The gas in the mold includes not only the air in the cavity, but also the air in the runner and the decomposition gas produced by the plastic melt. During injection molding, these gases should be discharged smoothly.
1. The surface of the rubber parts is not clear due to the formation of drying marks, air blooming and seams;
2. Difficult filling or local flash;
3. When it is serious, there are scorch marks on the surface;
4. Reduce the filling speed and prolong the molding cycle.
Size of exhaust slot: two points should be paid attention to when opening exhaust groove:
1. At the same time of exhausting, the size design of exhaust tank should be able to prevent materials from overflowing into the tank.
2. Prevent the exhaust groove from blocking.
