Method for preparing propeller by using chopped carbon fiber reinforced resin and application

Abstract

The invention relates to the technical field of carbon fiber reinforced resin, in particular to a method for preparing a propeller from chopped carbon fiber reinforced resin and application. The invention provides a method for preparing a propeller by using chopped carbon fiber reinforced resin, which comprises the following steps: crushing a carbon fiber pre-impregnated belt into a carbon fiber chopped belt with the length of 20-40mm, and then carrying out hot press molding to obtain the propeller, wherein the thickness of the carbon fiber pre-impregnated belt ranges from 0.05 mm to 0.10 mm. The propeller is prepared from the chopped carbon fiber reinforced resin, so that the mechanical property of the product can be improved while the advantages of chopped fibers are reserved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon fiber reinforced resin, and in particular to a method and application of preparing a propeller by utilizing short-cut carbon fiber reinforced resin. Background Art

[0002] Traditional ship propeller blades are usually cast with metal materials such as nickel-aluminum bronze alloy. Lightweight propellers can significantly reduce the moment of inertia and achieve lightweight shafting. At the same time, lightweighting can achieve large-scale propellers, thereby improving propeller performance. The fatigue strength of the material used has a great influence on the reliability of the propeller. Because the propeller rotates at high speed, it also has high requirements for the vibration characteristics of the material. Because the propeller rotates at high speed and high load for a long time, it has high requirements for the design freedom of the propeller structure and the designability of the material itself.

[0003] At present, propellers are manufactured by using carbon fiber reinforced resin (CFRP), which can achieve the characteristics of lightweight, high strength, low vibration, fatigue resistance, etc. compared with traditional metal propellers. In the process of preparing propellers, continuous carbon fiber reinforced resin is used, but there is no research on discontinuous carbon fiber reinforced resin as a raw material for manufacturing propellers. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a method and application of preparing a propeller using short-cut carbon fiber reinforced resin. By adopting the method of the present invention, short-cut carbon fiber reinforced resin is used as the raw material for manufacturing the propeller. By using the same pre-impregnation tape as the continuous fiber product, the fluidity of the short-cut fibers is retained, thereby reducing the molding defects of the complex structure, and at the same time, the mechanical properties of the product are improved.

[0005] In a first aspect, the present invention provides, in an optional embodiment, a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: crushing a carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 20-40 mm, and then hot pressing to obtain a propeller; Wherein, the thickness of the carbon fiber pre-impregnation tape is 0.05-0.10 mm.

[0006] In the present invention, compared with the traditional continuous carbon fiber reinforced resin, there are strict requirements on the thickness of the carbon fiber prepreg tape, which must be between 0.05-0.10mm. The thickness of the traditional carbon fiber prepreg tape is about 0.15mm or more. If the prepreg tape is too thick, the internal fiber flow during molding will produce a large internal structure unevenness, thereby affecting the mechanical properties of the propeller. On the contrary, if the carbon fiber prepreg tape is too thin, it will lead to uneven fiber spreading and bring too high costs.

[0007] Preferably, the length of the carbon fiber chopped tape is 20-30 mm, the width of the carbon fiber chopped tape is 5-10 mm, and the aspect ratio of the carbon fiber chopped tape is greater than or equal to 2.

[0008] In the present invention, by controlling the length, width and aspect ratio of the carbon fiber chopped tape, a relative balance between molding efficiency and mechanical properties can be achieved. Since the chopped carbon fiber reinforced resin has no requirements for the continuity of the fiber, by using the remaining carbon fiber pre-impregnated tape, the carbon fiber material can be recycled and reused, greatly reducing the production cost. The use of chopped carbon fiber reinforced resin to prepare a propeller can achieve high-precision and complex design of the propeller blade geometry, increase the propeller load, and reduce the cavitation effect.

[0009] Furthermore, the carbon fiber pre-impregnation tape is composed of a matrix and carbon fibers; wherein the carbon fibers account for 50-70% of the weight of the carbon fiber pre-impregnation tape. The matrix is ​​selected from one of a thermosetting epoxy resin or a thermoplastic epoxy resin. When the matrix is ​​a thermosetting epoxy resin, the temperature of the hot pressing molding is 120-155°C, the pressure is 3-5MPa, and the time is 20-40 minutes. When the matrix is ​​a thermoplastic epoxy resin, the temperature of the hot pressing molding is 220-300°C, the pressure is 8-10MPa, and the time is 1-3 minutes.

[0010] In the present invention, the parameters of the hot pressing molding need to be determined according to the material of the carbon fiber prepreg tape matrix. The carbon fiber prepreg tape can be a brand new carbon fiber prepreg tape or a remaining carbon fiber prepreg tape from production.

[0011] Preferably, after the hot pressing step, a cooling treatment is also included.

[0012] In the present invention, the cooling treatment method includes but is not limited to air cooling, air cooling or liquid cooling, as long as the propeller can be cooled to room temperature. The crushing method includes but is not limited to shearing, cutting, etc., as long as the carbon fiber pre-impregnated tape can be crushed into 20-40mm carbon fiber chopped tapes.

[0013] Compared with the prior art, the present invention has one of the following beneficial effects: 1. The present invention uses short-cut carbon fiber reinforced resin to prepare a propeller, which can improve the mechanical properties of the product while retaining the advantages of short-cut fibers; 2. By hot pressing chopped carbon fiber reinforced resin, faster molding time and lower manufacturing cost can be achieved compared with continuous carbon fiber reinforced resin; 3. Using short-cut carbon fiber reinforced resin to prepare propellers can achieve high-precision and complex design of propeller blade geometry, increase propeller load, and reduce cavitation effect; 4. Since short-cut carbon fiber reinforced resin has no requirements for the continuity of the fiber, by using the remaining carbon fiber pre-impregnation tape in production, the carbon fiber material can be recycled and reused, greatly reducing the production cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0015] Figure 1 This is a schematic diagram of the process of preparing a propeller using chopped carbon fiber reinforced resin in Example 1-6. DETAILED DESCRIPTION

[0016] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0017] The following is a specific example to illustrate the solution of the present invention. Example 1

[0018] This embodiment provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a new carbon fiber pre-impregnation tape with a thickness of 0.10 mm, in which the weight of carbon fiber accounts for 60% and the matrix is ​​thermosetting epoxy resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 30 mm and a width of 10 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 140°C, a pressure of 4 MPa, and a time of 30 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Example 2

[0019] This embodiment provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select the remaining carbon fiber pre-impregnation tape with a thickness of 0.05 mm, the weight of carbon fiber in the carbon fiber pre-impregnation tape accounts for 50%, and the matrix is ​​thermosetting epoxy resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 30 mm and a width of 5 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 155°C, a pressure of 3 MPa, and a time of 40 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Example 3

[0020] This embodiment provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a new carbon fiber pre-impregnation tape with a thickness of 0.10 mm, in which the weight of carbon fiber accounts for 70% and the matrix is ​​thermosetting epoxy resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 20 mm and a width of 5 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 120°C, a pressure of 5 MPa, and a time of 20 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Example 4

[0021] This embodiment provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a carbon fiber pre-impregnation tape with a thickness of 0.10 mm, the weight of the carbon fiber in the carbon fiber pre-impregnation tape is 60%, and the matrix is ​​thermoplastic nylon 6 resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 30 mm and a width of 10 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 250°C, a pressure of 9 MPa, and a time of 2 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Example 5

[0022] This embodiment provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a new carbon fiber pre-impregnation tape with a thickness of 0.05 mm, in which the weight of carbon fiber accounts for 50% and the matrix is ​​thermoplastic nylon 6 resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 30 mm and a width of 5 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 220°C, a pressure of 8 MPa, and a time of 1 minute; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Example 6

[0023] This embodiment provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a carbon fiber pre-impregnation tape with a thickness of 0.05 mm, the weight of the carbon fiber in the carbon fiber pre-impregnation tape is 70%, and the matrix is ​​thermoplastic nylon 6 resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 20 mm and a width of 5 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 300°C, a pressure of 8 MPa, and a time of 3 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Comparative Example 1

[0024] This comparative example provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a new carbon fiber pre-impregnation tape with a thickness of 0.15 mm, in which the weight of carbon fiber accounts for 60% and the matrix is ​​thermosetting epoxy resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 30 mm and a width of 15 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 140°C, a pressure of 4 MPa, and a time of 30 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Comparative Example 2

[0025] This comparative example provides a method for preparing a propeller using chopped carbon fiber reinforced resin, comprising the following steps: Step 1: Select a new carbon fiber pre-impregnation tape with a thickness of 0.15 mm, in which the weight of carbon fiber accounts for 60% and the matrix is ​​thermoplastic polyetheretherketone resin; Step 2: Cut the new carbon fiber pre-impregnated tape into carbon fiber chopped tapes with a length of 50 mm and a width of 20 mm; Step 3: hot-press the carbon fiber chopped tape into the designed propeller shape at a temperature of 140°C, a pressure of 4 MPa, and a time of 30 minutes; Step 4: Cool the hot-pressed product to room temperature to obtain a propeller. Comparative Example 3

[0026] This comparative example provides a method for preparing a propeller using continuous carbon fiber reinforced resin, comprising the following steps: Step 1: Select a new carbon fiber pre-impregnation tape with a thickness of 0.15 mm, in which the weight of carbon fiber accounts for 60% and the matrix is ​​thermosetting epoxy resin; Step 3: Cut and hot-press the carbon fiber prepreg tape according to the designed propeller shape. The hot-pressing temperature is 140°C, the pressure is 4MPa, and the time is 30 minutes. Step 4: Cool the hot-pressed product to room temperature to obtain a propeller.

[0027] Test example: performance tests were performed on the propellers prepared in Examples 1-6 and Comparative Examples 1-3, and the test indicators included the mechanical properties and service life of the propellers.

[0028] Mechanical properties test method: tensile test (ASTM D3039 / D3039M) is performed using standard test pieces.

[0029] The results are shown in Table 1: Table 1 Mechanical properties of propellers of Examples 1-6 and Comparative Example 3 It can be seen from Table 1 that by using a thin layer of carbon fiber prepreg tape to prepare a short-cut carbon fiber reinforced resin propeller, the same or even better mechanical properties as the propeller prepared by traditional high-performance continuous fiber can be achieved on the basis of fully utilizing the carbon fiber raw materials, while shortening the preparation time of the propeller, providing a solution for realizing low-cost mass production of propellers.

Claims

1. A method for preparing a propeller using chopped carbon fiber reinforced resin, characterized in that: The following steps are involved: The carbon fiber pre-impregnated tape is crushed into carbon fiber chopped tapes with a length of 20-40 mm, and then hot-pressed to obtain a propeller; Wherein, the thickness of the carbon fiber pre-impregnation tape is 0.05-0.10 mm.

2. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 1, characterized in that: The length of the carbon fiber chopped tape is 20-30 mm.

3. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 1, characterized in that: The width of the carbon fiber chopped tape is 5-10 mm.

4. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 2 or 3, characterized in that: The aspect ratio of the carbon fiber chopped tape is greater than or equal to 2.

5. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 1, characterized in that: The carbon fiber pre-impregnation tape is composed of a matrix and carbon fibers; The carbon fiber accounts for 50-70% of the weight of the carbon fiber pre-impregnated tape.

6. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 5, characterized in that: The matrix is ​​selected from one of thermosetting epoxy resin and thermoplastic nylon 6 resin.

7. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 6, characterized in that: When the matrix is ​​a thermosetting epoxy resin, the temperature of the hot pressing molding is 120-155° C., the pressure is 3-5 MPa, and the time is 20-40 minutes.

8. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 6, characterized in that: When the matrix is ​​thermoplastic nylon 6 resin, the temperature of the hot pressing molding is 220-300° C., the pressure is 8-10 MPa, and the time is 1-3 minutes.

9. The method for preparing a propeller using chopped carbon fiber reinforced resin according to claim 1, characterized in that: After the hot pressing step, a cooling treatment is also included.

10. Use of the method for preparing a propeller by using chopped carbon fiber reinforced resin according to any one of claims 1 to 9 in preparing propeller blades for ships.

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