Preparation method of composite carbon-carbon heat-preservation hard felt and composite carbon-carbon heat-preservation hard felt prepared by same

Abstract

The invention provides a preparation method of a composite carbon-carbon heat-preservation hard felt and the composite carbon-carbon heat-preservation hard felt prepared by the preparation method, and relates to the technical field of carbon fiber heat-preservation materials. The preparation method comprises the following steps: preparation of the soft felt, preparation of the reinforcing layer, preparation of the composite layer of the buffer layer and the reinforcing layer, preparation of the carbon-carbon heat preservation felt matrix, preparation of the composite carbon-carbon heat preservation felt and preparation of the composite carbon-carbon heat preservation hard felt. The composite carbon-carbon thermal-insulation hard felt prepared by the method has good impact resistance, bending resistance, scouring resistance and low porosity, the resistance of the carbon-carbon thermal-insulation hard felt to high-speed airflow scouring and erosion in the use process is greatly enhanced, and the service life of the product is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of carbon fiber thermal insulation materials, and in particular to a method for preparing a composite carbon-carbon thermal insulation hard felt and the composite carbon-carbon thermal insulation hard felt prepared thereby. Background Art

[0002] At present, the general density of carbon-carbon thermal insulation felt is 0.18~0.21g / cm 3 The porosity is between 88 and 89.7%, and the thermal conductivity is between 0.2 and 0.4 W / mk. The performance parameters of the thermal insulation performance of carbon-carbon thermal insulation hard felt are reflected in the thermal conductivity. The lower the thermal conductivity of carbon-carbon thermal insulation hard felt, the better the thermal insulation performance. Carbon-carbon thermal insulation hard felt with lower thermal conductivity will have a correspondingly larger porosity. In a high-temperature, furnace-pressure use environment, the carbon-carbon thermal insulation felt with high porosity on the surface is infiltrated and deposited by product steam, causing the density of the carbon-carbon thermal insulation hard felt to increase and the thermal insulation performance to decrease. Because the carbon filaments inside the carbon-carbon thermal insulation felt are affected by steam erosion for a long time, the carbon-carbon thermal insulation felt will eventually be delaminated and voided, affecting the service life of the carbon-carbon thermal insulation felt. In addition, the current production process of traditional carbon-carbon thermal insulation hard felt is: carbon fiber short cutting - carding - web forming - needle punching reinforcement - soft felt compounding - cutting and preparation - hot pressing of layering - carbonization - high temperature - finished product, that is, it is mostly made of pre-oxidized integral felt, and its reinforcement method is overall needle punching molding, and the internal fibers are distributed in three-dimensional disorder.

[0003] If the gas contains elements such as silicon, after use, such elements will penetrate into the carbon-carbon insulation felt under the pressure in the furnace, and deposit and react on the surface of the carbon filaments inside the carbon-carbon insulation felt. The abnormal reaction and deposition of carbon-carbon insulation felt products during use will cause the density of low-density carbon-carbon insulation felt to increase passively, reduce internal porosity, and reduce insulation performance. The difference in density between the inside and outside of the insulation felt caused by abnormal deposition will lead to different linear expansion coefficients between the inside and outside of the insulation felt under high temperature conditions, which will eventually lead to delamination and shedding of the carbon-carbon insulation felt.

[0004] On the other hand, the carbon fibers and char in the carbon-carbon thermal insulation felt react with the ambient gas in the furnace at high temperature, causing chemical corrosion of the ambient gas on the carbon-carbon thermal insulation felt, reducing the structural strength of the entanglement points of the mutually entangled fibers formed by the overall needle punching reinforcement and the strength of the carbon fibers in the carbon-carbon thermal insulation felt, resulting in powdering and stratification abnormalities in the product.

[0005] If the carbon-carbon thermal insulation product is used in an environment where nitrogen, argon and other elements are the main components, the high-speed flow of gas will cause high-speed erosion on the fiber entanglement points on the surface of the carbon-carbon thermal insulation felt formed by overall needle punching. After long-term use, the fiber entanglement points inside the carbon-carbon thermal insulation felt will be damaged, eventually causing damage to the carbon-carbon thermal insulation felt structure.

[0006] In view of this, the present invention is proposed. Summary of the invention

[0007] The purpose of the present invention is to provide a method for preparing a composite carbon-carbon thermal insulation felt and a composite carbon-carbon thermal insulation felt prepared thereby. The present invention provides a method for preparing a carbon fiber thermal insulation felt that is resistant to erosion, corrosion and has a long service life under high temperature and furnace pressure conditions, and is used to improve the problem of insufficient service life of conventional common carbon fiber thermal insulation felt under high temperature and high pressure conditions.

[0008] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are particularly adopted:

[0009] In a first aspect, the present invention provides a method for preparing a composite carbon-carbon thermal insulation hard felt, the preparation method comprising:

[0010] Preparation of soft felt: Short-cut carbon fiber filaments are opened and meshed to obtain a carbon fiber mesh; the carbon fiber mesh is stacked in a Z-shaped reciprocating manner and then reinforced by needle punching to obtain a surface density of 800 to 1300 g / m 2 of soft felt;

[0011] Preparation of the reinforcement layer: The short chopped carbon fiber filaments are opened and needled to obtain a surface density of 150-250g / m 2 A reinforcing layer mesh; applying a phenolic resin liquid with a carbon content of 40 to 45% to the surface of the single-piece reinforcing layer mesh, and then applying a phenolic resin powder with a residual carbon content of 55 to 60%; stacking and curing and pressing the single-piece mesh after applying the phenolic resin twice to obtain a reinforcing layer;

[0012] Preparation of composite layer: Surface density is 1100~1300g / m 2 A phenolic resin liquid with a residual carbon rate of 46-50% is applied to the surface of the soft felt to cover the reinforcing layer, and the composite layer of the buffer layer and the reinforcing layer is obtained after curing;

[0013] Preparation of carbon-carbon thermal insulation felt matrix: single sheet surface density is 800-1100g / m 2 Applying phenolic resin liquid with a residual carbon rate of 30-35% on both sides of the soft felt, and then applying phenolic resin liquid with a residual carbon rate of 46-50% after curing; stacking and curing and pressing the single soft felt after applying the phenolic resin to obtain a carbon-carbon thermal insulation felt matrix;

[0014] Preparation of composite carbon-carbon thermal insulation felt: applying phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the carbon-carbon thermal insulation felt substrate, covering the composite layer, and curing to obtain the composite carbon-carbon thermal insulation felt;

[0015] Preparation of composite carbon-carbon thermal insulation hard felt: the composite carbon-carbon thermal insulation felt is carbonized and subjected to high-temperature treatment to obtain the composite carbon-carbon thermal insulation hard felt.

[0016] Preferably, in the preparation process of the soft felt, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm.

[0017] Preferably, in the mixed chopped carbon filaments: the chopped carbon filaments with a length of less than 60 mm account for less than 50 wt %, and the chopped carbon filaments with a length of more than 100 mm account for ≥ 10 wt %.

[0018] Preferably, in the preparation process of the soft felt, the opening step comprises: stirring the chopped carbon fiber filaments to obtain preliminary mixed carbon filaments; and opening the preliminary mixed carbon filaments through a multi-roller opening machine to obtain mixed carbon filaments.

[0019] Preferably, in the opening step of preparing the soft felt, the stirring speed is 65-75 rpm, and the stirring time is 3-5 min; the parameters of the multi-roller opening machine include: 4-8 pairs of opening rollers, the frequency of the opening rollers is 10-20 Hz, and the frequency of the cylinder is 40-50 Hz.

[0020] Preferably, in the preparation process of the soft felt, the web-forming step includes: sending the mixed carbon filaments obtained by opening into a cotton box via a high-speed airflow to form fiber balls, combing them via a high-speed cylinder to form a fiber web, and stripping them from the high-speed cylinder via negative pressure adsorption to obtain a carbon fiber web.

[0021] Preferably, in the web-forming step of preparing the soft felt, the rotation speed of the high-speed cylinder is 1200-1300 rpm; the negative pressure adsorption is provided by fans on both sides, and the frequency of the fans is 30-40 Hz.

[0022] Preferably, in the preparation process of the soft felt, when the surface density of the soft felt is 1100-1300 g / m 2 When the number of layers of the reciprocating stacking is 22 to 26, the density of the needle punching reinforcement is 15 to 25 needles / cm 2 .

[0023] Preferably, in the preparation process of the soft felt, when the surface density of the soft felt is 800-1100 g / m 2 When the number of layers of the reciprocating stacking is 16 to 22 layers, the density of the needle punching reinforcement is 15 to 25 needles / cm 2 .

[0024] Preferably, in the process of preparing the reinforcement layer, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm.

[0025] Preferably, in the process of preparing the reinforcement layer, the opening step comprises: opening and combing the chopped carbon fiber filaments through a roller carding machine to obtain mixed carbon filaments.

[0026] Preferably, in the opening step of preparing the reinforcement layer, the parameters of the roller carding machine include: 6 to 8 groups of working rollers, the linear speed of the working rollers is 50 to 70 m / min, and the linear speed of the cylinder is 1100 to 1200 m / min.

[0027] Preferably, in the process of preparing the reinforcing layer, the needling step comprises: needling the mixed carbon filaments obtained by opening to obtain a carbon fiber having a surface density of 150 to 250 g / m 2 Reinforcement layer mesh tire.

[0028] Preferably, in the needling step of preparing the reinforcing layer, the needling density is 10 to 15 needles / cm 2 .

[0029] Preferably, in the process of preparing the reinforcing layer, the step of applying the phenolic resin liquid with a carbon content of 40-45% comprises: spraying the surface of the single-piece reinforcing layer web and then letting it stand.

[0030] Preferably, in the step of preparing the reinforcing layer by applying a phenolic resin liquid with a carbon content of 40-45%, the viscosity of the phenolic resin liquid is less than 1000 cps; and the spraying material-liquid ratio is 1:(1.4-1.6).

[0031] Preferably, in the step of preparing the reinforcing layer by applying a phenolic resin solution having a carbon content of 40 to 45%, the standing time is 0.5 to 2 hours.

[0032] Preferably, during the preparation of the reinforcing layer, the step of applying phenolic resin powder with a residual carbon rate of 55-60% includes: under vibration conditions, applying phenolic resin liquid on one side of the surface of the reinforcing layer mesh, and then applying phenolic resin powder with a residual carbon rate of 55-60%.

[0033] Preferably, in the step of applying phenolic resin powder with a residual carbon rate of 55-60% to prepare the reinforcement layer, the frequency of the vibration is 13-18 Hz; and the applied material-to-powder ratio is 1:(0.6-0.8).

[0034] Preferably, during the preparation of the reinforcement layer, the number of stacked layers is 4 to 10.

[0035] Preferably, during the preparation of the reinforcement layer, the temperature of the curing and pressing is 170-180° C., and the compression ratio of the curing and pressing is ≥6.5.

[0036] Preferably, in the process of preparing the composite layer, the step of applying the phenolic resin liquid with a residual carbon rate of 46-50% comprises: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to a surface density of 1100-1300g / m2 Soft felt surface.

[0037] Preferably, in the process of preparing the composite layer, the thickness of the soft felt is ≥15 mm and the density is ≤0.085 g / cm 3 ; The viscosity of the phenolic resin liquid is ≥10000cps; The amount of the applied glue is 240-260g / m 2 ;

[0038] Preferably, during the preparation of the composite layer, the curing temperature is 210-230°C.

[0039] Preferably, in the process of preparing the carbon-carbon thermal insulation felt matrix, the step of applying the phenolic resin liquid with a residual carbon rate of 30-35% comprises: using a glue spraying device to apply the phenolic resin liquid with a residual carbon rate of 30-35% to a surface density of 800-1100 g / m 2 Soft felt on both sides.

[0040] Preferably, in the process of preparing the carbon-carbon thermal insulation felt matrix, the thickness of the soft felt is ≥10 mm and the density is ≤0.090 g / cm 3 ; The viscosity of the phenolic resin liquid is ≤400cps; the applied material-liquid ratio is 1:(2.4~2.6).

[0041] Preferably, during the preparation of the carbon-carbon thermal insulation felt matrix, the curing temperature is 210-230°C.

[0042] Preferably, in the preparation process of the carbon-carbon thermal insulation felt matrix, the step of applying phenolic resin liquid with a residual carbon rate of 46-50% includes: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the soft felt.

[0043] Preferably, in the step of applying a phenolic resin liquid with a residual carbon rate of 46-50% to prepare the carbon-carbon thermal insulation felt matrix, the viscosity of the phenolic resin liquid is ≥10000cps; the amount of the applied glue spray is 240-260g / m 2 .

[0044] Preferably, during the preparation of the carbon-carbon thermal insulation felt matrix, the number of stacked layers is 5 to 65.

[0045] Preferably, during the preparation of the carbon-carbon thermal insulation felt matrix, the temperature of the curing and pressing is 210-230° C., and the compression ratio of the curing and pressing is (1.15-1.3):1.

[0046] Preferably, in the preparation process of the composite carbon-carbon thermal insulation felt, the step of applying phenolic resin liquid with a residual carbon rate of 46-50% includes: using a pneumatic spray gun to apply phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the carbon-carbon thermal insulation felt substrate.

[0047] Preferably, in the step of applying a phenolic resin liquid with a residual carbon rate of 46-50% to prepare the composite carbon-carbon thermal insulation felt, the viscosity of the phenolic resin liquid is ≥10000cps; the amount of the applied glue spray is 240-260g / m 2 .

[0048] Preferably, during the preparation of the composite carbon-carbon thermal insulation felt, the curing temperature is 210-230°C.

[0049] Preferably, the carbonization procedure includes:

[0050] A protective gas is introduced into the carbonization furnace, and the temperature begins to rise after 3 to 5 hours. The corresponding process curve is set, and the total time is 29 to 30 hours to heat up to 940 to 960°C, and then the temperature is kept at 940 to 960°C for 4 to 6 hours, and then the temperature is lowered to 60 to 80°C to stop carbonization.

[0051] Preferably, the high temperature treatment procedure includes:

[0052] The high-temperature furnace is evacuated to a vacuum degree below -0.1Mpa, protective gas is introduced, and the corresponding process curve is set. It takes a total of 48 to 52 hours to heat up to 2250-2350°C, and then the temperature is kept at 2250-2350°C for 18 to 22 hours. Subsequently, the temperature is lowered to 60-80°C to stop the high-temperature treatment.

[0053] In a second aspect, the present invention provides a composite carbon-carbon thermal insulation hard felt, which comprises a reinforcing layer, a buffer layer and a carbon-carbon thermal insulation hard felt matrix stacked in sequence; and the composite carbon-carbon thermal insulation hard felt is prepared by the preparation method of the composite carbon-carbon thermal insulation hard felt described in the first aspect.

[0054] Preferably, the thickness of the reinforcement layer is 1 to 6.5 mm, the thickness of the buffer layer is 5 to 15 mm, and the thickness of the carbon-carbon thermal insulation hard felt matrix is ​​20 to 300 mm.

[0055] Preferably, the density of the reinforcement layer is 1.35-1.45 g / cm 3 The density of the buffer layer is 0.080~0.085g / cm 3 The density of carbon-carbon thermal insulation felt matrix is ​​0.15~0.17g / cm 3 .

[0056] Preferably, the porosity of the reinforcement layer is 15-20%, the porosity of the buffer layer is 95-96%, and the porosity of the carbon-carbon thermal insulation hard felt matrix is ​​90-92%.

[0057] Preferably, the thermal conductivity of the buffer layer is 0.05-0.10 W / mk, and the thermal conductivity of the carbon-carbon thermal insulation hard felt matrix is ​​0.17-0.25 W / mk.

[0058] Compared with the prior art, the present invention has the following beneficial effects:

[0059] (1) The surface of the carbon-carbon thermal insulation felt of the present invention has a high-density reinforcement layer structure, and has good impact resistance, bending resistance, scour resistance, and low porosity, which greatly enhances the carbon-carbon thermal insulation felt's ability to resist scour and erosion by high-speed airflow during use, thereby extending the product's service life.

[0060] (2) The carbon-carbon thermal insulation hard felt described in the present invention is provided with a low-density buffer layer between the reinforcement layer and the carbon-carbon thermal insulation hard felt matrix. The structure has high porosity, high specific surface area, high thermal insulation performance and elasticity. The thermal conductivity of the layer is only 0.1W / mk. The low thermal conductivity has good high temperature impact resistance. During use, the difference in linear expansion coefficient between the surface reinforcement layer and the carbon-carbon thermal insulation hard felt matrix caused by high temperature can be buffered and deformed, thereby reducing the probability of abnormal stratification caused by the difference in linear expansion coefficient during product use.

[0061] (3) The low-density buffer layer of the carbon-carbon thermal insulation hard felt described in the present invention has a high specific surface area and good adsorption performance for corrosive and reactive gases. It can effectively adsorb the corrosive and reactive gases that penetrate into the carbon-carbon thermal insulation hard felt matrix through the reinforcement layer during use, thereby protecting the carbon-carbon thermal insulation hard felt matrix and extending the service life of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0063] Figure 1 It is a schematic structural diagram of the composite carbon-carbon thermal insulation hard felt of the present invention.

[0064] Among them, 1 is a reinforcement layer, 2 is a buffer layer, and 3 is a carbon-carbon thermal insulation hard felt matrix. DETAILED DESCRIPTION

[0065] Unless otherwise defined herein, scientific and technological terms used in conjunction with the present invention shall have the meanings commonly understood by those of ordinary skill in the art. The meaning and scope of the terms should be clear, however, in the case of any potential ambiguity, the definitions provided herein take precedence over any dictionary or external definitions. In this application, unless otherwise stated, the use of "or" means "and / or". In addition, the use of the term "including" and other forms is non-limiting.

[0066] It should be noted that specific details are described in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways different from those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0067] The embodiments of the present invention will be described in detail below in conjunction with the embodiments and examples, but it will be appreciated by those skilled in the art that the following embodiments and examples are only used to illustrate the present invention and should not be considered as limiting the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention. If specific conditions are not specified, proceed according to normal conditions or conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0068] In a first aspect, the present invention provides a method for preparing a composite carbon-carbon thermal insulation hard felt, the preparation method comprising:

[0069] Preparation of soft felt: Short-cut carbon fiber filaments are opened and meshed to obtain a carbon fiber mesh; the carbon fiber mesh is stacked in a Z-shaped reciprocating manner and then reinforced by needle punching to obtain a surface density of 800 to 1300 g / m 2 of soft felt;

[0070] Preparation of the reinforcement layer: The short chopped carbon fiber filaments are opened and needled to obtain a surface density of 150-250g / m 2 A reinforcing layer mesh; applying a phenolic resin liquid with a carbon content of 40 to 45% to the surface of the single-piece reinforcing layer mesh, and then applying a phenolic resin powder with a residual carbon content of 55 to 60%; stacking and curing and pressing the single-piece mesh after applying the phenolic resin twice to obtain a reinforcing layer;

[0071] Preparation of composite layer: Surface density is 1100~1300g / m 2 A phenolic resin liquid with a residual carbon rate of 46-50% is applied to the surface of the soft felt to cover the reinforcing layer, and the composite layer of the buffer layer and the reinforcing layer is obtained after curing;

[0072] Preparation of carbon-carbon thermal insulation felt matrix: single sheet surface density is 800-1100g / m 2 Applying phenolic resin liquid with a residual carbon rate of 30-35% on both sides of the soft felt, and then applying phenolic resin liquid with a residual carbon rate of 46-50% after curing; stacking and curing and pressing the single soft felt after applying the phenolic resin to obtain a carbon-carbon thermal insulation felt matrix;

[0073] Preparation of composite carbon-carbon thermal insulation felt: applying phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the carbon-carbon thermal insulation felt substrate, covering the composite layer, and curing to obtain the composite carbon-carbon thermal insulation felt;

[0074] Preparation of composite carbon-carbon thermal insulation hard felt: the composite carbon-carbon thermal insulation felt is carbonized and subjected to high-temperature treatment to obtain the composite carbon-carbon thermal insulation hard felt.

[0075] In the present invention, the preparation process of carbon-carbon thermal insulation hard felt is: carbon fiber short cutting - opening - netting - composite reinforcement (after reinforcement, it can be cut and prepared) - reinforcement layer pressing - buffer layer shaping - spray glue curing - hot pressing of layers - hot pressing composite - carbonization - high temperature - finished product. The preparation method obtains a carbon fiber thermal insulation hard felt that is resistant to erosion, corrosion and has a long service life under high temperature and furnace pressure environment, which is used to improve the problem of insufficient service life of traditional ordinary carbon fiber thermal insulation hard felt under high temperature and high pressure conditions.

[0076] It should be noted that the key point of the present invention is a new type of carbon-carbon thermal insulation hard felt product with a composite structure. A high-density anti-scour reinforcement layer and a low-density, high specific surface area buffer layer are added to the surface of the traditional carbon-carbon thermal insulation hard felt in the form of high-temperature composite, which greatly improves the service life of the carbon-carbon thermal insulation hard felt under special working conditions such as high temperature, high-speed airflow scour, and corrosive steam. The comprehensive service life can reach more than 6 times that of traditional carbon-carbon thermal insulation hard felt. The new carbon-carbon thermal insulation hard felt adopts a multi-layer composite structure of a high-density reinforcement layer, a low-density buffer layer, and a carbon-carbon thermal insulation hard felt matrix. Among them, the production of the high-density reinforcement layer uses a mass ratio of phenolic resin to mesh tire, parameter control during the curing and pressing process, and a composite form of multi-layer mesh tire stacking without needle puncture. The production of the low-density buffer layer uses a mass ratio of phenolic resin to soft felt, and parameter control during the curing and pressing process. Furthermore, the present invention further improves the service life of the carbon-carbon thermal insulation hard felt under high temperature and high pressure conditions by means of a step-by-step composite processing method and composite process parameter control of the carbon-carbon thermal insulation hard felt substrate, the high-density reinforcement layer, and the low-density buffer layer.

[0077] As an optional embodiment, during the preparation of the soft felt, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm (for example, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, etc.).

[0078] As an optional embodiment, in the mixed chopped carbon filaments: the chopped carbon filaments with a length of less than 60 mm account for less than 50wt% (for example, it can be 45wt%, 40wt%, 35wt%, 30wt%, 25wt%, 20wt%, 15wt%, 10wt%, 5wt%, 1wt%, 0wt%, etc.), and the chopped carbon filaments with a length of more than 100 mm account for ≥10wt% (for example, it can be 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, 45wt%, 50wt%, 55wt%, etc.).

[0079] As a preferred embodiment, during the preparation of the soft felt, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm.

[0080] As an optional embodiment, in the preparation process of the soft felt, the opening step includes: stirring the chopped carbon fiber filaments to obtain preliminary mixed carbon filaments; and opening the preliminary mixed carbon filaments through a multi-roller opening machine to obtain mixed carbon filaments.

[0081] It should be noted that the above-mentioned opening specifically includes: putting short carbon filaments of different lengths into a stirring container, and achieving preliminary mixing of short carbon filaments of different lengths by mechanical stirring. Pour the mixed carbon filaments that have completed preliminary mixing onto the transmission curtain of the bag opener, and feed them into the multi-roller opener through the metal impurity remover to achieve opening and mixing of the short carbon filaments.

[0082] As an optional embodiment, in the opening step of preparing the soft felt, the stirring speed is 65-75rpm (for example, it can be 65rpm, 66rpm, 68rpm, 70rpm, 72rpm, 74rpm, 75rpm, etc.), and the stirring time is 3-5min (for example, it can be 3min, 3.5min, 4min, 4.5min, 5min, etc.); the parameters of the multi-roller opener include: 4-8 pairs of opening rollers (for example, it can be 4 pairs, 6 pairs, 8 pairs, etc.), the frequency of the opening rollers is 10-20Hz (for example, it can be 10Hz, 12Hz, 14Hz, 16Hz, 18Hz, 20Hz, etc.), and the frequency of the cylinder is 40-50Hz (for example, it can be 40Hz, 42Hz, 44Hz, 46Hz, 48Hz, 50Hz, etc.).

[0083] It should be noted that in the opening step of preparing the soft felt, the present invention controls the mixing speed and time to achieve preliminary mixing of chopped carbon filaments of different lengths, which is convenient for subsequent opening; further, by setting the logarithm of the multi-roller opening rollers, it is better to avoid excessive tensile force on the carbon fiber, reduce damage to the carbon fiber, and make the tension of the carbon fiber in the opening process more uniform, so as to better avoid breakage problems caused by uneven tension; at the same time, the frequency of the opening rollers and the frequency of the cylinder in the opening machine are set, so that the force distribution in the opening process is relatively smooth, and the integrity and length of the fiber can be better maintained.

[0084] As an optional embodiment, in the preparation process of the soft felt, the web forming step includes: sending the mixed carbon filaments obtained by opening into a cotton box via a high-speed airflow to form fiber balls, combing them through a high-speed cylinder to form a fiber web, and stripping them from the high-speed cylinder through negative pressure adsorption to obtain a carbon fiber web.

[0085] It should be noted that the above-mentioned web formation specifically includes: the fibers are opened by a multi-roller opener and then sent into a cotton box through a high-speed airflow, and the opened fiber clusters are lifted upward by the conveying nail curtain to the cotton-evening roller and the cotton-dropping roller. The fiber clusters are uniformed and measured by the cotton-evening roller, and then stripped off by the cotton-dropping roller and transferred to the vibration plate. The vibration of the vibration plate drives the fiber clusters to fall and evenly stack on the conveying leather curtain to form continuous fiber clusters. The continuous fiber clusters are accurately measured by a precise metering device and then sent into the high-speed cylinder by the feeding roller. The cylinder combs the fiber clusters at high speed to form a fiber web, and the fiber web is adsorbed by the breathable curtain with negative pressure and stripped off from the high-speed cylinder. Subsequently, the carbon fiber web is sent into the reciprocating web laying curtain through the conveying curtain for reciprocating laying.

[0086] As an optional embodiment, in the web-forming step of preparing the soft felt, the rotation speed of the high-speed cylinder is 1200-1300rpm (for example, it can be 1200rpm, 1220rpm, 1240rpm, 1250rpm, 1260rpm, 1280rpm, 1300rpm, etc.); the negative pressure adsorption is provided by fans on both sides, and the frequency of the fans is 30-40Hz (for example, it can be 30Hz, 32Hz, 34Hz, 35Hz, 36Hz, 38Hz, 40Hz, etc.).

[0087] It should be noted that in the above-mentioned web-forming process, the fiber clusters are combed by a high-speed cylinder to form a fiber web, and the fiber web is adsorbed by a breathable curtain with negative pressure and stripped more completely from the high-speed cylinder to form a highly disordered, isotropic, continuous carbon fiber web with a certain strength.

[0088] As an optional embodiment, during the preparation of the soft felt, the carbon fiber mesh is stacked in a Z-shaped reciprocating manner and then reinforced by needle punching to obtain a surface density of 800 to 1300 g / m2 (For example, it can be 800g / m 2 , 850g / m 2 , 900g / m 2 , 950g / m 2 1000g / m 2 , 1050g / m 2 , 1100g / m 2 , 1150g / m 2 , 1200g / m 2 , 1250g / m 2 , 1300g / m 2 etc.) of soft felt.

[0089] It should be noted that the carbon fiber mesh is laid back and forth in a "Z" shape according to the parameter setting values ​​after passing through the feeding curtain, annular curtain, reciprocating curtain, and output clamping roller of the reciprocating paving machine in sequence. The surface density required by the product design is set by setting the process parameters of the paving layer number of the paving machine, that is, the surface density of the soft felt is adjusted by the paving layer number. Furthermore, multiple pre-needling machines with needle plate arrangements such as upper puncture, lower puncture, and upper and lower puncture are used to repeatedly needle-punch and reinforce the fiber mesh that has been completed and stacked, and finally a surface density of 800-1300g / m is obtained. 2 Soft felt, that is, carbon-carbon thermal insulation hard felt embryo with different surface density ranges.

[0090] As an optional embodiment, during the preparation of the soft felt, when the surface density of the soft felt is 1100-1300 g / m 2 For example, it can be 1100g / m 2 , 1150g / m 2 , 1200g / m 2 , 1250g / m 2 , 1300g / m 2 The number of layers of the reciprocating stacking is 22 to 26 layers, for example, 22 layers, 23 layers, 24 layers, 25 layers, 26 layers, and the density of the needle punching reinforcement is 15 to 25 needles / cm 2 , for example, 15 needles / cm 2 , 16 needles / cm 2 , 17 needles / cm 2 , 18 needles / cm 2 , 19 needles / cm 2 , 20 needles / cm 2 , 21 needles / cm 2 , 22 needles / cm 2 , 23 needles / cm 2 , 24 needles / cm 2 , 25 needles / cm 2 wait.

[0091] As an optional embodiment, during the preparation of the soft felt, when the surface density of the soft felt is 800 to 1100 g / m 2 For example, it can be 800g / m 2 , 850g / m 2 , 900g / m 2 , 950g / m 2 1000g / m 2 , 1050g / m 2 , 1080g / m 2 The number of layers of the reciprocating stacking is 16 to 22 layers, for example, 16 layers, 17 layers, 18 layers, 19 layers, 20 layers, 21 layers, 22 layers, and the density of the needle punching reinforcement is 15 to 25 needles / cm 2 , for example, 15 needles / cm 2 , 16 needles / cm 2 , 17 needles / cm 2 , 18 needles / cm 2 , 19 needles / cm 2 , 20 needles / cm 2 , 21 needles / cm 2 , 22 needles / cm 2 , 23 needles / cm 2 , 24 needles / cm 2 , 25 needles / cm 2 wait.

[0092] As an optional embodiment, during the preparation of the soft felt, the surface density obtained by needle punching is 800 to 1300 g / m 2 The soft felt can also go through the cutting and preparation steps, that is, the reinforced soft felt is cut to size according to the blank specifications of the product, and the number of soft felt sheets required for the carbon-carbon thermal insulation felt is prepared based on weight and thickness.

[0093] As an optional embodiment, during the preparation of the reinforcement layer, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm (for example, 40 mm, 50 mm, 60 mm, 70 mm, 80 mm, 90 mm, 100 mm, 110 mm, 120 mm, etc.).

[0094] As an optional embodiment, during the preparation of the reinforcement layer, the opening step includes: opening and combing the chopped carbon fiber filaments through a roller carding machine to obtain mixed carbon filaments.

[0095] As an optional embodiment, in the opening step of preparing the reinforcement layer, the parameters of the roller carding machine include: 6 to 8 groups of working rollers (for example, 6 groups, 7 groups, or 8 groups), the linear speed of the working rollers is 50 to 70 m / min (for example, 50 m / min, 52 m / min, 54 m / min, 55 m / min, 56 m / min, 58 m / min, 60 m / min, 62 m / min, 64 m / min, 66 m / min, 68 m / min, 70 m / min, etc.), and the linear speed of the cylinder is 1100 to 1200 m / min (for example, 1100 m / min, 1120 m / min, 1140 m / min, 1150 m / min, 1160 m / min, 1180 m / min, 1200 m / min, etc.).

[0096] As an optional embodiment, in the process of preparing the reinforcing layer, the needling step includes: needling the mixed carbon filaments obtained by opening to obtain a surface density of 150 to 250 g / m 2 (For example, it can be 150g / m 2 , 160g / m 2 , 170g / m 2 , 180g / m 2 , 190g / m 2 , 200g / m 2 , 210g / m 2 , 220g / m 2 , 130g / m 2 , 240g / m 2 , 250g / m 2 etc.) of the reinforcement layer mesh tire.

[0097] As an optional embodiment, in the needling step of preparing the reinforcing layer, the needling density is 10 to 15 needles / cm 2 (For example, it can be 10 needles / cm 2 , 11 needles / cm 2 , 12 needles / cm 2 , 13 needles / cm 2 , 14 needles / cm 2 , 15 needles / cm 2 wait).

[0098] As an optional implementation, after the needling step of preparing the reinforcing layer, the finished reinforcing layer web can be cut into several pieces according to a preset reinforcing layer product density to complete the reinforcing layer web preparation.

[0099] As an optional embodiment, during the preparation of the reinforcement layer, the step of applying a phenolic resin liquid with a carbon content of 40-45% (for example, 40%, 41%, 42%, 43%, 44%, 45%, etc.) includes: spraying the surface of the single-piece reinforcement layer mesh and then letting it stand.

[0100] As an optional embodiment, in the step of preparing the phenolic resin liquid with a carbon application rate of 40-45% (for example, it can be 40%, 41%, 42%, 43%, 44%, 45%, etc.) for the reinforcement layer, the viscosity of the phenolic resin liquid is less than 1000cps (for example, it can be 990cps, 980cps, 960cps, 950cps, 940cps, 920cps, 900cps, 850cps, 800cps, 700cps, 600cps, 500cps, etc.); the material-liquid ratio of the spraying is 1:(1.4-1.6) (for example, it can be 1:1.4, 1:1.45, 1:1.5, 1:1.55, 1:1.6, etc.). [The above-mentioned phenolic resin liquid with a carbon application rate of 40-45% is referred to as phenolic resin liquid 1. ]

[0101] As an optional embodiment, in the step of applying a phenolic resin liquid with a carbon rate of 40-45% to prepare the reinforcement layer, the standing time is 0.5-2h (for example, it can be 0.5h, 0.6h, 0.7h, 0.8h, 0.9h, 1h, 1.2h, 1.4h, 1.5h, 1.6h, 1.8h, 2h, etc.).

[0102] As an optional embodiment, during the preparation of the reinforcement layer, the step of applying phenolic resin powder with a residual carbon rate of 55-60% includes: applying a phenolic resin liquid on one side of the surface of the reinforcement layer mesh under vibration, and then applying phenolic resin powder with a residual carbon rate of 55-60% (for example, 55%, 56%, 57%, 58%, 59%, 60%, etc.). [The above-mentioned phenolic resin powder with a carbon rate of 55-60% is referred to as phenolic resin powder 2. 】

[0103] As an optional embodiment, in the step of applying phenolic resin powder with a residual carbon rate of 55-60% to prepare the reinforcement layer, the frequency of the vibration is 13-18 Hz, for example, it can be 13 Hz, 14 Hz, 15 Hz, 16 Hz, 17 Hz, 18 Hz, etc.; the applied material-powder ratio is 1:(0.6-0.8) (for example, it can be 1:0.6, 1:0.65, 1:0.7, 1:0.75, 1:0.8, etc.).

[0104] As an optional implementation, during the preparation of the reinforcement layer, the number of stacked layers is 4 to 10.

[0105] As an optional embodiment, during the preparation of the reinforcement layer, the temperature of the curing pressing is 170-180°C (for example, it can be 170°C, 172°C, 174°C, 175°C, 176°C, 178°C, 180°C, etc.), and the compression ratio of the curing pressing is ≥6.5 (for example, it can be 6.5, 6.6, 6.7, 6.8, 6.9, 7.0, etc.).

[0106] As an optional embodiment, the method for preparing the reinforcement layer comprises the following steps:

[0107] A peristaltic pump and a resin spraying device with a gear pump are used to spray the surface of a single-layer reinforced mesh tire, and a phenolic resin liquid 1 with a viscosity of less than 1000cps and a residual carbon rate of 40-45% is applied. After spraying, the mesh tire is allowed to stand in a container with polytetrafluoroethylene. After standing, the container is transferred as a whole to a vibrating screen, and a phenolic resin powder 2 with a residual carbon rate of 55-60% is applied to the surface of the mesh tire sprayed with the phenolic resin liquid 1. After the two phenolic resin applications are completed, the mesh tires are stacked in sequence, covered with a high-temperature resistant cloth with polytetrafluoroethylene on the surface, and cured and pressed.

[0108] It should be noted that the present invention sprays the surface of the single-layer reinforcement layer mesh through the above-mentioned process, applies a phenolic resin liquid with a residual carbon rate of 40-45%, and then applies a phenolic resin powder with a residual carbon rate of 55-60% to the surface of the mesh that has been sprayed with the phenolic resin liquid with the assistance of a vibrating screen; by controlling the residual carbon rates of the two phenolic resins, and by superimposing and curing the mesh to obtain a high-density reinforcement layer structure, the reinforcement layer has good impact resistance, bending resistance, scour resistance, and low porosity, which greatly enhances the carbon-carbon thermal insulation hard felt's ability to resist scour and erosion by high-speed airflow during use, and extends the product's service life.

[0109] As an optional embodiment, during the preparation of the composite layer, the step of applying a phenolic resin liquid with a residual carbon rate of 46-50% (for example, 46%, 47%, 48%, 49%, 50%, etc.) comprises: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to a surface density of 1100-1300 g / m 2 (For example, it can be 1100g / m 2 , 1120g / m 2 , 1140g / m 2 , 1150g / m 2 , 1160g / m 2 , 1180g / m 2 , 1200g / m 2 , 1220g / m 2 , 1240g / m 2 , 1250g / m2 , 1260g / m 2 , 1280g / m 2 , 1300g / m 2 The above phenolic resin liquid with a residual carbon rate of 46-50% is referred to as phenolic resin liquid III.

[0110] As an optional embodiment, in the process of preparing the composite layer, the thickness of the soft felt is ≥15 mm (for example, it can be 15 mm, 16 mm, 17 mm, 18 mm, 19 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, etc.), and the density is ≤0.085 g / cm 3 (For example, it can be 0.085g / cm 3 , 0.084g / cm 3 , 0.083g / cm 3 , 0.082g / cm 3 , 0.081g / cm 3 , 0.080g / cm 3 The viscosity of the phenolic resin liquid is ≥10000cps (for example, it can be 10000cps, 11000cps, 12000cps, 13000cps, 14000cps, 15000cps, 16000cps, 17000cps, 18000cps, 19000cps, 20000cps, etc.); the amount of the applied glue is 240-260g / m 2 (For example, it can be 240g / m 2 , 242g / m 2 , 244g / m 2 , 245g / m 2 , 246g / m 2 , 248g / m 2 , 250g / m 2 , 252g / m 2 , 254g / m 2 , 255g / m 2 , 256g / m 2 , 258g / m 2 , 260g / m 2 wait).

[0111] As an optional embodiment, during the preparation process of the composite layer, the curing temperature is 210-230°C (for example, it can be 210°C, 212°C, 212°C, 214°C, 216°C, 218°C, 220°C, 222°C, 224°C, 225°C, 226°C, 228°C, 230°C, etc.).

[0112] As an optional embodiment, the method for preparing the composite layer of the buffer layer and the reinforcement layer comprises the following steps:

[0113] The surface density is 1100~1300g / m 2 A soft felt is prepared, and a phenolic resin liquid III with a viscosity of ≥10000cps and a residual carbon rate of 46-50% is applied to its surface using a pneumatic spray gun. The phenolic resin liquid III is applied only to the upper surface of the soft felt (referring to the side close to the reinforcement layer and away from the side of the carbon-carbon thermal insulation hard felt matrix); after the phenolic resin is applied, the reinforcement layer and the high-temperature resistant cloth with polytetrafluoroethylene that have been cured and pressed are placed on the felt, and a press is used to perform high-temperature curing (without compression ratio) to complete the composite shaping of the buffer layer and the reinforcement layer, so as to obtain a composite layer of the buffer layer and the reinforcement layer.

[0114] It should be noted that the surface density of the present invention is 1100-1300g / m 2 The soft felt is applied with phenolic resin liquid with a residual carbon rate of 46-50%, and cured at high temperature without compression ratio to form a buffer layer between the reinforcement layer and the matrix. The buffer layer is a low-density buffer layer, 3. It has high porosity, high specific surface area, high thermal insulation performance and elasticity. The thermal conductivity of this layer is only about 0.1W / mk. The low thermal conductivity has good high-temperature impact resistance. During use, it can buffer and deform the difference in linear expansion coefficients of the surface reinforcement layer and the carbon-carbon thermal insulation hard felt matrix caused by high temperature, and reduce the probability of abnormal stratification caused by the difference in linear expansion coefficients during product use. In addition, the low-density buffer layer has a high specific surface area and good adsorption performance for corrosive and reactive gases. It can effectively adsorb corrosive and reactive gases that penetrate into the carbon-carbon thermal insulation hard felt matrix through the reinforcement layer during use, protect the carbon-carbon thermal insulation hard felt matrix, and extend the service life of the product.

[0115] As an optional embodiment, during the preparation of the carbon-carbon thermal insulation felt matrix, the step of applying a phenolic resin liquid with a residual carbon rate of 30-35% (for example, 30%, 31%, 32%, 33%, 34%, 35%, etc.) comprises: using a glue spraying device to apply the phenolic resin liquid with a residual carbon rate of 30-35% to a surface density of 800-1100 g / m 2 (For example, it can be 800g / m 2 , 820g / m 2 , 840g / m 2 , 850g / m 2 , 860g / m 2 , 880g / m 2 , 900g / m 2 , 920g / m 2 , 940g / m 2 , 950g / m2 , 960g / m 2 , 980g / m 2 1000g / m 2 , 1020g / m 2 , 1040g / m 2 , 1060g / m 2 , 1080g / m 2 , 1100g / m 2 [The above phenolic resin liquid with a residual carbon rate of 30-35% is referred to as phenolic resin liquid IV. ]

[0116] As an optional embodiment, during the preparation of the carbon-carbon thermal insulation felt matrix, the thickness of the soft felt is ≥10 mm (for example, it can be 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, etc.), and the density is ≤0.090 g / cm 3 (For example, it can be 0.090g / cm 3 , 0.089g / cm 3 , 0.088g / cm 3 , 0.087g / cm 3 , 0.086g / cm 3 The viscosity of the phenolic resin liquid is ≤400cps (for example, it can be 400cps, 390cps, 380cps, 360cps, 350cps, 340cps, 320cps, 300cps, 280cps, 260cps, 250cps, 240cps, 220cps, 200cps, 150cps, 100cps, 50cps, etc.); the applied material-liquid ratio is 1:(2.4-2.6) (for example, it can be 1:2.4, 1:2.45, 1:2.5, 1:2.55, 1:2.6, etc.).

[0117] As an optional embodiment, during the preparation process of the carbon-carbon thermal insulation felt matrix, the curing temperature is 210-230°C, for example, it can be 210°C, 212°C, 214°C, 215°C, 216°C, 218°C, 220°C, 222°C, 224°C, 226°C, 228°C, 230°C, etc.

[0118] As an optional embodiment, during the preparation process of the carbon-carbon thermal insulation felt matrix, the step of applying a phenolic resin liquid with a residual carbon rate of 46 to 50% (for example, it can be 46%, 47%, 48%, 49%, 50%, etc.) includes: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46 to 50% to the surface of the soft felt.

[0119] As an optional embodiment, in the step of applying a phenolic resin liquid with a residual carbon rate of 46-50% to prepare the carbon-carbon thermal insulation felt matrix, the viscosity of the phenolic resin liquid is ≥10000cps (for example, it can be 10000cps, 11000cps, 12000cps, 13000cps, 14000cps, 15000cps, 16000cps, 17000cps, 18000cps, 19000cps, 20000cps, etc.); the amount of the applied glue is 240-260g / m 2 (For example, it can be 240g / m 2 , 242g / m 2 , 244g / m 2 , 245g / m 2 , 246g / m 2 , 248g / m 2 , 250g / m 2 , 252g / m 2 , 254g / m 2 , 255g / m 2 , 256g / m 2 , 258g / m 2 , 260g / m 2 wait).

[0120] As an optional embodiment, during the preparation of the carbon-carbon thermal insulation felt matrix, the number of stacked layers is 5 to 65 layers, for example, it can be 5 layers, 10 layers, 15 layers, 20 layers, 25 layers, 30 layers, 35 layers, 40 layers, 45 layers, 50 layers, 55 layers, 60 layers, 65 layers, etc.

[0121] As an optional embodiment, during the preparation process of the carbon-carbon thermal insulation felt matrix, the temperature of the curing pressing is 210-230°C, for example, it can be 210°C, 212°C, 214°C, 215°C, 216°C, 218°C, 220°C, 222°C, 224°C, 226°C, 228°C, 230°C, etc., and the compression ratio of the curing pressing is (1.15-1.3):1, for example, it can be 1.15:1, 1.16:1, 1.18:1, 1.2:1, 1.22:1, 1.24:1, 1.26:1, 1.28:1, 1.3:1, etc.

[0122] As an optional embodiment, the method for preparing the carbon-carbon thermal insulation felt matrix comprises the following steps:

[0123] The surface density is 800~1100g / m 2The soft felt is subjected to glue spraying treatment, the soft felt is pushed into the glue spraying device, and the phenolic resin liquid IV with a residual carbon rate of 30-35% is sprayed on both sides by the glue spraying device. After the glue spraying is completed, the soft felt is dried by a hot air penetration oven with a radiation pre-drying device; after the soft felt is dried, a phenolic resin liquid III with a residual carbon rate of 46-50% is applied to the upper surface of each soft felt by using a pneumatic spray paint; after the glue spraying is completed, the soft felts are stacked in sequence and transferred to a press as a whole group for hot pressing and curing to obtain the carbon-carbon thermal insulation felt matrix.

[0124] As an optional embodiment, during the preparation of the composite carbon-carbon thermal insulation felt, the step of applying a phenolic resin liquid with a residual carbon rate of 46-50% (for example, 46%, 47%, 48%, 49%, 50%, etc.) includes: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the carbon-carbon thermal insulation felt substrate. [The above-mentioned phenolic resin liquid with a residual carbon rate of 46-50% is referred to as phenolic resin liquid three. ]

[0125] As an optional embodiment, in the step of applying a phenolic resin liquid with a residual carbon rate of 46-50% to prepare the composite carbon-carbon thermal insulation felt, the viscosity of the phenolic resin liquid is ≥10000cps (for example, it can be 10000cps, 11000cps, 12000cps, 13000cps, 14000cps, 15000cps, 16000cps, 17000cps, 18000cps, 19000cps, 20000cps, etc.); the amount of the applied glue is 240-260g / m 2 (For example, it can be 240g / m 2 , 242g / m 2 , 244g / m 2 , 245g / m 2 , 246g / m 2 , 248g / m 2 , 250g / m 2 , 252g / m 2 , 254g / m 2 , 255g / m 2 , 256g / m 2 , 258g / m 2 , 260g / m 2 wait).

[0126] As an optional embodiment, during the preparation of the composite carbon-carbon thermal insulation felt, the curing temperature is 210-230°C (for example, it can be 210°C, 212°C, 212°C, 214°C, 216°C, 218°C, 220°C, 222°C, 224°C, 225°C, 226°C, 228°C, 230°C, etc.).

[0127] As an optional embodiment, the preparation method of the composite carbon-carbon thermal insulation felt comprises the following steps:

[0128] The phenolic resin liquid three with a residual carbon rate of 46-50% is applied again to the upper surface of the finished carbon-carbon thermal insulation felt substrate. After the spraying is completed, the lower surface of the buffer layer of the composite layer of the buffer layer and the reinforcement layer that have been shaped is bonded to the upper surface of the substrate layer; after the bonding is completed, a high-temperature resistant cloth with polytetrafluoroethylene is placed on it, and a press is used for high-temperature curing (without compression ratio) to complete the hot pressing bonding of the buffer layer, the reinforcement layer composite and the carbon-carbon thermal insulation felt substrate to obtain the composite carbon-carbon thermal insulation felt.

[0129] As an optional embodiment, the carbonization procedure includes:

[0130] A protective gas is introduced into the carbonization furnace, and the temperature is started to rise after 3 to 5 hours (for example, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, etc.), and a corresponding process curve is set. The total time is 29 to 30 hours (for example, 29 hours, 29.2 hours, 29.4 hours, 29.5 hours, 29.6 hours, 29.8 hours, 30 hours, etc.) to heat to 940 to 960°C (for example, 940°C, 945°C, 950°C, 955°C, 960°C, etc.), and then heat-insulated at 940 to 960°C for 4 to 6 hours (for example, 4 hours, 4.5 hours, 5 hours, 5.5 hours, 6 hours, etc.), and then the temperature is lowered to 60 to 80°C (for example, 60°C, 65°C, 70°C, 75°C, 80°C, etc.) to stop carbonization.

[0131] It should be noted that the cured felt is placed in a carbonization furnace for carbonization treatment, so that the phenolic resin in the cured felt is carbonized in a high temperature environment. After the carbonization treatment, the cured felt becomes carbon felt.

[0132] Preferably, the high temperature treatment procedure includes:

[0133] The high temperature furnace is evacuated to a vacuum degree of less than -0.1 MPa, a protective gas is introduced, and a corresponding process curve is set. The total time is 48 to 52 h (for example, 48 h, 49 h, 50 h, 51 h, 52 h, etc.) to raise the temperature to 2250 to 2350 ° C (for example, 2250 ° C, 2260 ° C, 2280 ° C, 2300 ° C, 2320 ° C, 2340 ° C, 2350 ° C, etc.), and then heat-insulated at 2250 to 2350 ° C for 18 to 22 h (for example, 18 h, 19 h, 20 h, 21 h, 22 h, etc.), and then the temperature is reduced to 60 to 80 ° C (for example, 60 ° C, 62 ° C, 64 ° C, 66 ° C, 68 ° C, 70 ° C, 72 ° C, 74 ° C, 76 ° C, 78 ° C, 80 ° C, etc.) to stop the high temperature treatment.

[0134] In a second aspect, the present invention provides a composite carbon-carbon thermal insulation hard felt, such as Figure 1 As shown, the composite carbon-carbon thermal insulation hard felt comprises a reinforcing layer 1, a buffer layer 2 and a carbon-carbon thermal insulation hard felt matrix 3 stacked in sequence; and the composite carbon-carbon thermal insulation hard felt is prepared by the preparation method of the composite carbon-carbon thermal insulation hard felt described in the first aspect.

[0135] As an optional embodiment, the thickness of the reinforcement layer is 1 to 6.5 mm, for example, it can be 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, 6 mm, 6.5 mm, etc. The thickness of the buffer layer is 5 to 15 mm, for example, it can be 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm, etc. The thickness of the carbon-carbon thermal insulation hard felt substrate is 20 ~300mm, for example, it can be 20mm, 30mm, 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, 260mm, 270mm, 280mm, 290mm, 30mm, etc.

[0136] As an optional embodiment, the density of the reinforcement layer is 1.35-1.45 g / cm 3 , for example, it can be 1.35 g / cm 3 , 1.36g / cm 3 , 1.37g / cm 3 , 1.38g / cm 3 , 1.39g / cm 3 , 1.40g / cm 3 , 1.41g / cm 3 , 1.42g / cm 3 , 1.43g / cm 3 , 1.44g / cm 3 , 1.45g / cm 3 The density of the buffer layer is 0.080~0.085g / cm 3 , for example, it can be 0.080 g / cm 3 , 0.081g / cm 3 , 0.082g / cm 3 , 0.083g / cm 3 , 0.084g / cm 3 , 0.085g / cm 3The density of carbon-carbon thermal insulation hard felt matrix is ​​0.15~0.17g / cm 3 , for example, it can be 0.150 g / cm 3 , 0.152g / cm 3 、0.154g / cm 3 , 0.156g / cm 3 , 0.158g / cm 3 、0.160g / cm 3 , 0.162g / cm 3 , 0.164g / cm 3 , 0.166g / cm 3 、0.168g / cm 3 、0.170g / cm 3 wait.

[0137] As an optional embodiment, the porosity of the reinforcement layer is 15-20%, for example, it can be 15%, 15.5%, 16%, 16.5%, 17%, 17.5%, 18%, 18.5%, 19%, 19.5%, 20%, etc., the porosity of the buffer layer is 95-96%, for example, it can be 95%, 95.1%, 95.2%, 95.3%, 95.4%, 95.5%, 95.6%, 95.7%, 95.8%, 95.9%, 96%, etc., and the porosity of the carbon-carbon thermal insulation hard felt matrix is ​​90-92%, for example, it can be 90%, 90.2%, 90.4%, 90.6%, 90.8%, 91%, 91.2%, 91.4%, 91.6%, 91.8%, 92%, etc.

[0138] As an optional embodiment, the thermal conductivity of the reinforcement layer is, the thermal conductivity of the buffer layer is 0.05-0.10 W / mk, for example, 0.05 W / mk, 0.06 W / mk, 0.07 W / mk, 0.08 W / mk, 0.09 W / mk, 0.1 W / mk, etc., the thermal conductivity of the carbon-carbon thermal insulation hard felt matrix is ​​0.17-0.25 W / mk, for example, 0.17 W / mk, 0.18 W / mk, 0.19 W / mk, 0.20 W / mk, 0.21 W / mk, 0.22 W / mk, 0.23 W / mk, 0.24 W / mk, 0.25 W / mk, etc.

[0139] The present invention is further described below by means of specific examples and comparative examples. However, it should be understood that these examples are only used for more detailed description and should not be construed as limiting the present invention in any form.

[0140] Example 1

[0141] This embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, the preparation method comprising the following steps:

[0142] (A) Preparation of soft felt

[0143] Opening: Use mixed chopped carbon filaments with a length of 60 to 70 mm; put mixed chopped carbon filaments of different lengths into a stirring container, and achieve preliminary mixing of chopped carbon filaments of different lengths by mechanical stirring (70 rpm, 4 min); pour the mixed chopped carbon filaments that have completed preliminary mixing onto the transmission curtain of the bag opener, and feed them into the multi-roller opener through the metal impurity remover to achieve opening and mixing of the chopped carbon filaments (there are 6 pairs of opening rollers, the parameters of the opening rollers are set to 15 Hz, and the cylinder speed is set to 47 Hz);

[0144] Web formation: After being opened by a multi-roller opener, the fibers are sent into a cotton box through a high-speed airflow. The opened fiber clusters are lifted upward by the conveying nail curtain to the cotton-evening roller and the cotton-dropping roller. After being evened and measured by the cotton-evening roller, the fiber clusters are stripped off by the cotton-dropping roller and transferred to the vibration plate. The vibration of the vibration plate drives the fiber clusters to fall and evenly stack on the conveying leather curtain to form continuous fiber clusters. After being measured by a precise metering device, the continuous fiber clusters are sent into the high-speed cylinder by the feeding roller (the cylinder speed is set to 1250rpm). The cylinder combs the fiber clusters at high speed to form a fiber web. The fiber web is adsorbed by the air-permeable curtain with negative pressure and stripped off from the high-speed cylinder to form a highly disordered, isotropic, continuous, and strong fiber web.

[0145] Composite reinforcement: The carbon fiber web is fed into the reciprocating web laying curtain through the conveyor curtain. The carbon fiber web passes through the feeding curtain, annular curtain, reciprocating curtain, and output nip roller of the reciprocating web laying machine in turn, and then is reciprocated and stacked in a Z shape according to the parameter setting value, and then is needle-punched and cut to obtain soft felt;

[0146] The number of layers of Z-shaped reciprocating stacking is set to 18 layers, and the density of needle punching reinforcement is 18 needles / cm 2 , the surface density can be obtained to be 900g / m 2 of soft felt;

[0147] The number of layers of Z-shaped reciprocating stacking is set to 24, and the density of needle punching reinforcement is 22 needles / cm 2 , the surface density can be obtained to be 1200g / m 2 of soft felt.

[0148] (B) Preparation of reinforcement layer

[0149] Preparation of reinforcing layer web: Mixed short carbon filaments with a length of 60-70 mm are placed on a roller carding machine for opening and carding (the cylinder speed is set to a linear speed of 1150 m / min, the working roller linear speed is 60 m / min, and the number of working rollers is 7 groups), needle punching (needle punching density is 12 needles / cm2 The needle-punching direction is upward, that is, perpendicular to the fiber web) to form a reinforcing layer web with a surface density of 200g / m 2 ;

[0150] Compression of the reinforcement layer: Use a peristaltic pump and a resin spraying device with a gear pump to spray the surface of the single-layer reinforcement layer mesh tire, apply a phenolic resin liquid 1 with a viscosity of 800cps and a residual carbon rate of 43%, and the spraying mass ratio is 1:1.5. After spraying, let it stand in a container with polytetrafluoroethylene for 1 hour; after standing, transfer the container as a whole to a vibrating screen (vibration frequency of 15Hz), and apply phenolic resin powder 2 to the surface of the mesh tire that has been sprayed with phenolic resin liquid 1. The residual carbon rate of the phenolic resin powder 2 is 57%, and the application mass ratio is 1:0.7; After completing the two phenolic resin applications, the mesh tires are stacked in sequence, covered with a high-temperature resistant cloth with polytetrafluoroethylene on the surface, and cured and pressed. The pressing temperature is 175°C and the compression ratio is 6.5:1;

[0151] The number of web stacking layers is set to 5, and the thickness of the single sheet is 1.5 mm, and the surface density is 1000 ± 50 g / m 2 reinforcement layer.

[0152] (C) Preparation of composite layer containing buffer layer and reinforcement layer

[0153] The thickness of the single sheet obtained in step (A) is 15 mm and the surface density is 1200 g / m 2 , density is 0.085g / cm 3 The soft felt is sprayed with a pneumatic spray gun. The phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% is sprayed on its surface. The spraying amount is 250g / m 2 , only apply resin to the upper surface of the soft felt; after the surface resin is applied, cover it with the cured and pressed reinforcement layer and the high-temperature resistant cloth with polytetrafluoroethylene, use a press to perform high-temperature curing at a temperature of 220°C, with no compression ratio, to complete the composite shaping of the buffer layer and the reinforcement layer.

[0154] (D) Preparation of carbon-carbon thermal insulation felt matrix

[0155] Glue spraying and curing: The single sheet obtained in step (A) is selected with a thickness of 10 mm and a surface density of 900 g / m 2 , density is 0.090g / cm 3 The soft felt is subjected to glue spraying treatment, and the soft felt is pushed into the glue spraying device, and the total glue spraying amount is soft felt: water-soluble phenolic resin liquid four = 1:2.5, the viscosity of the water-soluble phenolic resin liquid four is 300cps, and the carbon residue of the resin is 34%, and double-sided glue spraying is performed; after the glue spraying is completed, the soft felt is dried using a hot air (temperature of 120°C) penetration oven with a radiation pre-drying device;

[0156] Laying hot pressing: After the soft felt is dried, a phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% is applied to the upper surface of each soft felt using pneumatic spraying. The spraying amount is 250g / m 2 After three sprayings of phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% were completed, the soft felt was stacked in sequence (10 layers) and transferred to a press as a whole group for hot pressing and curing at a curing temperature of 220°C and a compression ratio of 1.2:1 to produce a carbon-carbon thermal insulation felt matrix.

[0157] (E) Preparation of composite carbon-carbon thermal insulation felt

[0158] The phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% was applied again to the upper surface of the carbon-carbon insulation felt substrate. The amount of the third spray was 250g / m 2 ; After the glue spraying is completed, the soft felt surface of the buffer layer of the finalized buffer layer and reinforcement layer composite is bonded to the upper surface of the carbon-carbon thermal insulation felt; after the buffer layer and reinforcement layer composite are bonded to the carbon-carbon thermal insulation felt matrix, a high-temperature resistant cloth with polytetrafluoroethylene is placed on it, and a press is used for high-temperature curing at a curing temperature of 220°C with no compression ratio to complete the hot pressing composite of the buffer layer and reinforcement layer composite and the carbon-carbon thermal insulation felt matrix to obtain the composite carbon-carbon thermal insulation felt.

[0159] (F) Preparation of composite carbon-carbon thermal insulation hard felt

[0160] Carbonization treatment: the cured felt is placed in a carbonization furnace for carbonization treatment, so that the phenolic resin in the cured felt is carbonized in a high temperature environment; nitrogen is introduced into the carbonization furnace, and the temperature is raised after the nitrogen is introduced for 4 hours, and the corresponding process curve is set. The total time is 29.5 hours to increase to 950°C, the temperature is kept constant for 5 hours, and then the temperature is lowered to 70°C to obtain carbon felt;

[0161] High temperature treatment: the carbon felt is placed in a high temperature furnace for high temperature treatment at 2300°C; the high temperature furnace is evacuated to a vacuum degree of -0.1Mpa, and argon is introduced, and the corresponding process curve is set. The total time is 50 hours, the temperature is raised to 2300°C, and the temperature is kept for 20 hours, and then the temperature is lowered to 70°C. The production of the carbon-carbon thermal insulation hard felt is completed.

[0162] Example 2

[0163] This embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, the preparation method comprising the following steps:

[0164] (A) Preparation of soft felt

[0165] Opening: Use mixed chopped carbon filaments with a length of 70 to 90 mm; put mixed chopped carbon filaments of different lengths into a stirring container, and achieve preliminary mixing of chopped carbon filaments of different lengths by mechanical stirring (65 rpm, 5 min); pour the mixed chopped carbon filaments that have completed preliminary mixing onto the transmission curtain of the bag opener, and feed them into the multi-roller opener through the metal impurity remover to achieve opening and mixing of the chopped carbon filaments (there are 6 pairs of opening rollers, the parameters of the opening rollers are set to 16 Hz, and the cylinder speed is set to 45 Hz);

[0166] Web formation: After being opened by a multi-roller opener, the fibers are sent into a cotton box through a high-speed airflow. The opened fiber clusters are lifted upward by the conveying nail curtain to the cotton-evening roller and the cotton-dropping roller. After being evened and measured by the cotton-evening roller, the fiber clusters are stripped off by the cotton-dropping roller and transferred to the vibration plate. The vibration of the vibration plate drives the fiber clusters to fall and evenly stack on the conveying leather curtain to form continuous fiber clusters. After being measured by a precise metering device, the continuous fiber clusters are sent into the high-speed cylinder by the feeding roller (the cylinder speed is set to 1200rpm). The cylinder combs the fiber clusters at high speed to form a fiber web. The fiber web is adsorbed by the air-permeable curtain with negative pressure and stripped off from the high-speed cylinder to form a highly disordered, isotropic, continuous, and strong fiber web.

[0167] Composite reinforcement: The carbon fiber web is fed into the reciprocating web laying curtain through the conveyor curtain. The carbon fiber web passes through the feeding curtain, annular curtain, reciprocating curtain, and output nip roller of the reciprocating web laying machine in turn, and then is reciprocated and stacked in a Z shape according to the parameter setting value, and then is needle-punched and cut to obtain soft felt;

[0168] The number of layers of Z-shaped reciprocating stacking is set to 18 layers, and the density of needle punching reinforcement is 18 needles / cm 2 , the surface density can be obtained to be 900g / m 2 of soft felt;

[0169] The number of layers of Z-shaped reciprocating stacking is set to 24, and the density of needle punching reinforcement is 22 needles / cm 2 , the surface density can be obtained to be 1200g / m 2 of soft felt.

[0170] (B) Preparation of reinforcement layer

[0171] Preparation of reinforcing layer web: Mixed short carbon filaments with a length of 70-90 mm are placed on a roller carding machine for opening and carding (the cylinder speed is set to a linear speed of 1200 m / min, the working roller linear speed is 70 m / min, and the number of working rollers is 6 groups), needle punching (needle punching density is 10 needles / cm 2 The needle-punching direction is upward, that is, perpendicular to the fiber web) to form a reinforcing layer web with a surface density of 180g / m 2 ;

[0172] Compression of the reinforcement layer: Use a peristaltic pump and a resin spraying device with a gear pump to spray the surface of the single-layer reinforcement layer mesh tire, apply a phenolic resin liquid 1 with a viscosity of 800cps and a residual carbon rate of 43%, and the spraying mass ratio is 1:1.5. After spraying, let it stand in a container with polytetrafluoroethylene for 1 hour; after standing, transfer the container as a whole to a vibrating screen (vibration frequency of 15Hz), and apply phenolic resin powder 2 to the surface of the mesh tire that has been sprayed with phenolic resin liquid 1. The residual carbon rate of the phenolic resin powder 2 is 57%, and the application mass ratio is 1:0.7; After completing the two phenolic resin applications, the mesh tires are stacked in sequence, covered with a high-temperature resistant cloth with polytetrafluoroethylene on the surface, and cured and pressed. The pressing temperature is 170°C and the compression ratio is 7.0;

[0173] The number of web stacking layers is set to 5, and the thickness of the single sheet is 1.5 mm, and the surface density is 1000 ± 50 g / m 2 reinforcement layer.

[0174] (C) Preparation of composite layer containing buffer layer and reinforcement layer

[0175] The thickness of the single sheet obtained in step (A) is 15 mm and the surface density is 1200 g / m 2 , density is 0.085g / cm 3 The soft felt is sprayed with a pneumatic spray gun. The phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% is sprayed on its surface. The spraying amount is 250g / m 2 , only apply resin to the upper surface of the soft felt; after the surface resin is applied, cover it with the cured and pressed reinforcement layer and the high-temperature resistant cloth with polytetrafluoroethylene, use a press to perform high-temperature curing at a temperature of 220°C, with no compression ratio, to complete the composite shaping of the buffer layer and the reinforcement layer.

[0176] (D) Preparation of carbon-carbon thermal insulation felt matrix

[0177] Glue spraying and curing: The single sheet obtained in step (A) is selected with a thickness of 10 mm and a surface density of 900 g / m 2 , density is 0.090g / cm 3 The soft felt is subjected to glue spraying treatment, and the soft felt is pushed into the glue spraying device, and the total glue spraying amount is soft felt: water-soluble phenolic resin liquid four = 1:2.5, the viscosity of the water-soluble phenolic resin liquid four is 300cps, and the carbon residue of the resin is 34%, and double-sided glue spraying is performed; after the glue spraying is completed, the soft felt is dried using a hot air (temperature of 120°C) penetration oven with a radiation pre-drying device;

[0178] Laying hot pressing: After the soft felt is dried, a phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% is applied to the upper surface of each soft felt using pneumatic spraying. The spraying amount is 250g / m2 After three sprayings of phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% were completed, the soft felt was stacked in sequence (10 layers) and transferred to a press as a whole group for hot pressing and curing at a curing temperature of 220°C and a compression ratio of 1.2:1 to produce a carbon-carbon thermal insulation felt matrix.

[0179] (E) Preparation of composite carbon-carbon thermal insulation felt

[0180] The phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% was applied again to the upper surface of the carbon-carbon insulation felt substrate. The amount of the third spray was 250g / m 2 ; After the glue spraying is completed, the soft felt surface of the buffer layer of the finalized buffer layer and reinforcement layer composite is bonded to the upper surface of the carbon-carbon thermal insulation felt; after the buffer layer and reinforcement layer composite are bonded to the carbon-carbon thermal insulation felt matrix, a high-temperature resistant cloth with polytetrafluoroethylene is placed on it, and a press is used for high-temperature curing at a curing temperature of 220°C with no compression ratio to complete the hot pressing composite of the buffer layer and reinforcement layer composite and the carbon-carbon thermal insulation felt matrix to obtain the composite carbon-carbon thermal insulation felt.

[0181] (F) Preparation of composite carbon-carbon thermal insulation hard felt

[0182] Carbonization treatment: the cured felt is placed in a carbonization furnace for carbonization treatment, so that the phenolic resin in the cured felt is carbonized in a high temperature environment; nitrogen is introduced into the carbonization furnace, and the temperature is raised after the nitrogen is introduced for 4 hours, and the corresponding process curve is set. The total time is 29.5 hours to increase to 950°C, the temperature is kept constant for 5 hours, and then the temperature is lowered to 60°C to obtain carbon felt;

[0183] High temperature treatment: the carbon felt is placed in a high temperature furnace for high temperature treatment at 2300°C; the high temperature furnace is evacuated to a vacuum degree of -0.1Mpa, and argon is introduced, and the corresponding process curve is set. The total time is 50 hours, the temperature is raised to 2300°C, kept warm for 20 hours, and then cooled to 60°C. The production of the carbon-carbon thermal insulation hard felt is completed.

[0184] Example 3

[0185] This embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, the preparation method comprising the following steps:

[0186] (A) Preparation of soft felt

[0187] Opening: Use mixed chopped carbon filaments with a length of 50 to 60 mm; put mixed chopped carbon filaments of different lengths into a stirring container, and achieve preliminary mixing of chopped carbon filaments of different lengths by mechanical stirring (75 rpm, 3 min); pour the mixed chopped carbon filaments that have completed preliminary mixing onto the transmission curtain of the bag opener, and feed them into the multi-roller opener through the metal impurity remover to achieve opening and mixing of the chopped carbon filaments (there are 6 pairs of opening rollers, the parameters of the opening rollers are set to 14 Hz, and the cylinder speed is set to 48 Hz);

[0188] Web formation: After being opened by a multi-roller opener, the fibers are sent into a cotton box through a high-speed airflow. The opened fiber clusters are lifted upward by the conveying nail curtain to the cotton-evening roller and the cotton-dropping roller. After being evened and measured by the cotton-evening roller, the fiber clusters are stripped off by the cotton-dropping roller and transferred to the vibration plate. The vibration of the vibration plate drives the fiber clusters to fall and evenly stack on the conveying leather curtain to form continuous fiber clusters. After being measured by a precise metering device, the continuous fiber clusters are sent into the high-speed cylinder by the feeding roller (the cylinder speed is set to 1300rpm). The cylinder combs the fiber clusters at high speed to form a fiber web. The fiber web is adsorbed by the air-permeable curtain with negative pressure and stripped off from the high-speed cylinder to form a highly disordered, isotropic, continuous, and strong fiber web.

[0189] Composite reinforcement: The carbon fiber web is fed into the reciprocating web laying curtain through the conveyor curtain. The carbon fiber web passes through the feeding curtain, annular curtain, reciprocating curtain, and output nip roller of the reciprocating web laying machine in turn, and then is reciprocated and stacked in a Z shape according to the parameter setting value, and then is needle-punched and cut to obtain soft felt;

[0190] The number of layers of Z-shaped reciprocating stacking is set to 18 layers, and the density of needle punching reinforcement is 18 needles / cm 2 , the surface density can be obtained to be 900g / m 2 of soft felt;

[0191] The number of layers of Z-shaped reciprocating stacking is set to 24, and the density of needle punching reinforcement is 22 needles / cm 2 , the surface density can be obtained to be 1200g / m 2 of soft felt.

[0192] (B) Preparation of reinforcement layer

[0193] Preparation of reinforcing layer web: Mixed short carbon filaments with a length of 50-60 mm are placed on a roller carding machine for opening and carding (the cylinder speed is set to a linear speed of 1100 m / min, the working roller linear speed is 50 m / min, and the number of working rollers is 8 groups), needle punching (needle punching density is 15 needles / cm 2 The needle-punching direction is upward, that is, perpendicular to the fiber web) to form a reinforcing layer web with a surface density of 220g / m 2 ;

[0194] Compression of the reinforcement layer: Use a peristaltic pump and a resin spraying device with a gear pump to spray the surface of the single-layer reinforcement layer mesh tire, apply a phenolic resin liquid 1 with a viscosity of 800cps and a residual carbon rate of 43%, and the spraying mass ratio is 1:1.5. After spraying, let it stand in a container with polytetrafluoroethylene for 1 hour; after standing, transfer the container as a whole to a vibrating screen (vibration frequency of 15Hz), and apply phenolic resin powder 2 to the surface of the mesh tire that has been sprayed with phenolic resin liquid 1. The residual carbon rate of the phenolic resin powder 2 is 57%, and the application mass ratio is 1:0.7; After completing the two phenolic resin applications, the mesh tires are stacked in sequence, covered with a high-temperature resistant cloth with polytetrafluoroethylene on the surface, and cured and pressed. The pressing temperature is 180°C and the compression ratio is 6.8;

[0195] The number of web stacking layers is set to 5, and the thickness of the single sheet is 1.5 mm, and the surface density is 1100 ± 50 g / m 2 reinforcement layer.

[0196] (C) Preparation of composite layer containing buffer layer and reinforcement layer

[0197] The thickness of the single sheet obtained in step (A) is 15 mm and the surface density is 1200 g / m 2 , density is 0.085g / cm 3 The soft felt is sprayed with a pneumatic spray gun. The phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% is sprayed on its surface. The spraying amount is 250g / m 2 , only apply resin to the upper surface of the soft felt; after the surface resin is applied, cover it with the cured and pressed reinforcement layer and the high-temperature resistant cloth with polytetrafluoroethylene, use a press to perform high-temperature curing at a temperature of 220°C, with no compression ratio, to complete the composite shaping of the buffer layer and the reinforcement layer.

[0198] (D) Preparation of carbon-carbon thermal insulation felt matrix

[0199] Glue spraying and curing: The single sheet obtained in step (A) is selected with a thickness of 10 mm and a surface density of 900 g / m 2 , density is 0.090g / cm 3 The soft felt is subjected to glue spraying treatment, and the soft felt is pushed into the glue spraying device, and the total glue spraying amount is soft felt: water-soluble phenolic resin liquid four = 1:2.5, the viscosity of the water-soluble phenolic resin liquid four is 300cps, and the carbon residue of the resin is 34%, and double-sided glue spraying is performed; after the glue spraying is completed, the soft felt is dried using a hot air (temperature of 120°C) penetration oven with a radiation pre-drying device;

[0200] Laying hot pressing: After the soft felt is dried, a phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% is applied to the upper surface of each soft felt using pneumatic spraying. The spraying amount is 250g / m2 After three sprayings of phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% were completed, the soft felt was stacked in sequence (10 layers) and transferred to a press as a whole group for hot pressing and curing at a curing temperature of 220°C and a compression ratio of 1.2:1 to produce a carbon-carbon thermal insulation felt matrix.

[0201] (E) Preparation of composite carbon-carbon thermal insulation felt

[0202] The phenolic resin liquid with a viscosity of 12000cps and a residual carbon rate of 47% was applied again to the upper surface of the carbon-carbon insulation felt substrate. The amount of the third spray was 250g / m 2 ; After the glue spraying is completed, the soft felt surface of the buffer layer of the finalized buffer layer and reinforcement layer composite is bonded to the upper surface of the carbon-carbon thermal insulation felt; after the buffer layer and reinforcement layer composite are bonded to the carbon-carbon thermal insulation felt matrix, a high-temperature resistant cloth with polytetrafluoroethylene is placed on it, and a press is used for high-temperature curing at a curing temperature of 220°C with no compression ratio to complete the hot pressing composite of the buffer layer and reinforcement layer composite and the carbon-carbon thermal insulation felt matrix to obtain the composite carbon-carbon thermal insulation felt.

[0203] (F) Preparation of composite carbon-carbon thermal insulation hard felt

[0204] Carbonization treatment: the cured felt is placed in a carbonization furnace for carbonization treatment, so that the phenolic resin in the cured felt is carbonized in a high temperature environment; nitrogen is introduced into the carbonization furnace, and the temperature is raised after the nitrogen is introduced for 4 hours, and the corresponding process curve is set. The total time is 29.5 hours to increase to 950°C, the temperature is kept constant for 5 hours, and then the temperature is lowered to 80°C to obtain carbon felt;

[0205] High temperature treatment: the carbon felt is placed in a high temperature furnace for high temperature treatment at 2300°C; the high temperature furnace is evacuated to a vacuum degree of -0.1Mpa, and argon is introduced, and the corresponding process curve is set. The total time is 50 hours, the temperature is raised to 2300°C, and the temperature is kept for 20 hours, and then the temperature is lowered to 80°C. The production of the carbon-carbon thermal insulation hard felt is completed.

[0206] Example 4

[0207] This embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which is different from the embodiment 1 in that the surface density of 900g / m 2 The soft felt is replaced with a surface density of 800g / m 2 The soft felt has a surface density of 1200g / m 2 The soft felt is replaced with a surface density of 1100g / m 2 The other steps are exactly the same as those in Example 1.

[0208] Example 5

[0209] This embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which is different from the embodiment 1 in that the surface density of 900g / m 2 The soft felt is replaced with a surface density of 1000g / m 2 The soft felt has a surface density of 1200g / m 2 The soft felt is replaced with a surface density of 1300g / m 2 The other steps are exactly the same as those in Example 1.

[0210] Example 6

[0211] The present embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which is different from Example 1 only in that the length of the mixed chopped carbon filaments is 40 to 120 mm, wherein the chopped carbon filaments with a length of 40 to 60 mm account for 60wt%, the chopped carbon filaments with a length of 100 to 120 mm account for 20wt%, and the chopped carbon filaments with a length of 60 to 100 mm account for 20wt%, and the other steps are exactly the same as Example 1.

[0212] Example 7

[0213] The present embodiment provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which is different from Example 1 only in that the length of the mixed chopped carbon filaments is 40 to 120 mm, wherein the chopped carbon filaments with a length of 40 to 60 mm account for 40wt%, the chopped carbon filaments with a length of 100 to 120 mm account for 5wt%, and the chopped carbon filaments with a length of 60 to 100 mm account for 55wt%, and the other steps are exactly the same as in Example 1.

[0214] Comparative Example 1

[0215] This comparative example provides a method for preparing a carbon-carbon thermal insulation hard felt, which is different from Example 1 only in that no reinforcement layer is provided, and the buffer layer and the carbon-carbon thermal insulation felt substrate are directly bonded, and the other steps are consistent with Example 1.

[0216] Comparative Example 2

[0217] This comparative example provides a method for preparing a carbon-carbon thermal insulation hard felt, which is different from Example 1 only in that no buffer layer is provided, and the reinforcing layer and the carbon-carbon thermal insulation felt substrate are directly bonded, and the other steps are consistent with Example 1.

[0218] Comparative Example 3

[0219] This comparative example provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which differs from Example 1 only in that, during the preparation of the reinforcement layer: a phenolic resin liquid 1 with a residual carbon rate of 43% is replaced by a phenolic resin liquid 4 with a residual carbon rate of 34%, and the spraying mass ratio is 1:2, and the other steps are consistent with Example 1.

[0220] Comparative Example 4

[0221] This comparative example provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which differs from Example 1 only in that, during the preparation of the reinforcement layer: phenolic resin liquid 1 with a residual carbon rate of 43% is replaced by phenolic resin liquid 3 with a residual carbon rate of 47%, and the spraying mass ratio is 1:2, and the other steps are consistent with Example 1.

[0222] Comparative Example 5

[0223] This comparative example provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which is different from Example 1 only in that, during the preparation of the reinforcement layer, a phenolic resin liquid 1 with a viscosity of 800cps and a residual carbon rate of 43% is applied, and the spraying mass ratio is 1:2. After the spraying is completed, it is allowed to stand in a container with polytetrafluoroethylene for 1 hour; after the standing is completed, the phenolic resin powder 2 is no longer applied, and the other steps are consistent with Example 1.

[0224] Comparative Example 6

[0225] This comparative example provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which differs from Example 1 only in that, during the preparation of the reinforcement layer, the phenolic resin liquid 1 is no longer sprayed, and the single-layer reinforcement layer mesh is directly applied with phenolic resin powder 2, and the applied mass ratio is increased to 1:2. The other steps are consistent with Example 1.

[0226] Comparative Example 7

[0227] This comparative example provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which differs from Example 1 only in that, during the preparation of the composite layer containing a buffer layer and a reinforcement layer, phenolic resin liquid three with a residual carbon rate of 47% is replaced by phenolic resin liquid one with a residual carbon rate of 43%, and the other steps are consistent with Example 1.

[0228] Comparative Example 8

[0229] This comparative example provides a method for preparing a composite carbon-carbon thermal insulation hard felt, which differs from Example 1 only in that, during the preparation of the composite layer containing a buffer layer and a reinforcement layer, the phenolic resin liquid three with a residual carbon rate of 47% is replaced by a phenolic resin liquid with a residual carbon rate of 57%, and the other steps are consistent with Example 1.

[0230] Test Example 1

[0231] Test sample: the composite carbon-carbon thermal insulation hard felt provided in Examples 1 to 7.

[0232] Test methods: GB / T 10295-2008 "Determination of steady-state thermal resistance and related properties of insulation materials - Heat flow meter method", GB / T 3365-2008 "Test method for pore content of carbon fiber reinforced plastics", ASTM C559-2016 "Standard test method for bulk density of carbon and graphite materials".

[0233] The specific test results are shown in Table 1:

[0234] Table 1

[0235]

[0236] Test Example 2

[0237] Test samples: the composite carbon-carbon thermal insulation hard felt provided in Examples 1 to 7 and the composite carbon-carbon thermal insulation hard felt provided in Comparative Examples 1 to 8.

[0238] Test methods: GB / T 33501-2017 “Test method for tensile properties of carbon / carbon composite materials”, GB / T 3356-2014 “Test method for flexural properties of oriented fiber reinforced polymer matrix composites”.

[0239] The specific test results are shown in Table 2:

[0240] Table 2

[0241]

[0242]

[0243] As shown in Table 2, the tensile strength of the carbon-carbon thermal insulation felt provided by the present invention can reach more than 105MPa, the flexural strength can reach more than 208MPa, and the service life is more than 180 days. Examples 1 to 3 are preferred schemes, and the tensile strength of the carbon-carbon thermal insulation felt provided can reach more than 118MPa, the flexural strength can reach more than 217MPa, and the service life is more than 180 days. This fully illustrates that the multi-layer composite structure of the high-density reinforcement layer, low-density buffer layer, and carbon-carbon thermal insulation felt matrix adopted by the present invention; the high-density anti-scouring reinforcement layer and the low-density, high specific surface area buffer layer are added to the surface of the traditional carbon-carbon thermal insulation felt in the form of high-temperature composite, which greatly improves the service life of the carbon-carbon thermal insulation felt under special working conditions such as high temperature, high-speed airflow scouring, and corrosive steam, and the comprehensive service life can reach more than 6 times that of the traditional carbon-carbon thermal insulation felt.

[0244] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a composite carbon-carbon thermal insulation hard felt, characterized in that: The preparation method comprises: Preparation of soft felt: Short-cut carbon fiber filaments are opened and meshed to obtain a carbon fiber mesh; the carbon fiber mesh is stacked in a Z-shaped reciprocating manner and then reinforced by needle punching to obtain a surface density of 800 to 1300 g / m 2 of soft felt; Preparation of the reinforcement layer: The short chopped carbon fiber filaments are opened and needled to obtain a surface density of 150-250g / m 2 A reinforcing layer mesh; applying a phenolic resin liquid with a carbon content of 40 to 45% to the surface of the single-piece reinforcing layer mesh, and then applying a phenolic resin powder with a residual carbon content of 55 to 60%; stacking and curing and pressing the single-piece mesh after applying the phenolic resin twice to obtain a reinforcing layer; Preparation of composite layer: Surface density is 1100~1300g / m 2 A phenolic resin liquid with a residual carbon rate of 46-50% is applied to the surface of the soft felt to cover the reinforcing layer, and the composite layer of the buffer layer and the reinforcing layer is obtained after curing; Preparation of carbon-carbon thermal insulation felt matrix: single sheet surface density is 800-1100g / m 2 Applying phenolic resin liquid with a residual carbon rate of 30-35% on both sides of the soft felt, and then applying phenolic resin liquid with a residual carbon rate of 46-50% after curing; stacking and curing and pressing the single soft felt after applying the phenolic resin to obtain a carbon-carbon thermal insulation felt matrix; Preparation of composite carbon-carbon thermal insulation felt: applying phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the carbon-carbon thermal insulation felt substrate, covering the composite layer, and curing to obtain the composite carbon-carbon thermal insulation felt; Preparation of composite carbon-carbon thermal insulation hard felt: the composite carbon-carbon thermal insulation felt is carbonized and subjected to high-temperature treatment to obtain the composite carbon-carbon thermal insulation hard felt.

2. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: In the preparation process of the soft felt, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm; and in the mixed chopped carbon filaments: the chopped carbon filaments with a length of less than 60 mm account for less than 50wt%, and the chopped carbon filaments with a length of more than 100 mm account for ≥10wt%; And / or, in the preparation process of the soft felt, the opening step includes: stirring the chopped carbon fiber filaments to obtain preliminary mixed carbon filaments; opening the preliminary mixed carbon filaments through a multi-roller opening machine to obtain mixed carbon filaments; wherein the stirring speed is 65-75rpm, and the stirring time is 3-5min; the parameters of the multi-roller opening machine include: 4-8 pairs of opening rollers, the frequency of the opening rollers is 10-20Hz, and the frequency of the cylinder is 40-50Hz; And / or, in the preparation process of the soft felt, the web-forming step includes: sending the mixed carbon filaments obtained by opening into a cotton box through a high-speed airflow to form a fiber mass, combing it through a high-speed cylinder to form a fiber web, and stripping it from the high-speed cylinder through negative pressure adsorption to obtain a carbon fiber web; wherein the rotation speed of the high-speed cylinder is 1200-1300rpm; the negative pressure adsorption is provided by fans on both sides, and the frequency of the fans is 30-40Hz; And / or, in the preparation process of the soft felt, when the surface density of the soft felt is 1100-1300 g / m 2 When the number of layers of the reciprocating stacking is 22 to 26, the density of the needle punching reinforcement is 15 to 25 needles / cm 2 When the surface density of the soft felt is 800 to 1100 g / m 2 When the number of layers of the reciprocating stacking is 16 to 22 layers, the density of the needle punching reinforcement is 15 to 25 needles / cm 2 .

3. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: In the process of preparing the reinforcement layer, the chopped carbon fiber filaments are selected from mixed chopped carbon filaments with a length of 40 to 120 mm; And / or, in the preparation process of the reinforcement layer, the opening step includes: opening and combing the chopped carbon fiber filaments through a roller carding machine to obtain mixed carbon filaments; wherein the parameters of the roller carding machine include: 6 to 8 groups of working rollers, the linear speed of the working rollers is 50 to 70 m / min, and the linear speed of the cylinder is 1100 to 1200 m / min; And / or, in the process of preparing the reinforcing layer, the needling step includes: needling the mixed carbon filaments obtained by opening to obtain a carbon fiber having a surface density of 150 to 250 g / m 2 wherein the density of the needle punching is 10 to 15 needles / cm 2 ; And / or, in the process of preparing the reinforcing layer, the step of applying the phenolic resin liquid with a carbon content of 40-45% comprises: spraying the surface of the single-piece reinforcing layer mesh and then letting it stand; wherein the viscosity of the phenolic resin liquid is less than 1000cps; the spraying material-liquid ratio is 1:(1.4-1.6), and the standing time is 0.5-2h; And / or, in the process of preparing the reinforcing layer, the step of applying phenolic resin powder with a residual carbon rate of 55-60% comprises: applying phenolic resin liquid on one side of the surface of the reinforcing layer mesh under vibration, and then applying phenolic resin powder with a residual carbon rate of 55-60%; wherein the vibration frequency is 13-18 Hz; the applied material-to-powder ratio is 1:(0.6-0.8); And / or, in the process of preparing the reinforcing layer, the number of the stacked layers is 4 to 10; And / or, during the preparation of the reinforcement layer, the temperature of the curing and pressing is 170-180° C., and the compression ratio of the curing and pressing is ≥6.

5.

4. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: In the process of preparing the composite layer, the step of applying the phenolic resin liquid with a residual carbon rate of 46-50% comprises: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to a surface density of 1100-1300g / m 2 The surface of the soft felt; wherein the thickness of the soft felt is ≥15mm and the density is ≤0.085g / cm 3 ; The viscosity of the phenolic resin liquid is ≥10000cps; The amount of the applied glue is 240-260g / m 2 ; And / or, the curing temperature is 210-230°C.

5. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: In the preparation process of the carbon-carbon thermal insulation felt matrix, the step of applying the phenolic resin liquid with a residual carbon rate of 30-35% comprises: using a glue spraying device to apply the phenolic resin liquid with a residual carbon rate of 30-35% to a surface density of 800-1100g / m 2 The soft felt has a thickness of ≥10 mm and a density of ≤0.090 g / cm 3 ; The viscosity of the phenolic resin liquid is ≤400cps; the applied material-liquid ratio is 1:(2.4-2.6); And / or, during the preparation of the carbon-carbon thermal insulation felt matrix, the curing temperature is 210-230°C; And / or, in the process of preparing the carbon-carbon thermal insulation felt matrix, the step of applying the phenolic resin liquid with a residual carbon rate of 46-50% comprises: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the soft felt; wherein the viscosity of the phenolic resin liquid is ≥10000cps; the amount of the applied spray glue is 240-260g / m 2 ; And / or, in the process of preparing the carbon-carbon thermal insulation felt matrix, the number of stacked layers is 5 to 65; And / or, during the preparation of the carbon-carbon thermal insulation felt matrix, the temperature of the curing and pressing is 210-230° C., and the compression ratio of the curing and pressing is (1.15-1.3):

1.

6. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: In the preparation process of the composite carbon-carbon thermal insulation felt, the step of applying the phenolic resin liquid with a residual carbon rate of 46-50% comprises: using a pneumatic spray gun to apply the phenolic resin liquid with a residual carbon rate of 46-50% to the surface of the carbon-carbon thermal insulation felt substrate; wherein the viscosity of the phenolic resin liquid is ≥10000cps; the amount of the applied spray glue is 240-260g / m 2 ; And / or, the curing temperature is 210-230°C.

7. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: The carbonization procedure includes: A protective gas is introduced into the carbonization furnace, and the temperature begins to rise after 3 to 5 hours. The corresponding process curve is set, and the total time is 29 to 30 hours to heat up to 940 to 960°C, and then the temperature is kept at 940 to 960°C for 4 to 6 hours, and then the temperature is lowered to 60 to 80°C to stop carbonization.

8. The method for preparing the composite carbon-carbon thermal insulation hard felt according to claim 1, characterized in that: The high temperature treatment procedure includes: The high-temperature furnace is evacuated to a vacuum degree below -0.1Mpa, protective gas is introduced, and the corresponding process curve is set. It takes a total of 48 to 52 hours to heat up to 2250-2350°C, and then the temperature is kept at 2250-2350°C for 18 to 22 hours. Subsequently, the temperature is lowered to 60-80°C to stop the high-temperature treatment.

9. A composite carbon-carbon thermal insulation hard felt, characterized in that: The composite carbon-carbon thermal insulation hard felt comprises a reinforcing layer, a buffer layer and a carbon-carbon thermal insulation hard felt matrix stacked in sequence; and the composite carbon-carbon thermal insulation hard felt is prepared by the preparation method of the composite carbon-carbon thermal insulation hard felt described in any one of claims 1 to 8.

10. The composite carbon-carbon thermal insulation hard felt according to claim 9, characterized in that: The thickness of the reinforcement layer is 1 to 6.5 mm, the thickness of the buffer layer is 5 to 15 mm, and the thickness of the carbon-carbon thermal insulation hard felt matrix is ​​20 to 300 mm; And / or, the density of the reinforcement layer is 1.35-1.45 g / cm 3 The density of the buffer layer is 0.080~0.085g / cm 3 The density of carbon-carbon thermal insulation felt matrix is ​​0.15~0.17g / cm 3 ; And / or, the porosity of the reinforcement layer is 15-20%, the porosity of the buffer layer is 95-96%, and the porosity of the carbon-carbon thermal insulation hard felt matrix is ​​90-92%; And / or, the thermal conductivity of the buffer layer is 0.05-0.10 W / mk, and the thermal conductivity of the carbon-carbon thermal insulation hard felt matrix is ​​0.17-0.25 W / mk.

Images