Production process of EPP core material pike racket containing reinforced plate

Abstract

The invention belongs to the technical field of sports equipment, in particular to a production process of an EPP core material Pick racket containing a reinforced plate, which comprises the following steps: the reinforced plate is a carbon fiber plate or a glass fiber plate; treating the carbon fiber plate or the glass fiber plate; placing the reinforced plate in the center of a mold, putting the EPP raw material into a foaming mold, foaming to enable the EPP raw material to surround the reinforced plate, and embedding the reinforced plate into the EPP core material after EPP foaming; bonding a non-woven fabric layer; and a surface layer is adhered to the outer side of the non-woven fabric layer The purposes that the overall rigidity of the racket is enhanced, deformation of the racket in the ball hitting process is reduced, the ball hitting precision and the strength transmission efficiency are improved, and the service life of the racket is prolonged are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of sports equipment, and specifically relates to a production process of a Pickleball racket with an EPP core material containing a reinforcing plate. Background Art

[0002] In recent years, Pickleball rackets with EPP as the core material have received some attention in the market due to their good elasticity. However, the EPP material itself has the problem of insufficient rigidity and is prone to deformation when impacted by hitting the ball. At the same time, the relatively thin outer surface layer cannot effectively limit this deformation, resulting in a large deformation of the overall racket, affecting the accuracy of hitting the ball and the power transmission, and reducing the use experience of players. In addition, frequent deformation may also accelerate the wear of various components of the racket and shorten the service life. Therefore, it is urgent to improve the structure of the existing EPP core material Pickleball racket to enhance its performance and durability. Summary of the Invention

[0003] The present invention provides a production process of a Pickleball racket with an EPP core material containing a reinforcing plate, aiming to enhance the overall rigidity of the racket, reduce the deformation of the racket during the hitting process, improve the accuracy of hitting the ball and the power transmission efficiency, and extend the service life of the racket.

[0004] A production process of a Pickleball racket with an EPP core material containing a reinforcing plate comprises the following steps:

[0005] S1: The reinforcing plate is a carbon fiber plate or a glass fiber plate; the carbon fiber plate or the glass fiber plate is processed;

[0006] S2: Place the reinforcing plate at the central position of the mold, put the EPP raw material into the foaming mold, heat and melt it to 180 - 220 °C to make the raw materials fully mixed and evenly form a homogeneous system; inject a foaming agent under a pressure of 8 - 12 MPa, quickly reduce the pressure for foaming, control the foaming ratio at 10 - 20 times, so that the EPP raw material surrounds the reinforcing plate, and the reinforcing plate is embedded in the EPP core material after the EPP is foamed;

[0007] S3: After coating an adhesive on both sides of the EPP core material, cover it with a non-woven fabric, and roll and compound it through a rolling equipment, with a rolling pressure of 1.5 - 2.5 MPa to bond the non-woven fabric layer;

[0008] S4: Bond a surface layer outside the non-woven fabric layer; the surface layer is a carbon fiber layer and a glass fiber layer, a carbon fiber layer or a glass fiber layer. When the surface layer is a carbon fiber layer and a glass fiber layer, the carbon fiber layer is the outer layer; after pre-impregnating the glass fiber base fabric and the carbon fiber base fabric with epoxy resin respectively, hot press them at 160 - 180 °C and a pressure of 3 - 5 MPa for 1.5 - 2.5 h to form the surface layer; the total thickness after molding by both of them is 0.1 - 0.5 mm, and the glass fiber layer accounts for 50% - 60% of the total mass of the surface layer;

[0009] Coat the binder on the glass fiber base fabric, and laminate the surface layer onto the non-woven fabric layer through a cold pressing device. The cold pressing pressure is 2 - 3 MPa, and the time is 4 - 6 h to firmly bond the surface layer.

[0010] Preferably, the reinforcing plate is a carbon fiber plate. Cut the carbon fiber prepreg and hot press it into shape in a hot press. The hot pressing temperature is 180 - 200 °C, the pressure is 3 - 5 MPa, and the pressure holding time is 30 - 60 min to make a carbon fiber plate with a thickness of 0.5 - 1.5 mm.

[0011] Preferably, when impregnating the carbon fiber, 3% of the total weight of the carbon fiber prepreg is added with carbon nanotubes for modification.

[0012] Preferably, the reinforcing plate is a glass fiber plate. Immerse the glass fiber cloth in the resin, take it out and cut it after being fully wetted. In the hot press, the hot pressing temperature is 150 - 170 °C, the pressure is 2 - 4 MPa, and hot press for 40 - 80 min to make a glass fiber plate with a thickness of 1 - 2 mm.

[0013] Preferably, 5% of the total weight of the resin is added with nano-silica particles during the process of impregnating the glass fiber cloth with the resin.

[0014] Preferably, the non-woven fabric layer is bonded to both sides of the EPP core material through a two-component polyurethane binder with a coating amount of 80 - 100 g / m².

[0015] Preferably, in the surface layer, the carbon fiber layer is an epoxy carbon fiber prepreg molded sheet with a thickness of 0.1 - 0.5 mm.

[0016] Preferably, in the surface layer, the glass fiber layer is an epoxy glass fiber semi-cured sheet with a thickness of 0.1 - 0.5 mm.

[0017] Preferably, the binder coated on the glass fiber base fabric is a two-component polyurethane binder with a coating amount of 100 - 120 g / m 2 。

[0018] Preferably, trim the edges of the composite racket board, polish the surface, and perform appearance decoration.

[0019] In the present invention, the reinforcing plate and the EPP core material together constitute the core support structure of the racket, and in combination with the surface layer composed of a carbon fiber layer and a glass fiber layer, a carbon fiber layer or a glass fiber layer, the following beneficial effects are achieved:

[0020] 1. Improve the rigidity and stability of the Peak racket: The addition of the carbon fiber plate or the glass fiber plate significantly enhances the rigidity of the EPP core material, effectively reduces the deformation of the racket during hitting, makes the hitting more accurate, the power transmission more stable and efficient, and improves the hitting experience and competitive level of the player.

[0021] 2. Prolong the service life of the Pickleball racket: Reduce the risk of material fatigue and damage caused by long-term stress deformation, reduce the deformation of the EPP core material, extend the service life of the racket, reduce the frequency of racket replacement, and save costs for players.

[0022] 3. Optimize performance balance: While enhancing rigidity, by reasonably designing the thickness and performance of each layer of material, maintain the light weight and elasticity of the racket, ensure that the racket is not affected in terms of controllability and hitting feel, and achieve an optimized balance of performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a multi-layer structure diagram of the EPP core material Pickleball racket of the present invention;

[0024] Figure 2 It is a schematic structural diagram of the EPP core material Pickleball racket of the present invention;

[0025] Figure 3 is Figure 2 The enlarged view of the middle part in the circle;

[0026] In the figure: 1. Reinforcing plate; 2. EPP core material; 3. Non-woven fabric layer; 4. Surface layer; 5. Glass fiber layer; 6. Carbon fiber layer. DETAILED DESCRIPTION OF THE INVENTION

[0027] The technical solution of the present invention will be further explained and illustrated below through specific embodiments.

[0028] Example 1

[0029] The present invention provides a production process for an EPP core material Pickleball racket containing a reinforcing plate, and the steps are as follows:

[0030] S1: Heat press the cut carbon fiber prepreg in a hot press, with a hot press temperature of 180 °C, a pressure of 3 MPa, and a pressure holding time of 30 min, to make a carbon fiber plate with a thickness of 0.8 mm as the reinforcing plate;

[0031] S2: Place the carbon fiber plate at the center position of the mold, put the PP resin with a melt strength of 35 - 45 MPa, add 0.8% - 1.2% of calcium carbonate nucleating agent and 0.4% - 0.6% of stabilizer based on the weight of the resin into the foaming mold, heat and melt it to 190 °C to make the raw materials fully mixed and evenly form a homogeneous system; inject 1.5% - 2.5% of carbon dioxide as the foaming agent under a pressure of 11 MPa, quickly reduce the pressure for foaming, control the foaming ratio at 18 times, so that the EPP raw material surrounds the reinforcing plate, and the carbon fiber plate is embedded in the EPP core material after EPP foaming; obtain an EPP core material with a density of 55 kg / m 3 and a compressive strength of 1.7 MPa;

[0032] S3: Coat both sides of the EPP core material with a two-component polyurethane binder (the ratio of the main agent to the curing agent is 5:1), and the coating amount is 80 g / m 2 , cover it with non-woven fabric, and roll and compound it through a rolling equipment. The rolling pressure is 1.5 MPa to bond the non-woven fabric layer; ensure a tight fit without air bubbles or wrinkles. In this embodiment, the non-woven fabric layer uses high-strength PET non-woven fabric. The PET non-woven fabric has a large tensile strength and a strong adhesive force with the EPP core material. When in a tension state, it can improve the bending and compressive strength of the overall structure, prevent delamination, and ensure the integrity of the racket structure;

[0033] S4: Bond the surface layer on the outside of the non-woven fabric layer; the surface layer includes a carbon fiber layer and a glass fiber layer, and the carbon fiber layer is the outer layer; in the surface layer, the carbon fiber layer uses an epoxy carbon fiber prepreg molding sheet with a thickness of 0.2 mm to provide sufficient hardness and compressive strength for the racket surface and stabilize the hitting process; the glass fiber layer selects an epoxy glass semi-cured sheet with a thickness of 0.2 mm. Enhance the adhesion between the surface layer and the non-woven fabric layer and improve the overall elasticity of the racket, making it easier to hit the ball.

[0034] After pre-impregnating the glass fiber base fabric and the carbon fiber base fabric with epoxy resin respectively, hot-press them at 160 °C and a pressure of 3 MPa for 1.5 h to form the surface layer; the total thickness after molding is 0.4 mm, and the glass fiber layer accounts for 60% of the total mass of the surface layer;

[0035] Coat the glass fiber base fabric with a two-component polyurethane binder, and the coating amount is 100 g / m 2 , and compound the surface layer to the non-woven fabric layer through a cold-press equipment. The cold-press pressure is 2 MPa and the time is 4 h to firmly bond the surface layer;

[0036] S5: Trim the edges of the composite racket board, use a numerical control cutting equipment to remove the excess parts to make the edges neat and smooth; then perform surface grinding and polishing treatments to improve the surface finish and texture; finally, perform appearance decoration, such as printing brand logos, patterns, etc. to complete the production of the racket.

[0037] Test the racket of this embodiment. The rigidity of the sweet spot is increased by 40%, the hitting accuracy is improved by 25%. After hitting the ball continuously 1500 times, the overall racket has no obvious deformation and there is no delamination between layers.

[0038] Example 2

[0039] The present invention provides a production process for a Peak racket with an EPP core material containing a reinforcing plate, and the steps are as follows:

[0040] S1: Prepare a reinforced plate, which is a fiberglass plate. The fiberglass cloth is impregnated in resin, taken out and cut after being fully soaked, and hot-pressed in a hot press at a hot-pressing temperature of 150 °C and a pressure of 2 MPa for 40 minutes to make a fiberglass plate with a thickness of 1.2 mm.

[0041] S2: Place the fiberglass plate at the center of the mold. Put PP resin with a melt strength of 30 - 40 MPa, 0.5% - 1% talc nucleating agent based on the resin weight, and 0.3% - 0.5% stabilizer into the foaming mold, heat and melt it to 200 °C to make the raw materials fully mixed and evenly form a homogeneous system; inject 1% - 2% azodicarbonamide as a foaming agent under a pressure of 10 MPa, quickly reduce the pressure for foaming, and control the foaming ratio at 15 times, so that the EPP raw material surrounds the reinforced plate. After the EPP is foamed, the fiberglass plate is embedded in the EPP core material; obtain 50 kg / m of EPP core material 3 with a compression strength of 1.6 MPa.

[0042] S3: Coat both sides of the EPP core material with a two-component polyurethane binder (the ratio of the main agent to the curing agent is 5:1), and the coating amount is 100 g / m 2 , cover with non-woven fabric, and roll and compound through a rolling equipment with a rolling pressure of 2.5 MPa to bond the non-woven fabric layer; ensure a tight fit without air bubbles and wrinkles. In this embodiment, the non-woven fabric layer uses a high-strength PET non-woven fabric. The PET non-woven fabric has a large tensile strength and a strong adhesion to the EPP core material. When in a tension state, it can improve the bending and compressive strength of the overall structure, prevent delamination, and ensure the integrity of the racket structure.

[0043] S4: Bond the surface layer on the outside of the non-woven fabric layer; the surface layer includes a carbon fiber layer and a glass fiber layer. In the surface layer, the carbon fiber layer uses an epoxy carbon fiber prepreg molding sheet with a thickness of 0.3 mm to provide sufficient hardness and compressive strength for the racket surface and stabilize the hitting process; the glass fiber layer selects an epoxy glass semi-cured sheet with a thickness of 0.2 mm. It enhances the adhesion between the surface layer and the non-woven fabric layer and improves the overall elasticity of the racket, making it easier to hit the ball.

[0044] After the fiberglass base cloth and the carbon fiber base cloth are respectively pre-impregnated with epoxy resin, they are hot-pressed at 180 °C and a pressure of 5 MPa for 2.5 h to form the surface layer; the carbon fiber layer is the outer layer; the total thickness after molding is 0.5 mm, and the glass fiber layer accounts for 55% of the total mass of the surface layer.

[0045] Coat the fiberglass base cloth with a two-component polyurethane binder, and the coating amount is 120 g / m 2 , and compound the surface layer to the non-woven fabric layer through a cold pressing equipment with a cold pressing pressure of 3 MPa and a time of 6 h to firmly bond the surface layer.

[0046] S5: Trim the edges of the composite racket board. Use numerical control cutting equipment to remove the excess parts to make the edges neat and smooth. Then, perform surface grinding and polishing to improve the surface finish and texture. Finally, perform appearance decoration, such as printing brand logos, patterns, etc., to complete the production of the racket.

[0047] Test the racket of this embodiment. The rigidity of the sweet spot is increased by 35%, and the power transmission efficiency is increased by 22%. After hitting the ball continuously 1200 times, the performance of the racket is stable and there is no obvious damage.

[0048] Embodiment 3

[0049] The present invention provides a production process for a Peak racket with an EPP core material containing a reinforced board, and the steps are as follows:

[0050] S1: Thermally press the cut carbon fiber prepreg in a hot press. The hot press temperature is 200 °C, the pressure is 5 MPa, and the pressure holding time is 60 min to make a carbon fiber board with a thickness of 1.5 mm as the reinforced board.

[0051] S2: Place the carbon fiber board at the center position of the mold. Put PP resin with a melt strength of 40 - 50 MPa, 1% - 1.5% by weight of talc nucleating agent and 0.5% - 0.7% of stabilizer based on the resin weight into the foaming mold, heat and melt it to 210 °C to fully mix the raw materials evenly to form a homogeneous system. Inject 2% - 3% of azodicarbonamide as the foaming agent under a pressure of 8 MPa, and quickly reduce the pressure for foaming. Control the foaming ratio at 12 times, so that the EPP raw material surrounds the reinforced board. After EPP foaming, the carbon fiber board is embedded in the EPP core material. The density of the obtained EPP core material is 45 kg / m 3 , and the compression strength is 1.5 MPa;

[0052] S3: Coat a two-component polyurethane binder (the ratio of the main agent to the curing agent is 5:1) on both sides of the EPP core material. The coating amount is 90 g / m 2 , cover with non-woven fabric, and roll and composite through a rolling equipment. The rolling pressure is 2 MPa to bond the non-woven fabric layer. Ensure that the fit is tight without air bubbles and wrinkles. In this embodiment, the non-woven fabric layer uses high-strength PET non-woven fabric. The PET non-woven fabric has a large tensile strength and a strong adhesion to the EPP core material. When in a tension state, it can improve the bending and compressive strength of the overall structure, prevent delamination, and ensure the integrity of the racket structure;

[0053] S4: Bond the surface layer on the outside of the non-woven fabric layer; the surface layer includes a carbon fiber layer and a glass fiber layer. In the surface layer, the carbon fiber layer uses an epoxy carbon fiber prepreg molding sheet with a thickness of 0.4 mm to provide sufficient hardness and compressive strength for the racket surface and stabilize the hitting process; the glass fiber layer selects an epoxy glass fiber semi-cured sheet with a thickness of 0.1 mm. Enhance the adhesion between the surface layer and the non-woven fabric layer and improve the overall elasticity of the racket to make hitting the ball more labor-saving.

[0054] After pre - impregnating the glass fiber base fabric and the carbon fiber base fabric with epoxy resin respectively, they are hot - pressed at 170 °C and 4 MPa for 2.0 h to form the surface layer; the carbon fiber layer is the outer layer; the total thickness after molding by die - pressing is 0.5 mm, and the glass fiber layer accounts for 50% of the total mass of the surface layer;

[0055] The binder coated on the glass fiber base fabric is a two - component polyurethane binder, and the coating amount is 110 g / m 2 , and the surface layer is laminated to the non - woven fabric layer through a cold - pressing device with a cold - pressing pressure of 2.5 MPa and a time of 5 h to firmly bond the surface layer;

[0056] S5: Trim the edges of the composite racket board, use a numerical control cutting device to remove the excess part to make the edges neat and smooth; then perform surface grinding and polishing to improve the surface finish and texture; finally, perform appearance decoration, such as printing brand logos, patterns, etc., to complete the production of the racket.

[0057] The racket of this embodiment is tested. This racket is outstanding in terms of lightweight, with a 50% increase in the rigidity of the sweet spot and a 30% increase in durability, meeting the diverse performance requirements of different players for the racket.

[0058] Example 4

[0059] The present invention provides a production process for a Peak racket with an EPP core material containing a reinforcing plate, and the steps are as follows:

[0060] S1: Prepare the reinforcing plate. The reinforcing plate is a glass fiber plate, which is impregnated in resin by glass fiber cloth, and 5% of the total weight of the resin of nano - silica particles is added during the process of impregnating the glass fiber cloth with resin. After being fully infiltrated, it is taken out and cut. In a hot - press, the hot - press temperature is 170 °C, the pressure is 4 MPa, and the hot - press time is 80 min to make a glass fiber plate with a thickness of 1.0 mm; the nano - silica particles can be evenly dispersed in the resin, filling the micro - pores of the glass fiber plate, enhancing the denseness of the internal structure of the glass fiber plate, and improving the strength and rigidity of the glass fiber plate;

[0061] S2: Place the glass fiber plate at the center position of the mold, put PP resin with a melt strength of 42 - 52 MPa, add 1.1% - 1.6% of mica powder as a nucleating agent based on the weight of the resin, and 0.55% - 0.75% of a stabilizer into the foaming mold, heat and melt it to 205 °C to make the raw materials fully mixed and form a homogeneous system; inject 2.2% - 3.2% of the physical foaming agent pentane as a foaming agent under a pressure of 9 MPa, quickly reduce the pressure for foaming, and control the foaming ratio at 14 times, so that the EPP raw material surrounds the reinforcing plate, and the glass fiber plate is embedded in the EPP core material after EPP foaming; obtain an EPP core material of 48 kg / m 3, Compressive strength is 1.55 MPa; Pentane is used as a physical foaming agent, which can make the cell structure of EPP more uniform and fine, and improve the comprehensive performance of the EPP core material;

[0062] S3: Coat the two-component polyurethane binder (the ratio of the main agent to the curing agent is 5:1) on both sides of the EPP core material. The coating amount is 85 g / m 2 , cover with non-woven fabric, and roll and compound through a rolling equipment. The rolling pressure is 2.3 MPa to bond the non-woven fabric layer; ensure a tight fit without air bubbles and wrinkles. In this embodiment, the non-woven fabric layer uses high-strength PET non-woven fabric. The PET non-woven fabric has a large tensile strength and a strong adhesion to the EPP core material. When in a tension state, it can improve the bending and compressive strength of the overall structure, prevent delamination, and ensure the integrity of the racket structure;

[0063] S4: Bond the surface layer on the outside of the non-woven fabric layer; the surface layer includes a carbon fiber layer and a glass fiber layer. In the surface layer, the carbon fiber layer uses an epoxy carbon fiber prepreg molding sheet with a thickness of 0.25 mm to provide sufficient hardness and compressive strength for the racket surface and stabilize the hitting process; the glass fiber layer selects an epoxy glass fiber semi-cured sheet with a thickness of 0.25 mm. Enhance the adhesion between the surface layer and the non-woven fabric layer and improve the overall elasticity of the racket, making it easier to hit the ball.

[0064] After pre-impregnating the glass fiber base cloth and the carbon fiber base cloth with epoxy resin respectively, hot press them at 165 °C and a pressure of 4.5 MPa for 1.8 h to form the surface layer; the carbon fiber layer is the outer layer; the total thickness after molding is 0.5 mm, and the glass fiber layer accounts for 58% of the total mass of the surface layer;

[0065] Coat the two-component polyurethane binder on the glass fiber base cloth. The coating amount is 105 g / m 2 , and compound the surface layer to the non-woven fabric layer through a cold pressing equipment. The cold pressing pressure is 2.2 MPa and the time is 4.5 h to firmly bond the surface layer;

[0066] S5: Trim the edges of the composite racket board, use a numerical control cutting equipment to remove the excess part to make the edges neat and smooth; then perform surface grinding and polishing to improve the surface finish and texture; finally, perform appearance decoration, such as printing brand logos, patterns, etc. to complete the production of the racket.

[0067] Test the racket of this embodiment. The overall rigidity of this racket is increased by 15% compared with the glass fiber board enhanced racket without adding nano-silica. In the actual hitting test, 15 professional players were invited to try it. The feedback shows that the stability and power feedback effect during hitting are good. After hitting the ball 1800 times continuously, only slight wear appears on the racket, and the performance of each component is still good, demonstrating excellent durability.

[0068] Example 5

[0069] The present invention provides a production process for an EPP core pick racket with enhanced plates, and the steps are as follows:

[0070] S1: When pre-impregnating carbon fiber, 3% by weight of carbon nanotubes based on the weight of the carbon fiber pre-impregnating material is added to the carbon fiber pre-impregnating material for modification. Then, the cut carbon fiber pre-impregnating material is hot-pressed and formed in a hot press. The hot-pressing temperature is 190 °C, the pressure is 4 MPa, and the pressure-holding time is 50 min to make a carbon fiber plate with a thickness of 1.3 mm as the enhanced plate; carbon nanotubes have extremely high strength and good electrical conductivity, and can act synergistically with carbon fiber to significantly improve the mechanical properties of the carbon fiber plate.

[0071] S2: Place the carbon fiber plate at the center position of the mold. Put PP resin with a melt strength of 38 - 48 MPa, 0.9% - 1.4% by weight of kaolin as a nucleating agent based on the weight of the resin, and 0.45% - 0.65% of a stabilizer into the foaming mold, heat and melt it to 195 °C to fully mix and homogenize the raw materials to form a homogeneous system; inject 1.8% - 2.8% of diisopropyl azodicarboxylate as a foaming agent under a pressure of 10.5 MPa, quickly reduce the pressure for foaming, and control the foaming ratio at 16 times to make the EPP raw material surround the enhanced plate. After EPP foaming, the carbon fiber plate is embedded in the EPP core; the density of the obtained EPP core is 53 kg / m 3 , and the compressive strength is 1.7 MPa;

[0072] S3: Coat both sides of the EPP core with a two-component polyurethane binder (the ratio of the main agent to the curing agent is 5:1), and the coating amount is 95 g / m 2 , cover it with non-woven fabric, and roll and compound it through a rolling equipment. The rolling pressure is 1.8 MPa to bond the non-woven fabric layer; ensure a tight fit without air bubbles and wrinkles. In this embodiment, the non-woven fabric layer uses high-strength PET non-woven fabric. The PET non-woven fabric has a large tensile strength and a strong adhesion to the EPP core. When in a tension state, it can improve the bending and compressive strength of the overall structure, prevent delamination, and ensure the integrity of the racket structure;

[0073] S4: Bond the surface layer on the outside of the non-woven fabric layer; the surface layer includes a carbon fiber layer and a glass fiber layer. In the surface layer, the carbon fiber layer uses an epoxy carbon fiber pre-impregnated molding sheet with a thickness of 0.35 mm to provide sufficient hardness and compressive strength for the racket surface and stabilize the hitting process; the glass fiber layer uses an epoxy glass fiber semi-cured sheet with a thickness of 0.15 mm. It enhances the adhesion between the surface layer and the non-woven fabric layer and improves the overall elasticity of the racket, making it easier to hit the ball.

[0074] After pre-impregnating the glass fiber base fabric and the carbon fiber base fabric with epoxy resin respectively, hot-press them at 175 °C and a pressure of 3.5 MPa for 2.2 h to form the surface layer; the carbon fiber layer is the outer layer; the total thickness after molding by pressing is 0.5 mm, and the glass fiber layer accounts for 53% of the total mass of the surface layer;

[0075] The binder coated on the fiberglass base fabric is a two-component polyurethane binder, and the coating amount is 115 g / m 2 , and the surface layer is laminated to the non-woven fabric layer through a cold pressing device. The cold pressing pressure is 2.8 MPa and the time is 5.5 h, so that the surface layer is firmly bonded;

[0076] S5: Trim the edges of the composite racket board, use a numerical control cutting device to remove the excess part to make the edges neat and smooth; then perform surface grinding and polishing to improve the surface finish and texture; finally, perform appearance decoration, such as printing brand logos, patterns, etc., to complete the production of the racket.

[0077] The racket of this embodiment is tested, and the rigidity of the sweet spot of the racket is increased by 55%. In the durability test simulating different environments, whether in high temperature and high humidity or low temperature and dry environments, after hitting the ball 2000 times continuously, the structural integrity and performance of the racket remain good, proving the excellent performance of the carbon nanotube modified carbon fiber board combined with the EPP core material, as well as the adaptability to different use environments.

[0078] Comparative test

[0079] To fully verify the effectiveness of adding carbon fiber boards or fiberglass boards in the present invention in improving the performance of EPP core material Pickleball rackets, a series of comparative tests were carried out.

[0080] Rigidity comparison: Select a common EPP core material Pickleball racket without adding reinforcement plates as the control group, and compare the rigidity with the racket with a fiberglass board added in Example 2. Use an electronic universal testing machine to apply the same pressure load to the sweet spot of the racket, and record the deformation of the racket. The results show that when the pressure of the control group racket reaches 60 N, the deformation of the sweet spot reaches 4 mm; while for the racket with a fiberglass board added, the deformation is only 1.5 mm under the same pressure, indicating that adding a fiberglass board can significantly improve the rigidity of the racket.

[0081] Hitting performance comparison: Invite 20 amateur players with comparable levels to practice hitting the ball using the control group racket and the racket with a carbon fiber board added in Example 3 respectively. Count the number of times the players hit the target area within a specified time to evaluate the hitting accuracy. The results show that the hitting accuracy of the players using the racket with a carbon fiber board added has increased by an average of 30%. At the same time, by analyzing the ball speed and flight trajectory at the moment of hitting the ball through a high-speed camera, it is found that the racket with a carbon fiber board added can increase the ball speed by an average of 10%, and the power transmission is more efficient, significantly improving the hitting performance.

[0082] Durability comparison: Simulate the high-intensity game usage scenario, and conduct continuous hitting tests on the control group racket and the racket with the nano-silica modified glass fiber board added in Example 4. Check the damage of the racket every 200 hits, and record the number of hits when obvious deformation, delamination and other failure phenomena occur. The results show that obvious deformation in the sweet spot and local delamination occur in the control group racket after about 1000 hits; while the racket with the nano-silica modified glass fiber board added can still maintain good performance and structural integrity after 2500 continuous hits, fully proving that adding the enhanced board can greatly extend the service life of the racket.

[0083] Through the above detailed specific implementation methods and comparative tests, it is fully demonstrated that the present invention has a significant effect on improving the performance and durability of the Peak racket by adding a carbon fiber board or a glass fiber board to the EPP core material, and has outstanding technical advantages and practical application value.

Claims

1. A production process of an EPP core material badminton racket with enhanced plates, characterized in that, The steps are as follows: S1: The reinforcing plate is a carbon fiber plate or a glass fiber plate; the carbon fiber plate or the glass fiber plate is processed; S2: Place the reinforcing plate at the center position of the mold, put the EPP raw material into the foaming mold, heat and melt it to 180 - 220 °C to make the raw materials fully mixed and evenly form a homogeneous system; inject the foaming agent under a pressure of 8 - 12 MPa, quickly reduce the pressure for foaming, control the foaming ratio at 10 - 20 times, so that the EPP raw material surrounds the reinforcing plate, and the reinforcing plate is embedded in the EPP core material after EPP foaming; S3: After coating the adhesive on both sides of the EPP core material, cover it with non-woven fabric, and roll and compound it through a rolling equipment, with a rolling pressure of 1.5 - 2.5 MPa to bond the non-woven fabric layer; S4: Bond the surface layer on the outside of the non-woven fabric layer; the surface layer is a carbon fiber layer and a glass fiber layer, a carbon fiber layer or a glass fiber layer. When the surface layer is a carbon fiber layer and a glass fiber layer, the carbon fiber layer is the outer layer; after pre-impregnating the glass fiber base cloth and the carbon fiber base cloth with epoxy resin respectively, hot press them at 160 - 180 °C and a pressure of 3 - 5 MPa for 1.5 - 2.5 h to form the surface layer; the total thickness after molding by die pressing is 0.1 - 0.5 mm, and the glass fiber layer accounts for 50% - 60% of the total mass of the surface layer; Coat the adhesive on the glass fiber base cloth, and compound the surface layer to the non-woven fabric layer through a cold pressing equipment, with a cold pressing pressure of 2 - 3 MPa and a time of 4 - 6 h to firmly bond the surface layer.

2. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that, The reinforcing plate is a carbon fiber plate, and the cut carbon fiber prepreg is hot pressed and formed in a hot press, with a hot pressing temperature of 180 - 200 °C, a pressure of 3 - 5 MPa, and a holding pressure time of 30 - 60 min to make a carbon fiber plate with a thickness of 0.5 - 1.5 mm.

3. The production process of an EPP core pick racket with enhanced plates according to claim 2, characterized in that, When the carbon fiber is pre-impregnated, 3% of the total weight of the carbon fiber prepreg is added with carbon nanotubes for modification.

4. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that, The reinforcing plate is a glass fiber plate, which is impregnated in resin by glass fiber cloth, taken out and cut after being fully infiltrated, and in a hot press, the hot pressing temperature is 150 - 170 °C, the pressure is 2 - 4 MPa, and hot press for 40 - 80 min to make a glass fiber plate with a thickness of 1 - 2 mm.

5. The production process of an EPP core pick racket with enhanced plates according to claim 4, characterized in that, 5% of the total weight of the resin is added with nano-silica particles during the process of impregnating the glass fiber cloth with resin.

6. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that, The non-woven fabric layer is bonded to both sides of the EPP core material by a two-component polyurethane binder with a coating amount of 80 - 100 g / m 2 .

7. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that, In the surface layer, the carbon fiber layer is a molded sheet of epoxy carbon fiber prepreg with a thickness of 0.1 - 0.5 mm.

8. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that In the surface layer, the glass fiber layer is a semi-cured sheet of epoxy glass fiber with a thickness of 0.1 - 0.5 mm.

9. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that, The binder coated on the fiberglass base fabric is a two-component polyurethane binder, and the coating amount is 100-120 g / m 2 .

10. The production process of an EPP core pick racket with enhanced plates according to claim 1, characterized in that, Trim the edges of the composite racket plate, polish the surface, and perform appearance decoration.

Images