A device for irradiation modification of PAN carbon fibers under electron beam accelerator beam

Abstract

The utility model discloses a PAN carbon fibre irradiation modification electron beam accelerator beam lower device, including first groove type roll, yarn spreader, thickness adjusting roller and second groove type roll, and each roll axis is parallel and acts on the upper and lower surface of fibre bundle respectively. The surface of first, second groove type roll all is equipped with several positioning groove, and the groove body sets up around the roll axis and groove width matches the fibre bundle width, and thickness adjusting roller is driven by the drive part and does horizontal reciprocating motion. The device still contains fibre bundle thickness detection device, and the detection light path that its emission part and receiving part constitute corresponds to the fibre bundle width direction and is perpendicular to the feeding direction. The detection device electric connection controller, and the controller is electrically connected with the actuator of thickness adjusting roller drive part. The utility model can avoid the folding of PAN fibre during irradiation, guarantees the uniformity of irradiation effect, makes the internal and external preoxidation degree of fibre bundle in subsequent preoxidation stage consistent, ensures that irradiation modification is full and directional optimization, shortens preoxidation time and does not influence fibre performance simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of carbon fiber technology, specifically to a beam-down device for an electron beam accelerator modified by PAN carbon fiber irradiation. Background Technology

[0002] This invention belongs to the field of irradiation modification and relates to a beam-down device for an electron beam accelerator in the PAN fiber industry. This device aims to simultaneously meet the requirements of the PAN fiber transport process and ensure controllable accelerator-based modification effects.

[0003] The effective irradiation area of ​​an industrial accelerator is typically rectangular, and its irradiation effect is influenced by the longitudinal penetration distance of the material. However, PAN fibers may fold during transport, resulting in uneven fiber bundle cross-sectional thickness or localized thickening. When the fiber bundle cross-sectional thickness is inconsistent, the penetration distance changes, leading to uneven irradiation.

[0004] After PAN fiber bundles are treated with electron beam irradiation, a large number of free radicals are generated. These free radicals can initiate the following reactions: 1. Intermolecular chain complexation initiates cross-linking reactions; 2. It undergoes a cyclization reaction with cyano groups; 3. It undergoes an oxidation reaction upon contact with oxygen.

[0005] These reactions help improve the pre-oxidation efficiency of the fibers. Uneven irradiation results in inconsistent pre-oxidation levels within the PAN fibers, which in turn affects the uniformity of the final polymer structure and ultimately reduces the performance of the carbon fibers.

[0006] Furthermore, during the high-speed transport of PAN fibers, the friction between the fibers and the spreading rollers causes a sharp increase in temperature, which not only shortens the lifespan of the spreading rollers but may also damage the properties of the PAN fibers themselves. On the other hand, the overall thickness of the fiber bundle will also change after spreading, depending on the transport speed (e.g., ...). Figure 5 (As shown). Therefore, it is necessary to adjust the position of the spreading roller in real time according to the operating status. Utility Model Content

[0007] The purpose of this invention is to provide a beam-down device for an electron beam accelerator modified by irradiation of P AN carbon fiber.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A beam-down device for an electron beam accelerator for irradiating and modifying PAN carbon fiber includes a first grooved roller, a spreading roller, a thickness adjusting roller, and a second grooved roller arranged sequentially in the fiber bundle feeding direction during irradiation. The axes of each roller are parallel, and each roller acts on the upper or lower surface of the fiber bundle respectively. The first grooved roller and the second grooved roller each have several parallel and spaced positioning grooves on their surfaces; the positioning grooves are arranged around the axis of the rollers, and the width of the grooves corresponds to the width of the fiber bundles. The thickness adjustment roller is driven to move horizontally reciprocatingly. It also includes a fiber bundle thickness detection device, comprising a transmitter and a receiver, wherein the detection optical path formed by the transmitter and the receiver corresponds to the width direction of the fiber bundle and is perpendicular to the fiber bundle feeding direction; The fiber bundle thickness detection device is electrically connected to a controller, which is electrically connected to the actuator of the drive unit of the thickness adjustment roller.

[0009] In the above scheme, the width of the positioning groove corresponds to the width of the fiber bundle, and is used to position the fiber bundle to ensure that the fiber bundle feeding direction does not deviate.

[0010] In a further technical solution, the irradiation section of the electron beam accelerator is positioned directly above the fiber bundle between the spreading roller and the thickness adjusting roller.

[0011] In a further technical solution, when the fiber bundle is fed, the first grooved roller and the second grooved roller act on the lower surface of the fiber bundle; the spreading roller and the thickness adjusting roller act on the upper surface of the fiber bundle.

[0012] In a further technical solution, the yarn spreading roller and the thickness adjusting roller are cylindrical smooth rollers with low-friction treated surfaces or low-friction material surfaces. The low-friction treated surface includes a surface treated with nanoscale lubrication. The low-friction material surface includes a ceramic material surface.

[0013] The yarn spreading roller and the thickness adjusting roller are cylindrical and smooth to ensure proper yarn spreading and reduce errors during adjustment. The low-friction surface or low-friction material is used to reduce friction and minimize heat generation and friction-induced damage between the roller and fiber during high-speed irradiation.

[0014] The nanoscale lubrication treatment and the ceramic material are existing technologies that can be mastered by those skilled in the art. Since they are not the utility model points of this case, they will not be described in detail here.

[0015] In a further technical solution, the emitting part of the fiber bundle thickness detection device is a light wave emitting device (such as a laser emitter), and the receiving part is an image sensing receiving device (such as a high-speed industrial camera).

[0016] The terms "first," "second," etc., used in this article do not specifically refer to order or sequence, nor are they intended to limit this case; they are merely used to distinguish components or operations described using the same technical terms.

[0017] The terms "connection" or "positioning" as used in this article can refer to two or more components or devices making direct physical contact with each other, or making indirect physical contact with each other, or to two or more components or devices operating or moving with each other.

[0018] The terms “include,” “including,” and “have” used in this article are all open-ended, meaning they include but are not limited to.

[0019] Unless otherwise specified, the terms used herein generally have their ordinary meaning in the context of the art, the subject matter, and the specific context. Certain terms used to describe this case will be discussed below or elsewhere in this specification to provide additional guidance to those skilled in the art in describing the case.

[0020] The terms “front,” “back,” “up,” “down,” “left,” and “right” used in this article are directional terms. In this case, they are only used to describe the positional relationship between the structures and are not intended to limit the specific direction of the protection scheme or its actual implementation.

[0021] The working principle and advantages of this utility model are as follows: This utility model relates to an electron beam accelerator under-beam device and irradiation method for PAN carbon fiber irradiation modification, aiming to simultaneously meet the transport requirements of PAN fibers and the controllability of accelerator modification effects. This device solves the problem of uneven irradiation effects, avoids damage to PAN fibers and wear on the spreading roller, thereby ensuring the efficient application of electron irradiation technology in the production of polyacrylonitrile (PAN) carbon fibers.

[0022] Traditional electron beam unwinding devices typically consist of only a first grooved roller and a second grooved roller. Adding a separate thickness adjustment roller, which can move obliquely along the fiber bundle direction, introduces both lateral and longitudinal distance parameters, increasing the complexity and uncertainty of the adjustment. By introducing a fixed spreading roller, the thickness adjustment roller only needs to move horizontally. According to mechanical analysis, the tension in the fiber direction remains constant, and the longitudinal difference in fiber height between the second grooved roller and the spreading roller and thickness adjustment roller remains unchanged. At this point, the force on the fiber is only related to the magnitude of angle β, which in turn depends solely on the horizontal distance between the thickness adjustment roller and the second grooved roller. Therefore, by adjusting the horizontal distance between the thickness adjustment roller and the second grooved roller, the force on the fiber bundle during spreading can be controlled, thereby achieving dynamic adjustment of the fiber bundle thickness.

[0023] Taking 24k polyacrylonitrile fiber as an example, before the yarn spreading is introduced, the width of the fiber bundle is 5-8mm. After the yarn spreading is introduced, the width of the fiber bundle is greater than 10mm, and the fiber spacing is 8-10mm. The effective width of the irradiation section is 1.5m, and the number of fibers that can pass under the bundle is 70-90.

[0024] In summary, this invention ensures the uniformity of irradiation effects by avoiding the folding problem of PAN fibers during irradiation. Simultaneously, this design ensures consistent pre-oxidation levels throughout the PAN fiber bundles during the subsequent pre-oxidation stage, guaranteeing sufficient and targeted modification of the PAN fibers by the irradiation technology, reducing pre-oxidation time without affecting fiber properties. Attached Figure Description

[0025] Appendix Figure 1 This is a top view of the beam-lowering device according to an embodiment of the present invention; Appendix Figure 2 This is a side view of the beam-lowering device according to an embodiment of the present invention; Appendix Figure 3 This is a schematic diagram showing the fiber forming an angle β between the thickness adjustment roller and the second grooved roller in an embodiment of the present invention; Appendix Figure 4 This is a schematic diagram of the cross-section of the fiber bundle after it has been unfurled according to an embodiment of the present invention; Appendix Figure 5 This is a schematic diagram of the cross-section of a fiber bundle before it is unblown, using existing technology.

[0026] In the above figures: 1. Fiber bundle; 2. First grooved roller; 3. Spreading roller; 4. Irradiation section; 5. Thickness adjustment roller; 6. Second grooved roller; 7. Receiving section; 8. Emitting section. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments: Example: The present invention will be clearly described below with illustrations and detailed description. Any person skilled in the art who understands the examples of the present invention can make changes and modifications based on the technology taught in the present invention without departing from the spirit and scope of the present invention.

[0028] The terminology used herein is for the purpose of describing specific embodiments only and is not intended to limit the scope of this work. Singular forms such as “a,” “this,” “this,” “the,” and “the” as used herein also include plural forms.

[0029] See appendix Figure 1 , Figure 2As shown, a beam-down device for an electron beam accelerator for irradiating and modifying PAN carbon fiber includes a first grooved roller 2, a spreading roller 3, a thickness adjusting roller 5, and a second grooved roller 6 arranged sequentially in the feeding direction of the fiber bundle 1 during irradiation. The axes of each roller are parallel, and each roller acts on the upper or lower surface of the fiber bundle 1 respectively.

[0030] The first grooved roller 2 and the second grooved roller 6 are provided with several parallel and spaced positioning grooves on their surfaces; the positioning grooves are arranged around the axis of the rollers and the groove width corresponds to the width of the fiber bundle 1; they are used to position the fiber bundle and ensure that the fiber bundle feeding direction does not deviate.

[0031] The thickness adjustment roller 5 is driven to move horizontally back and forth.

[0032] It also includes a fiber bundle thickness detection device, comprising a transmitter 8 and a receiver 7, wherein the detection optical path formed by the transmitter and the receiver corresponds to the width direction of the fiber bundle and is perpendicular to the fiber bundle feeding direction.

[0033] The fiber bundle thickness detection device is electrically connected to a controller, which is electrically connected to the actuator of the drive unit of the thickness adjustment roller 5.

[0034] Preferably, the irradiation section 4 of the electron beam accelerator is positioned directly above the fiber bundle 1 between the spreading roller 3 and the thickness adjusting roller 5.

[0035] Preferably, when the fiber bundle 1 is fed, the first grooved roller 2 and the second grooved roller 6 act on the lower surface of the fiber bundle 1; the yarn spreading roller 3 and the thickness adjusting roller 5 act on the upper surface of the fiber bundle 1.

[0036] Preferably, the yarn spreading roller 3 and the thickness adjusting roller 5 are cylindrical smooth rollers with low-friction treated surfaces or low-friction material surfaces; the low-friction treated surfaces include those with nano-level lubrication treatment; the low-friction material surfaces include those with ceramic material surfaces. This design reduces friction, minimizing heat generation and friction-induced damage between the rollers and fibers during high-speed irradiation.

[0037] Preferably, the emitting part 8 of the fiber bundle thickness detection device is a light wave emitting device (such as a laser emitter), and the receiving part 7 is an image sensing receiving device (such as a high-speed industrial camera).

[0038] like Figure 3As shown, traditional electron beam unwinding devices typically only include a first grooved roller 2 and a second grooved roller 6. If a thickness adjustment roller 5 is added separately, this roller can move obliquely along the fiber bundle direction, but this introduces both lateral and longitudinal distance parameters, increasing the complexity and uncertainty of the adjustment. By introducing a fixed spreading roller 3, the thickness adjustment roller 5 only needs to move horizontally. According to mechanical analysis, the tension in the fiber direction remains constant, and the longitudinal difference between the fiber height at the second grooved roller 6 and the fiber height between the spreading roller 3 and the thickness adjustment roller 5 remains unchanged. At this point, the force on the fiber is only related to the magnitude of the β angle (less than 60°), which in turn depends solely on the horizontal distance between the thickness adjustment roller 5 and the second grooved roller 6. Therefore, by adjusting the horizontal distance between the thickness adjustment roller 5 and the second grooved roller 6, the force on the fiber bundle during spreading can be controlled, thereby achieving dynamic adjustment of the fiber bundle thickness. Figure 4 (Illustrative diagram of the fiber bundle width after yarn unfolding).

[0039] During irradiation, the fiber bundle 1 passes sequentially above the first grooved roller 2, below the yarn spreading roller 3, below the irradiation section 4 of the electron beam accelerator, below the thickness adjustment roller 5, and finally above the second grooved roller 6.

[0040] Meanwhile, the fiber bundle thickness detection device detects the thickness of the fiber bundle located between the spreading roller 3 and the irradiation section 4 in real time.

[0041] If the actual thickness of the fiber bundle is less than or equal to a preset value, the thickness adjustment roller 5 remains in place.

[0042] If the actual thickness of the fiber bundle is greater than the preset value, the thickness adjustment roller 5 is driven to move horizontally back and forth to adjust the fiber bundle thickness, change the yarn tension and width, until the fiber bundle thickness measured by the fiber bundle thickness detection device is less than or equal to the preset value.

[0043] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the scope of protection of this utility model.

Claims

1. A beam-down device for an electron beam accelerator modified with PAN carbon fiber irradiation, characterized in that: The first grooved roller (2), the yarn spreading roller (3), the thickness adjusting roller (5) and the second grooved roller (6) are arranged in sequence according to the feeding direction of the fiber bundle (1) during irradiation. The axes of each roller are parallel, and each roller acts on the upper or lower surface of the fiber bundle (1). The first grooved roller (2) and the second grooved roller (6) are provided with several parallel and spaced positioning grooves on their surfaces; the positioning grooves are arranged around the axis of the rollers, and the groove width corresponds to the width of the fiber bundle (1); The thickness adjustment roller (5) is driven to move horizontally reciprocatingly; It also includes a fiber bundle thickness detection device, including a transmitter (8) and a receiver (7), wherein the detection optical path formed by the transmitter (8) and the receiver (7) corresponds to the width direction of the fiber bundle and is perpendicular to the feeding direction of the fiber bundle (1); The fiber bundle thickness detection device is electrically connected to a controller, which is electrically connected to the actuator of the drive unit of the thickness adjustment roller (5).

2. The downbeam device for the PAN carbon fiber irradiation modified electron beam accelerator according to claim 1, characterized in that: The irradiation section (4) of the electron beam accelerator is positioned above the fiber bundle (1) between the spreading roller (3) and the thickness adjustment roller (5).

3. The downbeam device for the PAN carbon fiber irradiation modified electron beam accelerator according to claim 1, characterized in that: When the fiber bundle (1) is fed, the first grooved roller (2) and the second grooved roller (6) act on the lower surface of the fiber bundle (1); the yarn spreading roller (3) and the thickness adjusting roller (5) act on the upper surface of the fiber bundle (1).

4. The beam-down device for the PAN carbon fiber irradiation-modified electron beam accelerator according to claim 1, characterized in that: The yarn spreading roller (3) and the thickness adjusting roller (5) are cylindrical smooth rollers with low-friction treated surfaces or low-friction material surfaces. The low-friction treated surface includes a surface treated with nanoscale lubrication. The low-friction material surface includes a ceramic material surface.

5. The beam-down device for the PAN carbon fiber irradiation-modified electron beam accelerator according to claim 1, characterized in that: The transmitting part (8) of the fiber bundle thickness detection device is a light wave transmitting device, and the receiving part (7) is an image sensing receiving device.

Images