Patent Publication Number: US-2021180631-A1

Title: Polymeric fastener

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 62/533,280 filed on Jul. 17, 2017. The entire disclosure of the above referenced application is incorporated herein by reference. 
    
    
     FIELD 
     The subject disclosure generally relates to fasteners such as those used in the construction industry and more particularly to fasteners such as nails and staples. 
     BACKGROUND 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Fasteners are commonly used in the construction industry to fasten buildings together. Examples of fasteners include nails and staples. Such fasteners are typically made of a single material such as steel or some other type of metal. However, there are some low force requirement fasteners where the single material forming the fastener is a non-ferrous material, such as plastic. Known fasteners made of a non-ferrous material are not suitable for the construction industry because they typically do not have sufficient strength to hold building components together. 
     SUMMARY 
     This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features. 
     The present disclosure is directed to improved polymeric fasteners. In accordance with one aspect of the present disclosure, a fastener is provided with an internal strengthening core having a first thickness and an outer layer disposed about the internal strengthening core. The outer layer has a second thickness that is at least half as thick as the first thickness of the internal strengthening core. The outer layer is made of a first material that is a polymeric material and the internal strengthening core is made of a second material that is different than the first material of the outer layer. 
     In accordance with another aspect of the present disclosure, a nail-like fastener is provided, which includes a shank, a head at one end of the shank, and a point at an opposite end of the shank. The shank and the head are made of a first material and a second material. The first material comprises at least 50 percent of the material in the shank and the head of the nail-like fastener. The first material is a polymeric material and the second material is different than the first material and is stronger than the first material. 
     In accordance with another aspect of the present disclosure, a staple-like fastener is provided, which includes a bridge portion that extends between first and second ends, a first leg that extends from the first end of the bridge portion, and a second leg that extends from the second end of the bridge portion. The first and second legs are parallel to one another and are transverse to the bridge portion. The bridge portion and the first and second legs are made of a first material and a second material. The first material comprises at least 50 percent of the material in the bridge portion and the first and second legs of the staple-like fastener. The first material is a polymeric material and the second material is different than the first material and is stronger than the first material. 
    
    
     
       BRIEF DESCRIPTION OF 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. 
       Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
         FIG. 1  is a side cross-sectional view of an exemplary polymeric fastener constructed in accordance with the subject disclosure where the polymeric fastener is a nail formed of a reinforced polymeric material; 
         FIG. 2  is a side cross-sectional view of another exemplary polymeric fastener constructed in accordance with the subject disclosure where the polymeric fastener is a nail formed of an outer layer of polymeric material and an internal strengthening core that is made of a different material; 
         FIG. 3  is a side cross-sectional view of an exemplary polymeric fastener constructed in accordance with the subject disclosure where the polymeric fastener is a staple formed of a reinforced polymeric material; and 
         FIG. 4  is a side cross-sectional view of another exemplary polymeric fastener constructed in accordance with the subject disclosure where the polymeric fastener is a staple formed of an outer layer of polymeric material and an internal strengthening core that is made of a different material. 
     
    
    
     DETAILED DESCRIPTION 
     Example embodiments will now be described more fully with reference to the accompanying drawings. 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. 
     The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. 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. 
     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 subject disclosure provides for composite fasteners  20 ,  120 ,  220 ,  320  that are made of at least two different materials. At least one of the two materials is a polymeric material. The other material can be a different polymeric material, or alternatively, a material that is not a polymer. In the embodiments shown in  FIGS. 1 and 2 , the shape of the fasteners  20 ,  120  is that of a typical construction framing nail for wood construction buildings. In the embodiments shown in  FIGS. 3 and 4 , the shape of the fastener  220 ,  320  is that of a typical staple-like fastener, such as may be used in the fastening of roofing felt, roof shingles, house wrap, and other similar substrate products. 
     Referring to  FIG. 1 , a first exemplary fastener  20  is illustrated, which has a nail-like arrangement. The fastener  20  includes a shank  26 , a head  28  at one end of the shank  26 , and a point  30  at an opposite end of the shank  26 . The fastener  20  includes a first material  22  that is a polymeric material, such as a resin based polymeric composition like high density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), or other similar polymeric materials. The first material  22  is infused with a second material  24  that acts as a strengthening substance. To accomplish this function, the second material  24  is stronger than the first material  22 . For example, high density polyethylene (HDPE) can have strength issues, which can be enhanced by adding various types of fibers, glass filling, metal filings, nano-spheres, and/or other material ingredients. 
     In the example shown in  FIG. 1 , the second material  24  is scattered throughout the first material  22 , which acts as a base material. In other words, the first material  22  forms at least 50 percent of the material volume in the shank  26  and head  28  of the fastener  20 . The second material  24  may be any one of several nano-spheroid materials such as glass, ceramics, metals, plastics, polycarbonates, or a combination thereof. The second material  24  may be a fibrous material such as fabrics, polyesters, Kevlar, etc. Fibrous materials may also be in the form of relatively straight fiber stands of various lengths and/or fibers with wiry interlocking entanglement characteristics. 
     A preferred optimum ratio of the first material  22  to the second material  24  has been found to be from 1:0.059 to 1:0.154 (expressed as volume of first material  22 : volume of second material  24 ). Stated another way, the second material  24  comprises at that least 4.5 percent of the volume of the total composite (i.e., the total volume of the fastener  20 ) and optimally the second material  24  comprises from 5.9 percent to 15.4 percent of the volume of total composite (i.e., the total volume of the fastener  20 ). 
     In one alternative embodiment, the second material  24  may be comprised of at least two ingredients which have a specific ratio between them to provide strengthening capabilities and other properties that the first material  22  does not possess. For instance, high density polyethylene (HDPE) is not naturally ozone resistant and will degrade over time when exposed to sunlight. Adding a second ingredient such as carbon will provide ozone resistance. In accordance with this embodiment, the second material  24  is comprised of at least two ingredients which are combined into the composite at a pre-defined ratio to each other. A preferred optimum ratio of the ozone resistant ingredient(s) to the strengthening ingredient(s) has been found to be from 45:55 to 40:60 (expressed as volume of the ozone resistant ingredient(s): volume of the strengthening ingredient(s)). 
     Adding ingredients into the first material  22  must be considered carefully because the balance of ingredients in the second material  24  can create a composite that has compromised properties compared to the first material  22 . Testing has shown that benefits in ozone resistance and improved strength can be accomplished with high density polyethylene (HDPE) as the first material  22 , while a combination of carbon dust for ozone resistance and fibers for strengthening greatly improve the capabilities and performance of the polymeric fasteners  20 ,  120 ,  220 ,  320 . ft should be appreciated that the ratios listed above are not limited to the exemplary fastener  20  shown in  FIG. 1  and apply equally to the fasteners  120 ,  220 ,  320  shown in  FIGS. 2-4 . 
     Referring to  FIG. 2 , a second exemplary fastener  120  is illustrated, which again has a nail-like arrangement. The fastener  120  includes a shank  126 , a head  128  at one end of the shank  126 , and a point  130  at an opposite end of the shank  126 . The head  128  and shank  126  of the fastener  120  have an internal strengthening core  132  and an outer layer  134  that is disposed about the internal strengthening core  132 . The outer layer  134  is made of a first material  122 . The first material  122  forming the outer layer  134  is a polymeric material, such as a resin based polymeric composition like high density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), or other similar polymeric materials. The internal strengthening core  132  is made of a second material  124  that is stronger than the first material  122  forming the outer layer  134 . The second material  124  forming the internal strengthening core  132  is a carbon fiber material, a metal wire-like material insert, a hardened resin material, a sintered metal, or other reinforced core material. The internal strengthening core  132  has a first thickness  136  and the outer layer  134  has a second thickness  138  that is at least half as thick as the first thickness  136  of the internal strengthening core  132 . As a result, it should be appreciated that the first material  122  forms at least 50 percent of the material volume in the shank  126  and head  128  of the fastener  120 , which distinguishes the outer layer  134  from a thin coating applied to a conventional nail. In the embodiment illustrated in  FIG. 2 , the fastener  120  also has retention features  140  that extend outwardly from the shank  126 . The retention features  140  in the illustrated example are made of the first material  122 . 
     The fasteners  20 ,  120  illustrated in  FIGS. 1 and 2  can be made available in many shank diameters and lengths depending upon the construction requirements. The fasteners  20 ,  120  disclosed in  FIGS. 1 and 2  may also be provided with a different head design (not shown) to enhance the function of the polymeric fasteners  20 ,  120  compared to a traditional nail formed from a wire drawn system. The head  28 ,  128  of polymeric fasteners  20 ,  120  is not limited to certain shape, size, and/or design details, which limit such characteristics of wire drawn fasteners due to the manufacturing operations used to form wire drawn fasteners. 
     Polymeric fasteners  20 ,  120  also have an advantage over traditional wire drawn fasteners in that the typical limitations on the design of retention features  140  are not present because of the formation methods available to polymeric fasteners  20 ,  120 . For example, enhanced ring shanks  140  of a myriad of design shapes can be formed on the shank  26  of polymeric fasteners  20 ,  120 . These retention features  140  would be otherwise impossible to form on a traditional wire drawn fastener shank due to the manufacturing operations used to from such wire drawn fasteners. 
     Referring to  FIG. 3 , a third exemplary fastener  220  is illustrated, which has a staple-like arrangement. The fastener  220  includes a bridge portion  242 , a first leg  244  that extends from a first end of the bridge portion  242 , and a second leg  246  that extends from a second end of the bridge portion  242  that is opposite the first end of the bridge portion  242 . The first and second legs  244 ,  246  are substantially parallel to one another and are substantially transverse to the bridge portion  242 . The fastener  220  includes a first material  222  that is a polymeric material, such as a resin based polymeric composition like high density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), or other similar polymeric materials. The first material  222  is infused with a second material  224  that acts as a strengthening substance. To accomplish this function, the second material  224  is stronger than the first material  222 . 
     In the example shown in  FIG. 3 , the second material  224  is scattered throughout the first material  222 , which acts as a base material. In other words, the first material  222  forms at least 50 percent of the material volume in the bridge portion  242  and the first and second legs  244 ,  246  of the fastener  220 . The second material  224  may be any one of several nano-spheroid materials such as glass, ceramics, metals, plastics, polycarbonates, or a combination thereof. The second material  224  may be a fibrous material such as fabrics, polyesters, Kevlar, etc. Fibrous materials may also be in the form of relatively straight fiber stands of various lengths and/or fibers with wiry interlocking entanglement characteristics. 
     Referring to  FIG. 4 , a fourth exemplary fastener  320  is illustrated, which again has staple-like arrangement. The fastener  320  includes a bridge portion  342 , a first leg  344  that extends from a first end of the bridge portion  342 , and a second leg  346  that extends from a second end of the bridge portion  342  that is opposite the first end of the bridge portion  342 . The first and second legs  344 ,  346  are substantially parallel to one another and are substantially transverse to the bridge portion  342 . The bridge portion  342  and the first and second legs  344 ,  346  of the fastener  320  have an internal strengthening core  332  and an outer layer  334  that is disposed about the internal strengthening core  332 . The outer layer  334  is made of a first material  322 . The first material  322  forming the outer layer  334  is a polymeric material, such as a resin based polymeric composition like high density polyethylene (HDPE), ultra high molecular weight polyethylene (UHMWPE), or other similar polymeric materials. The internal strengthening core  332  is made of a second material  324  that is stronger than the first material  322  forming the outer layer  334 . The second material  324  forming the internal strengthening core  332  is a carbon fiber material, a metal wire-like material insert, a hardened resin material, a sintered metal, or other reinforced core material. The internal strengthening core  332  has a first thickness  336  and the outer layer  334  has a second thickness  338  that is at least half as thick as the first thickness  336  of the internal strengthening core  332 . As a result, it should be appreciated that the first material  322  forms at least 50 percent of the material volume in the bridge portion  342  and the first and second legs  344 ,  346  of the fastener  320 , which distinguishes the outer layer  334  from a thin coating applied to a conventional staple. 
     Those skilled in the art will appreciate the challenges fasteners present, in that extensive manufacturing development time and effort is required in order to achieve acceptable performance characteristics for use in the construction industry. Manufacturing methods for the polymeric fasteners  20 ,  120 ,  220 ,  320  described above will vary from one another depending upon which outer layer material is used and which strengthening materials are used in the fabrication of the fasteners  20 ,  120 ,  220 ,  320 . 
     Outer layer materials (i.e., the first material  22 ,  122 ,  222 ,  322 ) such as polymers, high density polyethylene (HDPE), and other similar materials and/or resin based materials may be injected, compression formed, cast, or epoxy mixed and poured into a representative formed fastener shaped mold cavity. The outer layer material may be formed over an inner insert strengthening material (i.e., the second material  24 ,  124 ,  224 ,  324 ) and/or the outer layer material may be infused (i.e., impregnated) with the strengthening material so as to evenly distribute the strengthening material throughout the outer layer material. 
     After initial forming of the polymeric fasteners  20 ,  120 ,  220 ,  320 , any one of several various secondary operations may be required depending upon the first material  22 ,  122 ,  222 ,  322  used as the outer layer material. A casting method may include a parting line trimming operation. In addition, a post forming hardening operation may be performed. One or more catalysts may be used to cure the outer layer material and/or the strengthening material. An oven post curing operation and/or an ultraviolet light curing operation may be utilized to develop appropriate structural and/or mechanical properties of the fasteners  20 ,  120 ,  220 ,  320 . A pointing operation may be required to apply the preferred shape to one end of the fasteners  20 ,  120 ,  220 ,  320  for desired penetration characteristics depending on the type of substrates being fastened. 
     Polymeric fasteners  20 ,  120 ,  220 ,  320  offer additional benefits in that they can be made of rust and corrosion resistant materials. In sand and beach construction applications, polymeric fasteners can provide salt-water corrosion resistance. Other corrosive environments can be serviced as well with specially composed polymeric fasteners. In addition to salt-water environments, other contaminates can be resisted with appropriately composed polymeric material fasteners. 
     Still other polymeric fasteners can be formed to be electrically non-conductive to prevent tracking and/or sparking in high voltage construction applications. In contrast, a preferred amount of electrically conductive material such as graphite or graphene can be infused into the outer layer material so that a specific electrical conductivity can be establish for specified grounding and/or anti-static construction fastener applications. 
     In most applications, it will be desirable for users to install the polymeric fasteners  20 ,  120 ,  220 ,  320  via delivery systems powered by pneumatics, hydraulics, or other mechanical systems. Specially designed and/or modified delivery systems can be used depending on the geometry and strength of the polymeric fasteners  20 ,  120 ,  220 ,  320 . 
     An additional benefit of polymeric fasteners  20 ,  120 ,  220 ,  320  is related to the actual weight of the fasteners  20 ,  120 ,  220 ,  320  compared to typical wire drawn fasteners. The polymeric fasteners  20 ,  120 ,  220 ,  320  disclosed herein can be made to be much lighter compared to typical steel fasteners. The polymeric fasteners  20 ,  120 ,  220 ,  320  disclosed herein can be made to have a specific gravity in the range of 0.95-2.0, while steel wire drawn fasteners have a specific gravity in the range of 7.0-8.0, which a factor of at least 600 percent to 700 percent heavier than the polymeric fasteners  20 ,  120 ,  220 ,  320  of the present disclosure. As a result, the shipping cost of raw materials for the polymeric fasteners  20 ,  120 ,  220 ,  320  is dramatically reduced as is the shipping cost of the finished polymeric fasteners  20 ,  120 ,  220 ,  320 . 
     This difference in weight for finished polymeric fasteners  20 ,  120 ,  220 ,  320  provides the added benefit of being able to pack a shipping container with close to 100 percent of its volume being occupied by the polymeric fasteners  20 ,  120 ,  220 ,  320 , instead of being limited by weight before filling out the volume. The net result is more finished polymeric fasteners  20 ,  120 ,  220 ,  320  can be shipped by volume at a reduced shipping weight, which saves shipping cost and increases the amount of fasteners  20 ,  120 ,  220 ,  320  that can be shipped at one time. 
     Those skilled in the art will readily appreciate that there are many more applications for the polymeric fasteners  20 ,  120 ,  220 ,  320  disclosed herein than described in this disclosure. Furthermore, those skilled in the art will also readily appreciate that there are many more materials suitable for use in the formation and fabrication of the polymeric fasteners  20 ,  120 ,  220 ,  320  described herein than have been listed in this disclosure. 
     Many modifications and variations of the present disclosure are possible in light of the above teachings and may be practiced otherwise than as specifically described while within the scope of the appended claims. These antecedent recitations should be interpreted to cover any combination in which the inventive novelty exercises its utility.