Patent Publication Number: US-11384458-B2

Title: Woven geotextile fabrics with integrated geotextile grids or geogrids

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62/728,469 filed Sep. 7, 2018 and U.S. Provisional Patent Application No. 62/730,348 filed Sep. 12, 2018. The entire disclosures of the above provisional applications are incorporated herein by reference. 
    
    
     FIELD 
     The present disclosure relates to woven geotextile fabrics with integrated geotextile grids or geogrids. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Geotextile grids or geogrids are commonly used for reinforcement and stress control in areas such as retaining walls or subbase soils. Geogrids are commonly made from synthetic materials that result in stiffness and strength much higher than soils alone. 
     Geogrids usually have ribs in both the machine direction and the transverse or cross machine direction. Between these ribs are a series of open areas or apertures. But there are other geogrids on the market that utilize a multidirectional or triaxial set of ribs. 
     Geogrids can be manufactured using several different technologies including a “punch and draw” method or an extrusion method. In the punch and draw method, a synthetic plastic sheet is punched and then drawn in both the machine direction and the transverse or cross machine direction. Or, in the case of the extrusion method, the geogrid may be extruded from a special die and then drawn in each direction. 
     Geogrids can be woven from strands of high tenacity yarns (e.g., polyester, polyethylene terephthalate (PET), etc.) and then coated with synthetic substances (e.g., polyvinyl chloride (PVC), etc.). And, geogrids can be made using technology to bond the ribs together at certain intervals to achieve the desired results. All the geogrids mentioned above are characterized by having very high strengths with a predetermined number of ribs with crossing intersections and wide open apertures. 
     In contrast to geogrids, geotextile fabrics are permeable fabrics made using either woven or nonwoven technologies. Geotextile fabrics may serve the purposes of reinforcement, filtration, separation, confinement, and protection of soils. Characteristics of geotextile fabrics can generally be grouped by strength, hydraulic, and sediment retention properties. Geotextile fabrics are manufactured to allow water to pass through while soil and sediment are retained. 
     The engineering community specifies the use of both geogrids and geotextile fabrics in construction projects. As outlined above, geogrids and geotextile fabrics serve their own different respective purposes. And, in many cases, geogrids and geotextile fabrics are installed together. To better help eliminate installation cost and confusion, there are commercially available products that combine geogrids with geotextile fabrics. These combination geogrid/geotextile fabric products may be generally referred to as geocomposites. 
    
    
     
       DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure. 
         FIG. 1  illustrates a woven geotextile fabric with an integrated geotextile grid according to an exemplary embodiment in which the yarns are integrally woven together in a single step or operation on a weaving machine to thereby provide the woven geotextile fabric and its integrated geotextile grid. 
         FIG. 2  is a side view of the woven geotextile fabric shown in  FIG. 1 , and illustrating cross machine direction rib yarns, cross machine direction single end field yarns, and machine direction single end field yarns according to an exemplary embodiment. 
         FIG. 3  is a side view of the woven geotextile fabric shown in  FIG. 1 , and illustrating machine direction rib yarns, machine direction single end field yarns, and cross machine direction single end field yarns according to an exemplary embodiment. 
         FIG. 4  is a process flow chart representing an exemplary manufacturing process or method according to exemplary embodiments in which yarns are integrally woven together in a single step or operation on a weaving machine to thereby provide a woven geotextile fabric having an integrated geotextile grid. 
     
    
    
     Corresponding reference numerals indicate corresponding (though not necessarily identical) parts throughout the several views of the drawings. 
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 
     As recognized by the inventors hereof, commercially available geocomposites are manufactured from two distinct products or components, i.e., a geotextile fabric and a geogrid. Conventional geocomposites may be made by first separately manufacturing the geotextile fabric and geogrid as distinct products in separate manufacturing steps or processes. Then, the distinct geotextile fabric and geogrid products may be attached (e.g., laminated, glued, heat bonded, mechanical fastened, etc.) to each other in an additional manufacturing step or process to thereby provide the geocomposite. 
     After recognizing the above, the inventors hereof have developed and disclosed herein exemplary embodiments of woven geotextile fabrics with integrated geotextile grids or geogrids. As disclosed herein, the yarns predetermined (e.g., produced, prepared, etc.) for the woven geotextile fabric and its integrated geotextile grid may be integrally woven together in a single step or operation on a weaving machine to thereby provide the woven geotextile fabric and its integrated geotextile grid. Unlike conventional methods and processes, exemplary embodiments disclosed herein do not require an additional conventional manufacturing step or operation of physically attaching (e.g., laminating, gluing, heating to bond the layers together, mechanical fastening, etc.) a separately manufactured geotextile fabric to a separately manufactured geogrid product. 
     Exemplary embodiments disclosed herein include woven geotextile fabrics with integrated geotextile grids that may perform as well as conventional geocomposites that are manufactured from two separate or distinct components, i.e., a geogrid and a separate geotextile fabric where the geogrid is physically attached separately to the geotextile fabric. The inventors hereof have determined that woven geotextile fabrics with integrated geotextile grids (e.g., woven geotextile fabric  100  shown in  FIGS. 1, 2, and 3 , etc.) made or manufactured by integrally weaving the yarns together (e.g., in a single step or operation on a weaving machine) can serve the same or similar purposes and achieve the same or similar results as a conventional two-component geocomposite. 
     For the purpose of description, the reinforced areas of the fabric are referred to herein as ribs. Also for the purpose of description, the fabric areas between the ribs are referred to herein as the field of the fabric or simply the field. 
     The inventors hereof have determined that machine direction rib yarns (e.g.,  128  in  FIG. 3 , etc.) may be inserted during the weaving process in a manner to create the machine direction ribs (e.g.,  108  in  FIG. 1 , etc.). The ribs may be woven into the field of the fabric (e.g.,  112  in  FIG. 1 , etc.) in a manner that allows the yarns to be a permanent and integral part of the overall fabric (e.g.,  100  in  FIGS. 1 and 2 , etc.). The yarns for the machine direction ribs may be woven at intermittent junctions so as to allow the yarns for the ribs to be woven with very little crimp. This may advantageously allow the machine direction ribs to perform at the same or comparable strength as similar machine direction ribs in a geogrid. 
     The cross machine direction ribs (e.g.,  116  in  FIG. 1 , etc.) may be placed into the fabric by modifying the end count of the weaving machine during the insertion of the cross machine direction rib yarns (e.g.,  120  and  124  in  FIG. 2 , etc.). 
     The yarns (e.g.,  124  in  FIG. 2 , etc.) used for the cross machine direction ribs (e.g.,  116  in  FIG. 1 , etc.) may generally be high tenacity PET (polyethylene terephthalate) filament yarns. The yarns (e.g.,  128  in  FIG. 3 , etc.) used for the machine direction ribs (e.g.,  108  in  FIG. 1 , etc.) may also generally be high tenacity PET (polyethylene terephthalate) filament yarns. Alternatively, the machine direction rib yarns and the cross machine direction rib yarns may be made from other substances and materials that provide high tenacity yarns, such as nylon, polypropylene, polyethylene, aramids, high molecular weight polyethylene (UHMWPE), fiberglass, basalt, etc. Examples of high tenacity yarns include yarns having a tenacity within a range from 6.5 grams per denier up to 40 grams per denier, yarns with a tenacity less than 6.5 grams per denier (e.g., 6 grams per denier, at least 4.5 grams per denier, etc.), yarns with a tenacity more than 40 grams per denier. 
     In addition, the machine direction rib yarns and the cross machine direction rib yarns do not have to be made from the same materials. For example, the machine direction rib yarns may be made from a first material different than a second material from which the cross machine direction rib yarns are made. Also by way of example, each machine direction rib yarn does not necessarily have to be made of the same material as each other machine direction rib yarn in all embodiments. Likewise, each cross machine direction rib yarn does not necessarily have to be made of the same material as each other cross machine direction rib yarn in all embodiments. 
     The field of the fabric may be woven using slit tape yarns, fibrillated yarns, and/or monofilament yarns. 
     Yarn profiles may be oval, round, trilobal, multilobal, triangular, rectangular, non-circular, non-rectangular, and/or other cross-sectional shapes, geometries, profiles, etc. End counts of these yarns may vary to achieve a predetermined, satisfactory or proper water flow and sediment retention values as required for the particular end use. Also, each yarn does not necessarily have the same configuration (e.g., tensile strength, yarn type, etc.), same cross-sectional shape or profile, and/or same size (e.g., denier, diameter, thickness, etc.) as each other yarn in all embodiments. 
     Exemplary embodiments may provide a one piece fabric comprising at least two yarns types in the machine direction and at least two yarn types in the cross machine direction. For example, the fabric may include at least two yarns (one for the field and one for the rib) in the machine direction and at least two yarns (one for the field and one for the rib) in the cross machine direction. 
     The end count or density of the yarns in the field may be different than the end count or density of the yarns in the ribs. The end count of the rib yarns may greater than the end count of the field yarns in exemplary embodiments. For example, the end count of the rib yarns may be at least one or more times (e.g., 1.1 times., 20 times, within a range from 1.1. to 20 times, more than 20 times, etc.) than the end count of the field yarns in exemplary embodiments. By way of further example,  FIG. 2  illustrates the cross machine direction rib yarns  120  having an end count per inch that is three times the end count per inch of the cross machine direction single end field yarns  124 . Also, for example,  FIG. 3  illustrates the machine direction rib yarns  128  having an end count per inch that is three times the end count per inch of the machine direction single end field yarns  104 . 
     Alternative embodiments may be configured differently, such as including cross machine direction rib yarns having an end count per inch that is less than or more than three times (e.g., less than 1.1 times, more than 20 times, greater than 1.1 but less than 3, within a range from 1.1 to 3, within a range from 3 to 20, etc.) the end count per inch of the cross machine direction single end field yarns and/or such as including machine direction rib yarns having an end count per inch that is less than or more than three times (e.g., less than 1.1 times, more than 20 times, greater than 1.1 but less than 3, within a range from 1.1 to 3, within a range from 3 to 20, etc.) the end count per inch of the machine direction single end field yarns. Also, the cross machine direction rib yarns and machine direction rib yarns do not have to have the same end counts (e.g., three times, etc.) as respectively compared to the cross machine direction single end field yarns and machine direction single end field yarns. For example, the end count of the cross machine direction rib yarns may be X times the end count of the cross machine direction single end field yarns, whereas the end count of the machine direction rib yarns may be Y times the end count of the machine direction single end field yarns where Y is greater than or less than X. 
     As disclosed for exemplary embodiments herein, the inventors hereof have determined a manner to change density of the cross machine direction yarns (e.g., at will, etc.) during the weaving process while introducing a plurality (e.g., at least 2, up to 8, between 2 to 8, more than 8, etc.) of different cross machine direction yarns as needed. As a result, exemplary embodiments disclosed herein may advantageously provide fabrics that resemble and/or have similar performance as conventional geocomposites while not requiring a secondary attachment step or operation after fabric formation during the weaving process. 
     With reference to the figures,  FIGS. 1, 2, and 3  illustrate an exemplary embodiment of a woven geotextile fabric with an integrated geotextile grid or geogrid  100  embodying one or more aspects of the present disclosure. The woven geotextile fabric  100  includes machine direction rib yarns  128  ( FIG. 3 ) that are inserted during the weaving process in a manner to create the machine direction ribs  108  ( FIG. 1 ). 
     The machine direction ribs  108  may be woven into the field  112  of the fabric  100  in a manner that allows the machine direction rib yarns  128  to be a permanent and integral part of the overall fabric  100 . The yarns  128  for the machine direction ribs  108  may be woven at intermittent junctions so as to allow the yarns  128  for the machine direction ribs  108  to be woven with very little crimp. This advantageously may allow the machine direction ribs  108  to perform at a same or comparable strength as similar ribs in a geogrid. 
     The cross machine direction ribs  116  may be placed into the fabric  100  by modifying the end count of the weaving machine during the insertion of the cross machine direction rib yarns  120 . For example,  FIG. 2  illustrates the cross machine direction rib yarns  120  having an end count per inch that is three times (e.g., end count of 3Y per inch, etc.) the end count per inch of the cross machine direction single end field yarns  124 . Alternatively, the end count of the cross machine direction rib yarns  120  may be higher or lower than three times (e.g., less than 1.1 times, more than 20 times, greater than 1.1 but less than 3, within a range from 1.1 to 3, within a range from 3 to 20, etc.) the end count of the cross machine single end field yarns  124  in other exemplary embodiments. 
       FIG. 3  illustrates the machine direction rib yarns  128  having an end count per inch that is three times (e.g., end count of 3Y per inch, etc.) the end count per inch of the machine direction single end field yarns  104 . Alternatively, the end count of the machine direction rib yarns  128  may be higher or lower than three times (e.g., less than 1.1 times, more than 20 times, greater than 1.1 but less than 3, within a range from 1.1 to 3, within a range from 3 to 20, etc.) the end count of the machine direction single end field yarns  104  in other exemplary embodiments. 
     The cross machine direction rib yarns  120  used for the cross machine direction ribs  116  may generally be high tenacity PET (polyethylene terephthalate) filament yarns. The machine direction rib yarns  128  ( FIG. 3 ) used for the machine direction ribs  108  may also generally be high tenacity PET (polyethylene terephthalate) filament yarns. But in other exemplary embodiments, the machine direction rib yarns  128  and/or the cross machine direction rib yarns  120  may be made from other substances and materials that provide high tenacity yarns, such as nylon, polypropylene, polyethylene, aramids, high molecular weight polyethylene (UHMWPE), fiberglass, basalt, etc. Examples of high tenacity yarns may include yarns having a tenacity within a range from 6.5 grams per denier up to 40 grams per denier, yarns with a tenacity less than 6.5 grams per denier (e.g., 6 grams per denier, at least 4.5 grams per denier, etc.), yarns with a tenacity more than 40 grams per denier. 
     The field  112  of the fabric  100  may comprise woven using slit tape yarns, fibrillated yarns, and/or monofilament yarns. 
     Profiles for the machine direction field yarns  104 , cross machine direction field yarns  124 , cross machine direction rib yarns  120 , and machine direction rib yarns  128  may be oval, round, trilobal, multilobal, triangular, rectangular, non-circular, among other cross-sectional shapes, geometries, profiles, etc. In addition, the machine direction field yarns  104 , cross machine direction field yarns  124 , cross machine direction rib yarns  120 , and machine direction rib yarns  128  may have the same, similar, or different profiles. 
     For example,  FIGS. 2 and 3  illustrate the rectangular profiles of the cross machine direction field yarns  124  and the machine direction field yarns  104 , respectively.  FIGS. 2 and 3  also illustrate the multilobal profiles of the cross machine direction rib yarns  120  and machine direction rib yarns  128 , respectively. Alternatively, each cross machine direction field yarn  124  and each machine direction field yarn  104  does not necessarily have the same profile and/or the same size (e.g., denier, diameter, thickness, etc.) as each other cross machine direction field yarn  124  and each machine direction field yarn  104 . Likewise, each cross machine direction rib yarn  120  and each machine direction rib yarn  128  does not necessarily have the same profile and/or the same size (e.g., denier, diameter, thickness, etc.) as each other cross machine direction rib yarn  120  and each machine direction rib yarn  128 . 
     End counts of the machine direction field yarns  104 , cross machine direction field yarns  124 , cross machine direction rib yarns  120 , and machine direction rib yarns  128  may vary to achieve a predetermined, satisfactory, and/or proper water flow and sediment retention values as required for the particular end use. 
     By way of example, one exemplary embodiment of the woven geotextile fabric  100  included machine direction rib yarns  128  and cross machine direction rib yarns  120  comprising polyethylene terephthalate filament yarns having a denier of about 18,000, a generally round cross-sectional shape, a tenacity within a range from at least about 6.5 grams per denier up to at least about 40 grams per denier. The machine direction rib yarns  128  had an end count of 24 per inch, whereas the cross machine direction rib yarns  120  had an end count of 18 per inch. Continuing with this example, the machine direction field yarns  104  comprised polypropylene slit tape yarns having a denier of about 800, a generally rectangular cross-sectional shape, a tenacity less than the machine direction rib yarns  128 , and an end count of 16 per inch. Also in this example, the cross machine direction field yarns  124  comprised polypropylene slit tape yarns having a denier of about 2100, a generally rectangular cross-sectional shape, a tenacity less than the cross machine direction rib yarns  120 , and an end count of 10 per inch. 
     For illustrative purposes, a sample geotextile fabric was produced that achieves  200  pounds of tensile strength (ASTM D4632) in both the machine direction and the cross machine direction. This sample geotextile fabric included machine direction polypropylene slit tape yarns having a denier of about 800, a generally rectangular cross-sectional shape, and an end count of 16 per inch. This sample geotextile fabric also included cross machine direction polypropylene slit tape yarns having a denier of about 210, a generally rectangular cross-sectional shape, and an end count of 10 per inch. This sample geotextile fabric was tested with results for strength listed in Table 1 below. 
     The same geotextile fabric was then manufactured with introduction of high tenacity PET filament yarns having a denier of about 18,000, a generally round cross-sectional shape, and tenacity within a range from at least about 6.5 grams per denier up to at least about 40 grams per denier in both the machine and cross machine directions. These high tenacity PET yarns were inserted during weaving in a manner that created an integrated geotextile grid or ribbed geogrid within the 200 pound geotextile fabric. For example, two machine direction rib yarns comprising PET filament yarns having 18,000 denier each were inserted every inch in the machine direction at 1.5 times the density of the ends of the field yarns forming the geotextile fabric. At the same time, two cross machine direction rib yarns comprising PET filament yarns having 18,000 denier were inserted every inch in the cross machine direction at 2 times the density of the field yarns forming the geotextile fabric. The machine direction rib yarns  128  had an end count of 24 per inch, whereas the cross machine direction rib yarns  120  had an end count of 18 per inch. 
     The result was a 200 pound geotextile fabric with an integrated geogrid, which was manufactured in a single step or process during the weaving process. Results for the same tests can be viewed in Table 2. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Test Results Typical Woven 200 pound Geotextile Fabric 
               
            
           
           
               
               
               
               
            
               
                 Property 
                 Test Method 
                 Machine Direction Value 
                 Cross Machine Direction Value 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Tensile Strength (Grab) 
                 ASTM D4632 
                 220 
                 lbs 
                 250 
                 lbs 
               
               
                 Wide Width Tensile 
                 ASTM D4595 
                 1560 
                 lbs/ft 
                 2200 
                 lbs/ft 
               
               
                 Wide Width @ 2% Strain 
                 ASTM D4595 
                 355 
                 lbs/ft 
                 860 
                 lbs/ft 
               
               
                 Wide Width @ 5% Strain 
                 ASTM D4595 
                 710 
                 lbs/ft 
                 1675 
                 lbs/ft 
               
               
                   
               
            
           
         
       
     
     
       
         
           
               
             
               
                 TABLE 2 
               
             
            
               
                   
               
               
                 Test Results Woven 200 pound Geotextile Fabric with Integrated Geogrid 
               
            
           
           
               
               
               
               
            
               
                 Property 
                 Test Method 
                 Machine Direction Value 
                 Cross Machine Direction Value 
               
               
                   
               
            
           
           
               
               
               
               
               
               
            
               
                 Tensile Strength (Grab) 
                 ASTM D4632 
                 715 
                 lbs 
                 620 
                 lbs 
               
               
                 Wide Width Tensile 
                 ASTM D4595 
                 7440 
                 lbs/ft 
                 6885 
                 lbs/ft 
               
               
                 Wide Width @ 2% Strain 
                 ASTM D4595 
                 1245 
                 lbs/ft 
                 2080 
                 lbs/ft 
               
               
                 Wide Width @ 5% Strain 
                 ASTM D4595 
                 2540 
                 lbs/ft 
                 3940 
                 lbs/ft 
               
               
                   
               
            
           
         
       
     
     As shown by a comparison of Tables 1 and 2, the woven 200 pound geotextile fabric with the integrated geogrid has considerably higher machine direction and cross direction values for tensile strength (grab), wide width tensile, wide width at 2% strain, and wide width at 5% strain as compared to the conventional 200 pound geotextile fabric. Accordingly, the integrated geogrid significantly increased the tensile strength of the woven 200 pound geotextile fabric. 
     The machine direction rib yarns and the cross machine direction field yarns are preferably thicker than the machine direction field yarns and the cross machine direction field yarns. With the greater thickness of the rib yarns, the integrated geotextile grid cooperatively defined by the machine direction rib yarns and the cross machine direction rib yarns is therefore thicker than the fabric areas cooperative defined by the machine direction field yarns and the cross machine direction field yarns. Advantageously, the thicker integrated geotextile grid may thus have a higher pullout resistance (e.g., vertically and/or horizontally, etc.) in soil than the thinner fabric areas cooperative defined by the machine direction field yarns and the cross machine direction field yarns. 
     By way of example, an exemplary embodiment of a woven geotextile fabric having an integrated geotextile grid may be placed generally horizontally across a layer of soil and/or aggregate and within a vertical retaining wall. Soil and/or aggregate may become entangled or enmeshed within the relatively thick integrated geotextile grid, which may provide significant resistance to prevent or inhibit the retaining wall from toppling over. In which case, the integrated geotextile grid may help hold the retaining wall upright, and the soil and/or aggregate that is retained within the integrated geotextile grid inhibits or prevents the integrated geotextile grid from being easily pulled out. 
       FIG. 4  is a process flow chart representing an exemplary manufacturing process or method  240  of making a woven geotextile fabric (e.g., fabric  100  in  FIGS. 1, 2, and 3 , etc.) with an integrated geotextile grid according to exemplary embodiments. The woven geotextile fabric and its integrated geotextile grid may be made by a weaving machine in a single step or operation  252  without requiring the additional conventional steps or operations of manufacturing the woven geotextile fabric separately from the integrated geotextile grid and thereafter physically attaching (e.g., laminating, gluing, heat bonding, etc.) the previously manufactured geotextile fabric separately to the previously manufactured geogrid product as conventionally done. As disclosed herein, the yarns for the woven geotextile fabric and its integrated geotextile grid are integrally woven together (e.g., in a single weaving step or operation on a weaving machine, etc.), such that neither the geotextile fabric nor its integrated geotextile grid are manufactured separately from each other at different times and/or via different process as distinct products that must thereafter be subsequently joined together. As also disclosed herein, the woven geotextile fabric and its integrated geotextile grid are configured such that the yarn type and yarn density changes in both the machine direction and the cross machine direction in exemplary embodiments. 
     Generally, the method  240  includes three operations or steps labeled as yarn production  244 , yarn preparation  248 , and weaving  252  as shown in  FIG. 4 . At the yarn production step or operation  244 , yarn is produced or manufactured. By way of example only, the yarn preparation step or operation  248  may include beaming. Or, for example, the yarn preparation step or operation  248  may include presenting yarn to a weaving machine, commonly called a loom, directly from a creel, such that beaming is bypassed and there is no beaming required. Accordingly, aspects of the present disclosure are not limited to any particular way of how yarn gets into the loom or weaving machine. 
     At the third step or operation  252 , the weaving machine or loom is used for weaving. Aspects of the present disclosure are not limited to and are not dependent on any particular type of weave. 
     Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail. In addition, advantages and improvements that may be achieved with one or more exemplary embodiments of the present disclosure are provided for purpose of illustration only and do not limit the scope of the present disclosure, as exemplary embodiments disclosed herein may provide all or none of the above mentioned advantages and improvements and still fall within the scope of the present disclosure. 
     Specific dimensions, specific materials, and/or specific shapes disclosed herein are example in nature and do not limit the scope of the present disclosure. The disclosure herein of particular values and particular ranges of values for given parameters are not exclusive of other values and ranges of values that may be useful in one or more of the examples disclosed herein. Moreover, it is envisioned that any two particular values for a specific parameter stated herein may define the endpoints of a range of values that may be suitable for the given parameter (i.e., the disclosure of a first value and a second value for a given parameter can be interpreted as disclosing that any value between the first and second values could also be employed for the given parameter). For example, if Parameter X is exemplified herein to have value A and also exemplified to have value Z, it is envisioned that parameter X may have a range of values from about A to about Z. Similarly, it is envisioned that disclosure of two or more ranges of values for a parameter (whether such ranges are nested, overlapping or distinct) subsume all possible combination of ranges for the value that might be claimed using endpoints of the disclosed ranges. For example, if parameter X is exemplified herein to have values in the range of 1-10, or 2-9, or 3-8, it is also envisioned that Parameter X may have other ranges of values including 1-9, 1-8, 1-3, 1-2, 2-10, 2-8, 2-3, 3-10, and 3-9. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. For example, when permissive phrases, such as “may comprise”, “may include”, and the like, are used herein, at least one embodiment comprises or includes the feature(s). As used herein, the singular forms “a”, “an” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
     When an element or layer is referred to as being “on”, “engaged to”, “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to”, “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     The term “about” when applied to values indicates that the calculation or the measurement allows some slight imprecision in the value (with some approach to exactness in the value; approximately or reasonably close to the value; nearly). If, for some reason, the imprecision provided by “about” is not otherwise understood in the art with this ordinary meaning, then “about” as used herein indicates at least variations that may arise from ordinary methods of measuring or using such parameters. For example, the terms “generally”, “about”, and “substantially” may be used herein to mean within manufacturing tolerances. 
     Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments. 
     Spatially relative terms, such as “inner,” “outer,” “beneath”, “below”, “lower”, “above”, “upper” and the like, may be used herein for ease of description to describe one element or feature&#39;s relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements, intended or stated uses, or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.