A carbon fiber-containing paper pot and a method for manufacturing and using the same

Abstract

This invention discloses a carbon fiber-containing paper cone, its preparation method, and its application. The carbon fiber-containing paper cone of this invention, by weight, comprises the following components: 30-50 parts bleached sulfate wood pulp, 10-30 parts Manila hemp pulp, 10-30 parts cotton pulp, 10-30 parts carbon fiber, and 5-30 parts polyvinyl alcohol fiber. The preparation method of the carbon fiber-containing paper cone of this invention is simple and convenient. The resulting carbon fiber-containing paper cone has the characteristics of low density and high modulus. Increasing the amount of carbon fiber added improves the bonding performance between carbon fiber and other fibers while retaining the mechanical properties of carbon fiber. When applied to loudspeakers, it can expand the speaker's vibration frequency and simultaneously achieve a higher sound pressure level.

Description

Technical Field

[0001] This invention relates to the field of loudspeaker technology, and more particularly to a carbon fiber-containing paper cone, its preparation method, and its application. Background Technology

[0002] The paper cone is a key component of a loudspeaker system, and its performance largely determines the loudspeaker's effective frequency range, distortion performance, and sound quality. Traditional paper cones use plant fibers as raw materials, but paper cones made from plant fibers have drawbacks such as insufficient rigidity. Carbon fiber, as an emerging material, has advantages such as high strength, high Young's modulus, and lightweight, making it suitable for the preparation of paper cone materials.

[0003] The strength of carbon fiber paper cones is influenced by both fiber strength and interfiber bonding. While carbon fiber possesses advantages such as high strength and high modulus, its fiber surface is smooth and lacks functional groups. In carbon fiber paper cones prepared using the wet papermaking process, the carbon fibers cannot form hydrogen bonds with plant fibers. The weak bonding between carbon fibers and plant fibers means that the amount of carbon fiber added to the paper cone material should not be too high. Adding a small amount of carbon fiber (≤15%) can increase the rigidity of the paper cone; however, further increasing the amount of carbon fiber will result in very weak fiber bonding and a significant decrease in the strength of the paper cone.

[0004] CN1124907A discloses a novel planar conductive heating carbon fiber composite paper material and its preparation method. This composite paper uses carbon fiber as the conductive phase and cellulose pulp as the matrix. The process involves cutting long carbon fiber filaments into shorter pieces, dispersing them in an aqueous phase with a dispersant, and then mixing them with uniformly dispersed cellulose, followed by conventional papermaking processes. This invention's conductive heating composite paper is lightweight, small in size, provides uniform heat dissipation, is safe, has high thermal efficiency, and is widely applicable. It can be widely used in industrial or household applications to achieve heating, insulation, and thermal insulation purposes. This invention uses carbon fiber and cellulose pulp to form paper via a wet process. The conductive heating paper uses carbon fiber as the conductive phase for heating. The determining factors for the conductive heating paper include the carbon fiber itself and the bonding force between the carbon fiber and the matrix. However, in this type of carbon fiber paper, the weak bonding force between the carbon fiber and the matrix, coupled with a low carbon fiber content, results in poor heating performance.

[0005] CN111676733A discloses a method for preparing carbon fiber paper and its application. The effective components and weight parts of the carbon fiber paper are as follows: 40-50 parts of long-fiber paulownia pulp; 20-30 parts of short-fiber ayous pulp; 2-8 parts of sisal fiber; 5-12 parts of carbon fiber; 1-3 parts of kapok; 1-3 parts of Manila hemp; 1-2 parts of urea-formaldehyde resin; and 8-12 parts of wool. The invention describes the preparation of carbon fiber paper using the above raw materials, and the use of the resulting carbon fiber paper in the preparation of loudspeaker diaphragms. This invention effectively solves the problems of delamination and uneven weight distribution in paper diaphragms, and features a Young's modulus as high as 4G, and a sound propagation speed twice that of traditional paper diaphragms. The method involves first preparing a pulp from seven fibers: long-fiber pumice wood pulp, short-fiber ayous wood pulp, carbon fiber, sisal fiber, kapok, Manila hemp pulp, and wool. This pulp is then wet-formed and dried to form a base paper. Next, a layer of thermosetting resin is coated onto the base paper to bond it into carbon fiber paper. Finally, the carbon fiber paper is soaked in water and hot-pressed into paper basins. This method of preparing paper basins is relatively complex, and the post-processing time for the carbon fiber paper is also long. Furthermore, due to the poor ductility of carbon fiber paper, there is a risk of breakage during hot pressing. Therefore, the carbon fiber paper prepared by this method is only suitable for the preparation of certain types of paper basins and lacks universal applicability.

[0006] CN111876995A discloses a method for modifying carbon fiber for paper and its application. The specific steps of the modification method are: mixing carbon fiber with dilute sulfuric acid for acidification treatment; compounding the acidified carbon fiber with a cationic surfactant to obtain modified carbon fiber A; compounding modified carbon fiber A with anionic surfactant to obtain modified carbon fiber; resulting in a high-performance modified carbon fiber with excellent surface activity, low electrical resistance, and good mechanical properties, meeting the requirements for high-performance carbon fiber paper production and application. This method uses dilute sulfuric acid to modify the surface of carbon fiber, and then uses electrostatic interaction to compound anionic and cationic surfactants on the carbon fiber surface, improving the bonding force between fibers. This method modifies the surface of carbon fiber, which to some extent damages the carbon fiber structure, leading to a decrease in carbon fiber performance. At the same time, the carbon fiber processing steps are relatively cumbersome, requiring multiple impregnation and drying processes, with long impregnation times, which is not conducive to industrial production.

[0007] To improve the surface activity of carbon fibers, CN110172819B discloses a method for preparing amphiphilic carbon fibers. This method mainly involves liquid-phase oxidation of carbon fibers to increase the functional groups on the carbon fiber surface. After oxidation with chromic acid solution, grafting treatment is performed on the carbon fiber surface to impart hydrophilic and oleophilic groups, thus achieving the production of amphiphilic carbon fibers. However, this method uses oxidation to corrode the carbon fiber surface, which can also damage the carbon fiber structure and reduce its mechanical properties.

[0008] CN105568459A discloses an antistatic polyvinyl alcohol fiber, comprising: polyvinyl alcohol fiber, plant fiber, animal fiber, and conductive carbon fiber. The polyvinyl alcohol fiber accounts for 32%-50% of the mass percentage of the antistatic polyvinyl alcohol fiber, the plant fiber accounts for 13%-18% of the mass percentage, the animal fiber accounts for 10%-15% of the mass percentage, and the conductive carbon fiber accounts for 27%-35% of the mass percentage. This invention enables the polyvinyl alcohol fiber to possess the advantage of being antistatic; however, the bonding strength between the carbon fiber and the plant fiber needs further improvement.

[0009] In summary, how to enhance the bonding force between carbon fiber and plant fiber to increase the upper limit of carbon fiber addition in paper basins has become an urgent problem to be solved. Therefore, developing a simple process that can improve the bonding performance of carbon fiber with other fibers while retaining the mechanical properties of carbon fiber is the focus of research in this field. Summary of the Invention

[0010] To address the shortcomings of existing technologies, the present invention aims to provide a carbon fiber-containing paper cone, its preparation method, and its application. The carbon fiber-containing paper cone of the present invention has the characteristics of low density and high modulus, and increases the amount of carbon fiber added. While retaining the mechanical properties of carbon fiber, it improves the bonding performance of carbon fiber with other fibers. When applied to loudspeakers, it can expand the vibration frequency of the loudspeaker and simultaneously output a higher sound pressure level.

[0011] One of the objectives of this invention is to provide a paper basin containing carbon fiber. To achieve this objective, the invention adopts the following technical solution:

[0012] A paper basin containing carbon fiber, comprising the following components by weight:

[0013]

[0014] This invention adds PVA in fibrous form to pulp, increasing the upper limit of carbon fiber addition in the paper cone pulp, raising the maximum carbon fiber addition to 30%, thereby improving the mechanical properties of the paper cone. The resulting paper cone has the characteristics of low density and high modulus. When applied to loudspeakers, it can expand the vibration frequency of the loudspeaker and at the same time output a higher sound pressure level.

[0015] Specifically, a paper basin containing carbon fiber comprises the following components by weight:

[0016] The weight fraction of bleached sulfate wood pulp is 30-50 parts, for example, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49 or 50 parts, etc.

[0017] The weight of Manila hemp pulp is 10-30 parts, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts, etc.

[0018] The weight of the cotton pulp is 10-30 parts, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts, etc.

[0019] The carbon fiber has a weight percentage of 10-30 parts, for example, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 parts, etc.

[0020] The weight percentage of polyvinyl alcohol fiber is 5-30 parts, for example, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, 21 parts, 22 parts, 23 parts, 24 parts, 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, or 30 parts, etc.

[0021] In this invention, the polyvinyl alcohol fiber is a water-soluble polyvinyl alcohol fiber. When used in papermaking, polyvinyl alcohol fiber acts as an adhesive rich in hydroxyl groups, enabling it to form hydrogen bonds with plant fibers. Simultaneously, during the heating process, the polyvinyl alcohol fiber acts as a binder between carbon fibers and plant fibers, increasing the bonding strength between them and improving the mechanical properties of the paperboard.

[0022] In this invention, the length of the polyvinyl alcohol fiber is 5-8 mm, for example, 5 mm, 6 mm, 7 mm, 8 mm, etc.

[0023] In this invention, the water solubility temperature of the polyvinyl alcohol fiber is 80-95℃, for example, 80℃, 81℃, 82℃, 83℃, 84℃, 85℃, 86℃, 87℃, 88℃, 89℃, 90℃, 91℃, 92℃, 93℃, 94℃, 95℃, etc.

[0024] In this invention, the length of the carbon fiber is 5-8mm, for example, 5mm, 6mm, 7mm, 8mm, etc.

[0025] A second objective of this invention is to provide a method for preparing a paper basin containing carbon fiber, comprising the following steps:

[0026] (1) Mix bleached sulfate wood pulp, Manila hemp pulp and cotton pulp according to the formula and beat them to obtain component A; mix carbon fiber and polyvinyl alcohol fiber according to the formula and stir to obtain component B;

[0027] (2) After mixing component A and component B obtained in step (1), add water to dilute to a slurry concentration of 0.2-0.8% and stir to disperse it evenly. Filter it on a paper basin forming mold to obtain a paper basin blank.

[0028] (3) The paper basin blank obtained in step (2) is hot-pressed to obtain a paper basin blank;

[0029] (4) The paper basin blank obtained in step (3) is punched to obtain the paper basin containing carbon fiber.

[0030] The preparation method of the carbon fiber paper basin of the present invention is simple and convenient. It only requires mixing water-soluble polyvinyl alcohol directly with paper pulp in fibrous form to form the carbon fiber paper basin. No additional processes such as impregnation or coating are required. At the same time, the preparation method of the present invention avoids the performance degradation caused by the destruction of carbon fiber structure.

[0031] In step (1), the beating degree of the pulp is 15-40°SR, for example, beating degrees of 15°SR, 16°SR, 17°SR, 18°SR, 19°SR, 20°SR, 21°SR, 22°SR, 23°SR, 24°SR, 25°SR, 26°SR, 27°SR, 28°SR, 29°SR, 30°SR, 31°SR, 32°SR, 33°SR, 34°SR, 35°SR, 36°SR, 37°SR, 38°SR, 39°SR or 40°SR, etc.

[0032] In step (3), the hot pressing temperature is 100-250℃, for example, 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃ or 250℃, and the hot pressing time is 20-40s, for example, 20s, 21s, 22s, 23s, 24s, 25s, 26s, 27s, 28s, 29s, 30s, 31s, 32s, 33s, 34s, 35s, 36s, 37s, 38s, 39s, 40s, etc.

[0033] As a preferred embodiment of the present invention, the method for preparing the carbon fiber-containing paper basin includes the following steps:

[0034] (1) Mix the three pulps, namely bleached sulfate wood pulp, Manila hemp pulp and cotton pulp, according to the formula and beat them to a freeness of 15-40°SR to obtain component A; add carbon fiber and polyvinyl alcohol fiber to water according to the formula and stir to obtain component B;

[0035] (2) After mixing component A and component B obtained in step (1), add water to dilute to a slurry concentration of 0.2-0.8% and stir to disperse it evenly. Filter it on a paper basin forming mold to obtain a paper basin blank.

[0036] (3) The paper basin blank obtained in step (2) is hot-pressed at a temperature of 100-250℃ for 20-40s to obtain a paper basin blank.

[0037] (4) The paper basin blank obtained in step (3) is punched to obtain the paper basin containing carbon fiber.

[0038] A third objective of this invention is to provide an application of the carbon fiber-containing paper cone described in one objective, using the carbon fiber-containing paper cone in the manufacture of a loudspeaker.

[0039] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0040] The carbon fiber-containing paper cone of this invention features low density and high modulus. It increases the amount of carbon fiber added, with a maximum addition of 30%. While retaining the mechanical properties of carbon fiber, it improves the bonding performance between carbon fiber and other fibers. When applied to loudspeakers, it can expand the loudspeaker's vibration frequency and simultaneously achieve a higher sound pressure level. Specifically, the density of the resulting paper cone is 0.68-0.82 g / cm³. 3 The Young's modulus is 4.21-4.99 GPa, and the tensile strength is 27.74-36.13 KN / m. Detailed Implementation

[0041] The technical solution of the present invention will be further illustrated below through specific embodiments.

[0042] Unless otherwise specified, all raw materials used in this invention are commercially available or can be prepared using conventional methods in the art.

[0043] The raw materials for each component in the following examples are sourced as follows: bleached sulfate wood pulp (BKP, purchased from Guangzhou Yunqi Electroacoustic Technology Development Co., Ltd.), Manila hemp pulp (purchased from Guangzhou Yunqi Electroacoustic Technology Development Co., Ltd.), cotton pulp (purchased from Guangzhou Yunqi Electroacoustic Technology Development Co., Ltd.), carbon fiber (polyacrylonitrile-based chopped carbon fiber, purchased from Guangzhou Yunqi Electroacoustic Technology Development Co., Ltd., length 6mm, brand: Toray Industries, Japan), and water-soluble polyvinyl alcohol fiber (purchased from Yong'an Baohualin Industrial Development Co., Ltd., length 6mm, dissolution temperature 85℃).

[0044] Example 1

[0045] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight: 50 parts bleached sulfate wood pulp, 10 parts Manila hemp pulp, 10 parts cotton pulp, 30 parts carbon fiber, and 15 parts water-soluble polyvinyl alcohol fiber.

[0046] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0047] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0048] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0049] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0050] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0051] Example 2

[0052] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight fraction: 30 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 30 parts carbon fiber, and 15 parts water-soluble polyvinyl alcohol fiber.

[0053] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0054] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0055] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0056] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0057] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0058] Example 3

[0059] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight: 30 parts bleached sulfate wood pulp, 30 parts Manila hemp pulp, 30 parts cotton pulp, 10 parts carbon fiber, and 5 parts water-soluble polyvinyl alcohol fiber.

[0060] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0061] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0062] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0063] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 200℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0064] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0065] Example 4

[0066] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight: 40 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 20 parts carbon fiber, and 30 parts water-soluble polyvinyl alcohol fiber.

[0067] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0068] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0069] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0070] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 250℃ and the hot pressing time is 20s to obtain the paper basin blank.

[0071] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0072] Example 5

[0073] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight: 50 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 10 parts carbon fiber, and 5 parts water-soluble polyvinyl alcohol fiber.

[0074] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0075] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0076] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0077] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 100℃ and the hot pressing time is 40s to obtain the paper basin blank.

[0078] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0079] Example 6

[0080] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight: 40 parts bleached sulfate wood pulp, 30 parts Manila hemp pulp, 15 parts cotton pulp, 15 parts carbon fiber, and 20 parts water-soluble polyvinyl alcohol fiber.

[0081] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0082] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0083] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0084] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 220℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0085] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0086] Example 7

[0087] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight: 30 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 30 parts carbon fiber, and 30 parts water-soluble polyvinyl alcohol fiber.

[0088] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0089] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0090] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0091] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0092] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0093] Example 8

[0094] This embodiment provides a carbon fiber-containing speaker cone. The raw materials for preparing the carbon fiber-containing speaker cone include the following components by weight fraction: 30 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 30 parts 4mm carbon fiber, and 15 parts water-soluble polyvinyl alcohol fiber.

[0095] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0096] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0097] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0098] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0099] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0100] Example 9

[0101] This embodiment provides a carbon fiber-containing speaker cone. The raw materials for preparing the carbon fiber-containing speaker cone include the following components by weight fraction: 30 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 30 parts 2mm carbon fiber, and 15 parts water-soluble polyvinyl alcohol fiber.

[0102] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0103] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0104] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0105] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0106] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0107] Example 10

[0108] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight fraction: 30 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 30 parts carbon fiber, and 15 parts water-soluble polyvinyl alcohol fiber dissolved at 70°C.

[0109] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0110] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0111] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0112] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0113] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0114] Example 11

[0115] This embodiment provides a speaker cone containing carbon fiber. The raw materials for preparing the speaker cone containing carbon fiber include the following components by weight fraction: 30 parts bleached sulfate wood pulp, 20 parts Manila hemp pulp, 20 parts cotton pulp, 30 parts carbon fiber, and 15 parts 3mm dissolved water-soluble polyvinyl alcohol fiber.

[0116] The carbon fiber-containing paper basin in this embodiment is prepared by the following method:

[0117] (1) Mix the three plant fibers according to the above ratio and pulp them to obtain component A with a freeness of 30°SR; add carbon fiber and polyvinyl alcohol fiber to water and stir to obtain component B;

[0118] (2) Mix component A and component B, dilute with water, disperse, and filter to obtain paper basin blanks;

[0119] (3) Place the paper basin blank obtained in step (2) into a high-temperature mold for hot pressing. The hot pressing temperature is 180℃ and the hot pressing time is 30s to obtain the paper basin blank.

[0120] (4) The central hole and edge material of the paper cone blank obtained in step (3) are removed by using a punching tool to obtain the paper cone for the loudspeaker containing carbon fiber.

[0121] Comparative Example 1

[0122] This comparative example provides a speaker cone, which differs from Example 2 in that the carbon fiber content is increased to 35 parts. The increased carbon fiber is deducted from other components on average to ensure that the total amount remains unchanged. The preparation method is the same as in Example 2.

[0123] Comparative Example 2

[0124] This comparative example provides a paper cone for a loudspeaker. The difference from Example 2 is that the carbon fiber content is reduced to 5 parts, and the reduced carbon fiber is added to other components on average to ensure that the total amount remains unchanged. The content of other components and the preparation method are the same as in Example 2.

[0125] Comparative Example 3

[0126] This comparative example provides a paper cone for a loudspeaker, which differs from Example 2 in that the hot-pressing temperature is 80°C, while the content of other components and the preparation method are the same as in Example 2.

[0127] Comparative Example 4

[0128] This comparative example provides a paper cone for a loudspeaker, which differs from Example 2 in that the hot-pressing temperature is 280°C, while the content of other components and the preparation method are the same as in Example 2.

[0129] Comparative Example 5

[0130] This comparative example provides a speaker cone, which differs from Example 2 in that the hot-pressing time is 10 seconds, while the content of other components and the preparation method are the same as in Example 2.

[0131] Comparative Example 6

[0132] This comparative example provides a speaker cone, which differs from Example 2 in that the hot-pressing time is 50 seconds, while the content of other components and the preparation method are the same as in Example 2.

[0133] Comparative Example 7

[0134] This comparative example provides a paper cone for a loudspeaker, which differs from Example 2 in that aramid fiber is used instead of carbon fiber, while the content of other components and the preparation method are the same as in Example 2.

[0135] Comparative Example 8

[0136] This comparative example provides a speaker cone, which differs from Example 2 in that PE fiber is used instead of water-soluble polyvinyl alcohol fiber, while the content of other components and the preparation method are the same as in Example 2.

[0137] Comparative Example 9

[0138] This comparative example provides a speaker cone that differs from Example 2 in that it does not contain water-soluble polyvinyl alcohol fiber. The reduced amount of water-soluble polyvinyl alcohol fiber is added to other components to ensure that the total amount remains unchanged. The preparation method is the same as in Example 2.

[0139] Comparative Example 10

[0140] This comparative example provides a speaker cone, which differs from Example 2 in that the amount of water-soluble polyvinyl alcohol fiber added is reduced to 2 parts, and the reduced water-soluble polyvinyl alcohol fiber is added to other components on average. The preparation method is the same as in Example 2.

[0141] Comparative Example 11

[0142] This comparative example provides a speaker cone, which differs from Example 2 in that the amount of water-soluble polyvinyl alcohol fiber added is increased to 40 parts. The increased amount of water-soluble polyvinyl alcohol fiber is deducted from other components on average to ensure that the total amount remains unchanged. The preparation method is the same as in Example 2.

[0143] Comparative Example 12

[0144] This comparative example provides a speaker cone, which differs from Example 2 only in that the water-soluble polyvinyl alcohol fiber is first dissolved in hot water and then mixed with the pulp in the form of a solution. The content of other components and the preparation method are the same as in Example 2.

[0145] Performance testing

[0146] Performance tests were conducted on 0.5 mm thick paperboards produced using the same process as the paper cones in Examples 1-7 and Comparative Examples 1-12. The method for testing Young's modulus was referenced from "Development of Device for Young's Modulus and Loss Factor of Loudspeaker Diaphragm". The tensile strength was tested according to the national standard GB / T 12914-2018 "Determination of Tensile Strength of Paper and Paperboard - Constant Speed ​​Tensile Test (20 mm / min)" and was performed on a tensile strength tester (L&W CE062, Sweden).

[0147] Table 1

[0148]

[0149]

[0150] As shown in Table 1, the density of the carbon fiber paperboard prepared by the method described in this invention is 0.68-0.82 g / cm³. 3 The Young's modulus is 4.21-4.99 GPa and the tensile strength is 27.74-36.13 KN / m, indicating that the addition of water-soluble polyvinyl alcohol fiber in this invention can play a role in bonding carbon fiber and bleached sulfate wood pulp, improving the poor bonding force between carbon fiber and other fibers, increasing the carbon fiber content, and improving the modulus of the paper cone.

[0151] In Examples 8 and 9, carbon fibers of different lengths were used, and their properties were roughly the same. The tensile strength of carbon fibers with reduced lengths was relatively weaker than that of 6mm fibers.

[0152] Examples 9-10 use different water-soluble polyvinyl alcohol fibers. The melting temperature of the polyvinyl alcohol fibers is lower than the hot-pressing temperature, and the fiber length and melting temperature do not have a significant impact on the performance of the paper cone.

[0153] A comparison of the results of Example 2 and Comparative Example 1 shows that an excessive increase in carbon fiber can also lead to a decrease in the performance of the paper cone. Too much carbon fiber results in weaker bonding between fibers, leading to a decrease in the modulus of the paper cone.

[0154] A comparison of the results of Example 2 and Comparative Example 2 shows that if the amount of carbon fiber added is too small, the effect on improving the strength of the paper cone will not be obvious.

[0155] In Comparative Example 3, the hot-pressing temperature was too low, and the paper basin could not be formed.

[0156] In Comparative Example 4, the hot pressing temperature was too high, causing the water-soluble fibers in the paper blank to dissolve too quickly. As the moisture evaporated, the water-soluble fibers migrated to the surface of the paper cone, resulting in the water-soluble fibers not acting on the bonding between the carbon fibers and wood pulp fibers inside the paper cone, thus reducing the modulus and tensile strength.

[0157] In Comparative Example 5, the hot pressing time was too short, and the water-soluble polyvinyl alcohol fiber did not have enough time to dissolve, thus failing to exert its effect of enhancing fiber bonding.

[0158] In Comparative Example 6, if the hot pressing time is too long, the paper cone becomes brittle. At this time, although the paper cone has a high Young's modulus, its tensile strength decreases significantly.

[0159] A comparison of the results of Example 2 and Comparative Example 7 shows that the Young's modulus of the paper cone decreased after aramid fiber was used to replace carbon fiber, indicating that the reinforcing effect of aramid fiber on the paper cone is not as good as that of carbon fiber.

[0160] A comparison of the results of Example 2 and Comparative Example 8 shows that when PE fiber is used to replace water-soluble polyvinyl alcohol fiber, the PE does not melt and flow sufficiently during the hot pressing process and fails to disperse evenly in the paper tray, resulting in its performance being lower than that of polyvinyl alcohol fiber.

[0161] The results of Example 2, Comparative Example 9, and Comparative Example 10 show that when no water-soluble polyvinyl alcohol fiber is added or the amount of water-soluble polyvinyl alcohol fiber added is small, the bonding force between carbon fiber and wood pulp is poor, resulting in a significant decrease in its modulus and tensile strength.

[0162] The results of Example 2 and Comparative Example 11 show that when too much water-soluble polyvinyl alcohol fiber is added, the Young's modulus of the paper cone will decrease, but the tensile strength of the paper cone will increase.

[0163] A structural comparison between Example 2 and Comparative Example 12 shows that the water-soluble polyvinyl alcohol (PVA) fiber is first dissolved in water and then mixed with plant fibers in solution form. During the paper basin green water molding process, some of the PVA fiber solution is lost with the water. Compared with the preparation method described in this invention, the water-soluble PVA fiber does not achieve optimal results; therefore, the Young's modulus and tensile strength of the paper basin both show a downward trend.

[0164] This invention illustrates the detailed process equipment and process flow through the above embodiments. However, this invention is not limited to the detailed process equipment and process flow described above, meaning that this invention does not necessarily depend on the detailed process equipment and process flow to be implemented. Those skilled in the art should understand that any improvements to this invention, equivalent substitutions of raw materials for the product of this invention, addition of auxiliary components, and selection of specific methods, all fall within the protection scope and disclosure scope of this invention.

[0165] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0166] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0167] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A paper basin containing carbon fiber, characterized in that, By weight, it contains the following components: 30-50 parts of bleached sulfate wood pulp 10-30 portions of Manila hemp pulp 10-30 parts cotton pulp 10-30 parts carbon fiber 5-30 parts of polyvinyl alcohol fiber; The polyvinyl alcohol fiber is a water-soluble polyvinyl alcohol fiber; The polyvinyl alcohol fiber has a length of 5-8 mm.

2. The paper basin containing carbon fiber according to claim 1, characterized in that, The water solubility temperature of the polyvinyl alcohol fiber is 80-95℃.

3. The paper basin containing carbon fiber according to claim 1, characterized in that, The length of the carbon fiber is 5-8 mm.

4. A method for preparing a carbon fiber-containing paper basin as described in any one of claims 1-3, characterized in that, Includes the following steps: (1) Mix the three pulps, namely bleached sulfate wood pulp, Manila hemp pulp and cotton pulp, according to the ratio and beat them to obtain component A; mix carbon fiber and polyvinyl alcohol fiber according to the ratio and stir to obtain component B; (2) After mixing component A and component B obtained in step (1), add water to dilute to a slurry concentration of 0.2-0.8% and stir to disperse it evenly. Filter it on a paper basin forming mold to obtain a paper basin blank. (3) The paper basin blank obtained in step (2) is hot-pressed to obtain a paper basin blank; (4) The paper basin blank obtained in step (3) is punched to obtain the paper basin containing carbon fiber.

5. The preparation method according to claim 4, characterized in that, In step (1), the beating degree of the pulp is 15-40°SR.

6. The preparation method according to claim 4, characterized in that, In step (3), the hot pressing temperature is 100-250℃ and the hot pressing time is 20-40s.

7. The preparation method according to claim 4, characterized in that, Includes the following steps: (1) Mix the three pulps, namely bleached sulfate wood pulp, Manila hemp pulp and cotton pulp, according to the formula and beat them to a freeness of 15-40°SR to obtain component A; add carbon fiber and polyvinyl alcohol fiber to water according to the formula and stir to obtain component B; (2) After mixing component A and component B obtained in step (1), add water to dilute to a slurry concentration of 0.2-0.8% and stir to disperse it evenly. Filter it on a paper basin forming mold to obtain a paper basin blank. (3) The paper basin blank obtained in step (2) is hot-pressed at a temperature of 100-250℃ for 20-40s to obtain a paper basin blank. (4) The paper basin blank obtained in step (3) is punched to obtain the paper basin containing carbon fiber.

8. An application of a carbon fiber-containing paper basin as described in any one of claims 1-3, characterized in that, The carbon fiber-containing paper cone is used in the manufacture of a loudspeaker.

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