EPP board and application thereof

Abstract

The invention relates to the technical field of materials, and particularly belongs to an EPP board and application thereof. The EPP board comprises the following raw material components: EPP particles, a foaming agent, a nucleating agent and a stabilizer. Meanwhile, the invention further provides application of the EPP board to the Pick racket. Through a reasonable production process and a production process added with chopped fibers, the produced EPP board is suitable for the use of a Pick racket.

Description

Technical Field

[0001] The present invention relates to the technical field of materials, and specifically belongs to an EPP board and its application. Background Art

[0002] EPP (expanded polypropylene) has been used as a raw material in the production of pick rackets. However, the existing EPP is mainly used for other raw materials and is not developed according to the characteristics of pick rackets. When using a pick racket, appropriate elasticity, strength, and service life are required to ensure stability during hitting and reduce fatigue after use. Therefore, how to combine the characteristics of EPP with those of pick rackets to optimize the shape, weight distribution, hitting performance, and comfort of the racket remains a technical challenge. Summary of the Invention

[0003] The present invention provides an EPP board suitable for use in pick rackets to achieve the purpose of improving the elasticity, strength, and durability of the racket.

[0004] Meanwhile, the present invention also provides the application of the EPP board in pick rackets.

[0005] An EPP board, the raw material components of which include EPP particles, a foaming agent, a nucleating agent, and a stabilizer.

[0006] Preferably, the production steps of the EPP board are as follows:

[0007] S11: After uniformly mixing the EPP particles, the nucleating agent, and the stabilizer, put them into a foaming device, heat and melt them to 180 - 220 °C to make the materials mix uniformly to form a homogeneous system; then inject the foaming agent under a pressure of 8 - 12 MPa, quickly reduce the pressure for foaming, and control the foaming ratio to 10 - 20 times;

[0008] S12: Cool and shape the EPP blank, and cool it naturally or by forced air cooling to room temperature.

[0009] Preferably, short cut fibers are further added to the raw material components of the EPP board; the length of the short cut fibers is between 5 - 15 mm, and the addition amount of the fibers is 5% - 30% of the total weight of the EPP;

[0010] The production steps of the EPP board added with short cut fibers are as follows:

[0011] S21: First, dry the EPP particles to remove the moisture in the EPP particles; uniformly mix the EPP particles and the short cut fibers;

[0012] S22: Foaming, with the foaming process temperature being 110°C - 130°C; the pressure being 0.8 MPa - 1.2 MPa; the foaming time being 30 min - 2 h; controlling the foaming density to be 30 - 70 kg / m 3 ;

[0013] S23: After foaming is completed, cool and shape the EPP foam material.

[0014] Preferably, the short-cut fibers are one or a combination of carbon fibers, glass fibers, or aramid fibers.

[0015] Preferably, when the short-cut fibers are carbon fibers or glass fibers, the fiber length is 5 - 10 mm.

[0016] Preferably, when the short-cut fibers are aramid fibers, the addition amount is 5% - 20% of the total weight of EPP.

[0017] Preferably, for the Peak badminton racket containing the above EPP board, the production steps are as follows:

[0018] Step 11: Uniformly coat the adhesive on both sides of the cut EPP core material, then cover with non-woven fabric and roll and compound through a rolling equipment, with the rolling pressure being 1.5 - 2.5 MPa;

[0019] Step 12: After pre-impregnating the glass fiber base cloth and carbon fiber base cloth with epoxy resin respectively, hot press at 160 - 180°C and 3 - 5 MPa pressure for 1.5 - 2.5 h to form the surface layer; when the surface layer is a glass fiber base cloth and a carbon fiber base cloth, coat the adhesive on one side of the glass fiber base cloth, and then compound the surface layer to the non-woven fabric layer through a cold press equipment, with the cold press pressure being 2 - 3 MPa and the time being 4 - 6 h.

[0020] Preferably, for the Peak badminton racket containing the above EPP board, the production steps are as follows:

[0021] Step 21: Cross-ply the fiber cloth five layers in the 90° and 0° directions as the surface layer;

[0022] Step 22: For the EPP board core after grinding and corona treatment, paste the surface layer on both sides with epoxy resin adhesive;

[0023] Step 23: Set the molding temperature, pressure, and holding time on the molding press. After reaching the temperature, put the semi-finished product obtained in Step 22 into a fixed mold for high-temperature molding;

[0024] Step 24: Demold the molded badminton racket. After demolding, clean the resin on the edge of the badminton racket, and grind the burrs and carbon edges on the edge of the badminton racket flat in the 45° direction;

[0025] Step 25: Clean the surface, wipe the surface of the badminton racket clean with degreasing oil, and there is no residual lint on the edge;

[0026] Step 26: Install a handle gasket on the racket and reinforce it with pneumatic nails.

[0027] Step 27: Install the back cover and also fix it with pneumatic nails.

[0028] Step 28: Install a PU edge strip to protect the racket frame.

[0029] Step 29: Wind the handle leather and install the rubber roll.

[0030] Advantages of the present invention:

[0031] In this application, through a reasonable production process and a production process with chopped fibers added, the EPP board produced is suitable for use in a Peak racket; through the strengthening treatment of chopped fibers, the resilience, strength, and rigidity of the core material are further improved: after being strengthened by chopped fibers, the racket can effectively rebound during the hitting process, improving the controllability of hitting; it also reduces damage caused by powerful hitting or high-frequency use; adding chopped fibers also enhances the durability of the racket: after adding fibers, the tensile strength and wear resistance of the core material are enhanced, and the racket has a longer service life. Improve strength

[0032] The EPP board produced through the production process of this application is applied in a Peak racket. The EPP board core is combined with the surface layer composed of non-woven fabric, fiberglass base fabric, and carbon fiber base fabric, improving the elasticity, strength, and comfort of the racket; in another preparation method, the EPP board core is combined with multiple layers of carbon fiber through epoxy resin glue and is tightly integrated into one body using a high-temperature forming process. In this process, the epoxy resin plays a good bonding role, ensuring a stable connection between the EPP board core and the carbon fiber;

[0033] 1. The use of multiple layers of carbon fiber not only enhances the overall strength of the racket, enabling it to withstand greater hitting forces, but also endows the racket with better flexibility, helping to improve the feel and control accuracy when hitting the ball.

[0034] 2. The EPP board core is located at the core position of the racket structure, giving full play to its high elasticity and buffering performance, and further optimizing the hitting performance of the racket.

[0035] 3. The structure reinforced by multiple layers of carbon fiber ensures the stability of the racket during the hitting process, avoiding deformation caused by uneven stress, thereby improving the accuracy of hitting and the transmission efficiency of power.

[0036] 4. In terms of control accuracy, the optimized structural design of the racket and the characteristics of carbon fiber enable athletes to more precisely control the hitting direction and strength.

[0037] 5. The excellent buffering performance of the EPP board core can effectively reduce the impact force on the wrist and arm during hitting, reduce the risk of athlete injury, and improve the comfort of use. Description of the Drawings

[0038] Figure 1 It is a schematic structural diagram of the EPP unidirectionally bonded carbon fiber cloth in Example 8 of the present invention;

[0039] In the figure: 1. EPP board core; 2. 90° laid fiber cloth; 3. 0° laid fiber cloth. Detailed Embodiments

[0040] The technical solution of the present invention will be further explained and illustrated below through specific embodiments.

[0041] Example 1

[0042] An EPP board, the raw material components include PP resin with a melt strength of 30 - 40 MPa as the raw material, adding 1% - 2% of AC blowing agent, 0.5% - 1% of talc nucleating agent and 0.3% - 0.5% of stabilizer based on the weight of the resin.

[0043] The production steps of the EPP board are as follows:

[0044] S11: After mixing the EPP particles, nucleating agent and stabilizer evenly, put them into the foaming equipment, heat and melt to 200 °C to make the materials mix evenly to form a homogeneous system; then inject the blowing agent under a pressure of 10 MPa, quickly reduce the pressure for foaming, and control the foaming ratio to 15 times;

[0045] S12: Cool and shape the EPP blank, and naturally cool it to room temperature; obtain an EPP core material with a density of 50 kg / m 3 and a compressive strength of 1.6 MPa.

[0046] Example 2

[0047] A Peak badminton racket containing the EPP board in Example 1, the production steps are as follows:

[0048] Step 11: Evenly coat the two sides of the cut EPP core material with a two-component polyurethane binder, and the coating amount is 90 g / m 2 ; then cover the PET non-woven fabric and roll and compound it through a rolling equipment, and the rolling pressure is 1.5 - 2.5 MPa to ensure tight fitting without air bubbles and wrinkles.

[0049] Step 12: 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 a surface layer. Coat a two-component polyurethane binder on one side of the surface layer of the glass fiber base cloth, and the coating amount is 110 g / m 2, and then the surface layer is laminated onto the non-woven fabric layer by a cold pressing device with a cold pressing pressure of 2 - 3 MPa and a time of 4 - 6 h to ensure a firm bond.

[0050] In the surface layer, the carbon fiber layer uses a 0.3 mm thick epoxy carbon fiber prepreg molded sheet, and the glass fiber layer uses a 0.2 mm thick epoxy glass fiber semi-cured sheet. After molding, the surface layer is 0.5 mm thick, and the glass fiber layer accounts for 55% of the total mass of the surface layer.

[0051] The racket of this embodiment is tested. After 1000 times of hitting tests, the EPP core material has no obvious deformation, the sweet spot is flat, there is no delamination, the hitting performance is stable, the elasticity and power feedback are good, and the satisfaction effect is better.

[0052] The surface layer can also be a single glass fiber layer or carbon fiber layer.

[0053] Example 3

[0054] An EPP board, the raw material components include PP resin with a melt strength of 35 - 45 MPa as the raw material, adding 1.5% - 2.5% of the resin weight of CO2 foaming agent, 0.8% - 1.2% of calcium carbonate nucleating agent and 0.4% - 0.6% of stabilizer.

[0055] The production steps of the described EPP board are as follows:

[0056] S11: After mixing the EPP particles, nucleating agent and stabilizer evenly, put them into a foaming device, heat and melt to 190 °C to make the materials mix evenly to form a homogeneous system; then inject the foaming agent under a pressure of 11 MPa, quickly reduce the pressure to foam, and control the foaming ratio to 18 times;

[0057] S12: The EPP blank is cooled and shaped, and forced air-cooled to room temperature; an EPP core material with a density of 55 kg / m 3 and a compressive strength of 1.7 MPa is obtained.

[0058] And a Peak racket is produced by the process flow of Example 2. Among them, both the carbon fiber layer and the glass fiber layer in the surface layer are 0.2 mm thick, and after molding, the surface layer is 0.4 mm thick, and the glass fiber layer accounts for 60% of the total mass of the surface layer.

[0059] After testing, the racket has better rigidity and elastic recovery under the same hitting conditions, and the performance is good after 1200 times of hitting.

[0060] Example 4

[0061] An EPP board, the raw material components include PP resin with a melt strength of 40 - 50 MPa as the raw material, adding 2% - 3% of the resin weight of AC foaming agent, 1% - 1.5% of talcum powder nucleating agent and 0.5% - 0.7% of stabilizer.

[0062] The production steps of the EPP board are as follows:

[0063] S11: After mixing EPP particles, nucleating agent and stabilizer evenly, put them into the foaming equipment, heat and melt to 210°C to make the materials mix evenly to form a homogeneous system; then inject the foaming agent under a pressure of 8 MPa, quickly reduce the pressure to foam, and control the foaming ratio to 12 times;

[0064] S12: Cool and shape the EPP blank, and naturally cool it to room temperature; obtain an EPP core material with a density of 45 kg / m 3 and a compressive strength of 1.5 MPa.

[0065] And produce a Pickleball racket according to the process flow of Example 2. Among them, the carbon fiber layer in the surface layer is 0.4 mm thick, the glass fiber layer is 0.1 mm thick, the surface layer is 0.5 mm thick after molding, and the glass fiber layer accounts for 50% of the total mass of the surface layer.

[0066] Example 5

[0067] An EPP board, the raw material components include PP resin with a melt strength of 30 - 40 MPa as the raw material, 1% - 2% AC foaming agent by resin weight, 0.5% - 1% talcum powder nucleating agent, 0.3% - 0.5% stabilizer and carbon fiber, with a length between 5 - 15 mm, and the addition amount of the fiber is 15% of the total weight of EPP.

[0068] The production steps of the EPP board added with short-cut fibers are as follows:

[0069] S21: First, dry the EPP particles to remove the moisture in the EPP particles; evenly mix the EPP particles with the short-cut fibers;

[0070] S22: Foam, the foaming process temperature is 110°C; the pressure is 1.2 MPa; the foaming time is 30 min; control the foaming density to 50 kg / m 3 ;

[0071] S23: After the foaming is completed, cool and shape the EPP foam material.

[0072] Example 6

[0073] An EPP board, the raw material components include PP resin with a melt strength of 35 - 45 MPa as the raw material, add 1.5% - 2.5% CO2 foaming agent by resin weight, 0.8% - 1.2% calcium carbonate nucleating agent and 0.4% - 0.6% stabilizer and aramid fiber, with a length between 5 - 10 mm, and the addition amount of the fiber is 10% of the total weight of EPP.

[0074] The production steps of the EPP board added with short-cut fibers are as follows:

[0075] S21: First, dry the EPP particles to remove the moisture in the EPP particles; evenly mix the EPP particles with the chopped fibers;

[0076] S22: Foam, with the foam process temperature at 120 °C; the pressure at 0.8 MPa; the foam time at 90 min; control the foam density at 35 kg / m 3 ;

[0077] S23: After the foaming is completed, cool and shape the EPP foam material.

[0078] Example 7

[0079] An EPP board, in which the raw material components include PP resin with a melt strength of 40 - 50 MPa as the raw material, adding 2% - 3% AC blowing agent, 1% - 1.5% talc nucleating agent, 0.5% - 0.7% stabilizer, and a mixture of carbon fiber, glass fiber and aramid fiber, with the addition amount being 30% of the total weight of EPP.

[0080] The production steps of the EPP board added with chopped fibers are as follows:

[0081] S21: First, dry the EPP particles to remove the moisture in the EPP particles; evenly mix the EPP particles with the chopped fibers;

[0082] S22: Foam, with the foam process temperature at 130 °C; the pressure at 1.0 MPa; the foam time at 2 h; control the foam density at 67 kg / m 3 ;

[0083] S23: After the foaming is completed, cool and shape the EPP foam material.

[0084] Example 8

[0085] The production steps of a Pickleball racket containing the EPP board of Example 1 or Example 7 are as follows:

[0086] Step 21: In this example, use 100 grams of carbon fiber cloth, and lay five layers of fiber cloth in a cross - laying manner with the 90° - laid fiber cloth 2 and the 0° - laid fiber cloth 3 to increase the strength of the panel;

[0087] Step 22: Adhere the EPP board core 1 after grinding and corona treatment to the laid carbon fiber cloth with epoxy resin adhesive;

[0088] Step 23: Set the molding temperature, pressure, and holding pressure time on the molding press. After reaching the temperature, put the adhered racket into a fixed mold for high - temperature molding;

[0089] Step 24: Demold the molded racket, clean the resin on the edge of the racket after demolding, and grind the burrs and carbon edges on the racket edge at a 45° direction;

[0090] Step 25: Clean the surface. Wipe the surface of the racket with stain remover oil until it is clean and there is no residual lint at the edges.

[0091] Step 26: Install the handle gasket on the racket and reinforce it with pneumatic nails.

[0092] Step 27: Install the back cover and also fix it with pneumatic nails.

[0093] Step 28: Install the PU edge strip to protect the racket frame.

[0094] Step 29: Wrap the handle leather and install the rubber roll to ensure the appearance and comfortable feel of the racket. After these nine steps, the finished racket is obtained.

[0095] Through the above specific implementation methods, a new type of EPP board core Peak racket has been successfully prepared. After actual testing, the racket performs excellently in terms of hitting performance, durability, and comfort.

Claims

1. An EPP board, characterized in that, The raw material components include EPP particles, a foaming agent, a nucleating agent, and a stabilizer.

2. The production process of the EPP board according to claim 1, characterized in that, The steps are as follows: S11: After uniformly mixing the EPP particles, the nucleating agent, and the stabilizer, put them into a foaming device, heat and melt them to 180 - 220 °C to make the materials mix evenly to form a homogeneous system; then inject the foaming agent under a pressure of 8 - 12 MPa, quickly reduce the pressure for foaming, and control the foaming ratio to 10 - 20 times; S12: Cool and shape the EPP blank, and cool it naturally or by forced air cooling to room temperature.

3. The production process of the EPP board according to claim 2, characterized in that, Short-cut fibers are also added to the raw material components of the EPP board; the length of the short-cut fibers is between 5 - 15 mm, and the addition amount of the fibers is 5% - 30% of the total weight of the EPP; The production process steps of the EPP board added with short-cut fibers are as follows: S21: First, dry the EPP particles to remove the moisture in the EPP particles; uniformly mix the EPP particles and the short-cut fibers; S22: Foaming, the foaming process temperature is 110°C - 130°C; the pressure is 0.8 MPa - 1.2 MPa; the foaming time is 30 min - 2 h; control the foaming density to be 30 - 70 kg / m 3 ; S23: After foaming is completed, cool and shape the EPP foam material.

4. The production process of the EPP board according to claim 3, characterized in that, The short-cut fibers are one or a combination of carbon fibers, glass fibers, or aramid fibers.

5. The production process of the EPP board according to claim 3, characterized in that, When the short-cut fibers are carbon fibers or glass fibers, the fiber length is 5 - 10 mm.

6. The production process of the EPP board according to claim 3, characterized in that, When the short-cut fibers are aramid fibers, the addition amount is 5% - 20% of the total weight of the EPP.

7. A Pickleball racket containing the EPP board according to claim 1 or 3, characterized in that, The production steps are as follows: Step 11: Uniformly coat the adhesive on both sides of the cut EPP core material, then cover the non-woven fabric and roll and compound it through a rolling device, and the rolling pressure is 1.5 - 2.5 MPa; Step 12: 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; When the surface layer is a glass fiber base cloth and a carbon fiber base cloth, coat the adhesive on one side of the glass fiber base cloth; Then compound the surface layer to the non-woven fabric layer through a cold pressing device, and the cold pressing pressure is 2 - 3 MPa and the time is 4 - 6 h.

8. A Pickleball racket containing the EPP board according to claim 1 or 3, characterized in that, The production steps are as follows: Step 21: Cross-pave the fiber cloth five layers in the 90° and 0° directions as the surface layer; Step 22: For the EPP board core after surface grinding and corona treatment, paste the surface layer on both sides with epoxy resin adhesive; Step 23: Set the molding temperature, pressure, and pressure holding time of the molding press. After reaching the temperature, put the semi-finished product obtained in Step 22 into a fixed mold for high-temperature molding; Step 24: Demold the molded racket. After demolding, clean the resin on the edge of the racket, and grind the burrs and carbon edges on the edge of the racket flat at a 45° direction; Step 25: Clean the surface, wipe the surface of the racket clean with degreasing oil, and there is no residual hair debris on the edge; Step 26: Install the handle gasket on the racket and reinforce it with an air gun nail; Step 27: Install the back cover and also fix it with an air gun nail; Step 28: Install the PU edge strip to protect the racket frame; Step 29: Wrap the handle leather and install the rubber roll.

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