Conductive glass fiber material with gradient resistance distribution as well as preparation method and application of conductive glass fiber material

Abstract

The invention relates to a conductive glass fiber material with gradient resistance distribution as well as a preparation method and application of the conductive glass fiber material. And the surface resistance of the conductive glass fiber material is in gradient change in the length direction. The conductive glass fiber material is conductive glass fiber filaments, fiber cloth woven by the conductive glass fiber filaments or conductive glass fiber cloth obtained by performing secondary processing on the fiber cloth woven by glass fibers. The conductive glass fiber material is preferably conductive glass fiber cloth obtained by carrying out secondary processing on fiber cloth woven by glass fibers. According to the conductive glass fiber material, gradient distribution of fabric surface resistance in the length direction can be achieved, so that the problem that heating is uneven due to the fact that electrode resistance is gradually increased due to the fact that an electrode is too long is solved, and the electric heating temperature distribution of a fabric area is even or tends to be even.

Description

Technical Field

[0001] The invention relates to the technical field of electric heating, and in particular to a conductive glass fiber material with gradient resistance distribution, a preparation method and application thereof. Background Art

[0002] In the fields of wind turbine blade deicing, aircraft deicing, etc., the deicing parts required in these fields are large in size or have a large length-to-width ratio. In order to meet the needs of these deicing applications, the length of the material required in the generally used electric heating deicing solution is relatively long, resulting in a particularly long electrode length; or, in order to ensure the widest possible heating area and the smallest possible electrode, the aspect ratio of the electrode is very large. In this case, the electrode resistance is very large and cannot be ignored, resulting in the voltage borne by the resistors in the heating area far from the current input and output ends being lower than that of the resistors in the heating area near the current input and output ends. Usually, the design of electrical components uses a constant voltage input, which will cause the power density of the heating area far from the current input and output ends to be lower than that of the heating area near the current input and output ends, and finally the temperature of the electric heating material after power is turned on will show a decreasing trend along the length direction. When the material length is long, the temperature difference between the head and tail of this material can reach hundreds of degrees Celsius, which seriously affects the application effect.

[0003] A production system and method for conductive fiber materials (CN116812618A) is another patent of the inventor of this application, which records that the prior art uses roll-to-roll CVD technology to prepare graphene-like carbon fiber materials, and uses a resistance detection module to detect and adjust the resistance value of the conductive fiber material in real time. Although this technology realizes the real-time detection of the resistance of the conductive material and the batch stable production of the conductive fiber material, it cannot solve the problem that the temperature of the heating area of ​​the fiber material close to the current input and output end is basically the same as the temperature of the heating area far from the current input and output end, and then realizes that the electric heating temperature of the entire heating area is basically the same. Summary of the invention

[0004] Based on the above problems, the present invention achieves uniform power density in the entire heating area by adjusting the resistance distribution, and finally achieves basically uniform electric heating temperature in the entire heating area, thereby overcoming the shortcomings and defects mentioned in the background technology.

[0005] To achieve the above object, the present application provides an invention point that the surface resistance of the conductive glass fiber material changes gradually in the length direction.

[0006] Furthermore, the conductive glass fiber material is conductive glass fiber yarn, fiber cloth woven from conductive glass fiber yarn, or conductive glass fiber cloth obtained by secondary processing of fiber cloth woven from glass fibers. The conductive glass fiber material is preferably conductive glass fiber cloth obtained by secondary processing of fiber cloth woven from glass fibers.

[0007] Furthermore, the conductive glass fiber material is provided with electrodes at both side edges along the length direction, the electrodes are provided with power contacts, and the surface resistance of the conductive glass fiber material decreases gradually along the length direction from close to the current input and output ends to far away from the current input and output ends.

[0008] Furthermore, when the conductive glass fiber material is electrically heated, its surface resistance is distributed in a gradient from the heating area close to the current input and output ends to the heating area far from the current input and output ends, so that the electrical heating temperature of the entire conductive glass fiber material is uniform or tends to be uniform.

[0009] Preferably, the surface resistance is distributed in a gradient along the length direction of the conductive glass fiber material and remains uniform along the width direction;

[0010] Preferably, the gradient distribution is a continuous linear gradient distribution or a step gradient distribution.

[0011] Furthermore, within the heating area of ​​the conductive glass fiber material, the sum of the surface resistance of the heating area far from the current input and output ends and the electrode resistance far from the current input and output ends is substantially consistent or tends to be consistent with the surface resistance of the heating area close to the current input and output ends.

[0012] Furthermore, the heating region includes glass fiber material and graphene. Specifically, the heating region includes a plurality of conductive glass fibers, and the conductive glass fibers include glass fibers and a graphene layer grown on the surface of the glass fibers.

[0013] Furthermore, the surface resistance gradient of the heating area is adjusted in a range of 10Ω / sq to 25000Ω / sq.

[0014] The present application does not make any specific limitation on glass fiber, which is a prior art. According to the requirements of the prior art, suitable glass fiber can be selected, for example, quartz glass fiber, alkali-free glass fiber, alkali-containing glass fiber, chemical-resistant glass fiber, alkali-resistant glass fiber, high-boron glass fiber, high-aluminum glass fiber or any other type of glass fiber. It is not the invention point of the present application and will not affect the invention point of the present application. Therefore, it can be selected according to the needs of the implementer.

[0015] Optionally, in the conductive glass fiber material, the electrode resistance close to the current input / output end is smaller than the electrode resistance far from the current input / output end, and the electrode resistance is gradient distributed along the length direction of the conductive glass fiber material and remains uniform along the width direction.

[0016] Another invention provided by the present application is a method for preparing a conductive glass fiber material with gradient resistance distribution, using a CVD method, comprising the following steps:

[0017] 1) Pretreatment;

[0018] 2) placing the glass fiber material into a processing device for growing graphene on the glass fiber material, and evacuating a process chamber of the processing device;

[0019] 3) Setting at least one of the temperature, pressure, carbon source flow rate, and the moving speed of the glass fiber material when growing graphene to increase or decrease over time; introducing a carbon source and a carrier gas to grow graphene on the surface of the glass fiber material, thereby obtaining a conductive glass fiber material with a gradient distribution of surface resistance.

[0020] Further, the processing equipment described in step 2) is a roll-to-roll equipment;

[0021] The carbon source in step 3) is selected from at least one of methane, ethane, propane, ethylene, acetylene, propylene, propyne, methanol, ethanol and acetone;

[0022] In step 3), the flow rate of the carrier gas is set to 20-5000 sccm, and the carrier gas is selected from hydrogen and / or argon.

[0023] Furthermore, the method further comprises step 4), wherein: electrodes are arranged along the length direction of the material obtained in step 3), so as to obtain a conductive glass fiber material with uniform electric heating temperature;

[0024] When configuring the electrodes in step 4), the area close to the current input and output terminals corresponds to the large surface resistance of the heating area, and the area far from the current input and output terminals corresponds to the small surface resistance of the heating area.

[0025] Furthermore, in step 3), at least one of the process parameters including temperature, pressure, carbon source flow rate, and moving speed is set to increase or decrease over time; when two or more process parameters are set to change over time at the same time, the multiple process parameters are set to increase or decrease in the same direction.

[0026] Furthermore, in step 3), any one of the process parameters, namely, temperature, pressure, carbon source flow rate, and moving speed, is set to increase or decrease over time, including at least one of the following situations:

[0027] K1: Set the temperature to change with time, so that the temperature increases or decreases within 700-1100°C, and keep the pressure, carbon source flow rate and moving speed unchanged;

[0028] K2: Set the carbon source flow rate to change over time, so that the carbon source flow rate increases or decreases within 50-5000sccm, keeping the pressure, temperature and moving speed unchanged;

[0029] K3: Set the pressure to change over time, so that the pressure increases or decreases within 100-5000 Pa, and keep the carbon source flow, temperature and moving speed unchanged;

[0030] K4: Set the moving speed to change with time, so that the moving speed increases or decreases within 5-200 mm / min, and keeps the carbon source flow, temperature and pressure unchanged.

[0031] Compared with the prior art, the present invention has the following advantages:

[0032] By using a conductive glass fiber material with a gradient resistance distribution of the present invention, the distribution gradient of the surface resistance in the length direction can be adjusted according to the length of the heating area required by the scene; the conductive glass fiber material of the present application can solve the gradient distribution of the fabric surface resistance along the length direction and the gradual increase of the electrode resistance caused by the excessive length of the electrode, which leads to different power density in the heating area and uneven heating, thereby achieving uniform or tending to uniform electric heating temperature distribution in the fabric area. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 Schematic diagram of heat generation by resistor;

[0034] Figure 2 Conductive glass fiber cloth structure diagram;

[0035] Figure 3 Figure 1. Conductive glass fiber material with uniform temperature distribution.

[0036] Figure 4 Diagram of conductive glass fiber material with continuous temperature gradient distribution;

[0037] Figure 5 Diagram of conductive glass fiber material with temperature step gradient distribution;

[0038] Figure 6 Actual picture of the conductive glass fiber cloth after adding electrodes.

[0039] Specific implementation method

[0040] In order to make the purpose, technical solution and advantages of the present application more clear, the present application is further described in detail below. However, it should be understood that the description here is only used to explain the present application and is not used to limit the scope of the present application.

[0041] Unless otherwise defined, all technical terms and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present application, and the terms used herein in the specification of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application. The reagents and instruments used herein are all commercially available, and the characterization means involved can refer to the relevant descriptions in the prior art, which will not be repeated herein.

[0042] In order to further understand the present application, the present application is further described in detail below in conjunction with the best embodiment.

[0043] Example 1

[0044] This embodiment provides a conductive glass fiber material in which the surface resistance changes gradually in the length direction.

[0045] Furthermore, the conductive glass fiber material can be conductive glass fiber yarn, or fiber cloth woven from conductive glass fiber yarn, or conductive glass fiber cloth obtained by secondary processing of fiber cloth woven from glass fibers. The conductive glass fiber material is preferably conductive glass fiber cloth obtained by secondary processing of fiber cloth woven from glass fibers.

[0046] Furthermore, the conductive glass fiber material is provided with electrodes at both side edges along the length direction, the electrodes are provided with power contacts, and the surface resistance of the conductive glass fiber material decreases gradually along the length direction from close to the current input and output end to far away from the current input and output end.

[0047] A conductive glass fiber material with gradient resistance distribution, wherein the conductive glass fiber material is divided into a heating area close to a current input and output end and a heating area far from the current input and output end along the length direction, and the heating area close to the current input and output end is provided with a power supply access point;

[0048] In the conductive glass fiber material, the surface resistance of the heating area close to the current input and output terminals is greater than the surface resistance of the heating area far from the current input and output terminals.

[0049] As a further preferred embodiment, the surface resistance of the conductive glass fiber material is distributed in a gradient from the heating area close to the current input and output ends to the heating area far from the current input and output ends, so that the electric heating temperature of the entire conductive glass fiber material is uniform or tends to be uniform, such as Figure 3 shown.

[0050] As a further preferred embodiment, the surface resistance of the heating area close to the current input and output terminals decreases in sequence to the surface resistance of the heating area far from the current input and output terminals;

[0051] The surface resistance is distributed in a gradient along the length direction of the heated area of ​​the conductive glass fiber material and remains uniform along the width direction;

[0052] The gradient distribution is a continuous linear gradient distribution or a step-type gradient distribution.

[0053] As a further preferred embodiment, within the heating area of ​​the conductive glass fiber material, the sum of the surface resistance of the heating area far away from the current input and output ends and the electrode resistance far away from the current input and output ends is basically consistent or tends to be consistent with the surface resistance of the heating area close to the current input and output ends.

[0054] It is mentioned in the background technology that due to the demand for the electrodes configured in the heating technology, the length of the electrodes is particularly long, or the aspect ratio of the electrodes is very large. In this case, if the heating temperature of the heating area of ​​the conductive glass fiber material is to be basically uniform, then the composition of the resistance distribution near the current input and output ends and far from the current input and output ends is different: near the current input and output ends, its actual resistance is the resistance of the heating area of ​​the conductive glass fiber material near the electrode input and output ends; far from the current input and output ends, its actual resistance is the series resistance composed of the electrode resistance and the resistance of the heating area far from the current input and output ends. The heating principle in the prior art is as follows: Figure 1 As shown in the figure, if the resistance of the conductive glass fiber material in the heating area of ​​the conductive glass fiber cloth is consistent, then press Figure 2 The material composition is shown in Figure 1, and its resistance distribution can be considered as follows: Figure 1 As shown. Then the voltage relationship of the parallel circuit is:

[0055] U=U1=U2+2U 电阻

[0056] U2=U3+2U 电阻

[0057] U3=U4+2U 电阻 ......

[0059] U n =U n-1 +2U 电阻

[0060] Based on the above formula, the voltage relationship is U1=U>U2>U3>.....>U n-2 >U n-1 >U n ,

[0061] Therefore, when the resistors are uniform as in the prior art, the heat generation relationship is:

[0062] Q1>Q2>Q3>...>Qn .

[0063] If the heat generated by each resistor is required to be uniform, then the resistor must meet certain requirements. The specific calculation is as follows:

[0064] Heat generated by the nth resistor: ,

[0065] Heat generated by the n-1th resistor:

[0066] Thanks to Q n =Q n-1 ,therefore Then the resistance of the n-1th resistor is:

[0067]

[0068] Similarly, the heat generated by the n-1th resistor is:

[0069]

[0070] Heat generated by the n-2nd resistor:

[0071] Since the heat generated by the n-1th resistor is basically the same as the heat generated by the n-2th resistor, the resistance of the n-2th resistor is

[0072]

[0073] By analogy, the resistance of the first resistor is:

[0074] From the above formula, we can see that the conditions that need to be met for heating are: R 布1 >R 布2 >R 布3 >......>R 布n-1 >R 布n

[0075] Therefore, through the method of adjusting the surface resistance in the present application, the resistance of the heating area close to the current input and output ends is larger, and the resistance of the heating area far from the current input and output ends is smaller, ensuring that the resistance of the heating area close to the current input and output ends is basically consistent with the sum of the resistance of the heating area far from the current input and output ends and the electrode resistance far from the current input and output ends, thereby achieving the consistency of the power density of the entire heating area, and finally achieving the electric heating temperature of the entire heating area is basically consistent, that is:

[0076] 1. For continuous linear gradient: R 布1 ≈R 布2 +2R 电极 ≈R布3 +4R 电极 ≈..........≈R 布n +(n-1)·2R 电极 , when the input current I is constant, U1≈U2≈U3≈..........≈Un, so the heat generation relationship is: Q1≈Q2≈Q3≈...≈Q n .

[0077] 2. For step distribution gradient: R 布11 ≈R 布21 +2R 布11布21之间电极 =R 布31 +2R 布11布31之间电极 ...,

[0078] Among them, R 布11～R布1n Belongs to the first step, R 布21～R布2n Belongs to the second level...

[0079] As a further preferred embodiment, the heating region includes glass fibers and graphene. Specifically, the heating region includes a plurality of conductive glass fibers. The conductive glass fibers include glass fibers and a graphene layer grown on the periphery of the glass fibers.

[0080] Glass fiber (original name: glass fiber fabric) is an inorganic non-metallic material with excellent performance. It has a wide variety of types. Its advantages are good insulation, strong heat resistance, good corrosion resistance, and high mechanical strength, but its disadvantages are brittleness and poor wear resistance. Glass fiber is usually used as a reinforcing material in composite materials, electrical insulation materials and thermal insulation materials, circuit substrates and other fields of the national economy.

[0081] When graphene-like materials are compounded with glass fibers through chemical vapor deposition (CVD), a new type of conductive fiber will be produced, and its conductivity will be greatly improved.

[0082] The surface resistance of the heating area is varied by varying the thickness of the graphene layer or by varying the density of the conductive glass fiber.

[0083] The present application does not make any specific limitation on glass fiber, which is a prior art. According to the requirements of the prior art, suitable glass fiber can be selected, for example, quartz glass fiber, alkali-free glass fiber, alkali-containing glass fiber, chemical-resistant glass fiber, alkali-resistant glass fiber, high-boron glass fiber, high-aluminum glass fiber or any other type of glass fiber. It is not the invention point of the present application and will not affect the invention point of the present application. Therefore, it can be selected according to the needs of the implementer.

[0084] As a further preferred embodiment, the surface resistance gradient adjustment range is 10Ω / sq to 25000Ω / sq, and the surface resistance adjustment can start from any value within the range and end at any value, and of course it can also start from 10Ω / sq and end at 25000Ω / sq within the range; for example, the aforementioned arbitrary value can be 10Ω / sq, 50Ω / sq, 100Ω / sq, 150Ω / sq, 200Ω / sq, 250Ω / sq, 300Ω / sq, 350Ω / sq q, 400Ω / sq, 450Ω / sq, 500Ω / sq, 550Ω / sq, 600Ω / sq, 650Ω / sq, 700Ω / sq, 750Ω / sq, 800Ω / sq, 850Ω / sq, 900Ω / sq, 950Ω / sq, 1000Ω / sq, 2000Ω / sq, 3000Ω / sq, 4000Ω / sq, 5000Ω / sq, 10000Ω / sq, 15000Ω / sq, 20000Ω / sq, 22 000Ω / sq, 25000Ω / sq, etc. The start and end intervals can be 10Ω / sq~25000Ω / sq, 10Ω / sq~22000Ω / sq, 10Ω / sq~20000Ω / sq, 10Ω / sq~18000Ω / sq, 50~10000Ω / sq, 50~9500Ω / sq, 50~9000Ω / sq, 50~8500Ω / sq, 50~8000Ω / sq, 50~7500Ω / sq, 50~ 7000Ωsq, 50-6500Ω / sq, 500-15000Ω / sq, 500~14000Ω / sq, 1000-10000Ω / sq, 10000~20000Ω / sq, 500~22000Ω / sq, 10000~25000Ω / sq, 10000~13000Ω / sq, 50~350Ω / sq, 50~300Ω / sq, etc. can be used for gradient distribution in any interval. In practice, appropriate selection can be made according to needs.

[0085] The material of the electrode is not specifically limited in the present invention. Strictly speaking, any material that can achieve the desired effect can be a candidate.

[0086] Example 2

[0087] Based on Example 1, a conductive glass fiber with uniform heat generation is used in the preparation of an electric heating material; the conductive glass fiber includes any one of the conductive glass fiber materials described above, or includes a conductive glass fiber material prepared by any one of the methods described above.

[0088] Electric heating materials include those used for heating, baking, physical therapy, drying, waterproofing, anti-fogging, anti-icing, etc.

[0089] Example 3

[0090] According to the content of this application, the conductive glass fiber material with gradient resistance distribution of Example 1 is prepared by a CVD method, comprising the following steps:

[0091] 1) Pretreatment;

[0092] 2) placing the glass fiber material into a processing device for growing graphene on the glass fiber material, and evacuating a process chamber of the processing device;

[0093] 3) Setting at least one parameter among the temperature, pressure, carbon source flow rate, and moving speed of the glass fiber material when growing graphene to increase or decrease over time; introducing a carbon source and a carrier gas to grow graphene on the surface of the glass fiber material, thereby obtaining a conductive glass fiber material with a gradient distribution of surface resistance.

[0094] As a further preferred embodiment, the method further comprises step 4),

[0095] Step 4): Arrange electrodes along the length direction of the material obtained in step 3), so as to obtain a conductive glass fiber material with uniform electric heating temperature;

[0096] When configuring the electrodes in step 4), the area of ​​the heating layer close to the current input and output terminals corresponds to the area of ​​large surface resistance of the heating layer, and the area of ​​the heating layer far from the current input and output terminals corresponds to the area of ​​small surface resistance of the heating layer.

[0097] The moving speed may be the winding speed of a reel device or the walking speed of a paving device.

[0098] As a processing equipment, roll-to-roll CVD equipment can realize program control setting of process parameters. The general process is:

[0099] S1: The glass fiber material is surface pretreated to remove the surface wetting agent or coupling agent to expose the original surface of the glass fiber material;

[0100] S2: The glass fiber material roll is placed on the unwinding shaft of the unwinding chamber of the roll-to-roll CVD device, and the free end of the glass fiber material roll passes through the process chamber of the roll-to-roll CVD device and then enters the winding chamber of the roll-to-roll CVD device and is connected to the winding shaft of the winding chamber;

[0101] S3: The process chamber of the roll-to-roll CVD equipment is evacuated to 1×10 -3 Pa; the temperature is adjusted incrementally / decrementally, and the temperature is kept warm;

[0102] S4: The pressure is adjusted incrementally / decreasingly;

[0103] S5: Start the carbon source and carrier gas to be introduced into the process chamber, and adjust the carbon source flow rate by increasing / decreasing to perform gas phase growth of graphene film;

[0104] S6: Turn on the winding device of the roll-to-roll CVD equipment, start winding the glass fiber material, and adjust the winding speed by increasing / decreasing;

[0105] S7: adjusting at least one of the process parameters in steps S3, S4, S5 and S6 by increasing / decreasing. If two or more process parameters change with time at the same time, the process parameters are adjusted by increasing / decreasing in the same direction. After a certain period of time, a glass fiber material with a gradient distribution of surface resistance can be obtained.

[0106] S8: Repeat step S7 until the glass fiber material loaded on the unwinding shaft is used up, thereby obtaining a whole roll of graphene conductive glass fiber material.

[0107] S9: configuring electrodes on the graphene conductive glass fiber material obtained in step S8, that is, obtaining a graphene conductive glass fiber material with electrodes and a surface resistance gradient distribution, such as Figure 6 shown.

[0108] Preferably, the carbon source is selected from at least one of methane, ethane, propane, ethylene, acetylene, propylene, propyne, methanol, ethanol and acetone;

[0109] Preferably, the flow rate of the carrier gas is set to 20-5000 sccm, and the carrier gas is selected from hydrogen and / or argon;

[0110] The flow rate of the carrier gas is set to 20-5000sccm, for example, 20, 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3500, 4000, 4500, 5000sccm or any value between any two values.

[0111] As a further preferred embodiment, in the step 3), at least one of the process parameters, namely, temperature, pressure, carbon source flow rate, and moving speed, is set to increase or decrease over time;

[0112] When two or more process parameters are set to change with time simultaneously, the multiple process parameters are set to change in the same direction, either increasing or decreasing.

[0113] As a further preferred embodiment, in the step 3), any one of the process parameters of temperature, pressure, carbon source flow rate, and moving speed is set to increase or decrease over time, including at least one of the following situations:

[0114] K1: If the temperature changes with time, the temperature increases or decreases within the range of 700-1100°C, while keeping the pressure, carbon source flow rate and moving speed unchanged. For example, the temperature can be increased at a uniform speed, at a variable speed, in a uniform step-by-step manner (such as increasing the same temperature each time within the same period of time), or in a non-uniform step-by-step manner during the increasing process. Each completed structural unit can be increased in an increasing manner. The temperature increase can also start and end at any segment within the range of 700-1100°C. Of course, it can also start at 700°C and end at 1100°C within the range, or start at 700°C and end at any segment within the range, or start at any segment and end at 1100°C. It can increase sequentially within the selected area. For example, each increase of 50°C is a gradient, such as selecting the start and end segments from 700, 750, 800, 850, 900, 950, 1000, 1050, 1100°C or any number between any two values; for example, from 700°C at the beginning to 1100°C at the end is a unit, then in this unit, the temperature can be raised from 700°C to 1100°C at a uniform speed, or it can be changed in steps from 700°C for 10 minutes, 800°C for 18 minutes, 900°C for 28 minutes, 1000°C for 12 minutes, and 1100°C for 10 minutes. It can be selected according to the application scenario.

[0115] K2: If the carbon source flow rate changes with time, the carbon source flow rate is adjusted to increase or decrease within 50 to 5000 sccm, keeping the pressure, temperature and moving speed unchanged. For example, the flow rate is increasing in the same process as the temperature, including uniform increase, variable increase, uniform step-by-step increase and non-uniform step-by-step increase. It can also start increasing at any segment and end increasing at any segment, for example, from 50, 100, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200 00, 2300, 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3500, 4000, 4500, 5000sccm or any value between any two values ​​to select the start and end segments; for example, from 100sccm at the beginning to 5000sccm at the end is a unit, then in this unit, you can increase from 100sccm to 5000sccm at a uniform speed, or you can change in steps from 100sccm for 10 minutes, 500sccm for 15 minutes, 1000sccm for 20 minutes, 3000sccm for 10 minutes, 5000sccm for 10 minutes, you can choose according to the application scenario.

[0116] K3: If the pressure changes with time, the pressure is adjusted to increase or decrease within 100-5000Pa, keeping the carbon source flow, temperature and moving speed unchanged. For example, the increasing method is the same as the increasing method of temperature, including uniform increasing speed, variable increasing speed, uniform step-by-step increasing and non-uniform step-by-step increasing. It can also start increasing at any segment and end increasing at any segment, for example, from 100, 200, 300, 400, 500, 600, 700, 800, 900, 1000, 1100, 1200, 1300, 1400, 1500, 1600, 1700, 1800, 1900, 2000, 2100, 2200, 2300, The start and end sections can be selected from 2400, 2500, 2600, 2700, 2800, 2900, 3000, 3100, 3200, 3300, 3500, 4000, 4500, 5000Pa or any value between any two values. For example, a unit is 200Pa at the beginning and 5000Pa at the end. In this unit, the pressure can be increased from 200Pa to 5000Pa at a uniform speed, or it can be changed in steps from 200Pa for 5 minutes, 1000Pa for 10 minutes, 2000Pa for 100 minutes, 3000Pa for 50 minutes, and 5000Pa for 10 minutes. It can be selected according to the application scenario.

[0117] K4: If the moving speed changes with time, the moving speed is adjusted to increase or decrease within 5 to 200 mm / min, keeping the carbon source flow, temperature and pressure unchanged. For example, the increasing methods include uniform speed increase, uniform variable speed increase, variable speed increase, uniform step-by-step increase and non-uniform step-by-step increase, such as 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 195 , 200mm / min or any value between any two values ​​to select the start and end segments. For example, from 5mm / min at the beginning to 150mm / min at the end is a unit. Then in this unit, you can accelerate from 5mm / min to 150mm / min at a uniform speed, from 5mm / min to 150mm / min at a uniform speed, from 5mm / min to 150mm / min at a variable speed, or from 5mm / min to 150mm / min in a step-by-step manner from 5mm / min for 10 minutes, 15mm / min for 15 minutes, 50mm / min for 20 minutes, ... to 150mm / min for 10 minutes. You can choose according to the application scenario.

[0118] Preferably, if the moving speed varies with time, the moving speed is adjusted to increase or decrease within 5 to 200 mm / min, while keeping the carbon source flow rate, temperature and pressure unchanged.

[0119] It should be noted that the change adjustment can be incremental or decremental, and can be uniform speed, variable speed or step-by-step, etc. There is no restriction here. Ultimately, it is necessary to ensure that the surface resistance of the heating area close to the current input and output ends is greater than the surface resistance of the heating area far away from the current input and output ends according to the scene requirements.

[0120] The time is related to the length of the conductive glass fiber material that needs to be processed in the application scenario, and is usually 5 to 1500 minutes. In special cases, such as extremely short or extremely long times, values ​​beyond the range of this application can also be achieved.

[0121] Example 4

[0122] According to the content of this application, the conductive glass fiber material with gradient resistance distribution of this application is specifically described. If no specific experimental steps or conditions are specified in the embodiments, the conventional experimental steps or conditions described in the literature in this field can be used. If the manufacturer of the reagents or instruments used is not specified, they are all conventional reagent products that can be purchased commercially.

[0123] The present invention is further described in detail below in conjunction with specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention.

[0124] The present invention specifically uses quartz glass fiber material as the conductive glass fiber material in the test examples and comparative examples. Other fiber materials can achieve the effects of the present invention in the present invention. Due to space limitations, other glass fiber materials are not illustrated one by one.

[0125] 1. Continuous linear gradient distribution of surface resistance

[0126] Test Example 1

[0127] The winding speed can be set to vary over time.

[0128] The graphene conductive glass fiber cloth is prepared by the following steps:

[0129] 1) The quartz glass fiber cloth is surface pretreated to remove the surface wetting agent or coupling agent to expose the original surface of the glass fiber cloth;

[0130] 2) The quartz glass fiber cloth roll is placed on the unwinding shaft of the unwinding chamber of the roll-to-roll CVD device, and the free end of the quartz glass fiber cloth roll passes through the process chamber of the roll-to-roll CVD device and enters the winding chamber of the roll-to-roll CVD device, and is connected to the winding shaft of the winding chamber;

[0131] 3) Evacuate the process chamber of the roll-to-roll CVD equipment to 1×10 -3 Pa, the process temperature was set to 1000°C, and the temperature was kept constant;

[0132] 4) starting the carbon source methane and the carrier gas hydrogen to be introduced into the process chamber, the methane flow rate is set to 1000 sccm, the hydrogen flow rate is set to 3000 sccm, and the target pressure is set to 1000 Pa to perform gas phase growth of the graphene film;

[0133] 5) The winding device of the roll-to-roll CVD equipment is turned on, and the winding speed of the glass fiber cloth is accelerated from 5 mm / min to 200 mm / min for 200 min to obtain a graphene conductive glass fiber cloth, and an electrode is arranged on the graphene conductive glass fiber cloth.

[0134] Test results: The surface resistance of the graphene conductive glass fiber cloth obtained is distributed from 1056Ω / sq to 19860Ω / sq, with a length of 20.5m, and the surface resistance is evenly and continuously distributed.

[0135] The test results show that the area with a surface resistance distribution of 19860Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 1056Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is powered on for heating with a voltage of 240VDC. The temperature of the area close to the current input and output terminals is 56.6℃, and the temperature of the area far away from the current input and output terminals is 55.7℃. The electric heating temperatures are basically the same.

[0136] Test Example 2

[0137] The temperature can be set to change with time. In 200 minutes, the temperature is increased from 950℃ to 1100℃. The winding speed is fixed at 20mm / min. Other test conditions are consistent with those in Test Example 1, such as Figure 4 shown.

[0138] Test results: The surface resistance of the conductive glass fiber material is uniformly and continuously reduced from 19969Ω / sq to 995Ω / sq.

[0139] The test results show that the area with a surface resistance distribution of 19969Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 995Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is heated by electricity, and the voltage is 240VDC. The temperature of the area near the current input and output terminals is 57.7℃. The temperature of the area far away from the current input and output terminals is 55.0℃, and the electric heating temperature is basically the same.

[0140] Test Example 3

[0141] The carbon source flow rate can be set to a flow rate that changes with time. Within 200 minutes, the carbon source flow rate increases from 50 sccm to 5000 sccm. The winding speed is fixedly set to 102.5 mm / min. Ethylene is used as the carbon source. Other experimental conditions are consistent with Experimental Example 1.

[0142] Test results: The surface resistance of the conductive glass fiber material is uniformly and continuously reduced from 19337Ω / sq ​​to 1048Ω / sq.

[0143] The test results show that the area with a surface resistance distribution of 19337Ω / sq ​​is close to the current input and output terminals, and the area with a resistance distribution of 1048Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is heated by electricity, and the voltage is 240VDC. The temperature of the area near the current input and output terminals is 57.2℃. The temperature of the area far away from the current input and output terminals is 56.7℃, and the electric heating temperature is basically the same.

[0144] Test Example 4

[0145] The pressure can be set to a pressure that changes with time. Within 200 minutes, the pressure increases from 100Pa to 5000Pa. The winding speed is set to 102.5mm / min. Ethylene is the carbon source. Other test conditions are consistent with Test Example 1.

[0146] Test results: The surface resistance of the conductive glass fiber material is uniformly and continuously reduced from 20649Ω / sq to 1123Ω / sq.

[0147] The test results show that the area with a surface resistance distribution of 20649Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 1123Ω / sq is far away from the current input and output terminals. When the graphene conductive glass fiber cloth is heated by electricity, the voltage is 240VDC, and the temperature of the area close to the current input and output terminals is 56.2℃. The temperature of the area far away from the current input and output terminals is 56.7℃, and the electric heating temperatures are basically the same.

[0148] Test Example 5

[0149] Process condition settings: temperature was set to 950°C, carbon source was acetylene, flow rate was 300 sccm, hydrogen flow rate was 1000 sccm, pressure was 1500 Pa, winding speed was increased from 5 mm / min to 200 mm / min within 200 min, other test conditions were consistent with test example 1.

[0150] Test results: The surface resistance of the conductive glass fiber material increased uniformly and continuously from 983Ω / sq to 19582Ω / sq.

[0151] The test results show that the area with a surface resistance distribution of 19582Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 983Ω / sq is far away from the current input and output terminals. When the graphene conductive glass fiber cloth is heated by electricity, the voltage is 240VDC, and the temperature of the area close to the current input and output terminals is 56.8℃. The temperature of the area far away from the current input and output terminals is 57.2℃, and the electric heating temperatures are basically the same.

[0152] Test Example 6

[0153] Process condition settings: temperature set to 900°C, carbon source is acetylene, flow rate is 500sccm, hydrogen flow rate is 1000sccm, pressure is 1500Pa, within 200min, winding speed is accelerated from 5mm / min to 200mm / min, other test conditions are consistent with test example 1.

[0154] Test results: The surface resistance of the conductive glass fiber material increased uniformly and continuously from 1074Ω / sq to 21230Ω / sq.

[0155] The test results show that the area with a surface resistance distribution of 21230Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 1074Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is heated by electricity, and the voltage is 240VDC. The temperature of the area near the current input and output terminals is 55.6℃. The temperature of the area far away from the current input and output terminals is 56.4℃, and the electric heating temperature is basically the same.

[0156] 2. Surface resistance step gradient distribution

[0157] Test Example 7

[0158] The winding speed is set to a speed that changes with steps. Within 280 minutes, the winding speed is maintained at 5 mm / min. After reaching the time, the winding speed is quickly adjusted to 50 mm / min and maintained for 28 minutes. After reaching the time, the winding speed is quickly adjusted to 100 mm / min and maintained for 14 minutes. After reaching the time, the winding speed is quickly adjusted to 200 mm / min and maintained for 7 minutes. Other test conditions are consistent with Test Example 1.

[0159] Test results: The surface resistance distribution of the material is 1097Ω / sq, with a length of 1.4 meters; the subsequent section is 2535Ω / sq, with a length of 1.4 meters; the subsequent section is 5002Ω / sq, with a length of 1.4 meters; the subsequent section is 20964Ω / sq, with a length of 1.4 meters.

[0160] The test results show that the area with a surface resistance distribution of 20964Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 1097Ω / sq ​​is far away from the current input and output terminals. The graphene conductive glass fiber cloth is powered on for heating, and the voltage is 240VDC. The average temperature distribution of the four sections is that the temperature of the area close to the current input and output terminals is 56.3℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 5002Ω / sq is 55.4℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 2535Ω / sq is 57.5℃, and the temperature of the area far away from the current input and output terminals is 55.7℃.

[0161] Test Example 8

[0162] The temperature can be set to change with steps, the winding speed is set to 15mm / min, and the process chamber of the roll-to-roll CVD equipment has 4 temperature controllers. The process temperature of the first temperature controller is raised to 700℃ and maintained for 94min; after the time is reached, the second temperature controller is raised to 800℃ and maintained for 94min; after the time is reached, the third temperature controller is raised to 900℃ and maintained for 94min; after the time is reached, the fourth temperature controller is raised to 1000℃ and maintained for 94min; other test conditions are consistent with test example 1, such as Figure 5shown.

[0163] Test results: The surface resistance distribution of the material is 10026Ω / sq, with a length of 1.41 meters; the subsequent section is 5101Ω / sq, with a length of 1.41 meters; the subsequent section is 1013Ω / sq, with a length of 1.41 meters; the subsequent section is 510Ω / sq, with a length of 1.41 meters.

[0164] The test results show that the area with a surface resistance distribution of 10026Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 500Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is powered on to heat the graphene conductive glass fiber cloth, with a voltage of 240VDC. The average temperature distribution test of the four sections shows that the temperature of the area close to the current input and output terminals is 104.4℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 5101Ω / sq is 100.8℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 1013Ω / sq is 102.4℃, and the temperature of the area far away from the current input and output terminals is 105.9℃.

[0165] Test Example 9

[0166] The carbon source flow rate can be set to a flow rate that changes with steps, and the winding speed is set to 15mm / min. Within 94 minutes, the flow rate of the carbon source methane is maintained at 700sccm; after the arrival time, the flow rate of the carbon source methane is quickly adjusted to 1500sccm and maintained for 94 minutes; after the arrival time, the flow rate of the carbon source methane is quickly adjusted to 3000sccm and maintained for 94 minutes; after the arrival time, the flow rate of the carbon source methane is quickly adjusted to 5000sccm and maintained for 94mim; other experimental conditions are consistent with Experimental Example 1.

[0167] Test results: The surface resistance distribution of the material is 10132Ω / sq, with a length of 1.41 meters; the subsequent section is 3087Ω / sq, with a length of 1.41 meters; the subsequent section is 1106Ω / sq, with a length of 1.41 meters; the subsequent section is 496Ω / sq, with a length of 1.41 meters.

[0168] The test results show that the area with a surface resistance distribution of 10132Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 496Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is powered on to heat the graphene conductive glass fiber cloth, and the voltage is 240VDC. The average temperature of the four sections is tested. The temperature of the area close to the current input and output terminals is 115.0℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 3087Ω / sq ​​is 114.4℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 1106Ω / sq is 110.3℃, and the temperature of the area far away from the current input and output terminals is 112.7℃.

[0169] Test Example 10

[0170] The pressure can be set to a pressure that changes in steps. The winding speed is set to 15 mm / min. The pressure is maintained at 100 Pa within 94 minutes. After the time is reached, the pressure rises rapidly to 500 Pa and is maintained for 94 minutes. After the time is reached, the pressure rises rapidly to 2000 Pa and is maintained for 94 minutes. After the time is reached, the pressure rises rapidly to 5000 Pa and is maintained for 94 minutes. The other test conditions are consistent with those in Test Example 1.

[0171] Test results: The surface resistance distribution of the material is 10179Ω / sq, with a length of 1.41 meters; the subsequent section is 2975Ω / sq, with a length of 1.41 meters; the subsequent section is 973Ω / sq, with a length of 1.41 meters; the subsequent section is 496Ω / sq, with a length of 1.41 meters.

[0172] The test results show that the area with a surface resistance distribution of 10179Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 496Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is powered on to heat the graphene conductive glass fiber cloth, with a voltage of 240VDC. The average temperature distribution test of the four sections shows that the temperature of the area close to the current input and output terminals is 112.2℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 2975 ohms is 114.6℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 973 ohms is 110.8℃, and the temperature of the area far away from the current input and output terminals is 115.2℃.

[0173] Test Example 11

[0174] Process conditions were set as follows: the temperature was set to 800°C, the carbon source was ethylene, the flow rate was 4500sccm, the hydrogen flow rate was 4000sccm, the pressure was 3500Pa, and the winding speed was set to a speed that changed in steps. Within 280 minutes, the winding speed was maintained at 5mm / min. After the time was reached, the winding speed was quickly adjusted to 50mm / min and maintained for 28 minutes. After the time was reached, the winding speed was quickly adjusted to 100mm / min and maintained for 14 minutes. After the time was reached, the winding speed was quickly adjusted to 200mm / min and maintained for 7 minutes. Other experimental conditions were consistent with those in Experimental Example 1.

[0175] Test results: The surface resistance distribution of the material is 505Ω / sq, and the length is 1.4 meters; the subsequent section is 1036Ω / sq, and the length is 1.4 meters; the subsequent section is 3023Ω / sq, and the length is 1.4 meters; the subsequent section is 9943Ω / sq, and the length is 1.4 meters.

[0176] The test results show that the area with a surface resistance distribution of 9943Ω / sq is close to the current input and output terminals, and the area with a resistance distribution of 505Ω / sq is far away from the current input and output terminals. The graphene conductive glass fiber cloth is powered on to heat the graphene conductive glass fiber cloth, with a voltage of 240VDC. The average temperature distribution test of the four sections shows that the temperature of the area close to the current input and output terminals is 114.8℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 3023 ohms is 111.4℃, the heating temperature of the graphene conductive glass fiber cloth with a surface resistance of 1036 ohms is 116.5℃, and the temperature of the area far away from the current input and output terminals is 117.1℃.

[0177] Comparative Example 1

[0178] The winding speed was set to 102.5 mm / min, the time was 200 min, and the other test conditions were consistent with those in Test Example 1.

[0179] Test results: The graphene conductive glass fiber cloth obtained has a uniform and continuous distribution surface resistance of 4977Ω / sq ​​and a length of 20.5m.

[0180] The test results show that when the graphene conductive glass fiber cloth is heated by electricity, the voltage is 240VDC. The temperature of the heating area close to the current input and output ends is 60.0℃, and the temperature of the heating area far away from the current input and output ends is 37.7℃.

[0181] Comparative Example 2

[0182] The winding speed was set to 15 mm / min, the time was 376 min, and the other test conditions were consistent with those in Test Example 1.

[0183] Test results: The graphene conductive glass fiber cloth obtained has a uniform and continuous distribution surface resistance of 1001Ω / sq and a length of 5.64m.

[0184] The test results show that when the graphene conductive glass fiber cloth is heated by electricity, the voltage is 240VDC. The temperature of the heating area close to the current input and output ends is 35.1℃, and the temperature of the heating area far from the current input and output ends is 24.9℃.

[0185] The graphene conductive glass fiber cloth has a resistance gradient distribution, so that the electric heating temperature is basically consistent or tends to be consistent; while the resistance in the prior art is evenly distributed, resulting in a large temperature difference.

[0186] In the application scenario of the conductive glass fiber material with gradient resistance distribution of the present invention, the gradient distribution of the surface resistance of the heating area of ​​the glass fiber material is set according to the required length of the conductive glass fiber material. The gradient distribution of the surface resistance of the heating area within a specific time can also be repeated based on the whole roll of conductive glass fiber material until the whole roll of fiber material is used up. Therefore, the present invention does not repeat the preparation process here.

[0187] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A conductive glass fiber material with gradient resistance distribution, characterized in that: The surface resistance of the conductive glass fiber material changes gradually in the length direction.

2. The conductive glass fiber material according to claim 1, characterized in that: The conductive glass fiber material is conductive glass fiber yarn, fiber cloth woven from conductive glass fiber yarn, or conductive glass fiber cloth obtained by secondary processing of fiber cloth woven from glass fibers. The conductive glass fiber material is preferably conductive glass fiber cloth obtained by secondary processing of fiber cloth woven from glass fibers.

3. The conductive glass fiber material according to claim 1 or 2, characterized in that: The conductive glass fiber material is also provided with electrodes at both side edges along the length direction, and the electrodes are provided with power contacts. The surface resistance of the conductive glass fiber material decreases gradually along the length direction from close to the current input and output end to far away from the current input and output end.

4. The conductive glass fiber material according to claim 3, characterized in that: When the conductive glass fiber material is electrically heated, its surface resistance is distributed in a gradient from the heating area close to the current input and output ends to the heating area far from the current input and output ends, so that the electric heating temperature of the entire conductive glass fiber material is uniform or tends to be uniform; preferably, the surface resistance is distributed in a gradient along the length direction of the conductive glass fiber material and remains uniform along the width direction; the gradient distribution is preferably a continuous linear gradient distribution or a step gradient distribution.

5. The conductive glass fiber material according to claim 4, characterized in that: In the heating area of ​​the conductive glass fiber material, the sum of the surface resistance of the heating area far away from the current input and output ends and the electrode resistance far away from the current input and output ends is basically consistent with or tends to be consistent with the surface resistance of the heating area close to the current input and output ends; preferably, the heating area of ​​the conductive glass fiber material includes glass fiber material and graphene, specifically, the heating area includes a plurality of conductive glass fibers, and the conductive glass fibers include glass fibers and a graphene layer grown on the periphery of the glass fibers.

6. The conductive glass fiber material according to claim 1, characterized in that: The surface resistance gradient of the heating area is adjusted in a range of 10Ω / sq to 25000Ω / sq.

7. A method for preparing a conductive glass fiber material with gradient resistance distribution, characterized in that: The CVD method includes the following steps: 1) Pretreatment; 2) placing the glass fiber material in a processing device for growing graphene on the glass fiber material, and evacuating a process chamber of the processing device; 3) setting at least one of the process parameters of temperature, pressure, carbon source flow rate, and moving speed of the glass fiber material when growing graphene to increase or decrease over time; A carbon source and a carrier gas are introduced to grow graphene on the surface of the glass fiber material, thereby obtaining a conductive glass fiber material with a gradient distribution of surface resistance.

8. The preparation method according to claim 7, characterized in that: The processing equipment described in step 2) is a roll-to-roll equipment; The carbon source in step 3) is selected from at least one of methane, ethane, propane, ethylene, acetylene, propylene, propyne, methanol, ethanol and acetone; In step 3), the flow rate of the carrier gas is set to 20-5000 sccm, and the carrier gas is selected from hydrogen and / or argon.

9. The preparation method according to claim 7 or 8, characterized in that: The method further includes step 4), wherein electrodes are arranged along the length direction of the material obtained in step 3), so as to obtain a conductive glass fiber material with uniform electric heating temperature; when the electrodes are arranged in step 4), the area close to the current input and output terminals corresponds to a large surface resistance of the heating area, and the area far from the current input and output terminals corresponds to a small surface resistance of the heating area.

10. The preparation method according to claim 7, characterized in that: In step 3), at least one of the process parameters, namely, temperature, pressure, carbon source flow rate, and moving speed, is set to increase or decrease over time; When two or more process parameters are set to change with time at the same time, the multiple process parameters are set to change in the same direction, either increasing or decreasing. Preferably, in step 3), any one of the process parameters, namely, temperature, pressure, carbon source flow rate, and moving speed, is set to increase or decrease over time, including at least one of the following situations: K1: Set the temperature to change with time, so that the temperature increases or decreases within 700-1100°C, and keep the pressure, carbon source flow rate and moving speed unchanged; K2: Set the carbon source flow rate to change over time, so that the carbon source flow rate increases or decreases within 50-5000sccm, keeping the pressure, temperature and moving speed unchanged; K3: Set the pressure to change over time, so that the pressure increases or decreases within 100-5000 Pa, and keep the carbon source flow, temperature and moving speed unchanged; K4: Set the moving speed to change with time, so that the moving speed increases or decreases within 5-200 mm / min, and keeps the carbon source flow, temperature and pressure unchanged.

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