An apparatus for spreading a carbon fiber bundle using a thermoplastic resin

Abstract

The utility model discloses a kind of device for widening carbon fiber bundle using thermoplastic resin, it is related to carbon fiber bundle widening technical field, including silicone rubber one-way duckbill valve, impregnation tank, round bar and Hoffman water stop clamp.Symmetrical holes for placing round bar are equipped in the both sides of impregnation tank, and front end is sealingly connected with silicone rubber one-way duckbill valve through tubular interface, and duckbill valve front end flat area clamps Hoffman water stop clamp.The device uses the tension of round bar and thermoplastic resin solution to make carbon fiber bundle preliminary widening and combine resin, and realizes carbon fiber bundle widening and resin content control by adjusting water stop clamp clamping force, and 3K, 6K etc. can be expanded to 15~35mm to the specification carbon fiber bundle, fiber surface adheres 10-20wt% thermoplastic resin, realizes widening and toughening synergy of composite material, reduces equipment cost.

Description

Technical Field

[0001] This utility model relates to the technical field of carbon fiber bundle broadening, specifically a device for broadening carbon fiber bundles using thermoplastic resin. Background Technology

[0002] Carbon fiber possesses advantages such as high specific strength, high specific modulus, and resistance to chemical corrosion, and is often used as a reinforcing material in polymer-based composites, finding wide applications in aerospace, new energy vehicles, and sports and leisure industries. Unidirectional carbon fiber bundles consist of thousands of carbon fiber filaments. These filaments are unevenly distributed within the cross-section of the fiber bundle, and aggregation between filaments is prone to occur, affecting resin wetting uniformity. This results in resin-rich and resin-poor regions in carbon fiber reinforced polymer composites, significantly impacting composite performance. Widening the carbon fiber bundle reduces the crossing or aggregation of filaments within the bundle. Widened filaments are more easily wetted by resin, while simultaneously improving the uniformity of fiber dispersion in the composite, fully leveraging the strength advantages of carbon fiber, and enhancing the mechanical properties of the composite. Traditional carbon fiber widening processes require continuous extrusion and ultrasonic vibration of the carbon fiber bundle, resulting in high equipment costs. Using thermoplastic resins allows for a synergistic effect between carbon fiber bundle widening and composite toughening, improving the mechanical properties of the composite. Summary of the Invention

[0003] The purpose of this invention is to provide an apparatus for broadening carbon fiber bundles using thermoplastic resin, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution: An apparatus for broadening carbon fiber bundles using thermoplastic resin includes a silicone rubber one-way duckbill valve, an impregnation tank, a round bar, and a Hoffman stop clamp.

[0005] As a further aspect of this utility model: the silicone rubber one-way duckbill valve is made of silicone rubber with a Shore hardness of 30-50; the solution inlet of the silicone rubber one-way duckbill valve is circular, with an inner diameter larger than the width of the carbon fiber after lateral expansion; the solution outlet of the silicone rubber one-way duckbill valve is flat, with a width consistent with the inner diameter of the solution inlet; the flat area of ​​the silicone rubber one-way duckbill valve has a certain length for clamping and fixing the Hoffman stop clamp; the flat area of ​​the silicone rubber one-way duckbill valve has a certain thickness, providing a certain deformation capability when the Hoffman stop clamp clamps the flat area of ​​the silicone rubber one-way duckbill valve, allowing the carbon fiber bundle to be smoothly pulled after being impregnated with thermoplastic resin solution; the inner side of the flat area of ​​the silicone rubber one-way duckbill valve is smooth to prevent carbon fiber breakage during the widening process of the carbon fiber bundle; the flat area of ​​the silicone rubber one-way duckbill valve has a preset length and thickness.

[0006] As a further embodiment of this utility model: the solution outlet at the front end of the impregnation tank is provided with a tubular interface for connecting the circular solution inlet of the silicone rubber one-way duckbill valve, and the diameter of the interface is consistent with the inner diameter of the circular solution inlet of the silicone rubber one-way duckbill valve; the two ends of the impregnation tank are provided with symmetrical holes for inserting round rods, and the diameter of the holes is the same as the diameter of the round rods.

[0007] As a further embodiment of this utility model: the round rod can be made of polypropylene, stainless steel, or other materials; the length of the round rod is greater than the width of the impregnation tank; and the diameter of the round rod is the same as the diameter of the holes on both sides of the impregnation tank.

[0008] As a further embodiment of this utility model: the Hoffman water-stop clamp can be made of stainless steel, tin-plated copper, or other materials; the effective clamping area length of the Hoffman water-stop clamp should be greater than the width of the flat area of ​​the silicone rubber one-way duckbill valve.

[0009] As a further embodiment of this novel experimental design: the carbon fiber bundle widening device can be used for any type of carbon fiber bundle, and the bundle can be selected from any specification such as 3K, 6K, 12K, 24K, etc.; the carbon fiber bundle widening device can expand the width of the carbon fiber bundle to 15~35 mm.

[0010] As a further aspect of this utility model: after the carbon fiber bundle broadening device broadens the carbon fiber bundle, 10-20 wt% thermoplastic resin can be attached to the fiber surface.

[0011] As a further embodiment of this invention, the thermoplastic resin may be selected from polysulfone, polyethersulfone, polyphenylene sulfone, and polyvinylidene fluoride, etc.

[0012] As a further aspect of this utility model, the following steps are included: Step S1: Based on the width data of the carbon fiber bundle to be prepared, select or manufacture appropriate-sized silicone rubber one-way duckbill valves, impregnation tanks, round bars, and Hoffman water-stop clamps. Step S2: Tightly connect the circular solution inlet of the silicone rubber one-way duckbill valve to the tubular interface at the front end of the impregnation tank; Step S3: Insert the round rod into the hole on one side of the impregnation tank and out through the hole on the other side; As a further improvement of this utility model, the following steps are included: Step S1: Insert the carbon fiber bundle from below the round bar in the impregnation tank, pass through the impregnation tank and the silicone rubber one-way duckbill valve interface in sequence, and exit from the front outlet of the silicone rubber one-way duckbill valve. Step S2: Clamp the Hoffman stop clamp to the flat area at the front end of the one-way duckbill valve; Step S3: Pour the thermoplastic resin solution into the impregnation tank to immerse the carbon fiber bundles in the thermoplastic resin solution; Step S4: Adjust the clamping force of the Hoffman waterstop clamp to broaden the carbon fiber bundle and control the resin content. Step S5: Use a winding machine to uniformly pull and stretch the carbon fiber bundle, then shape it in a coagulation bath, dry it, and wind it up. As a further embodiment of this invention, the coagulation bath may be selected from deionized water, anhydrous ethanol, and a water / anhydrous ethanol mixture, etc.

[0013] As a further embodiment of this invention, the traction rate can be selected as 1-5 m / min.

[0014] The advantages of this invention are as follows: This invention uses a method of immersing carbon fiber bundles in a thermoplastic resin solution and clamping the flat area of ​​a silicone rubber one-way duckbill valve with Hoffman water-stop clamps to achieve the widening of the carbon fiber bundles; the clamping force of the Hoffman water-stop clamps on the flat area of ​​the silicone rubber one-way duckbill valve allows the carbon fiber bundles to expand in the width direction and control the thermoplastic resin content; the thermoplastic resin immersion in the carbon fiber bundles and coagulation bath can shape the carbon fiber bundles and play a toughening role in the composite material. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is the front view of the present invention; Figure 3 This is a top view of the present invention; Figure 4 This is a schematic diagram of the structure of the round bar in this utility model; In the diagram: 1-Silicone rubber one-way duckbill valve, 2-Immersion tank, 3-Round bar, 4-Hoffman stop clamp. Detailed Implementation

[0016] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0017] See Figures 1-3In this embodiment of the present invention, a device for widening carbon fiber bundles using thermoplastic resin includes a silicone rubber one-way duckbill valve 1, an impregnation tank 2, a round rod 3, and a Hoffman water-stop clamp 4. The impregnation tank 2 is used to contain a thermoplastic resin solution. Symmetrical holes for inserting the round rod 4 are provided at both ends of the impregnation tank 2. The diameter of the holes is the same as the diameter of the round rod. The round rod 4 is used to press the carbon fiber bundle into the thermoplastic resin solution, so that the carbon fiber bundle is initially widened and uniformly impregnated in the thermoplastic resin solution in the impregnation tank 2. The solution outlet at the front end of the impregnation tank 2 is provided with a tubular interface for connecting the circular solution inlet of the silicone rubber one-way duckbill valve 1. The diameter of the interface is the same as the diameter of the circular solution inlet of the silicone rubber one-way duckbill valve 1. The flat area of ​​the silicone rubber one-way duckbill valve 1 is provided with a Hoffman water-stop clamp 4. The clamping force of the Hoffman water-stop clamp 4 on the flat area of ​​the silicone rubber one-way duckbill valve 1 is adjustable. By adjusting the clamping force, the carbon fiber bundle is widened and the thermoplastic resin content is controlled.

[0018] The working principle of this utility model is as follows: Step S1: Based on the required width data of the expanded carbon fiber bundle, select a silicone rubber one-way duckbill valve. The diameter of its circular inlet and the width of its front flat area should be greater than the width of the expanded carbon fiber bundle. The front flat area should also have a certain length and thickness for clamping the Hoffman stop clamp. Select a Hoffman stop clamp with an effective clamping area length greater than the width of the front flat area of ​​the silicone rubber one-way duckbill valve. Fabricate an impregnation tank with an open top. The front solution outlet should have a tubular interface for connecting to the solution inlet of the silicone rubber one-way duckbill valve. The interface diameter should be the same as the solution inlet diameter of the silicone rubber one-way duckbill valve. Symmetrical holes for inserting round rods should be provided on both sides of the impregnation tank, with the hole diameter matching the rod diameter. Select round rods with the same diameter as the holes on both sides of the impregnation tank and a length greater than the width of the impregnation tank. Step S2: Tightly connect the circular solution inlet of the silicone rubber one-way duckbill valve to the tubular interface at the front end of the impregnation tank; Step S3: Insert the round rod into the hole on one side of the impregnation tank and out through the hole on the other side; Step S4: Insert the carbon fiber bundle from below the round bar in the impregnation tank, pass through the impregnation tank and the silicone rubber one-way duckbill valve interface in sequence, and exit from the flat area of ​​the silicone rubber one-way duckbill valve. Step S5: Clamp the Hoffman stop clamp onto the flat area of ​​the one-way duckbill valve; Step S6: Pour the thermoplastic resin solution into the impregnation tank to bond the carbon fibers with the thermoplastic resin, and use the solution tension and the pressure of the round rod to initially broaden the carbon fiber bundle. Step S7: Adjust the clamping force of the Hoffman stop clamp on the flat area of ​​the silicone rubber one-way duckbill valve, and use the clamping force to widen the carbon fiber bundle and scrape off excess resin to control the resin content. Step S8: Use a winding machine to uniformly pull and widen the carbon fiber bundle, then shape it in a deionized water coagulation bath, dry it, and wind it up.

[0019] Example 1: Broadening operation of 12K specification carbon fiber bundles 1. Equipment selection and preparation A one-way duckbill valve made of silicone rubber with a Shore hardness of 40 is selected: its circular solution inlet has an inner diameter of 30mm (greater than the target width of 25mm), a flat front area with a length of 80mm and a thickness of 10mm, and a smooth inner side; The Hoffman stop clamp is made of stainless steel and has an effective clamping area length of 40mm (30mm wider than the flat area of ​​the duckbill valve). The impregnation tank is made of polypropylene, with a 30mm diameter tubular interface at the front end (which is consistent with the inner diameter of the duckbill valve inlet), and 12mm diameter symmetrical holes on both sides. The round bar is a stainless steel bar with a diameter of 12mm and a length of 150mm (the width of the impregnation tank is 100mm, and the length of the round bar is greater than the width of the tank).

[0020] 2. Device Assembly Seal the circular inlet of the silicone rubber one-way duckbill valve to the tubular interface at the front end of the impregnation tank (no resin leakage at the interface). The stainless steel round bar is inserted into the hole on one side of the impregnation tank and passes through the hole on the other side. The round bar fits the hole with a clearance and can rotate freely.

[0021] 3. Carbon fiber bundle stretching process 12K carbon fiber bundles are selected and inserted from below the round rod in the impregnation tank, so that the fiber bundles are completely immersed in the polyethersulfone resin solution (concentration 12wt%). With the help of the pressure of the round rod (the contact length between the fiber bundle and the round rod is 50mm) and the surface tension of the solution, the bundles are initially widened to 15mm. After passing through the impregnation tank, the fiber bundle enters the silicone rubber one-way duckbill valve and exits from the flat area. The Hoffman water-stop clamp is clamped in the middle of the flat area of ​​the duckbill valve, and the clamping force is adjusted to compress the thickness of the flat area by 1 / 3 (at this time, the thickness of the clamping part is about 6.7mm). The fiber bundle was pulled through the winding machine at a traction rate of 3 m / min. The fiber bundle width at the exit was observed to reach 25 mm and there were no broken single filaments. At the same time, excess resin was scraped off. The drawn fiber bundles are placed in a 25°C deionized water coagulation bath for shaping, dried at 80°C, and then wound up. The final amount of polyethersulfone resin adhering to the fiber surface is 15wt%.

[0022] Example 2: Broadening operation of 24K carbon fiber bundles 1. Equipment selection and preparation The silicone rubber one-way duckbill valve is made of silicone rubber with a Shore hardness of 50. The inner diameter of the circular inlet is 40mm, and the width, length and thickness of the flat front area are 40mm and 100mm respectively. The Hoffman waterstop clamp is made of tin-plated copper and has an effective clamping area length of 50mm. The tubular interface of the impregnation tank has a diameter of 40mm, and the holes on both sides have a diameter of 15mm; the round bar is made of polypropylene, with a diameter of 15mm and a length of 180mm (the width of the impregnation tank is 120mm).

[0023] 2. Expand the process 24K carbon fiber bundles are pressed into a polyphenylene sulfone resin solution (concentration 15wt%) by round rods, and initially spread to 20mm; Adjust the clamping force of the Hoffman stop clamp to compress the thickness of the flat area of ​​the duckbill valve by 1 / 2 (from 12mm to 6mm), with a traction speed of 2m / min; After being set in an anhydrous ethanol coagulation bath (20℃) and dried at 100℃, the fiber bundle width reaches 35mm and the resin adhesion amount is 20wt%.

[0024] Example 3: Broadening operation of 3K specification carbon fiber bundles 1. Equipment Selection The silicone rubber one-way duckbill valve has a Shore hardness of 30, a circular inlet inner diameter of 25mm, and a flat area width of 25mm. The Hoffman waterstop clamp has an effective clamping length of 30mm, a round bar diameter of 10mm, and a glue-impregnation tank interface diameter of 25mm.

[0025] 2. Expand the process 3K fiber bundles are initially spread to 10 mm using round rods and then immersed in a polyvinylidene fluoride solution (concentration 10 wt%). The water-stop clamp compresses the thickness of the flat area by 1 / 4 (from 8mm to 6mm), with a traction rate of 5m / min; After being dried in a deionized water coagulation bath, the fiber bundle width is 15mm and the resin adhesion amount is 10wt%.

[0026] Note: In the above embodiments, by adjusting the hardness of the silicone rubber, the clamping force of the water-stop clamp, and the traction rate, different specifications of carbon fiber bundles from 3K to 24K can be adapted to achieve a stable expansion of 15 to 35 mm. The amount of resin adhesion is controlled at 10 to 20 wt%, and there is no fiber breakage, which verifies the effectiveness of this device.

[0027] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. It will be apparent to those skilled in the art that this utility model is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or basic characteristics of this utility model. Therefore, the embodiments should be considered exemplary and non-limiting in all respects. The scope of this utility model is defined by the appended claims rather than the foregoing description, and thus all variations falling within the meaning and scope of equivalents of the claims are intended to be included within this utility model. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A device for broadening carbon fiber bundles using thermoplastic resin, characterized in that, The device includes a silicone rubber one-way duckbill valve, an impregnation tank, a round bar, and a Hoffman stop clamp. The impregnation tank has symmetrical holes on both sides for placing the round bar, with the hole diameter matching the round bar diameter. The front end of the impregnation tank has a tubular interface that is sealed to the circular solution inlet of the silicone rubber one-way duckbill valve, with the interface diameter matching the inner diameter of the circular solution inlet. The front end of the silicone rubber one-way duckbill valve is a flat area that holds the Hoffman stop clamp.

2. The apparatus according to claim 1, characterized in that, The silicone rubber one-way duckbill valve has a Shore hardness of 30-50 degrees; the inner diameter of the circular solution inlet of the silicone rubber one-way duckbill valve is larger than the width of the carbon fiber bundle after lateral expansion; the solution outlet of the silicone rubber one-way duckbill valve is flat, and its width is consistent with the inner diameter of the circular solution inlet; the flat area of ​​the silicone rubber one-way duckbill valve has a preset length and thickness, and the inner side is smooth.

3. The apparatus according to claim 1, characterized in that, The length of the round bar is greater than the width of the impregnation tank, and the material is polypropylene or stainless steel.

4. The apparatus according to claim 1, characterized in that, The effective clamping area of ​​the Hoffman stop clamp is longer than the width of the flat area of ​​the silicone rubber one-way duckbill valve, and the material is stainless steel or tin-plated copper.

5. The apparatus according to claim 1, characterized in that, The device is suitable for carbon fiber tows of 3K, 6K, 12K or 24K specifications.

6. The apparatus according to claim 1, characterized in that, The device can expand the width of carbon fiber bundles to 15~35mm.

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