In recent years, a variety of impregnation methods for continuous fiber reinforced high performance prepreg have appeared, such as melt impregnation method, solution impregnation method, powder curing impregnation method, powder suspension impregnation method, mixed preparation method, etc.
1. Foreign technology development status
Foreign research on continuous fiber reinforced high performance prepreg started earlier and is now in the stage of industrial production. At present, PEEK prepreg main suppliers are TenCate, Fiberforge, Victrex, Celanese and topunt nix, while PPS prepreg main suppliers are TenCate and Fiberforge.
Since 1982, Imperial Chemical Industries Ltd (ICI) has developed carbon fiber/polyether ether ketone unidirectional prepreg materials such as apc-1 and apc-2 by means of melt impregnation.
Ticona (Celanese) prepared high-performance unidirectional continuous fiber reinforced thermoplastic composite prepreg by melt impregnation method, as shown in figure 1.
Thermoplastic prepreg zone was successfully prepared by powder suspension impregnation in Augstin, Germany.
The production rate is 5m/min, and the fiber volume content of prepreg zone is 60%.
In addition, BASF, a French company, has also used this impregnation method to produce thermoplastic carbon fiber composites.
Tencate in the Netherlands and France.
FIG. 1 melt impregnation process
Atochem USES powder fluidized impregnation to prepare the powder prepreg tow.
The resin powder is then evenly coated on the surface of the fiber by means of a fluidized bed filled with 10 nm of micro powder.
Finally wrapped him in resin film, fiber Bundles by coated with resin Powder or Powder in tow (Powder Impregnated Bundles), which in tow, texture soft, can be woven into all kinds of fabric, after the shop is stuck into fixed shape through many layers, heat pressure can be made into composite material, use very convenient.
The fiber blending technology invented by NASA, USA, processes thermoplastic resin into microfiber, and then blends it with carbon fiber to make fabric to improve the wettability of resin and fiber, as shown in figure 2.
FIG. 2 mixed prepreg and its forming process
2. Domestic technology development status
Domestic research on the preparation technology of continuous fiber reinforced high performance thermoplastic composite prepreg has just started. At present, the industrialization is: glass fiber reinforced PP thermoplastic composite prepreg belt, which has been applied in rv, refrigerator, container and box-type freight car.
Other research achievements in China include: xian guijun et al. developed a small experimental device for dipping the thermoplastic prepreg zone of continuous fiber.
The device USES mechanical rollers to expand the fiber bundles, impregnates by melting, and finally yields a resin content of 40%.
70% continuous carbon fiber prepreg and continuous glass fiber prepreg.
Chen ping et al. studied the process of impregnating various fibers with PPESK resin solution by using solution impregnation method, and analyzed the effects of different parameters on the impregnation effect and the properties of composite materials.
Rao jun et al. impregnated the continuous carbon fiber in PPS powder and diphenyl ether ketone suspension, and prepared the prepreg with superior performance.
Zhang yiding et al. mixed PPS with water to form suspended liquid PPS mud to impregnate continuous fibers to prepare thermoplastic prepreg.
Zhou xiaodong et al. studied the powder impregnation process of continuous glass fiber, and the results showed that the powder impregnation effect increased with the decrease of powder particle size or the increase of the number of rollers.
Zhang feng-fan et al. used powder fluidization impregnation method to prepare the fiber bundles into thermoplastic prepreg strips, and set up a test device for preparing thermoplastic prepreg strips.
3. Industrialized technology
3.1 progress of domestic commercial thermoplastic prepreg
The domestic industrialized preparation method is to prepare prepreg strips of thermoplastic resin such as glass fiber reinforced PP, PA, PC and PE by the flow-extension method. At present, some manufacturers also make prepreg materials of carbon fiber prepreg PA or PEEK, but the downstream application reason of the system is not applied in batches.
At present, the most widely used in the market is the glass fiber PP prepreg, the main domestic mass production manufacturers are qiyi, beas, jie jie, tunnel gold, huaju, juner, goldilocks, jiwei and so on.