Continuous fiber surface coating system

Abstract

The utility model discloses a continuous fiber surface coating system which comprises a cleaning unit, a sensitizing unit, an activating unit, a coating unit and a fiber guiding unit, and the fiber guiding unit is used for transporting the fibers to be sequentially treated by the cleaning unit, the sensitizing unit, the activating unit and the coating unit. According to the continuous fiber surface coating system provided by the utility model, the continuous fiber enters the cleaning unit after passing through the fiber guide unit so as to increase the roughness of the fiber surface, then enters the sensitization unit and the activation unit, and finally enters the coating unit for coating treatment, so that the continuous coating can be realized under the condition that the fiber is kept in a continuous state through the cooperation of all the units; and the plating efficiency is high, the plating uniformity effect is good, and the thickness is controllable.

Description

Technical Field

[0001] This utility model relates to the field of fiber surface treatment technology, and in particular to a continuous fiber surface coating system that is low in cost, high in efficiency, and can meet the needs of large-size and multi-filament applications. Background Technology

[0002] With the continuous advancement of aerospace technology, advanced aerospace equipment places higher demands on the lightweight, high-temperature resistance, strength, and modulus properties of materials. High-specific-strength, high-specific-modulus fiber-reinforced aluminum matrix composites have become a superior choice. Silicon carbide fiber, as a typical high-performance ceramic fiber, exhibits good interfacial compatibility with aluminum. Furthermore, silicon carbide fiber possesses excellent high-temperature resistance and oxidation resistance, making its application in aluminum matrix composites effective in improving the material's strength, temperature resistance, corrosion resistance, and fracture toughness. However, due to the poor wettability of silicon carbide fiber with the aluminum alloy matrix, a coating treatment is required on the surface of the silicon carbide fiber when preparing silicon carbide fiber-reinforced aluminum matrix composites using the liquid-phase method. This coating improves the wettability between the fiber and the matrix, enhances the interfacial bonding strength, and inhibits harmful interfacial reactions, which is crucial for improving the overall performance of the composite material.

[0003] Silicon carbide fiber surface coating can be carried out through both physical and chemical methods. Common fiber coating methods include chemical plating, physical vapor deposition (PVD), chemical vapor deposition (CVD), and electroplating. Among them, chemical plating and electroplating are relatively convenient and simple, have low equipment requirements, and have good application prospects.

[0004] However, most existing technologies for preparing surface coatings of silicon carbide fibers can only prepare surface coatings for relatively short fibers in batches. For example, patent application number CN201710061198.8 requires cutting the fibers before electroplating with nickel. The cut fibers are difficult to weave, limiting the size of the fiber reinforcement. Patent application number CN201811608906.6 requires large-scale dedicated magnetron sputtering equipment, which is relatively expensive. There is a lack of corresponding devices and processes on the market that can meet the needs of preparing large-size, multi-tow fiber composite materials. Utility Model Content

[0005] This invention provides a continuous fiber surface coating system to solve the technical problems of fiber size limitation and high device cost in the prior art.

[0006] To solve the above-mentioned technical problems, the technical solution proposed by this utility model is as follows:

[0007] A continuous fiber surface coating system includes a cleaning unit, a sensitization unit, an activation unit, a coating unit, and a fiber guiding unit. The fiber guiding unit transports the fibers sequentially through the cleaning, sensitization, activation, and coating units. After passing through the fiber guiding unit, the continuous fibers enter the cleaning unit to increase the surface roughness, then enter the sensitization and activation units, and finally enter the coating unit for coating treatment. Through the cooperation of each unit, continuous coating can be achieved while the fibers remain continuous under normal temperature and pressure, resulting in high coating efficiency, good coating uniformity, and controllable thickness.

[0008] As a further preferred embodiment of the above technical solution, the fiber guiding unit includes a yarn feeding device installed before the cleaning unit and a guiding device installed in the cleaning unit, sensitization unit, activation unit and coating unit; the yarn feeding device includes a fiber yarn frame, a yarn collecting plate and a yarn dispensing device arranged sequentially along the fiber transport direction, the fibers placed on the fiber yarn frame are introduced to the yarn dispensing device through the yarn collecting plate, so that the continuous fiber bundle is unfolded and laid out in parallel before being sent into the cleaning unit.

[0009] As a further preferred embodiment of the above technical solution, the fiber yarn frame is composed of transverse keels and longitudinal keels. The longitudinal keels are arranged side by side, and the surfaces of the longitudinal keels are provided with slots at intervals for mounting the transverse keels. The transverse keels are provided with fiber spool supports at intervals for loading fiber spools. The fiber yarn frame can select multiple transverse keels connected in parallel according to the needs of different fiber bundles, and load multiple fiber spools, thereby controlling the bundle-gathering effect of the fiber bundles. This allows the system of this utility model to select different strands of fiber for filament coating as needed, and can meet the needs of surface coating of large-size, multi-bundle continuous fibers.

[0010] As a further preferred embodiment of the above technical solution, the gap of the fiber collecting plate is wider than the width of the fiber bundle, and its thickness is slightly greater than the thickness of the fiber bundle; rubber rollers are installed in front of and / or behind the fiber collecting plate. The rubber rollers in front of and behind the fiber collecting plate can prevent the fibers from twisting and damaging them.

[0011] As a further preferred embodiment of the above technical solution, the fiber guiding unit further includes a winding machine installed after the coating unit.

[0012] As a further preferred embodiment of the above technical solution, the cleaning unit includes a cleaning liquid tank and a water tank arranged in sequence, and a guide device is installed below the liquid level of both the cleaning liquid tank and the water tank.

[0013] As a further preferred embodiment of the above technical solution, the coating unit includes a chemical plating tank and an electroplating tank arranged sequentially; a conductive wheel with the negative terminal of an external power supply is installed above the liquid level in the electroplating tank, and a metal electrode plate with the positive terminal of an external power supply is also installed inside the electroplating tank. The coating unit can be selected for single-element coating and composite coating as needed.

[0014] As a further preferred embodiment of the above technical solution, the number of metal electrode plates is three, which are symmetrically installed on the inner surface of the front end, the middle section and the inner surface of the rear end of the electroplating tank; the number of conductive wheels is consistent with the number of metal electrode plates.

[0015] As a further preferred embodiment of the above technical solution, an ultrasonic generator is installed at the bottom of the sensitization tank, activation tank, and chemical bath. The ultrasonic generator is located at the bottom of the container directly below the long, continuous fiber section.

[0016] As a further preferred embodiment of the above technical solution, a washing tank is provided between the sensitization unit and the activation unit, and between the activation unit and the coating unit, for cleaning the sensitized and activated fibers. The washing tank is used to clean the sensitized and activated fibers, removing the sensitizing and activating solutions adsorbed on the fiber surface.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0018] This invention provides a system for coating continuous fiber surfaces, which can achieve automated coating of continuous fiber surfaces. The fiber remains in a continuous state throughout the process, enabling uniform traction. The coating solution is stirred by ultrasound and aeration to accelerate ion migration in the coating, resulting in uniform coating and controllable thickness of single or composite coatings. Attached Figure Description

[0019] The accompanying drawings, which form part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an undue limitation of the present invention. In the drawings:

[0020] Figure 1 This is a schematic diagram of the system for the continuous fiber surface coating of Example 1;

[0021] Figure 2 This is a schematic diagram of the wire collecting plate in Example 1;

[0022] Figure 3 This is a schematic diagram of the fiber yarn frame in Example 1.

[0023] Legend:

[0024] Figure 1 In the middle section: 1. Fiber yarn frame; 2. Guide roller; 3. Yarn collecting plate; 4. Yarn feeding device; 41. Tension roller; 42. Guide roller; 51. Cleaning tank; 52. Water tank; 53. Guide roller; 6. Sensitization tank; 7. Washing tank; 8. Activation tank; 9. Ultrasonic generating device; 10. Chemical plating tank; 11. Electroplating tank; 111. Metal electrode plate; 112. Vent; 113. Conductive roller; 12. Winding machine;

[0025] Figure 2 In the middle: 31. Base; 32. Wire collecting strip bracket; 33. Wire collecting strip;

[0026] Figure 3 In the middle: 11. Longitudinal keel; 12. Transverse keel; 13. Fiber filament tube support. Detailed Implementation

[0027] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, the present invention can be implemented in many different ways as defined and covered by the claims.

[0028] Example 1:

[0029] like Figure 1 As shown, the continuous fiber surface coating system of this embodiment includes:

[0030] Fiber guiding unit: includes a yarn feeding device, a guiding device (thread guide roller 53), and a winding machine 12 installed in front of the cleaning tank 51. The yarn feeding device is installed in front of the cleaning unit and includes a fiber yarn frame 1, a guide roller 2, a yarn collecting plate 3, and a yarn discharging device 4; for example Figure 3 As shown, the fiber yarn frame 1 is composed of transverse keels 12 and longitudinal keels 11. The longitudinal keels 11 are fixedly installed and arranged side by side, with slots spaced apart on them. The detachable transverse keels are installed in the slots. Fiber bobbin supports 13 are spaced apart on the transverse keels 12 for loading fiber bobbins. Multiple transverse keels 12 can be connected in parallel to load multiple fiber bobbins according to the needs of different fiber bundles. The fibers placed on the fiber yarn frame are guided by guide wheels 2 and then pass through the yarn collecting plate 3 (e.g., ...). Figure 2 As shown, the yarn collecting plate 3 consists of a base 31, a yarn collecting strip support 32, and a yarn collecting strip 33 fixed on the yarn collecting strip support 32. The yarn is introduced into the yarn dispensing device 4 (consisting of a tension roller 41 and a yarn guiding roller 42), so that the continuous fiber bundle is unfolded and laid out in parallel, and then stretched by the tension roller 41 before being sent into the cleaning unit.

[0031] Cleaning unit: includes a separate cleaning tank 51 and a water tank 52. The cleaning unit is equipped with 5 wire guide rollers 53. The cleaning tank 51 is filled with cleaning fluid, and the water tank 52 is filled with water. There is one wire guide roller 53 below the liquid surface in the cleaning tank 51 and below the water level in the water tank 52.

[0032] Sensitization unit: includes a sensitization tank 6 containing a sensitizing solution, 5 wire guide rollers 53 are provided in the sensitization tank 6, and 3 wire guide rollers 53 are provided below the sensitizing solution level, wherein the sensitizing solution is an acidic stannous chloride solution;

[0033] Activation unit: includes an activation tank 8 containing an activation solution, with 5 wire guide rollers 53 inside the activation tank 8 and 3 wire guide rollers 53 below the activation solution level; wherein the activation solution is a mixture of AgNO3 solution and ammonia water;

[0034] The plating unit includes a chemical plating tank 10 and an electroplating tank 11. The chemical plating tank 10 contains a chemical plating solution and has five wire guide rollers 53. Three wire guide rollers 53 are located below the chemical plating solution level. An ultrasonic generator 9 is also located at the bottom of the chemical plating tank 10. The ultrasonic waves in the ultrasonic generator 9 operate at dual frequencies, with a frequency range of 20 kHz. The working cycle of the ultrasonic generator 9 is 6 seconds, followed by a 3-second pause before starting the next cycle. The electroplating tank 11 contains an electroplating solution and has four wire guide rollers 53 located below the electroplating solution level. Three conductive rollers 113 connected to the negative terminal of a power supply are located above the electroplating solution. Three metal electrode plates 111 connected to the positive terminal of a power supply are also located in the electroplating tank 11 (located at the front, middle, and rear ends of the electroplating tank 11, respectively).

[0035] A water washing tank 7 is provided between the sensitization tank 6 and the activation tank 8, and between the activation tank 8 and the electroless plating tank 10. An ultrasonic generator 9 is also provided in the sensitization tank 6 and the activation tank 8. A vent 112 is provided at the bottom of the electroless plating tank 10 and the bottom of the electroplating tank 11.

[0036] The continuous fiber surface coating system of this embodiment deposits a copper layer on the surface of continuous silicon carbide fibers. The copper layer is uniform in thickness, continuous, and without damage or breaks. The silicon carbide fiber body remains undamaged, and the strength of the fiber bundle does not significantly decrease after the copper layer is deposited on the silicon carbide surface. The preform woven with continuous copper-plated fibers of this embodiment has a copper layer deposited inside the fiber bundle and at the fiber weaving overlaps, which can achieve a complete and uninterrupted interface layer between the fiber and the matrix in the composite material, providing complete interface protection for the fiber reinforcement.

[0037] The strength of the coated fibers was tested, and the results are shown in Table 1.

[0038] Table 1: Comparison of fiber bundle strength before and after copper plating in Example 1

[0039]

[0040] Comparative Example 1:

[0041] The only difference between the system in this comparative example and that in Example 1 is that the ultrasonic generator 9 is not installed in the sensitization tank 6, activation tank 8, and chemical plating tank 10 of this comparative example, and ultrasonic assistance is not performed in the corresponding process steps during actual use.

[0042] The silicon carbide fibers with nickel plating prepared in this comparative example exhibit a "black core" phenomenon, where some monofilaments within the bundle are neither covered by the electroless copper plating nor the nickel plating. The coating distribution uniformity is poor.

[0043] Comparative Example 2:

[0044] The only difference between this comparative example system and Example 1 is that a water washing tank 7 is not provided between the sensitization tank 6 and the activation tank 8 in this comparative example, and in actual use, after sensitization, the sample is directly placed into the activation tank 8 for activation without being washed with water.

[0045] The silicon carbide fiber with a nickel-plated surface prepared in this embodiment has a partially exposed fiber body, and the surface plating is severely peeled off, resulting in poor plating adhesion.

[0046] The silicon carbide fibers with a nickel-plated surface prepared in this comparative example exhibited high resistance to fiber movement, resulting in fiber splitting and breakage, which reduced the fiber's mechanical properties and hindered weaving. Partially exposed fibers and severe surface coating peeling also resulted in poor coating adhesion.

[0047] The above are merely preferred embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. The above are merely preferred embodiments of this utility model, and the protection scope of this utility model is not limited to the above embodiments. For those skilled in the art, improvements and variations obtained without departing from the technical concept of this utility model should also be considered within the protection scope of this utility model.

Claims

1. A continuous fiber surface coating system, characterized in that, It includes a cleaning unit, a sensitization unit, an activation unit, a coating unit, and a fiber guiding unit; the fiber guiding unit is used to transport the fibers through the cleaning unit, sensitization unit, activation unit, and coating unit in sequence; the fiber guiding unit includes a yarn feeding device installed in front of the cleaning unit and a guiding device installed in the cleaning unit, sensitization unit, activation unit, and coating unit; the yarn feeding device includes a fiber yarn frame (1), a yarn collecting plate (3), and a yarn dispensing device (4) arranged in sequence along the fiber transport direction. The fibers placed on the fiber yarn frame (1) are introduced into the yarn dispensing device (4) through the yarn collecting plate (3), so that the continuous fiber bundle is unfolded and laid out in parallel before being sent into the cleaning unit.

2. The continuous fiber surface coating system according to claim 1, characterized in that, The fiber yarn frame (1) is composed of a transverse keel and a longitudinal keel. The longitudinal keels are arranged side by side, and the surface of the longitudinal keels is provided with slots for installing the transverse keels at intervals. The transverse keels are provided with fiber spool supports for loading fiber spools.

3. The continuous fiber surface coating system according to claim 1, characterized in that, The gap of the fiber collecting plate (3) is wider than the width of the fiber bundle, and the thickness is slightly greater than the thickness of the fiber bundle; rubber rollers are installed in front of and / or behind the fiber collecting plate (3).

4. The continuous fiber surface coating system according to claim 1, characterized in that, The fiber guiding unit also includes a winding machine (12) installed after the coating unit.

5. The continuous fiber surface coating system according to any one of claims 1-4, characterized in that, The cleaning unit includes a cleaning tank (51) and a water tank (52) arranged in sequence, and a guide device is installed below the liquid level of both the cleaning tank (51) and the water tank (52).

6. The continuous fiber surface coating system according to any one of claims 1-4, characterized in that, The plating unit includes a chemical plating tank (10) and an electroplating tank (11) arranged in sequence; a conductive wheel (113) with the negative terminal of an external power supply is installed above the liquid level of the electroplating tank (11), and a metal electrode plate (111) with the positive terminal of an external power supply is also installed inside the electroplating tank (11).

7. The continuous fiber surface coating system according to claim 6, characterized in that, The number of metal electrode plates (111) is three, which are symmetrically installed on the inner surface of the front end, the middle section and the inner surface of the rear end of the electroplating tank (11); the number of conductive wheels (113) is consistent with the number of metal electrode plates (111).

8. The continuous fiber surface coating system according to claim 6, characterized in that, The sensitization unit, activation unit and chemical plating tank (10) are equipped with an ultrasonic generator (9) at the bottom.

9. The continuous fiber surface coating system according to any one of claims 1-4, characterized in that, A water washing tank (7) is provided between the sensitization unit and the activation unit, and between the activation unit and the coating unit, for cleaning the sensitized fiber and the activated fiber.

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