Coating film for molding carbon fiber composites and its preparation method

Abstract

A coating film for molding carbon fiber composites and its manufacturing method are disclosed. The manufacturing method includes the following steps: preparing a substrate layer and a powder layer, wherein the powder layer is in powder form and its components include epoxy resin; spraying the powder layer onto the substrate layer to adhere the powder layer to the substrate layer, thereby obtaining a pre-treated material; hot-pressing the pre-treated material under hot-pressing conditions to melt and penetrate the powder layer into the substrate layer, thereby obtaining a prepreg fabric. Because the powder layer is in powder form, by spraying and adhering the powder layer to the substrate layer to obtain the pre-treated material, and then hot-pressing the pre-treated material, the powder layer can be melted and penetrated into the substrate layer, resulting in a smoother surface of the prepreg fabric, which is beneficial for the subsequent molding quality of coating the material to be coated with the prepreg fabric.

Claims

1. A coating film for molding carbon fiber composites, suitable for coating a material to be coated, the coating film for molding carbon fiber composites comprising: a prepreg fabric including a substrate layer and a powder layer, the thickness of the substrate layer being between 0.020 mm and 0.024 mm, the melting point of the substrate layer being between 110°C and 260°C, the powder layer melting and penetrating into the substrate layer, the powder layer being in powder form and comprising epoxy resin, the melting point of the powder layer being between 85°C and 130°C, and the area basis weight of the powder layer and the substrate layer being between 3:11 g / m² and 5:11 g / m².

2. The coating film for molding carbon fiber composites as described in claim 1, wherein, The substrate layer is made of non-woven fabric.

3. The coating film for molding carbon fiber composites as described in claim 1, wherein, The powder layer has several powder particles, each with a particle size between 25 μm and 50 μm.

4. A method for preparing a coating film for molding carbon fiber composites, comprising the following steps: a preparation operation, preparing a substrate layer and a powder layer, the thickness of the substrate layer being between 0.020 mm and 0.024 mm, the powder layer being in powder form and comprising epoxy resin; a spraying operation, spraying the powder layer onto the substrate layer to adhere the powder layer to the substrate layer, thereby obtaining a pretreated material; and a molding operation, hot-pressing the pretreated material according to a hot-pressing condition, thereby melting the powder layer and penetrating it into the substrate layer, thereby obtaining a prepreg fabric.

5. The method for preparing a coating film for molding carbon fiber composites as described in claim 4, wherein, The substrate layer is made of non-woven fabric.

6. The method for preparing a coating film for molding carbon fiber composites as described in claim 4, wherein, The powder layer has several powder particles, each with a particle size between 25 μm and 50 μm.

7. The method for preparing a coating film for molding carbon fiber composites as described in claim 4, wherein, In this preparation process, the area basis weight of the powder layer and the substrate layer ranges from 3:11 g / m2 to 5:11 g / m2.

8. The method for preparing a coating film for molding carbon fiber composites as described in claim 4, wherein, The melting point of the substrate layer is between 110℃ and 260℃, and the melting point of the powder layer is between 85℃ and 130℃.

9. The method for preparing a coating film for molding carbon fiber composites as described in claim 4, wherein, In this molding process, the hot pressing conditions have a hot pressing temperature between 85°C and 95°C.

10. The method for preparing a coating film for molding carbon fiber composites as described in claim 4, wherein, In this molding process, the pre-treated material is hot-pressed by a hot pressing device. The hot pressing device includes several rollers spaced apart along an operating direction. These rollers can rotate relative to each other along a conveying direction and respectively contact the two opposite sides of the pre-treated material along the operating direction to heat and roll the pre-treated material along the operating direction, so that the powder layer of the pre-treated material melts and penetrates into the substrate layer.

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