Patent Publication Number: US-2022219051-A1

Title: Golf club heads comprising a thermoplastic composite material

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This is a continuation of U.S. patent application Ser. No. 16/949,224, patented as U.S. patent application Ser. No. 11/235,210, filed Oct. 20, 2020, which is a continuation of U.S. patent application Ser. No. 16/252,317, patented as U.S. Pat. No. 10,806,977, filed Jan. 18, 2019, which claims the benefit of priority from U.S. Provisional Patent Nos. 62/619,631 filed 19 Jan. 2018; 62/644,319 filed 16 Mar. 2018; 62/702,996 filed 25 Jul. 2018; 62/703,305 filed 25 Jul. 2018; 62/718,857 filed 14 Aug. 2018; 62/770,000 filed 20 Nov. 2018; and 62/781,509 filed 18 Dec. 2018; the disclosure of each of the above-referenced applications and patents are incorporated by reference in their entirety. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates to a golf club head having one or more components comprising a thermoplastic composite material. 
     BACKGROUND 
     In an ideal club design, the amount of structural mass would be minimized (without sacrificing resiliency) to provide additional discretionary mass that can be strategically positioned to customize club performance. In general, the total of all club head mass is the sum of the structural mass and the discretionary mass. Structural mass generally refers to the mass of the materials that are required to provide the club head with the structural resilience needed to withstand repeated impacts. Structural mass is highly design-dependent, and provides little design control over specific mass distribution. Conversely, discretionary mass is any additional mass (beyond the minimum structural requirements) that may be added to the club head design for the sole purpose of customizing the performance and/or forgiveness of the club. Current golf club heads comprise metallic materials for at least a portion of the structural mass of the club head (for example, in the strike face and/or at least a portion of the rear body). There is a need in the art for alternative designs to golf club heads having structural mass comprising metal, to provide a means for maximizing discretionary weight to maximize club head moment of inertia (MOI) and lower/back center of gravity (CG). 
     While this provided background description attempts to clearly explain certain club-related terminology, it is meant to be illustrative and not limiting. Custom within the industry, rules set by golf organizations such as the United States Golf Association (USGA) or The R&amp;A, and naming convention may augment this description of terminology without departing from the scope of the present application. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic perspective view of a golf club head. 
         FIG. 2A  is a schematic cross-sectional view of a forward portion of the golf club head of  FIG. 1 , taken along line  2 - 2 . 
         FIG. 2B  is a schematic partial cross-sectional view of a forward portion of the golf club head of  FIG. 1 , taken along line  2 - 2 . 
         FIG. 3  is a schematic perspective view of the front and top portions of a golf club head. 
         FIG. 4  is a schematic partial cross-sectional view of a polymeric wall with a plurality of discontinuous fibers embedded within the polymer. 
         FIG. 5  is a schematic perspective view of a molded front body of a golf club head with a sprue and molding gate leading into the front body. 
         FIG. 6  is a reverse view of the front body of  FIG. 5   
         FIG. 7  is a schematic perspective view of the rear portion of a molded front body of a golf club head. 
         FIG. 8  is a schematic illustration of the mold flow for creating the front body of  FIG. 5 , taken at a point of intermediate fill. 
         FIG. 9  is a schematic illustration of the mold flow of  FIG. 8 , taken at a point nearing complete creation of the part. 
         FIG. 10  is a schematic perspective view of the rear portion of a molded front body of a golf club head with a reinforcing mesh embedded within the strike face. 
         FIG. 11  is a schematic cross-sectional view of a first embodiment of the golf club head of  FIG. 10 , taken along line  11 - 11 . 
         FIG. 12  is a schematic cross-sectional view of a second embodiment of the golf club head of  FIG. 10 , taken along line  11 - 11 . 
         FIG. 13  is a schematic cross-sectional view of a third embodiment of the golf club head of  FIG. 10 , taken along line  11 - 11 . 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure generally relates to embodiments of a golf club head having one or more injection molded thermoplastic composite materials incorporated into the club head face and/or body to form a structural aspect of the club head. In doing so, the present designs effect a reduction in structural mass of the head when compared to an all-metal club head of a similar size, shape, and outward appearance. The additional discretionary mass that these designs provide is then available to a club head designer to be strategically placed around the head, for example, to increase the moment of inertia of the club head and/or to alter the relative location of the club head&#39;s center of gravity. 
     Since thermoplastic polymers have considerably lower strengths than most metals used in golf clubs, special attention must be paid to the design, material selection, and reinforcement within polymeric portions to avoid unexpected failure while still maintaining a dynamic response, sound, and feel that is expected by the golfer. 
     Embodiments discussed below further recognize that filled polymers can have anisotropic structural qualities, which are dependent on the typical or average orientation of the embedded, discontinuous fibers. More specifically, a filled polymeric component will generally have greater strength to loads aligned with the longitudinal axis of the embedded fibers, and comparatively less strength to loads applied laterally. Because fiber orientation within a filled polymer is highly dependent on mold flow during the initial part formation, embodiments described below utilize mold and part designs that aid in orienting the embedded fiber along the most likely force/stress propagation paths. 
     “A,” “an,” “the,” “at least one,” and “one or more” are used interchangeably to indicate that at least one of the item is present; a plurality of such items may be present unless the context clearly indicates otherwise. All numerical values of parameters (e.g., of quantities or conditions) in this specification, including the appended claims, are to be understood as being modified in all instances by the term “about” whether or not “about” actually appears before the numerical value. “About” indicates that the stated numerical value allows some slight imprecision (with some approach to exactness in the value; about or reasonably close to the value; nearly). If 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 and using such parameters. In addition, disclosure of ranges includes disclosure of all values and further divided ranges within the entire range. Each value within a range and the endpoints of a range are hereby all disclosed as separate embodiment. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated items, but do not preclude the presence of other items. As used in this specification, the term “or” includes any and all combinations of one or more of the listed items. When the terms first, second, third, etc. are used to differentiate various items from each other, these designations are merely for convenience and do not limit the items. 
     The terms “loft” or “loft angle” of a golf club, as described herein, refers to the angle formed between the club face and the shaft, as measured by any suitable loft and lie machine. 
     The terms “first,” “second,” “third,” “fourth,” and the like in the description and in the claims, if any, are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments described herein are, for example, capable of operation in sequences other than those illustrated or otherwise described herein. Furthermore, the terms “include,” and “have,” and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, device, or apparatus that comprises a list of elements is not necessarily limited to those elements, but may include other elements not expressly listed or inherent to such process, method, system, article, device, or apparatus. 
     The terms “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and the like in the description and in the claims, if any, are used for descriptive purposes with general reference to a golf club held at address on a horizontal ground plane and at predefined loft and lie angles, though are not necessarily intended to describe permanent relative positions. It is to be understood that the terms so used are interchangeable under appropriate circumstances such that the embodiments of the apparatus, methods, and/or articles of manufacture described herein are, for example, capable of operation in other orientations than those illustrated or otherwise described herein. 
     The terms “couple,” “coupled,” “couples,” “coupling,” and the like should be broadly understood and refer to connecting two or more elements, mechanically or otherwise. Coupling (whether mechanical or otherwise) may be for any length of time, e.g., permanent or semi-permanent or only for an instant. 
     Other features and aspects will become apparent by consideration of the following detailed description and accompanying drawings. Before any embodiments of the disclosure are explained in detail, it should be understood that the disclosure is not limited in its application to the details or construction and the arrangement of components as set forth in the following description or as illustrated in the drawings. The disclosure is capable of supporting other embodiments and of being practiced or of being carried out in various ways. It should be understood that the description of specific embodiments is not intended to limit the disclosure from covering all modifications, equivalents and alternatives falling within the spirit and scope of the disclosure. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
     General Club Head Structure 
     Referring to the drawings, wherein like reference numerals are used to identify like or identical components in the various views,  FIGS. 1, 2A, and 2B  schematically illustrate an embodiment of a golf club head  10  that includes a front body portion  12  (“front body  12 ”) and a rear body portion  14  (“rear body  14 ”). The front body  12  and rear body  14  are coupled together to define a substantially enclosed/hollow interior volume  16 , such as shown in  FIGS. 2A and 2B . As is conventional with wood-style heads, the golf club head  10  includes a crown  20  and a sole  22 , and may be generally divided into a heel portion  24 , a toe portion  26 , and a central portion  28  that is located between the heel portion  24  and toe portion  26 . 
     The front body  12  generally includes a strike face  30  that has a forward ball-striking surface  32 , which is intended to impact a golf ball during a conventional swing. In some embodiments, the front body  12  may also include a frame  34  that surrounds and extends rearward from a perimeter  36  of the strike face  30  to provide the front body  12  with a cup-shaped appearance, and may further include a hosel  38  for receiving a golf club shaft or shaft adapter. 
     In a playable, completed club head  10 , the front body  12  and the rear body  14  are integrally coupled at a joint  40 , such as through one or more adhering, bonding, mechanical affixing, welding, or fusing operations. In one particular configuration, such as shown in  FIGS. 2A and 2B , the joint  40  may be a lap joint that maintains an outer surface  42  of the frame  34  is a substantially continuous alignment with an outer surface  44  of the rear body  14 . The lap joint may comprise a bonded interface  46  and a mechanical interface  48 . 
     The bonded interface  46  may be formed when a bond surface  50  of the front body  12  (front bond surface  50 ) abuts and is secured to a mating bond surface  52  of the rear body  14  (rear bond surface  52 ). In the embodiment shown, the front bond surface  50  surrounds and is radially exterior to the rear bond surface  50 , with both surfaces  50 ,  52  being flush with each other and extending in a generally front/back direction. The front bond surface  50  may be coupled to the rear bond surface  52  through any of the means listed above, however, in a particular embodiment, the two surfaces may each comprise and/or may be formed from a common thermoplastic polymer that may facilitate a material bond or weld to the adjoining surface. Structurally, because the interface between the front and rear bond surfaces  50 ,  52  is generally parallel to the direction of insertion/extraction of the front body  12  onto the rear body  14 , the bond/coupling between surfaces more effectively resist extraction of the front body  12  via sheer engagement of the interface. Specifically, the sheer bond tends to distribute stresses more effectively across the entire bond surface, rather than inducing non-uniform stresses due to, for example, cantilevering. 
     The mechanical interface may be formed when the rear-most surface  54  of the front body  12  (i.e., the rear end of the frame  34 ) contacts a mating surface  56  of the rear body  14  that is in line with the outer wall  58  or other structure of the rear body  14 . This alignment allows impact loads to be directly transferred from the frame  34  to the rear body  14  and the transition surface  58  via direct contact between the materials, and is not as reliant on the strength of the bond or intermediate adhesive. 
     In some embodiments, the rear body  14  can further include one or more metallic weight structures to aid in positioning the club head center of gravity low and back. In the embodiment provided in  FIGS. 1, 2A, and 2B , the rear body  14  includes as a weight structure  60  that is integral to and encapsulated within the rear body  14  on the sole and back end of the club head  10 . In these embodiments, the weight structure  60  can be co-molded with the sole  22  and/or the rear body  14 . Further, in these embodiments, the weight structure  60  can comprise a cavity capable of receiving a weight (not shown) that is separately formed and subsequently attached to the weight structure. In other embodiments, not shown, the rear body  14  can include a cavity or void capable of removably receiving a weight that is separately formed and subsequently attached to the cavity. 
     In some embodiments, the weight structure  60  and/or weight can comprise a mass between 50 grams and 80 grams. Further, the weight structure  60  and/or weight can comprise a metallic material including but not limited to steel, tungsten, aluminum, titanium, bronze, brass, copper, gold, platinum, lead, silver, or zinc. Further, in these embodiments, the weight structure  60  and/or weight can comprise a specific gravity between 2.5 and 18. 
     As further illustrated in  FIG. 1 , in some embodiments, the front body  12  may further include a hosel bushing  62  that may operatively receive a portion of a golf shaft or shaft adapter. In one embodiment, the hosel bushing  62  may be formed from a metallic material, such as aluminum. Furthermore, it may be positioned within the hosel  38  and front body  12 , for example, by being adhered into place or by being over-molded, such as through an insert molding process. In some embodiments, the hosel bushing  62  or other metallic components on the club head can comprise an anodized outer layer or can comprise a galvanic corrosion barrier to prevent galvanic corrosion. 
     Polymeric Face Constructions 
       FIG. 3  schematically illustrates an embodiment of a front body  12  that comprises a molded, fiber-filled thermoplastic composite. Such a composite material comprises both a thermoplastic resin and a plurality of distributed discontinuous fibers (i.e., “chopped fibers”). The discontinuous/chopped fibers may include, for example, chopped carbon fibers or chopped glass fibers that are embedded within the resin prior to molding the front body  12 . While possible material configurations will be discussed further below, in one configuration, the polymeric material may be a “long fiber thermoplastic” where the discontinuous fibers are embedded in a thermoplastic resin and each have a designed fiber length of from about 3 mm to about 12 mm. In another configuration, the polymeric material may be a “short fiber thermoplastic” where the discontinuous fibers are similarly embedded in a thermoplastic resin, though may each have a designed length of from about 0.01 mm to about 3 mm. In either case, it should be noted that those lengths are the pre-mixed lengths, and due to breakage during the molding process, some fibers may actually be shorter than the described range in the final component. In some configurations, the discontinuous chopped fibers may be characterized by an aspect ratio (e.g., length/diameter of the fiber) of greater than about 10, or more preferably greater than about 50, and less than about 1500. Regardless of the specific type of discontinuous chopped fibers used, in certain configurations, the material may have a fiber length of from about 0.01 mm to about 12 mm and a resin content of from about 40% to about 90% by weight, or more preferably from about 55% to about 70% by weight. 
     One suitable thermoplastic resin may include a thermoplastic polyamide (e.g., PA6 or PA66), and it may be filled with chopped carbon fiber (i.e., a carbon-filled polyamide). Other resins may include certain polyimides, polyamide-imides, polyphenylene sulfides (PPS), polyetheretherketones (PEEK), polycarbonates, engineering polyurethanes, and/or other similar materials. 
     While the use of polymer composites within a club head  10  can result in an overall (structural) weight savings, their use in high stress areas of the club head  10  is complicated by their comparatively lower strength than typical metals and their highly anisotropic nature. This anisotropic nature is demonstrated by a considerably greater tensile strength of the composite when measured along an average longitudinal fiber direction than when measured perpendicular to this average fiber direction. These differences are more evident as the embedded fibers become more uniformly oriented. Depending on the design and materials chosen, certain composites may possess sufficient strength to withstand repeated ball strikes only if the embedded fibers are properly oriented. 
     One attribute of injection molded fiber-filled polymers is that fiber orientation tends to follow the flow of polymer/flow front within the mold during creation.  FIG. 4  schematically illustrates a plurality of chopped fibers  70  embedded within a polymer resin  72 , such as in a wall of the hosel  38 . As shown, each fiber  70  may have a length  76  that is from about 0.01 mm to about 12 mm (note that the illustrated fibers are not necessarily illustrated to scale in either size or density). During a molding process, such as injection molding, embedded fibers  70  tend to align with a direction of the flowing polymer. With some fibers (i.e., particularly with short fiber reinforced thermoplastics) and resins, the alignment tends to occur more completely close to the walls of the mold or edge of the part. These layers are referred to as shear layers  78  or skin layers. Conversely, within a central core layer  80 , the fibers  70  can sometimes be more randomized and/or perpendicular to the flowing polymer. In these embodiments, the thickness  82  of the core layer  80  can be altered by various molding parameters including molding speed (i.e., slower molding speed can yield a thinner core layer  80 ) and mold design. With the present design, it is desirable to minimize the thickness  82  of any randomized core layer  80  to enable better control over fiber orientation. 
     Because the strike face  30 , frame  34 , and hosel  38  are generally the highest-stress portions of the club head  10 , particular attention must be paid to the design if attempting to use filled polymer composites in the front body  12 . Poorly oriented fiber content may result in a strike face  30  that lacks sufficient structure to withstand repeated impact forces. During an impact, stresses tend to radiate outward from the impact location while propagating toward the rear of the club head  10 . Additionally, bending moments are imparted about the shaft, which induces material stresses between the impact location and the hosel  38 , and along the hosel  38 /parallel to a hosel axis  90 . Therefore, in an ideal design, it is preferable for the embedded fibers to generally follow these same directions; namely: within the hosel  38  parallel to the hosel axis  90 ; across at least the center of the face  30  (represented by the horizontal face axis  92 ); and, generally outward from the face center with the fibers turning largely rearward within the frame  34  (i.e., parallel to a fore-rear axis  94 ). 
     Because the discontinuous fibers are mixed within the flowable polymer prior to forming the part, it is impossible to guarantee perfect alignment. With that said, however, the design of the front body  12  and manner of injection molding (e.g., fill rate, gating/venting, and temperature) may be controlled to align as many of the embedded fibers with these axes as possible. For example, within the hosel, it is preferable if greater than about 50% of the fibers are aligned within 30 degrees of the hosel axis  90 . Between the center of the face and the hosel  38 , it is preferable if greater than about 50% of the fibers are aligned within 30 degrees of the horizontal face axis  92 , and within the frame  34 , it is preferable if greater than about 50% of the fibers are aligned within 30 degrees of the fore-rear axis  94 . In another embodiment, greater than about 60% of the fibers within the hosel  38  are aligned within 25 degrees of the hosel axis  90 , greater than about 60% of the fibers between the center of the face and the hosel  38  are aligned within 25 degrees of the horizontal face axis  92 , and greater than about 60% of the fibers within the frame  34  are aligned within 25 degrees of the fore-rear axis  94 . In still another embodiment, greater than about 70% of the fibers within the hosel  38  are aligned within 20 degrees of the hosel axis  90 , greater than about 70% of the fibers between the center of the face and the hosel  38  are aligned within 20 degrees of the horizontal face axis  92 , and greater than about 70% of the fibers within the frame  34  are aligned within 20 degrees of the fore-rear axis  94 . 
       FIGS. 5-6  illustrate a front body design that generally accomplishes the fiber alignment described above. The flow and fiber alignment is schematically illustrated in  FIG. 5 , and with additional clarity via the mold flow simulation outputs as can be seen in the illustrations in  FIGS. 8-9 . As shown through these figures, flowable polymer passes from a sprue  100  and connected gate  102  directly into the toe portion  26  of the front body  12 , such as illustrated in  FIG. 5 . From there, the polymer may flow across the face  30 , and then upward through the hosel  38 . By flowing across the face  30  and upward through the hosel  38 , any weld lines are pushed high and to the heel side of the hosel  38 , which is generally the lowest stress area of the hosel  38 . If the body  12  were attempted to be gated at the hosel  38 , there would more likely be a weld line in or near the face  30 , or on the toe side of the hosel  38 , which experiences comparatively greater stress than the heel side. Because weld lines have a lower ultimate strength than the typical polymer, it is important to ensure that they do not get formed in areas that typically experience higher stresses. 
     To encourage the polymer to fill the hosel  38  from bottom to top, it may be desirable to fill the face from a location near the toe  26  and that is at or preferably above the horizontal centerline  104  of the face  30  (i.e., between the crown  20  and a line drawn through the center of the face  106  and parallel to a ground plane when the club is held at address). This may encourage the flow  108  and corresponding fiber alignment to follow a generally downward slant from above the horizontal centerline  104  at the toe  26  toward the center of the face  106  while between the toe and the center  106 . Following this, at the center  106 , the flow  110  and corresponding fiber alignment may generally be parallel to the horizontal centerline  104  at or immediately surrounding the center of the face  106 . Finally, the flow  112  may arc upward and fill the hosel  38  largely from the bottom toward the neck. The general directional references illustrated at  108 ,  110 , and  112  are generally intended to indicate that greater than about 50% of the fibers within the polymer are aligned within about 30 degrees of the indicated direction, or more preferably that more than about 60% of the fibers are aligned within about 25 degrees of the indicated direction, or even more preferably that more than about 70% of the fibers are aligned within about 20 degrees of the indicated direction. 
     As shown in  FIG. 5 , in one embodiment, the gate  102  may be a fan gate that is located in a rear half of the frame  34  immediately below the crown  20 . To promote the directional flow  108 ,  110  across the face  30  while also encouraging a slight downward arc at  108 , a flow leader  114  may protrude from a rear surface  116  of the strike face  30 , such as shown in  FIGS. 6-7 . As shown, the flow leader  114  is an embossed channel that extends from an edge of the face  30  at or near the gate and propagates away from the gate, inward toward a central region of the face  30  to direct the flow of material. It may serve as a path of comparatively lower resistance for material to flow, thus ensuring a primary flow-direction. In some embodiments, the flow leader  114  may be raised above the surrounding surface  116  by a height of from about 0.5 mm to about 1.5 mm, or from about 0.7 mm to about 1.0 mm. Furthermore, the flow leader  114  may have a lateral width, measured orthogonally to the height and to a line from the origin of the flow leader at the toe  26  to the face center  106 , of from about 5 mm to about 15 mm, or from about 7 mm to about 12 mm. 
     As further shown in  FIGS. 6-7 , in one embodiment, the flow leader  114  may lead into a thickened central region  118  of the face  30 . This thickened central portion  118  may primarily be used to stiffen the central region of the face against impacts so that the face moves more as a single unit while avoiding local deformations. From a molding perspective, this thickened region  118  may serve as a well or manifold of sorts that may supply polymer radially outward to fill the frame from front to back (or at least to steer polymer flowing through the thinner areas toward the rear edge  120  of the frame). The flow convergence from the thicker region  118  to the surrounding thinner areas will also aid aligning the embedded fibers. 
     As noted above,  FIGS. 8-9  illustrate two molding simulation outputs that depict the front body  12  at different stages of fill/molding. As shown, the primary flow path originates from the upper toe portion  26  and then is directed downward (at  108 ) via the flow leader  114  to the thickened center region  118 , after which it crosses the face (at  110 ) and generally turns back upward (at  112 ) when filling the hosel  38  from bottom to top. While the primary flow is down and across the face  30 , it can also be seen that polymer turns rearward (at  122 ) from this primary flow path into the frame  34 , which is consistent with the flow convergence from the flow leader and thickened center region into the comparatively thinner periphery and frame regions. 
     In many embodiments, the face thickness may vary such that the minimum face thickness ranges from 0.114 inch and 0.179 inch, and the maximum face thickness ranges from 0.160 inch to 0.301 inch. The minimum face thicknesses can be 0.110 inches, 0.114 inches, 0.115 inches, 0.120 inches, 0.125 inches, 0.130 inches, 0.135 inches, 0.140 inches, 0.145 inches, 0.150 inches, 0.155 inches, 0.160 inches, 0.165 inches, 0.170 inches, 0.175 inches, 0.179 inches, or 0.180 inches. The maximum face thickness can be 0.160 inches, 0.165 inches, 0.170 inches, 0.175 inches, 0.180 inches, 0.185 inches, 0.190 inches, 0.195 inches, 0.200 inches, 0.205 inches, 0.210 inches, 0.215 inches, 0.220 inches, 0.225 inches, 0.230 inches, 0.235 inches, 0.240 inches, 0.245 inches, 0.250 inches, 0.255 inches, 0.260 inches, 0.265 inches, 0.270 inches, 0.275 inches, 0.280 inches, 0.285 inches, 0.290 inches, 0.300 inches, 0.301 inches, 0.305 inches, or 0.310 inches. 
       FIG. 10  schematically illustrates an embodiment of a thermoplastic composite front body  200  that includes an embedded reinforcing elements  202  that extend across at least a portion of the strike face  30 . In one configuration, the illustrated embodiment may be formed via an insert injection molding process, whereby the reinforcing elements  202  are placed within the mold prior to the flowable polymer being injected. 
     The reinforcing elements  202  may comprise a plurality of continuous fibers, wires, or other elongate elements that extend across a substantial portion of the face (i.e., more than about 25 mm, or more than about 30 mm, or more than about 35 mm, or more than about 40 mm). In some embodiments, these elements  202  may include a first plurality of elements  204  that extend generally parallel to each other in a first spaced arrangement. Furthermore, in some embodiments, the reinforcing elements  202  may include a second plurality of elements  206  that extend generally parallel to each other in a second spaced arrangement, where the first and second plurality of elements  204 ,  206  are not parallel. As shown in  FIG. 10 , in one configuration, the first and second plurality of elements  204 ,  206  may form an orthogonal mesh or grid. In some embodiments, the grid may be unitary, such that the first and second plurality of elements  204 ,  206  are integral to each other. In other embodiments, they may be woven in an alternating pattern. 
     To ensure that the reinforcing elements  202  are adequately embedded within the composite and that they do not simply create a weakened internal boundary plane, it may be necessary to ensure a minimum spacing between adjacent elements. For example, as generally illustrated in the cross-sectional view provided in  FIG. 11 , each element may generally have a diameter  208 , and adjacent elements may be spaced by a separation distance  210 . In one configuration, the minimum spacing is such that the separation distance  210  is greater than or equal to the average diameter  208  of the adjacent elements. In other embodiments, the separation distance  210  may be more than two times the average diameter  208  of the adjacent elements, or more than three times the average diameter  208  of the adjacent elements, or four times the average diameter  208  of the adjacent elements. In fact, the greater the spacing, the more completely the elements  202  will be integrated within the molded polymer. In one example, the average diameter may be from about 0.05 mm to about 1.5 mm, or from about 0.1 mm to about 1.0 mm. 
     The continuous reinforcing elements  202  may be formed from any high strength material including carbon fiber, glass fiber, aramid fiber, or the like. In some embodiments, however, the reinforcing elements  202  may be formed from metal, with each reinforcing element being a wire or plurality of bundled wires. In one configuration, the metal may be a metal that is traditionally used to form golf club faces such as, for example, a stainless steel or steel alloy (e.g., C300, C350, Ni (Nickel)-Co (Cobalt)-Cr (Chromium)-Steel Alloy, 565 Steel, AISI type 304 or AISI type 630 stainless steel), a titanium alloy (e.g., a Ti-6-4, Ti-3-8-6-4-4, Ti-10-2-3, Ti 15-3-3-3, Ti 15-5-3, Ti185, Ti 6-6-2, Ti-7s, Ti-92, or Ti-8-1-1 Titanium alloy), or other similar materials. 
     In one configuration, such as shown in  FIG. 11 , the reinforcing elements  202  may generally be aligned with and parallel to the ball striking surface  32 . Such an embodiment may serve to reinforce the polymer and polymer integrity against impacts. In another configuration, however, such as shown in  FIG. 12 , the reinforcing elements  202  may generally be aligned with and parallel to the rear surface  212  of the face  30 . Such an embodiment may provide greater resilience against bending and face deflection, which may lower the characteristic time of the face (which is measured according to USGA guidelines). In still a third configuration, such as shown in  FIG. 13 , a first plurality of reinforcing elements  214  may be parallel to the ball striking surface  32  and a second plurality of reinforcing elements  216  may be parallel to the rear surface  212 . Such an embodiment may provide a combination of the benefits described with respect to  FIGS. 11 and 12 . 
     Thermoplastic Composite Materials 
     As mentioned above, the molded front body  12  may be formed from a thermoplastic composite material that comprises a thermoplastic polymer matrix material and a filler. Exemplary thermoplastic polymer matrix materials include polycarbonate (PC), polyester (PBT), polyphenylene sulfide (PPS), polyamide (PA) (e.g. polyamide 6 (PA6), polyamide 6-6 (PA66), polyamide-12 (PA12), polyamide-612 (PA612), polyamide 11 (PA11)), thermoplastic polyurethane (TPU), polyphthalamide (PPA), acrylonitrile butadiene styrene (ABS), polybutylene terephthalate (PBT), polyvinylidene fluoride (PVDF), polyethylene (PE), polyphenylene ether/oxide (PPE), polyoxymethylene (POM), polypropylene (PP), styrene acrylonitrile (SAN), polymethylpentene (PMP), polyethylene terephthalate (PET), acrylonitrile styrene acrylate (ASA), polyetherimide (PEI), polyvinylidene fluoride (PVDF), polymethylmethacrylate (PMMA), polyether ether ketone (PEEK), polyether ketone (PEK), polyetherimide (PEI), polyethersulfone (PES), polyphenylene oxide (PPO), polystyrene (PS), polysulfone (PSU), polyvinyl chloride (PVC), liquid crystal polymer (LCP), thermoplastic elastomer (TPE), ultra-high molecular weight polyethylene (UHMWPE), or alloys of the above described thermoplastic materials, such as an alloy of acrylonitrile butadiene styrene (ABS) and polycarbonate (PC) or an alloy of acrylonitrile butadiene styrene (ABS) and polyamide (PA). 
     For example, in some embodiments, the thermoplastic composite material can include thermoplastic polyurethane (TPU) as the thermoplastic polymer matrix material. TPU comprises a chemical structure consisting of linear segmented block copolymers having hard and soft segments. In some embodiments, the hard segments comprise aromatic or aliphatic structures, and the soft segments comprise polyether or polyester chains. In other embodiments, the thermoplastic polymer matrix material comprising TPU can have a hard and soft segments with different chemical structures. 
     For further example, in some embodiments, the thermoplastic composite material can include polyamine 6-6 (PA66) or polyamide 6 (PA6) as the thermoplastic polymer matrix material.  FIG. 10  illustrates the chemical structure of polyamide 6-6 (PA6-6). PA66 is a type of polyamide made of two monomers, including hexamethylenediamine and adipic acid, each containing 6 carbon atoms.  FIG. 11  illustrates the chemical structure of polyamide 6 (PA6), a semicrystalline polyamide. 
     The fillers of the thermoplastic composite material can include fibers, beads, or other structures comprising various materials (described below) that are mixed with the thermoplastic polymer. The fillers can provide structural reinforcement, weighting, lightening, or various other characteristics to the thermoplastic composite material. In many embodiments, the fillers can comprise carbon or glass. However, in other embodiments, the fillers can comprise other suitable materials. For example, the fillers of one or more lamina layer can comprise aramid fibers (e.g. Nomex, Vectran, Kevlar, Twaron), bamboo fibers, natural fibers (e.g. cotton, hemp, flax), metal fibers (e.g. titanium, aluminum), glass beads, tungsten beads, or ceramic fibers (e.g. titanium dioxide, granite, silicon carbide). 
     The fillers or fibers can be short (less than approximately 0.5 mm in length or diameter), long (ranging in length or diameter between approximately 0.5 mm to approximately 40 mm, or more preferably between approximately 5 mm and approximately 12 mm), or continuous (greater than approximately 40 mm in length). In many embodiments, the front body  12  and the rear body  14  comprise short and/or long fibers. In other embodiments, the front body  12  and the rear body  14  can comprise continuous fibers instead of, or in addition to the short and long fibers. 
     In many embodiments, the thermoplastic composite material can comprise 30-40% fillers by volume. In other embodiments, the thermoplastic composite material can comprise up to 55%, up to 60%, up to 65%, or up to 70% fillers by volume. 
     In many embodiments, the thermoplastic composite comprises a specific gravity of approximately 1.0-2.0, which is significantly lower than the specific gravity of metallic materials used in golf (e.g. the specific gravity of titanium is approximately 4.5 and the specific gravity of aluminum is approximately 3.5). Further, in many embodiments, the thermoplastic composite material comprises a strength to weight ratio or specific strength greater than 1,000,000 PSI/(lb/in3), and a strength to modulus ratio or specific flexibility greater than 0.009. The specific gravity, specific strength, and specific flexibility of the thermoplastic composite material enable significant weight savings in the club head  10 , while maintaining durability. 
     Methods of Forming Golf Club Heads Having Thermoplastic Composite Materials 
     In the illustrated embodiment of  FIGS. 1-3 , the club head comprises (1) a front body  12  having a strike face  30  and a frame  34  that surrounds and extends rearward from the strike face  30  and a return portion, and (2) a rear body  14  comprising a crown portion  20  and a sole portion  22 . In these or other embodiments, the front body  12  and the rear body  14  can be formed separately and subsequently joined to form the club head  10 . The method of forming the club head  10  comprises the following steps, described in further detail below: (1) forming the front body  12 , (2) forming the crown portion  20  and the sole portion  22 , (3) coupling the crown portion  20  and the sole portion  22  to form the rear body  14 , (4) coupling the front body  12  and the rear body  14  via the joint  40  to form the club head  10 , wherein the crown portion  20  and the sole portion  22  and/or the front body  12  and the rear body  14  are coupled by fusion bonding. In this or other embodiments, fusion bonding can include, but is not limited to thermal welding (e.g. hot tool welding, hot gas welding, extrusion welding, infrared welding, laser welding), friction welding (e.g. spin welding, vibration welding, ultrasonic welding, stir welding) and electromagnetic welding (e.g. induction welding, dielectric welding, microwave welding, resistance welding). 
     As discussed above, the front body  12  may be formed, for example, using an injection molding process. In such a process, a flowable thermoplastic polymer is injected into a cavity of a mold, where the cavity is the negative of the part to-be-formed. Prior to injecting the flowable polymer, a plurality of discontinuous fibers are mixed into the polymer such that they are generally dispersed in a consistent manner. The flowable polymer is then injected into the mold, where it fills the cavity and solidifies. 
     In an embodiment such as shown in  FIGS. 10-13 , the reinforcing elements  202  may first be formed or otherwise provided into a substantially final form. This may happen by first providing a substantially uniform planar mesh or grid, and then either compression molding or stamping the mesh/grid into a desired final shape. Once the mesh is in a completed shape, it may then be inserted into the mold prior to injecting the flowable polymer. During the injecting process, the flowable polymer will surround the formed mesh and fill the interstitial spaces. 
     In some embodiments, the rear body  14  may be formed from one or more thermoplastic composite materials to facilitate the fusion bond with the front body  12  (i.e., via the joint  40  described above). In one configuration, the rear body  14  may be constructed from injection molded and compression molded thermoplastic composites, such as described in U.S. Pat. No. 9,925,432, which is incorporated by reference in its entirety. By incorporating a common, or otherwise miscible thermoplastic polymer in both the rear body  14  and front body  12 , the fusion joint may be made feasible and more robust. 
     Advantages of Club Heads Comprising Thermoplastic Composite Materials 
     The thermoplastic composite material enables heating and reforming (due to the thermoplastic matrix material). Accordingly, an entire hollow body club head can be molded in pieces and then fused together without the need for intermediate adhesives. This is generally contrary to many current club heads that have structural metal frames and composite panel inserts (comprising thermoset matrices, which cannot be reformed upon heating). 
     Further, the thermoplastic composite material reduces the structural mass of the club head beyond what is possible with traditional metal and composite forming techniques used in golf club heads. The structural weight savings accomplished through this design may be used to either reduce the entire weight of the club head  10  (which may provide faster club head speeds and/or longer hitting distances) or to increase the amount of discretionary mass that is available for placement on the club head (i.e., for a constant club head weight). In a preferred embodiment, the additional discretionary mass is incorporated in the final club head design via one or more metallic weights  60  that are coupled with the sole  22  and/or rear-most portion of the club head  10 . 
     The thermoplastic composite material provides the structural integrity necessary to withstand impact forces, while saving weight as described above. In many embodiments, the fiber reinforced thermoplastic composite can comprise a strength to weight ratio and a strength to modulus ratio (as described above) greater than ratios achievable with metallic materials. 
     Example 1: Face Comprising TPU Thermoplastic Composite Material 
     According to one example, a golf club head has a strike face  30  comprising a thermoplastic composite material. The thermoplastic composite material comprises TPU as a thermoplastic polymer matrix material, with 40% fill of long carbon fibers. The strike face  30  comprises a thickness of 0.265 inch, resulting in an average coefficient of restitution (COR) between 0.821 and 0.826. As a comparative, a similar strike face comprising a titanium alloy resulted in a coefficient of restitution of approximately 0.828. Accordingly, the coefficient of restitution of the exemplary strike face  30  comprising TPU with 40% fill of long carbon fibers, and having a thickness of 0.265 inch, maintained a similar coefficient of restitution (within 0.85%) compared to a similar strike face comprising a titanium alloy. Further, the exemplary strike face  30  maintained durability during testing. The results described herein were obtained by testing COR plates per USGA methods. 
     Example 2: Face Comprising TPU Thermoplastic Composite Material 
     According to another example, a golf club head has a strike face  30  comprising a thermoplastic composite material. The thermoplastic composite material comprises TPU as a thermoplastic polymer matrix material, with 50% fill of long carbon fibers. The strike face  30  comprises a thickness of 0.265 inch, resulting in an average coefficient of restitution (COR) of 0.815. As a comparative, a similar strike face comprising a titanium alloy resulted in a coefficient of restitution of approximately 0.828. Accordingly, the coefficient of restitution of the exemplary strike face  30  comprising TPU with 50% fill of long carbon fibers, and having a thickness of 0.265 inch, maintained a similar coefficient of restitution (within 1.6%) compared to a similar strike face comprising a titanium alloy. Further, the exemplary strike face  30  maintained durability during testing. The results described herein were obtained by testing COR plates per USGA methods. 
     Example 3: Face Comprising PA6 Thermoplastic Composite Material 
     According to one example, a golf club head has a strike face  30  comprising a thermoplastic composite material. The thermoplastic composite material comprises TPU as a thermoplastic polymer matrix material, with 50% fill of long carbon fibers. The strike face  30  comprises a thickness of 0.275 inch, resulting in an average coefficient of restitution (COR) of 0.814. As a comparative, a similar strike face comprising a titanium alloy resulted in a coefficient of restitution of approximately 0.828. Accordingly, the coefficient of restitution of the exemplary strike face  30  comprising TPU with 50% fill of long carbon fibers, and having a thickness of 0.275 inch, maintained a similar coefficient of restitution (within 1.7%) compared to a similar strike face comprising a titanium alloy. Further, the exemplary strike face  30  maintained durability during testing. The results described herein were obtained by testing COR plates per USGA methods. 
     Example 4: Face Comprising PA6 Thermoplastic Composite Material 
     According to one example, a golf club head has a strike face  30  comprising a thermoplastic composite material. The thermoplastic composite material comprises TPU as a thermoplastic polymer matrix material, with 40% fill of long carbon fibers. The strike face  30  comprises a thickness of 0.266 inch, resulting in an average coefficient of restitution (COR) of 0.808. As a comparative, a similar strike face comprising a titanium alloy resulted in a coefficient of restitution of approximately 0.828. Accordingly, the coefficient of restitution of the exemplary strike face  30  comprising TPU with 40% fill of long carbon fibers, and having a thickness of 0.266 inch, maintained a similar coefficient of restitution (within 2.4%) compared to a similar strike face comprising a titanium alloy. Further, the exemplary strike face  30  maintained durability during testing. The results described herein were obtained by testing COR plates per USGA methods. 
     Example 5: Face Comprising PA6 Thermoplastic Composite Material 
     According to one example, a golf club head has a strike face  30  comprising a thermoplastic composite material. The thermoplastic composite material comprises TPU as a thermoplastic polymer matrix material, with 50% fill of long carbon fibers. The strike face  30  comprises a thickness of 0.272 inch, resulting in an average coefficient of restitution (COR) of 0.802. As a comparative, a similar strike face comprising a titanium alloy resulted in a coefficient of restitution of approximately 0.828. Accordingly, the coefficient of restitution of the exemplary strike face  30  comprising TPU with 50% fill of long carbon fibers, and having a thickness of 0.272 inch, maintained a similar coefficient of restitution (within 3.1%) compared to a similar strike face comprising a titanium alloy. Further, the exemplary strike face  30  maintained durability during testing. The results described herein were obtained by testing COR plates per USGA methods. 
     Replacement of one or more claimed elements constitutes reconstruction and not repair. Additionally, benefits, other advantages, and solutions to problems have been described with regard to specific embodiments. The benefits, advantages, solutions to problems, and any element or elements that may cause any benefit, advantage, or solution to occur or become more pronounced, however, are not to be construed as critical, required, or essential features or elements of any or all of the claims. 
     As the rules to golf may change from time to time (e.g., new regulations may be adopted or old rules may be eliminated or modified by golf standard organizations and/or governing bodies such as the United States Golf Association (USGA), the Royal and Ancient Golf Club of St. Andrews (R&amp;A), etc.), golf equipment related to the apparatus, methods, and articles of manufacture described herein may be conforming or non-conforming to the rules of golf at any particular time. Accordingly, golf equipment related to the apparatus, methods, and articles of manufacture described herein may be advertised, offered for sale, and/or sold as conforming or non-conforming golf equipment. The apparatus, methods, and articles of manufacture described herein are not limited in this regard. 
     While the above examples may be described in connection with a driver-type golf club, the apparatus, methods, and articles of manufacture described herein may be applicable to other types of golf club such as a fairway wood-type golf club, a hybrid-type golf club, an iron-type golf club, a wedge-type golf club, or a putter-type golf club. Alternatively, the apparatus, methods, and articles of manufacture described herein may be applicable other type of sports equipment such as a hockey stick, a tennis racket, a fishing pole, a ski pole, etc. 
     Moreover, embodiments and limitations disclosed herein are not dedicated to the public under the doctrine of dedication if the embodiments and/or limitations: (1) are not expressly claimed in the claims; and (2) are or are potentially equivalents of express elements and/or limitations in the claims under the doctrine of equivalents. 
     Various features and advantages of the disclosure are set forth in the following clauses: 
     Clause 1: A golf club head comprising: a front body including a strike face defining a ball striking surface, a hosel, and a frame that at least partially surrounds the strikeface and extends rearward from a perimeter of the strikeface away from the ball striking surface; a rear body coupled to the front body to define a hollow cavity therebetween; and wherein: the strike face and frame are formed from a thermoplastic composite comprising a thermoplastic polymer having a plurality of discontinuous fibers embedded therein; each of the plurality of discontinuous fibers have a length of less than about 40 mm; and between a center of the strike face and the hosel, greater than about 50% of the plurality of discontinuous fibers are aligned within about 30 degrees of parallel to a horizontal axis extending from the center of the strike face to the hosel. 
     Clause 2: The golf club head of clause 1, wherein the front body comprises a rear edge that abuts the rear body when the rear body is coupled to the front body; and wherein within the frame, greater than about 50% of the plurality of discontinuous fibers are aligned within about 30 degrees of parallel to an axis extending from the ball striking surface to the rear edge and perpendicular to the horizontal axis. 
     Clause 3: The golf club head of clause 2, wherein the axis extending from the ball striking surface to the rear edge is perpendicular to the rear edge. 
     Clause 4: The golf club head of any of clauses 1-3, wherein the front body includes: a toe portion on an opposite side of the strike face from the hosel; the frame defining a portion of a crown and a sole; the horizontal axis extending between the crown and the sole and through the center of the strike face; a rear surface on an opposite side of the strike face from the ball striking surface; and wherein the strike face includes a flow leader protruding from the rear surface away from the ball striking surface, the flow leader extending from the toe portion between the crown and the horizontal axis toward the center of the strike face. 
     Clause 5: The golf club head of clause 4, further comprising a thickened center region protruding from the rear face surface away from the ball striking surface and centered about the center of the strike face. 
     Clause 6: The golf club head of any of clauses 1-5, wherein the thermoplastic composite is a polyamide and each of the plurality of discontinuous fibers are carbon fibers. 
     Clause 7: The golf club head of any of clauses 1-6, further comprising a plurality of continuous reinforcing elements embedded within the thermoplastic polymer of the strike face. 
     Clause 8: The golf club head of clause 7, wherein the plurality of continuous reinforcing elements comprise an orthogonal mesh. 
     Clause 9: The golf club head of any of clauses 7-8, wherein the plurality of reinforcing elements comprise metallic wires. 
     Clause 10: The golf club head of any of clauses 7-9, wherein each of the plurality of reinforcing elements have a diameter and at least a first subset of the plurality of reinforcing elements are arranged in a parallel arrangement; wherein adjacent reinforcing elements of the first subset of the plurality of reinforcing elements are spaced apart from each other by a minimum distance; and wherein the minimum distance is at least two times an average diameter of the first subset of reinforcing elements. 
     Clause 11: A polymeric front body of a golf club head comprising: a strike face defining a ball striking surface, the strike face having a geometric center and defining a horizontal axis extending through the geometric center; a frame that at least partially surrounds the strikeface and extends rearward from a perimeter of the strikeface away from the ball striking surface, the frame defining a crown portion and a sole portion; a hosel, wherein the horizontal axis extends between the geometric center and the hosel and between the crown and at least a portion of the sole; a fan gate extending from the frame between the horizontal axis and the crown. 
     Clause 12: The polymeric front body of clause 11, wherein the strike face further defines a rear surface opposite the ball striking surface, the front body further comprising: a flow leader protruding from the rear surface away from the ball striking surface, the flow leader extending from a portion of the strike face nearest to the fan gate toward the center of the strike face. 
     Clause 13: The polymeric front body of clause 12, further comprising a thickened center region protruding from the rear face surface away from the ball striking surface and centered about the geometric center of the strike face. 
     Clause 14: The polymeric front body of any of clauses 11-13, wherein the strike face and frame comprise a thermoplastic composite comprising a thermoplastic polymer having a plurality of discontinuous fibers embedded therein, each of the plurality of discontinuous fibers have a length of less than about 40 mm. 
     Clause 15: The polymeric front body of clause 14, wherein between the center of the strike face and the hosel, greater than about 50% of the plurality of discontinuous fibers are aligned within about 30 degrees of parallel to the horizontal axis. 
     Clause 16: The polymeric front body of any of clauses 14-15, wherein the frame defines a rear edge opposite the strike face, and wherein within the frame, greater than about 50% of the plurality of discontinuous fibers are aligned within about 30 degrees of parallel to an axis extending from the ball striking surface to the rear edge and perpendicular to the horizontal axis. 
     Clause 17: The polymeric front body of clause 16, wherein the axis extending from the ball striking surface to the rear edge is perpendicular to the rear edge. 
     Clause 18: The polymeric front body of any of clauses 11-17, further comprising a plurality of reinforcing elements embedded within the strike face. 
     Clause 19: The polymeric front body of clause 18, wherein the plurality of reinforcing elements comprise an orthogonal mesh. 
     Clause 20: The polymeric front body of any of clauses 18-19, wherein each of the plurality of reinforcing elements have a diameter and at least a first subset of the plurality of reinforcing elements are arranged in a parallel arrangement; wherein adjacent reinforcing elements of the first subset of the plurality of reinforcing elements are spaced apart from each other by a minimum distance; and wherein the minimum distance is at least two times an average diameter of the first subset of reinforcing elements. 
     Clause 21: The polymeric front body of any of clauses 18-20, wherein the plurality of reinforcing elements comprise metallic wires.