The process of impregnation by spraying (spray-up process), is one of the most rapid in the advanced composite industry and is widely used in the fields of construction of components having large dimensions thanks to the use of special resins. The processing involves the use of an open mold within which is located a layer of gelcoat which guarantees a high quality color of the finished product. The process consists in spreading inside of the mold the glass fibers in jagged shape (chopped strand) and at the same time the resin catalyzed through a special grease gun; this allows to fill the mold in a rapid and uniform manner. After the spray, they are used spiked rollers or scrapers to remove the air introduced into the mold during processing. This technique, however, involves disadvantages that oppose to the low cost and simplicity in application. Among them the most important is their little weight because of the amount of resin that impregnated laminates and theirs poor mechanical and thermal properties.