Injection molding method of plastic frame and forming die used in same

The invention discloses an injection molding method of a plastic frame and a forming die used in the same. The injection molding method comprises an injection molding step, and is characterized in that in the injection molding step, molten plastics are injected into a die cavity through nozzles and a hot runner casting system by adopting a plastic injection molding machine, wherein, hot runner sprues in the hot runner casting system adopt a feeding mode on the end surfaces of the sides of the plastic frame. The forming die comprises a stationary die, a moving die, the die cavity and the casting system, and is characterized in that the hot runner casting system is arranged on the moving die, and the hot runner sprues are positioned on the die cavity to realize the feeding mode on the end surfaces of the sides of the plastic frame. The injection molding method has the beneficial effects that during the injection molding process of the plastic frame, no cold plastic scraps can be generated, thus saving raw materials, shortening the forming cycle, and improving the production efficiency; and meanwhile sprue marks are avoided on the front face of a plastic part product (the plastic frame), thus ensuring the appearance quality of the product.