TWM622074U - Water washing device for carbon fiber precursor - Google Patents

Abstract

A water washing device for carbon fiber precursor is provided. The water washing device is set up as disposing a division plate in a water washing tank, thereby a temperature controller and carbon fiber precursor are divided. Therefore, temperature of washing water can be accurately controlled. Moreover, spray nozzles in the water washing tank are controlled to improve washing performance of the carbon fiber precursor.

Description

Water washing device for carbon fiber strands

The new model relates to a water washing device for carbon fiber precursors, in particular to a water washing device for carbon fiber precursors including nozzles.

Carbon fiber is a high-strength fiber material, among which polyacrylonitrile (PAN)-based carbon fiber has the largest market share. Polyacrylonitrile-based carbon fibers are made from polyacrylonitrile precursor fibers. The production of polyacrylonitrile precursor fibers includes processes such as polymerization, filtration, coagulation, water washing, drying and densification, and drawing. During the spinning process, the spinning dope enters into the condensing solution through the spinning nozzle during condensing. However, due to the concentration difference between the spinning dope and the condensing solution, the solvent in the spinning dope diffuses into the condensing solution. At the same time, the water in the condensate will penetrate into the fiber through the cortex of the primary fiber. After this double diffusion process, the spinning dope will solidify to form nascent fibers. Since the spun fiber still contains a certain concentration of solvent, it is necessary to introduce the spun fiber into the water washing device to carry out the solvent cleaning operation on the surface and inside of the fiber.

In the production process of polyacrylonitrile precursor fiber, water washing is an important step, and its main purpose is to reduce the residual solvent in the fiber. If the washing effect is not good and the residual solvent content is high, the fibers are likely to be fused with single fibers in the subsequent drying and densification process, which will lead to defects such as hairiness and broken filaments. In addition, there may be abnormal production such as melting and breaking in the later oxidation process, and when the carbon fiber composite material is made into the carbon fiber composite material in the subsequent processing, it will cause problems such as uneven resin impregnation, deterioration of the physical properties of the carbon fiber composite material, and poor appearance.

However, if the water consumption is increased in order to improve the washing effect, when the consumption of washing water is larger, the steam consumption and waste water discharge will also increase accordingly, which will greatly increase the production cost.

In view of this, there is an urgent need to provide a water washing device for carbon fiber precursors, so as to effectively improve the water washing effect of the fibers without consuming a large amount of washing water.

One aspect of the present invention is to provide a water washing device for carbon fiber strands, which separates the temperature control device and the carbon fiber strands by arranging a partition in the water washing tank, so that the temperature of the cleaning water can be precisely controlled, and the control Nozzle to enhance the cleaning effect of carbon fiber strands.

According to an aspect of the present invention, there is provided a water washing device for carbon fiber strands, which includes a plurality of water washing tanks. The washing tanks are arranged in series along the production direction of the carbon fiber strands. Each washing tank includes a tank body, a partition plate, a plurality of transmission rollers, a plurality of guide plates, at least one nozzle, a temperature control device, a perforated plate and a pump. The tank system is configured to accept cleaning water, and has a wire input end and a wire outlet end. The wire outlet has a water inlet and an overflow. The partitions are arranged to partition the tank into upper and lower portions. The aforementioned water inlet is arranged at the lower portion, and the aforementioned overflow port is arranged at the upper portion. The drive rollers are located in the top area of the upper part and are configured to move the carbon fiber strands. The wire guide is arranged on the upper part and between the transmission rollers. The carbon fiber strands move over the yarn guide. The nozzle is arranged on the upper part, and between the wire-in end and the wire-out end. The nozzles are configured to spray water toward the carbon fiber strands from below. The temperature control device is provided in the lower part, and is configured to control the temperature of the washing water. The perforated plate is arranged at the wire outlet end and is connected to the separator. A pump system connects the tank to each nozzle. The cleaning water system flows into the tank body from the water inlet, and flows through the temperature control device and the perforated plate to enter the upper part.

According to an embodiment of the present invention, each of the above-mentioned washing tanks further includes a thermometer disposed at the upper portion and close to the wire-feeding end.

According to an embodiment of the present invention, each washing tank includes 1 to 5 nozzles.

According to an embodiment of the present invention, the flow direction of the cleaning water in the upper part is opposite to the production direction of the carbon fiber strands.

According to an embodiment of the present invention, the cleaning water flows from the overflow port of one of the washing tanks into the water inlet of the other washing tank, and the wire input end of one of the washing tanks is connected in series with the other one. wire end.

According to an embodiment of the present invention, the distance between each of the above-mentioned nozzles and the carbon fiber strands is 2 cm to 5 cm.

According to an embodiment of the present invention, the water spray rate of the above-mentioned nozzle is 50 L/hr to 100 L/hr.

According to an embodiment of the present invention, the spraying pressure of the above-mentioned nozzle is 1 kg/cm ² to 2 kg/cm ² .

According to an embodiment of the present invention, the above-mentioned pump is connected to the upper part of the tank body.

Applying the water washing device for carbon fiber strands of this new type, the temperature control device and the carbon fiber strands are separated by setting a partition in the washing tank, so the temperature of the cleaning water can be precisely controlled, and the carbon fiber strands can be strengthened by controlling the nozzles. washing effect.

Continuing from the above, the present invention provides a water washing device for carbon fiber strands, which separates the temperature control device and the carbon fiber strands by disposing a partition in the water washing tank, so that the temperature of the cleaning water can be precisely controlled, and the Control the nozzles in the washing tank to enhance the washing effect of carbon fiber strands.

The water washing device for carbon fiber raw silk provided by the present invention includes a plurality of water washing tanks, which are arranged in series along the production direction of the carbon fiber raw silk. The cleaning water is added to the last washing tank through which the carbon fiber strands pass, and then flows through the washing tanks in sequence in the opposite direction of the production direction. In some embodiments, the water wash device includes 8 to 12 water wash tanks. In some embodiments, the positions of each washing tank are arranged in a gradient, in other words, the height of the first washing tank is the lowest, and then increases sequentially. Furthermore, along the moving direction of the carbon fiber strands, the temperature in the water washing tank gradually increased.

Please refer to FIG. 1 , which is a schematic diagram of a washing tank 100 according to some embodiments of the present invention. The washing tank 100 includes a tank body 110 for accommodating washing water. The tank body 110 has a wire input end 110a and a wire outlet end 110b. It should be understood that the carbon fiber precursor CF enters the water washing tank 100 from the input end 110a along the production direction A, and then leaves the water washing tank 100 from the output end 110b. The tank body 110 also has a water inlet pipe 116 and an overflow pipe 118 on the side of the wire entry end 110a. As described above, the cleaning water flowing out of the overflow pipe 118 of the washing tank 100 will flow into the tank through the water inlet of the previous washing tank, wherein the thread input end 110a of the washing tank 100 is connected in series with the thread outlet end 110b of the previous washing tank . Furthermore, the water inlet pipe 116 of the last washing tank can be used to replenish washing water.

The washing tank 100 also includes a partition 120 configured to divide the tank body 110 into an upper portion 112 and a lower portion 114 . Furthermore, the separator 120 is connected to the porous plate 170 on the side close to the wire outlet 110b. The perforated plate 170 is configured so that wash water can flow from the lower portion 114 to the upper portion 112 .

In some embodiments, the water inlet pipe 116 is provided in the lower part 114 , and the overflow pipe 118 is provided in the upper part 112 . The washing tank 100 is provided with a plurality of drive rollers 130 in the top area of the upper portion 112, and the drive rollers 130 are configured to guide the carbon fiber strands CF. The number of the drive rollers 130 may vary according to the size of the washing tank 100 . In some embodiments, 2 to 3 drive rollers 130 may be provided. As shown in FIG. 1 , the drive roller 130 may rotate counterclockwise, for example, to guide the carbon fiber strands CF to move toward the exit end 110b. It should be noted that the bottom position of the transmission roller 130 must be lower than the water level height B in the tank body 110 to ensure that the carbon fiber strands CF move under the water level. It is added that the carbon fiber filaments CF still come into contact with air when entering and leaving the water washing tank 100 .

The water washing tank 100 also includes a wire guide plate 140 arranged on the upper portion 112 , and is arranged between the transmission rollers 130 . When the carbon fiber precursor CF passes through the water washing tank 100, it may be twisted after being washed by the water spray. However, the twist is not conducive to the cleaning of the carbon fiber precursor CF, and may cause overlapping and winding between the tows of the carbon fiber precursor CF. Therefore, the yarn guide plate 140 is arranged below the carbon fiber strands CF to separate individual carbon fiber strands CF, thereby improving the stability of the carbon fiber strands CF during water washing and moving. In other words, the carbon fiber strands CF are moved above the yarn guide 140 . The number of the wire guides 140 can also be changed according to the size of the washing tank 100 . In some embodiments, 3 to 5 wire guides 140 may be provided. The wire guide plates 140 are all disposed below the water level of the tank body 110 to ensure that the carbon fiber strands CF move under the water level.

In order to enhance the cleaning effect, the washing tank 100 further includes at least one nozzle 150 disposed on the upper portion 112 , which is arranged between the wire input end 110 a and the wire outlet end 110 b. In some embodiments, the nozzles 150 are positioned between the wire guides 140 and/or between the drive rollers 130 and the wire guides 140 . The nozzle 150 is arranged to spray water toward the moving carbon fiber strands CF from below. In some embodiments, the wash tank 100 includes 1 to 5 nozzles 150 , however, the number of nozzles 150 may vary depending on the size of the wash tank 100 . In some embodiments, the distance of the nozzle 150 from the carbon fiber strands CF is 2 cm to 5 cm. Within this distance range, the nozzle 150 has a better cleaning effect on the carbon fiber strands CF, and will not damage the tow. In some embodiments, the water spray volume of the nozzle 150 is 50 L/hr to 100 L/hr, and the spray pressure is 1 kg/cm ² to 2 kg/cm ² . Controlling the water spraying amount and spraying pressure of the nozzle 150 also contributes to the cleaning effect of the carbon fiber filaments CF, and can avoid defects such as hairiness of the subsequently obtained carbon fibers due to too strong sprayed water column.

Generally speaking, when the washing temperature in the washing tank 100 is higher, the diffusion speed of the solvent and water is faster, and the cleaning effect is better. However, if the carbon fiber precursor CF is directly put into the high-temperature washing tank 100, the single fiber will rapidly form a skin-core structure, which is not conducive to the washing effect. Therefore, the water temperature of the washing device should be gradually increased from the temperature of the condensing tank in the previous step, usually between 20°C to 100°C, preferably 30°C to 98°C. Therefore, the water washing tank 100 of the present invention is provided with a temperature control device 160 located at the lower part 114, which is configured to control the temperature of the washing water. In some embodiments, the temperature control device 160 uses steam and chilled water to control the heating and cooling of the washing water, respectively. In some embodiments, the washing water enters the lower part 114 of the washing tank 100 from the water inlet pipe 116 , then passes through the temperature control device 160 to adjust the washing water to a desired temperature, and then flows into the upper part 112 through the perforated plate 170 , and flows through the overflow. The pipe 118 flows out of the tank body 110, so the flow direction of the cleaning water in the upper part 112 is opposite to the production direction A of the carbon fiber precursor CF.

The washing tank 100 further includes a pump 180 which connects the tank body 110 and each of the nozzles 150 through pipelines. The cleaning water is supplied from the upper part 112 of the tank body 110 to the pump 180, and then pumped to the nozzle 150 to be ejected, so as to clean the carbon fiber filaments CF. Since the cleaning water has already flowed through the temperature control device 160, the water sprayed by the nozzle 150 will not cause the problem of uneven cleaning temperature.

In some embodiments, the washing tank 100 can optionally include a thermometer 190 , which is disposed on the upper portion 112 of the tank body 110 . In this embodiment, the thermometer 190 is preferably located near the wire entry end 110a to monitor the temperature of the cleaning water flowing to the pump 180 .

The following uses several embodiments to illustrate the application of the present invention. However, it is not intended to limit the present invention. Those with ordinary knowledge in the technical field of the present invention can make various changes and modifications without departing from the spirit and scope of the present invention. retouch. Experimental example 1

The nascent fibers obtained after condensing are first introduced into four groups of traditional immersion washing tanks, and then introduced into two groups of the new type of washing device of the present invention. It includes 2 groups of spray cleaning units, wherein each group of spray cleaning units includes 2 nozzles, which are respectively arranged between the wire guides. The water flow of the nozzle was 100 L/hr, and the flushing pressure was 2 kg/cm ² . The distance between the nozzle and the nascent fibers was 3 cm. The cleaned carbon fiber strands were sampled to measure residual solvent, water washing efficiency and single fiber fusion. The results are shown in Table 1.

Next, the carbon fiber strands are drawn in a bath, oiled, dried and dense, and stretched with pressurized steam to obtain a single fiber fineness of 1 denier (d) and a single fiber number of 3000 (total denier number 3000 d) precursor fibers. The number of hairiness of the obtained precursor fibers was measured, and the evaluation results are shown in Table 1. It is added that the single fiber denier is defined as the weight in grams of fibers with a length of 9000 m.

Then, the above-mentioned precursor fibers were gradually heated from 240°C to 280°C in an air atmosphere, and the speed ratio of the front and rear pulling rollers was controlled to be 1.0, so as to maintain the fiber tension, the stabilization process was carried out. The fiber density after the stabilization process was 1.35 g/cm ³ . Next, the fibers were gradually heated from 300 °C to 800 °C in nitrogen, and the speed ratio of the front and rear traction rollers was controlled to be 0.9 to carry out low-temperature carbonization, and then the temperature was gradually increased from 900 °C to 1800 °C, and controlled Under the condition that the speed ratio of the traction roller is 0.95, high temperature carbonization is carried out. Then, the fiber is introduced into an acid solution for electrolytic surface treatment, and then washed with water, dried and sizing to obtain a finished carbon fiber product. The strength and elongation of carbon fiber finished products were measured, and the measurement results are shown in Table 1. Experimental Example 2 to Experimental Example 8

Experimental Example 2 to Experimental Example 8 use the same production equipment and method as in Experimental Example 1 to produce carbon fiber precursors and carbon fiber products. The difference is that the water flow rate of the nozzle in Experimental Example 2 is 50 L/hr, and the flushing pressure is 1 kg/ cm ² ; the distance between the nozzle of Experimental Example 3 and the spun fiber is 5 cm; each washing tank of Experimental Example 4 contains 3 sets of spray washing units; each of the water washing tanks of Experimental Example 5 contains 1 set of spray washing units; Experimental Example 6 Each washing tank contains 5 groups of spray washing units; the water flow rate of the nozzle in Experimental Example 7 is 250 L/hr, and the flushing pressure is 3.5 kg/cm ² ; the distance between the nozzle and the spun fiber in Experimental Example 8 is 0.5 cm. The obtained evaluation results are shown in Table 1. Experimental Example 9 and Example 10

In Experimental Example 9, the spun fibers obtained after coagulation were introduced into five groups of traditional immersion washing tanks; in Experimental Example 10, the spun fibers obtained after coagulation were introduced into eight groups of traditional immersion washing tanks. It should be understood that the traditional immersion washing tank does not have nozzles and baffles, so the spun fibers are not separated from the temperature control device. In other words, the temperature control device of the traditional immersion washing tank is tied to the same layer as the spun fibers, so the temperature of the washing water is less uniform. The obtained evaluation results are shown in Table 1. Evaluation method Residual solvent

Take 5g to 10g of the raw silk sample into a round-bottom flask, heat and reflux for extraction for 4 hours, then stand to cool, and then measure the residual solvent amount W1 in the sample with a gas chromatograph (SHIMADZU GC-2014-09). Next, dehydrate the extracted samples with a dehydrator for 2 minutes, bake at 105° C. for 1.5 hours, cool for 10 minutes, and then weigh and record the weight W2. Then the ratio of the residual solvent amount W1 to the dry weight of the sample W2 (W1/W2) multiplied by 100 is the residual solvent, and the results are shown in Table 1. washing efficiency

(1) About 10 g of the nascent fiber before entering the washing device was taken, placed in a rotary centrifuge, and dehydrated on the surface at a rotating speed of 3000 rpm. After centrifugation for 3 minutes, the fiber weight W1 was recorded, and the weight W1 included the fiber and the weight of the water contained in the fiber. Next, put this nascent fiber into an oven to dry at 105° C. for 2 hours, and after drying the water, record the fiber weight W2. Then, put this nascent fiber into a conical flask, add 100 ml of water, and use the above-mentioned gas chromatograph to measure the concentration of DMSO (solvent) in the conical flask, denoted as C _GC , which can be calculated from the following formula (1 ) to obtain the DMSO concentration (C _{k -in} ) in the fibers before entering the water washing device.

(1)

(2) 單纖融著 In addition, the carbon fiber raw fibers obtained after passing through the water washing device are subjected to the above steps to calculate the DMSO concentration (C _{k -out} ) in the fibers after passing through the water washing device. _{Then, the concentration (C w} ) of DMSO in the washing tank was measured by gas chromatograph, and the washing efficiency (η) could be calculated using the following formula (2). The results are shown in Table 1.

(2) Single fiber fusion

The washed carbon fiber strands were cut to about 3 mm with a single-edged blade, and then poured into a nonionic surfactant solution (0.1%), dispersed and stirred at 60 rpm for 1 minute, and then the solution containing the carbon fiber strands was dispersed. On the black filter paper, to observe whether there is fusion between the single fibers (that is, to stick together due to melting), and to evaluate its state on a scale of 1 to 5, where 1 represents almost no fusion phenomenon, Level 5 represents serious fusion phenomenon. Table 1 shows the evaluation results of single fiber fusion. Hairiness

The precursor fibers in the running after steam extension were visually observed, and the amount of hairiness generated by running 1000 m was counted, and its state was evaluated on a scale of 1 to 5. The evaluation criteria are: the number of hairiness ≤ 1 is grade 1; the number of hair feathers ≤ 2 is grade 2; the number of hair feathers ≤ 5 is grade 3; 60 is level 5. Table 1 shows the evaluation results of the amount of hairiness. Carbon fiber properties

The finished carbon fiber is tied to a metal frame, and the carbon fiber is infiltrated with resin from top to bottom. The soaked carbon fiber bundles were dried at 90°C for 60 minutes, and then hardened and dried at 150°C for 120 minutes to obtain carbon fiber test pieces. The strength and elongation were measured with a tensile testing machine (ZWICK ROELL Z005). The results are shown in Table 1.

Table 1

In order to ensure the quality of the fibers and the need for subsequent oxidation and carbonization, the residual solvent content after washing must be less than 200 ppm. It can be seen from the above Table 1 that Experimental Examples 1 to 4 all have excellent water washing effect and fiber evaluation, and the carbon fibers all have a strength greater than 5000 MPa and an elongation greater than 2%. Furthermore, Experimental Example 5 only uses one set of spray washing units, and obviously its water washing effect is not as good as that of Experimental Examples 1 to 4 using two sets of spray washing units; similarly, the evaluation of single fiber fusion and hairiness in Experimental Example 5 is also poor. . On the contrary, experimental example 6 uses 5 groups of spray washing units, and the washing effect is obviously improved, but the evaluation of hairiness is not good, which is due to excessive water spraying on the carbon fiber precursor, resulting in an increase in the number of hairiness, which in turn affects the physical properties of the obtained carbon fiber. Experimental example 7 increases the cleaning water flow rate and flushing pressure, while experimental example 8 narrows the distance between the nozzle and carbon fiber strands. The results of both are similar to experimental example 6. Too close or too strong a water column can blow off the strands or cause hairiness, which can negatively affect the resulting carbon fiber. Experimental example 9 and experimental example 10 do not use the new type of washing device provided by the present model, and its washing effect is obviously poor, and the evaluation of single fiber fusion and hairiness number is also not good, and then the strength and elongation of the obtained carbon fiber are also not good. .

According to the above experimental example, the new water washing device provided by this new model can indeed have an excellent water washing effect on the carbon fiber strands, and under the condition of properly adjusting the nozzle, the evaluation of the single fiber fusion and the number of hairiness can be better, and then the obtained Carbon fiber has better physical properties.

Although the present invention has been disclosed above with several embodiments, it is not intended to limit the present invention. Anyone with ordinary knowledge in the technical field to which the present invention pertains can make various modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of this new model should be determined by the scope of the appended patent application.

100: washing tank 110: tank body 110a: wire entry end 110b: wire outlet 112: Upper 114: Lower 116: Water inlet pipe 118: Overflow pipe 120: Clapboard 130: Transmission roller 140: wire guide 150: Nozzle 160: Temperature control device 170: perforated plate 180: Pump 190: Thermometer A: Production direction B: water level height CF: carbon fiber precursor

Aspects of the present disclosure will be better understood from the following detailed description read in conjunction with the accompanying drawings. It should be noted that, as is standard practice in the industry, many features are not drawn to scale. In fact, the dimensions of many features can be arbitrarily scaled for clarity of discussion. [FIG. 1] is a schematic diagram illustrating a washing tank according to some embodiments of the present invention.

100: washing tank

110: tank body

110a: wire entry end

110b: wire outlet

112: Upper

114: Lower

116: Water inlet pipe

118: Overflow pipe

120: Clapboard

130: Transmission roller

140: wire guide

150: Nozzle

160: Temperature control device

170: perforated plate

180: Pump

190: Thermometer

A: Production direction

B: water level height

CF: carbon fiber precursor

Claims (9)

A water washing device for carbon fiber precursors, comprising: A plurality of washing tanks, wherein the washing tanks are arranged in series along a production direction of the carbon fiber precursor, and each of the washing tanks includes: a tank body, configured to accommodate a cleaning water, having a wire input end and a wire outlet end, and the wire input end has a water inlet and an overflow outlet; a partition plate configured to divide the tank body into an upper portion and a lower portion, wherein the water inlet is provided in the lower portion, and the overflow port is provided in the upper portion; a plurality of transmission rollers, arranged in a top area of the upper part, wherein the transmission rollers are configured to move the carbon fiber precursor; A plurality of wire guides are arranged on the upper part and between the transmission rollers, wherein the carbon fiber strands move above the wire guides; at least one nozzle, disposed on the upper part, between the yarn input end and the yarn output end, wherein the at least one nozzle is configured to spray water toward the carbon fiber precursor from below; a temperature control device disposed at the lower portion, wherein the temperature control device is configured to control a temperature of the washing water; a perforated plate, disposed at the wire outlet end and connected to the separator; and a pump connecting the tank and each of the at least one nozzle, wherein the pump is configured to pump the cleaning water to each of the at least one nozzle; Wherein, the cleaning water system flows into the tank body from the water inlet, and flows through the temperature control device and the perforated plate to enter the upper part. The washing device of claim 1, wherein each of the washing tanks further comprises: A thermometer is arranged on the upper part and is close to the end of the wire. The washing apparatus of claim 1, wherein each of the washing tanks includes 1 to 5 nozzles. The water washing device of claim 1, wherein a flow direction of the washing water at the upper portion is opposite to the production direction of the carbon fiber precursor. The washing device of claim 1, wherein the washing water flows from the overflow port of one of the washing tanks into the water inlet of the other one of the washing tanks, and the thread entry end of the one The wire outlet end of the other is connected in series. The water washing device of claim 1, wherein a distance between each of the at least one nozzle and the carbon fiber strands is 2 cm to 5 cm. The water washing device according to claim 1, wherein a water spray rate of one of the at least one nozzle is 50 L/hr to 100 L/hr. The water washing device of claim 1, wherein the spraying pressure of one of the at least one nozzle is 1 kg/cm ² to 2 kg/cm ² . The water washing device of claim 1, wherein the pump is connected to the upper portion of the tank.

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