Vacuum Impregnation Technology
on Case of Making a Car Hood from Carbon Fiber

1. First of all, in the manufacture of the hood, we apply a release agent 2-3 times on the surface of the mold. After each removal, if necessary, the mold is again treated with a release agent.
2. After that, apply a 1mm layer of gelcoat to the matrix.
3. The first layer of fabric is being laid. All subsequent layers of fabric are fixed in the required position using spray adhesive or double-sided adhesive glass tape. If necessary, excess fabric is cut off.
4. The next step is to glue on the perimeter of the matrix flange at a distance of approx. 7-10 cm from the package a sealing tape, which will ensure the tightness of the structure when covered with a vacuum film.
5. A double-sided adhesive tape is then glued to the matrix flange between the sealing tape and the fabric layers approximately in the middle, on which a polyethylene spiral hose will be fixed, which makes it possible to constantly maintain the created vacuum. The spiral hose is fixed with double-sided adhesive tape.
6. Now we lay the sacrificial layer, in this case the flooring is made directly on the laid out fiberglass package. The spray adhesive also makes it possible to fix the sacrificial layer in this working stage.
7. Additional strips of sacrificial fabric are now cut and secured, which should facilitate the connection between the spiral hose and the part in order to ensure a flawless vacuum passage. In this case, spray adhesive finds use again. It is important that the sacrificial layer does not come into contact with the sealing tape, otherwise this may lead to a vacuum leak later.
8. Then lay down the resin dispenser. Fixation occurs with the help of aerosol glue. The resin spreader makes it possible to evenly distribute the resin throughout the part being made.
9. Resin flow channels are cut to the required length and placed on the resin dispenser. This product can be reused. The resin flow channels are fixed with adhesive tape.
10. Now we can cover the structure with a vacuum film. As a rule, the vacuum film is cut about 30-40% more than the design. This essentially depends on the contour of the part being made.
11. For precise positioning, the vacuum film is fixed first of all on the most important places of the sealing tape. The support paper is removed from the sealing tape and the film is pressed against the sealing tape. The remaining, open areas of the film are called folds or lugs. They are also closed with sealing tape. This requires certain skills. Let's see how it's done one more time.
12. Now we connect the PE tee to the PE coiled tubing and attach the one piece PE tubing. It serves as an influx of vacuum.
13. The tube in turn is connected to the resin trap. In this case, the vacuum is supplied to the structure, and at the same time, the possibility of resin entering the vacuum pump is excluded.
14. Resin tubes are connected to the resin flow channels and sealed under the vacuum film with sealant.
15. Before starting the resin supply, all resin supply hoses are first closed with clamps.
16. Now we start the vacuum pump. You can watch how the vacuum film is pressed against the structure. So, a complete vacuum has been reached. But in any case, we must be sure that the design is absolutely hermetic. To do this, we interrupt the connection between the vacuum pump and the resin trap and observe the vacuum reading, it should remain constant in any case. The absence of vacuum leaks is very important for this process.
17. After all the preparation is done, we can add the hardener to the resin and mix the two components well. The resin hoses are dipped into the resin tank and the first clip is removed.
18. Once the resin has reached the second and third resin flow channels, the first inlet is closed. Then the second and third clamps are opened. The resin flow channels had to be positioned so that the part to be made would be impregnated step by step.
19. The resin has reached the edge of the workpiece on one side, and now we can shut off the resin supply.
20. Once the resin has reached all the edges of the part to be made, the last resin tube can be plugged off. The part to be made remains until fully cured under vacuum.
21. After complete curing, the entire vacuum bag is removed.