Aramid-based pickleball racket and preparation method thereof

Abstract

The present invention relates to the technical field of pickle ball rackets, and specifically to an aramid-based pickle ball racket and a preparation method thereof, wherein the pickle ball racket comprises a honeycomb inner core, non-woven fabric layers on both sides of the honeycomb inner core, a panel layer outside the non-woven fabric layer, and a sealing edge strip on the side of the pickle ball racket; the layers are bonded by epoxy resin; the panel layer comprises an inner panel layer and an outer panel layer, the inner panel layer is a carbon fiber layer, and the carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber mixed paper made by mixing carbon fiber and aramid fiber; the outer panel layer is an aramid-based prepreg layer, and the aramid-based prepreg layer is obtained by impregnating epoxy resin with aramid cloth or impregnating epoxy resin with aramid fiber and carbon fiber mixed cloth. The pickle ball racket has a long service life, high elasticity, a large sweet spot, good dimensional stability, and has the advantages of fast hitting speed and good controllability.

Description

Technical Field

[0001] The invention relates to an aramid substrate pickle ball racket and a preparation method thereof, belonging to the technical field of pickle ball rackets. Background Art

[0002] Pickleball is an emerging sport that combines the features of tennis, badminton and table tennis. It is popular among men, women, young and old because it is easy to learn, has low cost and relatively low intensity. Pickleball is not afraid of water, wind or deformation, and the venue used is similar to tennis, so it can be played without obstacles even outdoors.

[0003] The material of the core and panel of a pickleball racket largely determines the elasticity of the racket. When the racket has a high elastic coefficient, the ball decelerates faster. The advantage is that high and far balls are not easy to go out of bounds, and it is easier to control the position and landing point. The lob falls faster because the racket with a high elastic coefficient restores the lower racket surface quickly, and the ball restores quickly, so the deceleration is faster and more sudden.

[0004] In order to improve the elastic coefficient of the racket, Chinese patent application CN118649403A discloses a high-elasticity pickle ball racket, which uses elastic materials to make the racket core, but the high-elastic material has low compression strength, unstable dimensions, and the racket is easily deformed after long-term use; Chinese patent application CN118059452A discloses a pickle ball racket filled with a foamed core reinforcement structure and a preparation method thereof, which uses a foamed core, but the foamed core has low compression strength, unstable dimensions, and the racket is easily deformed after long-term use. In addition, the currently used pickle ball rackets are prone to stratification between the racket and the core during long-term use, which seriously affects the service life of the racket. In order to improve the durability of pickle ball rackets, current domestic market manufacturers often use hot pressing molding technology, but the temperature and pressure process control of hot pressing molding is difficult, which increases the production cost of the enterprise. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides an aramid-based pickle ball racket and a preparation method thereof. The pickle ball racket has the advantages of long service life, high elasticity, large sweet spot, good dimensional stability, fast hitting speed and good controllability.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: an aramid-based pickle ball racket, the pickle ball racket comprising a honeycomb inner core, non-woven fabric layers on both sides of the honeycomb inner core, a panel layer outside the non-woven fabric layer, and a sealing edge strip on the side of the pickle ball racket; the layers are bonded by epoxy resin;

[0007] The panel layer includes an inner panel and an outer panel, wherein the inner panel is a carbon fiber layer, and the carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber mixed paper made by mixing carbon fiber and aramid fiber; the outer panel is an aramid substrate prepreg layer, and the aramid substrate prepreg layer is obtained by impregnating epoxy resin with aramid cloth or impregnating epoxy resin with aramid fiber and carbon fiber mixed cloth;

[0008] The non-woven fabric, aramid fiber and aramid fabric are all cyclically treated with supercritical fluid and modifier and then applied to the pickle ball racket.

[0009] Furthermore, the preparation method of the honeycomb inner core is: aramid fiber is wet-formed and hot-pressed to prepare aramid paper-based materials, the aramid paper-based materials are glued with core strips, and then hot-pressed, stretched, dipped, dried and cured to obtain honeycomb blocks, and the honeycomb blocks are cut to obtain honeycomb core panels;

[0010] The honeycomb core panels are multiple layers connected by bonding and curing with non-woven fabric and epoxy resin to obtain the honeycomb inner core.

[0011] Furthermore, the density of the honeycomb core is 40-70 kg / m 3 , the compressive strength of the honeycomb core panel is ≥2.0MPA.

[0012] Further, the modifier is any one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, dopamine, epichlorohydrin, vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, calcium chloride, lithium chloride, quaternary ammonium starch ether, starch tertiary aminoalkyl ether, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, α-ethyl cyanoacrylate, cyclodextrin, polyvinyl alcohol, and carboxymethyl cellulose.

[0013] Furthermore, the supercritical fluid is carbon dioxide or nitrogen;

[0014] The temperature of the circulation treatment is 32-50° C., the pressure is 7.3-10 MPa, and the time is 1-200 min.

[0015] Furthermore, the mass ratio of the non-woven fabric, aramid fiber or aramid fabric to the modifier is 1:(0.01-100).

[0016] Furthermore, in the carbon fiber layer, the mass proportion of carbon fiber is 20-99wt%, and the mass proportion of aramid fiber is 1-80wt%.

[0017] Furthermore, the length of the carbon fiber is 2-8 mm, the diameter is 8-20 um, and the beating degree of the aramid fiber is 10-70° SR.

[0018] The present invention also discloses a method for preparing an aramid-based pickle ball racket, the preparation method comprising: adhering non-woven fabric layers on both sides of a honeycomb core, adhering an inner panel to the outside of the non-woven fabric layer, adhering an outer panel to the outside of the inner panel, adhering the layers together by epoxy resin, hot-pressing the layers after assembly, and then cutting them, adhering sealing edge strips to the sides to obtain the pickle ball racket.

[0019] Furthermore, the temperature of the hot pressing molding is 100-150° C., and the pressure of the hot pressing molding is 200-700N.

[0020] The beneficial effects of the present invention are:

[0021] The racket core of the present invention adopts a multi-layer aramid honeycomb core material, which can effectively reduce the vibration when hitting the ball, so that players can maintain a good feel during long-term competitions. The compression strength of the honeycomb core is greater; the racket is not easily deformed due to the high compression strength; the aramid honeycomb core material is prepared using an aramid paper-based material with high tear strength, and short-cut fibers of different lengths effectively improve the tear strength of the aramid paper-based material, thereby improving the compression strength of the aramid honeycomb core material, ensuring that the racket is not easily deformed.

[0022] The non-woven fabric pretreated with a modifier is used between the honeycomb inner core and the panel of the present invention. After the non-woven fabric is pretreated with the modifier, the functional groups of the modifier are introduced into the surface of the non-woven fabric, and chemical bonds are introduced, which effectively improves the bonding effect between the panel and the inner core, avoids stratification during the use of the racket, and increases the service life of the racket.

[0023] The inner panel of the present invention adopts carbon fiber paper-based material. The carbon fiber two-dimensional material prepared by papermaking technology has randomly distributed carbon fibers, so that the buffering effect produced by the carbon fiber layer is better and the sweet spot area of ​​the racket is increased. The outer layer adopts aramid prepreg to increase the elasticity of the racket. Under the condition of the same racket surface deformation, because the aramid prepreg has high elasticity and fast recovery, the pickle ball maintains deformation time for a shorter time and decelerates faster. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 A schematic diagram of the layer structure of the pickleball racket of the present invention;

[0025] In the figure, 1. honeycomb core; 2. non-woven fabric layer; 3. inner panel; 4. outer panel. DETAILED DESCRIPTION

[0026] The specific implementation of the present invention is described in detail below. The present invention can be implemented in many other ways than those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed.

[0027] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used are only for describing specific embodiments and are not intended to limit the present invention.

[0028] A pickle ball racket made of aramid fiber, comprising a honeycomb inner core 1, non-woven fabric layers 2 on both sides of the honeycomb inner core 1, a panel layer outside the non-woven fabric layer 2, and a sealing edge strip on the side of the pickle ball racket; each layer is bonded by epoxy resin;

[0029] The panel layer includes an inner panel 3 and an outer panel 4, the inner panel 3 is a carbon fiber layer, and the carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber mixed paper obtained by mixing carbon fiber and aramid fiber; the outer panel 4 is an aramid base material prepreg layer, and the aramid base material prepreg layer is obtained by impregnating epoxy resin with aramid cloth or by impregnating epoxy resin with aramid fiber and carbon fiber blended cloth.

[0030] Specifically, the preparation method of the honeycomb inner core 1 is: aramid fiber is wet-formed and hot-pressed to prepare aramid paper-based materials, the aramid paper-based materials are glued with core strips, and then hot-pressed, stretched, dipped, dried and cured to obtain honeycomb blocks, and the honeycomb blocks are cut to obtain honeycomb core panels;

[0031] The honeycomb core panels are bonded and cured by non-woven fabric and epoxy resin to obtain the honeycomb inner core 1.

[0032] More specifically, the cell sizes of the multi-layer honeycomb core 1 are the same or different.

[0033] More specifically, the process conditions of hot pressing, stretching, dipping, drying and curing in preparing the honeycomb core panel belong to the known technology, and the specific process parameters are determined according to the actual production needs.

[0034] Specifically, the density of the honeycomb core 1 is 40-70 kg / m 3 , the compressive strength of the honeycomb core panel is ≥2.0MPA.

[0035] Specifically, the non-woven fabric, aramid fiber, and aramid fabric are all treated by supercritical fluid and modifier circulation and then applied to the pickle ball racket; the modifier is introduced into the surface of the aramid fiber and the non-woven fabric;

[0036] The modifier is any one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, dopamine, epichlorohydrin, vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, calcium chloride, lithium chloride, quaternary ammonium starch ether, starch tertiary aminoalkyl ether, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, α-ethyl cyanoacrylate, cyclodextrin, polyvinyl alcohol, and carboxymethyl cellulose.

[0037] Specifically, the supercritical fluid is carbon dioxide or nitrogen;

[0038] The temperature of the circulation treatment is 32-50° C., the pressure is 7.3-10 MPa, and the time is 1-200 min.

[0039] Specifically, the mass ratio of the non-woven fabric, aramid fiber or aramid fabric to the modifier is 1:(0.01-100).

[0040] More specifically, the delamination peeling strength of the non-woven fabric layer 2 is ≥1.5 N / cm, and the delamination peeling strength of the modified non-woven fabric layer 2 is ≥2.5 N / cm.

[0041] Specifically, in the carbon fiber layer, the mass proportion of carbon fiber is 20-99wt%, and the mass proportion of aramid fiber is 1-80wt%.

[0042] Specifically, the length of the carbon fiber is 2-8 mm, the diameter is 8-20 um, and the beating degree of the aramid fiber is 10-70° SR.

[0043] Carbon fiber and aramid fiber are pulped, papered, hot pressed, cut and impregnated to obtain carbon fiber two-dimensional material. The carbon fiber two-dimensional material obtained by this papermaking method has random distribution of carbon fibers, and the buffering effect of the carbon fiber layer is better.

[0044] More specifically, the pulping process uses a dispersant to keep the carbon fiber and aramid fiber in a uniformly dispersed state, such as polyvinyl alcohol, cationic polyacrylamide, carboxymethyl cellulose, anionic polyacrylamide, nonionic polyacrylamide, and sodium alginate.

[0045] More specifically, the aramid fiber is at least one of meta-aramid filaments, meta-aramid chopped fibers, para-aramid filaments, para-aramid chopped fibers, meta-aramid fibrids, meta-aramid pulp, and para-aramid pulp.

[0046] More specifically, the thickness of the honeycomb core 1 is 13.5-15.5 mm; the weight of each non-woven fabric layer 2 is 30-200 g / m 2The thickness of each layer of the inner panel 3 is 0.3-0.4 mm; the thickness of each layer of the outer panel 4 is 0.3-0.35 mm.

[0047] A method for preparing an aramid-based pickle ball racket, the method comprising: adhering non-woven fabric layers 2 on both sides of a honeycomb core 1, adhering an inner panel 3 on the outside of the non-woven fabric layer 2, adhering an outer panel 4 on the outside of the inner panel 3, adhering the layers together with epoxy resin, hot-pressing the layers after assembly, and then cutting them, adhering sealing edge strips on the sides to obtain the pickle ball racket.

[0048] Specifically, the temperature of the hot pressing molding is 100-150° C., and the pressure of the hot pressing molding is 200-700N.

[0049] The relevant raw material information used in the embodiments of the present invention is as follows, but this is not a limitation to the technical solution of the present invention:

[0050] Epoxy resin: E51 epoxy resin;

[0051] Non-woven fabric: polypropylene non-woven fabric, polyester non-woven fabric, etc.

[0052] Carbon fiber: T700, T800, Weihai Tuozhan Fiber Co., Ltd.

[0053] Aramid fiber: The meta-aramid fiber and para-aramid fiber used are produced by Taihe New Materials Group Co., Ltd.

[0054] Aramid fabric: It is woven with 1500D para-aramid colored filament from Taihe New Materials Group Co., Ltd. The common patterns are twill, I-shaped and jacquard, with a basis weight of 200-230g / m 2 , thickness is about 0.3mm, and the glue content is 30-50%.

[0055] Core adhesive: J-80 paper honeycomb sandwich adhesive produced by Heilongjiang Institute of Chemistry.

[0056] Example 1

[0057] (1) Modification of aramid fibers, non-woven fabrics, and aramid fabrics:

[0058] Aramid fibers (meta-aramid chopped fibers 2D 6mm, meta-aramid fibrids), nonwoven fabrics (quantity 30g / m 2 The polyester non-woven fabric), aramid fabric (para-aramid fabric) are subjected to a cyclic treatment of carbon dioxide supercritical fluid and a modifier to obtain modified aramid fibers, non-woven fabrics, and aramid fabrics; the aramid fibers, non-woven fabrics, and aramid fabrics used in subsequent steps are all modified aramid fibers, non-woven fabrics, and aramid fabrics;

[0059] The modifier is toluene diisocyanate, the temperature of the circulation treatment is 40°C, the pressure is 8.5 MPa, and the time is 30 minutes; the mass ratio of the aramid fiber, non-woven fabric or aramid fabric to the modifier is 1:30.

[0060] (2) Preparation of honeycomb core 1:

[0061] Aramid fibers (the mass ratio of meta-aramid chopped fibers to meta-aramid fibrils is 1:1) are wet-papered and hot-pressed to prepare aramid paper-based materials. Core strip glue is applied between the aramid paper-based materials, and then hot-pressed, stretched, dipped in glue, dried and cured to obtain honeycomb blocks. The honeycomb blocks are cut to obtain honeycomb core panels. The three layers of the honeycomb core panels are bonded together by non-woven fabrics and epoxy resin (E51 epoxy resin) to obtain a honeycomb inner core 1.

[0062] (3) Preparation of carbon fiber layer (inner panel 3):

[0063] The carbon fiber layer is obtained by mixing carbon fiber (T700) and aramid fiber (the mass ratio of meta-aramid chopped fiber to meta-aramid fibrid is 1:2) and impregnating epoxy resin into carbon fiber mixed paper; the mass proportion of carbon fiber is 50wt%, and the mass proportion of aramid fiber is 50wt%. The length of carbon fiber is 4mm, the diameter is 15um, and the beating degree of meta-aramid fibrid is 60°SR.

[0064] (4) Preparation of aramid substrate prepreg layer (outer panel 4):

[0065] The aramid cloth is impregnated with epoxy resin to obtain the aramid base material prepreg layer.

[0066] (5) Preparation of pickleball rackets:

[0067] like Figure 1 As shown, non-woven fabric layers 2 are adhered to both sides of the honeycomb core 1, inner panel 3 is adhered to the outside of the non-woven fabric layer 2, outer panel 4 is adhered to the outside of the inner panel 3, and each layer is adhered by epoxy resin. After the layers are assembled, they are hot-pressed and then cut, and sealing edge strips are adhered to the sides to obtain the pickle ball racket.

[0068] Wherein, the temperature of the hot pressing molding is 120°C, and the pressure of the hot pressing molding is 500N.

[0069] Example 2

[0070] (1) Modification of aramid fibers and non-woven fabrics:

[0071] Aramid fibers (para-aramid filament fiber 1500D, para-aramid short fiber 2D 9mm, para-aramid pulp fiber), non-woven fabric (basis weight 30g / m 2The polypropylene non-woven fabric) is subjected to a cyclic treatment of carbon dioxide supercritical fluid and a modifier to obtain a modified aramid fiber and a non-woven fabric; the aramid fiber and the non-woven fabric used in the subsequent steps are all the modified aramid fiber and the non-woven fabric;

[0072] The modifier is dopamine, the temperature of the circulation treatment is 32°C, the pressure is 10MPa, and the time is 200min; the mass ratio of the aramid fiber or non-woven fabric to the modifier is 1:0.01.

[0073] (2) Preparation of honeycomb core 1:

[0074] Aramid fibers (the mass ratio of para-aramid short fibers to para-aramid pulp fibers is 1:2) are wet-papered and hot-pressed to prepare aramid paper-based materials. The aramid paper-based materials are bonded with core strips of glue, and then hot-pressed, stretched, dipped in glue, dried and cured to obtain honeycomb blocks. The honeycomb blocks are cut to obtain honeycomb core panels. The three layers of honeycomb core panels are bonded with non-woven fabrics and epoxy resin (E51 epoxy resin) to obtain a honeycomb inner core 1.

[0075] (3) Preparation of carbon fiber layer (inner panel 3):

[0076] The carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber mixed paper made by mixing carbon fiber (T800) and aramid fiber (the mass ratio of para-aramid short fiber and para-aramid pulp fiber is 1:1); the mass proportion of carbon fiber is 20wt%, and the mass proportion of aramid fiber is 80wt%. The length of carbon fiber is 8mm, the diameter is 20um, and the beating degree of para-aramid pulp fiber is 20°SR.

[0077] (4) Preparation of aramid substrate prepreg layer (outer panel 4):

[0078] A woven fabric of aramid fiber (para-aramid filament fiber 1500D) and 3K carbon fiber filament is impregnated with epoxy resin to obtain the aramid substrate prepreg layer, and the mass ratio of aramid fiber to carbon fiber in the aramid substrate prepreg layer is 5:1.

[0079] (5) Preparation of pickleball rackets:

[0080] like Figure 1 As shown, non-woven fabric layers 2 are adhered to both sides of the honeycomb core 1, inner panel 3 is adhered to the outside of the non-woven fabric layer 2, outer panel 4 is adhered to the outside of the inner panel 3, and each layer is adhered by epoxy resin. After the layers are assembled, they are hot-pressed and then cut, and sealing edge strips are adhered to the sides to obtain the pickle ball racket.

[0081] Wherein, the temperature of the hot pressing molding is 100°C, and the pressure of the hot pressing molding is 700N.

[0082] Example 3

[0083] (1) Modification of aramid fibers and non-woven fabrics:

[0084] Aramid fibers (para-aramid filament fiber 1500D, meta-aramid short fiber 2D 8mm, meta-aramid pulp fiber), non-woven fabric (basis weight 40g / m 2 The polyester non-woven fabric) is subjected to a cyclic treatment of carbon dioxide supercritical fluid and a modifier to obtain a modified aramid fiber and a non-woven fabric; the aramid fiber and the non-woven fabric used in the subsequent steps are all the modified aramid fiber and the non-woven fabric;

[0085] The modifier is epichlorohydrin, the temperature of the circulation treatment is 50°C, the pressure is 7.3 MPa, and the time is 1 min; the mass ratio of the aramid fiber or non-woven fabric to the modifier is 1:100.

[0086] (2) Preparation of honeycomb core 1:

[0087] Aramid fibers (the mass ratio of meta-aramid short fibers to meta-aramid pulp fibers is 4:1) are wet-papered and hot-pressed to prepare aramid paper-based materials. The aramid paper-based materials are bonded with core strips of glue, and then hot-pressed, stretched, dipped, dried and cured to obtain honeycomb blocks. The honeycomb blocks are cut to obtain honeycomb core panels. The three layers of the honeycomb core panels are bonded together by non-woven fabrics and epoxy resin (E51 epoxy resin) to obtain a honeycomb inner core 1.

[0088] (3) Preparation of carbon fiber layer (inner panel 3):

[0089] The carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber (T700) mixed paper made by mixing carbon fiber and aramid fiber (the mass ratio of meta-aramid short fiber and meta-aramid pulp fiber is 1:4); the mass proportion of carbon fiber is 99wt%, and the mass proportion of aramid fiber is 1wt%. The length of carbon fiber is 2mm, the diameter is 8um, and the beating degree of meta-aramid pulp fiber is 40°SR.

[0090] (4) Preparation of aramid substrate prepreg layer (outer panel 4):

[0091] Aramid fiber (para-aramid filament 1500D) and 3K carbon fiber blended fabric is impregnated with epoxy resin to obtain the aramid base material prepreg layer, and the mass ratio of aramid fiber to carbon fiber in the aramid base material prepreg layer is 1:1.

[0092] (5) Preparation of pickleball rackets:

[0093] like Figure 1As shown, non-woven fabric layers 2 are adhered to both sides of the honeycomb core 1, inner panel 3 is adhered to the outside of the non-woven fabric layer 2, outer panel 4 is adhered to the outside of the inner panel 3, and each layer is adhered by epoxy resin. After the layers are assembled, they are hot-pressed and then cut, and sealing edge strips are adhered to the sides to obtain the pickle ball racket.

[0094] Wherein, the temperature of the hot pressing molding is 150°C, and the pressure of the hot pressing molding is 200N.

[0095] Example 4

[0096] (1) Modification of aramid fibers, non-woven fabrics, and aramid fabrics:

[0097] Aramid fiber (meta-aramid short fiber 2.2D 5mm, para-aramid pulp fiber), non-woven fabric (basis weight 50g / m 2 The meta-aramid spunlace nonwoven fabric), aramid fabric (para-aramid fabric) are cyclically treated with carbon dioxide supercritical fluid and a modifier to obtain modified aramid fibers, nonwoven fabrics, and aramid fabrics; the aramid fibers, nonwoven fabrics, and aramid fabrics used in subsequent steps are all modified aramid fibers, nonwoven fabrics, and aramid fabrics;

[0098] The modifier is lithium chloride, the temperature of the circulation treatment is 45°C, the pressure is 8 MPa, and the time is 60 min; the mass ratio of the aramid fiber, non-woven fabric or aramid fabric to the modifier is 1:50.

[0099] (2) Preparation of honeycomb core 1:

[0100] Aramid fibers (the mass ratio of meta-aramid short fibers to para-aramid pulp fibers is 1:1) are wet-papered and hot-pressed to prepare aramid paper-based materials. The aramid paper-based materials are glued with core strips, and then hot-pressed, stretched, dipped, dried and cured to obtain honeycomb blocks. The honeycomb blocks are cut to obtain honeycomb core panels. The three layers of the honeycomb core panels are bonded together by non-woven fabrics and epoxy resin (E51 epoxy resin) to obtain a honeycomb inner core 1.

[0101] (3) Preparation of carbon fiber layer (inner panel 3):

[0102] The carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber mixed paper made by mixing carbon fiber (T800) and aramid fiber (the mass ratio of meta-aramid short fiber and para-aramid pulp fiber is 1:1); the mass proportion of carbon fiber is 30wt%, and the mass proportion of aramid fiber is 70wt%. The length of carbon fiber is 3mm, the diameter is 20um, and the beating degree of para-aramid pulp fiber is 20°SR.

[0103] (4) Preparation of aramid substrate prepreg layer (outer panel 4):

[0104] The aramid cloth is impregnated with epoxy resin to obtain the aramid base material prepreg layer.

[0105] (5) Preparation of pickleball rackets:

[0106] like Figure 1 As shown, non-woven fabric layers 2 are adhered to both sides of the honeycomb core 1, inner panel 3 is adhered to the outside of the non-woven fabric layer 2, outer panel 4 is adhered to the outside of the inner panel 3, and each layer is adhered by epoxy resin. After the layers are assembled, they are hot-pressed and then cut, and sealing edge strips are adhered to the sides to obtain the pickle ball racket.

[0107] Wherein, the temperature of the hot pressing molding is 120°C, and the pressure of the hot pressing molding is 450N.

[0108] Comparative Example 1

[0109] The pickleball racket was prepared by the same method as in Example 1, except that the aramid fiber, non-woven fabric and aramid fabric were not modified.

[0110] Comparative Example 2

[0111] A pickleball racket is prepared by the same method as in Example 1, except that in this comparative example 2, the honeycomb core 1 of the aramid paper-based material is replaced with a conventional PP honeycomb core 1 .

[0112] The preparation method of the PP honeycomb core 1 in this comparative example 2 is:

[0113] 1200HS PP particles and 10% PP particle mass POE particles are respectively extracted and injected into two extruders for plasticization and extrusion, and a PP tube wrapped with a POE film on the outside is formed by co-extrusion, the PP particle extruder contains seven interval temperatures, each of which is 170, 180, 190, 208, 212, 215, 215°C, the temperature fluctuation is controlled within ±2°C, and the screw speed is controlled to 605±1rpm, and the POE particle extruder contains 5 interval temperatures, each of which is 224, 230, 235, 240, 240°C, the temperature fluctuation is controlled within ±2°C, and the screw speed is controlled to 230±1rpm; then vacuum water cooling is performed to form a PP tube with an outer diameter of 6mm and a thickness of 0.15mm, and the outside of the PP tube is extruded by the POE extruder to form a POE film with a thickness of 0.01mm;

[0114] The PP tubes are cut into a certain length and arranged in a mold, and then sent into an oven to heat-melt the POE film so that the PP tubes are bonded to each other. The heat-melting temperature of the oven for the POE film is 125° C. and the baking time is 15 minutes. After cooling, a honeycomb component is obtained;

[0115] The honeycomb components are hot cut to form a PP honeycomb panel, and then both sides are leveled by grinding, etc., so as to obtain a PP honeycomb core 1 of required thickness. The thickness of the PP honeycomb core 1 of this comparative example 1 is the same as the thickness of the honeycomb core 1 of the aramid paper-based material in Example 1.

[0116] Comparative Example 3

[0117] The pickle ball racket was prepared by the same method as in Example 1, except that: in this comparative example 3, no non-woven fabric layer 2 was assembled between the honeycomb core 1 and the inner panel 3, and they were bonded and cured by epoxy resin.

[0118] Comparative Example 4

[0119] The pickleball racket was prepared in the same manner as in Example 1, except that no aramid fiber was added to the carbon fiber layer (inner panel 3) of Comparative Example 4.

[0120] Comparative Example 5

[0121] The pickleball racket was prepared by the same method as in Example 1, except that the outer panel 4 of this comparative example 5 was replaced with a glass fiber board of the same thickness.

[0122] Comparative Example 6

[0123] The pickleball racket is prepared by the same method as in Example 1, except that the outer panel 4 of this comparative example 6 is replaced with a carbon fiber board of the same thickness.

[0124] The performance of the pickle ball rackets prepared in the above embodiments and comparative examples was tested, and the specific results are shown in Table 1. The test methods involved are:

[0125] Honeycomb core 1 density: GB / T1464-2005;

[0126] Plane compression strength: GB / T1453-2005;

[0127] Refer to UPA-A's racket certification standards:

[0128] Ball speed: Use the most common driving method to measure the maximum flight speed of the ball.

[0129] Spin Test: Measures the maximum spin rate a ball can achieve.

[0130] Spin test (after one month): 10 rackets were tested in each group, and each racket was hit 500 times a day. Spin test was performed after one month.

[0131] Whether there is delamination after three months: 10 rackets are tested in each group, and each racket is hit 500 times a day to test whether the racket is delaminated after three months.

[0132] Acoustic test: GB / T3096-2008.

[0133] Table 1 Pickleball racket performance test data

[0134]

[0135] It can be seen from the data in the above table that the pickle ball rackets prepared by the preparation method of the present invention in Examples 1 to 4 have long service life, high elasticity, large sweet spot, good dimensional stability, and have the advantages of fast hitting speed and good controllability.

[0136] From the comparison of the data of Comparative Example 1 and Example 1, it can be seen that if the aramid fiber, non-woven fabric and aramid cloth are not modified, the compression strength of the honeycomb core 1 will be low, the rotation speed will drop rapidly after one month, and the panel and the core will be delaminated after the racket is used for 3 months. After the aramid fiber, non-woven fabric and aramid cloth are pre-treated with a modifier, the functional groups of the modifier are introduced into the fiber substrate and the epoxy resin surface, and chemical bonds are introduced, which effectively improves the bonding effect between the aramid substrate and the epoxy resin in the racket, avoids delamination during the use of the racket, and increases the service life of the racket.

[0137] From the data comparison between Comparative Example 2 and Example 1, it can be seen that if the honeycomb core 1 of the aramid paper-based material is replaced with a conventional PP honeycomb core 1, the compression strength of the honeycomb core 1 will be low and the hitting speed will be low. This is because the modulus of PP is not as high as that of the aramid honeycomb core 1, the compression strength of the honeycomb core 1 is low and the honeycomb size is easily deformed, and the panel and the honeycomb core 1 will be delaminated after long-term use.

[0138] From the comparison of the data of Comparative Example 3 and Example 1, it can be seen that if the non-woven fabric layer 2 is not assembled between the honeycomb core 1 and the inner panel 3, the racket will be severely delaminated after one month of use, and the racket will be noisy. This is because the honeycomb core 1 is in direct contact with the panel and there is a lack of an effective buffer layer. After long-term impact, the epoxy resin at the connection point breaks, causing the racket to be delaminated.

[0139] From the comparison of the data of Comparative Example 4 and Example 1, it can be seen that if aramid fiber is not added to the carbon fiber layer (inner layer panel 3), it will lead to loud hitting noise, low hitting speed and low rotation speed. Because the carbon fiber two-dimensional material prepared by papermaking technology has randomly distributed carbon fibers inside, the carbon fiber layer has a better buffering effect, reduced hitting noise, fast hitting speed and rotation speed, and increased sweet spot area of ​​the racket.

[0140] From the data comparison of comparative example 5 and embodiment 1, it can be seen that if the outer panel 4 is replaced with a glass fiber board, the hitting speed will be low, the rotation speed will decrease after one month, and the hitting sound will be loud, because the outer panel 4 is made of aramid prepreg, which increases the elasticity of the racket. Under the same racket surface deformation, the aramid prepreg has high elasticity and fast recovery, so the pickle ball maintains deformation time shorter and decelerates faster. However, the glass fiber board has poor elasticity and slow recovery, and is seriously worn after long-term use.

[0141] From the data comparison between Comparative Example 6 and Example 1, it can be seen that if the outer panel 4 is replaced with a carbon fiber panel, the rotation speed will be significantly reduced after one month, because the rotation life of the racket is directly related to the outer panel 4. The carbon fiber panel has low elasticity and slow recovery. After long-term use, the surface is obviously damaged, resulting in a significant decrease in the rotation speed after one month. The aramid prepreg has high elasticity, fast recovery, and is wear-resistant and has a long service life.

[0142] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0143] For those skilled in the art, several modifications and improvements may be made without departing from the concept of the present invention, all of which belong to the protection scope of the present invention. The protection scope of the present invention shall be based on the attached claims.

Claims

1. An aramid-based pickleball racket, characterized in that: The pickle ball racket comprises a honeycomb inner core, non-woven fabric layers on both sides of the honeycomb inner core, a panel layer outside the non-woven fabric layer, and a sealing edge strip on the side of the pickle ball racket; each layer is bonded by epoxy resin; The panel layer includes an inner panel and an outer panel, wherein the inner panel is a carbon fiber layer, and the carbon fiber layer is obtained by impregnating epoxy resin with carbon fiber mixed paper made by mixing carbon fiber and aramid fiber; the outer panel is an aramid substrate prepreg layer, and the aramid substrate prepreg layer is obtained by impregnating epoxy resin with aramid cloth or impregnating epoxy resin with aramid fiber and carbon fiber mixed cloth; The nonwoven fabric, aramid fiber, and aramid fabric are all treated by supercritical fluid and modifier circulation and then applied to the pickleball racket; The modifier is any one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, dopamine, epichlorohydrin, vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tri(β-methoxyethoxy)silane, calcium chloride, lithium chloride, quaternary ammonium starch ether, starch tertiary aminoalkyl ether, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, α-ethyl cyanoacrylate, cyclodextrin, polyvinyl alcohol, and carboxymethyl cellulose.

2. The aramid-based pickleball racket according to claim 1, characterized in that: The preparation method of the honeycomb inner core is as follows: aramid fibers are wet-coated and hot-pressed to prepare aramid paper-based materials, the aramid paper-based materials are glued with core strips, and then hot-pressed, stretched, dipped, dried and cured to obtain honeycomb blocks, and the honeycomb blocks are cut to obtain honeycomb core panels; The honeycomb core panels are multiple layers connected by bonding and curing with non-woven fabric and epoxy resin to obtain the honeycomb inner core.

3. The aramid-based pickleball racket according to claim 2, characterized in that: The density of the honeycomb core is 40-70 kg / m 3 , the compressive strength of the honeycomb core panel is ≥2.0MPa.

4. The aramid-based pickleball racket according to claim 1, characterized in that: The supercritical fluid is carbon dioxide or nitrogen; The temperature of the circulation treatment is 32-50° C., the pressure is 7.3-10 MPa, and the time is 1-200 min.

5. The aramid-based pickleball racket according to claim 1, characterized in that: The mass ratio of the non-woven fabric, aramid fiber or aramid fabric to the modifier is 1:(0.01-100).

6. The aramid-based pickleball racket according to claim 1, characterized in that: In the carbon fiber layer, the mass proportion of carbon fiber is 20-99wt%, and the mass proportion of aramid fiber is 1-80wt%.

7. The aramid-based pickleball racket according to claim 1, characterized in that: In the carbon fiber layer, the length of the carbon fiber is 2-8 mm, the diameter is 8-20 um, and the beating degree of the aramid fiber is 10-70° SR.

8. A method for preparing an aramid-based pickle ball racket according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: adhering non-woven fabric layers to both sides of a honeycomb core, adhering an inner panel to the outside of the non-woven fabric layers, adhering an outer panel to the outside of the inner panel, adhering the layers to each other through epoxy resin, assembling the layers, hot pressing and then cutting, adhering sealing edge strips to the sides, and obtaining the pickle ball racket.

9. The method for preparing a pickle ball racket made of aramid fiber as claimed in claim 8, characterized in that: The temperature of the hot pressing molding is 100-150° C., and the pressure of the hot pressing molding is 200-700N.

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