A pick-up racket with different elastic coefficients on two sides

Abstract

The present application relates to a kind of pick rackets with different elastic coefficients on two sides, belonging to the technical field of sports equipment.The pick racket includes handle, inner core layer, first surface layer and second surface layer;The first surface layer is arranged on one side of the inner core layer;Second surface layer is arranged on the other side of the inner core layer, and is arranged opposite to the first surface layer;The elastic coefficient of the first surface layer and second surface layer is different, the elastic coefficient of the first surface layer is 0.4-0.55;The elastic coefficient of second surface layer is 0.3-0.45.The present application realizes the pick racket with different elastic coefficients on two sides, different faces are used by athletes to hit the ball, different experiences are brought, and different elastic racket faces are flexibly selected for use in attack and defense conversion.

Description

Technical Field

[0001] This invention belongs to the field of sports equipment technology, specifically, it relates to a Peak racket with two sides having different elastic coefficients. Background Technology

[0002] Pickleball is a net-based competitive sport. The court size is similar to a badminton court, but the net is slightly lower than a tennis net, and the racket is slightly larger than a table tennis racket. With its user-friendly rules, flexible pace, and strong social element, pickleball has become a global phenomenon in recent years, a typical form of fitness for all.

[0003] Peak rackets typically consist of three parts: the handle, the core, and the racket face. The core is the racket's core structure. Currently, most Peak rackets use high-polymer materials for their cores, resulting in advantages such as light weight, high strength, and good responsiveness, providing basic elasticity and shock absorption. The racket face covers both sides of the core and is the hitting layer that directly contacts the Peak ball. Its material and performance directly determine the feel, spin, and ball speed. High-end Peak rackets widely use carbon fiber composite materials for their racket faces, offering advantages such as high specific strength, high specific modulus, and good dimensional stability. This provides excellent elastic feedback and shot control, while also giving the racket good durability.

[0004] However, existing Peak rackets use the same material system and structural design on both sides, resulting in similar elasticity coefficients and a basically identical feel when hitting the ball. In actual matches, players cannot flexibly choose to use different elasticity sides during offensive and defensive transitions based on changes in the game situation and tactical needs. When acceleration is needed for an attack, there is a lack of sufficient power assistance, and when control of the landing point is needed, there is a lack of sufficient shock absorption.

[0005] Given the successful experience of using different rubbers on each side of a table tennis racket to achieve "differentiated forehand and backhand shots," some technicians attempted to transfer this technical approach to Peak rackets. However, the construction and usage of Peak rackets differ fundamentally from table tennis rackets: Peak rackets feature a composite structure where the racket face is tightly bonded to the inner core using a heat-pressing process to obtain clearer feedback upon impact. Furthermore, Peak rackets are larger, and like tennis rackets, they require two-handed use. Simply using different densities or materials on one side of the racket face would result in significant differences in weight distribution, thickness, and overall mass balance on both sides. This imbalance, when players quickly switch between hitting surfaces during a match, directly affects the accuracy of racket face angle control and the consistency of shot feel, leading to inconsistent performance and even increasing the risk of wrist and shoulder injuries.

[0006] In conclusion, how to achieve differentiated configurations of elasticity coefficients on both sides of a Peak racket is a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0007] In order to solve the technical problems mentioned in the background art, the purpose of this invention is to provide a Peak racket with two sides having different elastic coefficients.

[0008] The objective of this invention can be achieved through the following technical solutions: A Peak racket with two sides having different elastic coefficients, the racket comprising: A handle for the player to grip; The inner core layer is located at one end of the handle. One side of the inner core layer has a raised structure, while the other side does not. When the racket is impacted by the peak ball, the side with the raised structure provides additional compression space and energy storage path, which can generate higher rebound force and faster ball speed, thus achieving the technical effect of different elastic coefficients on two sides.

[0009] A first surface layer is disposed on one side of the inner core layer; The second surface layer is disposed on the other side of the inner core layer and is disposed opposite to the first surface layer; Both the first and second surface layers are made of modified EP-CF (epoxy-carbon fiber composite) material, but the elastic moduli of the first and second surface layers are different. The elastic moduli of the first surface layer is 0.4-0.55, and the elastic moduli of the second surface layer is 0.3-0.45. The first and second surface layers contain different color masterbatch materials, which makes the first and second surface layers present different colors.

[0010] Using the same material system for both sides of the racket ensures that the mass distribution and thickness on both sides remain basically consistent, eliminating racket imbalance caused by differences in racket surface materials; while different color markings make it easier for players to quickly identify whether they are using the side with higher elasticity (convex dot side) or the side with lower elasticity (flat side) during the game, so as to achieve accurate execution of tactical intentions.

[0011] The modified EP-CF pad surface is formed by hot pressing a modified epoxy adhesive with carbon fiber woven fabric. Specifically, the modified epoxy adhesive uses epoxy resin as the main adhesive material, and its specific components are: 10-15wt% modifier, 8-12wt% diluent, 4.5-6.2wt% curing agent, 0.6-0.8wt% defoamer, 0.3-0.4wt% leveling agent, and 0.5-0.7wt% pigment, with the balance being epoxy resin.

[0012] The modifier is a diepoxy compound containing a crown ether macrocyclic structure, and the specific preparation method is as follows: Step A1: Mix diaza-18-crown-6, bromoalkanol and tetrahydrofuran, then add triethylamine as an acid-binding agent, purge with nitrogen for protection, heat to 65±2℃ and reflux for 12-18h, filter to remove salt after reaction, and recover tetrahydrofuran by rotary evaporation to obtain intermediate. Step A2: Mix the intermediate, tetrabutylammonium bromide and dimethylacetamide, raise the temperature to 80-95℃, slowly add epichlorohydrin and react for 5-8 hours, then cool down and control the temperature in a water bath at 40-50℃, add sodium hydroxide aqueous solution and continue the reaction for 2.5-3.5 hours. After the reaction is complete, add deionized water to wash, separate the aqueous phase and vacuum dry to obtain the modifier.

[0013] Furthermore, in step A1, the molar ratio of diaza-18-crown ether-6 to bromoalkanol is 1:2.1-2.3, and triethylamine accounts for 20-30 wt% of the total amount of both; the bromoalkanol substitutes the active secondary amine in the diaza-18-crown ether-6 molecule to introduce a dibranched alkyl alcohol structure.

[0014] Preferably, the bromoalkanol is one of 4-bromobutanol and 8-bromooctanol.

[0015] Furthermore, in step A2, the molar ratio of the intermediate to epichlorohydrin is 1:1.4-1.6, the amount of tetrabutylammonium bromide is 2.2-3.5 wt% of the total amount of both, the amount of sodium hydroxide is equimolar with that of epichlorohydrin, and the mass fraction of its aqueous solution is 30-35 wt%. The method for manufacturing the Peak racket with different elastic coefficients on both sides is as follows: Step B1: Add modifier, diluent, defoamer, leveling agent, pigment, epoxy resin and curing agent in sequence and mix well. After vacuum degassing, the modified epoxy adhesive is obtained. Step B2: Apply epoxy adhesive to the surface of carbon fiber woven fabric, pre-bake and dry it, then cut it to obtain the modified EP-CF racket face; Step B3: The modified EP-CF racket face is attached to the surface of the inner core layer, and then placed in a mold for hot pressing and curing. After the handle is installed, the Peak racket is made.

[0016] The objective of this invention can be achieved through the following technical solutions: The beneficial effects of this invention are: This invention enables Peak rackets with different elastic coefficients on both sides, allowing athletes to hit the ball using different sides, resulting in different experiences and enabling them to flexibly choose to use different elastic racket faces for hitting the ball during offensive and defensive transitions.

[0017] This invention, based on the inner core layer, employs a differentiated design by incorporating a raised structure on one side of the racket surface while leaving the other side without raised points. This allows the racket to achieve a higher rebound coefficient and faster ball speed on the raised side under the same impact force due to the compression and energy storage effect of the raised points, effectively differentiating the elastic coefficients of the two sides of the same racket. This design does not change the racket face material or significantly alter the racket's balance point or center of gravity, fundamentally solving the technical problem of racket imbalance caused by attempts to achieve double-sided elasticity differentiation through different racket face materials in existing technologies.

[0018] It is particularly important to note that while the raised dot structure provides the racket with the advantage of differentiated elasticity on both sides, it also introduces a new technical problem: when a player hits different points on the raised dot surface, the rebound force spreading from the raised dot creates a large amount of rebound force interference in the contact area, generating micro-regions of uneven rebound force. This results in inconsistent feel when hitting the ball from different points, severely affecting the player's judgment of the ball's direction and landing point. If this problem is not solved, the tactical value of the differentiated elasticity coefficient design on both sides will be greatly reduced. This invention uses a modified EP-CF racket face prepared with a crown ether macrocyclic modified epoxy adhesive, perfectly solving the above-mentioned problem. Its mechanism of action is as follows: During the impact process, the convex side of the racket face first bears the high-speed impact from the pickle. The impact energy is conducted through the racket face to the convex structure in the inner core. The convex points store elastic energy and generate rebound force during compression and deformation. However, due to the discrete distribution characteristics of the convex array, the rebound force diffuses outward from each convex point. At this time, the crown ether macrocyclic structure bonded in the modified EP-CF racket face plays a key role in "secondary deformation": the crown ether macrocyclic structure has a deformable cavity structure. When the impact force exceeds a certain threshold, the crown ether ring undergoes dynamic and reversible conformational adjustment. Specifically, in the energy release stage after the initial convex compression, the intense rebound stress could have led to local stress concentration and energy spikes inside the racket face; however, through the synergistic effect of the compressibility of its cavity and its dynamic coordination ability, the crown ether macrocyclic structure can achieve stress redistribution at the molecular level, which is equivalent to embedding countless micro-nano-scale "molecular-scale stress buffers" in the epoxy resin crosslinking network. These "molecular buffers" preferentially undergo reversible conformational contraction and expansion in the energy peak region, decomposing concentrated stress into a more evenly distributed energy flow, achieving "uniform output" of rebound force and "soft touch transmission", resulting in clear ball feedback, accurate ball landing point, and facilitating precise ball handling by players. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the structure of the Peak racket with different elastic coefficients on both sides according to the present invention. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] Example 1: Preparation of a Peak racket with two sides having different elastic coefficients. The specific implementation process is as follows: 1) Preparation of modifier 1.1 Mix diaza-18-crown ether-6, 4-bromobutanol, and tetrahydrofuran, then add triethylamine as an acid-binding agent and stir to mix. Under nitrogen protection, heat to 65±2℃ and reflux for 12 h. The mixture contains diaza-18-crown ether-6: 20 mmol, 4-bromobutanol: 42 mmol, triethylamine: 20 wt% of the total amount of the two, and tetrahydrofuran: 150 mL. After the reaction is complete, filter to remove salts, and rotary evaporate to recover tetrahydrofuran to obtain the intermediate.

[0023] 1.2. Mix the intermediate, tetrabutylammonium bromide, and dimethylacetamide. Heat the mixture to 95°C and slowly add epichlorohydrin. React for 8 hours. Prepare a 30 wt% aqueous solution of sodium hydroxide and deionized water. When the temperature of the reaction system drops to 40°C, maintain the temperature in a water bath. Add the sodium hydroxide aqueous solution and continue the reaction for 3.5 hours. The intermediate is 10 mmol, epichlorohydrin is 16 mmol, sodium hydroxide is 16 mmol, the amount of tetrabutylammonium bromide is 3.5 wt% of the total amount of the intermediate and epichlorohydrin, and dimethylacetamide is 120 mL. After the reaction is complete, add 1 L of deionized water to wash the mixture. After separating the aqueous phase, vacuum dry to obtain the modifier.

[0024] 2) Preparation of modified EP-CF racket face 2.1 A modified epoxy adhesive was prepared by formulation using a two-component epoxy resin as the main adhesive material. The specific components are as follows: The modifier, 10 wt%, was prepared in-house according to this embodiment; Diluent 12wt%, using 501 diluent, the same applies below; The curing agent is 4.5 wt%, using PN-23 type latent curing agent, and the same applies below; Defoamer 0.8wt%, BYK-A 500, the same applies below; Leveling agent 0.4wt%, BYK-333, the same applies below; The pigments, at 0.5 wt%, consist of EPM RX15 red pigment and EP-0057 black pigment, with two color binders formulated in each embodiment. The remainder is epoxy resin, using ESP-135 A / B type resin raw materials, and the same applies below.

[0025] The modifier, diluent, defoamer, leveling agent, pigment, epoxy resin and curing agent are added and mixed in sequence, and then vacuum degassed to obtain the modified epoxy adhesive.

[0026] 2.2. Apply the modified epoxy adhesive at a concentration of 110±5 g / m³. 2 The modified EP-CF racket face is obtained by scraping the coating onto the surface of the carbon fiber woven fabric, pre-drying at 60℃ for 30 minutes, and then cutting.

[0027] 3) Assembly of Peak rackets Reference Figure 1 As shown, a molded inner core layer with single-sided protrusions (bottom diameter 2mm, height 1.0mm, array protrusions with a spacing of 5mm) is taken, and a modified EP-CF racket surface is bonded to both sides. The core is then placed into a mold and hot-pressed and cured at 120℃ and 2.5MPa for 60 minutes. After the handle is installed, a Peak racket is made.

[0028] Example 2: Preparation of a Peak racket with two sides having different elastic coefficients. The specific implementation process is as follows: 1) Preparation of modifier 1.1 Mix diaza-18-crown ether-6, 8-bromooctanol and tetrahydrofuran, then add triethylamine as an acid-binding agent and stir to mix. Under nitrogen protection, heat to 65±2℃ and reflux for 18h; wherein, diaza-18-crown ether-6: 20mmol, 8-bromooctanol: 46mmol, triethylamine: 30wt% of the total amount of the two, and tetrahydrofuran: 220mL; after the reaction is complete, filter to remove salt, and rotary evaporate to recover tetrahydrofuran to obtain the intermediate.

[0029] 1.2. Mix the intermediate, tetrabutylammonium bromide, and dimethylacetamide. Heat the mixture to 80°C and slowly add epichlorohydrin. React for 5 hours. Prepare a 35 wt% aqueous solution of sodium hydroxide and deionized water. When the temperature of the reaction system drops to 50°C, maintain the temperature in a water bath. Add the sodium hydroxide aqueous solution and continue the reaction for 2.5 hours. The intermediate is 10 mmol, epichlorohydrin is 14 mmol, sodium hydroxide is 14 mmol, the amount of tetrabutylammonium bromide is 2.2 wt% of the total amount of the intermediate and epichlorohydrin, and dimethylacetamide is 180 mL. After the reaction is complete, add 1 L of deionized water to wash the mixture. After separating the aqueous phase, vacuum dry to obtain the modifier.

[0030] 2) Preparation of modified EP-CF racket face 2.1 A modified epoxy adhesive was prepared by formulation using a two-component epoxy resin as the main adhesive material. The specific components are as follows: Modifier 15wt%, diluent 8wt%, curing agent 6.2wt%, defoamer 0.6wt%, leveling agent 0.3wt%, pigment 0.7wt%, balance is epoxy resin.

[0031] The modifier, diluent, defoamer, leveling agent, pigment, epoxy resin and curing agent are added and mixed in sequence, and then vacuum degassed to obtain the modified epoxy adhesive.

[0032] 2.2. Apply the modified epoxy adhesive at a concentration of 110±5 g / m³. 2 The modified EP-CF racket face is obtained by scraping the coating onto the surface of the carbon fiber woven fabric, pre-drying at 60℃ for 30 minutes, and then cutting.

[0033] 3) Assembly of Peak rackets Reference Figure 1 As shown, a single-sided convex core layer is molded and molded, and a modified EP-CF racket surface is bonded to both sides. The core is then placed into a mold and hot-pressed and cured at 120℃ and 2.5MPa for 60 minutes. After the handle is installed, a Peak racket is made.

[0034] Example 3: Preparation of a Peak racket with two sides having different elastic coefficients. The specific implementation process is as follows: 1) Preparation of modifier 1.1 Mix diaza-18-crown ether-6, 4-bromobutanol, and tetrahydrofuran, then add triethylamine as an acid-binding agent and stir to mix. Under nitrogen protection, heat to 65±2℃ and reflux for 14h. The mixture contains 20 mmol of diaza-18-crown ether-6, 44 mmol of 4-bromobutanol, 20 wt% of the total amount of both, and 180 mL of tetrahydrofuran. After the reaction is complete, filter to remove salts, and rotary evaporate to recover tetrahydrofuran to obtain the intermediate.

[0035] 1.2. Mix the intermediate, tetrabutylammonium bromide, and dimethylacetamide. Heat the mixture to 90°C and slowly add epichlorohydrin. React for 7 hours. Prepare a 30 wt% aqueous solution of sodium hydroxide and deionized water. When the temperature of the reaction system drops to 40°C, maintain the temperature in a water bath. Add the sodium hydroxide aqueous solution and continue the reaction for 3 hours. The components are: intermediate: 10 mmol, epichlorohydrin: 16 mmol, sodium hydroxide: 16 mmol, tetrabutylammonium bromide: 3.0 wt% of the total amount of intermediate and epichlorohydrin, and dimethylacetamide: 150 mL. After the reaction is complete, add 1 L of deionized water to wash the mixture. After separating the aqueous phase, vacuum dry to obtain the modifier.

[0036] 2) Preparation of modified EP-CF racket face 2.1 A modified epoxy adhesive was prepared by formulation using a two-component epoxy resin as the main adhesive material. The specific components are as follows: Modifier 12wt%, diluent 10wt%, curing agent 5.7wt%, defoamer 0.7wt%, leveling agent 0.4wt%, pigment 0.6wt%, balance is epoxy resin.

[0037] The modifier, diluent, defoamer, leveling agent, pigment, epoxy resin and curing agent are added and mixed in sequence, and then vacuum degassed to obtain the modified epoxy adhesive.

[0038] 2.2. Apply the modified epoxy adhesive at a concentration of 110±5 g / m³. 2 The modified EP-CF racket face is obtained by scraping the coating onto the surface of the carbon fiber woven fabric, pre-drying at 60℃ for 30 minutes, and then cutting.

[0039] 3) Assembly of Peak rackets Reference Figure 1 As shown, a single-sided convex core layer is molded and molded, and a modified EP-CF racket surface is bonded to both sides. The core is then placed into a mold and hot-pressed and cured at 120℃ and 2.5MPa for 60 minutes. After the handle is installed, a Peak racket is made.

[0040] Comparative Example 1 follows the same implementation process as in Example 3, using a mixture of ESP-135 A / B type resin and pigment as a binder, without adding any other components.

[0041] Comparative Example 2 follows the same implementation process as Example 3, but uses diaza-18-crown ether-6 directly instead of the modifier, without adding a curing agent, and the rest is the same.

[0042] The rebound coefficient (PBCoR) is a core indicator for measuring the energy transfer efficiency of a racket during impact. It is defined as the ratio of the ball's velocity to its incident velocity after the racket collides with the pick. The rackets prepared above were tested using a PBCoR testing machine to measure the rebound coefficient at the center of the racket face and in the center of each of the four quadrants. The average value was calculated as the rebound coefficient. Specific test results are shown in Table 1. Table 1. Rebound Coefficient Test Results

[0043] As can be seen from the test data in Table 1, the embodiment yielded rackets with different rebound coefficients on both sides. The rebound coefficient of the convex side was 0.4-0.55, and the rebound coefficient of the flat side was 0.3-0.45.

[0044] The accuracy of bounce landing point is used to evaluate the consistency of the ball's direction of play when the racket is in different hitting positions, reflecting the width of the sweet spot and the racket's forgiveness. Using the first surface as the test racket face, the prepared racket was fixed on an angle-adjustable support, maintaining a 60° angle between the racket face and the horizontal plane. A standard peak ball was released freely from a fixed height of 2m above the center of the racket face, dropping towards the center and edge of the racket face 20 times each. The position of the first landing point of the peak ball was recorded, the standard deviation (σ) of the landing point distribution was calculated, and the maximum deviation (Δmax) during the test was recorded. Specific test results are shown in Table 2. Table 2 Results of the accuracy test for rebound landing point

[0045] As can be seen from the test data in Table 2, the standard deviation of the landing point distribution of the embodiment at each test position is significantly smaller than that of the comparative example, especially the maximum deviation is significantly reduced. This indicates that the modified EP-CF racket face of the present invention has excellent stress dispersion ability, which can effectively suppress the problem of uneven rebound force interference that may be generated by the single side of the racket face with the convex structure, and greatly improve the ball release stability in the unconventional hitting area.

[0046] Ten experienced players (DUPR level 4.0 and above) with peak ball experience were invited to conduct 30 minutes of standardized hitting practice (including standard movements such as forehand baseline drive, backhand push, net volley, and drop shot) using both the comparative racket and the racket of this invention. Players rated the racket feel on a scale of 1 to 5 based on the following dimensions, and the average value was calculated: (1) clarity of hitting feedback; (2) shock absorption comfort (wrist and forearm fatigue); (3) spin control; (4) consistency of feedback at different hitting positions; (5) overall hitting satisfaction. The specific scoring results are shown in Table 3. Table 3. Results of the feel rating

[0047] As can be seen from the test results in Table 3, the players rated the racket prepared in this embodiment higher than that of the comparative embodiment. The players generally reported that the racket of this invention has better clarity and accuracy of ball feedback after continuous use.

[0048] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0049] The above description is merely an example and illustration of the concept of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the concept of the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A Peak racket with different elastic coefficients on both sides, characterized in that, include: handle; The inner core layer is connected to the handle; A first surface layer is disposed on one side of the inner core layer; The second surface layer is disposed on the other side of the inner core layer and is disposed opposite to the first surface layer; Both the first and second surface layers are made of modified EP-CF material; The elastic coefficients of the first surface layer and the second surface layer are different. The elastic coefficient of the first surface layer is 0.4-0.55, and the elastic coefficient of the second surface layer is 0.3-0.

45.

2. The Peak racket according to claim 1, characterized in that, One side of the inner core layer has a protrusion structure, while the other side of the inner core layer does not have a protrusion structure.

3. The Peak racket according to claim 1, characterized in that, The first surface layer and the second surface layer each contain different color masterbatch materials, and thus the first surface layer and the second surface layer exhibit different colors.

4. The Peak racket according to claim 1, characterized in that, The modified EP-CF material is formed by hot pressing a modified epoxy adhesive with carbon fiber woven fabric; the modified epoxy adhesive consists of: 10-15wt% modifier, 8-12wt% diluent, 4.5-6.2wt% curing agent, 0.6-0.8wt% defoamer, 0.3-0.4wt% leveling agent, and 0.5-0.7wt% pigment, with the balance being epoxy resin.

5. The Peak racket according to claim 4, characterized in that, The preparation method of the modifier is as follows: Step A1: Mix diaza-18-crown ether-6, bromoalkanol and tetrahydrofuran, then add triethylamine as an acid-binding agent, purge with nitrogen for protection, heat to 65±2℃ and reflux for 12-18h, and obtain the intermediate after treatment; Step A2: Mix the intermediate, tetrabutylammonium bromide and dimethylacetamide, heat to 80-95℃, slowly add epichlorohydrin and react for 5-8 hours, then cool down and control the temperature in a water bath at 40-50℃, add sodium hydroxide aqueous solution and continue the reaction for 2.5-3.5 hours, and the modifier is obtained after treatment.

6. A Peak racket with two sides having different elastic coefficients according to claim 5, characterized in that, The molar ratio of diaza-18-crown ether-6 and bromoalkanol is 1:2.1-2.3, and triethylamine is 20-30 wt% of the total amount of both.

7. A Peak racket with two sides having different elastic coefficients according to claim 6, characterized in that, Bromoalkanol is one of 4-bromobutanol and 8-bromooctanol.

8. A Peak racket with two sides having different elastic coefficients according to claim 7, characterized in that, The molar ratio of the intermediate to epichlorohydrin is 1:1.4-1.6, the amount of tetrabutylammonium bromide is 2.2-3.5 wt% of the total amount of the two, the amount of sodium hydroxide is equal to the molar amount of epichlorohydrin, and the mass fraction of its aqueous solution is 30-35 wt%.

9. A Peak racket with two sides having different elastic coefficients according to any one of claims 1-8, characterized in that, The method for manufacturing the Peak racket is as follows: Step B1: Add modifier, diluent, defoamer, leveling agent, pigment, epoxy resin and curing agent in sequence and mix well. After vacuum degassing, the modified epoxy adhesive is obtained. Step B2: Apply epoxy adhesive to the surface of carbon fiber woven fabric, pre-bake and dry it, then cut it to obtain the modified EP-CF racket face; Step B3: The modified EP-CF racket face is attached to the surface of the inner core layer, and then placed in a mold for hot pressing and curing. After the handle is installed, the Peak racket is made.

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