CN117460562A

CN117460562A - Composite material swatter and method of forming same

Info

Publication number: CN117460562A
Application number: CN202280041415.6A
Authority: CN
Inventors: 休斯·戴维斯; 格里塔·戴维斯; 罗克福德·麦克因斯
Original assignee: Lovolin Sports Co ltd
Current assignee: Lovolin Sports Co ltd
Priority date: 2021-04-09
Filing date: 2022-04-08
Publication date: 2024-01-26
Also published as: US20240189679A1; WO2022217045A1; EP4319893A1

Abstract

The present teachings contemplate a beat comprising a striking portion defining a central axis, a handle portion, and a tapered portion contiguous with both the handle portion and the striking portion, a sandwich structure comprising a core layer and a first skin bonded to the core layer, the first skin comprising a first fabric layer and a second fabric layer bonded to the first fabric layer.

Description

Composite material swatter and method of forming same

Technical Field

The present teachings relate generally to composites and structures for forming sporting equipment and, more particularly, to fibrous composites for forming picobeats.

Background

Most of the picocell racquets and other racquets currently on the market are composed of carbon or glass fibers. While the properties of these materials are desirable, these materials are neither sustainable nor recyclable and involve significant carbon emissions. However, efforts to avoid the use of these materials have typically resulted in performance defects in beats. Simply replacing carbon or glass fibers with natural and sustainable materials results in beats not functioning properly and/or being uncomfortable to use.

The international union of picoballs (IFP) and the united states picoball association (USAPA) have established rules and regulations for picoballs. Criteria for an allowable picocell include limitations on surface roughness, reflection, size and appearance.

It is therefore desirable to develop a beat that utilizes natural and sustainable materials in unique construction and manufacturing techniques so that carbon and glass fibers can be eliminated or minimized while still allowing the beat to perform well and provide great comfort to the user. There is also a need for a racquet that utilizes natural and sustainable materials while still meeting the requirements set forth by the international pinkeye association (IFP) and the united states pinkeye association (USAPA).

Disclosure of Invention

The teachings herein relate to a racquet comprising a striking portion defining a central axis; a handle portion and a tapered portion contiguous with both the handle portion and the striking portion; a sandwich structure comprising a core layer and a first skin bonded to the core layer, the first skin comprising a first fabric layer and a second fabric layer bonded to the first fabric layer.

The beat may include a substrate interposed between the core layer and the first skin, the substrate configured to promote bonding of the core layer to the first skin. The core layer may be a honeycomb structure comprising one or more cells. The substrate may be a nonwoven polymeric fabric configured to prevent resin from penetrating into one or more cells of the honeycomb.

The first fabric layer may be a hemp fabric between 100gsm and 170 gsm. The first fabric layer may include a weave pattern positioned between-10 degrees and 10 degrees relative to the central axis. The second fabric layer may be a twill scrim between 200gsm and 300 gsm. The second fabric layer may include a weave pattern between-10 degrees and 10 degrees relative to the central axis. The first fabric layer may be a bi-directional woven fabric. The second fabric layer may be a bi-woven fabric positioned between-5 degrees and 5 degrees relative to the first fabric layer.

The core may comprise a synthetic material. The core may comprise a natural material. The core may comprise impregnated fibrous material. The core may comprise prepreg laminates. One or more of the first skin and the second skin may include at least six different layers stacked in a spiral pattern. The core may comprise a touch-dry material. The core may comprise an adhesive material. The core may comprise at least two different geometries. The core may include a first central geometry surrounded by a second peripheral geometry different from the first central geometry. The core may include a first central geometry that is generally honeycomb-shaped. The core may include a first central geometry surrounded by a second peripheral geometry, and the second peripheral geometry is generally helical.

Additive manufacturing processes may form the core. The handle portion may comprise a material forming a second perimeter geometry. The core may comprise a spiral shape. The core may comprise a spiral shape and the thickness of the material used to form the spiral shape increases as the spiral progresses to the outer edge of the beat. The thickness of the material used to form the spiral increases from about 20% to about 40% from the start of the spiral to the end of the spiral. The core may include a plurality of branches formed according to merry's law. The core may comprise a cardboard grid comprising an optional resin coating. The core may comprise a woven composite material. The woven composite material may be impregnated with a resin.

The first skin may be cured separately from the core layer and may be bonded to the core layer after the curing process. The first skin may be cured with the core layer such that the first skin and the core layer are bonded via a curing process. The first skin and the second skin may be formed of the same material. The first skin and the second skin may be formed of different materials.

The nonwoven substrate may be located between the first skin and the core layer. The nonwoven substrate may be located between the second skin and the core layer. The nonwoven substrate may comprise a polymeric material. The nonwoven substrate may comprise a polypropylene or polyester material. The nonwoven substrate may be bonded to the core layer by a hot melt adhesive, an adhesive film, an adhesive resin, or some combination thereof.

The first fabric layer, the second fabric layer, or both may be a fabric impregnated with a resin selected from the group consisting of epoxy resins, polyester resins, vinyl ester resins, phenolic resins, biological resins, thermoplastic resins, or any combination thereof. The first fabric layer, the second fabric layer, or both may be formed of fibers pre-impregnated with resin. The first fabric layer, the second fabric layer, or both may include a fibrous mat, cloth, or some combination thereof. The first fabric layer, the second fabric layer, or both may comprise a density of at least about 120g/cm ² But less than about 150g/cm ² Is a plain weave hemp. The first fabric layer, the second fabric layer, or both may comprise unidirectional braids. The first fabric layer, the second fabric layer, or both may include a bi-directional braid having wires extending in a first x-direction and wires extending in a first y-direction. The first fabric layer, the second fabric layer, or both comprise a +45/-45 degree weave, wherein the first x-direction is substantially perpendicular to the first y-direction. The first fabric layer, the second fabric layer, or both may comprise a 90/0 degree weave.

The teachings herein also relate to a beat comprising a first composite skin comprising: a first fabric layer having a bidirectional braid and formed of flax fibers, and a second fabric layer having a bidirectional braid and formed of hemp fibers; a second composite skin, the second composite skin comprising: a third fabric layer having a bidirectional braid and formed of flax fibers, and a fourth fabric layer having a bidirectional braid and formed of hemp fibers; and a honeycomb core structure interposed between the first composite skin and the second composite skin.

The first fabric layer may be outwardly facing such that the second fabric layer is interposed between the first fabric layer and the honeycomb core structure. The third fabric layer may be outwardly facing such that the fourth fabric layer is interposed between the third fabric layer and the core structure.

The flapper may include a striking portion and a handle portion defining a central axis such that the striking portion and the handle are symmetrical about the central axis, the striking portion including a front edge positioned opposite the handle portion and perpendicular to the central axis.

The first fabric layer may be positioned such that at least one of the first x-direction and the first y-direction is positioned within 10 degrees of parallel to the central axis. The third fabric layer may be positioned such that at least one of the third x-direction and the y-direction is positioned within 10 degrees of parallel to the central axis. The second fabric layer may be positioned such that at least one of the second x-direction and the second y-direction is positioned within 10 degrees of parallel to the central axis. The fourth fabric layer may be positioned such that at least one of the fourth x-direction and the fourth y-direction is positioned within 10 degrees of parallel to the central axis.

The flapper may include an edge guard positioned around the periphery of the striking portion. The beat may comprise a second edge, the second edge being positioned parallel to the central axis. The beat may comprise a third edge, which is positioned parallel to the central axis.

The first, second, third and fourth fabric layers may all be prepreg sheets. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof is a fabric impregnated with a resin selected from the group consisting of epoxy resins, polyester resins, vinyl ester resins, phenolic resins, biological resins, thermoplastic resins, or any combination thereof. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof is composed of fibers pre-impregnated with resinAnd (5) forming. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof may include a fibrous mat, a cloth, or some combination thereof. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof may comprise a density of at least about 120g/cm ² But less than about 150g/cm ² Is a plain weave hemp. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof may comprise a unidirectional braid. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof may include a bi-directional knit having threads extending in a first x-direction and threads extending in a first y-direction. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof may comprise a +45/-45 degree weave, wherein the first x-direction is substantially perpendicular to the first y-direction. The first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof may comprise a 90/0 degree weave.

The teachings herein also contemplate a composite structure for forming a beat, comprising: at least two layers of about 200gsm of a twill woven natural fiber fabric, a resin impregnated in the fabric, and a honeycomb core adhered to the at least two layers via the resin.

The teachings herein also relate to a composite structure for forming a beat, comprising: at least one first layer of a biaxial natural fiber fabric having a fiber orientation of +45° and-45 ° or +/-30 ° or +/-60 °, at least one second layer of a unidirectional natural fiber fabric having a fiber orientation of 0 ° or 90 °, and a resinous material in direct contact with one or both of the first layer or the second layer.

The teachings herein also relate to a forming method for forming a laminate of beats, including laying up at least three layers of braided hemp mixed with a resin content of about 30% to about 50% by weight, and compressing the three layers using a compression molding machine to form the laminate.

The teachings herein also contemplate a composite structure for forming a beat, comprising at least one layer of woven natural fiber fabric having fiber orientations of 0 ° and 90 ° and a thermoplastic resin selected from polypropylene, polylactic acid, or a combination thereof impregnated in the at least one layer of woven natural fiber fabric.

The composite structure may include a core, which may be a honeycomb core located adjacent to the first layer, adjacent to the second layer, or both.

The teachings herein also relate to a sandwich panel comprising a first composite skin comprising: a first fabric layer having flax fibers, the first fabric layer having an areal weight of between 200 grams per square meter and 300 grams per square meter, inclusive, and a second fabric layer having hemp fibers, the second fabric having an areal weight of between 100 grams per square meter and 200 grams per square meter, inclusive; a second composite skin, the second composite skin comprising: a third fabric layer having flax fibers, the third fabric layer having an areal weight of between 200 grams per square meter and 300 grams per square meter, inclusive, and a fourth fabric layer having hemp fibers, the fourth fabric having an areal weight of between 100 grams per square meter and 200 grams per square meter, inclusive. The sandwich panel may include a core structure interposed between and bonded to the first and second composite skins.

The first fabric layer may include a bi-directional weave having a first warp yarn and a first weft yarn. The second fabric layer may include a bi-directional weave having a second warp yarn and a second weft yarn. The first fabric layer may be bonded to the second fabric layer such that one of the first warp threads and the first weft threads is within five degrees of parallel to the second warp threads.

The first composite skin may be bonded to the first side of the panel such that the second fabric layer is interposed between the first fabric layer and the honeycomb panel. The second composite skin may be bonded to a second side of the core structure such that the fourth fabric layer is interposed between the third fabric layer and the honeycomb core structure, the second side of the core structure being opposite the first side of the core structure.

The paddle may include a striking portion and a handle portion defining a central axis such that the striking portion and the handle are symmetrical about the central axis. The first fabric layer may be formed of a bi-directional weave and include a first warp yarn and a first weft yarn. The third fabric layer may be formed of a bi-directional weave and include a third warp yarn and a third weft yarn. The first fabric layer may be positioned such that at least one of the first warp yarn and the first weft yarn is positioned within 10 degrees of parallel to the central axis. The third fabric layer may be positioned such that at least one of the third warp yarns and the third weft yarns are positioned within 10 degrees of parallel to the central axis.

The first fabric layer may be formed of unidirectional weave and include first threads. The third fabric layer may be formed of unidirectional weave and include third strands. The first fabric layer may be positioned such that the first line is positioned within five degrees of parallel to the central axis. The third fabric layer may be positioned such that the third line is positioned within five degrees of parallel to the central axis.

The second fabric layer may be positioned such that at least one of the second x-direction and the second y-direction is positioned within 10 degrees of parallel to the central axis. The fourth fabric layer may be positioned such that at least one of the fourth x-direction and the fourth y-direction is positioned within 10 degrees of parallel to the central axis.

The first, second, third and fourth fabric layers may all be prepreg sheets.

The first fabric layer may be a synthetic fiber material and the second fabric layer may be a natural fiber material. The synthetic material may be recycled carbon fiber, recycled glass fiber, basalt, recycled ultra high molecular weight polyethylene (UHMwPE), or some combination thereof. The natural fibrous material may be selected from flax or hemp or a combination thereof. The swatter may comprise a third fabric layer, wherein the first fabric layer may be synthetic fibers, the second fiber layer may be natural fibers, and the third fiber layer may be synthetic fibers. The synthetic material may be selected from carbon fiber, basalt, or a combination thereof, and the natural fiber may be selected from flax, hemp, or a combination thereof. Vibration may be reduced during use of the swatter as compared to a swatter without a natural fiber layer.

The core layer may include a plurality of walls for forming cavities having different shapes, sizes, and cross-sections. The core layer may include a plurality of cavities having different shapes, sizes, and cross-sections such that the walls and cavities mimic the structure of a bird bone. The core layer may include a cavity that receives a plurality of equally sized generally circular members for supporting the cavity.

The teachings herein describe advantageous materials and methods associated with manufacturing beats, and more particularly materials and material arrangements and systems for forming beat cores.

Drawings

Fig. 1 is a perspective view of an exemplary embodiment of a beat according to the teachings herein.

Fig. 2 is a front view of the swatter of fig. 1.

Fig. 3 is a bottom cross-sectional view of the swatter along line AA of fig. 2.

Fig. 4 is a detailed cross-sectional view of the front of an exemplary embodiment of a beat according to the present teachings.

Fig. 5 is a detailed cross-sectional view of the front of an exemplary embodiment of a beat according to the present teachings.

Fig. 6 is a detailed cross-sectional view of the front of an exemplary embodiment of a beat according to the present teachings.

Fig. 7 is a detailed exploded view of the beat along line AA of fig. 2.

Fig. 8 is a front view of an exemplary embodiment of a beat according to the present teachings.

Fig. 9 is a detailed cross-sectional view of the front portion of the racquet of fig. 8.

Fig. 10 is a schematic view of an exemplary layered laminate according to the present teachings.

FIG. 11 shows the layered laminate of FIG. 10 during formation of a prepreg using the laminate.

Fig. 12 is a perspective view of two beats of cores of different geometry side by side with an exemplary beat of cores comprising two different geometries.

Fig. 13A to 13D illustrate the formation of an exemplary beat with a spiral core.

Fig. 14A to 14D show variations of an exemplary beat core having a "tree" form.

FIG. 15 illustrates an exemplary beat-core structure mimicking a "bone-like" arrangement.

FIG. 16 is a cross-sectional view of an exemplary sandwich panel core arrangement.

Fig. 17 is a perspective view of an exemplary mesh core for a beat.

Fig. 18 is a cross-sectional view of an exemplary woven material for the beat core.

Fig. 19 is a cross-sectional view of an exemplary woven material for the beat core.

FIG. 20 is an exemplary recovery flow chart using recovered beat core material.

Detailed Description

The present teachings address one or more of the above needs by the improved composite structures and methods described herein. The illustrations and descriptions set forth herein are intended to familiarize those skilled in the art with the present teachings, their principles, and their practical applications. Those skilled in the art may modify and apply the present teachings in its numerous forms, as may be best suited to the requirements of a particular use. Thus, the particular embodiments of the present teachings set forth are not intended to be exhaustive or limiting of the present teachings. The scope of the present teachings should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. Other combinations are also possible as will be gathered from the following claims, which are also incorporated by reference into this written description.

The present application relates to and claims the benefit of the filing date of U.S. provisional application serial No. 63/172,752, filed on 4/9 at 2021, the contents of which are incorporated herein by reference for all purposes.

A picoball racket (e.g., badminton racket, tennis racket, table tennis racket, etc.) includes a striking portion formed of a sandwich panel having a core structure interposed between two composite laminate layers. The core structure may be formed of lightweight materials such as foam, polymer cores, aluminum honeycomb, and polymer honeycomb. The core structure of the picoball racquet must be sufficiently rigid so that the picoball racquet meets the requirements of the international picoball association (IFP) and the united states picoball association (USAPA).

The teachings herein relate to materials and methods for forming beats. The beats described herein may include a core layer and one or more composite skins. The composite skin may be formed from a variety of different natural, synthetic and recycled materials, and may preferably be formed from a combination of these materials. The composite skin may be formed using multiple layers (e.g., two, three, four, eight, or even more layers). The layers may comprise the same material. The layers may comprise different materials. The layers may be selected to alternate between two or more materials. Each layer may itself comprise more than one type of material (e.g., more than one type of fiber, or a fiber having a coating thereon). The layers may be coated with resin, impregnated with resin, or each fiber of a layer may be coated with resin. These layers may be formed of woven or non-woven materials. These layers may be formed of fibers having relatively low glass transition temperatures. The fibers and/or resins may be formed from thermoplastic materials that may be repaired, reformed, and/or recycled upon exposure to heat. The resin and/or fibers may be formed from a thermoset or thermosettable material. The resin and/or fiber may comprise a foam material or a material adapted to foam upon exposure to a stimulus.

The tempo may utilize resins, adhesives, films, tapes or other similar attachment means to form the final combination of core and composite skin. The processes described herein for forming a swatter may include one or more heating, curing, pressing, or compressing steps. The composite skin may be formed and cured in a separate step and may then be assembled with the core layer, which assembly process may also include a curing step. Curing may occur at ambient temperature. Curing may occur upon exposure to heat, UV light, microwaves, induction heat or other stimuli.

The forming method may include forming a first composite skin and a second composite skin by layering one or more layers onto a platen press to form an uncured first composite skin component and a second composite skin component. The first composite skin, the core structure, and the second composite skin may be layered to form an uncured sandwich panel assembly. In some embodiments, the first composite skin, the core structure, and the second composite skin are layered such that the first composite skin and the second composite skin are each in direct planar contact with the core structure (core layer). The first fabric layer and the second fabric layer may form a first composite skin. The fourth fabric layer and the third fabric layer may form a second composite skin.

The uncured composite skin (including the first composite skin and the second composite skin) may be encapsulated within a vacuum bag. The uncured composite skin may be compacted within a vacuum bag. The uncured and compacted composite skin may then be placed in an autoclave (autoclaving) while the uncured composite skin remains within the vacuum bag. The uncured composite skin is cured in an autoclave and then assembled with the core and heated in a platen press.

The beats described herein may be treated and/or shaped to form a desired texture (e.g., roughness) on the outer surface of the beat. The texture of the bat is important to spin the ball and allow graphics and/or paint to adhere to the surface of the bat. The roughness tolerance limit specified by USAPA should be no greater than 30 micrometers (μm) at Rz readings (average maximum height, peak valley) and no greater than 40 micrometers (μm) at Rt readings (maximum height, peak valley). As one non-limiting example, a lightly woven textured peel ply or release film (typically having a weight of 20gsm to 90gsm, or even 25gsm to 55 gsm) is placed on the a side (e.g., the outside) of the composite skin and cured with the skin. The release layer may then be removed, leaving a light texture specified by IFP/USAPA of slightly less than or equal to 30Rz and 40 Rt.

A custom cut/designed flat surface may also be utilized to create a mold with an average texture reading of 30Rz and 40Rt that exactly meets IFP/USAPA specifications using fine CNC milling or laser. The surface will have a sharp, high friction texture, such as a triangular wave, rather than a rolling texture, such as a sinusoidal wave. The skin may be cured on the flat mold and, when removed from the mold, the texture is imparted to the outer ("a") surface of the skin.

It is also possible that heated textured rolls may be used to impart texture to the skin surface after it has cured, wherein the texture on the roll is similar to the flat surface set forth above and presses a specific surface texture into the mold. The surface may have a sharp texture, such as a triangular wave, rather than a rolling texture, such as a sinusoidal wave. This sharp texture allows for more friction between the ball and the striking surface than a rounded sinusoidal wave structure.

Referring now to fig. 1, a perspective view of a racquet 100 (e.g., a picoball racquet, a racquet (tennis, badminton, etc.) according to one exemplary embodiment is shown. The racquet 100 includes a sandwich panel 102 (e.g., a racquet core), edge guards 104, grip strips 106, and end caps 108. The mezzanine panel 102 is formed in the shape of a racquet 100 and includes a striking portion 110, a handle portion 112, and a tapered portion 114, the tapered portion 114 extending between and adjoining the striking portion 110 and the handle portion 112. In some embodiments, the mezzanine panel 102 is formed in a non-beat shape and then cut to have the shape shown in fig. 1. The sandwich panel 102 (fig. 3) is formed from a core structure 118 interposed between a first composite skin 120 and a second composite skin 122. The composite skins 120, 122 are bonded (e.g., bonded, adhered, cured, etc.) to the core structure 118, such as by an adhesive or resin via an autoclaving process. In some embodiments, the core structure 118 is cured with the composite skins 120, 122. In some embodiments, the composite skins 120, 122 are formed separately from the core structure 118 and then bonded to the core structure 118, for example with an adhesive or resin.

Mezzanine panel 102 provides improved feel to the user of racquet 100 without sacrificing rigidity, while still meeting the IFP set criteria. The sandwich panel 102 also provides improved aesthetics to the racquet 100 when compared to other racquet that are currently available for sale. The natural aesthetics provided by flax, twills, hemp and similar materials are often desirable to users of picocell racquets. Also, the use of organic materials in panels that meet the requirements of IFP and USAPA is unique to the industry.

Referring now to FIG. 2, a front view of the racquet 100 is shown. The beat 100 is defined by a central axis 125 extending along a longitudinal dimension of the beat 100 and through the handle portion 112. In some embodiments, the beat 100 is symmetrical about the central axis 125. The beat 100 also includes a first edge 128 (e.g., a front edge) extending along a first end 130 of the mezzanine panel 102. The first end 130 is positioned opposite the second end 132 of the striking portion 110. The first edge 128 is bisected (e.g., substantially bisected) by the central axis 125 and extends perpendicular (e.g., substantially perpendicular) to the central axis 125.

The beat 100 also includes a second edge 134 and a third edge 136, the third edge 136 being opposite the second edge 134. Both the second edge 134 and the third edge 136 extend parallel to the central axis 125 and perpendicular to the first edge 128. The first edge 128 abuts both the second edge 134 and the third edge 136. In some embodiments, the first edge 128 and the second edge 134 intersect at a first rounded corner 138. In some embodiments, the first edge 128 and the third edge 136 intersect at a second rounded corner 140. The first rounded corner 138 and the second rounded corner 140 are opposite the handle portion 112.

Referring now to FIG. 3, a cross-section of the beat 100 along line AA of FIG. 2 is shown. The sandwich panel 102 is formed from a core structure 118 interposed between two composite skins, shown as a first composite skin 120 and a second composite skin 122. In some embodiments, the first and second composite skins 120, 122 are substantially similar (e.g., exhibit similar material properties such as stiffness and tensile strength). In some embodiments, the first composite skin 120 and the second composite skin 122 are different and exhibit different material properties.

The first and second composite skins 120, 122 are bonded to the core structure 118 such that the core structure 118 is interposed between the first and second composite skins 120, 122. In some embodiments, the first composite skin 120 is cured separately from the core structure 118 and bonded to the core structure 118 after the first composite skin 120 is cured. In some embodiments, the first composite skin 120 is cured with the core structure 118 such that the first composite skin 120 and the core structure 118 are cured together.

To improve the adhesion of the first and second composite skins 120, 122 to the core structure 118, a substrate 124 may be positioned between the composite skins 120, 122 and the core structure 118. In some embodiments, the substrate 124 is a nonwoven fabric, such as a nonwoven fabric formed from polypropylene, polyester, and similar polymeric materials. The substrate 124 may be directly bonded (e.g., cured) to the core structure 118, such as by heat-fusing, an adhesive film, or a resin.

The core structure 118 may be formed from paper, synthetic paper, metal, composite materials, polymeric materials, and the like. In some embodiments, the core structure 118 includes a plurality of cells that extend through (e.g., perforate) the core structure 118. For example, the core structure 118 may be a honeycomb core. In some embodiments, for example when the core structure 118 is a honeycomb core, the core structure 118 may include a base 124 extending over the core structure 118 to prevent resin from penetrating into the cells of the core structure 118.

The first composite skin 120 is a laminate structure and includes a plurality of fabric layers cured with a resin. In other words, the first composite skin 120 includes a fiber-reinforced resin layer (e.g., matrix resin in a cured and consolidated composite form). The first composite skin 120 may include any number of fabric layers layered in various orientations relative to one another. Each fabric layer is formed from a material (e.g., flax, hemp, kevlar, carbon, wood, etc.), directionality (e.g., bi-axial, bi-directional, tri-axial, uni-directional, etc.), weave (e.g., twill, plain, satin, etc.), and density (in grams/cubic centimeter (g/cm) ³ ) Measurement). As used herein, when two fabrics are "in line" or "aligned," then at least one of the warp and/or weft of the first fabric is substantially parallel to at least one of the warp and/or weft of the second fabric. This applies to uniaxial, biaxial and triaxial braiding. This also applies to increasingly unique weaves, e.g. 0 Weaving/60 (e.g., 0/120 weaving).

The first composite skin 120 includes a first fabric layer 142 and a second fabric layer 144 bonded (e.g., cured) to the first fabric layer 142. The first fabric layer 142 may be a biaxial fabric. In some embodiments, first fabric layer 142 comprises a twill weave. In some embodiments, the first fabric layer 142 is formed of an organic material, such as flax or hemp. In some embodiments, the first fabric layer 142 is a layer having a density of about 132 grams per square centimeter (g/cm) ² ) Is a plain weave hemp.

In some embodiments, the first fabric layer 142 includes a bi-directional braid having wires extending in a first x-direction 170 and having wires extending in a first y-direction 172. In some embodiments, the first fabric layer 142 comprises a +45/-45 degree weave, wherein the first x-direction is perpendicular (e.g., substantially perpendicular) to the first y-direction. In some embodiments, the first fabric layer 142 comprises a 90/0 degree weave. In some embodiments, first fabric layer 142 is a twill weave fabric. The twill weave may be a plain weave, a 2 x 2 weave, or the like. In some embodiments, the first fabric layer 142 is formed of an organic material, such as hemp, flax, wood, and the like. As used herein, "organic material" refers to a material that is associated with or derived from an organism. The organic material does not include carbon fiber, glass fiber, aramid, and the like. In some embodiments, the first fabric layer 142 includes flax fibers in a twill weave pattern. In some embodiments, the first fabric layer 142 is formed from twill-woven hemp fibers. The first fabric layer 142 may have a density between 200 grams per square meter (gsm) and 300 grams per square meter. In some embodiments, the first fabric layer 142 has a density between 225gsm and 275 gsm. In some embodiments, the first fabric layer 142 has a density between 240gsm and 260 gsm.

The second fabric layer 144 includes a bi-directional weave having threads extending in a second x-direction 174 and threads extending in a second y-direction 176. In some embodiments, the second fabric layer 144 comprises a 2 x 2 twill weave. In some embodiments, the second fabric layer 144 is formed of an organic material, such as flaxOr hemp. In some embodiments, the second fabric layer is a layer having a density of about 245g/cm ² Is a 2 x 2 twill woven linen fabric. In some embodiments, the warp and weft (wire thickness, etc.) have similar (e.g., identical except for manufacturing tolerances) thicknesses.

Referring now to fig. 5, the first fabric layer 142 is positioned at an angle α relative to the second fabric layer 144. In some embodiments, the first x-direction 170 is aligned with at least one of the second x-direction 174 and the second y-direction 176. In other words, the angle α is zero and the first fabric layer 142 is aligned with the second fabric layer 144 (fig. 5). In some embodiments, as shown in fig. 6, the first fabric layer 142 is positioned within +/-10 degrees of rotation of the alignment of the second fabric layer 144. In other words, the first x-direction 170 is positioned within 10 degrees of rotation of at least one of the second x-direction 174 and the second y-direction 176. In some embodiments, the first fabric layer 142 is positioned at 45 degrees of rotation relative to the second fabric layer 144 (fig. 7). In other words, the first x-direction 170 is positioned at approximately 45 degrees of rotation of both the second x-direction 174 and the second y-direction 176. In some embodiments, the first fabric layer 142 is positioned between 55 degrees of rotation and 35 degrees of rotation of the second fabric layer 144.

When the first composite skin 120 is bonded to the core structure 118, the first fabric layer 142 is interposed between the second composite skin 122 and the core structure 118 such that the second composite skin 122 faces outwardly. In some embodiments, the second fabric layer 144 is positioned such that the second fabric layer 144 is aligned with the central axis 125, as shown in fig. 2. In other words, when the first composite skin 120 is bonded to the core structure 118, the second fabric layer 142 is positioned such that at least one of the second x-direction 174 and the second y-direction is substantially parallel to the central axis 125. In some embodiments, the second fabric layer 144 is positioned between-10 degrees of rotation to 10 degrees of rotation of the central axis 125 when the first composite skin 120 is bonded to the core structure 118. In some embodiments, the second fabric layer 144 is positioned at an angle of rotation of about 45 ° relative to the central axis 125.

Referring now to fig. 7, an exploded view of the mezzanine panel 102 is shown. In some embodiments, the first fabric layer 142 and the second fabric layer 144 are "dry" fabrics impregnated with resins (e.g., epoxy resins, polyester resins, vinyl ester resins, phenolic resins, biological resins, thermoplastic resins (polypropylene, PLA, polycarbonate, etc.). In some embodiments, at least one or both of the first fabric layer 142 and the second fabric layer 144 are prepreg sheets. As used herein, the term "prepreg" refers to fibers pre-impregnated with a resin, such as a combination of a fibrous substrate (e.g., mat, fiber, or cloth material) and a resin impregnated on and into the substrate.

Located between the first composite skin 120 and the substrate 124 may be a first adhesive film 180. The first adhesive film 180 may be supported by a scrim. Interposed between the first fabric layer 142 and the second fabric layer 144 is a second adhesive film 182. The second adhesive film 182 may include a scrim. Located on the second fabric layer 144 opposite the second adhesive film 182 is a third adhesive film 184. The third adhesive film 184 is unsupported (e.g., does not include a scrim). The third adhesive film 184 faces outwardly when the sandwich panel 102 is cured. In the curing process, a release layer 186, such as ground glass or ground aluminum, may be used to provide texture 190 to the striking surface of the sandwich panel 102. Texture 190 may meet the requirements of IFP and USAPA. Specifically, the average RT texture readings taken in 6 directions may be less than or equal to 40 microns, and the average RZ texture readings taken in 6 directions may be less than or equal to 30 microns.

Referring now to fig. 8, a beat 200 according to another exemplary embodiment is shown. Beat 200 is similar to beat 100. Thus, like numbers are used to denote like parts between the racquet 100 and the racquet 200. The difference between the beat 100 and the beat 200 is that the beat 200 includes a fabric layer having a unidirectional braid.

The beat 200 comprises a first composite skin 120, the first composite skin 120 comprising a second fabric layer 244, the second fabric layer 244 comprising a unidirectional weave and being formed from flax fibers. When the first composite skin 120 is bonded to the core structure 118, the second fabric layer 244 is aligned with the central axis 125. The unidirectional fibers of second fabric layer 244 may be flax fibers that provide a desired woody or natural appearance to the user of beat 200. In some embodiments, the resin is pre-applied prior to assemblyThe second fabric layer 244 is impregnated. For example, the second fabric layer 244 may be formed fromP-UD 3.2 is provided. In some embodiments, the second fabric layer 244 has a density between 50gsm and 150 gsm. In some embodiments, the second fabric layer 244 has a density between 75gsm and 125 gsm. In some embodiments, the second fabric layer 244 has a density between 100gsm and 120 gsm.

Referring now to FIG. 9, a cross-sectional view of a racquet 200 is shown. The second fabric layer 244 is aligned with the first fabric layer 142.

Various core materials, core geometries and core forms are shown as examples in fig. 10-19. Fig. 10 shows a layered spiral laminate structure 302 comprising a plurality of layers 300a-300 s. These layers may be stacked and impregnated with resin to form a prepreg 304 such as shown in fig. 11.

As an additional example, fig. 12 shows a first beat design 306 using a core 308 formed of an additively manufactured spiral filler 310. The second core 312 is shown having a honeycomb configuration 314. By combining the first design 306 and the second design 312, the third core configuration 316 is shown as including a honeycomb inner core 318 and a spiral outer core 320.

The core may be formed to have a particular shape found in nature ("biomimetics"). As one example, fig. 13A-13D illustrate a core 322 formed as a spiral 324, the spiral 324 having a resulting spider web shape 326. In this or other configurations, the material portions used to form the core may be thicker than the other material portions. In this particular spiral example, the cross-section of the interior of spiral 328 at its widest point may be thinner than the cross-section of the portion of spiral 330 located along the outermost portion of the beat. In one embodiment, the thickness of the material increases in a gradual manner as the material moves from the interior of helix 328 to the exterior of helix 330. The increase may be at least about 20%, at least about 30%, at least about 40%, or even at least about 50% when comparing the inner 328 and outer 330 portions.

As another example of bionics, fig. 14A to 14D show a device with There are variations of the exemplary beat-core in the form of a "tree". Each core includes one or more main branch portions 332. Extending from each main branch portion 332 are one or more second branch portions 334. In fig. 14A and 14D, the third branch portion 336 is shown extending from the second branch portion 334. At each point where the second branch portion 334 or the third branch portion 336 extends from the main branch portion 332 or the second branch portion 334, respectively, the branch portions may be separated according to a unique ratio. The ratio may be according to merry's law. The ratio of branches may be such that the major branch portion has a cubic (or square) radius equal to the second branch portion's cubic (or square) radius plus the third branch portion's cubic (or square) radius (r 1 ³ ＝r2 ³ +r3 ³ Or r1 ² ＝r2 ² +r3 ² ). The use of such ratios may be optimal for providing lightweight support for the handle/user and for conducting energy and vibrations to the handle/user for optimal responsiveness, feel and/or performance. Vibrations along the branches can also be reduced.

As discussed herein, the beat core may comprise a sandwich panel arrangement. A specific exemplary sandwich panel arrangement is shown in fig. 15 and 16. Fig. 15 shows a sandwich panel structure 338, 342 that simulates a "bone-like" arrangement of a tortuous wall structure with bends to form cavities 340, 344 of different sizes and shapes. Fig. 16 illustrates various sandwich panel configurations 346, each sandwich panel configuration 346 including a core 348, the core 348 including a plurality of cavities 350 along the length of the core 348.

It is also desirable to use recycled material to form the beat core. Fig. 17 shows a recycled cardboard grid arrangement for core 352. The grid is in a stacked form wherein a first grid of paperboard having a plurality of first parallel ribs 354 is stacked onto a second grid of paperboard having a plurality of second parallel ribs 356, the second parallel ribs 356 being disposed perpendicular to the first parallel ribs 354. The paperboard (which is a porous material) may also be impregnated with a resin 358, the resin 358 being adapted to adhere the mesh portion to one or more facesheets (not shown).

Materials used to form the beat core may include woven and non-woven composite structures. These structures may be formed of a material that is particularly suitable for coating and/or impregnating with a resin material, which may be a thermoplastic or thermosetting resin and may have adhesive and/or foaming properties. Fig. 18 illustrates an exemplary braided core material 360 including a plurality of identical hexagonal cavities 362 formed by a plurality of wall structures 364. The wall structure 364 may include a material 366 that is porous and capable of absorbing resin. Fig. 19 shows a similar woven material 368 for forming a beat core. Each sample 368 has a different thickness than the other samples, and each sample includes top and bottom walls 372 and a cavity 370 formed between the top and bottom walls 372.

The present teachings describe the use of a variety of materials to form the beats described herein, and many of these materials are suitable for recycling or other forms of reuse. The entire swatter described herein may be suitable for recycling, or alternatively, certain portions of the swatter may be suitable for recycling. As one non-limiting example, fig. 20 shows a recovery flow chart using recovered beat core material. As shown, the beat 374 is adapted to be ground into a pellet 376. The pellets may be treated to have a desired appearance (dyeing, bleaching, coating, spraying, etc.). The pellets may be molded into pellets 378 (which may be picoballs). The resulting balls are then further recovered by grinding into pellets 380 and combining with beat pellets 376 to form more balls 378.

As used herein with respect to a range of values, the terms "about," "approximately," and similar terms generally mean +/-10% of the disclosed value, unless otherwise specified. As used herein with respect to structural features (e.g., to describe shape, size, orientation, direction, relative position, etc.), the terms "about," "approximately," and similar terms are intended to encompass minor variations in structure that may result from, for example, a manufacturing or assembly process, and are intended to have a broad meaning consistent with the usual and acceptable usage by those of ordinary skill in the art to which the subject matter of this disclosure pertains. Accordingly, these terms should be construed to indicate that insubstantial or inconsequential modifications or alterations to the described and claimed subject matter are considered to be within the scope of the disclosure as recited in the appended claims.

It should be noted that the term "exemplary" and variations thereof as used herein to describe various embodiments are intended to indicate that such embodiments are possible examples, representations, or illustrations of possible embodiments (and such term is not intended to imply that such embodiments are necessarily particular or best examples).

As used herein, the term "joined" and variations thereof refer to two members being joined directly or indirectly to one another. Such engagement may be fixed (e.g., permanent or fixed) or movable (e.g., removable or releasable). Such joining may be achieved by two members being directly joined to each other, by two members being joined to each other using a separate intermediate member and any additional intermediate member being joined to each other, or by two members being joined to each other using an intermediate member, which is integrally formed as a single unitary body with one of the two members. If "coupled" or variations thereof is modified by additional terminology (e.g., directly coupled), the general definition of "coupled" provided above is modified by the plain meaning of the additional terminology (e.g., "directly coupled" meaning that two members are joined without any separate intermediate members), resulting in a narrower definition than the general definition of "coupled" provided above. Such a combination may be mechanical, electrical or fluid.

The locations of elements referred to herein (e.g., "top," "bottom," "above," "below") are used merely to describe the orientation of the various elements in the drawings. It should be noted that the orientation of the various elements may be different according to other exemplary embodiments, and such variations are intended to be covered by this disclosure.

Although the figures and descriptions may illustrate a particular order for method steps, the order for such steps may differ from what is depicted and described unless otherwise specified above. Also, two or more steps may be performed concurrently or with partial concurrence unless indicated otherwise above.

It is important to note that any element disclosed in one embodiment may be combined with or utilized with any other embodiment disclosed herein. While only one example of an element from one embodiment that can be combined or utilized in another embodiment is described above, it should be understood that other elements of the various embodiments can be combined or utilized with any of the other embodiments disclosed herein.

As used herein, the present teachings contemplate that any member of a genus (list) may be excluded from the genus, unless otherwise specified; and/or any member of the markush group may be excluded from the group.

Unless otherwise indicated, any numerical values recited herein include all values which increment in one unit from a lower value to a higher value, provided that there is a spacing of at least 2 units between any lower value and any higher value. As an example, if a value of an amount, property, or process variable (e.g., temperature, pressure, time, etc.) of a component is stated to be, for example, 1 to 90, preferably 20 to 80, more preferably 30 to 70, it is intended that mid-range values (e.g., 15 to 85, 22 to 68, 43 to 51, 30 to 32, etc.) are within the teachings of the present specification. Likewise, individual intermediate values are within the scope of the present teachings. For values less than one, one unit is considered to be 0.0001, 0.001, 0.01 or 0.1 as appropriate. These are only examples of what is specifically intended, and all possible combinations of numerical values between the lowest value and the highest value enumerated are to be considered to be expressly stated in this application in a similar manner. It can be seen that the teachings herein of amounts expressed in "parts by weight" also contemplate the same ranges expressed in weight percent. Thus, the first and second substrates are bonded together, the expression within the scope of the "x" parts by weight of the resulting polymer blend composition "also contemplates" the same listed ranges of amounts of the resulting polymer blend composition by weight of 'x'.

Unless otherwise indicated, all ranges include both endpoints and all numbers between the endpoints. The use of "about" or "approximately" in connection with a range applies to both ends of the range. Accordingly, "about 20 to 30" is intended to cover "about 20 to about 30," including at least the specified endpoints.

The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The term "consisting essentially of" as used to describe a combination shall include the identified element, ingredient, component or step as well as such other element, ingredient, component or step that does not materially affect the basic and novel characteristics of the combination. The use of the terms "comprises" or "comprising" to describe combinations of elements, components, parts or steps herein also encompasses embodiments consisting of or consisting essentially of the elements, components, parts or steps.

Multiple elements, components, parts or steps may be provided by a single integrated element, component, part or step. Alternatively, a single integrated element, component, means or step may be divided into separate plural elements, components, means or steps. The disclosure of "a" or "an" describing an element, component, or step is not intended to exclude additional elements, components or steps.

It is to be understood that the above description is intended to be illustrative, and not restrictive. Many embodiments and many applications other than the examples provided will be apparent to those of skill in the art upon reading the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. The disclosures of all articles and references, including patent applications and publications, are incorporated by reference for all purposes. The omission of any aspect of the subject matter disclosed herein in the appended claims is not an disclaimer of that subject matter nor should the inventors regard that subject matter as part of the disclosed subject matter.

Claims

1. A racket, comprising:

a striking portion defining a central axis; a handle portion and a tapered portion contiguous with both the handle portion and the striking portion;

a sandwich structure, the sandwich structure comprising:

a core layer; and

a first skin bonded to the core layer, the first skin comprising:

a first fabric layer; and

a second fabric layer bonded to the first fabric layer.

2. The beat of claim 1, further comprising a substrate interposed between the core and the first skin, the substrate configured to facilitate bonding of the core to the first skin.

3. The beat of claim 2, wherein:

the core layer is a honeycomb structure comprising one or more cells; and is also provided with

The substrate is a non-woven polymeric fabric configured to prevent resin from penetrating into the one or more cells of the honeycomb.

4. The swatter of any one of the preceding claims wherein said first fabric layer is a hemp fabric between 100gsm and 170 gsm.

5. The swatter of any one of the preceding claims wherein said first fabric layer comprises a weave pattern positioned between-10 degrees and 10 degrees relative to said central axis.

6. The swatter of any one of the preceding claims wherein said second fabric layer is a twill scrim between 200gsm and 300 gsm.

7. The swatter of any of the preceding claims wherein said second fabric layer comprises a weave pattern between-10 degrees and 10 degrees relative to said central axis.

8. The beat of any one of the preceding claims, wherein:

the first fabric layer is a bidirectional woven fabric;

the second fabric layer is a bi-directional knit fabric between-5 degrees and 5 degrees relative to the first fabric layer.

9. A swatter according to any preceding claim wherein the core comprises a synthetic material.

10. The swatter of any one of the preceding claims wherein said core comprises a natural material.

11. The beat of any of the preceding claims, wherein the core comprises an impregnated fibrous material.

12. The swatter of any one of the preceding claims wherein said core comprises a prepreg laminate.

13. The beat of any of the preceding claims, wherein one or more of the first and second skins comprises at least 6 different layers stacked in a spiral pattern.

14. The swatter of any of the preceding claims wherein said core comprises a touch-dry material.

15. The swatter of any of the preceding claims wherein said core comprises a viscous material.

16. The beat of any of the preceding claims, wherein the core comprises at least two different geometries.

17. The beat of any of the preceding claims, wherein the core comprises a first central geometry surrounded by a second peripheral geometry different from the first central geometry.

18. The beat of any of the preceding claims, wherein the core comprises a first central geometry that is generally honeycomb shaped.

19. The beat of any of the preceding claims, wherein the core comprises a first central geometry surrounded by a second peripheral geometry, and the second peripheral geometry is substantially helical.

20. The beat of any of the preceding claims, wherein an additive manufacturing process forms the core.

21. The racket of claim 19, wherein the handle portion includes a material that forms the second peripheral geometry.

22. The beat of any of the preceding claims, wherein the core comprises a spiral shape.

23. A swatter according to any preceding claim wherein said core comprises a spiral shape and the thickness of material used to form said spiral shape increases as the spiral progresses to the outer edge of the swatter.

24. The beat of claim 23, wherein the thickness of the material used to form the spiral increases from about 20% to about 40% from the start of the spiral to the end of the spiral.

25. The beat of any of the preceding claims, wherein the core comprises a material according to merry's law (r 1 ² ＝r2 ² +r3 ² ) A plurality of branches formed.

26. A beat according to any of the preceding claims, wherein the core comprises a cardboard grid comprising an optional resin coating.

27. The beat of any of the preceding claims, wherein the core comprises a braided composite material.

28. The swatter of claim 27 wherein said braided composite material is impregnated with a resin.

29. The swatter of any one of the preceding claims wherein the first skin is cured separately from the core and bonded to the core after the curing process.

30. The beat of any of the preceding claims, wherein the first skin and the core layer are cured together such that the first skin and the core layer are bonded via a curing process.

31. The swatter of any one of the preceding claims wherein said first and second skins are formed of the same material.

32. The swatter of any one of the preceding claims wherein said first and second skins are formed of different materials.

33. The beat of any of the preceding claims, wherein a non-woven substrate is located between the first skin and the core layer.

34. The beat of any of the preceding claims, wherein a nonwoven substrate is located between the second skin and the core layer.

35. The swatter of claim 33 or claim 34 wherein said nonwoven substrate comprises a polymeric material.

36. The swatter of claim 33 or claim 34 wherein said nonwoven substrate comprises a polypropylene or polyester material.

37. The beat of any of claims 33 to 36, wherein the nonwoven substrate is bonded to the core layer by a hot melt adhesive, an adhesive film, an adhesive resin, or some combination thereof.

38. The swatter of any one of the preceding claims wherein said first fabric layer, said second fabric layer or both are fabrics impregnated with a resin selected from the group consisting of epoxy resins, polyester resins, vinyl ester resins, phenolic resins, bio-resins, thermoplastic resins or any combination thereof.

39. The swatter of any one of the preceding claims wherein said first fabric layer, said second fabric layer or both are formed from fibres pre-impregnated with resin.

40. The beat of any of the preceding claims, wherein the first fabric layer, the second fabric layer, or both comprise a fibrous mat, a cloth, or some combination thereof.

41. The beat of any of the preceding claims, wherein the first fabric layer, the second fabric layer, or both comprise a density of at least about 120g/cm ² But less than about 150g/cm ² Is a plain weave hemp.

42. The beat of any of the preceding claims, wherein the first fabric layer, the second fabric layer, or both comprise unidirectional braids.

43. The beat of any of the preceding claims, wherein the first fabric layer, the second fabric layer, or both comprise a bi-directional knit having threads extending in a first x-direction and threads extending in a first y-direction.

44. The beat of any of the preceding claims, wherein the first fabric layer, the second fabric layer, or both comprise a +45/-45 degree weave, wherein the first x-direction is substantially perpendicular to the first y-direction.

45. The beat of any of the preceding claims, wherein the first fabric layer, the second fabric layer, or both comprise a 90/0 degree weave.

46. A racket, comprising:

a first composite skin, the first composite skin comprising:

a first fabric layer having a bi-directional weave and formed of linen fibers;

a second fabric layer having a bi-directional weave and formed of hemp fibers;

a second composite skin, the second composite skin comprising:

a third fabric layer having a bi-directional weave and formed of linen fibers;

a fourth fabric layer having a bidirectional braid and formed of hemp fibers; and

a honeycomb core structure interposed between the first composite skin and the second composite skin.

47. The swatter of claim 46 wherein:

the first fabric layer faces outwardly such that the second fabric layer is interposed between the first fabric layer and the honeycomb core structure; and is also provided with

The third fabric layer faces outwardly such that the fourth fabric layer is interposed between the third fabric layer and the core structure.

48. The beat of claim 46 or claim 47, comprising a striking portion and a handle portion defining a central axis such that the striking portion and the handle portion are symmetrical about the central axis, the striking portion comprising a front edge positioned opposite the handle portion and perpendicular to the central axis, wherein:

the first fabric layer is positioned such that at least one of a first x-direction and a first y-direction is positioned within 10 degrees of parallel to the central axis; and is also provided with

The third fabric layer is positioned such that at least one of a third x-direction and a y-direction is positioned within 10 degrees of parallel to the central axis.

49. A swatter according to any of claims 46 to 48 wherein:

the second fabric layer is positioned such that at least one of a second x-direction and a second y-direction is positioned within 10 degrees of parallel to the central axis; and is also provided with

The fourth fabric layer is positioned such that at least one of a fourth x-direction and a fourth y-direction is positioned within 10 degrees of parallel to the central axis.

50. A swatter according to any of claims 46 to 49 comprising:

An edge guard positioned around a perimeter of the striking portion;

a second edge positioned parallel to the central axis; and

and a third edge positioned parallel to the central axis.

51. The swatter of any one of claims 46-50 wherein said first, second, third and fourth fabric layers are prepreg sheets.

52. The beat of any of claims 46 to 51, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof is a fabric impregnated with a resin selected from the group consisting of epoxy resins, polyester resins, vinyl ester resins, phenolic resins, biological resins, thermoplastic resins, or any combination thereof.

53. The beat of any of claims 46 to 52, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof, is formed from fibers pre-impregnated with a resin.

54. The beat of any of claims 46 to 53, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof comprises a fibrous pad, a cloth, or some combination thereof.

55. The beat of any of claims 46 to 54, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof comprises a density of at least about 120g/cm ² But less than about 150g/cm ² Is a plain weave hemp.

56. The beat of any of claims 46 to 55, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof comprises a unidirectional braid.

57. The beat of any of claims 46 to 56, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof comprises a bi-directional knit having threads extending in a first x direction and threads extending in a first y direction.

58. The beat of any of claims 46 to 57, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof comprises a +45/-45 degree weave, wherein a first x-direction is substantially perpendicular to a first y-direction.

59. The beat of any of claims 46 to 58, wherein the first fabric layer, the second fabric layer, the third fabric layer, the fourth fabric layer, or any combination thereof comprises a 90/0 degree weave.

60. A composite structure for forming a beat, comprising:

at least two layers of about 200gsm of twill woven natural fiber fabric;

a resin impregnated in the fabric;

a honeycomb core adhered to the at least two layers via the resin.

61. A composite structure for forming a beat, comprising:

at least one first layer of a biaxial natural fiber fabric having a fiber orientation of +45° and-45 ° or +/-30 ° or +/-60 °;

at least one second layer of unidirectional natural fiber fabric having a fiber orientation of 0 ° or 90 °; and

a resin material in direct contact with one or both of the first layer or the second layer.

62. A method of forming a laminate for forming a beat, comprising:

paving at least three layers of braided hemp mixed with a resin content of about 30% to about 50% by weight; and

the three layers are compressed using a compression molding machine to form a laminate.

63. A composite structure for forming a beat, comprising:

at least one layer of woven natural fiber fabric having fiber orientations of 0 ° and 90 °;

a thermoplastic resin impregnated in the at least one layer of woven natural fiber fabric, the thermoplastic resin selected from polypropylene, polylactic acid, or a combination thereof.

64. The composite structure of claim 61, comprising a honeycomb core positioned adjacent to the first layer, adjacent to the second layer, or both.

65. The composite structure of claim 63 comprising a honeycomb core positioned adjacent to at least one layer of said natural fiber fabric.

66. A sandwich panel comprising:

a first composite skin, the first composite skin comprising:

a first fabric layer having flax fibers, the first fabric layer having an areal weight of between 200 grams per square meter and 300 grams per square meter, inclusive;

a second fabric layer having hemp fibers, the second fabric layer having an areal weight of between 100 grams per square meter and 200 grams per square meter, inclusive;

a second composite skin, the second composite skin comprising:

a third fabric layer having flax fibers, the third fabric layer having an areal weight of between 200 grams per square meter and 300 grams per square meter, inclusive;

a fourth fabric layer having hemp fibers, the fourth fabric having an areal weight of between 100 grams per square meter and 200 grams per square meter, inclusive; and

A core structure interposed between and bonded to the first and second composite skins.

67. The sandwich panel of claim 66, wherein:

the first fabric layer comprises a bi-directional weave having a first warp and a first weft;

the second fabric layer comprises a bi-directional weave having a second warp yarn and a second weft yarn;

wherein the first fabric layer is bonded to the second fabric layer such that one of the first warp threads and the first weft threads is within five degrees of parallel to the second warp threads.

68. The sandwich panel of claim 66, wherein:

the first composite skin is bonded to a first side of the panel such that the second fabric layer is interposed between the first fabric layer and the honeycomb panel; and is also provided with

The second composite skin is bonded to a second side of the core structure such that the fourth fabric layer is interposed between a third fabric layer and a honeycomb core structure, the second side of the core structure being opposite the first side of the core structure.

69. A sandwich panel according to claim 68 comprising a striking portion and a handle portion defining a central axis such that the striking portion and the handle are symmetrical about the central axis, wherein:

The first fabric layer is formed by bi-directional weaving and includes a first warp and a first weft;

the third fabric layer is formed by bi-directional weaving and includes a third warp yarn and a third weft yarn;

the first fabric layer is positioned such that at least one of the first warp yarn and the first weft yarn is positioned within 10 degrees of parallel to the central axis; and is also provided with

The third fabric layer is positioned such that at least one of the third warp yarns and the third weft yarns are positioned within 10 degrees of parallel to the central axis.

70. A sandwich panel according to claim 68 comprising a striking portion and a handle portion defining a central axis such that the striking portion and the handle are symmetrical about the central axis, wherein:

the first fabric layer is formed of unidirectional weave and includes a first thread;

the third fabric layer is formed by unidirectional weave and includes third threads;

the first fabric layer is positioned such that the first line is positioned within five degrees of parallel to the central axis; and is also provided with

The third fabric layer is positioned such that the third line is positioned within five degrees of parallel to the central axis.

71. The picocell as defined in claim 47, wherein:

72. The picocell as defined in claim 46, further comprising:

an edge guard positioned around a perimeter of the striking portion;

a second edge positioned parallel to the central axis; and

and a third edge positioned parallel to the central axis.

73. A picocell as claimed in claim 46 or 72, wherein the first, second, third and fourth fabric layers are prepreg sheets.

74. The swatter of any one of claims 1-45 wherein said first fabric layer is a synthetic fiber material and said second fabric layer is a natural fiber material.

75. The beat of claim 74, wherein the synthetic material is recycled carbon fibers, recycled glass fibers, basalt, recycled Ultra High Molecular Weight Polyethylene (UHMWPE), or some combination thereof.

76. The beat of claim 74 or claim 75, wherein the natural fiber material is selected from flax or hemp or a combination thereof.

77. The beat of any of claims 1 to 45, comprising a third fabric layer, wherein the first fabric layer is a synthetic fiber, the second fiber layer is a natural fiber, and the third fiber layer is a synthetic fiber.

78. The swatter of claim 77 wherein said synthetic material is selected from carbon fibers, basalt, or combinations thereof, and said natural fibers are selected from flax, hemp, or combinations thereof.

79. The swatter of claim 77 or 78 wherein vibration is reduced during use of the swatter as compared to a swatter without a layer of natural fibers.

80. The beat of any of claims 1 to 45, wherein the core layer comprises a plurality of walls for forming cavities of different shapes, sizes and cross sections.

81. The beat of any of claims 1 to 45, wherein the core layer comprises a plurality of cavities having different shapes, sizes and cross sections, such that the walls and cavities mimic the structure of a bird bone.

82. The beat of any of claims 1 to 45, wherein the core layer comprises a cavity that receives a plurality of equally sized substantially circular members for supporting the cavity.