Oiling device for large-tow precursor

Abstract

The utility model relates to the field of continuous production of large-tow carbon fibers, and discloses an oiling device for large-tow precursors. The device comprises a first oiling groove and a second oiling groove, the first oiling groove is filled with an oiling agent, so that the large-tow precursor is immersed in the oiling agent of the first oiling groove for first oiling, the second oiling groove is provided with a spray head, and the large-tow precursor subjected to first oiling is sprayed out of the oiling agent at intervals through the spray head for second oiling. After the oiling device provided by the utility model is used for oiling the large-tow protofilament, the large-tow protofilament is laid, folded and boxed, and when the large-tow protofilament is unwound and led to an oxidation furnace, the oil content difference between the flat section protofilament and the folded and bent section protofilament unwound from the box is within 0.1%, the folded and bent section protofilament does not generate single fiber adhesion and is easy to separate, and the large-tow protofilament is not easy to deform. The broken filament amount of the carbon fibers is reduced, the strength of the carbon fibers is improved, and the carbon fibers are soft in hand feeling and not hard or brittle.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of large tow carbon fiber continuous production, and specifically relates to an oiling device for large tow precursor. BACKGROUND

[0002] CN219567104U discloses a large tow carbon fiber continuous production yarn releasing and splicing device, which comprises a receiving member, a supporting member and a rotating assembly. When the remaining amount of the yarn cylinder precursor on the yarn releasing device needs to be replaced, the yarn cylinder removed from the yarn releasing device is sleeved on the receiving member. The device can provide a temporary placement position for the yarn cylinder that needs to be replaced, so as to save time for replacing the yarn cylinder and splicing the yarn during the replacement process, and shorten the production time for stopping oxidation and carbonization due to the replacement of the yarn cylinder. However, the large tow precursor can only be intermittently subjected to pre-oxidation and carbonization production due to the need to replace the yarn cylinder, and continuous production of the large tow carbon fiber cannot be realized.

[0003] CN108239801B discloses a large tow pitch-based carbon fiber and a preparation method thereof. After the pitch-based precursor is wound and collected, constant-tension yarn releasing and air twisting are performed, and the twisted synthetic precursor is sequentially subjected to hot roller drying, infusibilization, carbonization, graphitization, untwisting, sizing and drying, and finally wound and collected to prepare the large tow pitch-based carbon fiber. The method adopts plying and twisting to synthesize the large tow precursor. However, the large tow precursor is wound and collected, and the cylindrical large tow precursor cannot be continuously produced during the oxidation and carbonization process. After the cylindrical spool is unwound, the large tow precursor needs to be rewound, and the rewound large tow precursor is used as raw material for oxidation and carbonization to produce the large tow carbon fiber. Therefore, the method can only realize intermittent production of the large tow carbon fiber, and continuous production of the large tow carbon fiber product cannot be realized, which cannot guarantee the stability of the large tow carbon fiber product. SUMMARY

[0004] The utility model aims at overcoming the problem that the existing technology cannot realize continuous production of the large tow carbon fiber product and guarantee the stability of the large tow carbon fiber product. The utility model provides an oiling device for large tow precursor. After the large tow precursor is oiled by the oiling device, the large tow precursor is folded and packed. When the large tow precursor is unwound and guided to the oxidation furnace, the oil content difference between the flat section and the folded section of the large tow precursor unwound from the box is within 0.1%, the single fiber of the folded section does not adhere, the large tow precursor is easy to separate, the amount of carbon fiber hair is reduced, the strength of the carbon fiber is improved, the carbon fiber is soft and flexible, and does not become hard and brittle.

[0005] To achieve the above-mentioned purpose, the utility model provides an oiling device for large tow precursor, which comprises a supporting frame, an oiling device and a folding device. Figure 1The utility model provides an oiling device for large tow precursor, which comprises: a first oiling tank 1 and a second oiling tank 2; the first oiling tank 1 is filled with oil agent, so that the large tow precursor is immersed in the oil agent in the first oiling tank 1 for first oiling; the second oiling tank 2 is provided with a spray head 16, and the large tow precursor after the first oiling is sprayed with oil agent by the spray head 16 for second oiling.

[0006] Compared with the prior art, the utility model has at least the following beneficial effects:

[0007] After the large tow precursor is subjected to the second oiling, the large tow precursor is folded back and forth for packing in a box, and the large tow precursor packed in the box is stacked layer by layer, so that under the action of gravity, the moisture in the flat section of the precursor carries the oil agent and diffuses to the folded section of the precursor. At the same time, the folded section of the precursor is partially bundled due to the folding back and forth of the large tow precursor packed in the box, and the capillary effect is formed between the single fibers, so that the moisture in the flat section of the precursor carries the oil agent and diffuses to the folded section of the precursor. When the precursor is unwound to an oxidation furnace, the difference between the oil content of the flat section and the folded section of the precursor unwound from the box is within 0.1%, the single fibers of the folded section of the precursor do not adhere to each other, the precursor is easy to separate, the breaking rate of the carbon fibers is reduced, the strength of the carbon fibers is improved, the carbon fibers have a soft and smooth hand feeling, are not hard and brittle, the production stability of the carbon fibers is improved, and the quality of the carbon fibers is improved. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a schematic structural view of an oiling device for a large tow precursor in a preferred embodiment of the utility model.

[0009] Figure 2 is a schematic view of spray head spraying in a preferred embodiment of the utility model.

[0010] Figure 3 is a top view of a spray head spraying surface in a preferred embodiment of the utility model.

[0011] BRIEF DESCRIPTION OF DRAWINGS

[0012] 1, first oiling tank; 2, second oiling tank; 3, metal roller one; 4, metal roller two; 5, metal roller three; 6, metal roller four; 7, compression roller; 8, metal roller five; 9, metal roller six; 10, circulating pump; 11, first feeding pump; 12, second feeding pump; 13, first blending tank; 14, second blending tank; 15, feeding tank; 16, spray head; 17, pulse controller; 18, electromagnetic valve. DETAILED DESCRIPTION

[0013] The endpoints of the ranges and any values disclosed herein are not limited to the precise values recited as the exact dimensions are not critical to the nature of the disclosure. Each integer value within the range is also contemplated. The upper and lower limits of these disclosed ranges can be independently combined with one another to make new ranges.

[0014] In the utility model, if not otherwise specified, the orientation words such as "upper, lower, left, right" generally refer to the upper, lower, left and right shown in the drawings; "inner, outer" refers to the inner and outer relative to the outline of each component.

[0015] In the utility model, the material of the metal roller and the oiling tank is SUS316L stainless steel, but the scope of the utility model is not limited thereto.

[0016] As shown in Figure 1 The utility model provides an oiling device for large tow precursor, which comprises: a first oiling tank 1 and a second oiling tank 2; the first oiling tank 1 is filled with oil agent, so that the large tow precursor is immersed in the oil agent in the first oiling tank 1 for first oiling; the second oiling tank 2 is provided with a spray head 16, and the large tow precursor after the first oiling is sprayed with oil agent by the spray head 16 for second oiling.

[0017] In the utility model, after the large tow precursor is subjected to two oilings, the large tow precursor is folded back and forth for packing, and the packed large tow precursor is stacked layer by layer, and under the action of gravity, the moisture in the flat section of the precursor carries the oil agent and diffuses to the folded and bent section of the precursor. At the same time, the folded and bent section of the precursor is partially bundled due to the back-and-forth folding of the packed large tow precursor, and capillary effect is formed between the single fibers, which also causes the moisture in the flat section of the precursor to carry the oil agent and diffuse to the folded and bent section of the precursor. When the precursor is unwound to the oxidation furnace, the oil content difference between the flat section and the folded and bent section of the precursor unwound from the box is within 0.1%, the single fibers of the folded and bent section of the precursor do not adhere to each other, the large tow precursor is easy to separate, the carbon fiber breakage rate is reduced, the carbon fiber strength is improved, the carbon fiber feels soft and supple, is not hard and brittle, the carbon fiber production stability is improved, and the carbon fiber quality is improved.

[0018] In the utility model, one head and one tail of the precursor are reserved in each box. After the head and the tail of the precursor in each box are subjected to pre-oxidation treatment, the tail of the large tow precursor in the front box and the head of the large tow precursor in the rear box are connected by a connector, so that continuous yarn leading of the adjacent packed large tow precursors can be realized. Since the packed large tow precursors are connected in series for on-line continuous yarn leading at the creel, continuous production of the large tow carbon fiber is realized.

[0019] According to one embodiment of the utility model, the inlet of the first oiling groove 1 is provided with a metal roller one 3, and the outlet is provided with a metal roller four 6 and a compression roller 7.

[0020] According to one embodiment of the utility model, the feeding end of the spray head 16 is communicated with a mixer for mixing compressed air and oil.

[0021] According to one preferred embodiment of the utility model, the distance between the spray head and the original wire is H, and 500mm≤H≤900mm.

[0022] According to one embodiment of the utility model, the spray head 16 is provided with a plurality of.

[0023] According to one embodiment of the utility model, the compression roller 7 is located directly above the metal roller four 6, the large-tow original wire is introduced into the oil in the first oiling groove 1 through the metal roller one 3 for impregnation, and then the large-tow original wire is passed between the metal roller four 6 and the compression roller 7 to drain the excess oil on the original wire, so as to control the oil content of the flat laying section and the folding bending section of the large-tow original wire to be the same.

[0024] According to one embodiment of the utility model, an electromagnetic valve 18 is arranged at the communication position of the mixer and the spray head 16, so that the spray head 16 can spray oil at intervals.

[0025] In the utility model, the opening holding time and opening interval time of the electromagnetic valve 18 are controlled by the pulse controller 17. The pulse controller 17 sends an opening signal to the electromagnetic valve 18, the electromagnetic valve 18 is opened by electricity, the compressed air drives the oil to be sprayed from the spray head 16, the pulse controller 17 sends a closing signal to the electromagnetic valve 18, and the spray head 16 stops spraying oil.

[0026] According to one preferred embodiment of the utility model, a plurality of spray heads 16 are symmetrically distributed with the advancing direction of the large-tow original wire as the central axis, as shown in Figure 2 At least two symmetrically distributed spray heads 16 are arranged for the single-tow original wire.

[0027] In the utility model, the N-tow original wire is introduced and discharged through the metal roller in parallel state and is oiled through the second oiling groove, the large-tow original wire is oiled through at least 2N symmetrically distributed spray heads for the single-tow original wire respectively and simultaneously, the single-tow original wire and the spray head in the overlapping state are not drawn in the drawing, but this does not affect the effect of the utility model, which can be understood by those skilled in the art.

[0028] In the utility model, the spray head spraying surface is as shown in Figure 3 This can be understood by those skilled in the art, but does not limit the scope of the utility model.

[0029] According to one embodiment of the utility model, a plurality of metal rollers for immersion are arranged in the first oiling groove 1.

[0030] According to one embodiment of the utility model, the first oiling groove 1 is provided with a circulating pipeline for circulating the oil agent in the first oiling groove 1.

[0031] According to one embodiment of the utility model, a first dispensing groove 13 is arranged outside the first oiling groove 1 for adding oil agent.

[0032] According to one embodiment of the utility model, the plurality of metal rollers for immersion are symmetrically distributed along the central vertical axis of the first oiling groove 1 and are below the oil agent liquid level in the first oiling groove 1.

[0033] According to one embodiment of the utility model, the circulating pipeline is provided with a circulating pump 10.

[0034] In the utility model, the purpose of the first oiling groove 1 is to make the oil content of the large tow raw filaments in the flat laying section and the folded bending section after the first oiling the same.

[0035] According to one embodiment of the utility model, a second dispensing groove 14 is arranged outside the second oiling groove 2, the second dispensing groove 14 is communicated with a feeding groove 15 through a first feeding pump 11, and the feeding groove 15 is used to provide the oil agent sprayed by a spray head 16.

[0036] According to one embodiment of the utility model, the oil agent dripping during the oiling process is collected in the second oiling groove 2, when the oil agent liquid level reaches half the height of the second oiling groove 2, a second feeding pump 12 is opened to transport the oil agent in the second oiling groove 2 to the second dispensing groove 14.

[0037] According to one embodiment of the utility model, the second oiling groove 2 is sequentially provided with a metal roller five 8 for guiding in the large tow raw filaments and a metal roller six 9 for guiding out the large tow raw filaments along the advancing direction of the large tow raw filaments.

[0038] According to one embodiment of the utility model, metal roller two 4 and metal roller three 5 are arranged below the oil agent liquid level in the first oiling groove 1 for immersing the large tow raw filaments.

[0039] According to one embodiment of the utility model, the roller lengths of the metal roller two 4 and the metal roller three 5 are L2 and L3 respectively, the roller length of the metal roller one 3 is L1, the roller length of the metal roller four 6 is L4, and the roller length of the compression roller 7 is L7; the roller lengths of the metal roller five 8 and the metal roller six 9 are L5 and L6 respectively; L1=L2=L3=L4=L5=L6=L7= (N+16) x W, wherein N is the number of single tow raw filaments contained in the large tow raw filaments, and W is the width of the single tow raw filaments.

[0040] According to one embodiment of the utility model, the diameters of the metal roller one 3, the metal roller two 4 and the metal roller three 5 are respectively Phi 1, Phi 2 and Phi 3, the diameter of the metal roller four 6 is Phi 4, the diameter of the metal roller five 8 is Phi 5, the diameter of the metal roller six 9 is Phi 6, the diameter of the compression roller 7 is Phi 7, and 0.20 m <= Phi 1 = Phi 2 = Phi 3 = Phi 4 = Phi 5 = Phi 6 <= 0.40 m, Phi 7 = 1.02 * Phi 1.

[0041] According to one embodiment of the utility model, the distance between the center points of the metal roller two 4 and the metal roller three 5 is L8, and 1.0 m <= L8 <= 1.6 m.

[0042] According to one embodiment of the utility model, the distance between the center points of the metal roller five 8 and the metal roller six 9 is L9, and 1.0 m <= L9 <= 1.6 m.

[0043] The utility model discloses a kind of oiling methods of large tow precursor, and the method comprises:

[0044] Large tow precursor is divided into alternate flat section and folding bending section along length direction, first oiling is carried out to large tow precursor, and the oil content of each section is controlled to be same;

[0045] Second oiling is carried out to the flat section of large tow precursor, and the oil content difference between the flat section and folding bending section of large tow precursor is within 0.1% when folding and packing large tow precursor is unwound after second oiling.

[0046] In the utility model, the oil content of flat section of large tow precursor is higher than that of folding bending section after two oiling is completed, and after folding and packing large tow precursor, precursor is accumulated layer by layer, under the action of gravity, water in flat section of precursor carries oil agent, and diffuses to folding bending section of precursor.Meanwhile, the part of folding bending section of precursor is caused by folding and packing large tow precursor to and fro, and capillary effect is formed between single fiber, so that water in flat section of precursor carries oil agent, and diffuses to folding bending section of precursor.In the process of unwinding wire to oxidation furnace, the oil content difference between the flat section and folding bending section of precursor unwound from box is within 0.1%, single fiber of folding bending section of precursor does not adhere, easy to separate, reduce carbon fiber breakage rate, improve carbon fiber strength, carbon fiber is soft, not hard and brittle, improve carbon fiber production stability, and improve carbon fiber quality.

[0047] According to one embodiment of the utility model, the second oiling step to the flat section of large tow precursor comprises: using spray head to carry out second oiling to the flat section of large tow precursor, the oil agent spraying time of spray head is T1 millisecond, spray head spraying interval time is T2, 600 ms <= T1 <= 3000 ms, 60 ms <= T2 <= 400 ms.

[0048] According to one preferred embodiment of the utility model, the oil is sprayed from the spray head by compressed air controlled by the electromagnetic valve. In the utility model, the spray interval time of the spray head is millisecond level, and the electromagnetic valve can be used to control more accurately.

[0049] According to one embodiment of the utility model, the oiling speed of the original wire is v, and 50m / min≤v≤100m / min.

[0050] According to one embodiment of the utility model, the length of each flat section is L a , and 1000mm≤L a ≤2500mm.

[0051] According to one embodiment of the utility model, the length of each folding and bending section is L b , and 70mm≤L b ≤300mm.

[0052] According to one embodiment of the utility model, the large-tow original wire is composed of N tow original wires, and 20≤N≤150.

[0053] According to one embodiment of the utility model, the width of the single-tow original wire is W, and 25mm≤W≤130mm.

[0054] According to one embodiment of the utility model, after the first oiling, the oil content of each section is controlled to be the same, that is, the oil content of the flat section U1% and the oil content of the folding and bending section U2% are the same, and 0.80≤U1=U2≤2.00.

[0055] According to one embodiment of the utility model, after the second oiling, when the large-tow original wire is folded and packed and unwound, the difference between the oil content of the flat section U3% and the oil content of the folding and bending section U4% is within 0.1%, 0.80≤U3≤3.00, and 0.80≤U4≤3.00.

[0056] According to one embodiment of the utility model, the oil agent sprayed by the single spray head covers a diameter d, and 0.9×W≤d≤0.95×W.

[0057] In the utility model, the opening and closing of the electromagnetic valve are controlled by the pulse controller, which is easily understood by those skilled in the art. According to one embodiment of the utility model, the electromagnetic valve opening time T1 and the electromagnetic valve opening interval time T2.

[0058] According to one preferred embodiment of the utility model, T1=(L a -d) / v, and T2=(L b +d) / v. The above embodiment can accurately control the second oiling of the flat section of the large-tow original wire.

[0059] The following will be described in detail by examples, the raw materials used in the following examples and comparative examples are all disclosed in the prior art if not particularly limited, for example, can be directly purchased or prepared according to the preparation method disclosed in the prior art.

[0060] Comparative Example 1

[0061] A manufacturing method of 48K carbon fiber, including a precursor and carbon fiber production.

[0062] A polyacrylonitrile dope is spun into a large tow precursor by a sodium thiocyanate wet spinning production method through the production processes of coagulation forming, cold drawing, washing, acid washing, heat drawing, oiling, drying, folding and boxing.

[0063] The coagulation forming process parameters are: spinneret hole diameter 0.057mm, spinneret hole number 48000; coagulation forming temperature-1.5℃, coagulation bath flow 8500L / hour, coagulation bath concentration 14%;

[0064] The cold drawing process parameters are: cold drawing draw ratio 2.3 times;

[0065] The washing process parameters are: washing temperature 58℃, washing flow 6500L / hour;

[0066] The acid washing process parameters are: acid washing circulation amount 5000L / hour, acid washing PH value 2.0-3.0;

[0067] The heat drawing process parameters are: heat drawing temperature 95℃, heat drawing draw ratio 5.8 times;

[0068] The oiling process parameters are: one oiling way is adopted, the equipment structure of the first oiling tank in the comparative example is the same as that in the example. The oil agent concentration in the first oiling tank is 3.5%.

[0069] The drying, folding and boxing process parameters are: drying temperature 130℃; after drying and densification by the drying machine, the folded and boxed large tow precursor is swung back and forth in the box by a folded and boxed large tow precursor head swinging mechanism, and is stacked layer by layer. When the folded and boxed large tow precursor is stacked to the highest height of the box, the tow surface is compressed in the vertical direction by a compression plate, and then the tow is manually cut, to obtain the large tow precursor. The oil content of the large tow precursor in the flat area is 1.05%, and the oil content of the large tow precursor in the folded and bent area is 2.35%. The folded and boxed large tow precursor is sent to a carbon fiber production device through a conveying line.

[0070] The large tow precursor is subjected to the production processes of precursor head and tail pre-oxidation and connection, oxidation, carbonization, electrolytic surface treatment, washing, sizing, drying and winding, to obtain a large tow carbon fiber.

[0071] The parameters of the pre-oxidation and jointing process of the thread head and tail: the thread head and tail of the adjacent two boxes of the raw silk are placed on the tension frame, the pre-oxidation of the thread head and tail is carried out by using a pre-oxidation furnace, the pre-oxidation is controlled in two stages, the first stage pre-oxidation temperature is 240 DEG C, the pre-oxidation time is 30 min, the second stage pre-oxidation temperature is 260 DEG C, the pre-oxidation time is 30 min. The pre-oxidized thread head and tail are jointed by using a jointer and then are transported to the yarn frame production process.

[0072] The parameters of the oxidation process: the raw silk in the box is unwound and guided in the yarn frame production process, the guided silk is sequentially threaded through five oxidation furnaces, a low-temperature carbonization furnace, a high-temperature carbonization furnace, a surface treatment tank, a water washing tank, a sizing tank, a drying machine and a carbon fiber winding take-up machine. The temperatures of the five oxidation furnaces are 230 DEG C, 241 DEG C, 252 DEG C, 260 DEG C and 270 DEG C respectively. The draft ratios between the temperature zones of the oxidation furnaces are 1.12, 1.05, 0.98, 0.97 and 0.99 respectively.

[0073] The parameters of the carbonization process: the six-zone temperatures of the low-temperature carbonization furnace are 460 DEG C, 510 DEG C, 580 DEG C, 650 DEG C, 750 DEG C and 700 DEG C respectively, and the low-carbon draft ratio is 1.12. The six-zone temperatures of the high-temperature carbonization furnace are 1000 DEG C, 1150 DEG C, 1280 DEG C, 1300 DEG C, 1380 DEG C and 1280 DEG C respectively, and the high-carbon draft ratio is 0.96.

[0074] The tow at the high-carbon outlet is sequentially subjected to electrolytic surface treatment, water washing, sizing and drying and is wound.

[0075] The parameters of the electrolytic surface treatment process: the 15% ammonium bicarbonate aqueous solution is used as the electrolyte, the current intensity is controlled to be 350 amperes during electrolysis, and the electrolysis time is 55 seconds.

[0076] The parameters of the water washing process: the water washing temperature is 58 DEG C, and the water washing flow is 7500 L / hour.

[0077] The parameters of the sizing and drying process: the unsized carbon fiber is impregnated with the commercially available KTM-3F epoxy emulsion sizing agent for sizing, and vertical hot air drying is carried out at a drying temperature of 115 DEG C.

[0078] The parameters of the winding process: the sized and dried carbon fiber is wound by using a carbon fiber winding machine under a tension of 2100-2350 cN to obtain a 48K large tow carbon fiber.

[0079] The utility model will be described in detail by examples as follows. In the following examples, each parameter is obtained by the following method.

[0080] Oil content: the oil content is tested according to the test method for oil content of chemical fibers in the national standard of the People's Republic of China GB / T6504-2017 and is calculated according to the following formula.

[0081] Q (%) = (m3-m1) / (m2+m3-m1) x 100%

[0082] In the formula: Q - oil content of the sample, %;

[0083] m3 - the mass of the distillation flask after extraction, in grams (g);

[0084] m1 - the mass of the distillation flask before extraction, in grams (g);

[0085] m2 - the mass of the fiber after extraction, in grams (g).

[0086] Tensile strength: Refer to the test method for tensile properties of carbon fiber multifilament in the People's Republic of China National Standard GB / T3362-2017. Calculate the tensile strength according to the following formula.

[0087] σ t = P / A f

[0088] σ t - tensile strength, in megapascals (MPa);

[0089] P - breaking load, in Newton (N);

[0090] A f - cross-sectional area of carbon fiber multifilament, in square millimeters (mm 2 )

[0091] Tensile strength dispersion coefficient: Calculate the dispersion coefficient according to the provisions of the People's Republic of China National Standard GB / T3362-2017 and GB / T1446.

[0092] Lint amount: Refer to the test method for measuring the amount of lint on carbon fiber tows in the People's Republic of China National Standard GB / T41956-2022. Calculate the amount of lint on carbon fiber tows according to the following formula:

[0093] Q = m1-m0

[0094] In the formula: Q - amount of lint on carbon fiber tows, in milligrams (mg);

[0095] m1 - the mass of the lint collection material and lint, in milligrams (mg);

[0096] m0 - the mass of the lint collection material, in milligrams (mg);

[0097] Yarn sticking: Refer to the test method for testing the number of fibers that stick together and are difficult to separate in the People's Republic of China National Standard GB / T14339-2008 Chemical Fiber Short Fiber Defect Test Method.

[0098] Example 1

[0099] The oiling device for improving the uniformity of oiling of box-packed large tow raw filaments is used for industrialized production of 120 strands of 48K carbon fibers, including raw filaments and carbon fiber production.

[0100] The polyacrylonitrile raw solution is spun into large tow raw filaments through coagulation forming, cold drawing, washing, pickling, hot drawing, first oiling, second oiling, drying, and folding and boxing production processes.

[0101] The process parameters of the raw filament production processes, including coagulation forming, cold drawing, washing, pickling, hot drawing, drying, and folding and boxing production processes, are the same as those of Comparative Example 1. The production control mode and process parameters of the oiling process are different from those of Comparative Example 1.

[0102] The process parameters of the carbon fiber production processes, including thread end and tail pre-oxidation and connection, oxidation, carbonization, electrolytic surface treatment, washing, sizing, drying, and winding production processes, are the same as those of Comparative Example 1.

[0103] In this embodiment, the metal rollers and the oiling tank are made of SUS316L stainless steel.

[0104] As shown in Figure 1 The production control mode and process parameters of the oiling process in the production of large tow raw filaments are as follows:

[0105] The metal roller one 3, the metal roller two 4, the metal roller three 5, and the metal roller four 6 are supported and installed on the steel frame of the first oiling tank by means of bearing with seat. The metal roller one 3 and the metal roller four 6 are installed at the inlet and outlet of the steel frame of the first oiling tank, respectively, and the metal roller two 4 and the metal roller three 5 are installed in the middle of the first oiling tank. The diameter of the metal roller one 3 is Φ1=0.265 meters, the length of the roller is L1=4.1 meters, the diameter of the metal roller two 4 is Φ2, the diameter of the metal roller three 5 is Φ3, the diameter of the metal roller four 6 is Φ4, and the diameter of the metal roller one 3 is Φ1, Φ1=Φ2=Φ3=Φ4=0.265 meters. The length of the roller of the metal roller two 4 is L2, the length of the roller of the metal roller three 5 is L3, the length of the roller of the metal roller four 6 is L4, and the length of the roller of the metal roller one 3 is L1, L1=L2=L3=L4=4.1 meters. The press roller 7 is installed directly above the metal roller four 6, the diameter of the press roller is Φ7=0.270 meters, and the length of the roller is L7=4.1 meters.

[0106] The metal roller five 8 and the metal roller six 9 are supported and installed on the steel frame of the second upper oil tank 2 by means of the bearing with seat, and are respectively installed at the inlet and outlet of the steel frame of the second upper oil tank 2. The diameter Φ5 of the metal roller five 8 and the diameter Φ6 of the metal roller six 9 are the same as the diameter Φ1 of the metal roller one 3, and Φ5 = Φ6 = Φ1 = 0.265 meters. The roller length L5 of the metal roller five 8 and the roller length L6 of the metal roller six 9 are the same as the roller length L1 of the metal roller one 3, and L5 = L6 = L1 = 4.1 meters. 2 × 120 nozzles 16 are installed at the middle position of the second upper oil tank 2, i.e. directly above and below the running path of each tows of raw filaments.

[0107] At room temperature, the oil agent with a concentration of 30% and pure water are added into the first dispensing tank 13 to be dispensed into the oil agent with a concentration of 3.5%. The valve at the bottom of the first dispensing tank 13 is opened, and the oil agent with a concentration of 3.5% is added to the first upper oil tank 1, and the circulating pump 10 is started. The large tows of raw filaments at the outlet of the hot drawing machine are driven into the first upper oil tank 1 by the metal roller one 3, and after being immersed and oiled by the metal roller two 4 and the metal roller three 5 in the first upper oil tank 1, they run to the outlet metal roller four 6 and the pressure roller 7, and the excess oil agent is drained, so that the oil content of the large tows of raw filaments in the flat laying area and the folding and bending area is the same.

[0108] At room temperature, the oil agent with a concentration of 30% and pure water are added into the second dispensing tank 14 to be dispensed into the oil agent with a concentration of 1.0%. The valves at the bottom of the second dispensing tank 14 and the feed tank 15 are opened, and the first feed pump 11 is started. The oil agent with a concentration of 1.0% in the second dispensing tank 14 is conveyed to the feed tank 15, and the oil agent with a concentration of 1.0% in the feed tank 15 is conveyed to the oil agent pipeline, which is connected to the rear of the nozzle 16. A mixer is connected to the compressed air pipeline and the oil agent pipeline at the rear of the nozzle 16, and an electromagnetic valve 18 is arranged in the compressed air pipeline. The pulse controller 17 sends an opening signal to the electromagnetic valve 18, and the electromagnetic valve 18 is opened when it is powered on. The compressed air drives the oil agent to be sprayed from the nozzle, and the opening holding time T1 of the valve on the pulse controller 17 is set to 849 milliseconds, and the opening interval time T2 is set to 76 milliseconds. The electromagnetic valve is opened once every interval time T2, and the opening holding time T1. The electromagnetic valve is repeatedly opened and closed once by turn, to control the oil agent to be sprayed from the nozzle 16.

[0109] The large tow precursor running out of the metal roller four 6 of the first oiling tank 1 is guided into the metal roller five 8 of the second oiling tank 2, and the metal roller six 9 guides the large tow out. The single large tow width W is 30 mm, the diameter d of the nozzle 16 is 27 mm, the nozzle sprays oil to the running large tow precursor, the spraying time is 849 ms, the stop spraying time is 76 ms, the nozzle sprays oil again for 849 ms, the stop spraying time is 76 ms, and the spraying of oil is repeated in turn, so that the oil is controlled to be sprayed only to the laying area and not to the folding and bending area, and the second oiling is completed. The oil dripping during the spraying is collected in the second oiling tank 2, and when the oil level reaches half of the height of the second oiling tank, the second feeding pump 12 is started to convey the oil in the second oiling tank 2 to the second distribution tank 14.

[0110] Examples 2-6

[0111] The oiling device for improving the oil content uniformity of the boxed large tow precursor is used for industrial production of large tow precursors and large tow carbon fibers with different K numbers. The diameters of the rollers in the utility model are shown in Table 1. The lengths of the rollers and the distances between the metal rollers in the utility model are shown in Table 2. The oiling process production control method in the production process of the large tow precursor is the same as that in Example 1, wherein the spinneret hole number and the oiling process parameters are different, the spinneret hole number, the nozzle size and the spraying oil control parameters are shown in Table 3. The oil content of the large tow precursor prepared after the implementation of the oiling device for improving the oil content uniformity of the boxed large tow precursor is shown in Table 4. The performance indexes of the prepared carbon fibers are shown in Table 5.

[0112] Table 1 Diameter of roller (unit: m)

[0113]

[0114] Table 2 Length of roller and distance between metal rollers (unit: m)

[0115]

[0116] Table 3 Spinneret hole number, nozzle size and spraying oil control parameters (unit: mm)

[0117]

[0118] Table 4 Oil content of large tow precursor (unit: %)

[0119]

[0120] Table 5 Performance indexes of carbon fibers (laying section a, folding and bending section b)

[0121]

[0122] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solution of the present application, including the combination of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as disclosed content of the present application, and all belong to the protection scope of the present application.

Claims

1. An oiling device for large-tow filaments, characterized in that The oiling device for large-tow precursor filament comprises a first oiling tank (1) and a second oiling tank (2); the first oiling tank (1) is filled with oiling agent, and the large-tow precursor filament is immersed in the oiling agent in the first oiling tank (1) to perform the first oiling; the second oiling tank (2) is provided with a spray head (16), and the oiling agent is sprayed on the large-tow precursor filament after the first oiling through the spray head (16) to perform the second oiling.

2. The oiling device for large-tow precursor filament according to claim 1, wherein, a metal roller one (3) is arranged at the inlet of the first oiling tank (1), and a metal roller four (6) and a pressure roller (7) are arranged at the outlet of the first oiling tank (1); and / or the feeding end of the spray head (16) is communicated with a mixer for mixing compressed air and oiling agent; and / or the height distance between the spray head (16) and the precursor filament is H, and 500mm≤H≤900mm; and / or the spray head (16) is provided with a plurality of spray heads.

3. The oiling device for large-tow precursor filament according to claim 2, wherein, the pressure roller (7) is located directly above the metal roller four (6), the large-tow precursor filament is guided into the first oiling tank (1) by the metal roller one (3) to be immersed in the oiling agent, and then the large-tow precursor filament is passed between the metal roller four (6) and the pressure roller (7) to drain the excess oiling agent on the precursor filament; and / or an electromagnetic valve (18) is arranged at the communication position between the mixer and the spray head (16) to enable the spray head (16) to spray the oiling agent intermittently; and / or a plurality of spray heads (16) are symmetrically distributed with the advancing direction of the large-tow precursor filament as the central axis, and at least two symmetrically distributed spray heads (16) are arranged for a single large-tow precursor filament.

4. The oiling device for large-tow precursor filament according to claim 1, wherein, a plurality of metal rollers for immersion are arranged in the first oiling tank (1); and / or the first oiling tank (1) is provided with a circulation pipeline to circulate the oiling agent in the first oiling tank (1); and / or a first dispensing tank (13) is arranged outside the first oiling tank (1) to add oiling agent.

5. The oiling device for large-tow precursor filament according to claim 4, wherein, the plurality of metal rollers for immersion are symmetrically distributed along the central vertical axis of the first oiling tank (1) and are located below the oiling agent liquid level in the first oiling tank (1); and / or the circulation pipeline is provided with a circulation pump (10).

6. The oiling device for large-tow precursor filament according to claim 1, wherein, a second dispensing tank (14) is arranged outside the second oiling tank (2), the second dispensing tank (14) is communicated with a feeding tank (15) through a first feeding pump (11), and the feeding tank (15) is used to provide the oiling agent sprayed by the spray head (16).

7. The oiling device for large-tow precursor filament according to claim 6, wherein, the oiling agent dripping and collected in the second oiling tank (2) during the oiling process is delivered to the second dispensing tank (14) through a second feeding pump (12).

8. The oiling device for large-tow precursor filament according to claim 1, wherein, ​ The second oiling tank (2) is provided with a metal roller five (8) for guiding the large tow precursor in the advancing direction of the large tow precursor and a metal roller six (9) for guiding the large tow precursor in sequence; and / or The first oiling tank (1) is provided with a metal roller two (4) and a metal roller three (5) below the oil level for impregnating the large tow precursor.

9. The large tow precursor oiling device according to claim 8, wherein, The length of the metal roller two (4) and the metal roller three (5) is L2 and L3 respectively, the length of the metal roller one (3) is L1, the length of the metal roller four (6) is L4, and the length of the compression roller (7) is L7; the length of the metal roller five (8) and the metal roller six (9) is L5 and L6 respectively; L1=L2=L3=L4=L5=L6=L7=(N+16)×W, wherein N is the number of single tow precursor strands contained in the large tow precursor, and W is the width of the single tow precursor strand; and / or The diameter of the metal roller one (3) is Φ1, the diameter of the metal roller two (4) and the metal roller three (5) is Φ2 and Φ3 respectively, the diameter of the metal roller four (6) is Φ4, the diameter of the metal roller five (8) is Φ5, the diameter of the metal roller six (9) is Φ6, the diameter of the compression roller (7) is Φ7, and 0.20m≤Φ1=Φ2=Φ3=Φ4=Φ5=Φ6≤0.40m, Φ7=1.02×Φ1.

10. The large tow precursor oiling device according to claim 8, wherein, The distance between the center points of the metal roller two (4) and the metal roller three (5) is L8, and 1.0m≤L8≤1.6m; and / or The distance between the center points of the metal roller five (8) and the metal roller six (9) is L9, and 1.0m≤L9≤1.6m.

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