Abstract
This paper proposes a new thread shape of aluminum beverage bottle in order to reduce the opening torque of bottle cap. Firstly, it is proved that the theoretical opening torque of the saw-toothed thread is smaller than that of the existing thread shape based on the calculation of the torque of the conventional threads. Then, a simulation of aluminum bottle model, thread shape of which is changed to the saw-toothed thread, is implemented by using a commercial software ANSYS. According to the simulation results, the opening torque can not be reduced due to the effect of skirt and contact range between bottle and bottle cap. So the new model is proposed whose skirt is also changed to the saw-toothed thread and whose contact surface of bottle is changed to line, contact surface of cap is changed to circle. The simulation results shows that the opening torque of the new model is reduced 12% compared with the existing bottle model. Finally, the optimization technology is applied to search optimum thread shape. It is confirmed that the thread contact angle between bottle and cap is the most important design factor for reducing opening torque and when the contact angle is zero degree, the opening torque reaches its minimum.
