A Study on the Opening Characteristic of an Aluminum Bottle and Effects of the Dimensions of the Bottle

Abstract

This paper studies the opening characteristics of aluminum bottles with screw caps. In order to examine the opening characteristic, opening experiments and measurements of friction coefficient and contact state between the bottle and cap have been performed. An analysis technique of estimating the 1st torque when unscrewing the cap is proposed in consideration of the experimental results. The estimation agrees with the measurement of the 1st torque in general. It is necessary to take the relation between the friction coefficient and contact pressure into consideration to improve the estimation accuracy. The influence rates of the seal part, the screw part and the skirt part to the 1st torque are about 60%, 25%, and 15%, respectively. It is obvious that the design space of the skirt angle needs to be reduced so that a stable value of the 1st torque can be expected.