In the infusion process, the dry reinforcing material is placed in a negative mold coated with release agents. Only synthetic resin or metal tools (molds) are used in this process. In the next step, a plastic film is placed over the edge for sealing attached to the mold and a vacuum is created. With the help of vacuum, the resin is drawn into the reinforcing material between the mold and the film and does not come into contact with the ambient air. Negative pressure through the cavity is used to initiate and promote flow of the resin and allow uniform impregnation of the fiber fabrics. Curing occurs at room temperature and takes several hours. After the resin has cured, the plastic film is removed and disposed of.
Vacuum infusion produces fiber composite parts with a smooth front and a slightly wavy back. The process is well suited for small series production.