A method for manufacturing carbon fiber fabric thermoplastic prepreg

Abstract

The invention discloses a method for manufacturing carbon fiber fabric thermoplastic prepreg, belonging to the technical field of composite materials. The steps of the manufacturing method include: impregnating carbon fiber yarn in thermoplastic resin suspension through suspension impregnation process, and drying the impregnated carbon fiber yarn to a water content of 5-50wt.%; weaving fabric with the carbon fiber yarn having a water content of 5-50wt.% after impregnation; drying and hot pressing the obtained fabric after secondary gluing to obtain carbon fiber fabric thermoplastic prepreg. The invention solves the problem of poor fiber impregnation that is easy to occur in the production of carbon fiber fabric thermoplastic prepreg by traditional impregnation process through impregnation of carbon fiber yarn, and compensates for the loss of resin on the surface of yarn bundle during weaving through secondary gluing operation, and can also adjust the content of resin on the surface of fabric, so as to meet the needs of different molding processes.

Description

Technical Field

[0001] The invention belongs to the technical field of composite materials, and in particular relates to a method for manufacturing carbon fiber fabric thermoplastic prepreg. Background Art

[0002] Carbon fiber fabric thermoplastic prepreg is usually difficult to evenly disperse the resin into the fiber due to the fabric structure, which is prone to problems such as poor impregnation, affecting the quality of the later molded products. At present, the common impregnation processes include powder impregnation process, suspension impregnation process, and film impregnation process. Due to the high melt viscosity of thermoplastic resins, especially high-performance engineering plastic resins, it is difficult to achieve good impregnation of fabrics.

[0003] Therefore, in view of the above technical problems, it is necessary to provide a method for manufacturing carbon fiber fabric thermoplastic prepreg. Summary of the invention

[0004] The object of the present invention is to provide a method for manufacturing carbon fiber fabric thermoplastic prepreg.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] A method for manufacturing a carbon fiber fabric thermoplastic prepreg comprises the following steps:

[0007] The carbon fiber yarn is impregnated in a thermoplastic resin suspension through a suspension impregnation process, and the impregnated carbon fiber yarn is dried to a water content of 5 to 50 wt. %; the impregnated carbon fiber yarn with a water content of 5 to 50 wt. % is used to weave fabric; the obtained fabric is glued for a second time, dried, and heat-pressed to obtain a carbon fiber fabric thermoplastic prepreg.

[0008] Preferably, the thermoplastic resin suspension is a PAEK suspension with a concentration of 70 to 120 g / L.

[0009] Preferably, the drying temperature of the carbon fiber yarn after the first impregnation with the thermoplastic resin suspension is 70-300°C.

[0010] Preferably, the carbon fiber yarn with a moisture content of 5 to 50 wt.% is stored in an environment with a relative humidity of 50 to 100%.

[0011] Preferably, the secondary gluing includes one or more of powdering, suspension spraying and powder coating.

[0012] Preferably, the temperature procedure of the drying includes firstly performing high-temperature drying at 100-400°C, and then performing high-temperature immersion at 300-500°C.

[0013] Preferably, the temperature of the hot pressing and shaping is 310-350°C.

[0014] Preferably, the hot pressing forming further includes a winding step.

[0015] The beneficial technical effects of the present invention are as follows:

[0016] The method for manufacturing carbon fiber fabric thermoplastic prepreg provided by the present invention solves the problem of poor fiber impregnation that is easy to occur in the production of carbon fiber fabric thermoplastic prepreg by traditional impregnation process through impregnation of carbon fiber yarn, compensates for the loss of resin on the surface of yarn bundle during weaving process through secondary gluing operation, and can also adjust the content of resin on the surface of fabric, so as to meet the needs of different molding processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of preparing carbon fiber fabric thermoplastic prepreg according to Example 1 of the present invention.

[0018] Figure 2 Schematic diagram of the equipment for yarn impregnation in Example 1 of the present invention.

[0019] Figure 3 This is a schematic diagram of the equipment for secondary impregnation in Example 1 of the present invention. DETAILED DESCRIPTION

[0020] Now, various exemplary embodiments of the present invention are described in detail, and this detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and embodiments of the present invention. It should be understood that the terms described in the present invention are only for describing specific embodiments and are not used to limit the present invention.

[0021] In addition, for the numerical range in the present invention, it is understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. The intermediate value in any stated value or stated range, and each smaller range between any other stated value or intermediate value in the range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0022] Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the invention pertains. Although only preferred methods and materials are described herein, any methods and materials similar or equivalent to those described herein may also be used in the practice or testing of the present invention.

[0023] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0024] Example 1 Flow chart of preparing carbon fiber fabric thermoplastic prepreg Figure 1 .

[0025] Example 1

[0026] Preparation of carbon fiber fabric thermoplastic prepreg:

[0027] (1) Yarn impregnation (see the schematic diagram of the yarn impregnation equipment for details) Figure 2 , wherein 1 is a yarn rack, 2 is a high temperature furnace, 3 is a dipping tank, 4 is an oven, 5 is a traction machine, and 6 is a winder): 3K carbon fiber yarn is put from the yarn rack 1, passed through a 350°C high temperature furnace 2 to remove the surface sizing agent, immersed in a dipping tank 3 containing a PAEK suspension with a concentration of 120g / L, and then passed through a 300°C oven 4, the drying speed and time are controlled to ensure that the moisture content of the yarn is 45%, and the yarn is pulled to the winder 6 for winding through the traction machine 5 to form a spindle impregnated with PAEK resin; the spindle is placed on the yarn rack, and a humidity controller is provided on the yarn rack to ensure that the relative humidity of the environment of the yarn rack is 80%;

[0028] (2) Weaving: The fabric is woven on a loom, and the PAEK yarn with a diameter of 0.05 mm prepared by the above spindle is used to lock the edge of the fabric and fix the fibers on the surface of the fabric to prevent fiber slippage and deformation of the fabric surface, without undergoing a hot pressing and shaping operation;

[0029] (3) Secondary impregnation (see the schematic diagram of the secondary impregnation equipment for details) Figure 3 , wherein 7 is a creel, 8 is a gluing device, 9 is a high-temperature oven, 10 is a hot pressing roller, and 11 is a winder): the above-mentioned fabric is unwound from the creel 7, and is sprayed with a PAEK suspension with a concentration of 120g / L on the upper and lower surfaces of the gluing device 8, and the spraying amount is maintained at 0.06L / min to make up for the loss of resin on the surface of the yarn bundle during the weaving process. The fabric enters the high-temperature oven 9 for high-temperature drying at 300°C and high-temperature impregnation at 410°C, and is hot-pressed and shaped by three groups of hot pressing rollers 10 with temperatures of 340°C, 330°C, and 310°C respectively. After cooling, it is reeled up by the winder 11 to complete the manufacture of carbon fiber fabric thermoplastic prepreg.

[0030] Comparative Example 1

[0031] Preparation of traditional carbon fiber fabric thermoplastic prepreg:

[0032] The 3K carbon fiber yarn is woven into carbon fiber fabric, which is impregnated in a glue tank containing a PAEK suspension with a concentration of 120g / L, and then dried at 300°C and impregnated at 410°C. It is then hot-pressed and shaped by three sets of hot pressing rollers at temperatures of 340°C, 330°C, and 310°C, and then rolled up by a winder after cooling to complete the manufacture of carbon fiber fabric thermoplastic prepreg.

[0033] Comparative Example 2

[0034] Preparation of carbon fiber fabric thermoplastic prepreg:

[0035] (1) Yarn impregnation: 3K carbon fiber yarn is unloaded from the creel, passed through a 350°C high-temperature furnace to remove the surface sizing agent, and then immersed in a dipping tank containing a PAEK suspension with a concentration of 120 g / L. Then, it is passed through a 300°C oven, and the drying speed and time are controlled to ensure that the moisture content of the yarn is 45%. The yarn is then pulled to a winder for winding by a traction machine to form a spindle impregnated with PAEK resin; the spindle is placed on a creel, and a humidity controller is provided on the creel to ensure that the relative humidity of the environment of the creel is 80%;

[0036] (2) Weaving: The fabric is woven on a loom, and the PAEK thread with a diameter of 0.05 mm prepared by the above-mentioned spindle is used to lock the edge of the fabric and fix the fibers on the surface of the fabric to prevent fiber slippage and deformation of the fabric surface; then the fabric is placed in a high-temperature oven for high-temperature drying at 300°C and high-temperature impregnation at 410°C, and is hot-pressed and shaped by three sets of hot pressing rollers at temperatures of 340°C, 330°C, and 310°C, respectively. After cooling, the fabric is wound up by a winder to complete the manufacture of carbon fiber fabric thermoplastic prepreg.

[0037] After testing, the porosity of the carbon fiber fabric thermoplastic prepregs prepared in Example 1, Comparative Example 1 and Comparative Example 2 is shown in Table 1.

[0038] Table 1 Porosity of carbon fiber fabric thermoplastic prepreg prepared in each group

[0039] Example 1 Comparative Example 1 Comparative Example 2 Porosity 4％ 11％ 8％

[0040] It can be seen from the data in Table 1 that the porosity of the carbon fiber fabric thermoplastic prepreg prepared in Example 1 is significantly lower than that in Comparative Example 1, indicating that the carbon fiber fabric thermoplastic prepreg preparation process provided in Example 1 can solve the problem of poor impregnation in the traditional carbon fiber fabric thermoplastic prepreg preparation process; in addition, compared with the traditional process of preparing carbon fiber fabric thermoplastic prepreg by dipping carbon fiber fabric, the process of dipping in the yarn stage and then weaving and hot pressing molding in the present invention also helps to solve the problem of poor impregnation. The preparation process provided by the present invention can effectively improve the efficiency of subsequent product molding and processing and improve product quality.

[0041] The embodiments described above are only descriptions of the preferred modes of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.

Claims

1. A method for producing a carbon fiber fabric thermoplastic prepreg, characterized in that: The following steps are involved: The carbon fiber yarn is impregnated in a thermoplastic resin suspension through a suspension impregnation process, and the impregnated carbon fiber yarn is dried to a water content of 5 to 50 wt. %; the impregnated carbon fiber yarn with a water content of 5 to 50 wt. % is used to weave fabric; the obtained fabric is glued for a second time, dried, and heat-pressed to obtain a carbon fiber fabric thermoplastic prepreg.

2. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The thermoplastic resin suspension is a PAEK suspension with a concentration of 70 to 120 g / L.

3. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The drying temperature of the carbon fiber yarn after the first impregnation with the thermoplastic resin suspension is 70-300°C.

4. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The carbon fiber yarn with a moisture content of 5 to 50 wt.% is stored in an environment with a relative humidity of 50 to 100%.

5. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The secondary gluing includes one or more of powdering, suspension spraying and powder coating.

6. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The temperature procedure of the drying includes firstly performing high-temperature drying at 100-400°C and then performing high-temperature dipping at 300-500°C.

7. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The temperature of the hot pressing and shaping is 310-350°C.

8. The method for producing carbon fiber fabric thermoplastic prepreg according to claim 1, characterized in that: The method further comprises a winding step after the hot pressing forming.

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