Method very similar to the previous, but the closure of the mold is obtained by creating a vacuum in a chamber perimeter of the mold specially created with a vacuum of – 0.9 bar, then, in the part of the mold intended to produce the piece: another vacuum level to -0.5 bar shall be created; The catalyzed resin is injected from the outer perimeter and draws air through the center of the mold. With this system, taking advantage of the negative pressure in the vacuum, molds are light enough and much less expensive than the RTM Classical process.
The surfaces of the products are well-kept and beautiful on both sides, the quality of the pieces is excellent as the good fiber / resin ratio, and the molding system, given the low costs, and the process can also be applied to a few hundred pieces a year.