A pp honeycomb core badminton racket and a preparation method thereof

Abstract

The application discloses a PP honeycomb core piquet, which comprises a piquet body, non-woven fabric layers arranged on both sides of the piquet body, surface layers arranged on the outer sides of the non-woven fabric layers, and edges arranged on the edges of the piquet body, wherein the piquet body is formed by a plurality of PP tubes with a diameter of 6-8 mm, the PP tubes are hot-melted to form a PP honeycomb core plate with a honeycomb plate structure, the thickness of the PP honeycomb core plate is 12-14 mm, the density of the PP honeycomb core plate is 65-70 kg / m 3 , and the compression strength of the prepared PP honeycomb core plate is greater than or equal to 1.2 MPA. The PP honeycomb core piquet is lighter, the compression strength is improved, the problem that the handle of the PP honeycomb core piquet is prone to breakage due to insufficient compression strength is solved, and the overall structure is simple and better in elasticity.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sports equipment, and particularly relates to a PP honeycomb core pickleball racket and a preparation method thereof. BACKGROUND

[0002] Pickleball is a sport played with a racket, which originated in Bainbridge Island, Seattle, USA, and is a combination of tennis, badminton and table tennis. The activity and exercise amount of pickleball is smaller than that of tennis, and is suitable for people of all ages, so it has gradually become popular and is loved by the public in recent years.

[0003] A common pickleball racket is made of wood or carbon fiber or glass fiber. The wooden one has been basically eliminated due to its material, and when made of carbon fiber or glass fiber, it needs to be compounded with a middle composite board, which has a complex process and high cost, and the overall weight is heavy, the compressive strength is small, especially on the racket with light weight requirement, the handle is easy to break, the elasticity is small, etc. When the athletes are exercising, the heavy weight of the racket is easy to make the arm sore or the wrist injured, and when the elasticity is poor, the durability is relatively poor and the service life is short, which not only causes certain economic loss, but also has a certain safety hazard, causing certain danger to the athletes. And the existing pickleball racket has a small range of raw material selection. Therefore, in recent years, pickleball rackets with honeycomb board as the racket core have also appeared, which relatively solve the problem of heavy weight of the existing racket, but when the conventional pp tube is made into a racket, generally about 10% of PE is mixed, and in the case of 65 kg per cubic meter, the compressive strength is generally about 0.8 MPA. When the thickness of the pickleball racket is 18 mm or less, the handle is easy to break, especially when the thickness of the PP honeycomb board is 14 mm and the density is 65 kg / m3. Because the weight is relatively light, the wall thickness of the pp tube is relatively thick, which makes the density fluctuation of the honeycomb board relatively large during the production process by the conventional production process, so that the pp tube is easy to break during extrusion by the extruder. At the same time, due to the thin wall thickness of the pp tube, the general baking temperature is easy to form a collapse phenomenon when entering the oven for baking. Similarly, due to the thin wall thickness, the handle and the racket surface of the pickleball racket are easy to break due to excessive stress, and the elasticity of the racket is not improved.

[0004] Meanwhile, the material of the racket face is also an important factor to determine the elasticity of the racket, which determines how much force is absorbed or returned to the ball by the racket. The existing face layer material is generally carbon fiber, glass fiber or graphite material, and the conventional single layer material or the combination of multiple materials can meet the demand, but the elasticity cannot be obviously improved, resulting in a feeling of insufficient elasticity when the user hits the ball, and the durability and service life are short. Therefore, when manufacturing a PP honeycomb core pike racket with light weight, high compressive strength and good elasticity, not only the existing PP honeycomb plate needs to be improved, but also the face layer of the racket needs to be improved, so that the pike racket can be made to a thickness of 14mm or less and a density of 65kg / m 3 , and the overall compressive strength of the racket can be guaranteed, the elasticity of the racket to the ball is improved, so that the racket is lighter and the ball is more labor-saving. SUMMARY

[0005] In order to solve the technical problems existing in the prior art, one of the purposes of the present application is to provide a PP honeycomb core pike racket, which can manufacture a lighter PP honeycomb core pike racket while improving its compressive strength, solving the problem of easy breakage of the handle of the PP honeycomb core pike racket due to insufficient compressive strength, and having a simple overall structure and better elasticity.

[0006] The second purpose of the present application is to provide a preparation method of a PP honeycomb core pike racket, which has a simple manufacturing process and can manufacture a lighter honeycomb core plate while ensuring the density of the PP pipe to be stable, so that the PP pipe is not prone to breakage when extruded by the extruder, especially when entering the oven for baking.

[0007] To solve the above-mentioned technical problems, one of the purposes of the present application adopts the following technical scheme:

[0008] A PP honeycomb core pike racket, comprising a racket main body, a non-woven fabric layer arranged on both sides of the racket main body, a face layer arranged on the outer side of the non-woven fabric layer, and a binding edge wrapped around the edge of the racket main body, wherein the racket main body is a PP honeycomb core plate formed by a plurality of PP pipes with a diameter of 6-8mm, the PP honeycomb core plate has a thickness of 12-14mm and a density of 65-70kg / m 3 , and the compressive strength of the prepared PP honeycomb core plate is greater than or equal to 1.2MPA.

[0009] Preferably, the PP pipe is formed by hot melting and extruding PP particles of 1200HS, and the diameter of the PP pipe is 6mm and the wall thickness is 0.15mm.

[0010] Preferably, the outer surface of the PP pipe is covered with a POE adhesive film, and the adjacent two PP pipes are bonded by the POE adhesive film.

[0011] Preferably, the surface layer comprises a carbon fiber layer and a glass fiber layer, and the surface layer is attached to the non-woven fabric layer through the glass fiber layer.

[0012] Preferably, the glass fiber layer is composed of an epoxy glass fiber prepreg sheet with a thickness of 0.2 mm, and the carbon fiber layer is composed of an epoxy carbon fiber prepreg sheet with a thickness of 0.2 mm, and the carbon fiber layer and the glass fiber layer are formed by molding.

[0013] Preferably, the non-woven fabric layer is a PET non-woven fabric, and the PET non-woven fabric is bonded to the racket body and the surface layer through a PP non-woven fabric film, and the grammage ratio of the PET non-woven fabric and the PP non-woven fabric film is 2:1.

[0014] The second purpose of the present application is achieved by the following technical scheme:

[0015] A preparation method of a PP honeycomb core pickleball racket, comprising a PP honeycomb core pickleball racket, the preparation method of the PP honeycomb core pickleball racket comprising

[0016] S1, the PP particles and POE particles of 1200HS are respectively extracted and injected into two plasticizing extruders for extrusion, and then the PP tube wrapped with POE film on the outside is formed after co-extrusion, and then vacuum water cooling is performed to form a PP tube with an outer diameter of 6-8mm and a thickness of 0.15-0.2mm, and the thickness of the POE film of the PP tube is 0.01mm;

[0017] S2, the PP tube is cut to a certain length and arranged in a mold, and then the POE film is heated and melted in an oven to bond the PP tubes to each other, and then a honeycomb part is obtained after cooling;

[0018] S3, the honeycomb part is hot cut and formed to obtain a PP honeycomb core plate with a required thickness, and the density of the honeycomb core of the PP honeycomb core plate is 65-70kg / m 3 , and the compressive strength is ≥1.2MP;

[0019] S4, a PET non-woven fabric layer is compounded on both sides of the PP honeycomb core plate to form a non-woven fabric honeycomb core;

[0020] S5, the glass fiber base cloth and the carbon fiber base cloth are pre-impregnated with epoxy resin to form an epoxy glass fiber prepreg sheet and an epoxy carbon fiber prepreg sheet, and the epoxy glass fiber prepreg sheet and the epoxy carbon fiber prepreg sheet are laminated and hot pressed to form a surface layer;

[0021] S6, glue the glass fiber base cloth on one side of the surface layer by a gluing machine and cold press, and then compound the surface layer on the surface of the non-woven fabric honeycomb core to form a pickleball plate;

[0022] S7, forming a bare racket of the pickleball after engraving the pickleball racket plate;

[0023] S8, forming a pickleball racket after UV printing and edge wrapping of the bare racket of the pickleball.

[0024] Preferably, the PP particle extruder contains seven interval temperatures, each interval temperature is 170, 180, 190, 208, 212, 215, 215℃ in turn, the temperature fluctuation is controlled within ±2℃, the screw speed is controlled at 605±1rpm, the POE particle extruder contains five interval temperatures, each interval temperature is 224, 230, 235, 240, 240℃, the temperature fluctuation is controlled within ±2℃, and the screw speed is controlled at 230±1rpm.

[0025] Preferably, the hot melting temperature of the POE film in the oven is 120-125℃, and the baking time is 10-15min.

[0026] Preferably, the thickness of the epoxy glass fiber prepreg and the epoxy carbon fiber prepreg is 0.2±0.02mm, and the surface layer is formed after hot pressing the laminated molding at a hot pressing temperature of 170℃ for 2h.

[0027] Preferably, the surface layer and the non-woven fabric layer are bonded by a two-component polyurethane adhesive, and the adhesive amount of the single surface layer is 110-120g / m 3 , the pressure of the roller coater is 2MPA, and the cold pressing time is 6h.

[0028] Preferably, 0.5-1.0% of the organic carboxylic acid salt nucleating agent by mass of the PP particles is further added in step S1, and the organic carboxylic acid salt nucleating agent and the PP particles are injected into the extruder after dry mixing.

[0029] Preferably, the organic carboxylic acid salt nucleating agent and the PP particles are added with adhesive oil in the form of atomization spraying during dry mixing, and the organic carboxylic acid salt nucleating agent is uniformly adhered to the PP particles by the adhesive oil.

[0030] Preferably, 5-7% of the high-density polyethylene particles HDPE by mass of the PP particles is further added in step S1, and the PP pipe reduces the hot melting temperature of the oven and the baking time after adding the high-density polyethylene particles.

[0031] Compared with the prior art, the beneficial effects of the present application are:

[0032] (1) The racket body was improved so that the improved racket body is made of several PP tubes with a diameter of 6-8mm, which are hot-melted to form a PP honeycomb core board with a honeycomb structure. The PP honeycomb core board is formed by hot-melting of simple PP tubes, and the diameter of the PP tubes is controlled between 6-8mm, while ensuring that the density of the PP honeycomb core board is 65-70kg / m³. 3 This process allows the compressive strength of the PP honeycomb core board to reach 1.2 MPa, resulting in higher compressive strength for Peak rackets with PP honeycomb cores. This ensures that even when Peak rackets are made with a thickness of 14mm or less, the handle of the PP honeycomb core board possesses sufficient compressive strength, reducing the likelihood of breakage. While maintaining the racket's overall shape, this process also significantly reduces the racket's weight, making PP honeycomb core Peak rackets lighter than other rackets. It also solves the problem of handle breakage in existing honeycomb core Peak rackets with thinner surfaces. Furthermore, it addresses the issues of high cost, heavy weight, and complex manufacturing processes associated with Peak rackets made primarily of carbon fiber or glass fiber.

[0033] (2) It effectively solves the problem that the handle of the racket made from the existing PP honeycomb board is prone to breakage when the thickness is relatively thin. At the same time, by controlling the screw temperature and speed in each section of the extruder, it solves the problem that the density of the honeycomb board is prone to fluctuate greatly during the production process, which leads to the breakage of the PP tube. This makes the PP tube more stable and less scrapped during the molding process.

[0034] (3) By controlling the temperature and time of the oven, the problem of PP pipes collapsing during the molding process due to their thin walls can be solved, thus improving the molding stability of honeycomb parts.

[0035] (4) By combining the non-woven honeycomb core with the surface layer to form the Peak racket, the elasticity of the Peak racket can be significantly improved, making it easier and less strenuous for users to hit the ball, with a longer service life. When athletes are exercising, they can hit the ball for a longer time, and their arms are less likely to become sore or their wrists injured during long-term use, making it safer. Attached Figure Description

[0036] Figure 1 This is a process flow diagram of the present invention;

[0037] Figure 2 This is a schematic diagram of the product structure of the present invention;

[0038] Figure 3 This is a schematic diagram of the PP honeycomb core panel in this invention;

[0039] In the figure: 1, surface layer; 11, glass fiber layer; 12, carbon fiber layer; 2, non-woven fabric layer; 3, racket body; 4, edge covering; 5, PP pipe; 6, PP honeycomb core plate; 7, POE film. DETAILED DESCRIPTION

[0040] The application will be further described below in conjunction with the drawings and specific embodiments. It should be noted that the embodiments described below or the technical features thereof can be combined with each other to form new embodiments without conflict.

[0041] In the description of the application, it should be understood that the terms "upper", "lower", "left", "right", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0042] The terms "first", "second", etc. in the application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally of a kind and do not limit the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the objects before and after are in an "or" relationship.

[0043] Embodiment 1

[0044] A PP honeycomb core pickleball racket, comprising a racket body 3, non-woven fabric layers 2 arranged on both sides of the racket body 3, a surface layer 1 arranged on the outer side of the non-woven fabric layer 2, and an edge covering 4 wrapped around the edges of the racket body 3. The racket body 3 is formed by a plurality of PP pipes 5 with a diameter of 6-8 mm, which are hot-melted to form a PP honeycomb core plate 6 with a honeycomb plate structure. The thickness of the PP honeycomb core plate 6 is 12-14 mm, and the density is 65-70 kg / m 3 The compression strength of the prepared PP honeycomb core plate 6 is ≥1.2 MPA.

[0045] Due to the unreasonable design of the PP pipe 5 and the incorrect raw material formula of the existing PP honeycomb plate material, the existing PP honeycomb plate made pickleball racket, although the overall weight is lighter than other materials, but due to its compression strength is generally around 0.8MPA, basically not more than 1MPA, when the racket body 3 is made, in order to ensure that the handle is not easy to break in the use process, it can only be compensated by increasing the thickness, increasing the density or shortening the length of the handle of the pickleball racket or increasing the auxiliary anti-breaking structure, which leads to the weight of the racket body 3 cannot be further reduced under the same conditions, and the research and development of the PP honeycomb core pickleball racket has produced a bottleneck for improvement, especially when the thickness of the racket body 3 is 10-14mm, it can only be compensated by increasing the density or shortening the length of the handle of the pickleball racket or increasing the auxiliary anti-breaking structure, which inevitably leads to the weight of the racket being increased again. In order to solve the problem that the existing PP honeycomb core structure of the pickleball racket reduces the overall weight and thickness while ensuring that the handle does not break, the racket body 3 is improved, so that the improved racket body 3 is formed by a plurality of PP pipes 5 with a diameter of 6-8mm hot melt into a honeycomb core plate 6, and the PP honeycomb core plate 6 is formed by hot melt of the PP pipe 5, and the diameter of the PP pipe 5 is controlled between 6-8mm, when the density of the PP honeycomb core plate 6 is 65-70kg / m 3 The compression strength of the PP honeycomb core plate 6 can reach 1.2MPA, the compression strength of the PP honeycomb core pickleball racket is higher, so that the handle of the PP honeycomb core plate 6 can have enough compression strength when the thickness of the pickleball racket is 14mm or less, so that the handle is not easy to break, the shape of the racket body 3 is not changed, the weight of the pickleball racket is further reduced, the weight of the PP material honeycomb core pickleball racket can be lighter than other rackets, and the problem of the existing honeycomb core pickleball racket that the handle is easy to break when the thickness is thin is solved, and the problem of the pickleball racket made of carbon fiber or glass fiber as the main skeleton material is high in cost, heavy in weight and complex in process is also solved.

[0046] Further improvement is that the PP pipe 5 is formed by hot melt extrusion of 1200HS PP particles, the diameter of the PP pipe 5 is 6mm, and the wall thickness is 0.15mm.

[0047] After continuous testing, it is found that when the main material of the PP pipe 5 is 1200HS PP particles formed by hot melt extrusion, the diameter of the PP pipe 5 is 6mm, and the wall thickness is 0.15mm, the density of the honeycomb part can reach 65kg / m 3The compression strength of the prepared PP honeycomb core plate 6 can reach about 1.2 MPA, and the bending strength of the 14 mm honeycomb core plate can reach about 25 MPA, so that the racket handle is less likely to be broken, the compression strength is better, the overall elasticity is better, the ball is easier to hit, and the problem that the racket handle and the racket are easily broken due to insufficient compression strength of the honeycomb core plate with a wall thickness of 10-14 mm during use can be effectively solved.

[0048] Further improvement is that the outer surface of the PP pipe 5 is covered with a POE adhesive film 7, and the adjacent two PP pipes 5 are fused and bonded by the POE adhesive film 7.

[0049] The POE adhesive film 7 can realize the bonding of the PP pipe 5 after hot melting, so that the honeycomb cuboid composed of the PP pipe 5 reaches the required compression strength, and the phenomenon of insufficient compression strength of the PP honeycomb core plate 6 is avoided; when the PP pipe 5 is cut, the honeycomb cuboid is placed on the electric heating wire hot cutting machine, and the honeycomb pipe plate material is cut to a certain thickness by using the electric heating wire hot cutting method, the thickness of the honeycomb pipe plate material is generally about 2 mm thicker than the PP honeycomb core plate 6, which can reserve enough leveling allowance for subsequent processing, and avoid the phenomenon that the thickness of the plate material does not meet the standard after forming. The honeycomb pipe plate material is used as the racket body 3, which greatly reduces the overall weight and increases the stability and compression performance. The vacuum forming process is used to realize the required diameter and wall thickness of the PP pipe 5, so that the PP pipe 5 combined in a honeycomb shape meets the compression strength requirements of the product after being combined to form a thermoplastic honeycomb core.

[0050] Further improvement based on the above embodiment is that the surface layer 1 includes a carbon fiber layer 12 and a glass fiber layer 11, and the surface layer 1 is attached to the non-woven fabric layer 2 through the glass fiber layer 11.

[0051] The pure carbon fiber is light in weight, but is not well bonded with the inner layer composite board. The surface layer 1 is composed of the carbon fiber layer 12 and the glass fiber layer 11. The hardness of the racket surface is ensured through the external carbon fiber layer 12, so that the racket has sufficient compressive strength. Meanwhile, the surface layer 1 is better bonded with the non-woven fabric layer 2 through the internal glass fiber layer 11, and the elasticity of the surface layer 1 is improved, so that the problems of the carbon fiber layer 12 not being easily bonded with the non-woven fabric layer 2, the glass fiber surface layer 1 having insufficient elasticity due to excessive hardness, and the glass fiber surface layer 1 having insufficient rigidity are solved. The process of the surface layer 1 is made the most simple and convenient, the overall weight is lighter, the racket is more portable when returning the ball, the elasticity is better, the compressive strength of the surface layer 1 is higher, the quality is lighter, and the appearance is good. Especially when the surface layer 1 is combined with the PP honeycomb core board 6, the elasticity of the racket for the ball is greatly improved through the increased elasticity of the surface layer 1 and the increased elasticity of the PP honeycomb core board 6, so that the elasticity of the racket in use is obviously improved compared with other rackets.

[0052] Further, the glass fiber layer 11 is composed of an epoxy glass fiber semi-cured sheet with a thickness of 0.2 mm, and the carbon fiber layer 12 is composed of an epoxy carbon fiber prepreg molding sheet with a thickness of 0.2 mm. The carbon fiber layer 12 and the glass fiber layer 11 are molded.

[0053] In order to avoid the problem of insufficient elasticity of the surface layer 1 during the returning process, the glass fiber layer and the carbon fiber layer 12 are improved. The thicknesses of the glass fiber layer and the carbon fiber layer 12 are designed in a ratio of 1:1, which can make the performance of the surface layer 1 more stable. Especially when the glass fiber layer 11 is composed of an epoxy glass fiber semi-cured sheet with a thickness of 0.2 mm, and the carbon fiber layer 12 is composed of an epoxy carbon fiber prepreg molding sheet with a thickness of 0.2 mm, and the two are molded, the thickness of the molded surface layer 1 is only 0.4 mm. The content of the glass fiber layer 11 is 60% of the total mass of the surface layer 1, which can make the weight of the entire pickleball racket lighter, effectively ensure the rigidity and rebound performance of the surface layer 1, make the elasticity of the PP honeycomb core board 6 also act on the ball, and compensate for the lack of elasticity of the surface layer 1 through the elasticity of the PP honeycomb core board 6, so that the pickleball racket achieves better rebound effect under the condition of a better surface layer 1.

[0054] The carbon fiber / glass fiber combined surface layer 1 with a thickness of about 0.4 mm can provide higher compressive strength to the entire pickleball racket, and the glass fiber layer 11 is better bonded with the non-woven fabric layer 2. The overall material is lighter, the appearance is good, and the elasticity is good through the surface carbon fiber layer 12.

[0055] Further improvement is that the non-woven fabric layer 2 is PET non-woven fabric, which is bonded with the racket body 3 and the surface layer 1 through PP non-woven fabric adhesive film, and the grammage ratio of the PET non-woven fabric and the PP non-woven fabric adhesive film is 2:1.

[0056] The non-woven fabric adopts PET non-woven fabric structure, has large tensile strength, large adhesive force between the honeycomb core and the non-woven fabric, large bending strength of the non-woven fabric honeycomb core, large compression strength in the tension state of the non-woven fabric, and can make the flatness of the composite surface layer 1 higher. At the same time, the combination of 2:1 PET non-woven fabric and PP non-woven fabric adhesive film can make the adhesive force between the PP honeycomb core plate 6 and the non-woven fabric larger, the bending strength of the combination of the non-woven fabric and the PP honeycomb core plate 6 larger, the non-woven fabric in the tension state, the compression strength of the PP honeycomb core plate 6 larger, and the flatness of the surface layer 1 better.

[0057] Embodiment 2:

[0058] A preparation method of a PP honeycomb core pickleball racket, the preparation method of the PP honeycomb core pickleball racket comprising

[0059] S1, the 1200HS PP particles and 8-10% POE particles of the mass of the PP particles are respectively extracted and injected into two plasticizing extruders for extrusion, and the two are co-extruded to form a PP tube 5 wrapped with a POE adhesive film 7 on the outside, the PP particle extruder contains seven interval temperatures, and the interval temperatures are 170, 180, 190, 208, 212, 215, and 215°C in turn, the temperature fluctuation is controlled within ±2°C, and the screw rotation speed is controlled at 605±1 rpm. The POE particle extruder contains five interval temperatures, and the interval temperatures are 224, 230, 235, 240, and 240°C respectively, the temperature fluctuation is controlled within ±2°C, and the screw rotation speed is controlled at 230±1 rpm. Then vacuum water cooling setting shape is carried out to form a PP tube 5 with an outer diameter of 6 mm and a thickness of about 0.15 mm, or a PP tube 5 with an outer diameter of 8 mm and a thickness of about 0.2 mm. The outside of the PP tube 5 is extruded by a POE extruder to form a POE adhesive film 7 with a thickness of about 0.01 mm;

[0060] S2, the PP tube 5 is cut to a certain length and arranged in a mold, and the POE adhesive film 7 is heated and melted in an oven to bond the PP tubes 5 to each other, the heating and melting temperature of the POE adhesive film 7 in the oven is 125°C, and the baking time is 12-15 min; after cooling, a honeycomb part with a density of 65-70 kg / m 3

[0061] ​S3, after hot cutting the honeycomb part, a PP honeycomb plate with a thickness of 12-16 mm is formed, the thickness of the PP honeycomb plate is about 2 mm thicker than the thickness of the PP honeycomb core plate 6, and then the two sides are leveled by polishing, so as to obtain the PP honeycomb core plate 6 with the required thickness, the honeycomb core density of the PP honeycomb core plate 6 is 65-70 kg / m 3 , the compressive strength is greater than or equal to 1.2 MP, wherein when the outer diameter of the PP pipe 5 is 6 mm and the thickness is 0.15 mm, the density of the obtained honeycomb part is 65 kg / m 3 , the compressive strength is about 1.2 MP;

[0062] S4, the PET non-woven fabric layer 2 is compounded to the two sides of the PP honeycomb core plate 6 by an adhesive to form a non-woven fabric honeycomb core;

[0063] S5, the glass fiber base cloth and the carbon fiber base cloth are pre-impregnated with epoxy resin to form epoxy glass fiber semi-cured sheet and epoxy carbon fiber pre-impregnated sheet, and the epoxy glass fiber semi-cured sheet and the epoxy carbon fiber pre-impregnated sheet are laminated and hot pressed to form the surface layer 1; the thickness of the epoxy glass fiber semi-cured sheet and the epoxy carbon fiber pre-impregnated sheet is 0.2±0.02 mm, and the surface layer 1 is formed after the laminated and hot pressed at a hot pressing temperature of 170℃ for 2h;

[0064] S6, the glass fiber base cloth on one side of the surface layer 1 is coated and cold pressed by a glue coating machine, and then the surface layer 1 is compounded to the surface of the non-woven fabric honeycomb core to form a pick racket plate; the surface layer 1 and the non-woven fabric layer 2 are bonded by using a two-component polyurethane adhesive, and the glue amount of the single surface layer 1 is 110-120 g / m 3 , the pressure of the roller coater is 2 MPA, and the cold pressing time is 6h;

[0065] S7, the pick racket plate is engraved to form a pick bare racket;

[0066] S8, the pick bare racket is UV printed, wrapped and edge wrapped to form a pick racket.

[0067] The PP honeycomb core plate 6 with a thickness of 10 / 12 / 14 mm prepared by the above method can have sufficient compressive strength, effectively solve the problem that the racket made of the existing PP honeycomb plate is prone to breakage at the handle when the thickness of the racket is relatively thin, and effectively solve the problem that the PP pipe 5 is prone to material breakage due to large density fluctuation during the production process of the honeycomb plate. The temperature and speed of the extruder can be controlled to solve the problem of material breakage of the PP pipe 5 due to large density fluctuation during the production process of the honeycomb plate, so that the stability of the PP pipe 5 during the forming process is better, and the scrap rate is lower. Especially when the racket made of the PP honeycomb core plate with a density of 65 kg / m3 is produced, the problem of large density fluctuation during the production process of the honeycomb plate by the conventional production process can be better solved, so that the PP pipe is prone to material breakage during the extrusion process of the extruder, and the forming stability of the PP pipe 5 is better. At the same time, by controlling the temperature and time of the oven, the problem of collapse during the forming process of the PP pipe 5 due to too thin wall thickness can be solved, and the forming stability of the honeycomb part is better. The surface layer 1 and the non-woven fabric layer 2 are bonded by using a two-component polyurethane adhesive. When the surface layer 1 is compounded to the PP honeycomb core plate 6 during the glue coating and cold pressing, a two-component polyurethane glue is used, the ratio of the glue and the curing agent is 4:1, the glue amount is 120 g / m2, the roll coating process is used, the glue amount is uniform and stable, the efficiency is high, the glue is put into the cold press after being coated, the cold pressing time is 6 h, and the pressure is 2 Mpa. The glue amount is small and uniform, the adhesive force is large, the two-component polyurethane can be uniformly coated, the adhesion is better after being bonded, the product flatness is good, the middle of the plate is a mirror stainless steel plate, and the surface of the plate is flat. After the non-woven fabric honeycomb core and the surface layer 1 are compounded, the elasticity of the racket is obviously improved, the user is more relaxed and labor-saving when playing the racket, the service life is longer, the player can play the racket for a longer time during the exercise, the arm is not prone to be soft or injured during the long use, and the safety is higher. When the racket plate compounded with the surface layer 1 is engraved into a naked racket, a vibrating knife is used for engraving, the obtained plate is placed on the engraving machine to obtain the racket, and the knife used is a vibrating knife without burrs, which is convenient for edge covering.

[0068] Example 3

[0069] On the basis of example 2, further improvement is made, that is, before the 1200HS PP particles are introduced into the extruder, 0.5-1.0% of the mass of the PP particles of an organic carboxylic acid salt nucleating agent is added, and the organic carboxylic acid salt nucleating agent and the PP particles are injected into the extruder after dry mixing.

[0070] The crystallization speed of the PP particles can be effectively induced, the crystallization temperature is increased, the bending strength of the PP pipe 5 is increased, the rigidity and hardness are increased, the bending strength of the PP pipe 5 is increased by 15-20%, the injection molding cycle is shortened by about 20%, the compression strength of the finally prepared PP honeycomb core board 6 reaches 1.3MPA, the compression strength of the pick racket is better, and the pick racket can be made lighter, wherein when 0.5% of the organic carboxylic acid salt nucleating agent of the mass of the PP particles is added, the compression strength of the finally prepared PP honeycomb core board 6 reaches about 1.3MPA, and the content of the organic carboxylic acid salt nucleating agent can be less while ensuring the compression strength.

[0071] Further improvement is that the organic carboxylic acid salt nucleating agent and the PP particles are added with adhesive oil in a spraying manner in the dry mixing process, and the adhesive oil is used to uniformly adhere the organic carboxylic acid salt nucleating agent to the PP particles.

[0072] In order to prevent the PP pipe 5 from delaminating or bridging after forming, the adhesive oil is added in a spraying manner in the dry mixing process, the adhesive oil is white oil, and the adhesive oil in the spraying manner can be better mixed with the powdered organic carboxylic acid salt nucleating agent, thereby helping the powdered organic carboxylic acid salt nucleating agent to be uniformly adhered to the PP particles.

[0073] Example 4:

[0074] Further improvement based on example 3 is that the organic carboxylic acid salt nucleating agent is added while 5-7% of the high-density polyethylene particles HDPE of the mass of the PP particles is added, the heat melting temperature of the oven for the PP pipe 5 is 123℃, and the baking time is 10-12min; and the density of the honeycomb part obtained after cooling is 65-70kg / m 3 The oven heat melting temperature and the baking time of the PP pipe 5 are reduced after the high-density polyethylene particles are added.

[0075] The compression strength of the honeycomb core board with a thickness of 14mm and a density of 65kg / m 3 obtained by examples 2-4 and the oven process parameters are shown in Table 1:

[0076] Table 1

[0077]

[0078] Through continuous testing of the PP pipe 5 made of different materials in the manufacture of honeycomb core boards with the same thickness, it is found that the ordinary PP particles currently used in the manufacture of 14mm thick and 65kg / m 3When PP pipe 5 is placed in the oven for baking at 125℃ / 10min, the honeycomb core plate is often prone to partial collapse during baking in the oven, and the compression strength of the prepared honeycomb core plate is generally around 0.8MPA. When PP pipe 5 formed by combining 1200HS particles and POE is placed in the oven for baking at 125℃ / 10min, the honeycomb core plate does not collapse during baking in the oven, and the compression strength of the prepared honeycomb core plate is generally around 1.2MPA. When PP pipe 5 formed by combining 1200HS particles with 0.5% nucleating agent is placed in the oven for baking at 125℃ / 10min, the honeycomb core plate does not collapse during baking in the oven, and the compression strength of the prepared honeycomb core plate is increased by about 0.1MPA compared to before adding the nucleating agent. Thus, the compression strength of the honeycomb core plate is better, especially when 0.5% nucleating agent and 5% HDPE are added to the 1200HS particles. After adding a certain amount of high-density polyethylene particles to PP pipe 5, PP pipe 5 can be formed after baking at 123℃ for 10min. This not only ensures that the compression strength of the prepared honeycomb core plate can reach about 1.3MPA, but also enables the bonding strength between adjacent PP pipes 5 to reach about 120N*mm / mm, greatly reducing the possibility of the handle directly breaking, thereby making the badminton racket safer. Compared to other formulations of PP pipe 5, the heating temperature of the oven is reduced by 2℃ during hot melt bonding in the oven process, and the time is also shortened by at least 2min. In the case of ensuring that PP does not collapse, reducing the oven hot melt temperature and baking time while improving the bonding performance makes the secure performance better, the production cost is lower during production, and the production efficiency is higher.

[0079] The above embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. Any non-essential changes and substitutions made by those skilled in the art based on the present application are within the scope of the present application.

Claims

1. A method of making a PP honeycomb cored Pickleball paddle, characterized by: The PP honeycomb core pickleball racket comprises a racket body (3), a non-woven fabric layer (2) arranged on both sides of the racket body (3), a surface layer (1) arranged on the outer side of the non-woven fabric layer (2), and a binding (4) wrapped around the edges of the racket body (3), and the preparation method of the PP honeycomb core pickleball racket comprises S1, 1200HS PP particles and POE particles are respectively extracted and injected into two extruders for plastic extrusion, and the two are co-extruded to form a PP tube (5) wrapped with a POE film (7) on the outside, and then vacuum water cooling is performed to form a PP tube (5) with an outer diameter of 6-8mm and a thickness of 0.15-0.2mm, and the thickness of the POE film (7) of the PP tube (5) is 0.01mm; S2, the PP tube (5) is cut to a certain length and arranged in a mold, and the POE film (7) is heated and melted in an oven to bond the PP tubes (5) to each other, and a honeycomb part is obtained after cooling; S3, the honeycomb part is hot cut and formed to obtain a PP honeycomb core plate (6) with a required thickness, and the density of the honeycomb core of the PP honeycomb core plate (6) is 65-70kg / m³, and the compressive strength is ≥1.2MP; S4, the non-woven fabric layer (2) is compounded on both sides of the PP honeycomb core plate (6) to form a non-woven fabric honeycomb core; S5, glass fiber base cloth and carbon fiber base cloth are pre-impregnated with epoxy resin to form epoxy glass fiber semi-solid sheet and epoxy carbon fiber prepreg sheet, and the epoxy glass fiber semi-solid sheet and the epoxy carbon fiber prepreg sheet are laminated and hot pressed to form a surface layer (1); S6, the glass fiber base cloth on one side of the surface layer (1) is coated and cold pressed by a glue coating machine, and then the surface layer (1) is compounded on the surface of the non-woven fabric honeycomb core to form a pickleball plate; S7, the pickleball plate is engraved to form a pickleball bare racket; S8, the pickleball bare racket is UV printed and wrapped with a binding (4) to form a pickleball racket.

2. A method of making a PP honeycomb cored Pickleball paddle according to claim 1, wherein: The PP particle extruder contains seven interval temperatures, and the interval temperatures are 170, 180, 190, 208, 212, 215, and 215℃ respectively, the temperature fluctuation is controlled within ±2℃, and the screw rotation speed is controlled at 605±1rpm. The POE particle extruder contains five interval temperatures, and the interval temperatures are 224, 230, 235, 240, and 240℃ respectively, the temperature fluctuation is controlled within ±2℃, and the screw rotation speed is controlled at 230±1rpm. ​ 3. A process for the preparation of a PP honeycomb cored Paddle Ball racket as claimed in claim 2, wherein: In step S1, 0.5-1.0% of the mass of the PP particles of an organic carboxylic acid salt nucleating agent is also added, and the organic carboxylic acid salt nucleating agent and the PP particles are injected into the extruder after dry mixing.

4. A process for making a PP honeycomb cored Paddle Ball racket as claimed in claim 3, wherein: In step S1, 5-7% of the mass of the PP particles of high-density polyethylene particles HDPE is also added, and the PP tube (5) is lowered in oven hot melting temperature and baking time after adding the high-density polyethylene particles HDPE.

5. A method for preparing a PP honeycomb core peak racket according to any one of claims 1 to 4, characterized in that: The surface layer (1) comprises a carbon fiber layer (12) and a glass fiber layer (11), and the surface layer (1) is attached to the non-woven fabric layer (2) through the glass fiber layer (11).

6. A method of making a PP honeycomb cored Paddle Ball racket as claimed in claim 5, wherein: The glass fiber layer (11) is composed of an epoxy glass fiber semi-cured sheet with a thickness of 0.2 mm, the carbon fiber layer (12) is composed of an epoxy carbon fiber prepreg molding sheet with a thickness of 0.2 mm, and the carbon fiber layer (12) and the glass fiber layer (11) are molded.

7. A method of making a PP honeycomb cored Paddle Ball racket as claimed in claim 6, wherein: The non-woven fabric layer (2) is PET non-woven fabric, the PET non-woven fabric is bonded with the racket main body (3) and the surface layer (1) through a PP non-woven fabric adhesive film, and the grammage ratio of the PET non-woven fabric and the PP non-woven fabric adhesive film is 2:1.

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