIG. 10  is a perspective illustration of one of the two shingles formed following the severance of the shingle configurations pursuant to  FIG. 9 .  
         [0024]      FIG. 11  is a sectional view, taken through the shingle of  FIG. 10 , taken generally along the line XI-XI of  FIG. 10 .  
         [0025]      FIG. 12  is a perspective view of an alternative shingle in accordance with this invention, with the view being similar to that of  FIG. 11 , but wherein the severance of the shingle from the connecting material that connected a pair of opposed shingles, was severed along a plane parallel to the lower surface of the core material, but spaced therefrom.  
         [0026]      FIG. 13  is an elevation view of part of the parison-forming mold, fragmentally illustrated, in vertical orientation.  
         [0027]      FIG. 14  is a sectional view of the parison-forming mold illustrated in  FIG. 13 , wherein the material that will form the parison may be extruded therefrom.  
         [0028]      FIG. 15  is an illustration of the mold is shown in  FIG. 14 , but with the molten parison material being extruded into a tubular parison.  
         [0029]      FIG. 16  is an enlarged fragmentary view of a portion of the parison-forming mold of  FIG. 15 , wherein the extrusion is more clearly illustrated.  
         [0030]      FIG. 17  is a perspective view, similar to that of  FIG. 8 , but wherein the connected two molded shingles are shown in a different embodiment, of uniform thickness throughout, as distinguished from the tapered configuration illustrated in  FIG. 9 .  
         [0031]      FIG. 18  is a sectional view, similar to that of  FIG. 9 , but of the uniform-thickness shingle embodiment of  FIG. 17 , taken generally along the line XVIII-XVIII of  FIG. 17 .  
         [0032]      FIG. 19  is a perspective view of a shingle severed in accordance with the severance lines shown in  FIG. 18 , and is otherwise similar to the shingle embodiment of  FIG. 10 , but of a different embodiment.  
         [0033]      FIG. 20  is a sectional view of the shingle embodiment of  FIG. 19 , taken generally along the line XX-XX of  FIG. 19 .  
         [0034]      FIG. 21  is a sectional view, taken through a four-shingle blow mold in accordance with this invention.  
         [0035]      FIG. 22  is a view of one half of the mold of  FIG. 21 , taken generally along the line XXII-XXII of  FIG. 21 .  
         [0036]      FIG. 23  is a sectional view, through the four-shingle mold of  FIG. 21 , after the parison has been blow molded against the interior surfaces of the two mold halves of  FIG. 21 , wherein the four two-layer shingles are illustrated connected together.  
         [0037]      FIG. 24  is a fragmentary sectional view of a portion of two of the shingles of  FIG. 23 , with cut planes being illustrated as to where the severance of the shingles will be made, to separate two adjacent shingles from the connecting material that connects them during the molding process.  
         [0038]      FIG. 25  is a sectional view like that of  FIG. 18 , but wherein the embodiment is not severed, and with additional ventilation holes between the two upper and lower molded shingle layers.  
         [0039]      FIG. 26  is a sectional view similar to that of  FIG. 25 , but wherein a foam is injected between the two upper and lower shingle layers of the shingle embodiment.  
         [0040]      FIG. 27  is a sectional view similar to that of  FIG. 26 , but wherein the foam inside the embodiment is removed between the ventilation openings. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0041]     Referring now to the drawings in detail, reference is first made to  FIG. 1 , wherein a blow mold half  20  of a blow mold  21  is illustrated, having a cavity  22  therein, defined by a generally flat but tapered mold surface  23 , having three-dimensional configurations  24  therein, which configurations  24  may be protrusions or may be relief as shown, with the configurations  24  being adapted to simulate various natural formations in a shingle to be molded in the mold half  21 , such as to simulate natural slate, cedar shakes, or like aesthetic variations as may be desired to design into a synthetic shingle made in accordance with this invention.  
         [0042]     The mold half  20  has an upper parting plane  25  and the cavity  22  is also defined in part by end surfaces  26 ,  27  and side surfaces  28  and  30 , with connecting surfaces  31 ,  32 ,  33  and  34 , which are shown as being chamfered, although the same could be rounded, arcuate, or take on any other configuration that may be desired for the shingle that is to be blow molded in the mold  21 . The rightmost end  34  of the mold half  20  is provided with a parison inlet  35 . The left-most end  36  of the mold half  20  as shown in  FIGS. 1 and 2  is provided with a recessed parison pinch-off zone  37  as shown.  
         [0043]     With reference now to  FIG. 3 , it will be seen that the mold  21  is comprised of a lower mold half  20  and an upper mold half  40 , with the upper mold half  40  essentially being a mirror image of the mold half  20 . However, it will be understood that the mold halves  20  and  40  need not have recesses  22  and  42 , respectively that are mirror images of each other, in that two entirely different configurations might be desired for lower and upper recesses  22  and  42 , as may be desired.  
         [0044]     With reference to  FIG. 4 , it will be seen that the lower and upper mold halves  20  and  40  have been vertically separated, to be spaced apart, so that a parison-forming mold  43  may enter from the right side as illustrated in  FIG. 4 , bringing a parison  44  between the mold halves  20  and  40 , as shown.  
         [0045]     With reference to  FIG. 5 , it will be seen that the two mold halves  20  and  40  have been brought together vertically, so that the parison  44  is pinched off at the right end of the mold  21 , at  47 , and likewise is pinched off at the left end  48 , as shown, leaving a void  50  inside the parison  44 , into which is received at the right end, an air or other gas inlet  51  of the parison-forming mold  43 .  
         [0046]     With reference to  FIG. 6 , it will be seen that air (or other gas) is provided through the inlet  51  of the parison-forming mold  43 , to fill the void  50  inside the parison  44 , and expand the same outwardly against the interior walls of the mold half  20 ,  40 , as shown by the arrows  52 , such that the material of the parison  44  engages against the interior surfaces of the mold as shown in  FIGS. 6 and 7   
         [0047]     It will be understood that the mold halves  20 ,  40  have their walls  53 ,  54  constructed in a conventional manner to allow air outside the parison  44 , but inside the interior walls of the mold halves  20 ,  40  to escape therefrom as air is injected inside the parison  44 . Such conventional means for providing porosity for the walls  53  and  54  may include a plurality of air escape ports (not shown), extending through the walls  53 ,  54 , in various locations, or may include the construction of the walls  53 ,  54  of the mold halves  20 ,  40  as being sufficiently foraminous, to allow air to escape therefrom, as air is injected through the inlet  51 , into the cavity  50 , so that the parison  44  may expand against the interior surfaces of the mold halves  20 ,  40 .  
         [0048]     With reference now to  FIG. 8 , it will be seen that the expanded parison  44 , having been cooled in the mold by any conventional means (not shown) and removed from the mold, will be comprised of upper and lower shingle formations  56 ,  57 , connected on four sides by parison connection zones  58 ,  60 ,  61  and  62 , with the exterior surfaces of the shingle formations  56  and  57  being provided with three-dimensional configurations  63 , either in the form of relief zones or projections, depending upon the three-dimensional configurations  24  that have been molded thereinto, to form the configurations  63 .  
         [0049]     It will also be seen in  FIG. 9 , that planes of severance  64 ,  65  are provided, that are essentially parallel to the respective inner surfaces  66 ,  67 , and most preferably in the same planes  64 ,  65  respectively, such that the parison connection portions  58 ,  60 ,  61  and  62 , may be severed along those planes  64 ,  65 , to yield two shingles  70 , having three-dimensional aesthetic configurations  63  in the surface  71  of the material  72 , as may be desired.  
         [0050]     It will also be understood that the shingle  70  shown in  FIGS. 10 and 11  is one which would have a greater thickness at its right end than at its left end, in that its right end would present a shingle edge  74  that would normally be the butt edge of the shingle, where as the left-most edge  75  as illustrated in  FIGS. 10 and 11  would normally represent the upper headlap edge of the shingle in the installed condition on a roof.  
         [0051]     With reference to  FIG. 12  it will be seen that an alternative shingle  80  is illustrated. However, in the shingle  80  of  FIG. 12 , it is demonstrated that the plane  83  of severance of shingles from parison connection portions as described above, is spaced from the undersurface  84 , but generally parallel to the generally flat plane  84  that represents the undersurface to yield thicker peripheral edges  85 ,  86 ,  87 , than if the plane  83  were substantially aligned with the surface  84 , such that the shingle  80  when installed on a roof can yield an even thicker appearance than that of the shingle  70  of  FIG. 11 .  
         [0052]     With reference now to  FIGS. 13-16 , it will be seen that the parison-forming mold  43  is provided with its air tube  51  protruding downwardly therefrom, as shown, and that an extrusion cylinder  90  is provided, for receiving parison-forming material in the cylindrical void  92 , which material will be provided under pressure, to be extruded therefrom, as shown in  FIG. 15 , whereby parison-forming material  44  will be extruded to yield a parison  44  as described above.  
         [0053]     With reference now to  FIGS. 17 and 18 , an alternative double shingle structure  100  to the double shingle structure formed from the parison  44  of  FIG. 8  is illustrated, comprising two shingle formations  101  and  102 , like those shown in  FIG. 9 , connected together by parison connections  103 ,  104 ,  105  and  106 , to be severed along severance planes  107 ,  108 , in the manner described above with respect to  FIGS. 8 and 9 , but wherein the shingle formations  101 ,  102  are of uniform thicknesses, as shown, as distinguished from the tapered thickness formation shown with respect to the shingle formations of  FIGS. 8 and 9 . Otherwise, the shingle formations of  FIGS. 17 and 18  are similar to those of  FIGS. 8 and 9 .  
         [0054]      FIGS. 19 and 20  represent the separate shingles formed from the formed and cooled double shingle structure  100  of  FIGS. 17 and 18 , after the parison connection portions  103 - 106  have been severed therefrom, to yield a pair of shingles  110 .  
         [0055]     With reference now to  FIGS. 21 through 24 , it will be seen that a mold  120  may be provided in the form of mold halves  121  and  122 , which, together, can provide a means for simultaneously making a greater number of shingles in the same mold. For example, in the mold  120 , four shingle-forming recesses  123 ,  124 ,  125  and  126  are provided by the two mold halves  121  and  122 , for receiving a parison therein after the mold halves  121  and  122  are separated along the parting plane  127 , with each of the shingle-forming recesses  123 - 126  being provided with relief or projections for forming three-dimensional surface configurations for the exterior of the capstock material of a shingle formed therein.  
         [0056]     With specific reference to  FIGS. 23 and 24  it will be seen that four shingle formations  130  through  133  are made simultaneously in the mold  120 , by bringing a parison between the mold halves  121 ,  122 , in the same manner described above, with air being injected into the parison, with each shingle formation  130  through  133  being disposed against the interior surface of the mold, as shown, and with the shingle formations  130 - 133  being connected by suitable parison connections  134 ,  135 ,  136  and  137 , that will be severed therefrom by cuts made along suitable severance planes  138 ,  140  as shown in  FIG. 24 .  
         [0057]     Thus, the result of blow molding a parison in a mold  120  will yield four separate shingles.  
         [0058]     It will also be apparent that in a multiple shingle mold such as shown in the various Figures, each shingle-forming recess need not be identically constructed, but that different aesthetic configurations may be provided in a single mold.  
         [0059]      FIG. 25  is similar to that of  FIG. 18 , but wherein the shingle structure  200  is retained in its molded form, and is not separated by horizontal cut or separation lines as is the embodiment of  FIG. 18 , and wherein opposed planar surfaces of the substantially planar exterior building product  200  remain spaced apart by the zone  208 . Thus, the opposed walls of material are indicated by the numerals  201  and  202 , with right and left side walls  203  and  204 , and end walls  205  and its opposite wall (unnumbered) defining the ventilation space  208 . A plurality of ventilation holes  207  are provided in side walls  203  and  204 , although in the sectional view of  FIG. 25  only two openings  207  are illustrated. Thus, there is presented a hollow shingle  200  that may be ventilated to reduce the effect of heat buildup when applied to a roof, especially during hot weather conditions.  
         [0060]     With reference now to  FIG. 26 , a shingle embodiment  300  is provided, comprised of two layers of material, such layers being identified by numerals  301  and  302 , by sidewalls  303  and  304 , and end walls (unnumbered). A polyurethane or other foam is injection molded into one of the openings  307 , by means of an injector  310 , delivering the expandable foam in the direction of the arrow  311 , such that the foam expands inside the opening in the double walled embodiment  300 , as shown in  FIG. 26 , for purposes of insulating the double walled shingle  300  or other substantially planar exterior building product, either against heat build-up when disposed on a roof subject to hot weather conditions, or for purposes of retaining air conditioning or heat within the building to which the shingle  300  is applied.  
         [0061]     With respect to  FIG. 27 , an illustration like that of  FIG. 26  is provided, but wherein a bank of drills or other cutting or clearing mechanisms  11  are provided, generally rotateably driven as at  412 , to cut a plurality of side-to-side ventilation openings  405  between the side walls  403 ,  404  of the shingle  400 , between ventilation openings  407 , and generally parallel to the opposing major walls  401 ,  402  of the double walled embodiment  400 , whereby the insulation layers  409 ,  410  will provide insulation as described above with respect to the embodiment of  FIG. 26 , but wherein the elongated holes  405  between the ventilation openings  407  provide ventilation in accordance with that which is described above with respect to the embodiment of  FIG. 25 .  
         [0062]     It will be apparent from the foregoing that various modifications may be made in the process steps of this invention, as well as in the materials and in the mold configurations, to yield a wide variety of novel shingles, all made in accordance with the novel processes of this invention, and that various modifications may be made in the details of the process and molding structure, to yield various variations in the shingles made thereby, all within the spirit and scope of the invention as defined in the appended claims.