CARBON FIBER MANUFACTURING APPARATUS

Abstract

A carbon fiber manufacturing apparatus includes a feeding module, a high-temperature carbonization module, a plasma surface treatment module, a sizing module, and a receiving module. A carbon fiber precursor fiber bundle released from the feeding module is sequentially processed at a predetermined speed to perform high-temperature carbonization, plasma surface treatment, sizing, and so on. The carbon fiber precursor fiber bundle is heated to form a carbon fiber, and then the surface of the carbon fiber is coated with a resin oiling agent. Particularly, through the plasma surface treatment module, the surface of the carbon fiber is roughened and provided with functional groups, which is beneficial to enhance the interface bonding of the resin oiling agent and the carbon fiber. The structure of the carbon fiber is more stable and reliable. The cost of the carbon fiber production equipment and the working time can be reduced effectively.

Claims

1. A carbon fiber manufacturing apparatus, comprising: a feeding module and a receiving module, the receiving module being disposed in the vicinity of the feeding module, the feeding module and the receiving module constituting a carbon fiber drag route; a high-temperature carbonization module, disposed at the carbon fiber drag route and located between the feeding module and the receiving module for heating the carbon fiber drag route; a plasma surface treatment module, disposed at the carbon fiber drag route and located between the high-temperature carbonization module and the receiving module for supplying a plasma gas flow to the carbon fiber drag route; and a sizing module, disposed at the carbon fiber drag route and located between the plasma surface treatment module and the receiving module.

2. The carbon fiber manufacturing apparatus as claimed in claim 1, wherein the high-temperature carbonization module has a chamber, a gas supply module, and a microwave generating module, the carbon fiber drag route passes through the chamber, the gas supply module is used to supply an inert gas, and the microwave generating module is used to supply a high-frequency microwave.

3. The carbon fiber manufacturing apparatus as claimed in claim 2, wherein the plasma surface treatment module is provided with at least one plasma generator.

4. The carbon fiber manufacturing apparatus as claimed in claim 2, wherein the plasma surface treatment module is provided with at least one plasma generator located at upper and lower positions of the carbon fiber drag route, respectively.

5. The carbon fiber manufacturing apparatus as claimed in claim 2, wherein the chamber is an elliptic chamber.

6. The carbon fiber manufacturing apparatus as claimed in claim 5, wherein the chamber is provided with at least one pair of microwave-sensitive materials.

7. The carbon fiber manufacturing apparatus as claimed in claim 2, wherein the chamber is a flat plate chamber.

8. The carbon fiber manufacturing apparatus as claimed in claim 7, wherein the chamber is provided with at least one pair of microwave-sensitive materials.

9. The carbon fiber manufacturing apparatus as claimed in claim 3, wherein the plasma generator is able to generate the plasma gas flow having a power in the range of 100-10000 Watts.

10. The carbon fiber manufacturing apparatus as claimed in claim 3, wherein the plasma generator is able to generate an atmospheric plasma gas flow having a power in a range of 100-10000 Watts.

11. The carbon fiber manufacturing apparatus as claimed in claim 3, wherein the plasma generator is able to generate a low-pressure plasma gas flow having a power in the range of 100-10000 Watts.

12. The carbon fiber manufacturing apparatus as claimed in claim 3, wherein the plasma generator is able to generate a microwave plasma gas flow having a power in the range of 100-10000 Watts.

13. The carbon fiber manufacturing apparatus as claimed in claim 3, wherein the plasma generator is able to generate a glow plasma gas flow having a power in the range of 100-10000 Watts.

14. The carbon fiber manufacturing apparatus as claimed in claim 1, wherein the sizing module is provided with at least one reservoir.

15. The carbon fiber manufacturing apparatus as claimed in claim 1, further comprising a drying module, the drying module being disposed at the carbon fiber drag route between the sizing module and the receiving module.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 is a structural schematic view of a carbon fiber manufacturing apparatus in accordance with a first embodiment of the present invention;

[0028] FIG. 2 is a structural schematic view of a high-temperature carbonization module in accordance with an embodiment of the present invention;

[0029] FIG. 3 is a sectional schematic view of a carbon fiber after finishing a plasma surface treatment through a plasma surface treatment module of the present invention;

[0030] FIG. 4 is a sectional schematic view of a carbon fiber after finishing a sizing process through a sizing module of the present invention;

[0031] FIG. 5 is a structural schematic view of a carbon fiber manufacturing apparatus in accordance with a second embodiment of the present invention;

[0032] FIG. 6 is a structural schematic view of a high-temperature carbonization module in accordance with another embodiment of the present invention;

[0033] FIG. 7a illustrates a SEM image of an object to be tested without plasma treatment; and

[0034] FIG. 7b illustrates a SEM image of an object to be tested with the plasma treatment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0035] Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings.

[0036] The present invention discloses a carbon fiber manufacturing apparatus which can greatly improve the sizing quality of carbon fibers and effectively reduce the cost of the carbon fiber production equipment and the working time. As shown in FIG. 1, the carbon fiber manufacturing apparatus of the present invention comprises a feeding module 10, a receiving module 20, a high-temperature carbonization module 30, a plasma surface treatment module 40, and a sizing module 50.

[0037] Referring to FIG. 1 to FIG. 4, the feeding module 10 is used to supply a carbon fiber precursor fiber bundle 70A to be processed into a carbon fiber 70B. In practice, the carbon fiber precursor fiber bundle 70A may be formed of rayon, poly vinyl alcohol, vinylidene chloride, polyacrylonitrile (PAN), pitch, and the like. The surface of the carbon fiber precursor fiber bundle 70A may have not been processed with a pre-oxidation treatment or have been processed with a pre-oxidation treatment in advance.

[0038] The receiving module 20 is disposed in the vicinity of the feeding module 10, and corresponds to the feeding module 10 to constitute a carbon fiber drag route. The receiving module 20 includes a yarn winding assembly 21 to receive the carbon fiber 70B. The yarn winding assembly 21 performs a drag action on the carbon fiber 70B to be received.

[0039] The high-temperature carbonization module 30 is disposed at the carbon fiber drag route between the feeding module 10 and the receiving module 20 for heating the carbon fiber precursor fiber bundle 70A, enabling the carbon fiber precursor fiber bundle 70A to become the carbon fiber 70B having a predetermined carbon content. In practice, as shown in FIG. 2, the high-temperature carbonization module 30 has a chamber 31 for the carbon fiber precursor fiber bundle 70A to pass therethrough. The chamber 31 is formed with at least one microwave field concentration area 311 therein, and is provided with a gas supply module 32 to supply an inert gas and a microwave generating module 33 to supply a high-frequency microwave. Under the protection of the inert gas atmosphere, the electric field of the high-frequency microwave produces a sensing current to heat up and produce a high temperature quickly with the carbon fiber precursor fiber bundle 70A passing through the microwave field concentration area 311, enabling the carbon fiber precursor fiber bundle 70A to form the carbon fiber 70B having a predetermined carbon content.

[0040] The plasma surface treatment module 40 is disposed at the carbon fiber drag route between the high-temperature carbonization module 30 and the receiving module 20 to provide a plasma gas flow with a predetermined power to act on the carbon fiber 70B, such that the surface of the carbon fiber 70B is formed with a plasma-modified configuration 71 (shown in FIG. 3) which is rougher or has more functional groups relative to the carbon fiber precursor fiber bundle 70A.

[0041] The sizing module 50 is disposed at the carbon fiber drag route between the plasma surface treatment module 40 and the receiving module 20 for the plasma-modified configuration 71 on the surface of the carbon fiber 70B to be coated with a resin oiling agent 80 (as shown in FIG. 4). The sizing module 50 is provided with at least one reservoir 51 for storing the resin oiling agent 80. The resin oiling agent 80 may be a thermosetting resin oiling agent or a thermoplastic resin oiling agent.

[0042] Thereby, the carbon fiber manufacturing apparatus of the present invention can be operated in the integrated operation of the feeding module 10, the high-temperature carbonization module 30, the plasma surface treatment module 40, the sizing module 50, and the receiving module 20. The carbon fiber precursor fiber bundle 70A released from the feeding module 10 is sequentially processed at a predetermined speed to perform the steps of high-temperature carbonization, plasma surface treatment, sizing, and so on, in a relatively more active and reliable manner. The carbon fiber precursor fiber bundle 70A is heated to form the carbon fiber 70B, and then the surface of the carbon fiber 70B is formed with the resin oiling agent 80.

[0043] The plasma surface treatment module 40 is provided with at least one plasma generator 41 for generating a plasma gas flow. In this embodiment, the plasma surface treatment module 40 is provided with at least one plasma generator 41 disposed at the upper and lower positions of the carbon fiber drag route respectively for generating a plasma gas flow to act on the surface of the carbon fiber 70B.

[0044] Since the plasma gas flow contains particles having energy, the impurities that originally adhere to the surface of the carbon fiber 70B can be broken to form small molecules by the impact of the plasma gas flow through the physical reaction (collision) of the plasma gas flow, and then the small molecules are blown away from the surface of the carbon fiber 70B by the air flow, so that the surface of the carbon fiber 70B is clean. In the subsequent procedure of the sizing module 50, the resin oiling agent 80 can be completely in contact with the carbon fiber 70B to increase the bonding effect. In addition, the impact of the plasma gas flow will also form the plasma-modified configuration 71 on the surface of the carbon fiber 70B. The plasma-modified configuration 71 is rougher relative to the carbon fiber precursor fiber bundle 70A, and is further formed with pores. The surface of the carbon fiber 70B is roughened or formed with the pores, which is beneficial to increase the contact area between the resin oiling agent 80 and the carbon fiber 70B in the subsequent procedure of the sizing module 50. The resin oiling agent 80 penetrates into the pores, and the resin oiling agent 80 is anchored between the pores to form an anchor effect to enhance the bonding effect of the resin oiling agent 80 and the carbon fiber 70B.

[0045] The plasma gas flow also makes the surface of the carbon fiber 70B generate a chemical reaction at the same time, so that at least one functional group (such as OH, N, etc.) is added to the surface of the carbon fiber 70B. In the procedure of the sizing module 50, the surface tension of the surface of the carbon fiber 70B is increased due to the presence of the functional group, which is beneficial to improve the wetting effect for the resin oiling agent to be coated on the carbon fiber 70B. That is, the contact angle of the resin oiling agent 80 to the carbon fiber 70B becomes small, so that the resin oiling agent 80 can be quickly or instantaneously coated on the carbon fiber 70B, and the speed of the procedure of the sizing module 50 is increased, thereby accelerating the overall production speed of the carbon fiber 70B. The presence of the functional group such as the OH group reacts with the resin oiling agent 80, such as epoxy resin (Epoxy), to generate hydrogen bonding, thereby increasing the bonding effect.

[0046] In practice, the plasma generator 41 is able to generate a plasma gas flow having a power in the range of 100-10000 Watts, or an atmospheric plasma gas flow having a power in a range of 100-10000 Watts, or a low-pressure plasma gas flow having a power in the range of 100-10000 Watts, or a microwave plasma gas flow having a power in the range of 100-10000 Watts, or a glow plasma gas flow having a power in the range of 100-10000 Watts.

[0047] The plasma surface treatment module of the present invention provides a dry-type surface treatment for the carbon fiber. This not only prevents the carbon fiber from generating additional impurities or sediment but also reduces the working time and working procedure of drying after the completion of the plasma surface treatment.

[0048] As shown in FIG. 5, the carbon fiber manufacturing apparatus of the present invention may further comprise a drying module 60. The drying module 60 is disposed at the carbon fiber drag route between the sizing module 50 and the receiving module 20 for the resin oiling agent 80 to be firmly adhered to the surface of the carbon fiber 70B. In practice, the drying module 60 is provided with at least one blast furnace 61 to generate hot blast.

[0049] The foregoing inert gas may be nitrogen, argon, helium, or a combination thereof. The frequency of the high-frequency microwave may be in the range of 300-30,000 MHz, and its microwave power density may be in the range of 1-1000 kW/m.sup.3.

[0050] In the embodiment as shown in FIG. 2, the chamber 31 may be an elliptic chamber, or the chamber 31 may be a flat plate chamber (as shown in FIG. 6). As shown in FIG. 6, whatever the chamber 31 is, the chamber 31 is provided with a pair of microwave-sensitive materials 34 therein, thereby enhancing the focusing effect on the microwave field in order to further accelerate the high-temperature carbonization process. In practice, the microwave-sensitive materials 34 may be one of graphite, carbide, magnetic compound, nitride, and ionic compound or a combination thereof.

[0051] Due to the resonant effect of microwave heating, the carbonization of the carbon fiber is enhanced rapidly and more crystalline carbons are formed and stacked, which leads to the formation of larger graphite crystalline molecules, namely, larger graphite crystalline thickness, while deriving a higher microwave induction heating effect is derived. Such a cycle generates an autocatalytic reaction, enabling the carbon fiber to be rapidly heated to the graphitization temperature (1500-3000 C.), and carbon atoms are reconstructed and rearranged more rapidly to form a graphite layer.

[0052] In other words, the same apparatus can be applied to a carbon fiber precursor fiber bundle whose surface has not been processed with a pre-oxidation treatment or a carbon fiber precursor fiber bundle whose surface has been processed with a pre-oxidation treatment in advance. It is only necessary to adjust the microwave power for the production, the apparatus can be used to produce general carbon fibers (1000-1500 C.) or high modulus carbon fibers (graphite fibers).

[0053] In a preferred embodiment, an article to be tested that the resin oiling agent 80 after the drying module 60 is firmly adhered to the surface of the carbon fiber 70B, and the treatment conditions of the plasma surface treatment module 40 are shown in Table 1 below:

TABLE-US-00001 TABLE 1 the conditions of the plasma surface treatment plasma gas consumption N.sub.2 200 L/min CDA 0.4 L/min plasma gas amount 200.4 L/min plasma power 0~1000 W plasma surface treatment time 0.025~0.100 sec. carbon fiber yarn width 7 mm yarn per unit time receiving 0.28 J/s capacity distance 1 mm

[0054] The ILSS strength (interlayer bonding force) was measured for an object to be tested in an environment of a temperature of 23 C. and a humidity of 50% RH by using an INSTRON measuring machine according to ASTM 2344, and the results are shown in Table 2 below:

TABLE-US-00002 TABLE 2 the relationship between the plasma surface treatment power (W), the processing time (sec.) and the interlayer bonding force (MPa) (epoxy resin used as the resin oiling agent) of PAN carbon fiber 12K plasma power (W) of surface interlayer bonding force (ILSS)(MPa) treatment 0.025 sec. 0.075 sec. 0.100 sec. 0(untreated) 70 70 70 250 71 73 75 500 73 76 81 750 75 81 85 900 79 86 88 1000 83 89 91

[0055] As can be seen from Table 2, the carbon fiber without the plasma surface treatment, the interlayer bonding force of the object to be tested is only 70 MPa. With an increase of the plasma power, for example, the processing time is 0.075 seconds and the plasma power is increased from the untreated (0 W, without plasma power) to 10000 W, the interlayer bonding force is increased from 70 MPa to 89 MPa. That is, the interlayer bonding force is increased to 127%.

[0056] In the procedure of the sizing module 50, the epoxy resin is used as the resin oiling agent 80, and the carbon fiber is used as the carbon fiber 70B. FIG. 7A shows a SEM image of the object to be tested without the plasma treatment. FIG. 7B shows a SEM image of the object to be tested with the plasma treatment. As shown in FIG. 7A, the SEM image of the object to be tested without the plasma surface treatment illustrates a void H between the resin oiling agent 80 and the carbon fiber 70B because the surface of the carbon fiber 70B is smooth and doesn't have functional groups. The void H causes a decrease in the strength of the object to be tested. That is to say, the bonding force between the carbon fiber and the resin oiling agent is insufficient for protecting the fiber.

[0057] As shown in FIG. 7B, the SEM image of the object to be tested with the plasma surface treatment illustrates that there is no void between the resin oiling agent 80 and the carbon fiber 70B because the surface of the carbon fiber 70B is rough and has functional groups (such as OH, N, etc.). The resin oiling agent 80 and the carbon fiber 70B are bonded tightly, so that the strength of the object to be tested is enhanced. That is, the adhesion between the carbon fiber and the resin oiling agent is enhanced, so that the purpose of protecting the fiber can be achieved.

[0058] Specifically, through the carbon fiber manufacturing apparatus of the present invention, the carbon fiber precursor fiber bundle is heated to form the carbon fiber in a relatively more active and reliable means, and the surface of the carbon fiber has the resin oiling agent thereon. In particular, the surface of the carbon fiber can be roughened by the plasma surface treatment module, and the surface of the carbon fiber is provided with the functional groups. The sizing quality of the carbon fiber can be greatly improved. By the microwave focusing heating way of the high-temperature carbonization module, the same apparatus can be applied to a carbon fiber precursor fiber bundle whose surface has not been processed with a pre-oxidation treatment or a carbon fiber precursor fiber bundle whose surface has been processed with a pre-oxidation treatment in advance. By simply adjusting the microwave power, the apparatus can be used to produce general carbon fibers or high modulus carbon fibers (graphite fibers) so as reduce the cost of the carbon fiber production equipment and the working time effectively.

[0059] Although particular embodiments of the present invention have been described in detail for purposes of illustration, various modifications and enhancements may be made without departing from the spirit and scope of the present invention. Accordingly, the present invention is not to be limited except as by the appended claims.