Abstract: Numerical simulation and laboratory experiments were carried out to analyze two kinds of polystyrene plates with either semi-circle or rectangular gas channel. Based on the main processing parameters such as gas penetration length, gas channel shape, residue thickness, and gas channel defects, the evaluating standard of the quality of gas channel was established. For semi-circle gas channel, the radius was 2 times that of the plate wall thickness, and the quality of gas channel was the best. For rectangular gas channel, when the width of gas channel and the wall thickness kept constant, the quality of gas channel would improve with increase of the height and width of gas channel increased; when the height of gas channel was 2 times of the width of gas channel, and the width of gas channel was the 2 times of the plate wall thickness, the quality of gas bubble was the best.

Key words: gas-assisted injection molding, gas channel, optimal design, numerical simulation