Abstract
Removal torque of caps on child resistant packages (CRPs) with the press-and-turn closure, and on the polyethylene bottles and glass bottles with screw caps were investigated. The removal torque of the caps on CRPs and on polyethylene bottles decreased markedly on the first day and then gradually with time. Conversely, the removal torque of caps on glass bottles increased rapidly. The variations in the removal torque of cap ware observed to be dependent on storage temperature. These phenomena were attributed to the container and packing materials used. The results obtained concerning the break torques, return torques and the water vapor permeation which was examined in previous reports revealed that suitable applied sealing torquewas 20-30kg·cm. The press strength of the CRP cap exhibited a low value, confirming that the CRP used in this experiment was easy to use.
