2.3. Injection Molding PA66 with glass fibers was processed by an injection molding machine (70 ton Negri Bossi, screw diameter 25 mm, L/D = 22) equipped with gas injectors that were connected to a volumetric pump and a screw with a mixing section. The mold was equipped with a hot runner with a gate valve. Nitrogen in supercritical state was adopted as physical blowing agent for the foam injection molding process.. The geometry of the cavity is reported in Figure 3.