Artificial badminton

Abstract

The embodiment of the utility model provides an artificial shuttlecock which comprises a shuttlecock skirt and a shuttlecock head, the shuttlecock skirt comprises a plurality of artificial feathers and at least two supporting coils, each artificial feather comprises a feather stem and a feather leaf, each feather stem comprises a feather root part, a feather trunk part and a feather branch part, and each feather leaf comprises an inner feather leaf part, an outer feather leaf part and a bonding layer; the inner feather leaf and the outer feather leaf are bonded together through a bonding layer, and the feather trunk part and the feather branch part are wrapped by the inner feather leaf and the outer feather leaf; the feather root part is arranged in the ball head; the feather stem is made of one-way continuous special fiber reinforced plastic, the tensile and bending strength of the feather stem is higher than 0.8 Gpa, the tensile and bending modulus of the feather stem is higher than 15 Gpa, the thickness of the cross section of the feather root part and the thickness of the cross section of the feather stem part are larger than 0.65 mm, the bending resistance coefficient of the cross section is larger than 0.09 mm < 3 >, and the feather leaf is made of a foaming plastic sheet with low density, high strength and high rigidity. The artificial shuttlecock provided by the embodiment of the utility model has flight performance and appearance which are very close to those of a shuttlecock made of natural feathers, and has better hitting resistance.

Description

Technical Field

[0001] The present application relates to the technical field of sports equipment, and particularly relates to an artificial badminton. Background Art

[0002] The structural shape of the badminton used in modern badminton sports is uniformly specified by the Badminton World Federation (BWF). It consists of an elastic ball head, 15 or 16 feathers cut into a specific shape and inserted into the back of the ball head at a certain deflection angle at the root, and a trumpet-shaped skirt formed by two sets of support coils. The quality of a badminton can be measured by three categories of performance indicators: the first is the flight performance, the second is the durability, that is, the service life, and the third is the appearance.

[0003] All along, most of the feathers used in this sport's badminton are made from a dozen or so knife-shaped feathers on the wings of domestic geese and ducks, which have stable and unique flight performance. However, making badminton with natural goose and duck feathers has the following constraints: First, the consistency is poor, the collection is difficult, and the production process of the ball is complex, resulting in a high production cost; second, the supply of natural goose and duck feathers is limited and unstable. The production of geese and ducks is itself restricted by market demand and affected by factors such as plagues and environmental protection; third, the durability of the badminton is poor. After a game, one or even multiple badminton balls will be damaged. Therefore, with the popularization of badminton sports and the substantial increase in demand, the price of badminton has skyrocketed, affecting and restricting the further popularization of this sport.

[0004] Thus, people came up with the idea of using artificial materials to make badminton balls. One type is a badminton ball with a plastic skirt formed by integral injection molding. Although its durability has been improved significantly, its flight performance is far from that of a badminton ball made of goose or duck feathers. Another type is to use artificial feathers to replace natural goose or duck feathers to make the skirt of the badminton ball. However, this seemingly simple material substitution has encountered many unimaginable difficulties. On the one hand, due to the long-term practice, training, and competitions based on specific natural goose and duck feather balls, badminton enthusiasts have formed specific muscle memories and subconscious reflexes in the brain, cultivating a very delicate hitting experience. They can perceive the speed of the oncoming ball and exert hitting force to control the landing accuracy of the ball to the extent of a few centimeters. Briefly estimating, if the flying distance of the ball is 10 meters, the landing error should not exceed 10 cm, and the accuracy requirement is 1%! Thus, it can be seen that under various hitting conditions, the difference between artificial badminton balls and high-quality natural badminton balls should be precisely controlled within 1%. On the other hand, there are too many factors affecting the flight performance of badminton balls, such as weight, the axial and circumferential positions of the center of gravity, the feather stalks, the strength, stiffness, and resilience of the support coils and the feather vanes, the surface shape of the feather vanes, the deflection angle, and the wind resistance coefficient. Moreover, these factors restrict each other and are difficult to balance. The most difficult part is how to use such lightweight materials as natural feathers to achieve the same stiffness and elasticity as natural feathers and have higher strength, impact resistance, tear resistance, and fatigue resistance.

[0005] In existing artificial badminton balls, the skirt is heavy, and the center of gravity shifts towards the feather vane end. When the badminton ball is hit and turns around, the resistance moment of the skirt decreases, resulting in a large and long-lasting yaw amplitude of the badminton ball, and even tumbling, especially affecting the stability of net shots and the flight trajectory of long-distance high balls. The closer to the top of the badminton skirt, the greater the impact of overweight, because the lever arm at this position is the longest and the generated moment is the largest. The feather stalks are soft and the feather vanes are soft, lacking sufficient rigidity and resilience. When the badminton ball is hit by the racket, the reaction force of the skirt is small, and the force acting on the whole ball mainly comes from the ball head. The force application points on the racket strings are concentrated, and the action time is short. The player will feel that the ball is heavy and the impact is large, and the strings are also easily broken, just like hitting a plastic badminton ball with a very soft skirt. Secondly, the skirt is soft. Under the action of high-speed wind resistance, it shrinks inward, resulting in a decrease in resistance, a fast flight speed, and a slow attenuation of the ball speed. Moreover, after being hit, the feather vanes deform greatly and do not have the feather filament structure of natural feathers, and cannot quickly return to their original positions after deformation to restore the normal deflection angle sorting, that is, the so-called "reverse feather" state, affecting the subsequent stable flight. The service life is short, and the bending strength, shear strength, tear strength, impact strength, and corresponding fatigue strength of the feather stalks and feather vanes are poor. Summary of the Invention

[0006] To solve the above problems, this patent application provides an artificial badminton ball that has a similar appearance to natural badminton balls, with a light and rigid skirt, good flight performance, and a long service life.

[0007] The present application provides an artificial badminton, comprising:

[0008] a skirt and a ball head, wherein the skirt comprises a plurality of artificial feathers and at least two support coils, the artificial feathers comprise feather stems and feather blades, the feather stems comprise feather roots, feather shafts and feather branches, and the feather blades comprise inner feather blades, outer feather blades and an intermediate bonding layer;

[0009] the inner feather blade and the outer feather blade are bonded together through the intermediate bonding layer and wrap the feather shaft and the feather branch; the feather root is arranged in the ball head, and the support coil fixes the feather shaft;

[0010] the feather stem is made of unidirectional continuous fiber reinforced composite plastic, the longitudinal tensile and bending strength of the feather stem is higher than 0.8 GPa, the longitudinal tensile and bending modulus is higher than 15 GPa, the cross-sectional thickness of the feather root and the feather shaft is greater than 0.65 mm, and the cross-sectional bending coefficient is greater than 0.09 mm 3 ;

[0011] the feather blade is made of a foamed plastic sheet with low density, high strength and high stiffness.

[0012] In some embodiments, the thickness of the feather branch decreases in the direction towards the top of the feather blade.

[0013] In some embodiments, the cross-section of the feather stem is square or rectangular, and the cross-sectional bending coefficient at the longitudinal middle position of the feather branch is 0.5-0.7 times that of the cross-sectional bending coefficient at the bottom of the feather branch.

[0014] In some embodiments, the sum of the weights of the head of the feather blade and the feather branch is between 40-75 mg; the center of gravity of the artificial badminton is at a position 3-7 mm away from the ball head on the axis of the skirt.

[0015] In some embodiments, the unidirectional continuous fiber reinforced composite plastic is directly compounded or modified and compounded from one or more high-strength and high-modulus special continuous fibers and resin materials, and the special continuous fibers include carbon fibers, glass fibers, aramid fibers, and ultra-high molecular weight polyethylene fibers.

[0016] In some embodiments, the modified compounding means adding materials that can reduce density or increase toughness, including hollow glass microspheres, foamed plastic microspheres, and / or physical or chemical foaming agents and toughening agents, to the resin base material before or during compounding.

[0017] In some embodiments, the feather stem is made of unidirectional continuous fiber reinforced plastic formed by pultrusion or laminated compounding of one or several of high-strength and high-modulus special fibers and resin.

[0018] In some embodiments, the outer vane and the inner vane are respectively selected from the same or two different kinds of polyethylene EPE, polypropylene EPP, and polystyrene EPS foam films with foaming or micro-foaming.

[0019] In some embodiments, the intermediate adhesive layer is a single-layer or double-layer elastic hot-melt adhesive film or hot-melt adhesive non-woven fabric film with a thickness of 5-25 μm.

[0020] In some embodiments, on the back of the ball head, there are circumferentially evenly distributed inclined holes equal in number to the artificial feathers on the ball skirt. Glue is injected into the inclined holes, or after applying glue to the root of the artificial feather, it is inserted into the inclined hole for fixation, and then glue is applied at the intersection of the root of the feather and the back plane of the ball head for reinforcement.

[0021] In some embodiments, the vane parts of adjacent artificial feathers on the ball skirt overlap each other. At the middle position of the inner vane part, near the feather shaft and along the direction of the feather shaft, there is a continuous or discontinuous cutting line with a total length of 5 mm - 20 mm.

[0022] The artificial badminton of the embodiments of the present application has basically the same quality, quality distribution, stiffness, and elasticity as natural high-quality goose and duck feathers, as well as the same flight performance, and has higher bending strength and resistance to impact, shear, tear, and fatigue, has excellent durability, and can also be mass-produced at a moderate cost.

[0023] It should be understood that the content described in the utility model content part is not intended to limit the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Combined with the drawings and referring to the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present application will become more obvious. The drawings are used to better understand the solution and do not constitute a limitation to the present application. In the drawings, the same or similar reference numerals represent the same or similar elements, where:

[0025] Figure 1 Shows a schematic diagram of the overall structure of an artificial badminton according to an embodiment of the present application;

[0026] Figure 2 Shows a front view of the artificial feather of an artificial badminton according to an embodiment of the present application;

[0027] Figure 3 Shows a side split view of the artificial feather according to an embodiment of the present application;

[0028] Figure 4 Shows a schematic structural diagram of a quill according to an embodiment of the present application;

[0029] Figure 5 Shows a schematic cross-sectional structure diagram of the ball head of an artificial badminton according to an embodiment of the present application;

[0030] Figure 6 Shows a schematic structural diagram of the ball head of an artificial badminton according to an embodiment of the present application as viewed from the direction of the skirt. Detailed implementation manners

[0031] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative efforts shall fall within the scope of protection of the present application.

[0032] In addition, the term "and / or" in this article is merely a description of the associated relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0033] The technical solutions of the present application will be described below with reference to specific embodiments.

[0034] The artificial badminton of the embodiments of the present application is obtained through innovative material selection, structural design, and production processes to have substantially the same quality, quality distribution, stiffness, and elasticity as natural high-quality goose and duck feathers, so as to obtain the same flight performance, and to have higher bending strength and resistance to impact, shear, tear, and fatigue, thereby obtaining excellent durability, and can also be mass-produced at an appropriate cost.

[0035] Specifically, as Figure 1 shown, is a schematic overall structure diagram of the artificial badminton of the embodiments of the present application. In the figure, A is the axis line of the badminton, and G is the center of gravity position of the badminton. Figure 2 Shows a front view of the artificial feather of the artificial badminton according to an embodiment of the present application; Figure 3 Shows a side split view of the artificial feather according to an embodiment of the present application; Figure 4 Shows a schematic structural diagram of the quill according to an embodiment of the present application. In the figure, W is the width of the cross-section of the quill, that is, the dimension of the cross-section in the plane of the vane, and T is the thickness of the cross-section, that is, the dimension perpendicular to the width direction.Figure 5 The cross-sectional structural schematic diagram of the ball head of an artificial badminton according to an embodiment of the present application is shown; Figure 6 The structural schematic diagram of the ball head of an artificial badminton according to an embodiment of the present application as viewed from the skirt end is shown. In the figure, C is the deflection angle between the vanelets of adjacent feathers.

[0036] The artificial badminton 2 of this embodiment includes: a skirt 3 and a ball head 4. Among them, the skirt 3 includes a plurality of artificial feathers 1 and at least two support coils 5. The artificial feather 1 includes a quill 6 and a vane 7. The quill 6 includes a root part 6c, a shaft part 6b, and a branch part 6a. The vane 7 includes an inner vane 7b, an outer vane 7a, and an adhesive layer 7c. A continuous or discontinuous cutting line 7d is further provided on one side of the vane 7.

[0037] The length of the quill 6 is 73 - 78 mm, and it is divided into a root part 6c fixedly connected to the ball head, a shaft part 6b fixedly connected to the support coil, and a branch part 6a fixedly connected to the head of the vane 7. The lengths of each part are 11 - 15 mm, 20 - 25 mm, and 35 - 40 mm respectively.

[0038] The inner vane 7b and the outer vane 7a are bonded together through the adhesive layer 7c and cover the shaft part 6b and the branch part 6a; the support coil 5 fixes the shaft part 6b, and the root part 6c is arranged inside the ball head 4.

[0039] In some embodiments, the vane is made of a white, highly elastic, highly rigid, tear-resistant, shear-resistant, impact-resistant, fatigue-resistant, bendable, low-density foamed plastic sheet, and is cut according to the shape of a natural badminton vane.

[0040] The quill 6 is made of unidirectional fiber-reinforced plastic. For example, it can be made of unidirectional fiber-reinforced plastic directly compounded or modified and compounded with a resin material by one or several high-strength and high-modulus special continuous fibers. The tensile and bending strength of the quill 6 is higher than 0.8 Gpa, and the tensile and bending modulus is higher than 15 Gpa. The cross-sectional thickness of the root part 6c and the shaft part 6b is greater than 0.65 mm, and the cross-sectional bending coefficient is greater than 0.09 mm 3 . The cross-sectional bending coefficient of the quill refers to the cross-sectional bending coefficient when the quill is stressed in its thickness direction.

[0041] In some specific embodiments, the inner side of the quill 6, that is, the side facing the axis, is made of high-strength and high-modulus continuous carbon fiber, and the outer side is made of unidirectional fiber-reinforced plastic compounded with high-strength and high-modulus continuous glass fiber, or high-strength and high-modulus continuous aramid fiber, or high-strength and high-modulus continuous ultra-high molecular weight polyethylene fiber together with a resin material.

[0042] In some specific embodiments, the rachis is made by impregnating continuous fibers with resin and then through pultrusion process to form a unidirectional fiber-reinforced composite profile with a constant cross-section, and then cutting and grinding. The unidirectional fiber-reinforced plastic is directly or modifiedly compounded by one or more high-strength and high-modulus special continuous fibers and resin materials. The special continuous fibers include carbon fiber, glass fiber, aramid fiber, and / or ultra-high molecular weight polyethylene fiber. The modified compounding means adding materials that can reduce density or increase toughness, including hollow glass microspheres, foamed plastic microspheres, and / or physical or chemical blowing agents, toughening agents, in the resin substrate before or during compounding.

[0043] In some other specific embodiments, the rachis is made by impregnating unidirectional strip fiber prepreg with resin, laminating, heating and pressurizing for curing, and then cutting and grinding.

[0044] The artificial badminton of the embodiments of the present application has basically the same quality, quality distribution, stiffness and elasticity as natural high-quality goose or duck feathers, as well as the same flight performance, and has higher bending strength and resistance to impact, shear, tear and fatigue, has excellent durability, and can also be mass-produced at low cost.

[0045] As an alternative embodiment of the present disclosure, in the above embodiment, the bonding layer bonds the inner vane and the outer vane together and wraps the rachis part 6b and the barb part 6a. Specifically, the bonding layer 7c can be an elastic hot-melt adhesive bonding film or a hot-melt adhesive non-woven fabric bonding film web with a thickness of 5-25 μm that is respectively bonded to the inner and outer layers; or, the bonding layer can be composed of two parts, one part is a hot-melt adhesive layer coated on the rachis part and the barb part, and the other part is in the shape of a thin film and is adapted to the shape of the vane. Such a setting can reduce the weight of the head of the artificial feather to meet the strict requirements of the artificial badminton for weight distribution.

[0046] The inner vane 7b and the outer vane 7a can respectively be selected from one of the foamed or micro-foamed polyethylene EPE, foamed polypropylene EPP, foamed polystyrene EPS films, or two different ones; EPP, which is more similar to natural feathers in appearance, or micro-foamed MPP, or EPS film can be used as the outer vane. The vane can be made by autoclave slicing process, or extrusion process, or extrusion blow molding process.

[0047] As an alternative embodiment of the present application, in the above embodiment, the thickness T of the barb part 6a decreases in the direction towards the top of the vane, in order to reduce the weight of the head of the feather and maintain the strength and stiffness of the rachis, so that it better conforms to the deformation and air resistance characteristics of natural feathers during the hitting and flying of the badminton.

[0048] In order to make the artificial badminton of the embodiments of the present application conform to the flight trajectory and flight attitude of the badminton made of natural feathers, the sum of the weights of the head of the vane and the rachis part is between 40 and 75 mg; the center of gravity G of the artificial badminton is at a position 3 to 7 mm away from the ball head on the axis of the skirt.

[0049] In order to increase the strength of the rachis, the cross-section of the rachis is square or rectangular, and the flexural coefficient of the cross-section at the middle position of the rachis part is 0.5 to 0.7 times that of the cross-section at the bottom of the rachis part.

[0050] In order to better fix the artificial feathers, inclined holes 4c that are equally distributed circumferentially and equal in number to the artificial feathers on the skirt 3 are formed on the back of the ball head 4. Glue is injected into the inclined holes 4c, or after applying glue to the root of the artificial feather, it is inserted into the inclined holes 4c for fixation, and then glue is applied at the intersection of the root of the feather and the back plane of the ball head for reinforcement. The inclined holes 4c are distributed within the longitudinal depth of the tail 4b of the ball head, and the bottom of the inclined holes 4c is located at the bottom of the head of the ball head.

[0051] In order to better improve the flight performance of the artificial badminton, there are overlapping parts between the vanes of adjacent artificial feathers on the skirt. The present utility model proposes that a continuous or discontinuous cutting line 7d with a total length of 5 mm to 20 mm is arranged near the rachis and along the direction of the rachis at the middle position of the vane part on the inner side of the overlap, so as to solve the "reverse feather" phenomenon that easily occurs after the vane of the artificial badminton is struck.

[0052] The fiber characteristics of the rachis are introduced below.

[0053] Glass fiber GF: It is an inorganic fiber with glass as the raw material, relatively cheap in price, and has good impregnation in resin. The filament diameter is from a few microns to more than twenty microns, and there are many types. High-strength and high-modulus E glass fiber or S glass fiber is preferred. Due to its relatively large density and low elastic modulus, it is used as the main or auxiliary material for the rachis of mid- to low-end artificial badminton in this application.

[0054] Carbon fiber CF is a special fiber with a carbon content higher than 90%. The filament diameter is 5 to 7 microns. According to its mechanical properties, it is divided into two categories: high-strength and high-modulus. Commonly used high-strength carbon fiber T300 or T700 has good rigidity, but its toughness and impact resistance are slightly insufficient. The newly launched T1000 / T1100 has a strength exceeding 6 GPa, a modulus exceeding 300 GPa, and a fracture elongation rate reaching 2.2%. It is used as the main material for the rachis of mid- to high-end artificial badminton in this application.

[0055] Aramid fiber AF, also known as aromatic polyamide fiber. Among them, the commonly used para-aramid has a medium density, good toughness, impact resistance, and good comprehensive performance. It is commonly used as a bulletproof material and is used as an auxiliary material for the shafts of medium-high-end and high-end artificial badminton in this application.

[0056] High-strength and high-modulus polyethylene fiber UHMWPEF, that is, ultra-high molecular weight polyethylene fiber, has the lowest density, good toughness, and impact resistance, but its impregnation, adhesion, compressive properties, and heat resistance with resin materials are relatively poor. It is used as an auxiliary material for the shafts of high-end artificial badminton in this application.

[0057] In addition to these several common high-strength and high-modulus fiber materials, with the progress of technology, newer and stronger fiber materials have emerged. For example, a PBO Zylon HM fiber material. If price factors are not considered, its performance indicators are also very suitable for making the shafts.

[0058] Comparison table of the mechanical properties of various high-strength and high-modulus special fibers:

[0059]

[0060] The mechanical parameters of the above special fibers will have certain differences due to different production manufacturers using different materials and processes.

[0061] The continuous fibers described in this application refer to the fibers in the shaft that are continuous from beginning to end without interruption. The material for making the shaft described in this application is a unidirectional fiber-reinforced composite plastic formed by the combination of continuous fibers and resin materials. Its tensile and bending strengths, tensile and bending moduli, as well as impact and fatigue resistance in the fiber direction are much better than those of composite plastics reinforced with short-cut fibers and long fibers.

[0062] The resin materials for making the shaft described in this application include thermosetting resins and thermoplastic resins. Thermosetting resins need to be modified according to the characteristics of different fiber materials, including but not limited to epoxy resins, unsaturated polyester resins, vinyl ester resins, etc., with a wide variety of varieties. Among them, epoxy resins have strong adhesion and stable performance, but are hard and brittle, and have relatively poor impact strength, so toughening modification treatment is required. Thermoplastic resins include but not limited to polypropylene, nylon, polyurethane, etc., which have good toughness, impact resistance, can be reused, and are relatively environmentally friendly, but the process is relatively complex and the production cost is relatively high.

[0063] The resin-modified composite proposed in this application is aimed at using glass fibers with low cost, small modulus, and large density, or carbon fibers with large density and brittleness as reinforcing fibers. To improve the stiffness and toughness of the quill under a given weight condition, a density reduction and toughening modification is adopted, that is, adding materials such as hollow glass microspheres, foamed plastic microspheres, physical or chemical foaming agents, and toughening agents with a volume percentage not higher than 30% into the resin. This can significantly reduce the density of the composite material. That is, in the case of unchanged weight, the cross-sectional area increases, the flexural section modulus increases, and the flexural strength, stiffness, and toughness of the quill all increase accordingly.

[0064] There are various composite process methods for the continuous long fibers and resin materials described in this application, including but not limited to injection molding, molding, resin transfer molding (RTM), hot lamination, pultrusion, etc. Among them, pultrusion and lamination are preferably selected as the two composite production processes.

[0065] The quill profile preferably produced by the pultrusion process in this application has a rectangular cross-section, preferably a square cross-section. The reason is that in the pultrusion process of small-sized profiles about 1 mm, circular and square cross-sections are easy to manufacture and produce. And when the cross-sectional areas are the same, the flexural section modulus of the square is 16% higher than that of the circular. The thickness requirement of the quill profile is not less than 0.65 mm, and the flexural section modulus is not lower than 0.09 mm 3 , ensuring that the ball skirt has high strength and stiffness. The structure of the vane part is designed with variable thickness, considering that the force characteristics of the vane part are similar to those of a cantilever beam. Using the approximate equal-strength design concept, under the premise of ensuring the strength and stiffness of the vane part, the mass is minimized, and the contact area with the vane is maximized. Noting that when the quill made of fiber-reinforced resin material is subjected to a bending moment, the outer fibers are subjected to tensile force and filament breakage and structural delamination occur, which are the main reasons for the failure of the composite quill. Therefore, this application proposes a single-sided thickness reduction, and the thickness reduction surface is set on the inner side of the vane to avoid exacerbating the filament breakage and delamination phenomena caused by the thickness reduction.

[0066] In addition to the technical solution of using a single continuous fiber for reinforcement, the present application also proposes to fabricate the rachis by using profiles in which several different fibers are combined with resin. For example, carbon fiber is used as the main body and placed inside the rachis, while glass fiber, aramid fiber or high-strength high-modulus polyethylene fiber is placed outside the rachis. This is because carbon fiber has sufficient rigidity but insufficient toughness and its impact resistance is not strong enough. When the racket strikes forcefully, especially when it is abnormally struck by the racket frame, it is prone to breakage. Therefore, one of the other three fiber materials with high strength, good flexibility, impact resistance, but lower compressive strength and elastic modulus is arranged outside the rachis to bear the tensile stress and buffer the impact force, achieving the effect of complementing each other's strengths and weaknesses, combining rigidity and flexibility, and making the rachis have better durability. At the same time, using a combination of two different fiber materials is also an effective method to reduce costs on the premise of ensuring the given flight performance. For example, glass fiber is inexpensive but has a low elastic modulus and a large specific gravity. If all glass fiber is used, the rachis will lack rigidity and affect flight stability; using a combination of glass fiber and carbon fiber can better balance the contradiction between performance and cost.

[0067] To test the actual effect of the rachis of the present application, the utility modeler referred to the actual stress state of the feather rachis in badminton movement as a cantilever beam and proposed a unified simple measurement method for the mechanical properties of the rachis: Set the length of the barb to 40 mm, semi-rigidly fix the shaft part, and apply a vertical force at the top of the barb to measure the flexural strength and flexural rigidity of the barb part. When the deformation amount at the top of the barb is 20 mm, the applied force (g) is the equivalent value of the flexural rigidity, and the applied force (g) when the barb fails or breaks is the equivalent value of the flexural strength.

[0068] The applicant produced four different rachis samples by pultrusion process and machining. The cross-sectional shape WxT of the shaft part, that is, the bottom of the barb, is 0.9x0.9 mm, and the cross-sectional shape WxT of the top of the barb is 0.9x0.4 mm. The material density is controlled at 1.35 - 1.5 g / ml by methods such as density reduction and modification.

[0069] Sample 1: Unidirectional continuous glass fiber density-reduced and modified epoxy resin composite rachis;

[0070] Sample 2: Unidirectional continuous T300 carbon fiber reinforced unsaturated polyester resin composite rachis;

[0071] Sample 3: Unidirectional continuous T700 carbon fiber reinforced unsaturated polyester resin composite rachis;

[0072] Sample 4: Unidirectional continuous glass fiber and T700 carbon fiber combined reinforced unsaturated polyester resin composite rachis.

[0073] Mechanical property comparison table:

[0074]

[0075] In the above table, the anti-creep, anti-impact and anti-fatigue properties are ranked from medium, good, excellent to outstanding, and the comprehensive score has a maximum of 10 points.

[0076] Since the mechanical properties of natural feathers are related to many factors such as variety, origin, and breeding cycle, the discreteness is relatively large, and the data in the table are the average values of incomplete statistics.

[0077] The quill stems produced in this application through material selection and combination, structural design optimization, and process innovation have a 30%-120% higher bending strength of the barbs compared with natural duck feathers, natural goose feathers, and existing artificial feathers, and the anti-creep, anti-impact, and anti-fatigue properties are significantly improved, indicating that their durability can be greatly improved. The bending stiffness of the barbs is similar, making their flight characteristics similar to those of natural feathers.

[0078] The vane blades described in this application are made of low-density foamed films with good rigidity, resilience, impact resistance, tear resistance, and bending fatigue resistance. In theory, all plastic varieties can be made into foamed materials, but there are significant differences in the process difficulty, manufacturing cost, and product characteristics of foaming different materials. At the current level of foaming technology, polyethylene (PE), polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC), polyurethane (PU), polyethylene terephthalate (PET), etc. can all achieve low-density foaming. In particular, the more environmentally friendly supercritical foaming technology using CO2 and N2 as physical blowing agents, as well as the better-performing microcellular foaming technology, are becoming increasingly mature, laying the foundation for the application of various foamed films in artificial badminton.

[0079] Through the analysis of the characteristics of various foamed films, in-depth research on the performance requirements of badminton vanes, and cost comparison, this application optimally selects the following three foamed films that can be applied to badminton vane blades from numerous foaming materials, and obtains a better solution through material modification and material combination.

[0080] The EPE foamed film has a density as low as 10mg / ml and a low cost. At a density of 20g / ml, its tensile, compressive, and bending strengths are all higher than 0.15Mpa, the tear strength is greater than 4.0N / mm, and it has good impact strength, but its stiffness and resilience are insufficient, and the 10% compression deformation pressure is less than 80Kpa. Even through modification, such as chemical cross-linking modification (XPE) and radiation cross-linking modification (IXPE), it still cannot independently meet the performance requirements of medium and high-grade badminton vanes. In this application, in addition to being used alone as low-grade badminton vanes, it is used as the inner vanes of medium and high-grade badminton vanes.

[0081] The mechanical indexes such as high rigidity, high elasticity, and high strength described in this application are based on ordinary EPE foam. This application particularly proposes using low-density foamed, especially microcellular foamed polypropylene EPP (MPP), and polypropylene styrene EPS (MPS) foam to make the vane, and the two have an appearance and performance closer to that of natural feathers. Currently, the mature foaming process can already achieve a foaming ratio of more than 30 times. This application preferably uses EPP (including MPP) or EPS (including MPS) foam with a density of 20-60 mg / ml and a thickness of 0.2-1.2 mm to make the vane. Among them, EPP (MPP) has relatively good strength, stiffness, resilience, impact resistance, toughness, and fatigue resistance, but its foaming process is a bit more complex than the previous two. EPS (MPS) foam has excellent flexural stiffness, resilience, and fatigue resistance to bending, but its tear strength and toughness are not ideal. This application provides reinforcement through toughening modification of the EPS material, pairing with the following EPE / MPP foam, and a specially designed intermediate adhesive film.

[0082] This application also proposes using a combination of two different materials of foamed films to make the inner and outer vanes of the vane, which can enable the feather vane to obtain better comprehensive performance. The pairwise combination of the three preferred EPE, EPS, and EPP (including the corresponding microcellular foamed materials) in this application can form 6 different vane blades: EPE-EPE, EPS-EPE, EPP-EPE, EPS-EPS, EPS-EPP, EPP-EPP, and they are used as low-grade, medium-grade, and high-grade badminton respectively according to their flight performance, durability, and appearance to suit different application scenarios and market demands. The following table is the performance comparison of the EPS-EPE, MPP-EPE, and EPS-MPP composite films in this application with the EPE-EPE vane on the market:

[0083] The inner and outer vanes adopt an equal-thickness sandwich film combination, and the areal density is controlled at 6-8 mg / cm 2 .

[0084] The mechanical performance indexes such as the strength and stiffness of the film material are strongly correlated with its density, so the index values in the table are also incomplete statistical value ranges.

[0085]

[0086] It can be seen from the table that through the combination of film sheets with different characteristics adopted in this application, the important performance indexes of the vane are greatly improved, and the flight performance and durability of the badminton made of this artificial feather are also correspondingly greatly improved.

[0087] The design of the double - sheet foamed plastic film described in this application, which wraps the shaft and branches of the fiber - reinforced composite resin rachis, can better buffer the hitting force of the racket on the rachis, making up for the deficiency in impact resistance when the rachis uses carbon fiber and thermosetting epoxy resin materials. At the same time, the fiber - reinforced rachis is relatively thin. When using carbon fiber, the rachis is black. Through the white covering and widening at the neck of the vane, the wind - resistance characteristics and appearance of the rachis can be improved, making it look more like a natural feather. The vane designed in this way consists of two parts. The part corresponding to the position of the branches is the head of the vane, with a surface area of 4.0 - 5.5 cm 2 , and the part corresponding to the position of the shaft is called the neck of the vane, with a surface area of 0.6 - 0.8 cm 2 .

[0088] The preferred solution of this application, which is to set a hot - melt adhesive film between the double - sheet foamed films, is also an effective method to improve the tear - resistance strength of the vane. If it is just simple glue - coating bonding, it is difficult to control its thickness and uniformity. Moreover, without the transverse cross - linking effect of the film, its effect on improving the tear - resistance strength of the vane is limited. Using a hot - melt adhesive film, especially a non - woven fabric - based hot - melt adhesive film, has a simple process and good consistency, and can greatly improve the tear - resistance strength of the vane, thus improving the durability of the badminton. In some cases, one of the two vanes can also be cancelled, or it can be combined with the non - woven fabric - based adhesive film into one.

[0089] As mentioned above, the center - of - gravity position of the badminton is crucial for its flight performance. Therefore, this application has designed many technical solutions to reduce the weight of the branch part of the vane, so as to ensure that the center of gravity G of the whole badminton is located on the center line A of the frustum - shaped skirt, and the distance from the back plane of the ball head is between 3 - 7 mm, preferably within the range of 4 - 6 mm.

[0090] There are differences in structure and aerodynamic performance between artificial feathers and natural feathers. This application proposes a method to adjust the flight performance of the badminton by adjusting the deflection angle C of the feathers. The deflection setting of the feathers is to generate a tangential force during the flight of the feathers to drive the badminton to rotate, and its gyroscopic effect is beneficial to the stability of the badminton flight trajectory. The rotation speed of natural badminton under standard wind speed is generally controlled at 300 - 500 rpm, while the rotation speed of artificial badminton under standard wind speed will be adjusted according to the blade resistance characteristics. The size of the deflection angle is the main factor determining the rotation speed of the badminton, thus having a greater impact on the flight performance.

[0091] After the feather deflection setting, an ordered stack is formed between adjacent barbs. When the vane is deformed after being struck, the stack order will be disrupted. The vane of natural feathers is composed of countless filaments, which can be freely separated and combined, enabling the vane to quickly return to the given stack order. However, the vane of artificial feathers is a monolithic sheet, different from that of natural feathers. It is difficult for the vane to return to the original stack order after deformation, that is, the "fluffed feather" phenomenon occurs. Even after improving the stiffness and elasticity of the rachis and vane in this application, it still occurs occasionally. Therefore, this application further proposes to set continuous or discontinuous cutting lines along the direction of the rachis in the middle part of the inner vane of the stack, such as a cutting line of 2x(interrupted 8mm + continuous 5mm) starting from 8mm away from the tip of the blade, to weaken the recovery resistance caused by the bending rigidity of the inner blades of adjacent vanes and facilitate the rapid reset of the outer barbs.

[0092] The following further describes this application with specific embodiments.

[0093] Example 1: Badminton with a continuous fiberglass GF unidirectional density-reducing modified reinforced composite plastic rachis

[0094] In the embodiment of this application, the rachis (6) is made of continuous glass fiber unidirectional reinforced resin composite material. A certain domestic ultra-high modulus fiberglass with a tensile strength of 3.3 Gpa and a modulus of 100 Gpa is selected and compounded with epoxy resin and density-reducing hollow glass microspheres by pultrusion process in a volume percentage of 35:40:25. Its density is 1.36 g / ml, the tensile strength is higher than 1.0 Gpa, and the tensile modulus is higher than 20 Gpa. The rachis (6) designed according to this application has a length of 75 mm, a square cross-section of 0.9x0.9 mm, and a bending section modulus of 0.12 mm 3 , the thickness of its barb part (6c) decreases from 0.9 mm at the bottom to 0.4 mm at the top, the weight is 32 mg, and the maximum bending moment Mm = 12 N.cm that the bottom of the barb can withstand exceeds the bending moment value that the barbs of ordinary duck feathers can withstand, and its toughness is also higher than that of goose and duck feathers.

[0095] The outer and inner layers of the vane can be selected as EPE foam, and the intermediate bonding film is a non-woven fabric-based hot melt adhesive film. The composite vane areal density is 6.0 - 6.5 mg / cm 2 , the blade area is 4.5 - 5 cm 2 , and when the vane quality is 30 - 33 mg. The quality of the vane head plus the barb part is 60 - 65 mg.

[0096] The badminton produced from this artificial feather has flight performance equivalent to that of medium-quality duck feather badminton. At the 4-star level, its durability is better than that of high-quality duck feathers, reaching the 5-star level, and it is suitable for entry-level amateur badminton enthusiasts. It is cost-effective.

[0097] Example 2: Badminton with a continuous carbon fiber unidirectional reinforced composite plastic rachis

[0098] In the embodiment of the present application, the rachis is made of continuous carbon fiber unidirectionally reinforced resin composite material. In the present application, carbon fiber such as T700 with a volume ratio of 40% and equivalent or better performance than T300-3k is compounded with toughened and modified vinyl ester resin VE by pultrusion process into a plastic profile. The density is about 1.34 g / ml, the tensile strength > 1.4 GPa, and the tensile modulus > 40 GPa. The shape design of the rachis is the same as that in Embodiment 1. The weight of the vane part is 31 mg, and the maximum bending moment Mm that the bottom of the vane can withstand > 16 N·cm, exceeding the bending moment value that can be withstood by high-quality goose and duck feathers, and the stiffness is higher than that of high-quality goose feathers.

[0099] The outer layer of the vane is equipped with EPS foam, the inner layer is EPE, and the intermediate bonding film is a non-woven fabric-based hot-melt adhesive film. The mass of the vane plus the rachis part is less than 65 mg.

[0100] The badminton produced from this artificial feather has the same flight performance as that of a high-quality goose feather ball, which is 5-star. The rachis has good impact resistance, but it will still break when being strongly hit. Its durability is 5-star, and it is suitable for badminton enthusiasts at the intermediate and advanced amateur levels.

[0101] Embodiment 3: Badminton with a rachis of continuous carbon fiber plus continuous glass fiber unidirectionally reinforced and density-reduced modified composite plastic

[0102] In the present application, continuous carbon fiber, continuous glass fiber, epoxy resin and hollow glass microspheres with performance equivalent to or higher than that of T300 are compounded into a unidirectionally reinforced plastic profile by pultrusion process according to the volume percentages of 27.5:12.5:50:10, and the glass fiber is mainly distributed on the outer side of the rachis, and the carbon fiber is distributed on the inner side of the rachis. The density of the composite profile is 1.34 g / ml, and the other designs of the vane are the same as those in Embodiment 2. The mass of the vane plus the rachis part is 63 mg.

[0103] Its performance indexes are close to those in Embodiment 2, and the flight performance is 5-star. The rachis has good impact resistance, but both the glass fiber and the carbon fiber are still brittle materials and will still break when being strongly or abnormally hit. The durability of the badminton is at the 6-star level, and it is suitable for intermediate and advanced amateur badminton enthusiasts to practice or play games.

[0104] Embodiment 4: Badminton with a rachis of continuous carbon fiber plus continuous aramid fiber unidirectionally reinforced composite plastic

[0105] This application uses continuous carbon fiber and continuous aramid fiber with performance equivalent to or higher than that of T700 (such as T800 / T1000, etc., the diameter of ultra-high-strength carbon fiber is generally 5um, the minimum wire harness is 12K, and the wire harness density is 400g / tex), and PP resin is compounded into a unidirectional reinforced plastic profile by extrusion impregnation + pultrusion process with a volume ratio of 30:20:50. The aramid fiber is mainly distributed on the outside of the quill, and the carbon fiber is distributed on the inside. The density of the composite profile is 1.30g / ml, and the tensile strength > 1.4Gpa. The cross-section of the quill is set as a square with 0.94x0.94mm, and the flexural section modulus = 0.138. The maximum bending moment Mm that the bottom of the barb can withstand > 20Ncm, which is twice the bending moment that general natural feathers can withstand. The thickness of the top cross-section of the barb part is 0.40mm, and the weight of the barb part is 31mg.

[0106] Both the outer layer and the inner layer of the vane use MPP film, with excellent comprehensive performance. The areal density of the composite vane is 5.4mg / cm 2 , and the mass of the vane plus the barb part is 60 - 65mg.

[0107] Its flight performance is better than that of Example 3, being 6-star; the quill has good impact resistance, and the durability of the badminton is improved to the 7-star level and will not break easily even when being strongly and abnormally hit. It is suitable for use by relatively high-level badminton enthusiasts or even professional athletes during practice or competition.

[0108] Example 5: Badminton with a unidirectional reinforced composite plastic quill of continuous carbon fiber plus continuous high-strength and high-modulus polyethylene fiber

[0109] This application is compounded by laminating and molding or a specially designed pultrusion process with 25% volume ratio of continuous unidirectional carbon fiber pre-impregnated cloth with performance equivalent to or higher than that of T800 (such as T1000 / T1100, etc.), 20% volume ratio of continuous high-strength and high-modulus polyethylene fiber unidirectional pre-impregnated cloth and resin. Since polyethylene fiber is not resistant to high temperature and has poor adhesion to other resins, surface modification treatment must be carried out, and the curing temperature of the resin must be reasonably selected and strictly controlled, so that the high-strength and high-modulus polyethylene fiber is mainly distributed on the outside of the quill. The density of the composite rod is 1.25g / ml, the cross-section is set as a square with 0.96x0.96mm, and the flexural section coefficient is 0.16, having excellent comprehensive performance of bending strength, rigidity, elasticity, toughness, impact resistance and fatigue resistance, and it is a badminton with unbreakable feathers. The vane uses MPS + MPP + non-woven fabric-based hot melt adhesive composite.

[0110] The flight performance of the artificial badminton in this example is 7-star, and the durability of the badminton can also reach the 7-star level. It is suitable for use by high-level badminton enthusiasts or professional athletes during practice or competition.

[0111] The above specific embodiments do not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub - combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. An artificial badminton, characterized in that: include: A ball skirt and a ball head, wherein the ball skirt comprises a plurality of artificial feathers and at least two supporting coils, the artificial feather comprises a quill and a feather leaf, the quill comprises a feather root, a feather shaft and a feather branch, and the feather leaf comprises an inner feather leaf, an outer feather leaf and a middle adhesive layer; The inner feather blade and the outer feather blade are bonded together by the intermediate bonding layer, and the feather stem and the feather branch are covered; the feather root is arranged in the ball head, and the supporting coil fixes the feather stem; The feather stalk is made of unidirectional continuous fiber reinforced composite plastic, the longitudinal tensile and bending strength of the feather stalk is higher than 0.8Gpa, the longitudinal tensile and bending modulus is higher than 15Gpa, the cross-sectional thickness of the feather root and the feather stem is greater than 0.65mm, and the cross-sectional bending coefficient is greater than 0.09mm 3 ; The feather blade is made of a low-density, high-strength and high-rigidity foamed plastic sheet.

2. The artificial badminton shuttlecock according to claim 1, characterized in that: The thickness of the barb portion decreases toward the top of the pinna.

3. The artificial badminton shuttlecock according to claim 2, characterized in that: The cross section of the barb is square or rectangular, and the bending coefficient of the cross section at the longitudinal middle position of the barb is 0.5-0.7 times the bending coefficient of the cross section at the bottom of the barb.

4. The artificial badminton shuttlecock according to claim 3, characterized in that: The sum of the weights of the head of the feather leaf and the barb is between 40-75 mg; the center of gravity of the artificial badminton is located at a position 3-7 mm away from the ball head on the axis line of the ball skirt.

5. The artificial badminton shuttlecock according to claim 1, characterized in that: The unidirectional continuous fiber reinforced composite plastic is formed by directly compounding or modifying one or more high-strength and high-modulus special continuous fibers with a resin material. The special continuous fibers include carbon fibers, glass fibers, aramid fibers, and ultra-high molecular weight polyethylene fibers.

6. The artificial badminton shuttlecock according to claim 5, characterized in that: The modified composite refers to adding materials that can reduce density or increase toughness to the resin matrix before or during the composite process, including hollow glass microspheres, foamed plastic microspheres, and / or physical or chemical foaming agents and toughening agents.

7. The artificial badminton shuttlecock according to claim 5, characterized in that: The feather stalk is made of unidirectional continuous fiber reinforced plastics which are compounded by pultrusion or lamination of one or more of the high-strength and high-modulus special fibers and resin.

8. The artificial badminton shuttlecock according to claim 1, characterized in that: The outer feather blades and the inner feather blades are respectively made of the same or two different kinds of foamed or microporous foamed polyethylene EPE, polypropylene EPP, and polystyrene EPS foam films.

9. The artificial badminton shuttlecock according to claim 1, characterized in that: The middle adhesive layer is a single-layer or double-layer elastic hot-melt adhesive film or a hot-melt adhesive non-woven fabric adhesive film with a thickness of 5-25 um.

10. The artificial badminton shuttlecock according to claim 1, characterized in that: The back of the ball head is provided with inclined holes evenly distributed along the circumference, the number of which is equal to the number of the artificial feathers on the ball skirt. Glue is injected into the inclined holes, or glue is applied to the base of the artificial feathers and then inserted into the inclined holes for fixation, and then glue is applied to the intersection of the base and the back plane of the ball head for reinforcement.

11. The artificial badminton shuttlecock according to claim 1, characterized in that: The feather blades of adjacent artificial feathers on the ball skirt overlap each other, and a continuous or discontinuous cutting line with a total length of 5mm-20mm is arranged in the middle of the inner feather blade close to the feather stalk and along the feather stalk.

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